RU2483421C1 - Device to control induction motor - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: device comprises an autonomous voltage inverter, power outputs of which are connected via current sensors to stator windings of an induction motor, a state observer, and a unit of drivers, outputs of which are connected to control inputs of the autonomous voltage inverter, at the same time power inputs of the autonomous voltage inverter are connected to outputs of a non-controlled rectifier, inputs of which are connected to a source of three-phase AC voltage, the unit of drivers is connected to outputs of a WPM-generator, besides, the state observer is a Luenberger observer, in the proposed device the interface unit is also serially connected with an input filter, the first summator, a PI controller of speed, the second summator, the first PI controller of current, the first and second converters of coordinates, the Luenberger observer, the third summator, a PI controller of flux linkage, the fourth summator, the second PI controller of current, the first converter of coordinates and the WPM generator. The interface unit is connected to the third summator. The first summator is connected to a fuzzy speed controller, the output of which is connected to the second summator. The Luenberger observer is connected with the first summator, the first and the third converters of coordinates. Outputs of the above current sensors are connected to inputs of the second converter of coordinates, and the interface unit is connected to a PC.

EFFECT: reliability improvement.

1 dwg

Description

The invention relates to the field of electrical engineering, namely to the control of induction motors.

A control device for an asynchronous electric motor is known, comprising an asynchronous motor, a PWM inverter, a speed sensor, a coordinate converter, a current regulator, an integrator, a current change command generator, voltage change command generation schemes, angular rotation speed change commands, modulation depth change commands , PWM inverter control signals (RU patent No. 2193814, IPC 7 Н02Р 21/00, published on November 27, 2002).

A disadvantage of the known control device is that for its operation it is necessary to equip the engine with a speed sensor, which reduces the scope of this control device.

A known asynchronous motor control system, which is selected as a prototype, consisting of an input unit for a given speed of an asynchronous motor, a mismatch unit, a voltage regulator, a driver block, the outputs of which are connected to the control inputs of a stand-alone voltage inverter, stand-alone voltage inverter, current induction speed sensor engine, unit for calculating the synchronous speed of an induction motor, state observer (RU patent No. 2390091, IPC 8 Н02Р 21/08, Н02Р 21/13, Н02Р 23/08 , Н02Р 27/06, published on 05/20/2010).

A disadvantage of the known control system is that to calculate the electric rotational speed of the engine rotor by a state observer, it is necessary to use a speed sensor, which reduces the reliability of this system.

The objective of the invention is to increase the reliability of motor control.

The problem is solved due to the fact that the control device of an induction motor, as well as in the prototype, contains an autonomous voltage inverter, a state observer and a driver block, the outputs of which are connected to the control inputs of the autonomous voltage inverter.

According to the invention, the power outputs of an autonomous voltage inverter through current sensors are connected to the stator windings of an induction motor, and the power inputs of an autonomous voltage inverter are connected to the outputs of an uncontrolled rectifier, the inputs of which are connected to a three-phase AC voltage source. The Luenberger observer was chosen as a state observer. The driver block is connected to the outputs of the PWM generator. An input filter, a first adder, a PI speed controller, a second adder, a first PI current controller, a first coordinate converter, a second coordinate converter, a Luenberger observer, a third adder, a PI flux linkage regulator, a fourth adder, and a second PI current regulator, first coordinate converter, PWM generator. The interface unit is connected to the third adder. The first adder is connected to a fuzzy speed controller, the output of which is connected to the second adder. The Luenberger observer is connected to the first adder, the first and third coordinate converters. The outputs of the current sensors are connected to the inputs of the second coordinate converter, the outputs of which are connected to the third coordinate converter, which is connected to the fourth and second adders, and the interface unit is connected to a personal computer.

The proposed device allows to improve the dynamic characteristics and increase the reliability of controlling an induction motor due to the use of a fuzzy speed controller in conjunction with a PI speed controller, as well as the observer Luenberger associated with two adders. Improving the dynamic characteristics of the electric drive is provided by a fuzzy speed controller, which allows you to reduce the dynamic failure of the motor speed when exposed to disturbing signals. The combined use of a PI speed controller with a fuzzy controller provides the drive with astatism perturbation. The use of the Luenberger observer can improve the reliability of controlling an induction motor due to the abandonment of mechanical speed sensors and rotor flux linkage, while a simple mathematical description of the observer reduces the computational resource consumption of the microcontroller required for the procedure of restoring the unmeasured coordinates of the electric drive - rotor speed and flux linkage.

In FIG. 1 shows a block diagram of an induction motor control device.

The asynchronous motor control device contains an autonomous voltage inverter 1 (AIN), the power outputs of which are connected to the stator windings of the asynchronous motor 5 (M) through phase current sensors 2, 3, 4 (DT). The power inputs of an autonomous voltage inverter 1 (AIN) are connected to the outputs of an uncontrolled rectifier 6 (NV), the inputs of which are connected to a three-phase AC voltage source 7 (ITPN). The control inputs of the autonomous voltage inverter 1 (AIN) through the driver unit 8 (DB) are connected to the outputs of the PWM generator 9 (PWM-G). An input filter 11 (VF), a first adder 12 (C1), a PI speed controller 13 (PI-RS), a second adder 14 (C2), a first PI current controller 15 (PI- RT 1), the first coordinate converter 16 (PC 1), the second coordinate converter 17 (PC 2), the Luenberger observer 18 (NL), the third adder 19 (C3), the PI flux linkage controller 20 (PI-RP), the fourth adder 21 (C4), the second PI current controller 22 (PI-RT 2), the first coordinate converter 16 (PC 1), the PWM generator 9 (PWM-G). The interface unit 10 (BI) is connected to the third adder 19 (C3). The first adder 12 (C1) is connected to a fuzzy speed controller 23 (H-PC), the output of which is connected to the second adder 14 (C2). The Luenberger observer 18 (NL) is connected to the first adder 12 (C1), the first coordinate transformer 16 (PC 1) and the third coordinate transformer 24 (PC 3). The phase current sensors 2, 3, 4 (DT) are connected to the second coordinate transformer 17 (PC 2), the outputs of which are connected to the third coordinate transformer 24 (PC 3), which is connected to the fourth adder 21 (C4) and to the second adder 14 ( C2). An interface unit 10 (BI) is connected to a personal computer (not shown in FIG. 1).

As sensors of phase currents 2, 3, 4 (DT), current sensors can be used - an industrial device KEI-0.1. Uncontrolled rectifier 6 (HB) and autonomous voltage inverter 1 (AIN) are structurally made in one device - a frequency converter, which can be used as a Danfoss VLT FC 300 frequency converter. The driver block 8 (DB) can be performed on drivers of the DRI11-10-12-1 OM1K-1 type to control IGBT modules. PI speed controller 13 (PI-RS), PI flux linkage controller 20 (PI-RP), the first PI current controller 15 (PI-RT 1) and the second PI current controller 22 (PI-RT 2) can be performed on operational amplifiers of the type 157UD4 with a capacitor in the feedback circuit. Adders 12 (C1), 14 (C2), 19 (C3) and 21 (C4) can be performed on operational amplifiers of the type 157UD4. The input filter 11 (WF) is a first-order aperiodic link and can be performed on the basis of an RC chain. The first coordinate converter 16 (PC 1), the second coordinate converter 17 (PC 2), the third coordinate converter 24 (PC 3), the fuzzy speed controller 23 (N-PC), the Luenberger observer 18 (NL) and the PWM generator 9 (PWM) -G) can be performed on the basis of a microcontroller type TMS320F2812 company Texas Instruments. The interface unit 10 (BI) can be implemented on the basis of a serial converter of the RS-232 interface.

When the device is turned on, a control signal is sent from a personal computer to an interface unit 10 (BI), from which commands are given simultaneously for the flow coupling and for the rotation speed of the induction motor 5 (M) to the third adder 19 (C3) and the input filter 11 (VF), respectively . From the input filter 11 (WF), the signal enters the first adder 12 (C1), in which it is summed with the negative value of the speed estimation signal from the observer Lüenberger 18 (NL). From the first adder 12 (C1), the signal simultaneously enters the fuzzy speed controller 23 (H-RS) and the PI speed controller 13 (PI-RS). Next, the signals from the fuzzy speed controller 23 (N-RS) and the PI speed controller 13 (PI-RS) go to the second adder 14 (C2), where they are summed with the negative value of the signal of the projection of the stator current vector on the ordinate axis of the rotating coordinate system from the third coordinate converter 24 (PC 3). From the second adder 14 (C2), the signal is supplied to the first PI current controller 15 (PI-RT 1). In the third adder 19 (C3), the job link assignment command and the negative value of the flux linkage estimation signal from the Luenberger observer 18 (NL) are summed. Next, the signal goes to the PI flux linkage regulator 20 (PI-RP), from which it goes to the fourth adder 21 (C4), where it is added to the negative value of the signal of the projection of the stator current vector onto the abscissa axis of the rotating coordinate system from the third coordinate transformer 24 (PC 3 ) From the fourth adder 21 (C4), the signal enters the second PI current regulator 22 (PI-RT 2). The first coordinate converter 16 (PC 1) simultaneously receives signals from the first PI current controller 15 (PI-RT 1), the second PI current controller 22 (PI-RT 2) and the signal for estimating the rotation angle of the flux linkage vector from the Luenberger observer 18 ( NL). From the first coordinate converter 16 (PC 1), the phase voltage signals are simultaneously transmitted to the PWM generator 9 (PWM-G) and to the second coordinate converter 17 (PC 2). From the PWM generator 9 (PWM-G), the signals go to the driver block 8 (DB). The second coordinate converter 17 (PC 2) also receives signals from the sensors of phase currents 2, 3, 4 (DT). From the second coordinate transformer 17 (PC 2), the projections of the stator current and voltage vectors on the axis of the fixed coordinate system are transmitted to the Luenberger 18 observer (NL). The third coordinate transformer 24 (PC 3) receives the signals of the projections of the stator current vector on the axis of the stationary coordinate system from the second coordinate transformer 17 (PC 2). From a source of three-phase alternating voltage 7 (IIT), the signals are fed to an uncontrolled rectifier 6 (HB). An autonomous voltage inverter 1 (AIN) simultaneously receives a rectified voltage signal from an uncontrolled rectifier 6 (NV) and control signals of the inverter power keys from the driver unit 8 (DB). From an autonomous voltage inverter 1 (AIN), the signals are fed to the phase current sensors 2, 3, 4 (DT) and then to the stator windings of the asynchronous motor 5 (M). Thus, the claimed device allows you to adjust the speed and flux linkage of the induction motor 5 (M).

Claims (1)

An asynchronous motor control device comprising an autonomous voltage inverter, a state observer and a driver block whose outputs are connected to the control inputs of the autonomous voltage inverter, characterized in that the power outputs of the autonomous voltage inverter through current sensors are connected to the stator windings of the asynchronous motor, and the power inputs of the autonomous inverter voltages are connected to the outputs of an uncontrolled rectifier, the inputs of which are connected to a three-phase AC voltage source, in ka As a state observer, a Luenberger observer is selected, the driver block is connected to the outputs of the PWM generator, the input filter, the first adder, the PI speed controller, the second adder, the first PI current controller, the first and second coordinate converters, the Luenberger observer are connected to the interface unit in series third adder, PI flux linkage regulator, fourth adder, second PI current regulator, first coordinate converter, PWM generator, while the interface unit is connected to the third adder, first adder It is connected to a fuzzy speed controller, the output of which is connected to the second adder, and the Luenberger observer is connected to the first adder, the first and third coordinate converters, and the outputs of the current sensors are connected to the inputs of the second coordinate converter, the outputs of which are connected to the third coordinate converter, which is connected to the fourth and second adders, and the interface unit is connected to a personal computer.