Research On Comparison Of Characteristics Between Rotor And Stator Side Based On Six-wave Double-variables Cycloconverter

Based on six-wave double-variable theory, adopting theory analysis,simulation andexperiment methods,the article analysed and comparatively researched the frequencyconversion characteristics between the rotor and stator side. First of all,the dynamicmathematical model and steady-state equivalent circuit model of wound motor isdeduced when the power-supply is in the stator and rotor side, on this basis, theexpression of electromagnetic torque and efficiency based on V/F(voltage/frequency)control with constant torque load is obtained, the mechanical characteristics underdifferent frequency and efficiency characterstics based on V/F control are analyzed andcompared; Then, with the aid of the Matlab/simulink software, the system simulationmodel is set up, focusing simulation analysis and comparison on the power waveform,the starting up process, mechanical properties and speed-adjusted properties betweenthe stator-side and rotor-side variable frequency;Finally, the system experimentalplatform is established, the experimental results of the output voltage and currentwaveform, mechanical properties, efficiency properties and speed-adjustedperformance are validated,contrasted and analyzed between the stator-side androtor-side variable frequency. Theory, simulation and experimental results show thatthe experiment waveform of rotor-side variable frequency is poor,there exsists somedifference between the experimental results and theory or simulation.This is becauserotor-side variable frequency power supply mode is change, the impedance ofstator-side and rotor-side is different, and double variable control have specialrequirements on waveform symmetry and trigger control.so the pulse triggeringcontrol strategy remains to be further improved in rotor side.The results show that the differences of waveform symmetry and trigger controlstrategy between stator-side and rotor-side variable frequency due to the differences ofmotor impedance parameters in the stator and rotor side;all the differences ultimatelyresults in the differences of start torque, maximum torque and critical slip betweenstator-side and rotor-side.The overall results show that the rotor-side variablefrequency provides a reference for the scheme of low voltage control high-voltagemotors,and also the basis of double-fed speed regulation,it has a certain application prospects in the industry.