Microcomputer-based Excitation Control For Small Synchronous Generator

The load always changes when the generator is running on the normal condition, and different load with different capacity has different generator's excitation magnetic field and different internal resistance voltage drop of synchronous generator for their various power factor. To keep the terminal voltage stability of the synchronous generator, the synchronous generator excitation current must be regulated according to the size and the nature of the load, so it is of great value to study the excitation controller of synchronous generator.This thesis takes the single-chip as the core of control and the fuzzy self-adaptive PID controller as the main control method, and transforms the excitation-conditioning system relied on the existed analog circuits to realize all kinds of functions into digital excitation-conditioning systems. Firstly, the development of synchronous generator excitation controller is introduced, and the characteristics and the existed problems of synchronous generator excitation controller are analyzied. Secondly, a brief introduction of the selected MCS-51 series single-chip is given, in the way of adopting modular design principle and specific analyzing synchronous excitation controller hardware and software, and the system hardware and software flow chart are obtained. Finallly, combined with the external circuit, many functions have realized such as analog sampling, the DC signal transforming, analog-to-digital conversion, frequency measurements, phase-shifted and excitation trigger control algorithms. A variety of anti-noise measures have taken for hardware and software, and this can improve the performance of excitation controller.Experimental results have shown that the patrick static excitation controller with a fuzzy self-adaptive correct function has simple and reliable hardware, cost-effective, and can widely be applied to a variety of synchronous generator excitation control, especially for the small generator. It will have excellent generalized appllication avenue.