SU781622A2 - Apparatus for measuring electromagnetic moment of induction motor - Google Patents

Description

one

The invention relates to measurement technology and can be used in automated drive control systems.

In principle, a device for measuring the electromagnetic moment of asynchronous motors is known, which contains two current and flux multipliers Phases, the outputs of which are connected in series to each other, two identical blocks of simulation of the magnetic flux of the phase between the voltage sources and the current the phases of the induction motor and the inputs of the corresponding multiplying devices, and the amplifier, the simulation unit being designed as an integrator and a voltage transformer with a load potentiometer Lines connected in series and counter-active resistance and inductance, which are connected to the secondary winding of the current transformer, and the output. the latter is connected to the input of the integrator l.

The drawback of the device is the low measurement accuracy due to the use of integrators in the modeling units.

The purpose of the invention is to improve the measurement accuracy.

 it is reached that each block of modeling the magnetic flux of the phase is equipped with an additional transformer, the primary winding of which is connected parallel to the load potentiometer, resistance and input, and the secondary is connected in series with the corresponding secondary winding of the transformer of the additionally introduced third unit of 1515 and connected to input of the corresponding multiplying device, and other inputs of the multiplying devices are inductively coupled to the first and modeling blocks.

The drawing shows the principle20. A full block diagram of the proposed device.

A device for measuring the electromagnetic moment of asynchronous motors contains three identical blocks 1 of physical simulation of the phase-linking phase, two multiplying devices based on Hall EMF sensors 2 and an amplifier 3. The modeling unit is designed as a trans-30

voltage formatter 4, which potentially isolates the power circuit and measurement circuit: h, and current transformer 5, in parallel with the output of which are connected successively connected elements 6 and 7 ,. simulating the resistance and inductance of the stator phase dissipation of an induction motor. Elements 6 and 7 are also connected in series with a divider tensioned on a potentiometer 8. Element 7 is bd1n6vrehmno and the excitation winding of the magnetic circuit of the multiplying device fed from the current source of the current transformer 5. In parallel with elements 6-8, the primary winding of an additional transformer is connected, 9, and the secondary windings of the transformers of the first two modeling units are connected in series with the corresponding secondary windings of the additional third modeling unit and connected to the current inputs of the respective multiplying devices 2.

The device works as follows.

The phase voltages and currents of the stator of the induction motor are supplied to the transformers 4 and 5 of the voltage and current of the magnetic flux simulation units. From the output of the transformer 4, the linear voltage is applied to the potentiometer 8, which is used to establish the required division factor. This voltage is then summed algebraically with the voltage across the 6.7 elements generated by the stator phase current. The resulting voltage, proportional to the emf of the phase, is applied to the primary winding of the transformers 9.

the secondary windings are summed up by a series-opposite connection in such a way that the resulting voltage is ahead of the phase emf by IV / ZjT.e. corresponds to the direction of the vector of the magnetic flux phase. This 5 voltage is applied to the circuit.

control element of the Hall 2, located in the gap of the magnetic circuit of the element 7. The difference of the output voltages of the multiplying devices 2 is fed to the input of the amplifier 3, the output

the voltage of which will be proportional to the magnitude of the electromagnetic torque of the asynchronous motor.

Claims (1)

Invention Formula A device for measuring the electromagnetic torque of asynchronous motor drives according to bus No. 492764, characterized in that, in order to improve the measurement accuracy, each unit for modeling the magnetic flux of a phase is provided with an additional transformer, the primary winding 5 of which is connected in parallel with the load potentiometer, resistance and inductance, and the secondary is connected in series with the corresponding secondary winding of the transformer of the additionally introduced third modeling unit and connected to the current input of the corresponding multiplying device, and others The 5 inputs of multiplying devices are inductively coupled to the first and second modeling blocks. Sources of information taken into account in the examination 1. USSR author's certificate 1 492764, class G 01 L 3/00, 1974. "four 781622