SU1332427A1 - Electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in rowing electrical installations of icebreakers, in a traction drive. The aim of the invention is to increase the overload capacity of the electret-drive. This goal is achieved by introducing into the electric drive the Hall electromotive force sensor 15, integrator 16, quadrants 17, 18, adder 19, comparison unit 20, setpoint generator 21 of the amplitude of U) with i i F i &

Description

magnetic flux and block 22 magnetic flux transformations. The sensor 15 is installed in the air gap of the asynchronous motor (BP) 1 with a phase rotor. In the electric drive, due to the introduction of these blocks, the orthogonality of the stator current vectors and the resulting magnetic flux of the air gap HELL 1 is controlled.

The invention relates to electrical engineering, in particular to controlled electric drives based on asynchronous motors with a phase-rotor, and can be used, for example, in electric propulsion systems for icebreakers, in a traction electric drive where a large overload torque condition is possible and requires deep speed control.

The purpose of the invention is to increase the overload capacity of the electric drive by maintaining the orthogonality of the resulting core current vectors and the magnetic flux of the air gap.

Figure 1 shows the functional diagram of the drive; 2 is a vector diagram for an asynchronous motor with a phase-rotor.

The electric drive contains an asynchronous motor 1 (Fig. 1) with a phase rotor, the stator and rotor windings of which are connected respectively to the outputs of the converter 2 stator frequency and converter 3 rotor frequencies, each of which is made with three control inputs, sensors 4 phase stator currents connected outputs to control inputs of stator current conversion unit 5 sensors 6 stator phase voltages connected by outputs to inputs for reference signals of block 5 stator current conversions and sensor inputs, 7 frequencies shackles stator, whose output is connected to a second control input of the inverter 2 of the stator frequency, the blocks 8 and 9 assignments

BP at a given stator current of AD 1 and the resulting magnetic flux in the air gap of AD 1 or the minimum stator current is provided for a given load on the shaft of AD 1 and the set value of the magnetic flux. The latter leads to a reduction in electrical losses in the windings of the stator HELL 1 and the thyristors of the frequency converter 2. 2 Il.

the amplitudes of the stator and rotor voltages connected by the outputs to the first control inputs of the converters 2 and 3 of the stator and rotor frequencies, respectively, the unit 10 of the tasks of the constant frequency of the rotor currents connected by the output to the second control input of the rotor frequency 3,

multiplier 11, the first input of which is connected to the first output of the stator current conversion unit 5, multiplier 12, the first input of which is connected to the second output of the stator current conversion unit 5, and the outputs of the multipliers 11 and 12 are connected to the inputs of the first adder 13, the output of which is connected to the input the first integrator 14 connected to the output

the third control input of the converter 2 stator frequency,

An electromotive force sensor Hall 15 is inserted in the electric drive; it is installed in the air gap of an induction motor with

a phase rotor, a second integrator 16, quadrants 17 and 18, a second adder 19, a comparison unit 20, a magnetic flux amplitude setting device 21 and a magnetic flux conversion unit 22

air gap whose entrances

connected to the outputs of the EMF sensor Hall 15 and to the outputs of the sensor 6 phase stator voltages, and outputs to the inputs of quadrants 17 and 18, the outputs of which are connected to the inputs of the second adder 19 connected by an output to the input of the comparison unit 20, to another input of which is connected knob 21 magnetic flux amplitudes,

The output of the block 20 comparison

16 connected by the output to the third control input of the converter 3 of the rotor frequency.

The drive works as follows.

The speed of rotation is controlled in two channels.

The first channel (the Hall root control 15, proportional to the magnitude) unit 8 sets the amplitudes of the magnetic fluxes to us, P,. the stator voltage acts on the air gap on the phase axes and on the control phase of the rectifier starter of the stator (or F and Pa on two, on the frequency converter 2 of the stator and thereby regulates its output voltage. On the second channel (excitation control ) block 9 sets the amplitude of the rotor voltage across the stator), is converted by block 15 converting magnetic fluxes into components rjj ,,, 5 zero frequencies, represented in axes x and y, synchronously rotating

determines the amplitude of the output eg - with the engine field. After the transmitter is mounted, frequency 3 of the pth-2o square of the magnetic components

ra.

When supply voltage is applied to

stator frequency converters 2 and

 rotor 3 block 10 set a constant

the frequency of the rotor current (sets a constant flow (P in the air gap frequency of about 3-5 Hz) opens the controlled valves (thyristors)

flow to the quadrants 17 and 18 and the sum of them in the second adder 1 is the input signal from the last one, which is proportional to the square of the amplitude of the magnet

engine 1, is fed to the input of the unit 20 comparison. On the other entrance the last

it receives a signal from the unit 21 of the amplitude of the magnetic flux

Eal

Converter 3 of the rotor frequency and winding of the rotor of the induction motor 1 begins to flow three-phase air gap of the engine. From the output low-frequency excitation current, and from the comparator block 20, the signal produces a rotating magnetic field. when the rotor of the asynchronous regulator 16, made in the motor 1 is fixed, then the sensor transforms the frequency of the stator current connected to the sensor 6 to the transformer converter 3 frequency of the rotor (per stator frequency 2 of the stator (on the control - the input of its rectifying element) and

so changes the magnitude of the excitation voltage of the bias voltage + D (J (, and is fed to the third control input

. Leading Inventor Input) is received. control signals with rotor power frequency co. opening controllable valves. In this case, a three-phase current flows on the stator winding of the asynchronous motor 1 and creates

 a rotating magnetic field that, when rotated in the same direction and at the same speed, interacts with the rotor field with it, creating a torque. When the latter exceeds the moment of load resistance, the rotor of the induction motor 1 will begin to rotate.

From the output of the sensor 7, the frequency of the stator currents is removed after this signal

40 Deni 1

magnetized current ..

45

in order to ensure the constancy of the resulting magnetic flux in c) the sound gap of the machine fL / 1 const in

oh oh

according to a given value. At the same time, the output signals from the sensor 4 phase stator currents are converted using a block 3 of stator current conversions into components of zero frequency i, i,., Represented in axes X and y. The output signals from the block 22 of magnetic flux transformations, which are the components of zero frequency P .f r, and the currents ij |, 1, are fed to multipliers 11 and 12, which multiply by one 50

according to a given value. At the same time, the output signals from the sensor 4 phase stator currents are transformed with the help of block 3 stator current conversions into components of zero frequency i, i,., Represented in axes X and y. The output signals from the block 22 of magnetic flux transformations, which are the components of the zero frequency P .f r, and the currents ij |, 1, are fed to the multipliers 1 and 12, which multiply by

with a frequency equal to the sum or difference of the frequencies of rotation with and feeding the roto-nominal components of the flow pa Q, i.e. U, (1) current i, and thus output

arriving at the control input of the transducer 11, receive Pjn k on the generator of the stator frequency 2 and providing the output of the multiplier 12 iu.

nor the magnetic fields of the stator and the rotor.

In case of heavy starts or overloads of the engine, the system of limiting the ultimate magnetic flux in its air gap is activated. The output signals from the Hall sensor 15 are proportional to the magnitudes of the magnetic fluxes, P,. the air gap on the axes of the phases of the stator windings (or F and Pa - on two,

axis of the stator) are transformed with the help of the block 22 of the transformations of magnetic fluxes into the components rjj ,,, 5 zero frequencies, represented in axes X and y, which are synchronously rotating

flow rate (P in the air gap

to the quadrants 17 and 18 and the sum of them in the second adder 19, the input signal from the last is proportional to the square of the amplitude of the magnetic flux (P in the air gap

engine 1, is fed to the input of the unit 20 comparison. To the other input of the latter receives a signal from the unit 21 of the amplitude of the magnetic flux

Eal

 air gap of the engine. From the output of the comparison unit 20, the resynchronous signal +, using an astatic controller 16, made in the form of an integrator, is converted into frequency converter 3 of the rotor (to the input of its rectifier unit) and

bias voltage signal + D (J (, and is fed to the third control input

0 Deni 1

magnetized current ..

five

in order to ensure the constancy of the resulting magnetic flux in c) the sound gap of the machine fL / 1 const in

oh oh

according to a given value. At the same time, the output signals from the sensor 4 phase stator currents are converted using a block 3 of stator current conversions into components of zero frequency i, i,., Represented in axes X and y. The output signals from block 22 of magnetic flux transformations, which are the components of zero frequency P .f r, and the currents ij |, 1, are fed to multipliers 11 and 12, which multiply by one

 the components of the current flow i, and thus the output

In an electric motor with an asynchronous motor with a phase rotor, the orthogonality of the stator current vectors and the resulting magnetic flux of the air gap of the motor (Fig. 2) are monitored, which is performed under the condition that the scalar product equals zero .0 or in the coordinates (x, y):

.R(

+ 1,

S, 0.

(2)

 at 1 of

The condition obtained is implemented using an adder 13 and an astatic controller 14, which is designed as an integrator, the output from which, if not fulfilled (2), goes to the control input of the stator frequency converter 2 (to the control input of the inverter) and determines the phase offset of the control pulses until the condition (2) is orthogonal to the current and flow vectors. When this is achieved, the maximum value of the electromagnetic torque of the engine, d | P I at given values of current I of the stator and the resulting magnetic flux Pf- in its air gap. Or, at a given load on the shaft and a given value of the magnetic flux, the minimum stator current and, consequently, the minimum electrical losses in the stator windings and the thyristors of the converter 2 of the stator frequency are provided.

An asynchronous motor with a phase-wound rotor in an electric drive has the properties and characteristics of a compensated DC motor with independent or compound excitation. At the same time, the brushless vent machine is characterized by a high frequency ratio of wax and maximum torque, dynamic stability, high energy performance, the ability to control the rotational speed throughout the whole range of motor and generator operation.

Compared to a DC motor based on a synchronous machine, an asynchronous motor with a phase-rotor provides for switching the current in the core winding with the excitation frequency when the rotor is stationary - in the stop mode. The latter allows to reduce the installed power of the main converter - transform

2427

the bodies of the engine and the engine itself, working under conditions of the re-start-up jack. It is important

for traction drive and comb

icebreaker type electric motor drive.

Thus, the introduction of a Hall EMF sensor, an additional integrator and adder, two quadrs, a comparison unit, an amplitude setting unit, a magnetic flux and a magnetic flux conversion unit into the electric drive determines the orthogonality of the resulting current vectors in the asynchronous phase-rotor motor the core and the magnetic flux of the air gap, due to which, in comparison with the known solution, the overload capacity of the electric drive is increased.

Claims (1)

Invention Formula five 0 five 0 An electric drive containing an asynchronous motor with a phase rotor, the stator and rotor windings of which are connected respectively to the outputs of the stator and rotor frequency converters, each of which is made with three control inputs, sensors of phase stator currents connected by the outputs to the control inputs of the block transformations of stator currents made with two outputs, sensors of stator phase voltages connected by outputs to the inputs of the reference signals of the stator currents conversion unit and to the inputs of the sensor of current frequency st torus, blocks of setting the stator and rotor voltage amplitudes, connected to the first control inputs of the stator and g rotor frequency converters, outputs of the constant frequency of the rotor current, connected to the second control input of the rotor frequency converter, two multipliers, first inputs which are connected respectively with the first and second outputs of the stator current conversion unit, and the outputs of the multipliers are connected to the inputs of the first adder, the output of which is connected to the input of the first integrator connected to the output of the third control input of the stator frequency converter, characterized in that, in order to increase the overload method 0 five In order to maintain the orthogonality of the resulting core current and magnetic flux air gap vector current in an induction motor with a phase rotor, the Hall EMF sensor installed in the air gap of an induction motor with a phase rotor, a second integrator, two quadrants, a second adder, a comparison unit, a magnitude setting generator, was introduced. flow and a unit for converting the magnetic flux of the air gap, whose inputs are connected to the outputs of the EMF sensor Hall and to the outputs of the sensor the stator phase voltages, and the outputs - to the second inputs of two multipliers and to the inputs of two quadrants, the outputs of which are connected to the inputs of the second adder connected to the output of one input of the comparator unit, to the other input of which the output of the magnetic flux amplitude is connected, the output The comparator unit is connected to the input of the second integrator connected to the third control input of the rotor frequency converter by the output. Iff FIG. 2