SU1427541A1 - A.c. electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in systems and mechanisms for general industrial use. The aim of the invention is to improve the performance of the work by increasing the high speed of roping and reducing electrical losses. The alternating current drive includes stator phase current regulators, null organs 20, 21, demodulators 18, 19, sawtooth voltage generator 22, and comparators 15, 16, 17. Consistently connected

Description

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1) Puller 13 and comparator 16 and controller 14 and comparator 17 are connected respectively between one of the transducer outputs 8 coordinates and one g of the inputs of the power amplifier 2. Connected to the stator winding of the synchronous motor 1. the outputs of the rotor position sensor 3, the transverse current component unit 7 of the stator current and the rotation regulator 12 |, the input connected by the rotor frequency sensor 4 to the rotation frequency of the rotor with the in-engine. The input of each Zero-organ 20,21 is connected to the corresponding output of sensor 3, and the code through one of the demodulators 18,19 - k1 to the second input of one of the comparator R | s 16,17, The second inputs of demodulators 1J8, 19 and the comparator 15, between the output of the current regulator 0 and

The exciter winding of the synchronous motor 1 by the exciter 9 is connected to the output of the generator 22. The regulator input 10 is connected to the output of the regulator 12. Each of the regulators 10,13,14 is stored by current feedback. Feedback signals to the specified controllers are received respectively from the sensors of the 5.6 stator phase currents and from the sensor 1 of the excitation current. The electric drive operates according to the subordinate control principle. The frequency control loop submits to the stator phase current control loops of the synchronous motor and its excitation current control circuit. In the drive, the rotor currents and the longitudinal component of the stator current are compensated for by instantaneous values, 1 Il.

.

The invention relates to electrical engineering, in particular, to an AC electric drive, which is based on a synchronous motor, and can be used in systems and industrial industrial applications with high demands on the accuracy and quality of speed control of the load.

The purpose of the invention is to improve the quality of the electric drive by increasing the speed and reducing electrical losses.

The drawing shows the functional diagram of the AC drive.

The AC drive contains a synchronous motor 1 with electromagnetic excitation connected to the output of the power amplifier 2, an angular position sensor 3 and a rotational speed sensor 4 mounted on the shaft of the synchronous motor 1j sensors 5 and 6 of the stator phase currents, block 7 of the transverse current component 7 stator, converter 8 coordinates, the reference inputs of which are connected to the outputs of the sensor 3 of the angular position, the pathogen 9j you connected

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by moving to the excitation winding of the synchronous motor 1, the regulator 10 of the excitation current, the first input of which is connected to the output of the current sensor I1, excitation, and the second input to the output of the speed regulator 12, under the key input to the output of the rotation frequency sensor 4

Regulators of 13 and 14 stator phase currents were added to the AC drive, comparators 15-17J, demodulators 18 and 19, zero-organs 2 (and 2, and sawtooth 22 generator connected to the output of one of the comparator 15 and output demodulators 18 and 19, the second inputs of which are connected to the outputs of the angular position sensor through the corresponding zero-organs 20 and 21. Therefore, the outputs of demodulators 18 and 19 are connected to the first inputs of the comparators 16 and 17, respectively.

The first inputs of the regulators 13 and 14 of the stator phase currents are connected to the corresponding outputs of the converter of 8 coordinates. The second inputs of the regulators 13 and 14 are connected respectively to the outputs of the sensors 5 and 6 of the stator phase currents, and the outputs specified

the regulators are connected respectively to the second inputs of the comparators 6 and 17, which are connected by outputs to the control inputs of power amplifier 2.

The output of the excitation current regulator 10 is connected to another input of the comparator 15 connected by an output to the control input of the exciter 9. You are running the unit 7 for setting the transverse stator current component connected to the first utravravl to the eight input of the coordinate converter 8, the second control input of which is connected to output of the speed regulator 12.

The synchronous motor 1 may be a conventional synchronous motor or a synchronous motor with electromagnetic reduction of the rotation frequency. The rotation speed sensor 4 can be a DC tachogenerator, the angle sensor 3 can be made on the basis of a selsyn, a rotary tran- sformer or an optical coding converter. The power amplifier 2 and the exciter 9 are transistor or thyristor pulse power converters. As a regulator 12 of the rotational speed, a PI controller can be used, implemented on an operational amplifier with an RC-chain in feedback. The task block is a voltage source. Comparators 15-17 are implemented in operational amplifiers. Demodulators 18 and 19 are implemented on operating amplifiers using analog switches. The zero-organ 20 and i 21 are implemented on semiconductor comparators, and the generator 22 sawtooth voltage is implemented on operational amplifiers.

The AC drive works as follows.

The rotational speed control circuit obeys two control loops for the stator phase currents i, i and the excitation current control loop iJi ij. The excitation current Lf of the motor is generated by the input signal of the speed controller 12. The stator current setting along the longitudinal axis d is also formed by the input signal of the regulator 12. In the electric drive, the dependences between the electromagnetic moment and the currents i, i | i, i of the motor are realized, ensuring flux linking constants H% const. This0

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The condition ensures the maximum speed of the electrical input.

Synchronous motor 1 causes the load to rotate. To obtain a given frequency of rotation in the regulator

12, a comparison of the signal Uj back to the output signal of the rotational speed sensor 4 is made. As a result, a control voltage is formed at the output of the regulator 12, which steps into the input of the converter 8 and the input of the excitation current regulator 10.

At the input of the regulator 10, a comparison is made between the setpoint and actual values of the drive currents. The error signal from the output of the regulator 10 in the form of a constant voltage is fed to the input of the comparator 15. To another input of the comparator. 15 receives a signal from the output of the 22 sawtooth voltage generator. On the comparator 15, the SHS is implemented. The signal from the output of the comparator 15 controls the driver's power keys 9,

A signal from the output of the speed regulator 12 (proportional to the stator current on the d axis) and from the output of the task block 7 (proportional to the stator current on the q axis) is fed to the input of the 8 coordinate converter. The signals from the angle sensor 3 also arrive at the reference inputs of the 8 coordinate converter. . At the output of the converter of 8 coordinates, sinugoidal tasks are formed at the input of the regulators 13 and 14 phase currents. From the outputs of the sensors 5 and 6 phase currents, the actual value of the phase currents flows to the other inputs of the regulators

13 and 14 phase currents, where a comparison is made between the specified and actual values of the phase currents,

Mismatch signals are fed to the inputs of the comparators 16 and 17, on which PWM is implemented. The other inputs of the comparators 16 and 17 receive signals from the sawtooth voltage generator 22 through demodulators 18 and 19 in phase or out of phase, depending on the angular position of the rotor shaft of the synchronous motor one,

The amplitude of the high-frequency component of the phase currents depends on whether the phase currents and the excitation current change in opposite directions or in accordance with the direction. Changing the phase of the PWM voltage depending on the angular distribution

The rotor can be achieved so that the instantaneous values of the phase currents and the excitation current are directed oppositely.

Due to this, the minimum loss of the electric drive is achieved as the amplitude of the high-frequency components of the phase currents decreases. You Comparator Signals 6 and 17 control the power switches in power amplitude 2 in such a way that the actual value of the phase currents coincides with the specified values of the currents. During the formation of phase currents, only the component d axis changes, compensating for the effect of changing the rotor current I of the motor I and ensuring the continuity of the flux linkage j (thus increasing the drive rotor power,; therefore, the introduction of electric AC drives of the regulators phase currents, comparators, ganas and a sawtooth generator, provides for mutual compensation of changes in the rotor current and the longitudinal component of the stator current according to their instantaneous values, thereby increasing speed and reduced electrical losses compared with the known device

Claims (1)

Invention Formula . An AC electric drive containing a synchronous motor with electromagnetic excitation, connected to the output of a power amplifier, a corner / ken sensor and a rotation frequency j mounted on a shaft of a synchronous motor, sensors of stator phase currents, a stator transistor component setting unit, a coordinate converter , the reference inputs of which are connected to the outputs of the angle position sensor, excite Editor I. Casard Compiled by A.Zhilin Tekred L. Oliynyk   6et ""% i9ip "- -t. (Mr aerKQEHnZ 4M" ce "l" Order 4863/54 Circulation 584 Subscription VNIIPY USSR State Committee for inventions and discovery 113035, MoscowJ Zh-35, Raushsk nab., 4/5 five 0 five 0 five 0 five A driver connected by an output to the excitation winding of a synchronous motor, a regulator of the excitation current, the first input of which is connected to the output of the excitation current sensor, and the second input - to the output of the frequency regulator connected to the output of the rotational speed sensor, which is , with a circuit for maintaining performance indicators by increasing speed and reducing electrical losses, two phase current regulators of the stator, three comparators, two demodulators, two zero-organs and a sawtooth generator were introduced the voltage connected by the output to one of the inputs of the first comparator and to the first inputs of demodulators, the second inputs of which are connected to the outputs of the angular position sensor through the corresponding zero, while the outputs of the demodulators are connected respectively to the first inputs of the second third comparators , the first inputs of the stator phase current regulators are connected to the corresponding outputs of the transducer of the coordinate receiver, the second i inputs are specified to the outputs of the corresponding sensors of stator current currents, and the outputs of These controllers are connected respectively to the BTopbiM inputs of the second and third comparators connected to the outputs of the control inputs of the power amplifier, the output of the exciter current regulator connected to another input of the first comparator connected to the output of the control input of the exciter, output of the transverse solenoid reference unit: The stator current is connected to the first control input of the coordinate converter, the second control input of which is connected to the output of the speed regulator. Proofreader L. Patay