计及紧急直流功率支援的扰动后稳态频率预测算法

提出了一种计及紧急直流功率支援情况下,能同时考虑直流两侧电网频率响应的扰动后稳态频率预测算法。该算法对系统发电机调速器方程、负荷静态模型方程、直流输电系统传输功率方程和系统网络方程进行了线性化处理,同时考虑紧急直流功率支援,推导了两区域交直流系统扰动后稳态频率预测方程,可以直接快速地计算出扰动后各区域的稳态频率和使其中一个区域稳态频率恢复到设定值时的直流功率支援量。对一个典型的两区域交直流并联系统进行了仿真分析,仿真结果表明所提算法具有较高的精度和较快的计算速度,证明了算法的适用性和有效性,具有与紧急频率控制相配合并在线应用的前景。

Prediction Algorithm of Steady Frequency After Disturbances Considering Emergency DC Power Support

A prediction algorithm of steady frequency after disturbances for AC/DC hybrid power grid is proposed, which takes into consideration the emergency DC power support(EDCPS)and the frequency response of the AC systems on both sides of the DC link. With the linearization of the generator governor equation, the static load model equation, the transmission power equation of DC transmission system, and the network equation of power system, the prediction equation of steady frequency after disturbances in a two-area AC/DC hybrid transmission system is derived by taking EDCPS into consideration. The steady frequency after disturbances in every area of the two-area AC/DC hybrid transmission systems can be quickly and directly calculated, so that the amount of DC power support will make the steady frequency of one area reach a set value. Finally, a typical two-area AC/DC parallel hybrid transmission system is simulated. And the simulation results show that the proposed algorithm has a high accuracy and a rapid computation speed, which proves its applicability and effectiveness as well as prospects of coordinating with emergency frequency control and online application.