Research And Design Of Digital Excitation System For The Synchronous Generator Based On DSP

The scale of power network is more and more large, and the requirement to the reliability of power system and the quality of electrical power is more and more high. One of economical and effectual methods is to improve the performance of excitation system of synchronous generator, which can ensure stability of generator and power system. For large generator, adjustment of excitation system can improve the performance of generator and power system. When the large disturbance happens, the undulation of net voltage can be decreased, the superfluous energy of generator can be taken out, the renewal of voltage can be quickened. The generator is a non-linear, multi-variable system, so non-linear control should be adopted, which embodies the essence of generator, in order to achieve excellent performance. For small generator, adjusting excitation system after malfunction has less effect on maintaining the voltage and stability of system, but plays a good part in adjusting the reactive power or power factor of generator after generator is connected grid.In view of the reliability and feasibility, self-parallel excitation system with thyristors is adopted, controlling method is excitation current and power factor double-loop PID control, i.e. excitation current loop is working, making the generator to be connected grid, and power factor loop is added after generator is connected grid in order to adjust the power factor. Derivate feedback is adopted to decrease the overshoot.The control chip of system is TMS320F2812 DSP, which has high frequency, low power waste, high performance 32-bit CPU, 128K Flash, 18K RAM, 12-bit precision AD converter, 16-channel PWM, EV, SCI, SPI, eCAN, MCBSP, XINTF and so on. The high performance of peripheral device can simplify the circuit, improving the reliability of system.So as to simplify the calculation, DC sampling is adopted, and the sampling period is 0.002s. The set value of power factor is 0.8. After generator is connected grid, excitation current loop is internal loop, and power factor loop is external one. And then, C language is adopted by the program, because of the readability and the transplantability.This article indicates the simulation waves, the schematic circuit diagram, the...