High-voltage frequency-controlled electric drive. RU patent 2505918.
 Regulator of three phase current / 2500063Regulator of three-phase current comprises three branches with a respective input (U1, V1, W1) and output (U2, V2, W2), with five pairs (1, 2, 3, 4, 5) of connected antiparallel valves for reversing the magnetic field. The first input (U1) via the first pair (1) is connected to the first output (U2), the second input (V1) via the second pair (2) is connected to the second output (V2) and via third pair (3) to the third output (W2), and the third input (W1) via the fourth pair (4) is connected to the second output (V2) and via the fifth pair (5) with the third output (W2). As a damping circuit, to each input (U1, V1, W1) and each output (U2, V2, W2) there is a resistive-capacitive half-link connected so that one end of the respective resistive-capacitive half-link is connected to a corresponding input (U1, V1, W1), accordingly, with the output (U2, V2, W2), and so that the second ends of these resistive-capacitive half-links are connected with the help of a cross connection (Q). |
 Highly dynamic sensorless asynchronous drive with direct control of torque / 2498497Device consists of the power unit which includes series-connected rectifier of the mains voltage, ripple filter with voltage sensor, voltage inverter and electric motor which windings are connected through block of phase current sensors to output of voltage inverter; the unit also includes setter of the actual motor angle speed, speed regulator and setter of the motor flux linkage, block monitoring status of the motor, summators, coordinate voltage converter and divider; according to the claimed solution there's also calculator of voltage vector projections, shaper of voltage vector projections and vector modulator. |
 Energy-saving system for control of asynchronous drive / 2498496Energy-saving system for control of asynchronous drive contains a block for input of preset rotary speed of asynchronous motor, voltage regulator, block of drivers, autonomous voltage inverter, calculator of stator current vector projections, calculator of stator active current, multipliers, matching amplifier, filter, integrator, calculators of sine and cosine angle of voltage vector turn, block for switching of drive operation modes, block of pulse-length modulation and current sensor interconnected in the way specified in the application. At that signal outputs of current sensors are connected to outputs of calculator of stator current vector projections which is by its outputs is connected to the first and third input of calculator of stator active current, while the second and fourth outputs of calculator of stator active current are connected to outputs of multipliers. |
 Multizone reversible converter and method of its control / 2498490Multizone AC reversible converter contains parallel key bridges, transformer with one or more secondary windings, diode leg that forms circuit of full-wave rectifier bridge with potential zone-phase regulation which is connected to commutator motor, current sensor of the primary network and voltage sensor of the primary network connected to control system. Each key-controlled leg consists of series-connected diode and controlled electronic switch and for this purpose IGBT transistor (module) can be used. In case of zone-phase control of reversing converter after the moment of voltage transfer through zero at first voltage from fine winding is supplied by means of key-controlled legs to electric motor; then after while additional voltage is supplied from auxiliary winding of transformer and after while this voltage supply is stopped. Time of auxiliary winding of transformer on and off is selected do that line current shift in regard to the mains voltage at the first harmonic of the mains frequency is reduced up to zero. |
 Frequency converter and voltage stabiliser for uninterrupted power supply / 2498487In frequency converter and voltage stabiliser for uninterrupted power supply (UPS) an output signal is controlled in converter of one or more UPSs. Distortion stipulated at least partially by ripple voltage can be eliminated from control signal that controls entry of input current to the converter. Systems and methods described in materials of the present application provide a simple and effective method for reduction or elimination of one or more subharmonic oscillations or total harmonic distortion from input current of the converter during synchronous and asynchronous operation modes. The converter can include one or more rectifiers and inverters. |
 Control method of frequency-assisted electric drive / 2496219According to control method of frequency-boosted electric drive in closed positions of commutators (1, 5) and disconnected commutator (7) as per signals of controller (9) there performed is engine acceleration to the frequency close to frequency of network 8. During acceleration, converter gradually increases output frequency starting from zero one. Upon completion of acceleration process of motor 6, converter 2, as a rule, is synchronised with network 6. After that, controller 9 supplies command for closure of network switch 7 and pickup of control pulses (locking) by inverter (4). When this command is being implemented, almost immediate locking of converter takes place and contacts (7) are closed just in a few milliseconds. On the motor side, converter with closed transistors represents a diode bridge, to the poles of which a capacitor is connected. Therefore, it serves as a damping chain at connection of contacts (7). Such a chain reduces possible overvoltages and vibrations occurring at connection due to non-homogeneity of closure of contacts, their rebound, disturbance of phase synchronism at synchronisation, etc. |
 Controller for load start-up system / 2496218Controller for load start-up system, which includes converter for changing output voltage of direct current power supply source, inverter for conversion of direct current voltage supplied from converter to three-phase alternating current voltage that is supplied to load, and smoothing capacitor connected parallel between converter and inverter, includes controller of inverter for pulse-width modulation (PWM) control of inverter with two-phase modulation and controller of converter for PWM control of converter. Frequencies of carrier signal of inverter, which is used in controller of inverter, and carrier signal of converter, which is used in controller of converter, are the same. And when the point of time, to which input electric current to inverter is generated, which corresponds to carrier signal of inverter, is diverted for the specified period of time, phase difference between carrier signal of inverter and carrier signal of converter is offset by the value equal to the specified period. |
 Electric machine and vehicle power system / 2494524Electric machine comprises a vessel, where stator windings are installed in close proximity to the rotor. There is also a circuit comprising transistors and diodes and connected to the specified windings. A switching circuit is included into a current inverter, which also comprises a pair of inductors installed on power supply buses, and switching capacitors. The current inverter as well as the windings is inside the vessel. A vehicle power system comprises a source of continuous power connected to electric machines by means of integrated electric drives. Each of electric drives comprises at least three windings installed in close proximity to rotors of engines associated with these electric drives. The switching circuit of the accumulating circuit electrically connected to each winding is in closed condition for rotation of the rotors or in opened condition for supply of energy into a local power accumulator. |
 Linear asynchronous electric drive / 2494522Linear asynchronous electric drive comprises an inductor 1, comprising a core, on teeth 2 of which there are winding coils 3, and an electroconductive anchor 4. In each upper part of teeth there are two screening turns 5, outputs of which are connected to contacts of sealed-contact relays 6, coils of which are connected with a switching device. The switching device provides for the possibility of simultaneous closure of at least four screening turns, placed on four adjacent teeth of the inductor, which form the initial row. In first two teeth the turns that screen their right parts are closed, and in the third and fourth teeth the turns are closed, which screen their left parts. To start a pitch of the electroconductive anchor, the switching device opens a turn that screens the left part of the fourth tooth, and to complete the pitch - it opens a turn that screens the right part of the first tooth, closes turns that screen the right parts of the second and third teeth, and a turn screening the left part of the fifth tooth. To fix the electroconductive anchor, after the pitch the switching device opens turns that screen the third and the fourth teeth, and disconnects winding coils arranged on these teeth from the source of voltage. |
 Electric drive of reciprocating action for impulse vibration source / 2491709Electric drive is made as a non-linear electromagnetic motor with body made of sections mounted at diamagnetic pin guide; out of these two joining sections that contain power windings one section is connected to the support while the other one is connected to intermediate sections equipped with pin position proximity sensors; at that the diamagnetic pin guide is fixed in an intermediate section of the body connected to the section of a holding electromagnet made as a sucking coil with poles. |
 Control method of parallel connected modules of uninterrupted power source / 2502181Control method involves use of similar modules switched in control chains either to a drive or driven module modes; besides, in the drive module there used is additional feedback as to current of capacitors of output filters of modules. In case of failure of any of the modules, it is disconnected from load and the primary power network, and an operating mode of each module, if required, is changed by means of switches. In order to change over the driven module to the drive module operation, a signal is supplied to its input, which is obtained by switching an input chain from the setting signal of current to sine-shaped voltage signal, from which the connected signal of the main feedback as to voltage and total current signal of capacitors of output filters of modules is deducted. At the same time, a current signal of the drive module is connected to a common control bus of output current of the drive module. When an additional module is being introduced to an uninterrupted power source, first, it is set to a drive module mode, and then it is switched over to a driven module mode. |
 Method of frequency converter control / 2482595In the method of frequency converter control with width-pulse modulation the moments of generation of frequency converter power key control signals are additionally changed at each switching interval in accordance with a random law, leaving the average number of switching intervals at each period of output voltage as permanent. Changing the moments of generation of frequency converter power key control signals is carried out by means of additional modulation in accordance with a random law (on each switching interval) of speed of reference saw-toothed high-frequency voltage or low-frequency control voltage growth. As a result the high-frequency spectrum of output voltage of the frequency converter is smeared, i.e. spectral components of combination harmonics are broken. Amplitudes of separate high-frequency harmonics are reduced, and the harmonic spectrum of the output voltage of the inverter is smeared simultaneously with reduction of specific energy of discrete frequencies. |
 Method of asynchronous control for four-quadrant converter / 2450412Method of asynchronous control for four-quadrant converter is implemented by asynchronous sine pulse-width modulation with shift of clock and modulating signals in reference to main voltage phase. Switching of converter power keys is made at instant of time determined by ratio of modulation voltage and sweep voltage of sawtooth voltage generator on the basis of logic functions. Control pulses are generated by means of clock signal comparison with pre-set modulating sine signal variable in frequency and amplitude: sign of modulating signal is changed to the opposite one twice for instants of time corresponding to points of output voltage natural commutation. In compared channel high level of pulse-width modulated signal is generated if clock signal is less than pre-set signal or low level of pulse-width modulated signal is generated if clock signal is more than pre-set signal. In output channel two coupled output control signals are generated with inversion to each other from the first and second converter arms and simultaneously with commutation of modulating signals output signals are inverted in reference to pulse-width modulated signals in compared channel. Sawtooth signal is used as a clock signal. While generating control signals for converter keys clock signal is shifted in phase in reference to mains voltage transition through zero. Value of clock signal angle of shift is equal to value of modulating signal phase. Thus, phase shift of modulating signal in reference to mains voltage is asynchronous in regulation process. |
 Non-transformer frequency converter for controlled medium voltage electric drive / 2414043Non-transformer frequency converter for controlled electric drive for networks with insulated neutral of class 6, 10 kV and more includes rectifier, three-phase voltage inverter with control unit of width modulation, capacitor connected to the direct current link of inverter, output LC filter, sensor of phase-to-phase voltages and control of phase-to-phase voltages, capacitor bank of LC filter, which is divided into two unequal parts. The main part (95% of total capacity or more) consists of capacitors connected between output phases of inverter and ungrounded. Small part is connected to output phases of inverter as per star circuit the neutral of which is grounded; to direct current link of inverter there connected are two magnetically connected windings arranged on common ferromagnetic core. Outputs of the above windings are connected so that when operating current of frequency converter flows via windings, magnetomotive forces of windings are opposite directed. To non-transformer frequency converter there introduced is voltage sensor of the above small part of capacitor bank of LC filter, damping neutral displacement control and adder, which are connected as it is specified in the request materials. |
 Inverter generator and method of its control / 2406216Inverter generator comprises dynamoelectric generator unit that includes generator unit, converter (20) to convert variable current into constant current, inverter to convert constant current into variable current furnished with gate elements to supply electric load, inverter control device to control gate elements by PWM-signal generated using reference sine signal with wave shape of required output voltage and carrier signal in every control cycle (step) defined by carrier frequency. It generates preset frequency variable current. Inverter control device varies carrier frequency in compliance with inclination (designated, for example as D 1, 2) of reference sine signal, and, in particular reduces carrier frequency with reduction of reference sine signal inclination. |
 Method of direct to quasisinusoidal voltage conversion with vector pulse-width modulation / 2402867Conversion method consists in logical conversion of the result of comparison of the carrier saw-tooth signal with trigger level signals. Every time the preset voltage vector angle reaches a value divisible by π/n, where n - an integer 1 or 3 the saw-tooth signal is reset to the initial condition which is pre-defined and located within the range from 0 to the saw amplitude maximum. |
 Control method of four-quadrant converter with shaping of modulating signal / 2396690In control method of four-quadrant converter with shaping of modulating signal the current flowing through the throttle is controlled by changing the duration of time of application thereto of voltage of alternating voltage source and voltage difference of alternating voltage source and capacity of inlet filter, which are determined by the ratio of modulating sinusoidal signal and clock triangular signal, which are shifted relative to voltage of alternating voltage source through angle where X- inductive resistance of current circuit of throttle at application thereto of voltage of alternating voltage source; I - actual throttle current value; U - actual voltage value of alternating voltage source. Half-period of supply voltage is split into m equal i-x sections equal as to duration of clock period of pulse-width modulation of voltage, where i=1…m. Actual current value of the network for each of the sections is measured. At each half-period there determined is mismatching of actual current values Ii and Im-i+1 by the formula ΔIi=Ii-Im-i+1. The obtained mismatch value is multiplied by integral coefficient obtained from the output of proportional-integral voltage control. In the sections the ordinal number of which is less than m/2, there subtracted is the obtained mismatch value from the specified value of current supplied from proportional-integral voltage control on filter capacitor. In the sections the ordinal number of which is more than m/2, the obtained mismatch value is added to the specified value of current supplied from proportional integral voltage control on filter capacitor. At the next half-period which is similar as to the sign, there formed is modulating function Fm by adding current values obtained in each section separately. |
 Method of width-pulse signals formation for control of autonomous inverter / 2389128In method of width-pulse modulation based on comparison of one reference signal and three modulating sinusoid signals with simultaneous change of sign in modulating signals and variation of logical level of output control signals six times in a period in points that correspond to natural switching of output voltages, signal of serrated shape is used as a reference. At the same time in the first range of motor speed control frequency of reference signal is invariable. In the second range of speed control after changeover to mode of modulator saturation, specified frequency is formed to maintain permanent ratio of frequencies between reference and modulating signals. |
 Method to control three-phase bridge converter / 2379819Invention relates to electrical engineering and can be used to control power converters. Converter circuit comprises unit (1) of scaling setting current signals to current of converter DC side, DC power source (7) and set of six power keys connected in bridge circuit, circuit (2) to directly convert coordinates, unit (3) to calculate sector number, unit (4) to calculate reference signals and unit (5) of pulse-width modulation (WPM). WPM outputs and output of unit (3) make inputs of generator of control pulses for converter keys (6). Proposed control method consists in that currents are generated on converter AC side by forming two adjacent active current vectors and one zero vector in WPM period. Closed state of keys on one of the arms in bridge converter corresponds to every zero vector depending upon sector number. Proceeding from the analysis of preset phase current signal sings scaled to current on converter SC side, sector number is determined whereat preset phase current vector in current time interval is located. Phase current signals are converted from three-phase coordinate system a, b, c into stationary orthogonal system of α, β-coordinates, and, from obtained preset current projections on axes α and β,current vector lengths are calculated along directions of two active base vectors of the sector. |
 Method of width-pulse signals formation for control of autonomous inverter / 2326486Invention is intended for control of autonomous inverters with width-pulse modulation of output voltages and may be used for frequency regulation of induction motor speed. Technical result consists in increase of output voltage quality and as a result expansion of regulation range and reduction of losses in the motor. Specified technical result is achieved by the following: in the known method of centered width-pulse modulation, which is based on comparison of support signal of triangular shape and three modulating sinusoidal signals, additionally simultaneous change of modulating signals type is performed six times per period in points that correspond to natural commutation of output voltages, and logical level of output control signals. |
 Five-phase phase changer / 2503121Invention may be used to create rectifiers for controlled electric DC and AC drives for machines to increase their efficiency, and also on transformation substations for power supply to electrified railway roads, in electric metallurgical and chemical industry to reduce the value of pulsations of rectified voltage and to reduce content of higher harmonic components in an AC curve in a three-phase grid. The proposed five-phase phase changer comprises a three-phase transformer, having three coils of the primary winding, which are connected as a star network, and are connected to the three-phase grid with a zero wire "0", six joined main coils of the secondary windings, one additional coil of secondary winding and taps from turns of the main coils of the secondary windings, which jointly with the output clamp of the additional coil of the secondary winding create a symmetrical five-phase system of voltages. Each main coil of the secondary winding of the transformer is a side of a "hexagon" A, B, C, D, E, F, transforming a symmetrical three-phase system of voltages into a symmetrical six-phase system of voltages, at the same time the additional coil of the secondary winding with its beginning is connected to the unit of the "hexagon" circuit, which is not connected with the main coils of the secondary winding of the phase, on the rod of which there is the additional coil of the secondary winding. |
FIELD: electricity.
SUBSTANCE: in the high-voltage frequency-controlled electric drive, an uncontrolled high frequency converter is connected through a multiple-winding single-phase high-frequency transformer to a controlled high frequency converter having a cellular type, wherein inputs of rectifier-inverter cells are connected to corresponding secondary windings of the single-phase high-frequency multiple-winding transformer, the primary winding of which is connected to the output of the uncontrolled high frequency converter, and the input of the latter is connected through a reactor to the mains supply.
EFFECT: reduced weight and size.
2 cl, 5 dwg
The invention relates to the electrical engineering, in particular to the areas of automated electric drive and converting equipment and is designed for speed control of asynchronous and synchronous AC motors.
Known high-voltage variable frequency drives (hereinafter VFD), for a voltage 3-10 kV, type ACS5000 ABB (N. Donskaya, A. Ivanov, V. Mathison, I. Ushakov «Multilevel standalone inverters for electric drive and electric power industry», magazine «Power electronics», 2008, №1, Fig. 1 on page 44), made on the basis of multilevel inverters and frequency converters (hereinafter FC). In the composition of the VFD is a complex multi-winding transformer, working from the industrial network with frequency 50 Hz and adjustable frequency Converter, which can run on different schemes, such as a bridge or . When the capacity of over 1 MW cost transformer makes about 50% from the cost of the drive.
Disadvantages analog - increased weight and cost indexes of the VFD.
Also known high-voltage frequency-regulated drive with a multi-FC like ABS-DRIVE (NV Donskoy, A.G. Ivanov, V.A. Mathison, A.I. Ushakov «Frequency-adjustable high-voltage electric drives» // news of the Academy of electrotechnical Sciences of Russian Federation, Moscow, 2010. №1, p.23-25).
Similar (see figure 1, where the simplified scheme) includes a motor 6 and power module 1, consisting of interconnected transformer 2. with secondary windings 3, adjustable frequency Converter type 4 control system 5. Change the frequency and voltage output power module 1 adjustable speed motor 6. Control system 5 performed on the basis of the controller, and multi-winding transformer is connected to the industrial network is 6 kV, 50 Hz.
The disadvantage of analog, are of large size, weight, complexity and high cost of the three-phase transformer 2.
The closest to the technical essence of the claimed solution, and taken as a prototype, is a device for motor control (recommended expertise FIPS in the materials request from 07.12.12,) (useful model Certificate EN 34295 U 1, 02 6/00, 27.11. 2003).
This device contains a step-up high-frequency transformer connected to the industrial network of 380 V, 50 Hz through unregulated high frequency Converter, the output transformer is connected with the electric motor through the rectifier and inverter forming adjustable frequency Converter. In describing the prototype of the function chart of the specified device. Change of frequency and voltage at the output of the adjustable frequency Converter governed by the speed of the motor. Through the use of unregulated high frequency Converter and enhances the high-frequency transformer solved the task of reducing the weight and size of the transformer.
Disadvantages prototype:
1. In our opinion, the prototype practically not functional due to the connection of the Converter of high frequency to a network without the reactor (or equivalent transformer), which should include: limitation of fault currents. and the derivative of the current through the diode (at their switching) rectifier installed at the input of the frequency Converter and to limit the surge of current in this rectifier encountered when dealing with mandatory capacitance filter at the output (see, for example, Zinoviev G.S. Fundamentals of power electronics. Izd-vo NSTU, 2003, .664).
2. In the prototype is solved in a simpler task management engine from the frequency Converter, consisting of a simple (bipolar output) rectifier, the output of which is connected to the same (bipolar electric input) inverter. For more complex high-voltage systems are multi-level adjustable frequency converters (as in the analogue)specified rectifier and inverter are not suitable. They inverter must also be multi-level, for example, , connecting to a more complex rectifier unit.
The technical result of the proposed solutions - reducing of mass and size parameters of frequency-regulated electric drive.
The technical result is achieved by a high-voltage frequency-regulated electric drive, containing respectively interconnected electric motor, unregulated high frequency Converter and power module, consisting of high-frequency transformer and adjustable frequency Converter control system, unregulated high frequency Converter via multi-winding single-phase high-frequency transformer is connected with adjustable Converter of high frequency, made type, in which the inputs rectifier-inverter cells consisting of single-phase rectifier blocks with capacitive filters and inverter units, connected to the secondary windings of the single-phase high-frequency transformer, the primary winding of which is connected with the release of unregulated Converter high frequency, and input of the latter entered through the reactor is connected to the mains.
Performed by the FCD on more power to the rectifier-inverter cells each phase electric motor connected respectively United corresponding power unregulated high frequency Converter is connected through the corresponding reactor to the mains, and single-phase multi-winding transformer power module.
Through the implementation of an adjustable frequency Converter type and connecting input unregulated high frequency Converter to the industrial network through the reactor, as well as the original scheme of connection of the constituent elements of the device, reduced mass and dimensions parameters of high-voltage frequency-regulated drives.
Implementation of frequency-controlled electric drive of the big capacity with the formation of three blocks to power each of the three phases of the motor from the individual block of the power produced on the basis of unregulated high frequency Converter and power module.
The essence of the proposed that the alleged invention is illustrated by drawings.
1 shows a diagram of a prototype,
figure 2 illustrates the functional diagram of the device,
figure 3 shows a scheme with regard to high-frequency VFD type with non-regulated single-phase inverter high-frequency and phase-frequency transformer,
figure 4 - the cell circuit adjustable frequency Converter,
figure 5 shows the wiring for a VFD power units (this scheme is suitable for VFD high power).
The following conventions are taken:
1 - power module;,
2 - multi-winding transformer;
3 - secondary winding transformer;
4 - adjustable frequency Converter;
5 - control system;
6 - pH AC motor;
7 - uncontrolled high frequency Converter;
8 - rectifier unit;
9 - capacitor filter;
10 - voltage inverter;
11-reactor (three-phase or three-phase);
12 - rectifier-inverter cell;
13 - current sensor;
14 - rectifying block in cell 12;
15 - filter capacitor in cell 12;
16 - inverter block in cell 12, consisting of keys, for example, transistor with reverse diodes;
17 - a power block that contains the unregulated high frequency Converter 7, for example, at 1000 Hz and high frequency corresponding multi-winding transformer 2 1 energy module.
Parameters:
f 1 - output frequency 7, f 2 - output frequency 4;
U - voltage output 4 in figure 2 and figure 3;
Uy - voltage control input 5;
i - signal current sensor 13. The claimed device includes a power module 1, which includes a transformer 2 with secondary windings 3, adjustable frequency Converter 4, made type, the control system 5, and motor 6 respectively interconnected. Multi-winding transformer 2 is the single-phase high-frequency, and its primary winding is connected to unregulated high frequency Converter 7, consisting of a rectifier unit 8, filter capacitor 9 and voltage inverter 10, input unregulated high frequency Converter 7 is connected to an industrial network, for example, through a three phase reactor 11.
In VFD type of secondary windings 3 single-phase transformer 2 are connected with rectifier-inverter-controlled cells 12 included consistently with the appropriate sensors current 13 in the appropriate phase motor 6. Each cell contains 12 rectifier unit 14, filter capacitor 15 and inverter block 16, consisting of keys, for example, transistor with back diodes. Unregulated high frequency Converter 7 and high frequency multi-winding transformer 2 in VFD great power form a power block 17, number of data blocks equal to the number of phases 6.
Unregulated high frequency Converter 7 may contain power factor corrector, designed to improve electric drive power and with high frequency transformer 2 can be executed respectively in single-phase or three-phase version.
Each rectifier-inverter cell 12 adjustable frequency Converter 4 is made by circuit. Can be performed from the zero point of the relevant secondary winding transformer 2.
The proposed device provides the drastic reduction of weight and size of the high-frequency transformer 2, as well as the number of diodes, rectifier blocks 14 rectifier-inverter 12 cells, which improves weight and cost indexes of the electric drive as a whole.
The claimed device works as follows.
Power module 1 is supplied with voltage via multi-winding transformer 2, made from high-frequency unregulated high frequency Converter 7. This voltage is generated by rectification unit 8 mains voltage with frequency of 50 Hz and convert it to a voltage inverter 10 in high frequency, for example, 1000 Hz (voltage inverter 10 runs, for example, the relatively inexpensive thyristors).
I - the current phase of the reactor, e k [%] - voltage short-circuit. the reactor, which is comparable with the similar value for transformer 2 running a high-frequency (figure 1) and is, by about 5%.
It should be noted that at equal values of e (k =5% and current I (for the transformer and reactor), power transformer
S TP =3I·U
20 times higher than that of the reactor (where U - phase voltage network).
The voltage output from the inverter voltage 10 (2) arrives at a high frequency transformer 2, which is across the secondary winding 3 distributes it in the scheme of an adjustable frequency Converter 4. Adjustable frequency Converter 4 can be performed on different schemes and for motor speed control 6 produces a variable frequency, for example, f 2 =About - 50 Hz and DC voltage U from zero to 3 kV and 6 kV. The motor speed 6 changes in proportion to the specified frequency. Control system 5 provides an implementation of the requested algorithm of management by simultaneous changes in the frequency and voltage, for example, according to the law
.Due to the high frequency f1 dimensions and consumption of active materials transformer 2 running a high-frequency determined by the product of the number of turns W on the cross-section of the magnetic Q at a given his power, sharply reduced;
, whereB m - maximum operating induction in a magnetic core.
Multi-winding transformer 2, made a high frequency and a voltage inverter 10 can be run in single-phase or three-phase version. And adjustable frequency Converter 4 can be performed on the streets or schemes.
Figure 3 shows a diagram of high-voltage frequency-regulated drives with adjustable frequency inverter 4 type. Scheme of rectifier-inverter cell with 12 single-phase bridge rectifier 14 is shown in figure 4. To reduce the number of diodes in block 14 twice and reduction of power losses in them, this block in each rectifier-inverter cell can be performed also by a single-phase circuit with zero point corresponding to the secondary winding transformer. The circuit of the inverter voltage rectifier-inverter cell and its connection to filter capacitor and the output of the rectifier unit does not change.
Voltage at the motor 6 is formed by summing the output voltage rectifier-inverter cells 12 management by the given law. Otherwise, the principle of the operation of the scheme is similar to figure 2. It also uses one unregulated high frequency Converter 7. However, in VFD great power currents and unregulated power inverter high frequency 7 and transformer 2 increase. As a result of the practical implementation of unregulated high frequency Converter 7 and transformer 2 due to limited capacity of individual components, for example, keys voltage inverter 10, can be technically not optimal or unrealizable.
For systems VFD large capacity (figure 5 schematically shows the 17 power units of large capacity (for example, drive more than 5 MW), where instead of a single block of unregulated high frequency Converter 7 apply three blocks 7 and three high-frequency transformer 2 lower power, forming three power unit 17 (3 - number of phases ABC motor 6). Each block 17 provides power to all the rectifier-inverter cells 12 one of the phase adjustable frequency Converter 4. Such decision allows to optimize power multi-winding transformer 2 and unregulated high frequency Converter 7. Control system 5 (figure 2, figure 3) works in three signals - control, motor voltage and current sensors 13.
Thus, with the completion of the regulated Converter high frequency type, reduced overall dimensions of the drive. Multi-winding transformer and unregulated high frequency Converter form a power block. For systems VFD large power is used by several power units, and their number is equal to the number of phases. And in each of the power blocks unregulated Converter high-frequency and high-frequency multi-winding transformer are respectively less power.
1. High-voltage frequency-regulated electric drive containing interconnected electric motor, unregulated high frequency Converter and power module, consisting of high-frequency transformer and adjustable frequency Converter control system, wherein the unregulated Converter high frequency multi-winding through the single-phase high-frequency transformer is connected with Converter adjustable high frequency, made type, in which the inputs rectifier-inverter cells consisting of a single-phase rectifier blocks with capacitive filters and inverter units, connected to the secondary windings of the single-phase high-frequency transformer, the primary winding of which is connected with the release of unregulated Converter high frequency, and input of the latter entered through the reactor is connected to the mains.
2. High-voltage frequency-regulated electric drive according to claim 1, characterized in that in the performance at a greater capacity to every phase of a motor connected respectively United corresponding power unregulated high frequency Converter is connected through the corresponding reactor to the mains, and single-phase multi-winding transformer power module.