The Research On Governor Control Characteristics Of Doubly-fed Variable Frequency Continuously Based On Bi-variants Cyclo Converter

Previous speed control system used the look-up table method output pulse triggering of thyristor, switching frequency under the limited frequency band only,frequency range is larger, so speed smoothness and Governing continuity is poor.This paper uses real-time algorithm of online and continuous variable frequency control strategy, refine the frequency range, Optimizing the software realization of the inverter switch, greatly improving the double fed motor smoothness and stability of the Variable frequency switching process.Firstly, according to the general Cosine Wave Crossing Method, using the relative coordinates derived the online real-time calculation method of trigger time constant and the control word. Then according to the double variable cyclo converter principle,respectively control the trigger pulse front edge and the rear edge, then propose Continuous variable frequency speed regulation control strategy. Then, In the matlab environment doubly-fed variable frequency speed regulation system model is established, Through simulation research of The asynchronous motor doubly-fed starting experiment, Different rotor voltage and commutation angle,load to The influence of doubly-fed starting and Doubly-fed motor continuous variable frequency speed-governing experiment, validate the feasibility,correctness of real-time algorithm and control strategy. Finally, based on the optimization of The experiment method,control circuit design and software implementation, study the asynchronous motor Doubly-fed starting experiment and Continuous variable frequency speed-governing experiment.Research results show that, in the simulation experiment and motor experiment,selecting Select the appropriate feed-in parameters under different The starting conditions, asynchronous motor can smoothly to pull in the double feed starting; the frequency range is accomplished enough refinement of the case,the motor can realize continuous variable frequency speed smoothly in statistical sense.