Design And Research On The Novel Excitation Regulator Based On Chopped Wave Control

In electric power system operation, we need to maintain the generator terminal voltage and ensure the stability of synchronous generator operation, which is the principle requirement of ensuring power system security and economic operation. Synchronous generator excitation control system is an important component in electric power system control, and it plays an important role in reducing voltage fluctuations, balancing of reactive power allocation, improving immunity, maintaining stability of the system and so on. So it is of great significance to study magnetization control.Firstly, this paper takes ITSE index of extreme voltage step response curves as the optimization index, uses SIMULINK platform to compute the fitness function, and makes use of MATLAB genetic algorithm toolbox to optimize PID parameters of magnetization system. And then prove its effectiveness by examples.Secondly, this paper makes a deep study of chopped wave control and designs a new digital excitation regulator on the basis of the popular-used self-shunt excitation system. In this design, the terminal voltage of generator is firstly rectified by an uncontrollable rectifier to DC voltage, and then controlled by changing IGBT's duty cycle of the chopper circuit. This controllable DC voltage provides field current for field winding which makes the terminal voltage of generator controllable.Finally, using LM3S818 processor as the control core, we program every function of excitation control system in IAR Embedded Workbench and debug them with hardware circuit. By analyzing the records of debugging, we verify the effectiveness of this design.The most important advantage of this device is that it releases the requirement of strict time sequence in phase control of traditional thyristors. And the drawback is that the output power of excitation system is limited by IGBT power limits. But distributed power system is so popular right now that the study of small and medium excitation device is of great practical significance.