基于MATALAB的百万千瓦发电机灭磁仿真计算

The simulation computation of de-excitation for megaton generator based on MATLAB

发电机灭磁是发电机发生故障时消除故障防止事故扩大的最后防线,发电机的安全、可靠和快速的灭磁能力直接决定了发电机等设备的安全水平.本文对同步发电机在空载状态下的三类常用的灭磁方式进行了研究,它计及了转子阻尼绕组的效应,利用了同步发电机在d,q轴的Park方程,特别是利用分析表达式表示同步发电机的空载特性,从而计及其饱和的影响.在用MAT-LAB/Simulink仿真中利用了积分器解联立微分方程组的方法,对1 000MW汽轮发电机空载灭磁,作了空载线性灭磁方式的仿真计算,得到了预期的结果,相关结果对于百万千瓦发电机灭磁系统的设计具有指导意义.

The de-excitation is the last protection line for the generator when it＇s broken- down. The reliable and quick de-excitation ability dominates the safety level of the gen- erator. In this paper the three conventional de-excitation methods for the synchronous generator in unload condition are studied, the effect of damping winding is considered and Park equations in d,q axis are used. Specially, no-load characteristic （NLC） of gen- erator is represented by analysis expression, so the effect of saturation of NLC on de-ex- citation is included. Differential equation group is successfully solved with integrators in MATLAB simulation. Finally, an example of de-excitation for a 1000 MW synchronous generator on no-load with linear de-excitation methods is given. The result has practical guidance for the de-excitation system design.