励磁调差单元对发电机频率响应特性的影响分析

摘要

发电机的频率响应特性是电力系统稳定器的参数整定的重要依据,为优化参数整定,维护电力系统安全稳定运行,对引入调差单元的发电机的频率响应特性进行研究.通过分析负载电流极性、调差系数及调差极性改变时励磁系统测量电压的变化特性,采用戴维南电路对自动励磁的作用进行等效研究,并对不同调差方式下发电机的频率响应特性进行了仿真实验.理论分析与仿真结果表明,调差单元引入后测量电压的改变会影响同一频率下发电机机端电压的幅值和相位,且调差单元在低频段对发电机频率响应特性的影响较为明显,因此具有一定的工程应用价值.%The frequency response characteristic of the generator is important for parameters setting of power system stabilizer (PSS).In order to optimize parameters of PSS and maintain grid's safe and stable operation,frequency response characteristics of the generator which is introduced load compensation system are studied.Through analyzing the changing characteristics of measured voltage of excitation system as the change of the polarity of load current,load compensation coefficient and the polarity of load compensation,the effect of excitation system is studied by using Thevenin's equivalent circuit,and the frequency response characteristics under different compensation methods are simulated.The theoretical analysis and simulation results show that the change of measured voltage of excitation system will affect the amplitude value and phase of the generator's terminal voltage at the same frequency,and the influence of additional compensation on generator's frequency response characteristics at low-frequency band is obvious.It has certain engineering application value.