基于最优控制原理的暂态稳定预防控制模型

Transient Stability Preventive Control Model Based on Optimal Control in Power System

基于时域仿真得到系统受扰轨迹,给出了暂态稳定预防控制的非线性规划模型。该模型把功角在末端时刻不大于预先设定的门槛值作为暂态稳定约束条件。通过引入最优控制原理,把微分-代数方程所描述的电力系统预防控制转化为以各发电机有功输出为控制量的最优控制问题:重新调整控制量控制各发电机的转子相对角度,使其在末端时刻都不大于设定的门槛值,从而实现了非线性系统的状态转移。所提出的暂态稳定预防控制模型与时域仿真具有同等的模型适应性。经IEEE 39节点测试系统的数值分析结果表明该算法的有效性,估计的精度能够满足实际工程的需要。

This paper proposes a method for preventive control of power system transient stability. Stability constraints of control model used are formed by setting generator angle to be less than a threshold value. Based on the principles of optimal control, the preventive control model of differential-algebraic formulation of power systems is converted to an optimal control problem, where the relative rotor angles of generators are controlled to be less than a threshold value through generation rescheduling when certain severe contingency occurs. The advantage of the method is that it can be applied to systems represented by complex system models. Case studies using 10-machine New England test power system are given to show effectiveness of the method. Accuracy of the results suggests that this method is useful in avoiding transient instability. Hence, the technique can be used in an online preventive control scheme for securing operation of the system.