Unit to control power inverter of dc conversion into ac of circuit of resonant power converter, in particular, dc converter into dc for use in circuits of high voltage generator of up-to-date device of computer tomography or x-ray system

FIELD: electricity.

SUBSTANCE: circuit of power conversion of resonance type comprises a phase-to-phase transformer (406), serially connected to at least one serially connected resonant circuit (403a and 403a' or 403b and 403b') at the outlet of two cascades (402a+b) of the power inverter of DC conversion into AC, supplying to the high-voltage transformer (404) with multiple primary windings. The phase-to-phase transformer (406) serves to eliminate mismatch (ΔI) of resonant output currents (I1, I2) of cascades (402a+b) of the power inverter of DC conversion into AC. The method of control guarantees that the phase-to-phase transformer (406) is not saturated, provides for operation under zero current and provides for minimised losses of power at the inlet.

EFFECT: provision of efficient control of supplied output power under zero current in each cycle of switching for elimination of losses.

16 cl, 9 dwg

 

The technical FIELD

The present invention relates to a control unit of the power inverter convert DC to AC current circuit of the power Converter resonant type, in particular, Converter DC to DC to supply power output, for example, for use in the circuits of the high voltage generator system of formation of radiographic images, devices, three-dimensional (3D) rotational angiography device or x-ray computed tomography type with the fan or cone beam. More precisely, the present invention is directed to a circuit of the power Converter resonant type, which contains interphase transformer, connected in series, at least one serially connected resonant circuit at the output of the two stages of the power inverter convert DC to AC current, feeding a high-tension transformer with multiple primary windings, in this case, the interphase transformer is used to correct the misalignment of the resonant output currents cascades power inverter convert DC to AC current. Additionally, the present invention relates to a method of control, which ensures that the interphase transformer is not saturated. This method of control is the exercise provides at zero current and provides that loss of input power can be minimized.

PRIOR art

Generators, high voltage power supplies x-ray tubes used in medical radiography, usually contain at least one multiphase transformer high voltage that provides the required power to operate the x-ray tube to the cathode and the anode. In the traditional circuits of the generators high voltage, the control unit of the AC voltage, for example, such as an autotransformer, brings the power line to a polyphase primary winding of the transformer high voltage. A switching device, such as a silicon triode thyristor (SCR) in connection with the bridge rectifier, opens and closes the neutral point of the star primary polyphase winding to turn on and off the supply of high voltage to the x-ray tube. Inductive and capacitive effects in the transformer and connected in the it components of the power supply usually causes a high voltage to rise above its steady-state level during the period immediately after opening the circuit. It is known that the significance of this excess increases with increasing voltage x-ray tube and decreases with increasing Tatarintseva tube. In particular, fed inverter with a shifted phase pulse-width modulation (PWM, PWM) power converters DC to DC with the parasitic resonant circuit of the high-tension transformer, used for x-ray power generator, thus, demonstrate the hard nonlinear characteristics due to the regulation of the out of phase voltage and the operation of the diode cutoff in high-voltage rectifier because of the wide range of installations load in specific applications.

Modern resonant frequency DC to DC such as used in the circuits of the high voltage generator to supply x-ray tube high voltage power supply, operate at high switching frequencies. It is obvious that any switching loss arising from associated power switches in a single cycle switching, should be reduced in order to limit the total power loss.

A recognized way of doing this is switching at zero current (ZCS), where the on and off power switches is only permitted on or near a zero crossing of the resonant current. This method is common practice in software controlled pulse converters, but has insufficient what it is he degrades the controllability of the output power. Switching at zero current and good handling are almost incompatible requirements, as good control is usually achieved continuous running time on state power switches, and in this case, ZCS cannot be guaranteed in all operating points. Therefore, there are switching loss, so between the switching losses and the controllability of the output power can be achieved compromise.

Recently, we developed a variety of high voltage pulse power supply DC using a resonant inverter with high frequency transformer-fed or voltage-fed current, bipolar power transistors (IGBT) MOS (metal-oxide-semiconductor (MOS) for x-ray generators, high power medical applications. In General, x-ray generators, high power and high voltage using fed by voltage high frequency inverters in connection via transformer connection of a high voltage must meet the following requirements: (i) a short period of increase in the starting transition voltage x-ray tube, (ii) does not exceed the transient response voltage is Oia on the tube and (iii) minimized ripple voltage in the periodic steady state in an extremely wide load fluctuations and fluctuations of the current filament x-ray tube.

Circuit high voltage generator for use in the device CT (computed tomography) or x-ray devices preferably consist of a serial resonant circuit for excitation of the high-tension transformer. Traditional power regulators, DC to DC, which are used in such circuits the high voltage generator, such as described in WO 2006/114719 A1, therefore, require that the modulator was commuting cascades power inverter convert DC to AC current that is different from each other, which leads to different resonant current cascade power inverter convert DC to AC current, working together on a single transformer with multiple windings. As a consequence, switching at zero current is no longer ensured for all operating points, resulting in the addition of unwanted losses. Traditionally, a special method of control is used to provide switching at zero current, at any time, along with support for high controllability of the output voltage. If you cast the water power inverter convert DC to AC current work, the method of control may result in an asymmetric distribution of currents. As a consequence, however, switching at zero current is no longer ensured for all operating points that cause unwanted losses.

A BRIEF STATEMENT of the substance of the INVENTION

The present invention is to propose an effective management input output power when operating at zero current in each cycle of switching, so as to avoid unnecessary loss.

To achieve this objective, the first rough version of the implementation of the present invention is directed to the control unit of the power inverter convert DC to AC current in the resonant circuit of the power Converter. Diagram of the power Converter, therefore, contains two independent cascade power inverter convert DC to AC power transformer with multiple primary windings, and the cascades of the power inverter convert DC to AC current is inductively related to the first and the second winding of the interphase transformer, which is designed to balance mismatches output currents of the two stages of the power inverter convert DC to AC current. In this regard, it should be noted, is that the resonant circuit of the power Converter may be implemented as a DC-to-DC constant current for use in the circuits of the high voltage generator, and that transformer with multiple primary windings may be designed for operation at high voltage. Circuit high voltage generator can be used to supply output power to the system is the formation of radiographic images, the device of the three-dimensional rotational angiography device or x-ray computed tomography type with the fan or cone beam.

According to the present invention, the control unit power inverter convert DC to AC current can be configured to minimize the value of the error output currents of the inverter to a value which ensures that the interphase transformer is not operating in a saturated condition, by controlling the States of the switching and/or points in time switching stages power inverter convert DC to AC current depending on the mismatch currents, thus ensuring that at zero current.

In this context, it should be noted that the first winding of the interphase transformer may preferably be connected in series, at least one resonant circuit connected in series to the first primary winding of the transformer with multiple windings on the output of the first cascade silverinventory convert direct current into alternating current, and the second winding of the interphase transformer may preferably be connected in series, at least one additional resonant circuit connected in series to the second primary winding of the transformer with multiple windings.

Additionally, the second exemplary variant of implementation of the present invention relates to a resonant circuit of the power Converter. As described above with reference to the first variant of implementation, the circuit of the power Converter contains two independent cascade power inverter convert DC to AC power transformer with multiple primary windings, and the cascades of the power inverter convert DC to AC current is inductively related to the first and the second winding of the interphase transformer, which is designed to balance mismatches output currents of the two stages of the power inverter convert DC to AC current. Again it should be noted that the resonant circuit of the power Converter may be implemented as a DC-to-DC constant current for use in the circuits of the high voltage generator, and the transformer with multiple primary windings may be designed to work on high the com voltage. Circuit high voltage generator can be used to supply output power to the system is the formation of radiographic images, the device of the three-dimensional rotational angiography device or x-ray computed tomography type with the fan or cone beam. According to the present invention, the resonant circuit of the power Converter may include a control unit of the power inverter convert DC to AC current, which can be configured to minimize the mismatch value of the output currents of the inverter to a value which ensures that the interphase transformer is not operating in a saturated condition, by controlling the States of the switching and/or points in time switching stages power inverter convert DC to AC current depending on the mismatch currents, thus ensuring that at zero current.

As described above, the first winding of the interphase transformer may preferably be connected in series, at least one resonant circuit connected in series to the first primary winding of the transformer with multiple windings on the output of the first cascade of the power inverter convert DC to AC current, and the second winding is Espanola transformer may preferably be connected in series, at least one additional resonant circuit connected in series to the second primary winding of the transformer with multiple windings.

The third exemplary variant of implementation of the present invention is directed to a system for forming x-ray images, the device of the three-dimensional rotational angiography or device x-ray computed tomography type with the fan or cone beam containing a diagram of a resonant power Converter for supplying an output power for use in the circuits of the high voltage generator, which provides the device computed tomography or x-ray system power supply voltage for the x-ray tube. Therefore, the circuit of the power Converter contains two independent cascade power inverter convert DC to AC power transformer with multiple primary windings, and the cascades of the power inverter convert DC to AC current is inductively related to the first and the second winding of the interphase transformer, which is designed to balance mismatches output currents of the two stages of the power inverter convert DC to AC current.

According to the present invention,the system of formation of x-ray images, the device is a three-dimensional rotational angiography or device x-ray computed tomography may include a control unit of the power inverter convert DC to AC current, which can be configured to minimize the mismatch value of the output currents of the inverter to a value which ensures that the interphase transformer is not operating in a saturated condition, by controlling the States of the switching and/or points in time switching stages power inverter convert DC to AC current depending on the mismatch currents, thus ensuring that at zero current.

As already described above, the first winding of the interphase transformer may preferably be connected in series, at least one resonant circuit connected in series to the first primary winding of the transformer with multiple windings on the output of the first cascade of the power inverter convert DC to AC current, a second winding of the interphase transformer may preferably be connected in series, at least one additional resonant circuit connected in series to the second primary winding of the transformer with multiple windings.

The fourth exemplary variant of implementation of the present invention relates to a method of controlling the resonant circuit of the power Converter for supplying an output power for use in the circuits of the high voltage generator system of formation of radiographic images, devices, three-dimensional rotational angiography device or x-ray computed tomography type with the fan or cone beam. As described above with reference to the second variant of implementation, the resonant circuit of the power Converter contains two independent cascade power inverter convert DC to AC power transformer with multiple primary windings, however, the cascades of the power inverter convert DC to AC current can be inductively related to the first and the second winding of the interphase transformer to balance mismatches resonant output currents of the two stages of the power inverter convert DC to AC current. Therefore, the second winding may be connected in series to the first primary winding of the transformer with multiple windings on the output of the first cascade of the power inverter convert DC to AC current, and the second winding may be in series is connected to the second primary winding of the transformer with multiple windings. According to the fundamental idea of the present invention, the method may include the stages, which continuously detects the resonant output currents of the two inverters for the initiated session radiography at balancing electric currents flowing on the outputs of the two stages of the power inverter convert DC to AC current by using interphase transformer, calculate the magnitude of the error currents obtained by subtracting the resonant current at the output of the second of the two stages of the power inverter convert DC to AC current of the resonant current at the output of the first of these two stages of the power inverter convert DC to AC current and control the States of the switching and/or points in time of the switching of the two cascades power inverter convert DC to AC current depending on the calculated error of the detected output currents of the inverter, so that the misalignment of the currents took a minimum value which ensures that the interphase transformer is not operating in a saturated state, thus ensuring that at zero current.

The fifth exemplary variant of implementation of the present invention relates to a computer program product for implementing the Oia method of controlling the resonant circuit of the power Converter, feed output power for use in the circuits of the high voltage generator system of formation of radiographic images, devices, three-dimensional rotational angiography device or x-ray computed tomography type with the fan or cone beam when working in the unit operational management of such system or device. As described above with reference to the second variant of implementation, the resonant circuit of the power Converter may contain two independent cascade power inverter convert DC to AC power transformer with multiple primary windings, and the cascades of the power inverter convert DC to AC current is inductively related to the first and the second winding of the interphase transformer to balance mismatches resonant output currents of the two stages of the power inverter convert DC to AC current, in this case, the first winding may be connected in series to the first primary winding of the transformer with multiple windings on the output of the first cascade of the power inverter convert DC to AC current, and at the same time, the second winding may be connected in series to the second primary winding of the transformer, with many winding is K. According to the present invention, a computer software product may be configured to perform steps, which calculates the mismatch currents obtained by subtracting the resonant current, detektirovanie at the output of the second of the two stages of the power inverter convert DC to AC current of the resonant current, detektirovanie at the output of the first of these two stages of the power inverter convert DC to AC current, and the currents symmetrist through an interphase transformer, and control the States of the switching and/or points in time of the switching of the two stages of the power inverter convert DC to AC current depending on the calculated error of the detected output currents of the inverter so that misalignment of the currents took a minimum value which ensures that the interphase transformer is not operating in a saturated state, thus ensuring that at zero current.

BRIEF DESCRIPTION of DRAWINGS

The invention is further explained in the description of the preferred variants of the embodiment with reference to the accompanying drawings, in which:

figure 1 shows a block diagram for illustrating the principal components multipulse generators high voltage is tion, which are widely used according to the prior art to provide supply voltage x-ray tube;

figure 2 shows the diagram of the feedback control to illustrate the principle of the control voltage x-ray tube and the tube current, which is known from the prior art;

figure 3 shows an analog implementation of the generator high-voltage type inverter according to the prior art, as described with reference to figure 1, which can be used in medical x-ray system;

figure 4 shows the analog circuit diagram of a resonant power Converter DC to DC current for supplying an output power for use in the circuits of the high voltage generator with two independent cascades power inverter convert DC to AC current, as known from WO 2006/114719 A1;

figure 5 shows the analog circuit diagram of a resonant power Converter DC to DC current for supplying an output power for use in the circuits of the high voltage generator system of formation of radiographic images, devices, three-dimensional rotational angiography device or x-ray computed tomography type with fan-shaped or conical beam, while the circuit of the power Converter DC to DC contain two independent cascade power inverter convert DC to AC current to the power transformer high voltage multiple primary windings, and the cascades of the power inverter convert DC to AC current inductively associated interphase transformer;

6 shows the truth table for all possible combinations of modes of operation for the two stages of the power inverter convert DC to AC current, working on a single transformer high voltage, as is known from WO 2006/114719 A1;

Fig.7 shows the truth table for the control algorithm, which can be done to minimize the observed mismatch of the two resonant output currents of the inverter, as proposed control method according to the present invention;

Fig shows two sinusoidal current waveform to the resonant output currents of the inverter, which are the result of applying one of a set of predefined modes, and the shape of the curve for the error output currents of the inverter;

Fig.9 shows a block diagram of the sequence of operations of the method to illustrate how to control the resonant circuit of the power Converter DC to DC current for supplying an output power for use in the circuits of the high voltage generator system of formation of radiographic images, devices, three-dimensional rotation and is geografii or x-ray computed tomography type with fan-shaped or conical beam, which is claimed in the present invention.

DESCRIPTION of the PREFERRED VARIANTS of the EMBODIMENT of the PRESENT INVENTION

In the following sections, the approximate variant of carrying out the scheme of the power Converter, DC to DC, as well as the approximate variant of carrying out the proposed control method according to the present invention will be explained in more detail with reference to the accompanying drawings.

Figure 1 shows the principle of the technology of the high-frequency inverter, which is also known as direct conversion of voltage. Because of this, she shows the principal components of the traditional multipulse generator high voltage used to power the x-ray tube 112. First of all, the intermediate voltageULPFDC with more or less ripple is generated by rectifying and filtering lower-frequency voltageUMainsalternating current, which is supplied by the mains supply, using cascade 101 AC to DC following the first cascade 102 filter the lower frequencies, the latter can be implemented in just a single smoothing capacitor. Although electric power output, as expected, b the children to be different, from single-phase power source can be obtained the same as high voltage, as from a three-phase power source. Cascade 103 power inverter convert DC to AC current, is connected with the cascade of 102 filter the lower frequencies, and then uses the intermediate DC voltage for forming a high-frequency AC voltageUinvfeeding the transformer 104 high voltage, which is connected on its secondary side to the high voltage rectifier 105 and the subsequent second stage 106 of the filter the lower frequencies, the latter can also be implemented by a single smoothing capacitor. The obtained output voltageUoutthen can be used as high-frequency multipulse voltage tube for generating x-ray radiation in the x-ray tube 112.

In this context, it should be noted that high frequency inverters typically use pulse-width modulation or act as a resonant circuit, depending on the power switches. Assuming that depicted circuit multipulse generator high voltage include reduction of the cross-section of the transformer core, the transformation of the high-frequency n is prajini AC gives a very small amount of a high-tension transformer. With such circuits, the voltage and current of the x-ray tube can be controlled independently, thus they are not exposed to fluctuations in the source voltage. Electronic control units voltage x-ray tube because of this, they typically demonstrate a response time of 0.1 MS or less.

Diagram of the feedback control to illustrate the principle of the control voltage x-ray tube and the tube current, which is known from the prior art, shown in figure 2.Typically, the effective value ofUactvoltage x-ray tube is measured and compared with a nominal value ofUnomselected by the operator at the control panel, in the comparison circuit. Depending on this information, the power switches are configured predefined manner (e.g., such as described in WO 2006/114719 A1). The performance of this control mainly depends on the frequency inverter. Although it is not as fast as generators high voltage with a constant potential, the inverter easily exceeds the performance of traditional mnogovekovyh rectifiers. Ripple in the output voltage on the secondary side of the transformer, mainly under the influence of the frequency inverter, internal smoothing capacitance, capacitance of the ignition the data cables and power level of the intermediate voltage ULPFDC.

Analog implementation of the generator high-voltage inverter according to the prior art, as described with reference to figure 1, which, for example, can be used in medical x-ray system shown in figure 3. As shown in figure 3, the AC voltage originating from the supply mains is rectified and smoothed by a full-wave rectifier 302 and a smoothing capacitor 303 in the intermediate DC voltage, and then served in the cascade 304 pornomotore power inverter convert DC to AC current, consisting of four bipolar key transistors high power. Moreover, fuse 305 is connected to one end of the input side of the circuit 304 of the inverter, and the detector 306 current connected to the other end of the circuit 304 of the inverter.

First of all, the input DC voltage is converted into high-frequency AC voltage (e.g., 200 kHz) through a scheme inverter 304. After the AC voltage is transformed into an AC voltage of a higher level (for example, 150 kV) through a transformer 307 high voltage, which is then rectified and smoothed high voltage rectifier 308 and a smoothing capacitor 309. Vysokomol the private rectifier 308 may be provided with a silicon diode with a breakdown voltage of 150 kV, and so In conclusion, the high DC voltage is applied to the x-ray tube 310. The resistor 311 dividing the voltage connected in parallel with the capacitor 309. As the value of the detection voltage of the tube (i.e., the values of the detection, the corresponding applied to the x-ray tube voltage), the voltage across the resistor 311 dividing the voltage is returned to the circuit 312 excitation inverter, which is used to control the temporal characteristics of the switching circuit 304 of the inverter.

In the schema 312 excitation inverter serves the value of detection of the detector 306 inverter current, the value of the detection voltage of the tube that is preset for installation of tube voltage and the setpoint (duration of exposure) to set the timer. These values are respectively inputted through the remote controller (not shown) of the x-ray system. As shown in figure 3, the circuit 312 excitation inverter generates an output signal which energizes the switching transistors of the circuit 304 of the inverter.

X-ray generators, high voltage or the generator high-voltage computed tomography preferably consist of cascades pornomotore power inverter convert DC to AC current, which is connected to a serial resonance to the tour for the excitation of the transformer high voltage (compare with figure 4). This diagram shows the analog circuit diagram of a resonant power Converter DC to DC current for supplying an output power for use in the circuits of the high voltage generator with two independent cascades power inverter convert DC to AC current, as known from WO 2006/114719 A1. Shows how two circuits 402a+b inverter can operate on a single transformer 404 high voltage with numerous windings. It can be shown that the size of the discrete intervals of output voltageUoutthe power Converter DC to DC can be reduced, resulting in even more low ripple output voltage. Due to the connection between the two resonant circuits common transformer, the function of the voltage divider. Instead of switching between the three modes, as described above in regard to the first exemplary variant of implementation of the present invention, there is achievable five significant modes. Five voltage levels generated by these modes, categorized +1, +1/2, 0, -1/2, -1, and have as a result of the combination of "+", "-" and "0" of the two independent inverters 402a+b.

To reduce losses, cascades power inverter convert DC to AC current before occhialino is switched at zero current. WO 2006 /114719A1, therefore, describes a control method which performs switching at zero current, under all circumstances, in combination with technically advanced controller for simultaneous control high output voltage.

Figure 5 shows a schematic diagram of two independently controlled cascades power inverter convert DC to AC current, whose outputs are connected in series to the serial resonance circuit and the first or the second winding of the interphase transformer, the latter provides the balancing currents between two independently operating cascades power inverter convert DC to AC current.

Here, the interphase transformer 406 provides the balancing of the output alternating currents the inverter as long as there was no phenomenon of saturation. At its core, the interphase transformer acts as an inductive voltage divider. As it has no air gap, misalignment of the output currents of the inverter is very little up until ensuring parallel operation of rectifiers transformer is not saturated. This current corresponds to the magnetizing current for a conventional transformer. Saturation may arise, if the integral over time of the voltage differences of the two cascades silo is on inverter convert DC to AC current exceeds the limit, a certain maximum policestation interphase transformer. When this happens, the error currents between the two cascades of the power inverter convert DC to AC current will increase.

To save the size of the interphase transformer 406 as small as possible, put the control algorithm to minimize the error currents the currents of the inverter, which leads to the fact that the integral of the voltage differential output voltages of the two stages of the power inverter convert DC to AC current time is minimized. Because of this, they can be saved all the benefits of the controller design described in WO 2006/114719 A1. In WO 2006/114719 A1, describes the three different modes of operation, indicated by the plus character (to increase the amplitude of the resonant current, for example, the mode having a voltage in phase with the resonant current), the symbol zero (e.g., mode, make zero voltage, and having the effect of maintaining the amplitude of the resonant current), and the minus symbol (to reduce the amplitude of the resonant current, for example, with a voltage opposite to the current).

Figure 4 (corresponding to 11, which is described in document WO 2006/114719 A1)is a schematic diagram of how the two schemes inverter can run on one is transformatora, with many windings. This provides the possibility of two additional modes switching, which is the result of a combination of state plus or condition minus one inverter with a status of zero in the other inverter. The resulting five levels are categorized as +1, +1/2, 0, -1/2 and-1. All possible combinations of operation modes having two cascaded power inverter convert DC to AC current, running on the same transformer high voltage shown in the table, which is presented on Fig.6 (corresponds Fig document WO 2006/114719 A1).

Obviously, there are some combinations that lead to the same current output voltage, but prepared differently. There is a redundant combination of 2 and 7, leading to level +1/2, and redundant combinations 4 and 9, leading to level-1/2, which lead to some degree of freedom to select potential models switching. Described later, the control algorithm uses these degrees of freedom to allow for some balancing currents of the inverter and, thus, reduces the risk of saturation of the interphase transformer. Also, there is a combination of 8 and 10, which are usually undesirable because they produce zero output voltage with the addition of switching losses in the Converter. Though the OC, what they are not considered here, in addition, they can also serve as conditions for balancing interphase transformers.

One method for balancing the currents of the inverter is to compare the error, for example, by subtracting the output current (I2the second inverter of the output current of the first inverter (I1with the help of a simple schematic of the operational amplifier and comparing it to zero, or a direct comparison of both signals. The resulting digital signal indicates which of the currents more. 7 shows a truth table which illustrates the proposed control algorithm to minimize the error currents.

From this table, it can be understood that the controller algorithm uses redundant modes of operation to control the cascades power inverter convert DC to AC current in some way, in which the resulting mismatch currents decreases. This, of course, is possible only for level +1/2 and-1/2.

On Fig shows two sinusoidal signali1(tandi2(tfor output currentsI1andI2, inverter, respectively, which are the result of the application of these modes, the preset output voltageU 1the first stage 402a power inverter convert DC to AC current, output voltageU2the second cascade 402b power inverter convert DC to AC current and output voltageUout'=f2'(U1,U2)claimed in the claims schematic 400 of the resonant power Converter DC to DC, as shown in the upper part of the drawing. At time of sampling,t=kT/2-ts(and,tskT/2, andk∈ ), it can be shown that the resulting mismatch ∆i(tbetween currentsi1(tandi2(t) inverter (here, between given their representations in the time domain) is greater or smaller than zero. If the controller requires a non-redundant mode of operation, such as a preset mode "+1", when both power inverter convert DC to AC current is switched to "+", then the control algorithm is not able to influence the symmetry of the currents. If the controller requires excessive state (e.g., +1/2), the control algorithm checks different currents to select a favorable combination of the operation modes of the inverter to minimize the above-mentioned different currents as can Bo the more. The remaining error is then compensated for by the interphase transformer. A particular advantage is that such an interphase transformer also balances the variation in other components and inequality between the inverter modules.

In this regard, it should be mentioned that the present invention is not limited to the circuits of the power Converter DC to DC with only two cascades of the power inverter convert DC to AC current, which should symmetricality being inductively related to the first and the second winding of the interphase transformer, which is designed to balance mismatches output currents of the two stages of inverter. May be mainly to assume that it should be symmetrical more than two cascaded power inverter convert DC to AC current by setting the appropriate number of interphase transformers for the inductive link outputs each pair of these cascades inverter. For a given number ofNcascades of the power inverter, it can be shown that, at least, (N-1) interphase transformers should be used for this task.

The block diagram of the operational sequence of the method to illustrate how to control the resonant circuit with the power Converter DC to DC current for supplying an output power for use in the circuits of the high voltage generator system of formation of radiographic images, device three-dimensional rotational angiography device or x-ray computed tomography type with fan-shaped or conical beam, which is claimed in the present invention, is shown in Fig.9. After receiving (S1) team switching (signal power) to initiate a new session radiography, resonant variables output currentsI1andI2two inverters continuously detects (S2b) at balancing (S2a) electric currents flowing on the outputs of the two stages 402a+b inverter convert DC to AC current by using interphase transformer 406. Otherwise, the procedure continues in a loop from step S1 through predefined time delay, ∆Iup until will not be accepted this team switching. In this case, is calculated (S3) the mismatch ∆Icurrents obtained by subtracting the resonance currentI2the output of the second (402b) of the two stages 402a+b inverter convert DC to AC current of the resonant currentI1the output of the first (402a) of the two stages of inverter convert DC to AC current, and next, which means, depending on the calculated misalignment ∆Ithe detected output currentsI1andI 2inverter-state switching and/or points in time of the two switching stages 402a+b of the DC/AC inverter is controlled in such a way that the mismatch currents takes a minimum value which ensures that the interphase transformer 406 is not operating in a saturated condition. When receiving (S5) team switching (signal off) to complete the work session radiography, the procedure ends. Otherwise, it continues with the steps S2a and S2b.

INDUSTRIAL APPLICABILITY

Direct application of the claimed circuit of the power Converter DC to DC is in development activity generators high voltage, in particular generators voltage with a very high energy density, which can mainly be used as a voltage source for x-ray tubes of the next generation. Except for this, the invention can also usefully be applied to the development of technology circuits of the power Converter DC to DC as a whole.

In this context, it should be noted that the required efforts on hardware and software for the implementation of this idea are low. Moreover, it should be mentioned that the proposed scheme the power Converter DC postoyanny current does not cause any additional switching losses.

Application of the interphase transformer, and a control algorithm that guarantees good simmetrichnuyu work cascades pornomotore power inverter convert DC to AC current.

Although the present invention has been illustrated in detail and described in the drawings and foregoing description, such illustration and description should be considered illustrative or exemplary and not limiting, which means that the invention is not limited to the disclosed variants of implementation. Other options for the disclosed embodiments can be conceptualized and implemented by experts in the field of technology in the implementation of the claimed invention to practice, study drawings, the disclosure and the accompanying claims. In the claims, the word "comprising" does not exclude other elements or steps, and the singular does not exclude a plurality. A single processor or other unit may fulfill the functions of several items set forth in the claims. The simple fact that certain criteria are listed in mutually different dependent claims does not constitute an indication that the combination of these criteria can not be used with benefit. The computer program may be stored/distributed is a suitable medium, for example, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication. In addition, any character references in the claims should not be construed as limiting the scope of invention.

1. The control unit of the power inverter convert DC to AC current circuit (400) resonant power Converter containing two independent cascade (a+b) power inverter convert DC to AC power transformer (404) with multiple primary windings, and the cascades (a+b) power inverter convert DC to AC current is inductively connected first and second windings of the interphase transformer (406)intended to balance mismatches in the output current (I1, I2two cascades (a+b) power inverter convert DC to AC current.

2. The control unit according to claim 1, in which diagram (400) of the resonant power Converter is a DC-to-DC constant current for use in the circuits of the high voltage generator.

4. The control unit according to claim 3, in which the circuit of the high voltage generator used to supply output power to the system is the formation of radiographic images, the device of the three-dimensional rotary angiography device or x-ray computed tomography with fan or cone beam.

5. The control unit according to any one of claims 1 to 4, in which the control unit of the power inverter convert DC to AC current is configured to minimize the value (ΔI) of the error output currents of the inverter to a value which ensures that the interphase transformer (406) does not work in a saturated condition by controlling the States of the switching and/or points in time switching stages (a+b) power inverter convert DC to AC current depending on the error (ΔI) currents, thus ensuring that at zero current.

6. The control unit according to claim 5, in which the first winding of the interphase transformer (406) connected in series, at least one resonant circuit (a, a'), are connected in series to the first primary winding of the transformer (404) with many windings on the output is, I can pay tithing of the cascades (a) power inverter convert DC to AC current, and in which the second winding of the interphase transformer (406) connected in series, at least one additional resonant circuit (403b, 403b'), serially connected to the second primary winding of the transformer (404) with many windings.

7. Diagram (400) of the resonant power Converter containing two independent cascade (a+b) power inverter convert DC to AC power transformer (404) with multiple primary windings, and the cascades (a+b) power inverter convert DC to AC current is inductively connected first and second windings of the interphase transformer (406), which is designed to balance mismatches in the output current (I1, I2two cascades (a+b) power inverter convert DC to AC current.

8. Diagram (400) of a resonant power Converter according to claim 7, in which diagram (400) of the resonant power Converter is a DC-to-DC constant current for use in the circuits of the high voltage generator.

9. Diagram (400) of the resonant power Converter of claim 8, in which the transformer (404) with multiple primary windings is designed to operate at a high voltage.

10. Diagram (400) of the resonant power Converter p is 9, in which the circuit of the high voltage generator used to supply output power to the system is the formation of radiographic images, the device of the three-dimensional rotary angiography device or x-ray computed tomography type with the fan or cone beam.

11. Diagram (400) of a resonant power Converter according to any one of claims 7 to 10, containing the control unit power inverter convert DC to AC current, which is configured to minimize the value of (I) the error of the output currents of the inverter to a value which ensures that the interphase transformer (406) does not work in a saturated state, by controlling the States of the switching and/or points in time switching stages (a+b) power inverter convert DC to AC current depending on the error (ΔI) currents, thus ensuring that at zero current.

12. Diagram (400) of a resonant power Converter according to claim 11, in which the first winding of the interphase transformer (406) connected in series, at least one resonant circuit (a, a'), are connected in series to the first primary winding of the transformer (404) with many windings on the output of the first of the cascades (a) power inverter convert quartering the nogo current into alternating current, and the second winding of the interphase transformer (406) connected in series, at least one additional resonant circuit (403b, 403b'), serially connected to the second primary winding of the transformer (404) with many windings.

13. The system of formation of radiographic images, the device of the three-dimensional rotational angiography or device x-ray computed tomography type with fan-shaped or conical beam containing the diagram (400) of the resonant power Converter for supplying an output power for use in the circuits of the high voltage generator, which supply the device computed tomography or x-ray system power supply voltage for the x-ray tube, the circuit (400) of the power Converter contains two independent cascade (a+b) power inverter convert DC to AC power transformer (404) with multiple primary windings and the cascades (a+b power inverter convert DC to AC current is inductively connected first and second windings of the interphase transformer (406), which is designed to balance mismatches output current (I1, I2two cascades (a+b) power inverter convert DC to peremennye.

14. The system of formation of radiographic images, the device of the three-dimensional rotational angiography or device x-ray computed tomography indicated in paragraph 13
contains the control unit power inverter convert DC to AC current, which is configured to minimize the value of (I) the error of the output currents of the inverter to a value which ensures that the interphase transformer (406) does not work in a saturated state, by controlling the States of the switching and/or points in time switching stages (a+b) power inverter convert DC to AC current depending on the error (ΔI) currents, thus ensuring that at zero current.

15. The system of formation of radiographic images, the device of the three-dimensional rotational angiography or device x-ray computed tomography in 14
in which the first winding of the interphase transformer (406) connected in series, at least one resonant circuit (a, a'), are connected in series to the first primary winding of the transformer (404) with many windings on the output of the first of the cascades (a) power inverter convert DC to AC current, and the second winding of the interphase, Transfo the matora (406) connected in series, at least one additional resonant circuit (403b, 403b'), serially connected to the second primary winding of the transformer (404) with many windings.

16. The way the control circuit (400) resonant power Converter for supplying an output power for use in the circuits of the high voltage generator system of formation of radiographic images, devices, three-dimensional rotational angiography device or x-ray computed tomography type with fan-shaped or conical beam, and the diagram (400) of the resonant power Converter contains two independent cascade (a+b) power inverter convert DC to AC power transformer (404) with multiple primary windings, and cascades (a+b) power inverter convert DC to AC current is inductively related to the first and second windings of the interphase transformer (406) to balance mismatches resonant output current (I1, I2two cascades (a+b) power inverter convert DC to AC current, the first coil connected in series to the first primary winding of the transformer (404) with many windings on the output of the first of the cascades (a) power inverter conversion constant is th current into alternating current, and the second winding is connected in series to the second primary winding of the transformer (404) with many windings, the method includes the steps are:
- continuously detects (S2a) resonant output current (I1, I2two inverters for the initiated session radiography at balancing (S2b) electric currents flowing on the outputs of the two cascades (a+b) power inverter convert DC to AC current through the use of an interphase transformer (406),
- calculate (S3) the magnitude of the error (ΔI) currents, which is obtained by subtracting the resonant current (I2the output of the second (402b) of the two cascades (a+b) power inverter convert DC to AC current of the resonant current (I1the output of the first (a) of these two cascades (a+b) power inverter convert DC to AC current, and
- control (S4) States of the switching and/or points in time of the switching of the two cascades (a+b) power inverter convert DC to AC current depending on the calculated error (ΔI) of the detected output current (I1, I2) inverter so that the current mismatch takes on a minimum value which ensures that the interphase transformer (406) does not work in NASA the hinnon condition, thus ensuring that at zero current.



 

Same patents:

FIELD: electricity.

SUBSTANCE: invention relates to a design of a high-voltage transformer, which comprises a primary flat winding (4, 8), a secondary winding (10) of an RF cable type, a core and a coil, having multiple slots, where the RF cable-type winding is wound, at the same time surfaces of flat windings rest against flat surfaces of the core. At the same time the windings of the high-voltage transformer may be exposed to a significant thermal stress during operation, since the proposed structure has high heat exchange properties due to the fact that the flat primary winding rests against the flat surface of the core (2), thus providing efficient heat exchange between these two elements, besides, the multi-cored secondary winding and the flat primary winding may be cooled with the help of a cooling medium.

EFFECT: improved efficiency of high-voltage transformer cooling is the technical result of the invention.

8 cl, 6 dwg

FIELD: x-rays.

SUBSTANCE: x-ray machine for generating short x-ray pulses consists of an x-ray tube, which has a heated cathode, anode and an x-ray generator. The x-ray generator has a primary circuit for generating a high voltage pulse, connected to the anode so as to generate an x-ray pulse. The x-ray generator also has a secondary circuit, through which a low voltage is constantly applied to the anode. The low voltage is at least sufficient for generating low energy x-rays and provides for preheating the x-ray tube. The primary circuit is a Marx generator and the secondary circuit is a power supply unit for preheating and is also used as a voltage source for the Marx generator.

EFFECT: possibility of generating x-ray pulses in the millisecond range, as well as the possibility of forming an image with a contrast outline using relatively low energy radiation.

10 cl, 3 dwg

X-ray equipment // 2316156

FIELD: x-ray engineering, possible use for controlling objects by means of x-ray radiation.

SUBSTANCE: in accordance to the invention, equipment may be connected to any voltage (1) of electric power supply, independently from voltage value within range 90-264 V, while electric power of equipment is fed into universal source (8) of alternating/constant current voltage, and also to controllable transformer (2) of current and to equipment (9) for adjusting input voltage, a set of capacitors (4) is charged at constant voltage, which is independent from electric supply voltage (1), where charging of aforementioned set of capacitors (4) may be performed in programmed way by means of input current programmer (3), to which end aforementioned input current programmer (3) influences controllable current transformer (2) in such a way, that charging of a set of capacitors (4) may be performed in sufficiently fast manner, preventing dips in the network, caused by charging of capacitors, and also overload of connection to powering electric network, aforementioned set of capacitors has an inverting power amplifier (5) connected to it, output of which is connected to high voltage transformer (6), and also, x-ray equipment has devices responsible for estimation of input voltage, and on basis of the latter - activation relays (10), which may be conventional or solid and which correspond to points of connection of powering transformer (12) of auxiliary equipment, for example, markers (13), arresters (14), collimators (15) and ionization chambers (16), without necessity of conduction of any manual measurement in electric supply feed depending on network voltage, where powering transformer (12) is analogically controlled by means of control block (11).

EFFECT: possible usage of x-ray equipment independently from electric power voltage and frequency supply, and also avoided dip of electric network power.

1 dwg

FIELD: electrical engineering; high-voltage electronic equipment including roentgen-ray emitters.

SUBSTANCE: proposed high-voltage transformer has low-voltage components incorporating primary low-voltage winding and insulated from high-voltage components incorporating high-voltage secondary windings. Zero potential level or ground level of high-voltage components is in their middle region between first end in whose direction negative potential rises and second end in whose direction positive potential gradually rises. High-voltage components are disposed in similar way as high-voltage secondary windings so that the latter and high-voltage components are placed at equal potential and are equally spaced from zero potential level or ground level. High-voltage components placed at lowermost potential are disposed close to one another and those placed at highest potential are spaced apart as far as possible. Low-voltage primary winding is disposed on first leg of magnetic core and high-voltage secondary winding, on its second leg.

EFFECT: reduced size and cost, facilitated installation and wiring.

4 cl, 3 dwg

FIELD: electricity.

SUBSTANCE: control device for transformer substations (5, 6) in high-voltage installation (1) of DC transfer comprises a unit (12) of rectifier control and a unit (13) of inverter control to control transformer substations that operate accordingly as a rectifier (5) and an inverter (6). Firing angles of accordingly the rectifier (5) and the inverter (6) are set and adjusted with the help of the units (12, 13). Between the units (12, 13) there is a delay link (20), with the help of which the start-up torque for adjustment of the inverter (6) firing angle is delayed relative to the start-up torque for adjustment of the rectifier (5) firing angle for the specified delay time (Δt).

EFFECT: provision of relatively quick transition from initial operating condition into new established operating condition.

3 cl, 2 dwg

FIELD: electricity.

SUBSTANCE: application: in the field of electrical engineering. Electricity transmission system comprises electric substation-rectifier (2) and electric substation-inverter (3), every of which has a serial connection of at least two converters (6-9). Bypass switch (12-15) is connected parallel to each transformer. Control device (22-25) is arranged with the possibility to unblock blocked transformer by means of its control start with a larger delay angle and gradual reduction of delay angle until all direct current flows via this converter, and further control of mentioned bypass switch for opening at zero current and also for stopping of mentioned converter by means of its control with a gradually rising delay angle until voltage on this converter becomes zero, and for further control of converter subject to blocking, by means of connection of its bypass pair, and further control of mentioned bypass switch for its closure with the purpose to receive all of the current, when voltage between zero bus (11) and pole (10) of power transmission line between mentioned electric substations shall accordingly be increased or decreased.

EFFECT: reliability improvement.

14 cl, 2 dwg

FIELD: electric-train drives using traction induction motors supplied with power from systems incorporating current inverters.

SUBSTANCE: proposed drive is characterized in that its power supply system has single-section input filter incorporating reactor Lf connected to contact system through high-speed switch HS and pneumatic contactor PC-1, as well as resistor R3 connected in parallel with the latter and two series-connected capacitors Cf1 and Cf2; connected in parallel with each of capacitors is thyristor voltage limiter TVL1 and TVL2, respectively; connected in series with each of the latter is braking resistor Rb1 and Rb2, respectively; positive plate of capacitor Cf1 is connected to input of thyristor chopper TC1 and negative plate of capacitor Cf2, to output of thyristor chopper TC2; output of thyristor chopper TC1 and input of thyristor chopper TC2 are connected through respective inverse diodes VD15 and VD25 to midpoint of capacitor bank Cf1-CF2; connected to output of thyristor chopper TC1 through smoothing reactor Lc1 is input of off-line current inverter OLCI1) whose output is connected through pneumatic contactor PC2 and parallel circuit set up of resistor R13m thyristors VS71.2 and VS71.1, resistor R14 to input of similar off-line current inverter OLCI2 made in the form of three circuits whose output is connected through smoothing reactor Lc2 to input of thyristor chopper TC2; output of off-line current inverter OLCI1 is connected to positive plate of capacitor Cf1 through diode VD12; input of off-line current inverter OLCI2 is connected through diode VD22 to negative plate of capacitor Cf2.

EFFECT: improved characteristics of device.

5 cl, 5 dwg, 1 tbl

The invention relates to the field of electrical engineering and can be used in drive systems with adjustable inverter

The invention relates to a Converter equipment and can be used to create transformative substations for transmission and inserts DC electrified Railways, electrical and metallurgical and chemical industries, which require powerful converters three-phase AC to DC or DC to three phase, and it is necessary to ensure operation of the Converter without the use or with the issuance of reactive power

FIELD: electricity.

SUBSTANCE: converter with a higher frequency link comprises a single-phase inverter bridge with back-to-back diodes, a transformer, a rectifier, two control systems, one of which controls operation of inverter transistors. The rectifier is arranged as diode with a zero point and is loaded to the resonant circuit. In parallel to the resonant circuit, a thyristor is connected, which is joined to the second control system. When controlling the converter, an interval t1 of transistor control pulses, where a positive half-wave of current is generated in a load, is alternated with an interval t2 of a zero pause, in process of which with the help of the first control system all transistors of the inverter are closed, with the help of the second control system the thyristor connected in parallel to the resonant circuit, is unlocked, providing for the mode of double conductivity of inductor current and generation of the negative half-wave of load current. The interval of inverter control pulses supply is always lower than the interval of zero pause, in which the thyristor is closed (t1<t).

EFFECT: reduced number of thyristors and lower voltages at thyristors and diodes to double output voltage of a transformer due to provision of inductor current continuity.

4 cl, 2 dwg

FIELD: electricity.

SUBSTANCE: conversion device for induction heating based on a parallel bridge resonant inverter comprises two valve bridges on four controlled valves with DC and AC diagonals, parts of a throttle of an oscillating circuit, a source of supply, two capacitors, a double-winding inductor, semi-windings of which are arranged on a side surface of a crucible along the axis of the inductor and perpendicularly to this axis in an alternating sequence. In a control system in process of charge melting high-frequency single-phase electromagnetic field is generated, and in process of electromagnetic mixing and heating of a melted metal, double-frequency double-phase electromagnetic field is generated: low-frequency electromagnetic field with high-frequency modulation. By low frequency the electromagnetic field generated by the second valve bridge is shifted by 90° el. relative to the first valve bridge.

EFFECT: generation of a high-frequency single-phase electromagnetic field at the stage of metal melting and double-frequency double-phase electromagnetic field at the stage of electromagnetic mixing of melted metal and its heating with one conversion device, simplification and reduction of losses.

2 cl, 2 dwg

FIELD: electricity.

SUBSTANCE: in a method of inverter control in process of switching of inverter valves, a voltage level is set on the valves, instantaneous voltage values are measured on the valves, as well as an instantaneous AC value in a load, moments of instantaneous AC value transition through zero are identified, sync pulses are generated with duration δ, corresponding to the interval [π/180, π/90], in the moments of instantaneous AC value transition in a load through zero, another control pulses are generated and sent, and another valves are connected not earlier than on the moments of the instantaneous AC value transition in a load through zero, control pulses are removed from valves, and valves are switched off with anticipation by an angle γ in the interval [π/45, π/6] in respect to moments of instantaneous AC value transition in a load through zero. At the same time instantaneous voltage values are compared on valves, which are subject to another connection, in the range δ of sync pulses action with the specified voltage level on the valves, and supply of another control pulses is prohibited, if instantaneous voltage values on another valves exceed the specified voltage level on the valves in the range δ of sync pulses action.

EFFECT: higher reliability of operation.

3 dwg

FIELD: electricity.

SUBSTANCE: in control method of frequency converter with three-phase fully-controlled bridge rectifier and two-contact consistent inverter with resonant commutation and load in the form of parallel oscillating circuit of the first type there supplied in turn are double control pulses shifted between each other through angle φ=60°, duration τ, with α adjustment angle, to valves of rectifier and inverter, thus forming direct and return on-load voltage half-waves. At adjustment angles α>60 there supplied in turn to each adjacent valve, to the main rectifier valve which was actuated after all the others, is the third control pulse at the angle corresponding to adjustment angle of the main rectifier valve α=120°, with duration γ≤τ. Maximum adjustment angle is set on the basis of α≤90°-τ. Instantaneous voltage values are measured on capacities of filter, parallel oscillating circuit of load and all valves of inverter. The next inverter valves are actuated when positive instantaneous voltage is recovered on all inverter valves. Inverter valves are deactivated when the decreasing module of instantaneous voltage value on capacity of parallel oscillating load circuit is equal to instantaneous voltage value on filter capacity.

EFFECT: improving operating reliability of frequency converter.

2 dwg

FIELD: electric engineering.

SUBSTANCE: invention relates to electric engineering and may be used for induction heaters and other electric technology loads. The control method for stand-alone harmonised inverter with resonance switching of controlled gates, provides for the source of direct supplying voltage E at the input, parallel oscillatory circuit with high Q-factory in the interval [1, 30], additional throttle with induction kL, where k is a numerical coefficient taking values within the interval [1/2, 5], and L is an equivalent induction of the load, that generate and alternately supply control pulses to control gates generated direct and inverted semi-waves of alternating voltage under the load, and define moments of instantaneous value of alternating voltage under the load transfer through the zero value. The next control pulses are controlled and supplied, and the next controlled gates are connected in advance of and with regard to the moments of instantaneous alternating voltage under the load values transfer through the zero value to the interval angle [π/12, π/3]. Then, voltage and instantaneous value of a.c. load current i are measured. The moments of instantaneous alternating voltage under the load value transfer through the zero are defined by solving equations equivalent to the given: E-kL di/dt=0.

EFFECT: extended area of stand-alone harmonica inverter with resonance switching application.

2 dwg

FIELD: electric engineering.

SUBSTANCE: invention relates to electric engineering and may be used for induction heaters and other high frequency electric technology loads. The stand-alone harmonica inverter with quazi-resonance switching includes a single-phase bridge on controllable gates with parallel opposed diodes 7-10 connected to inverter's input pins 3-6 through the filter 1,2 throttles. The single-phase bridge is shunted by the filter 11 capacitor, and a.c. output pins of this bridge is coupled with output pin of inverter through the switching throttle 12. The output pins of inverter are shunted with compensating capacitor 13 and connected to the load 14, while the second a.c. output pins of single-phase bridge is connected with the second output pin of inverter through the second switching throttle 15. The switching throttles are implemented as magnet-related and connected harmoniously. He controlled gates are shunted by switching capacitors 16-19, while the a.c. output pins of single phase bridge pins are shunted with snubber capacitor 20.

EFFECT: improved reliability of stand-alone harmonica inverter with quazi-resonance switching operation.

2 dwg

FIELD: electricity.

SUBSTANCE: device (1) for connecting stand-alone voltage inverter (2) to direct current voltage source (3) contains main components: reactor (4), input capacitor (5) of inverter, inverter input capacitor charge control unit (6), circuit (16) for limiting overvoltages in the form of damping circuit containing resistor (17) in parallel to which switch (18) is connected, and damping capacitor (19), as well as connected in series the first (26) and the second (27) diodes and electronic switch (29) connected in parallel to the second diode. In parallel to serial connection of the second diode (27) and reactor (4), switch (28) is included.

EFFECT: multiple reduction of inductance of electric circuit sections connecting inverter input capacitor outputs and outputs of contained in it electronic switches and bypass diodes shunting them, as well as voltage ripples at outputs of inverter solid-state power components and power losses in these components.

5 dwg

FIELD: electricity.

SUBSTANCE: in a method to control a resonant inverter with anti-parallel diodes a minimum value is specified for duration of an interval of conducting condition of an antiparallel diode equal to the time of thyristor disconnection. If the duration of the interval of the conducting condition of the anti-parallel diode reduces below the specified minimum value, control sequences of pulses are selected and generated, providing for increased duration of the interval of the disconnected condition of the thyristor.

EFFECT: increased reliability due to provision of switching stability of operation of a thyristor resonant current inverter.

2 tbl, 2 dwg

FIELD: electric engineering.

SUBSTANCE: main circuit of double-frequency aperiodic conversion device comprises DC voltage source, two filter throttles, three controlled valves, two windings of inductor load and two capacitors, at the same time the first pole of DC voltage source is connected to the first output of filter throttle, the second output of which is connected to the first outputs of three controlled valves, at the same time the second output of the first controlled valve is connected to the first outputs of the first winding of load inductor and the first capacitor, the second outputs of which are connected to the second output of the second controlled valve, and also with the first outputs of the second winding of load inductor and the second capacitor, the second outputs of which are connected to the second output of the third controlled valve, at the same time the second output of the second controlled valve is connected to the first output of the second filter throttle, the second output of which is connected to the second output of DC voltage source, at the same time load inductor is arranged of two windings located along length of load inductor, at the same time windings of load inductor are connected as matched and serial to each other, and controlled valves are connected in straigh direction relative to polarity of DC voltage source. In case of repeated opening and closing of the first and second controlled valves, in the first winding of load inductor several periods of electromagnetic field high-frequency components are generated, and also "pack" of these periods generates the first half-cycle of low-frequency component of electromagnet field. If the second and third controlled valves are opened and closed same number of times, then high-frequency component of electromagnetic field is also generated in the second winding of load inductor, and also "pack" of these periods generates the second semi-cycle of low-frequency component of electromagnetic field. A version of device is also proposed with inductance-capacitance circuit adjusted for frequency of low-frequency component of electromagnetic field. Versions are also provided for aperiodic conversion devices made of two and three devices arranged according to the first version, in which double-phase or three-phase double-frequency electromagnetic field is generated due to phase shift achieved by law of controlled valves control, and this field provides for efficient induction heating and melting of metal and its efficient electromagnet mixing.

EFFECT: simultaneous generation of high-frequency and low-frequency components and simplification.

4 cl, 4 dwg

FIELD: electric engineering.

SUBSTANCE: main circuit of double-frequency resonant conversion device comprises DC voltage source, the first, second, third and fourth throttles, the first and second controlled valves, the first and second diodes, the first and second windings of load-inductor, and also the first and second capacitors, at the same time the first pole is connected to the first output of the first throttle, the second output of which is connected to the first outputs of the third and fourth throttles, the second outputs of which are connected to the first outputs of the first and second controlled valves, the second output of the first controlled valve is connected to joined first outputs of the first capacitor and the first winding of load-inductor, the second outputs of which are also connected to each other and are connected to the first output of the second throttle, the second output of which is connected to the second pole of DC voltage source, at the same time the second output of the second controlled valve is connected to joined first outputs of the second capacitor and the second winding of load inductor, the second outputs of which are connected to each other and to the second outputs of the first capacitor and the first winding of load inductor, at the same time the first and second diodes are connected as opposite and parallel accordingly to the first and second controlled valves, at the same time the first and second windings of load inductor are connected as matched and serial to each other. When opening and closing first the first controlled valve and then the second controlled valve for several times, high-frequency and low-frequency components of electromagnetic field are generated in the first and second windings of load-inductor. Two versions are built on the basis of the main circuit of conversion device, let us call it conversion unit, and one of versions consists of two conversion units, and the second one - of three conversion units. In the first version due to shift of electric low-frequency component of electromagnetic field by 90° in the second conversion unit relative to the first one in the first, second, third and fourth windings of load inductor, simultaneously high-frequency electromagnet field and double-phase low-frequency field are generated. In the second version due to shift of electric low-frequency component of electromagnetic field by 120° in three conversion units relative to each other in the first, second, third, fourth, fifth and sixth windings of load inductor, simultaneously high-frequency electromagnet field and three-phase low-frequency field are generated.

EFFECT: simultaneous generation of high-frequency and low-frequency electromagnet fields and simplification.

3 cl, 3 dwg

FIELD: electricity.

SUBSTANCE: device comprises the main and the reserve AC circuit of 3-50 Hz, 380 V, the first, second and third switchboard, the first, second and third filter, the first and second rectifier, the first and second current sensor, an inverter, a transformer, a group of stabilised DC voltage consumers, a power supply unit, a unit of power switch drivers, a temperature sensor, a voltage sensor, a microcontroller, a control and indication panel, a unit of fans and an external system of remote control and monitoring, the device includes a limiter of start-up current, and the microcontroller is made as capable of monitoring the voltage value of the first and second AC circuit 3-50 Hz, 380 V, monitoring of the current value at the inverter inlet, monitoring of actuation in the unit of protection and the unit of power switch drivers by high current in open thyristors of the inverter, monitoring of the value of voltage and current of consumption by the group of stabilised DC voltage consumers, and with the possibility for control of the first, second and third switchboard, control of the unit of power switch drivers.

EFFECT: higher stability of output DC voltage and reliability of functioning of the proposed intelligent voltage converter during operation in a wide range of environmental temperatures, including minus ones.

2 cl, 1 dwg

Up!