Multilevel power converter
FIELD: physics, instrument-making.
SUBSTANCE: invention relates to conversion equipment. Base phase circuit U comprises semiconductor elements (SU1.1-SU1.4) from first through fourth, connected between the lead of a positive electrode and the lead of a negative electrode of a DC voltage source (DCC1), a fifth semiconductor element (SU1.5), having a connection with the common connection point of the first and second semiconductor elements (SU1.1, SU1.2), and a sixth semiconductor element (SU1.6), having a connection with the common connection point of the third and fourth semiconductor elements (SU1.3, SU1.4). A floating capacitor (FC1) is connected between the fifth semiconductor element (SU1.5) and a sixth semiconductor element (SU1.6). Voltage selection circuits as input terminals have common connection points of the second and third semiconductor elements (SU1.2, SU1.3) of corresponding base circuits and comprise, between the input terminals and the output terminal (U, V, W), semiconductor elements (SU1-SU4).
EFFECT: in a multilevel power converter, arbitrary voltages of all phases can be applied at the output, wherein control needed to apply arbitrary voltage levels of all phases is easier.
18 cl, 30 dwg, 2 tbl
SUBSTANCE: in the power conversion system for the Diesel locomotive auxiliaries comprising an auxiliary three-phase synchronous generator with a rectifier connected to its output and converting three-phase current to direct current, DC consumers are connected to a direct-current-mains, while AC consumers for the Diesel locomotive auxiliaries are connected through semiconductor converters, the three-phase rectifier is made as a four-quadrant semiconductor converter, which power IGBT-transistors in the power circuit are connected directly to the output of the auxiliary three-phase synchronous generator and in a control circuit they are connected to a vector control unit in a coordinate system rotating synchronically with an output voltage vector of the auxiliary three-phase synchronous generator and inputs of the above unit are connected to sensors for input linear voltage, two sensors of input phase current and a sensor for output direct voltage of the four-quadrant semiconductor converter.
EFFECT: expanded functionality of the Diesel locomotive notwithstanding positions of the driver's controller, generation of stable direct voltage for auxiliaries and operation in nominal conditions, simplified design of the Diesel locomotive and power supply for the auxiliaries of the second and third sections from the operating section of the Diesel locomotive, increased efficiency factor of the auxiliary three-phase generator and AC-DC rectifier.
SUBSTANCE: common output lead of auxiliary keys is connected to the midpoint formed by two filter capacitors of direct current, at that power modules based on integrated transistors (IGBT) are used as the auxiliary keys and control inputs of these modules are connected to outputs of control pulse decoders of the auxiliary keys while inputs are connected to outputs of the respective decoders of the auxiliary keys; between the common output of the auxiliary keys and the midpoint of the filter capacitors an additional capacitor may be coupled; duration of a switched on state of the auxiliary keys for the respective inverter phases at cosφH=0.98 and less is set as 0.06T, and at cosφH=0.98-1.0 it is set as 0.052T.
EFFECT: reducing distortion the factor by 1,8 times at change in cosφH from 1,0 up to 0,6 within the whole range of the load change at frequencies of 400 and 200 Hz.
3 cl, 2 dwg
SUBSTANCE: converter assembly comprises bidirectional non-insulated DC voltage converter (2), DC voltage converter (3) with galvanic insulation between input and output and control system, low-voltage accumulator battery (5), common high-voltage DC link (6), at least one converter coupled to AC machine, at least two controlled switches (4) and control system. The control system is designed so that controlled switches (4) are closed at transmission of energy by bidirectional non-insulated DC voltage converter (2) in direction from its input up to its output and open at of energy in reverse direction.
EFFECT: ensuring effective bidirectional conversion of energy and insulation of circuits related to accumulator battery from DC link in the transmission mode from DC link to the accumulator battery.
16 cl, 8 dwg
SUBSTANCE: multilevel DC/AC converter contains three inputs (IN1, IN2, IN3) of direct current to receive three voltages (V1, V2, V3) respectively, so that V1>V2>V3, one alternating-current output (OUT1) to transfer alternating voltage (Va), a group of at least six switching elements (T1, T2, T3, T4, T5, T6) placed as a symmetrical pyramidal scheme as specified in Fig. 1, and a switching control scheme to control the ON/OFF state of each element out of the six switching elements. The switching control scheme is configured so that switching ON and OFF of the two uppermost elements in the scheme (T5, T6) is made in a complimentary way, exclusively with the main frequency (Fa) of the alternating voltage transferred to an output (OUT1) of the alternating current, while switching (ON) and OFF at least for some of the remaining switching elements (T1, T2, T3, T4) is made at a higher frequency. In result, the above two uppermost elements (T5, T6) in the scheme introduce lesser losses for switching, thus increasing the total efficiency of the converter.
EFFECT: increasing the total efficiency of the converter.
6 cl, 9 dwg
SUBSTANCE: multilevel power converter supplying synchronous and asynchronous motors from a high DC voltage source includes output inverter-recovery modules, each of them containing the first high-frequency bridge and the second bridge and a capacitor. DC current circuits of the first and second bridges are connected in parallel to the capacitor, AC current circuit of the second bridge is connected in series to AC current circuits of the second bridges of another output inverter-recovery modules so that wye-connected groups and the first and second high-frequency transformers and input inverter-recovery modules as well are formed, each of the latter containing a high-frequency bridge and a capacitor. The DC current circuits of the bridge are connected in parallel to the capacitor. The AC current circuits of the bridges in input inverter-recovery modules and the first bridges in output inverter-recovery modules are interconnected in parallel through the high-frequency transformers; the DC current circuits of the bridges in the input inverter-recovery modules are connected in series while outputs of the received circuit are connected to the high DC voltage source.
EFFECT: invention allows the technical result that lies in the reduced weight and dimensions and increased efficiency factor of the converter at operation from the line of high direct voltage.
SUBSTANCE: invention relates to electrical engineering and can be used for converter control. In the method of forecasting of sequence of switching with pulse-width modulation for the multiphase multilevel converter in the first predicted sequence of switching because of multiphase redundancy the equivalent sequences of switching are determined. One sequence of switching is selected from equivalent sequences of switching, optimum with reference to the intended optimisation purpose. The selected sequence of switching is used for the converter switching.
EFFECT: improvement of balancing of internal state of the electric converter operated by the method of pulse-width modulation.
14 cl, 10 dwg
SUBSTANCE: device containing a load, the first and second input terminals, the first and second output terminals, a switching transistor, an inductance, a discharge diode, a capacitor forming with inductance and inductance-capacitance filter of angle-shaped type, the resistive output voltage sensor, the unit of comparison of sensor voltage with voltage of the unit of reference voltage and the switching transistor control unit is also fitted with the unit of change of the current direction in a load. The unit is designed with a possibility of change of the current direction in a load.
EFFECT: expansion of functionality of the device at its implementation, obtaining output voltage with randomly pre-set periodic and continuous form, in particular, sinusoidal, with keeping of properties of simplicity of circuits of its implementation and rigid load characteristic.
SUBSTANCE: device contains a traction-feeding transformer with three secondary winding sections, a rectifying and inverting converter with eight arm of series connected thyristor and a diode forming a bridge circuit, a load comprising series connected and engine and an inductive resistance, a zero thyristor connected parallel to the load and connected with it zero thyristor control unit connected to the first section of the secondary winding of the transformer and containing mutually connected the voltage sensor, the rectifier, the shaper of clock pulses, the time-pulse generator, the comparator, the univibrator, the traction-recuperation mode switch and "AND" element.
EFFECT: decrease of the engine power consumption due to increase of average value of the rectified voltage at the output of the rectifying and inverting converter due to forming in the traction mode in each zone of adjustment of zero values of the rectified voltage during the time.
SUBSTANCE: device contains the first electric bridge of three parallel connected half-bridges formed by several series connected transistors, shunted by free-wheeling diodes, the second six-arm electric bridge formed by three parallel connected half-bridges, made from two series connected pairs of transistors, each of which consists of two transistors connected by heteronymic power leads, and the voltage divider formed by three series connected condensers. The first and the fourth outputs of the voltage divider are connected to inputs of the first electric bridge, and its second and third outputs - to inputs of the second electric bridge. Outputs of homonymous half-bridges of the first and the second bridges are connected among themselves and connected to the respective phase of the engine.
EFFECT: development of self-excited voltage inverter allowing to reduce power losses due to providing the minimum resistance of the circuit through which the current of each phase flows, with keeping of low level of the highest voltage harmonicas on engine phases.
SUBSTANCE: invention is attributed to the field of electric engineering and can be used for control of conversion circuits. The conversion circuit comprises at least two phase modules (4), each of them including the first and second partial conversion systems (1, 2). In each phase module (4) partial conversion systems (1, 2) are interconnected in series. Each partial conversion system (1, 2) comprises several in-series double-pole switch cells (3). The method for control of the conversion circuit includes generation of control signals (S1, S2) for switching cells (3) additionally out of an antihunt (Vd, U1, Vd, U2), which is shaped out of measured current (11, i2) though the respective partial conversion system (1, 2) and preset value of resistance (Rd).
EFFECT: damping of undesirable currents in conversion systems.
8 cl, 6 dwg
FIELD: the invention refers to the sources of electric supply of electron aids whose functioning is carried out on the principles of electronic engineering and/or radio technique.
SUBSTANCE: the aids include at least one active element with three or more electrodes particularly a transistor and using this active element(elements) carry out amplification, conversion or generation (formation) of working electric signals of alternating or direct voltage including broadband signals. The mode and the arrangement for electric supply of predominantly portable electron aids is carried out by way of using at least one a three-electrode active element, amplification, conversion or generation of an electric signal of alternating or direct voltage based on supplying voltage on the clamps of the electron aid, impulse voltage whose on-off time ratio is within the limits of 1,1-20,0 is used as supply voltage. In the second variant of the mode and of the arrangement the impulse voltage has the following parameters: the frequency of impulses is at least one level higher than the maximum frequency of the spectrum of the electric signal of alternating voltage or at least one level less than the minimal frequency of the spectrum of this electric signal, and the duration of the impulse fronts is at least one level less than the magnitude inverse to the maximum frequency of the spectrum of the electric signal of alternative voltage.
EFFECT: decreases electric consumption.
10 cl, 3 dwg
FIELD: transformation equipment engineering, possible use for engineering indicators of three-phased voltage.
SUBSTANCE: device contains three-phased bridge rectifier, made on diodes (1-6). Output contacts of rectifier, being output contacts of indicator, are meant for connecting load circuit (7). Resistors (8-10) are introduced into input circuits of alternating current, connected to corresponding phases of voltage supply being measured. Resistance value of each resistor (8-10) equals to (0,5÷0,7) of value of active resistance of constant current load chain (7).
EFFECT: increased precision of measurements due to improved dynamic characteristics of measuring device.
FIELD: transformation equipment engineering, possible use for controlling reverse thyristor transformer of constant current or thyristor voltage regulator, for example, to ensure smooth launch of asynchronous electric motors.
SUBSTANCE: device contains control signal source (input of phase-shifting device), adder, amplitude modulator, integrator, 2 relay elements, logical element "XOR", three logical elements "2AND", subtracting "n"-bit binary counter, input for connecting a supply of supporting voltage, generator of stable frequency impulses, adding "n"-bit binary counter, digital comparator, logical element "kAND", where n>k, mono-stable multi-vibrator, logical element "2OR", input for connecting the source of control impulses for power thyristors. Device belongs to the class of integrating systems with two digital scanning functions. One scan is independent and is generated due to generator of stable frequency impulses. The second scan is dependent, which is generated from control signal, and transformed due to impulse signal from output of voltage transformer to impulse frequency. Command for managing power thyristors is generated at the time moments when numeric values of independent and dependent scanning functions are equal or exceeded.
EFFECT: increased interference resistance, increased precision.
FIELD: power electronics, possible use in powerful supplies of stabilized current.
SUBSTANCE: the device contains two-cycle impulse transformer with two high frequency controllable switches (1,2), an input LC-filter (3) and output transformer (9), connected to secondary winding (8) of which are: rectifier (7); network rectifier (10), connected through switch (11) to input of LC-filter (3); output LC-filter (4), is connected by input to output of rectifier (7) and by output to load circuit (5); control unit (15) is connected by output to contacts of primary windings of dividing transformers (17,18), contacts of secondary windings of which are connected to control circuits of switch (1,2); adding amplifier (16) is connected by first input through current sensor (6) to output of LC-filter (4) and by output to input of control unit (15); pulse-width modulation comparator (12) is connected by output to control input of switch (11) and by first input through generator of linearly changing voltage (13) is connected to output of clock impulse generator (14); integration adder (21) is connected by first input to current setting supporting voltage supply (19), by second input to output of current sensor (6) and by output to second input of adding amplifier (16); and amplifier with piecewise-linear transfer characteristic (20) is connected by input to output of adding amplifier (16) and by output to second input of the pulse width modulation comparator.
EFFECT: increased reliability of operation of impulse transformer and precision of regulation of its output current for any value of current setting signal.
FIELD: electric engineering.
SUBSTANCE: in accordance to the invention, a transformer is coupled into alternating current diagonal of semi-bridge thyristor inverter. Secondary winding of transformer through diode bridge is connected to constant current load. In parallel to main semi-bridge thyristor inverter, an additional semi-bridge thyristor inverter is included into constant current diagonal which has capacitors with approximately ten times less capacity compared to the main one. An additional transformer winding is incorporated into alternating current diagonal of additional inverter with number of coils less than that of its primary winding. The inverter is controlled from typical pulse-width regulation circuit in broad range of loads.
EFFECT: prevention of additional power losses in commutation block, ensured constancy of power amplitude on load during regulation and simplification.
FIELD: electrical engineering.
SUBSTANCE: invention relates to electrical engineering and may be used to control the electric train AC. The invention increases the accuracy in control of the converter and eliminates alarm operating conditions. The method of control of tetrasquare converter with computation of switching phases includes generating the data on the dependency of the gate switching intervals on the depth of modulation and inputting this data into the memory of the converter control system for the range of tolerable operating frequencies in compliance with the number of the PWM-intervals. The control system is used to preset the current voltage value at the converter output, the current circuit value and the value of phase difference between the circuit voltage and current. The circuit current value id regulated by varying the voltage modulation at the converter input. The intervals of the controlled gates switching are calculated and the voltage modulation value is varied by setting the control signal for cutting in- cutting off the gates. The method features the correction of the gates cutting in interval values allowing for certified data on controlled gates, operating conditions and the converter load nature. Here, in every half-cycle of the supply voltage, the maximum modulation frequency is limited by the gate switching duration. The microprocessor device to control the said converter incorporates a timer, a processor, an operating memory, a permanent memory, ANC, drivers' unit, current sender, synchroniser and the input current amplitude generator, timer inputs-outputs, those of the processor, permanent memory, operating memory. The drivers' unit inputs are coupled by the data-address bus. It also includes the converter operation parameters generator, voltage sender, gate switching phase computation unit, the unit of limiting switching intervals, the time interval I/O unit, the unit of communication with the converter load.
EFFECT: higher accuracy of control over converter, ruling our abnormal operating conditions.
2 cl, 3 dwg
SUBSTANCE: invention refers to electric engineering and may be used in inductive heating systems with semi-conducting frequency converters when control system are designed. Method is intended for controlling output voltage of converter containing several inverters and multi-elements matching transformer with primary windings being connected to proper inverters and secondary windings being connected serially forming voltage summation circuit. Output voltage of one inverter is controlled by means of DC voltage converter connected to inverter input within the range defined by low and high thresholds. Other non-controlled inverters connected in parallel or fed from rectifiers are actuated into one of two states: "boosting voltage" or "short circuit". Output voltages of non-controlled inverters are set to be proportional to weight coefficient of bit pattern (1, 2, 4, 8, 16, ...). Different combinations of non-controlled inverters states form several levels of output voltage further creating several sub-ranges (zones) of output voltage controlling. Control is conducted by controlled inverter within those sub-ranges. Therefore, if output voltage of controlled inverter achieves proper range of controlling, states of non-controlled inverters are changed so that sum of non-controlled inverters weight coefficients being in "voltage boosting" mode could change by one. It results in control range shifting in controlled inverter by the voltage value assigned for lowest weight coefficient.
EFFECT: increase of energy indicators for conversion, creation of favourable switching conditions for converter transistors and increase of conversion power coefficient; improvement of energy indicators for conversion and provision of favourable switching modes for converter transistors.
FIELD: electrical engineering.
SUBSTANCE: invention pertains to electrical engineering, and specifically to invertors for autonomous electrical power supply for different electrical equipment, requiring use of sinusoidal alternating current. The direct current converter has a generator of sinusoidal voltage, a driver-amplifier and a power electronic converter. The sinusoidal voltage generator with frequency f is in the form of a miniature motor-generator, the electric motor of which rotates with a stable velocity proportional to frequency f and the motor-generator controls the electronic breaker-splitter. The electric motor of the motor-generator works on direct or alternating current and can smoothly change speed of rotation.
EFFECT: obtaining an output voltage without distortions, comparable to a perfect sinusoid, increased reliability of operating in external electrical fields, wider range of applications and reduced costs of manufacturing.
5 cl, 4 dwg
SUBSTANCE: composition of the electric drive of an alternating current includes the frequency converter, the invention can be used for the launching and control of the work of asynchronous or synchronous electric drives with the working voltage 6...10 kV and power of up to tens of mW. The high-voltage electric drive of the alternating current with the three-phase electric motor contains a source of an adjustable direct current, three-phase bridge thyristor chopper, switching devices connected to the outputs of alternating current of the inverter consistently with the phases of the three-phase winding of the electric motor, sensors of current and voltage and the control devices of the inverter and switching devices. Each switching device contains a capacitor with two outputs and the bidirectional symmetric operated semi-conductor key connected in parallel to it completely. Starting of the switching device in the electric drive is carried out in the manner as it specified in the materials of application for each of the three variants. In the electric drive for each of the variants protection of semi-conductor keys is provided at extraordinary and emergency situations.
EFFECT: reduction in the cost; increase of technical and economic parameters and reduction of expenses for the current operational service of the electric drive.
3 cl, 21 dwg
FIELD: electrical engineering.
SUBSTANCE: invention relates to remote transfer and conversion of super-high-frequency energy into DC electrical power. The proposed method consists in fitting an aluminium foil enclosure on over the entire surface of the vehicle airframe skin. The super-high-frequency converter is made in a material representing a mix of two chemical solid-state components with grain size not over 30 to 50 microns, taken in equal proportion but different atomic numbers, and forming, when combined, a dipole solid-state matrix. Note that the said bi-component mix is applied uniformly onto the said skin enclosure, the like poles of the dipole matrix being combined and connected to appropriate terminals of the vehicle flight control components.
EFFECT: higher efficiency power supply.