Designed Excitation System For Synchronous Motor Based On FPGA

Synchronous motor which had the advantages of good stability, strongoverload-capacity, high efficiency and large capacity, has been used widely in manyfields. for example, petroleum, chemical, coal, metallurgy, electric power, waterconservancy, city water supply, gas supply et. Therefore, synchronous motor marketdemand is also very great.As the most important part of the synchronous motor, excitation device whosefunctions mainly include the following three points:(a) In the process of synchronousmotor starting on the asynchronous state, synchronous motor is brought into thesynchronous state;(b) On the synchronous operating of synchronous motor, it cancontrol the excitation current;(c) In the process of synchronous motor running,excitation device always diagnosis system faults to ensure the safety and stability ofsynchronous motor.Based on the detailed analysis of the synchronous motor excitation device, thepaper introduced a new design scheme of the excitation device for synchronous motor,which chose the FPGA chip of reprogrammable, high speed, high integration and highreliability as the core of excitation controller. The design scheme used Verylog HDLas the programming language, Modelsim SE6.5as the simulation tool to achieve thesynchronous motor automatic full voltage excitation, inverter and demagnetizationfunctions. In addition, the excitation device had two ways of working, for exampleopen loop and closed loop, in order to complete synchronous motor constant angular,constant current, constant power controlling and other functions. The whole systemdesign scheme, which hardware circuit is simple, high reliability, debugging andrepairing easily. The practice proved that the design scheme was not only feasible, butalso efficiency and stability higher than existing excitation device.