SU1610589A2 - Method and apparatus for controlling twin-supply motor based on induction motor with phase-wound rotor - Google Patents

Abstract

The invention relates to electrical engineering, can be used to control a dual-feed motor based on an asynchronous motor with a phase-rotor, for example, in a traction electric drive. The aim of the invention is to increase the efficiency by reducing the losses in the stator steel after switching to the opposite rotation of the magnetic field and the rotor. This goal is achieved by maintaining the same current frequency in the stator and rotor windings of the induction motor 1, which is equal to half the rotor speed when the specified rotor frequency exceeds the frequency of the master oscillator 31 to a two-phase sinusoidal voltage. A third arithmetic unit 28, a frequency comparator 30, a controlled analog switch 32, a second integrator 21, a second adder 20, multipliers 18.19, a stator current conversion unit 5 and a sensor 4 for phase currents are introduced into the device implementing the proposed dual-feed motor control method. the stator. This ensures the minimum total losses in the stator and rotor steel and the minimum electrical losses in the copper of the windings by maintaining the orthogonality of the stator current vectors and the resulting magnetic flux in the air gap of the machine, thereby increasing efficiency. 2 sec. f-ly, 2 ill.

Description

Barely moving to the opposite rotation of the map floor and rotor This goal is achieved by maintaining the same current frequency in the stator and rotor windings of the induction motor 1, equal to half the rotor speed, exceeding the specified rotor frequency of the master oscillator 31 of a two-phase sinusoidal voltage. The third arithmetic unit 28, a frequency comparator

30, controlled analog switch 32, second integrator 21, second adder 20, multipliers 18, 19, stator current conversion unit 5 and sensor 4 stator phase currents "This ensures the minimum total losses in the stator and rotor steel and the minimum electrical losses in copper winding maintaining the orthogonality of the stator current vectors and the resulting magnetic flux in the air gap of the machine, thereby increasing the efficiency of .2 sec.

f-ly, 2 silt

The invention relates to electrical engineering and can be used to control a dual-feed motor based on an asynchronous motor with a phase-rotor, for example, in a traction electric drive, rowing (in icebreaking type vessels)

The aim of the invention is to increase efficiency by reducing losses in the stator class after switching to

counter-rotation of the magnetic field and the rotor

Fig. 1 shows a functional diagram of a device for controlling a dual power supply implementing the proposed method; FIG. 2 shows the dependence of the stator frequency (core) of the CO and the rotor (excitation) of the EEG on the rotation frequency r} (, o

The device for controlling the dual power supply contains an asynchronous motor 1 (FIG. 1) with a phase rotor, the stator and rotor windings of which are connected to the outputs of converters 2, 3 stator frequencies and rotor frequencies, respectively. Sensor 4 of the stator phase currents is connected to control inputs stator current conversion unit 5 Sensor 6 of the stator voltage is connected by outputs to the inputs for reference signals of the stator current conversion unit 5 and to the inputs of the stator current frequency sensor 7, the output of which is connected to the second a control input of the frequency converter stator blocks B and 9 specifying the amplitude of the stator voltage and the rotor

five

0

50

5 Q s

connected by outputs to the first control inputs of converters 2, 3 stator and rotor frequencies respectively Block 10 converting magnetic fluxes is connected by inputs to the outputs of Hall EMF sensor 11 and sensor 6 of phase voltages, and outputs connected to inputs of quadrators 12 and 13 o First adder The 14 inputs are connected to the outputs of the quadrants 12 and 13, and the output is connected to the first input of the comparison unit 15, the second input of which is connected to the output of the magnetic flux amplitude setting unit 16. The first integrator 17 is connected to the output of the comparison unit 15, and the output is connected to the third control input of the converter 3 of the rotor frequency. The multipliers 18 and 19 are connected by inputs to the outputs of the stator current conversion unit 5 and the magnetic flux conversion unit 10 The inputs of the second adder 20 are connected to the outputs of the multipliers 18 and 19, and the output through the second integrator 21 is connected to the third control / input of the stator frequency converter 2 filter 22 is connected to the outputs of the sensor 6 phase stator voltages, and the output is connected to the input of the first unit 23 for direct coordinate conversion. The input of the second filter 24 is connected to the sensor outputs 25 phase rotor voltages and out d is connected to the input of the second block 26 forward coordinate converting first input of the first arithmetic unit 27 connected to the output of the first block 23 forward pre51

the formation of coordinates, and the second input with the output of the second block 26 of the direct coordinate transformation. The output of the first arithmetic unit 27 is connected to the first inputs of the third 28 and second 29 arithmetic units and to the first frequency input of the comparator 30 The output of the master oscillator 31 of a two-phase harmonic signal is connected to the second input of the second arithmetic unit 29 and to the second input of the frequency comparator 30. The input of the controlled analog the switch 32 is connected to the output of the second arithmetic unit 29, and the control input is connected to the output of the frequency comparator 30. The second input of the third arithmetic unit 28 is connected to the control emogo analog switch 32, and an output - to an input of the inverse transform block 33 the coordinates which in turn is connected to the input of block 34 generating control pulses, the output of which through .delitel 35 connected to the second control input of frequency converter 3 rotor.

The device for driving the dual power supply works as follows.

sinWot CosUpt - cosuJot-sinCOft sin (tOo-a) t sinGD, t; cosGJgt.cosGJi-t - sinCOot-sinGJ t cos (COo-Wp) t cosCO.t,

where is the coo output frequency setting

generator of two-phase sinusoidal voltage;. COyi- angular frequency of rotation of the rotor;

TS SOO-Wr.

From the output of the second arithmetic unit 29, the signal is fed to the input of a controlled analog switch 32, the control input of which receives a control signal from the output of the frequency comparator 30 The first and second inputs of the comparator are supplied from the outputs of the first arithmetic unit 27 cosdjpt and master oscillator 31 phase harmonic signal coscOot. When the frequency of the sinusoidal signal at the first input of the comparator 30 becomes greater than the frequency of the sinusoidal signal at its second input, a logical zero signal is generated at the output. With the frequency of the signal at the first input of the frequency comparator 30 less 2

The power inputs of the transducers, 3 stator and rotor frequencies, and control blocks supply the supply voltage. From the signals of blocks 8, 9 of the setting of the amplitudes of the stator and rotor voltages, rectifier m1 {thermal links of the corresponding frequency converters begin to work.

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At the first moment, the control signals of the inverter links of the transducers 2, 3 of the stator and rotor frequencies are missing. Accordingly, the signal

The 5 nal at the input of the first arithmetic unit 27 is zero. The master oscillator 31 two-phase harmonic signal produces a two-phase sinusoidal low-frequency signal

20 frequency of 6-10 Hz, which is fed to the second input of the second arithmetic unit 29. The first input of block 20 receives a signal from the output of the first arithmetic unit 27. In the second arithmetic unit 29, two-phase sinusoidal signals are converted with according to the expressions:

0

five

0

five

more than at the second, a signal of a logical unit is generated at the output. At the initial moment, the rotor of the engine is immobile (Op 0), respectively, the signal at the input of the frequency coherent device 30 has the level of the logical unit.

If the control input of the switch 32 has a logic one level, the switch is closed and the input signal is output without any changes. If the matching signal has a logic level of zero, the controlled analog switch is open and the signal at its output is zero,

At zero rotor speed (CO | 1 0), the control input of the controlled analog switch 32 has a logic level, so the signal at its output repeats the input signal

From the output of the controlled analog switch 32, the signal is fed to the second input of the third arithmetic

unit 28, to the first input of which a signal is output from the output of the first arithmetic unit 27V to the third

sinO, t-cusCO t - cosO, t sinMft sin (G), - Ca) t, cosQ, t-costOpt - sinCO, t .sinOj.t cos (CO, -Q t.

From the output of the third arithmetic unit 28, the signal is fed to the input of the inverse coordinate conversion unit 33. After converting the inverse coordinate transformation in the block 33, a three-phase sinusoidal signal passes through the control pulse generator 34 and the divider 35 with the division factor K 2 and enters the second control input of the converter. 3 rotor frequencies.

Since at the initial moment of time the rotation frequency of the rotor OEP O, then after passing through the second 29 and third 28 arithmetic blocks and dividing by the divider 35, the signal will have a frequency

G3 Qo / 2

COf frequency. is the initial excitation frequency (current frequency

rotor) about

An alternating three-phase current with a frequency (OED / 2) begins to flow through the winding of the stationary rotor, as a result of which a voltage of the same frequency is induced in the stator winding

CO Wf COO / 2,

sinQt cosCO | t - cosQt. sinoD t sin (W-COf) t cosOt-cosQ t - sinwt. cos (,

where COf is the frequency of the rotor currents (excitation frequency); 03 - stator current frequency (core); Oer 63- tt) f- rotational speed

rotor about

Since with a stationary rotor, the frequencies of the stator and rotor raviy (l) ESS. Frequencies, the frequency of the two-phase signal at the output of the first arithmetic unit 27 is zero (COj, 0). When the rotor is stationary, the changes occur in 105898

The arithmetic unit 28 biphasic sinusoidal signals are converted according to the expression:

where CO is the frequency of the stator current (cor) o

The output signal from the sensor 6 stator phase voltages is fed to the sensor input 7 of the stator current frequency, which generates control signals for the inverter link of the stator frequency converter 2 Alternating three-phase current starts to flow through the stator winding

0) a). with, / 2.

The signals from the sensors of 6, 25 phase stator and rotor voltages are fed to filters 22 and 24, which cause the first voltage harmonics to coincide in phase with the voltages on the stator and rotor windings, respectively. From the filter outputs, the signals go to the inputs of the first 23 and the second 26 blocks of direct coordinate transformation, respectively. After conversion in these blocks, the two-phase sinusoidal signals go to the first and second inputs of the first arithmetic, respectively. block 27, in which the signals are converted according to the expressions:

0

five

a three-phase current that generates rotating magnetic fields in the stator and the rotor. When the stator magnetic field is rotated in the same direction with the same frequency, the field interacts with the rotor magnetic field, creating a rotating electromagnetic moment. When the latter exceeds the moment of resistance of the load on the shaft, the rotor of the engine will begin to rotate,

From the output of the sensor 7, the frequency of the stator currents is then taken off the signal with a frequency equal to the sum or difference of the frequencies of rotation and excitation

C0 (0g + C0

and providing the same speed of rotation of the magnetic fields of the stator and the rotor.

The rotor rotation frequency is controlled by varying the magnitude of the core voltage with the aid of block 8, which sets the stator voltage amplitude.

When the rotor begins to rotate, the signal frequency

.jt SB

From the output of the sensor 6, the stator phase voltage passes through the first filter 22 and after conversion in the first block 23 the direct coordinate transformation is fed to the first input of the first arithmetic block 27 °. The second input of the first arithmetic block 21 is output from the second, block 26 direct coordinate conversion signal frequency CO The frequency of the signal at the input of the first arithmetic unit 27 is equal to the frequency of rotation of the rotor

AZ (, Oh) o

With increasing rotor speed C0f, the frequency of the signal at the output of the second arithmetic unit 29 is equal to

(Oh, coo-wp,

begins to decrease. The frequency at the output of the third arithmetic unit 28 also decreases:

, -Wp Wo-Wr-Wr Wo- 26 ;,

where CO is the output frequency of the third

arithmetic block

Soo

2

Wi

Og 2 wo

-but

When C0 | "9 excitation frequency

C0 is equal to zero — a constant current flows in the rotor winding. With a further increase in the frequency of rotation of the rotor

Sop excitation frequency SdZ changes sign and begins to increase, but with a negative sign. At the time of changing the sign of CO, one of the signals from the output of the third arithmetic

058910

block 28, namely sin (a),) t, reverses the sign. This leads to a change in the phase rotation from the output of the block 33 of the inverse transformation of coordinates to inverse e, which provides a change in the direction of rotation of the rotor magnetic field. In this case, the resulting magnetic field in the air gap of the machine rotates at a frequency Cx).

When the frequency of rotation of the rotor I becomes equal to the frequency of the master oscillator 3G two-phase sine wave 10

15

line voltage (0., frequency sig0

five

0

five

0

five

0

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on the output of the second arithmetic unit 29

CO, CO- 00

and, therefore, at the output of the controlled analog switch 32 is equal to zero. At the same time, the logical signal at the output of the frequency controller of the comparator 30 changes - the logic level becomes zero. As soon as the signal at the control input of the controlled analog switch 32 becomes equal to zero, it is controlled the analog switch stops passing the input signal to the output, so the signal at the second input of the third arithmetic unit 28 is zero

When the rotational speed of the rotor section becomes greater than the output frequency of the master oscillator of the two-phase sinusoidal signal, the output of the third arithmetic unit is removed, the two-phase signal -Qj, since the second input of the third arithmetic unit is zero after the frequency divider 35 frequency signal, the frequency CO -GJp / 2 is fed to the second control input of the converter 3 of the rotor frequency

With a further increase in the speed of rotation of the rotor, the frequency of the excitation is maintained equal to half the frequency of rotation of the rotor

In the electric drive there is an automatic system for maintaining the constancy of the resulting magnetic flux in the air gap of the engine. The output signals from the Hall EMF sensor 11, proportional to the magnitudes of the magnetic fluxes F-5, Fs5 of the air gap across the stator phase axes, are converted using i block 10 of the conversions of magnetic fluxes to goshde, F SM zero frequency, represented in axes x, y, rotating synchronously with the engine field. After erecting the square of the magnetic flux components in quadrants 12 and 13 and adding them to the adder 14, the output signal from the latter is proportional to the square of the amplitude of the magnetic flux F | in the air gap of the engine, is fed to the first input of the unit 15 comparison,. The second input of the comparator unit 15 receives a signal from the unit 16 for specifying the square of the amplitude of the magnetic flux Oi-rtiB air gap A.0

tel p From the output of the comparison unit 15, the error signal DF2 is converted into an offset voltage signal + yi ,,. is supplied to the third input of the transducer T) of the rotor frequency and so changes the magnitude of the excitation current.

1610589 2

stator inverter frequency 2 input Сигна The signal from the output of the second integrator 21 determines the phase displacement of the control pulses until the orthogonality condition of the current core and magnetic flux o is satisfied. The maximum value of the electromagnetic torque of the motor is reached at these values stator current and the resulting magnetic flux in the air gap. .

In view of what has been said in the motor, there is a minimum of losses in the stator and rotor steel, as well as a minimum of electrical losses in the copper windings, thereby increasing the efficiency in comparison with the basic invention.

ten

15

25

Claims (1)

Invention Formula 1o A method of controlling a dual power motor made on the basis of an asynchronous motor with a phase rotor according to aut. No. 1515323, characterized in that, in order to increase efficiency by reducing losses in stator steel, after changing the alternation of the phases of the rotor winding of the frequency of the currents in the stator and rotor windings set equal. 2o A device for controlling a dual-power motor, made on the basis of an asynchronous motor with a phase-rotor, autorum No. 1515323, characterized in that a third arithmetic unit, a frequency comparator, a controlled analog switch, a second integrator, a second adder, two multiplier, stator current conversion unit, stator phase current sensor, output connected to control input of stator current conversion unit, input for reference signals of which is connected to stator phase voltage sensor output, p The first and second outputs of the stator current conversion unit are connected to the first inputs of the first and second multipliers, the second inputs of which are connected to the first and second outputs of the magnetic flux conversion unit, and the codes of the multipliers connected to the second integrator's output to the third controlled input stator frequency converter, first input frequency 1g and magnetizing current IQ  i + i in order to ensure the constancy of the resulting magnetic flux in the air gap of the machine (Ф over the horizon in accordance with a predetermined value of ". In addition, the electric drive has a system to maintain the orthogonality of the current vector cores and the resultant magnetic flux. The orthogonality condition of the current vector cores and the resultant magnetic flux is performed in case of equality of the scalar product 1,. F O, or; -, in the coordinates X, Y 1уФ8х- - О-. Output signals from sensor A of stator phase currents are transformed using the block 5 transformations of stator currents into zero frequency components iy, iu, presented in axes X, Y, rotating synchronously with the field of the motor To multipliers 18 and 19, output signals from the magnetic flux conversion unit 10 are received, representing the components of zero frequency Φ & x Ts currents i, in. The multipliers 18 and IV multiply the same components of the flux Φ and the current i, after which the signal is summed by the first adder 20 and through the astatic controller 21, made in the form of an integrator, goes to the third control five 0 five j Invention Formula 1o A method of controlling a dual power motor made on the basis of an asynchronous motor with a phase rotor according to aut. No. 1515323, characterized in that, in order to increase efficiency by reducing losses in stator steel, after changing the alternation of the phases of the rotor winding of the frequency of the currents in the stator and rotor windings set equal. 2o A device for controlling a dual-power motor, made on the basis of an asynchronous motor with a phase-rotor, autorum No. 1515323, characterized in that a third arithmetic unit, a frequency comparator, a controlled analog switch, a second integrator, a second adder, two multiplier, stator current conversion unit, stator phase current sensor, output connected to control input of stator current conversion unit, input for reference signals of which is connected to stator phase voltage sensor output, p The first and second outputs of the stator current conversion unit are connected to the first inputs of the first and second multipliers, the second inputs of which are connected to the first and second outputs of the magnetic flux conversion unit, and the codes of the multipliers connected to the second integrator's output to the third controlled input stator frequency converter, first frequency input 0 A comparator is connected to the corresponding output of the first arithmetic unit, the second input is connected to the corresponding output of the set-. generator of a two-phase harmonic signal, while between a pair of outputs of the second arithmetic unit and a pair of inputs of the block of the inverse coordinate transformation are included Fig: 2 hence the controlled analog switch and the third arithmetic unit, the other pair of inputs of which is connected to the outputs of the first arithmetic unit, and the control input of the controlled analog switch are connected to the output of the frequency comparator. Torah.