SU1054863A1 - Ac electric drive (its versions) - Google Patents

Abstract

The electrical drive with an asynchronous motor contains a series circuit comprising an in-phase current sensor (1) of the stator of the short-circuit asynchronous motor, a coordinate converter (2), a phase-sensitive rectifier unit (3), and a controllable power source (4) which is connected to the stator windings of the asynchronous motor (5). The other output of the in-phase current sensor (1) is connected to the control input (7) of a frequency generator (8) for the rotor currents, whose output is connected to the input (9) of a reference signal former (10). The other input of the latter is connected to the output of the reference frequency adjuster (12) and its outputs are connected to the reference signal inputs (13, 14, 15) of the unit (3). The electrical drive also contains a rotor rotation frequency multiplier (18), whose inputs (19, 20) are connected to the outputs of the rotation angle sensor (6) of the rotor and of a reference frequency adjuster (12), and whose output is connected to the input (21) of the reference signal former (10). At the same time, the outputs of a sinusoidal signal generator (17) are connected to the inputs (22, 23) of the coordinate converter (2). <IMAGE>

Description

reference function driver, active rotor current output, output to the information input of the first coordinate transducer, and output control of the rotor current frequency frequency output of which is connected to the second input of the reference function former, with the aim of improving the accuracy of torque control , the reference signal generator is provided with a third output, its second output is performed by a multi-factor, the driver of the reference functions is provided with

A third input and a frequency multiplier with two inputs, one of which is connected to the third output of the reference signal generator and the other to the angle, the output of the frequency multiplier is connected to the third input of the disputable functions generator, the second output of the reference signal generator second coordinate transducer, and the outputs of the driver reference functions connected to the inputs of the reference signals of the first coordinate transducer.

The invention relates to electrical engineering and can be used to drive the mechanisms of metal-cutting machine tools, robots, manipulators and in other areas that require a high-speed high-frequency AC electric drive, made on the basis of an asynchronous electric motor with co. “Shut the rotor.

Known is an AC electric drive containing an asynchronous motor connected in series between a first coordinate converter and an energy / output converter connected to the stator winding of an asynchronous electric motor, in the air gap of which Hall sensors are located, the outputs of which are connected to a hegeal (reference) driver. The outputs of which are connected to the inputs of the reference signals of the first and second coordinate transducers, the information inputs of the last connection us with current sensors stator winding of the asynchronous motor, and outputs - through regulators constituting the stator current (active and reactive) coupled to inputs of the first coordinate informatsionimi transducer.

The torque and magnetic flux reference signals of the asynchronous electric motor (active and reactive stator current signals) in the form of DC voltages are respectively fed to the inputs of the stator current controller components, the output signals of which are converted in the first coordinate transducer to the phase current reference signals, according to which the energy converter generates the necessary currents in the stator winding of an asynchronous electric motor.

In accordance with the currents of the stator winding, the required torque and magnetic flux of the asynchronous electric motor are formed, the latter being measured by the Hall EMF sensors.

. The signals from the Hall EMF sensors are processed in the harmonic function generator and are represented as the angular position of the asynchronous electric motor in terms of the harmonic functions. These normalized (reference) functions are used in coordinate transducers: in the first coordinate transducer, the task for the total stator current is formed in accordance with the tasks of the active and reactive current from the outputs of the stator current controller components; in the second coordinate transducer signals are generated about the real active and reactive currents

j.acHHxpOHHoro electric motor,

which are used as feedback signals on the components of the stator currents and are received

. respectively, at the regulator inputs of the stator current components. So

Thus, the signals of the EMF sensors of the Hall are involved in the formation of the main control signals of the drive and significantly (determine the accuracy of its operation l.

The disadvantages of the known electric drive are the low accuracy of control of the torque and magnetic flux of the induction motor, as well as the complexity of the technical implementation associated with the use of Hall electromotive sensors in the electric drive, which require a special design (or modification) of the asynchronous electric motor.

The output characteristics of the Hall EMF sensors have a natural variation and drift, which cannot be completely eliminated, despite the use of special power sources, because of the electric drive circuit.

In addition, the output signals of the Hall EMF sensors contain cogged pulsations of the magnetic flux with the frequency of rotation of the electric drive. At low rotational speeds to combat this. And pulsations, it is necessary to significantly complicate the design of the reference function generator, and the electric drive loses its speed. .

The closest technical solution to the invention is an AC drive containing an asynchronous motor j sequentially switching on a first coordinate converter, a second coordinate converter and an energy converter with an output connected to the stator winding of an induction motor. The information inputs of the first coordinate converter, made in the form of two multiplication blocks and an adder, are connected to the active and reactive stator current adjusters, the outputs of which are also connected to the control inputs of the rotor current frequency generator, which is made according to the type of controlled frequency generator.

The known electric drive also contains a reference signal generator, the first drive of which is connected to the first input of a generator of operative functions composed of a sum of frequencies, a frequency target and a phase splitter, the output of which forms the output of the former and is connected to the inputs of the reference signals of the second coordinate system ( a second generator of the reference signals is connected to a sinusoidal signal generator, the output of which is connected to an angle sensor mechanically connected to the rotor asynchronously motor and the output connected to the inputs of the reference signals of the first coordinate converter.

The signals from the outputs of the setters of the active and reactive currents are converted in the first and second coordinate transducers to the reference signals for the energy converter, which is made in the form of a controlled multiphase current source v. The inputs of the reference signals of the first coordinate transducer receive signals from the angle sensor, which contain information about the rotor frequency of the asynchronous electric motor. The inputs of the reference signal; the second coordinate coordinate transducer from the former of the reference functions receives signals that carry information about the frequency of the rotor currents, since the signals from the output of the generator and the frequency of the currents enter the driver of the reference functions.

Thus, the task and energy converter signals carry, on the one hand, information on the magnitude of the required active and reactive currents, and on the other, information on the required frequency of the rotor currents and the frequency of rotation of the rotor (on the required frequency of the stator currents).

5 The energy converter feeds the asyno-electric motor with the corresponding currents and the electric motor develops the required torque for a given magnetic value.

0 flow t23.

The disadvantage of this electric drive is relatively low. the accuracy of the motor torque control, since the magnitude of the torque depends on the amplitude of the angle sensor signal, which in turn depends on the variations of the transformation coefficient of the rod and varies as a function of the rotation frequency.

0

The purpose of the invention is to improve the accuracy of torque control of an asynchronous motor.

The stated goal is provided

5 in that in the AC drive the reference signal generator is provided with a third output; the driver of the reference functions is; third in the year and introduced a frequency multiplier with two inputs, one

0 of the coils are connected with the output of angle sensors, the other is connected with the third output of the reference signal generator, the output of the frequency multiplier is connected with the third input of the driver

5 reference functions, and the outputs of the sinusoidal signal shaper are connected to the inputs of the reference signals of the first coordinate transducer.

0

The shaper of the frequency of the rotor currents is provided with a synchronization input, and the generator of the reference signals with the fourth output connected with the synchronization input forms the liter of the frequency of the rotor currents.

The shaper of the frequency of the rotor currents can be made as a pulse-width modulator. .

In addition, the input frequency multiplier is connected to the third output of the reference signal generator by one input and the angle sensor by another, the frequency multiplier is connected to the third input of the reference function generator, the second output of the reference signal generator is multiphase and connected with the inputs of the reference signals of the second coordinate converter, and the outputs of the opMI master of the reference functions are connected to the inputs of the reference, signals of the first coordinate converter ..

FIG. 1 to 3 show the embodiments of the proposed AC drive; in fig. 4 - 8 execution of separate blocks of the electric drive; in fig. 9-11 are diagrams explaining the operation of individual nodes of the AC drive.

According to the first variant: the AC drive contains an asynchronous motor 1 (FIG. 1), the first coordinate converter 2 connected in series, the second coordinate converter 3, the energy converter 4, the outputs of which are connected to the output terminals of the stator winding of the asynchronous motor 1.

The outputs of the setpoint generator 5 active current and the setting device b of the reactive current are connected to the control unit of the driver of the frequency generator 7 of the rotor current of the electric motor 1 and to the information inputs of the neipBoro Coordinate converter 2, the driver of the driver 7 is connected to the first input of the driver of the 8 Support Functions, with the second input of which the 8 input Functions, with the second input of which has been connected, with the second input of the driver 7 which is connected to the first input of the driver 8 of the Support Functions, with the second input of which the input of the second input of the input of which 8 has generator 9 of the reference signals Shzkhody shaper 8 is connected to the inputs of the reference signals of the second coordination converter 3. The second output of the generator 9 is connected to the input of the shaper 10 blue signal signals, the outputs of which are connected to the inputs of the reference signals of the first coordinate transducer 2.

On the shaft of the asynch | zone motor 1, an angle sensor 11 is installed, the output of which is connected to the first input of the frequency multiplier 12, the second input of which is connected to the third output of the generator 9.

The shaper 7 of the rotor current frequency can be provided with a synchronization input, and the generator 9 is the fourth input connected to the synchronization input of the shaper 7. Coordinate converter 2 contains multiplication blocks 13 and 14, the output of which is connected to the adder 15 of the coordinate converter 2, and its inputs are formed by the inputs of blocks 13 and 14.

Shaper 8 support functions

contains sequentially interconnected block 16 of logic installed at the input of formate, l 8, trigger frequency divider 17 and decoder 18 installed

at the shaper's exit 8.

Coordinate transducer 3 is filled with phase-sensitive rectifiers 19, the first inputs of which form the amplitude inputs of the signals and are connected: with the output of the coordinate transducer 2, and other inputs of the phase-sensitive rectifiers - entered the Reference signals of the coordinate transducer 3.

The multiplier 12 frequency can be made in the form of a shaper 20 increments of the angle and adjustable frequency divider 21.

In the case when the thermal mode of operation of the asynchronous electric motor 1 fluctuates greatly, a temperature sensor 22 is inserted into the electric drive circuit (FIG. 2), and the shaper 7 of the rotor current frequency is provided with a correction input, which is connected to the output sensor of the 22 sensor, the input of which is connected to unit 5 reactive current.

Alternatively, the output of the generator 9 is performed multi-phase and connected to the inputs of the reference signals of the coordinate converter 3, while, as in the first variant, the first output of the generator 9 is connected to the first input of the form-building 8 (Fig. 3), the third to the second input of the multiplier 12 frequencies, and to the inputs of the opsph signals of the first Rocket converter there are connected the outputs of the shaping device 8 of the reference functions. All other connections between the elements of the electric drive remain the same. In the coordinate converter

3 of each of the phase-sensitive rectifiers 19 may be real eHEdHg, for example, according to the scheme / shown in fig. 4. The key 23 with its output is connected to the capacitor 24 and to the input of the operational amplifier 25, the output of which forms the output of the phase-sensitive rectifier 19. The switching input of the switch 23 Forms an information (amplitude) input phase-sensitive

control 19, and control input

the key 23 forms the input of the reference signal of the said rectifier and, accordingly, the coordinate converter 3.

Fig. 5 shows an example of the implementation of a frequency generator of the rotor current frequency 7, which implements the principle of pulse-width modulation.

A comparator 26 with a hysteresis characteristic is connected at the input of the imager 7 of the rotor current frequency, the output of which is connected to the control input of the trigger-synchronizer 27, which is also equipped with a synchronization input conforming to the corresponding input of the rotor current frequency generator 7.

The output of the synchronizer trigger I forms the output of the driver J7 and is additionally connected to the feedback step 1 composed of a voltage multiplier 28 on the sign of the function of the RC filter 29 whose output is connected to the input of the comparator 26. The output of the adder 30 is connected to the amplitude input of the multiplier 28, the inputs of which form the control. and the correction inputs of the frequency generator 7 of the rotor currents.

For electric drive variants (Figs. 1 and 2), a more complete structural diagram of the driver 8 of the reference functions is shown in Fig. 1. b and contains a series of logic 16, a trigger frequency divider 17 and a decoder 18. One of the inputs of the trigger divider 17 frequency and two outputs of the decoder 18 form a three-phase output of the forcing 8. Four inputs of the block 16 of the logic form respectively the inputs of the forcing 8.

The driver 8 of the reference functions for the electric drive variant (FIG. 3) is shown in FIG. 7. Unlike shaper. 8 (Fig. 6} in this driver, two drivers 31 and 32 of harmonic codes, in particular, sine and cosine, are connected to the output of the trigger divider 17 frequency.

FIG. 8 shows the coordinate converter 2 for the electric motor variant (FIG. 3). Instead of the usual blocks 13 and 14 multiplications, multipliers 33 and 3 of the voltage are applied to the sign of the function and digital-to-analog converters i 35 and 36 connected in series with them, the outputs of which are connected to the adder 15.

In the first embodiment (Fig. 1), the electric drive works in the following manner.

The signals 0. setting the reactive and active stator currents are generated by setters 5 and 6 and fed to the information inputs of the first coordinate converter 2 (to the inputs of multiplication blocks 13 and 14) and to the control inputs of the rotor current frequency generator 7. Strictly speaking, these signals, according to the frequency-current method of controlling the torque of an asynchronous motor, set the active and reactive currents of the rotor, and the current voltage simultaneously and the torque coupling signals of the rotor JIB to the first approximation of the magnetic flux of the asynchronous motor 7.

Uj signals. and Uj are the respective vectors of stator currents in axes q and d coordinates rotating with the frequency of the stator currents, and are represented in the drive as DC voltages.

The Astnurot signals and the Asse tjjft from the generator 10 system signals, where A and are the amplitude and frequency of the reference signals, are sent to the inputs of the reference signals of the coordinate converter 2 (to the other inputs of blocks 13 and 14 multiplication).

At the outputs of blocks 13 and 14, signals U are formed (j / As nujQt; and Uj A COS ujpt, which are added in the adder 15., at the output of which the signal

A1i + uj syluo t + arct-I is formed,

arriving at information inputs.

the second coordinate transformer 3. The magnitude of the signal is DYu + U 3lad

determines the required value of the stator currents. -

In the shaper of the rotor current frequency 7, the signals UQ and U convert: 0. To a signal proportional to the value Uq / Оj and non-magnitude information about the frequency Fp (fp) of the rotor currents. This signal is corrected with the help of the synchronization signal received from the generator 9 of the reference signals, and is fed to one of the inputs of the driver 8 of the reference functions. On the other inputs of this shaper arrive. signals from the generator 9 reference

 signals and from the multiplier 12 frequency. The frequency multiplier for all variants of the electric drive has the same performance and works as follows.

The output of the angle sensor 11 is fed to the input of the imager 20, the angle increments and is converted into a rotor speed code, which with the help of an adjustable frequency divider 21 converts to the output frequency of the multiplier 12, and the scale of the conversion is determined by the frequency of the 5 J signal, which is entered

through the second input of the multiplier 12 (auxiliary input of the 21 frequency divider) from the generator 9 of the reference signals. Thus, the output signal of the frequency multiplier 12 carries information about the rotation frequency of the rotor of the asynchronous motor 1 in some masaggaba and is fed to the input of the shaping unit 8 of the reference functions, the output of which is formed, for example, a three-phase signal carrying information about the sum of the frequencies U / gp and sor and rotor currents. This signal plays the role of reference functions and is fed to the inputs of the reference signals of the coordinate converter 3 (to the inputs of the reference signals of phase-sensitive rectifiers 19).

At the outputs of the coordinate converter 3, signals are generated that carry information about the magnitude and frequency of the stator currents and act as signals for setting the phase currents of the asynchronous motor 1. These signals are fed to the input of the energy converter 4, which is designed as an adjustable current source and which feeds the asynchronous motor with currents whose frequency is equal to

Sh

rsh

Where

p is the number of pairs of poles,

waged2

its proportional. BUT

rank

Thus, the stator currents and rotor currents are controlled in accordance with the setting signals t / n and U, and the torque is controlled according to the frequency-current method of controlling the asynchronous motor.

In order to perform automatic control of torque when controlling the speed and position of the load with the help of an electric drive, the active current setpoint b is implemented as a speed regulator (position), to the feedback input of which information comes from frequency multiplier 12, in particular, incrementing angle G FIG. 1, this link is not shown.

The electric drive according to the second variant (FIG. 2) works in a similar way. The difference lies in the formation of the frequency of the rotor currents. In this electric drive, the frequency of the rotor currents is formed taking into account the actual temperature of the asynchronous motor 1, which allows to take into account the change in the active resistance of the rotor during the operation of the drive. The signal from the temperature sensor 22 is supplied to the corrective

the input of the frequency generator 7 of the rotor, in which the formation of a signal is formed, whose magnitude is proportional to

where C is the coefficient; 6 - change of temperature of the electric motor 1. Thus, the formation of the frequency ujp of the rotor currents is amended

Tj - 0 b, for the formation of which

electric drive (Fig. 2), the signal is fed to the input of the sensor 22 temperature.

In the considered embodiments of the electric drive (Fig. 1 and 2), the inputs of the reference signals of the coordinate converter 2 are received with a normalized amplitude A of sinusoidal signals from the driver 10. Therefore, the signal at the output of the coordinate converter 2 turns out to be strictly proportional to the signals 0. and Lf and independent of the speed of rotation, which improves the torque control accuracy and the rotor flux linkage of the asynchronous motor 1.

In the actuator of FIG. 3, an increase in the accuracy of torque control is achieved due to the fact that the reference signals of the coordinate converter 2 receive the normalized reference signals from the driver 8 of the reference functions. At the same time to the inputs of the reference signals of the coordinate Converter 3 receives the normalized reference signals from the generator 9 reference frequencies. In this electric drive, the signals at the output of the coordinate converter 2 carry information about the magnitude of the stator current, as. and in variants of the electric drive (Fig. 1 and 2), only the frequency of this signal contains, besides the frequency tjoj, the frequency p to gp + tOp. Otherwise, the operation of the actuator of FIG. 3 is no different from the operation of the actuator of FIG. 1 and 2.

On. 3 shows a simplified version of the electric drive for the case when the flow coupling is not regulated and does not take into account the temperature of the electric motor 1. Actually, the electric drive and according to this variant can be supplemented with a reactive current setter 5, a temperature sensor 22 / and the rotor current frequency generator 7 can be equipped with synchronization inputs and correction connected respectively to the outputs of the generator 9 of the reference signals and the sensor 22 of the temperature.

Consider the work of the proposed 5 th electric drive (Fig. 1-3) on the basis of the work of individual nodes (Figs. 4-8).

The phase-sensitive rectifier 19 can be implemented as shown in FIG. 4. At the instant of action of the pulse KQ, coming from the output of the shaper 8, the switch 23 closes and the value of D of the stator current, which is the instantaneous value of the stator phase current, is quickly set on the capacitor 24. It Then, the switch 23 is opened, and the stator current j value on the capacitor 24 remains unchanged until the next key switch 23. To keep the capacitor 24 unbroken 15 and transmit the stator current value without changes, the amplifier 25 is executed with the greatest possible impedance. The frequency of the arrival of Ko pulses is equal to f l (pfgp tfgpj 20

Coordinate transducer 3 contains phase-sensitive transducers 19, for example, by the number of phases of the electric motor. One 25 and the same signal goes to the inputs of all fuzzers 19 () where Jj. - the amplitude of the stator current,

 I l 7

proportional to signal a. The obtaining of a three-phase signal at the 30th output of the coordinate transformer 3 is illustrated by graphs (Fig. 9), where a sinusoidal signal with an amplitude of 3s and a frequency

o 2Jrf 2J7 / T; 35

impulse signals Kg, K, 2о 240 phase-sensitive rectifiers 19 and corresponding in time t by the value of To / C. The value of the signals L, J; The 40 2, 2 ez outputs of the rectifiers 19 form a three-phase signal system, which is their signal of setting the stator current for the energy converter. 4. Expression 45 for the output signal of the rectifier 19 (FIG. 4) when arriving at

its input signal Jj.cos (2Jfo) has the form

(p dr1 p | + Ch.5a

FIG. 5 shows a diagram of the former 7 of the frequency of rotor currents, made in the form of a pulse-width. Egenerator. The switch 26 and the trigger 27 surround the direct circuit of the pulse width modulator, and the multiplier 28 on the sign and the CC filter 29 form a feedback circuit. Thanks to the inclusion of these elements 60 at the output of the trigger 27 (output of the forger 7). Setting the pulse-pulse oscillations, the amplitude of which is constant (figure 10), the period T is determined by the area of his- 5

the comparator 26 and the time constant of the RC filter 29. At the first control input of the imaging unit 7 (Fig. 5), the C / L signal is received. In the imaging unit 7, the ratio m - m - t.s.

Ud

where fcj, is the pulse duration — at the output of the driver 7. Due to this property of the pulse-width modulator, all requirements imposed on the ro-ora frequency of the driver 7 can be realized.

So, for example, in the variants of the electric drive (Fig. 1); the signal Ug takes the value Ua, - for which one input of the adder 30 (control inputformer 7) receives a signal (, the signal Ug-O At the output of the imager 7 in this case is formed latitude -modulated signal for which equality is true

H "

: i,

The trigger 27 provides for the formation of the period T and the pulse duration t p, a multiple of the period of the synchronizing signal from the generator 9 of the reference signals.

In the case when the temperature of the asynchronous electrodvitator 1 is measured, the input of the adder 30 (correction input of the former 7) receives the signal U2 -KciQUj from the temperature sensor, cdeK -. The conversion ratio of the function (-f + otQ to function 7 / I Koi-Q In this case, the temperature sensor 22 is supplied with a voltage proportional to the signal U In this case, the signal 00 C (- (- (ot.Cl)) and the frequency of the rotor currents is proportional to the signal

At U {l-Kot (3).

FIG. 10 shows an example when the signal Ucj is changed, and according to IT there is a c-ort-pulsed signal at the output of the former 7.

According to the second variant of the electric drive, the shaper of the frequency of the rotor currents can be performed with

and -const

and and, vcrr

as well as with a temperature sensor.

In all variants of the drive. According to the invention, the inputs of the driver of the 8 support functions from the generator 9 of the reference signals receive signals of two reference frequencies F2, OT of the multiplier 12 frequencies a signal with a frequency F- and from the forming processor 7 a width-modulated signal. As a result, a multi-phase signal is generated at the output of the imaging unit 8. The frequency of this signal is equal to fo (pfp p the difference. - Oe. The output signal of the trigger divider 17 frequency ,,, and the component f JJ ± p, - by changing the average number of pulses applied to the input of the frequency divider 17 during the time interval specified by the period of the pulse width pulse generator 7, for which the block 16. logic implements the function I . P Pj p where fb is the latitude of a pulse. P, is the pulse sequence containing excess pulses relative to the carrier frequency F2 is the pulse sequence in which the number of pulses from FO is cut, which coincides with the number of beams if1 The average frequency at the output of the divider 17 is equal to the EGR and the output is f. If ti r, then the BC and the output frequency f, fjjt prevail. The deviation of the output frequency from f. corresponds to the frequency of the rotor currents and, respectively, we have. The difference in the operation of the driver 8 of the support functions in FIG. 7 from the driver of the support functions in FIG. 6 is that the sine code Mg;, is formed on its output. and cosine Njjjjg, varying with frequency f, t (pfBp ± f) (Fig. 11). For this, the shapers of 31 and 32 codes of harmonic functions are applied, the inputs of which receive signals from the trigger splitter 17 frequency. The diagrams (Fig. 11), which explain the operation of the imaging unit 8 (Fig. 7), show how the sine codes Ng and the cosine of the MSRP half-cycle signals form from the periodically linearly varying N code at the output of the divider 17 in the fs world controller 31 and 32 S and C. The accuracy of the approximation of sine and cosine is determined by the value, where n is the number of bits of the frequency divider 17. Shaper 8 support functions (designed for a variant of the electric drive (Fig. 3), in which the coordinate converter 2 is made according to the scheme of Fig. 8. In this variant. The signals Ujj and and "in the coordinate converter 2 are fed to the inputs. Multipliers 33 and 34 eg. function, digital-to-analog converters 35 and 36, and then adder 18. Sine and cosine codes from the driver 8 are sent to the digital inputs of converters 35 and 36, and the alternating signals tUo and tUj are given to their inputs of reference voltages, the sign of which determined by the logical level m (O or 1). half period signals S and C. At the outputs of converters 35 and 36, cosine and sinusoidal signals are formed with amplitudes equal to Lfj and Uc, respectively, and frequency (pfgp ± fp). At the output of adder 18, a signal is generated with frequency and amplitude. In proportion to the value of lU.-tU, SI q. This signal is converted in the coordinate converter 3 using pulse signals of frequency f with phase difference 4s-,. the reference signals coming from the hegenrator 9 into the three-phase signal of setting the stator phase currents, which acts on the input of the energy converter 4. The proposed electric drive has high control characteristics — the torque and magnetic flux of the asynchronous electric motor are determined by the reference signals and the LF depend on the speed of rotation. This is achieved due to the fact that the amplitude of the angle sensor signals is excluded from the channel for the formation of the amplitude of the stator current. In addition, the drive is technically more advanced. There is no O17 restriction on the type of application of the angle sensor: either code or pulse, or a sensor based on SCRT can be used. At the same time, the number of pole pairs at SCOT may be different from the number of pole pairs of an asynchronous electric motor, which greatly simplifies the technical implementation. The use of a pulse-width modulator as a frequency driver for rotor currents eliminates complex analog functional blocks, which simplifies the electric drive and increases the accuracy and reliability of operation in the case of x when flow control and temperature control of an asynchronous electric motor is required. The use of conversion techniques and equipment allows in many functional units of the electric drive to refuse to adjust the working points, as required by the technical solutions on the elements of analog equipment. When using the proposed electric drive in closed-loop speed control systems and the position of the load, installation of special speed and angle sensors is not required; speed information is necessary for the stability of the drive; it can be obtained using a frequency multiplier from the output of the angle increment generator.

 I I

/five

nineteen

sh

eight

ffl

ha

synchronization Figure 5

2.6

72

4g. 7 st -eXj Bb / j (0dr n m gp

Af -1 / V- /

N,

Sin

.

s-i

/ Veos

-. r1 f-i

Claims (4)

1. An AC electric drive containing an asynchronous electric motor, the first coordinate converter, the second coordinate converter and the energy converter connected in series with the output connected to the stator winding of the asynchronous electric motor, an angle sensor mechanically connected to the rotor of the asynchronous electric motor, current frequency generator, rotor, serially connected reference signal generator and reference function generator, active and reactive current drives, in the strokes of which are connected to the corresponding information inputs of the first coordinate converter and the corresponding control inputs of the rotor current frequency generator, the output connected to the second input of the reference function generator, the outputs of which are connected to the reference signal inputs of the second coordinate converter, the sinusoidal signal generator, the input connected to the second output of the generator reference signals, characterized in that, in order to improve the accuracy of controlling the moment of the electric drive, ge the reference signal generator is provided with a third output, the reference function generator is the third input and a frequency multiplier is introduced with two inputs, one of which is connected to the third output of the reference signal generator, and the other is connected to the angle sensor, the output of the frequency multiplier is connected to the third input of the reference function generator, and the output of the sinusoidal signal former is connected to the inputs of the reference signals of the first coordinate I converter. / 2. Electric pop. 1, .o. characterized in that the rotor current frequency generator · is equipped with a synchronization input, and the reference signal generator has a quarter ”output connected to the synchronization input of the rotor current frequency generator. 3. Electric drive according to π. 1, the fact is that the rotor current frequency driver is made as a pulse-width modulator. . 4. An AC drive comprising an induction motor, a first coordinate converter, a second coordinate converter and an energy converter connected in series with an output connected to the stator winding of the asynchronous electric motor, an angle sensor mechanically coupled to the rotor of the asynchronous electric motor, frequency generator of the rotor currents, in series . Connected signal generator and reference signal generator. _M SUn., 1054863 reference function generator, active rotor current generator, connected to the information input of the first coordinate converter and the control input of the rotor current frequency driver as an output, the output of which is connected to the second input of the support function generator, characterized in that, in order to increase the control accuracy the moment of the electric drive, the reference signal generator is equipped with a third output, its second output is multiphase, the support function generator is equipped with a third input and a frequency multiplier with two inputs, one of which is connected to the third output of the reference signal generator, and the other to the angle sensor, the output of the frequency multiplier is connected to the third input of the reference function generator, the second output of the reference signal generator is connected to the reference signal input of the second coordinate converter, and the outputs the driver of the reference functions are connected to the inputs of the reference signals of the first coordinate converter.