DSP Based Simulation, Testing And Control For Excitation Systems Of Synchronous Generators

The performance of the excitation controller directly influences the generator's safe operation and the stability of the electric power system. It can be tested by the closed loop of the excitation controller and the synchronous generator. Therefore it is useful to get the performance of excitation systems with the real-time simulation of the synchronous generator.After analysis and comparison, a kind of digital signal processor (DSP) TMS320C32 based instrument for simulation and testing of synchronous generator excitation system is proposed. The real-time simulation of synchronous generator and the testing of the excitation controller are integrated in one instrument, and the performance of excitation controller can be tested without synchronous generator.The mathematic models for every part of the excitation systems are derived firstly, and the research and development of the system consisting of the upper computer and DSP part is respectively described.The data acquisition and simulation of the system is made up of TMS320C32 and peripheral circuit, which is developed by C language and assemble language. Its central functions are data acquisition and simulation. With digital filter, Fast Fourier Transform Algorithm (FFT) and some other algorithms, the data collected are flexibly processed. The real-time simulation is realized in DSP. The upper computer of the system is made of Personal Computer (PC), which is developed by C++ Builder 6.0. It manages the testing. PC and DSP can exchange data each other through RS-232C serial communication. Field experiments demonstrate that the excitation systems can be well simulated and measured with the proposed system, and the burden of testing engineers is freed.With the fast development of electric power systems, their stability has become increasingly challenged. Improving the excitation control of the synchronous generator is an effective way to increase the stability level of a power system and guarantee power supply. The proportional and integral (PI) + Power System Stabilizer (PSS) controller is mostly used in excitation systems today. The linear optimal excitation controller?(LOEC) is mostly studied in excitation systems, and has been used in some plants, but it needs to be more improved in practice. The two control strategies are simulated and compared in this paper under the environment of SIMULINK of MATLAB. Their advantage and disadvantage are analyzed.