Research On The Integragration Of Asynchronous Motor And Load Emulator

Normally,in the testing progress of a motor driver for performance and assessment,a scheme of “ motor +mechanical load ” was adopt.There are some disadvantages in this scheme,including that the program is not enough comprehensive and the adjustment of parameter is not flexible.In this dissertation,a motor simulator system based on inverter is designed to simulate the characteristics of asynchronous motor and its associated mechanical load.It can replace the actual motor and load test platform.The system is convenient for the tests of frequency conversion driving and provides guidance for control optimization.In order to simulate the motor port voltage and current characteristic,according to the different mathematical model of motor,a VTC model and a CTV model of motor emulator systems have been established.Specifically,the main work of this paper is as follows:(1)Establishment of dynamic mathematical model of asynchronous motor.In order to facilitate the calculation of the motor emulator,a mathematical model of the equation of state is established in the two-phase stationary coordinate system;Aiming at the realtime solution of the mathematical model of the motor,the difference equation of the motor model is established,and the calculation accuracy of several numerical methods under different synchronization steps is compared and analyzed.(2)Research on control technology of motor emulator with VTC mode.As a result of the port voltage waveform arbitrary,and it is difficult to design a phase lock loop,a current closed-loop control strategy based on virtual rotor flux orientation is proposed;the influence of motor emulator with several different interface circuits on the port current characteristics is compared and analyzed;the scheme of the proposed motor emulator is simulated under several typical working conditions;the measurement method of the square wave power supply voltage is studied,and the simulation of the motor emulator is carried out under the square wave power input.(3)Research on control technology of motor emulator with VTC mode.A mathematical model of motor with stator current as input is deduced and built,and a motor emulator of CTV mode is constructed according to this mathematical model;the operation of motor emulator of CTV model under several typical working conditions is simulated and analyzed;the port characteristics and the speed characteristics of motor emulator is studied when a square wave power as input,and analyzes the relationship of switching frequency between the power side and the simulator side.