SU699639A1 - Electric drive with induction squirrel-gase machine - Google Patents

Description

(54) ELECTRIC DRIVE WITH ASYNCHRONOUS CORE OF TKO CLOSED UTOR, ML SHI 1chzrov, the first inputs of which are connected to the outputs of the direct conversion unit, and the second inputs outputs - to the frequency converter. By this, the output signal of the zero-component controller is added to the signals for setting the phase voltages of the converter, which contributes to its suppression. The drawing shows a functional diagram of the drive. The electric drive contains an asynchronous short-circuited motor 1 fed from a frequency converter 2, a speed controller 3, the feedback input of which is fed to a signal from the output of a speed sensor 4 connected to the motor shaft, regulators of the stator current vector , sensors of phase currents 8, 9, 1О,. "also a slip control unit 11, including an angular position sensor 12 of the machine shaft, a reference voltage generator 13 and a slip regulator 14, to the control input of which a reactive component is given the stator current and the output signal of the speed controller 3. The drive also contains blocks of direct 15 and 16 inverse coordinate transformations, included respectively in the forward channel of adjustment of the stator current vector components and feedback channel. The blocks of direct and inverse coordinate transformations are controlled by the output signals of the slip controller 14 and the reference voltage generator 13. The control circuit of the zero component of the stator current contains a sensor 17 and the controller 7 of the zero component, as well as a block of adders composed of adders 18 20. Output signals from the phase currents 8, 9, 1O are connected to the input of sensor 17, as well as the output signal of the reference voltage generator 13. The output of the zero stator component current sensor is connected to the input of regulator 7, the output of which is fed to the adders 18, 19, 2O, where it is algebraically summed with the output signals of the direct coordinate conversion unit 15. The output signals of the adders 18, 19, 20 are fed to the input of the transducer frequency body. The device works as follows. The inputs of the zero current component sensor 17 are supplied from the outputs of sensors 8, 9 and 10, signals proportional to the instantaneous values of the stator phase currents of the motor. A sensor 17 forms at the input a signal proportional to the zero component of the current vector by summing the output signals of the sensors 8, 9 and 1 O. The summation operation can be carried out, for example, according to the modulation scheme — summing on transformers-demodulation, using a high-voltage signal from the generator 17 for the modulation and demodulation of the high-frequency signal from the output of the sensor 17 as an active adder on the operational amplifier direct current connection from the output of the generator 13 to the input of the sensor 17 can be excluded. In the event that the zero component of the stator current vector is not equal to zero, the output of sensor 17 is a signal that supplies the input of the zero-component regulator of current 7 and is compared with the reference signal of this state of 5) (in this case, the reference signal is zero ). As a result of the conversion by the regulator 7 of the error signal, at the output of this regulator a compensating signal is formed. This signal is fed to the inputs of the adders 18, 19, 2O, where it is summed with the output signals of the regulators 5 and 6 of the components of the stator current vector, previously converted to the stator coordinate system using the unit direct displacement conversion unit 15. The output signals of the adders 18, 19, 2O affects the phase voltages of the frequency converter 2, and the specified compensation signal from the output of the regulator 7 provides for the suppression of the zero component of the current in the phase windings of the induction motor. Thus, the introduction into the control system of an asynchronous motor of sensor 17, regulator 7, and adders 18, 1 9, 2 O eliminates the adverse effect of the zero component of the stator current vector, which creates additional braking torque, increases energy loss and heat the motor windings. The suppression of the zero component substantially increases the technical and economic 4tx: KHe indicators of the electric drive with asynxii-MiFMii Mliiimroii)) g: |) PI11 (IIC1 with iarest)

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An electric drive with an asynchronous short-circuited machine, containing a frequency converter connected to the asynchronous machine, a direct coordinate conversion unit with connected to its inputs regulators of the active and reactive components of the stator current, phase current sensors connected through the reverse coordinate conversion unit to the feedback inputs mentioned sliders, and a slip control unit with an angular position and generator generator connected to the inputs of direct and inverse coordinate transformation blocks rum of the reference voltage, characterized in that, in order to improve the quality of regulation, a sensor and a zero component regulator of the current of the current

the torus, as well as the block of adders, the first inputs of which are connected to the outputs of the block of direct coordinate transformation, the second inputs through the said controller and the zero-component sensor

the stator current is to the phase current sensors, and the outputs are to the X frequency converter.

Sources of information taken into account in the examination

1. The patent of Germany No. 1941312, cl. 21 C 59/36, 1971,

2. Brodovsky V. N., Ivanov E.S. Contactless ektrotrotrivod with frequency-current control for closed-loop control systems. M., Electricity

No. 10, 1967.