计及调速/励磁系统的同步发电机等效惯量辨识

Identification of Equivalent Inertia of SG with Governor and Excitation Systems

对同步发电机的惯量辨识是电力系统功角/频率稳定分析的基础。本文提出利用二阶转子运动方程辨识高阶同步发电机模型等效惯量的方法。首先,提出含机电暂态、励磁、调速的同步发电机等效惯量辨识模型;其次,提出基于受控自回归滑动平均模型和可变遗忘因子最小二乘法的等效惯量辨识算法;最后,仿真比较等效前后同步发电机动态响应,验证了所提算法的准确性。结果表明,计及励磁和调速系统后,同步发电机等效惯量呈衰减趋势,故障初期大于转子惯量H,稳态值小于H。

The identification of the inertia of a synchronous generator is a basis for the analysis of power system angular/frequency stability.In this paper,a method to identify the equivalent inertia of a high-order SG using the 2nd-order mo-tion equation of rotor is proposed.First,an identification model of the equivalent inertia of SG is put forward,which in-cludes the electro-mechanical transient,an excitation system,and a governor system.Then,an identification algorithm based on the controlled autoregressive moving average model and the variable forgetting factor least square method is de-rived.Finally,the dynamic responses of SG before and after the equivalence are compared through simulations,thus verifying the accuracy of the proposed method.It is found that with the excitation and governor systems,the equivalent inertia of SG decays with time.The initial value of equivalent inertia under fault is larger than the rotor inertia H,while the steady-state value is less than H.