Adaptive Ant Colony Optimal Design Of Generator Excitation Controller And Study Of PSS

In the power system, keeping the Voltage, guaranteeing the stable operation of the synchronous generator both are basic requirements of safe and economical operation of the power system. Synchronous generator excitation control system is one of the most important parts of power system. It can reduce the fluctuation of the voltage, balance the distribution of inactive power, increase anti-interference and stable operation of the system.Controlling the excitation system properly by the principles of automatic control and optimization theory is very important to build a power system with good dynamic quality and stability. Especially, comparing to other methods, it is more effective and economical. Therefore, the optimization of synchronous generator excitation control system has decisive effect to overall power system and the new research is highly valuable in the application.Based on the ant colony theory and characters of the power system, this paper improved the basic ant colony algorithm which is used in the excitation controller, utilize adaptive ant colony algorithm to design excitation system controller, finish a program for the adaptive colony algorithm.Adaptive ant colony algorithm is more independent to the PID values got by the Z-N method, it abtains balance between quick-convergence and stay, controller based on this controls the voltage more exquisitely.Simulation of one machine—infinite system is programmed as three different conditions,they are no-load generator, the voltage disturbance and short-circuit fault. Through comparing the voltage of generator which is controlled separately by traditional controller, controller with basic ant colony algorithm and controller with adaptive ant colony algorithm under each condition, we can draw the conclusion that the last controller is independent to the math model of the object and project experience, simple and practical, additionally, it controls the voltage as smaller errors, it is also able to control the system as good as before when the generator operates in the deviating point.The relationship between exitation system and low frequency oscillation of power system is analyzed. One machine—infinite system model is built in MATLAB environment. Small disturbance and short-circuit fault occurred separately in the simulation. Under each condition, compare the Pe curve of generator with heavy load and light load, it indicates that when the generator is with heavy load and controlled by high-times and quick-action excitation system, damp character and the ability to reduce the oscillation of it turns bad. To reduce the oscillation, this paper studied the principle of the power system stabilizer (PSS), set proper parameters of it and add it to the excitation system. Then, simulation is executed again in the same oscillation. Pe curve shows that oscillation is stopped quickly. The result demonstrates that PSS is important and effective to restrain oscillation.