基于相平面特性的切机切负荷紧急控制方法

Combined Emergency Control Strategy of Generator Tripping and Load Shedding Based on the Characteristics of State Plane

提出一种基于相平面轨迹几何特征的切机切负荷联合控制方案。当系统发生暂态扰动时,实施的控制方案能够在保证系统恢复暂态稳定的同时,防止系统的频率电压过低。通过对控制后相轨迹斜率变化特性的分析,得到控制量与相轨迹斜率变化特性的关系;基于发电机的转子运动方程,推导出了相轨迹斜率与控制量关系的数学表达式,从而得到控制量的计算方法。当系统发生暂态失稳时,提出切机切负荷联合控制的启动条件,并给出切机切负荷的分配算法以及实时控制地点的选择方法。在IEEE 39节点系统和三华联网系统的仿真,验证了该联合控制方法的有效性。

A combined emergency control strategy of generator tripping and load shedding was proposed. When power system subjected to disturbances loses synchronization, the strategy can prevent system instability and also improve the frequency and voltage. By analyzing the characteristic of the phase-plane trajectory representation of power angle and rotor speed, the relationship between the unbalanced power and the slope of the trajectory is obtained. Based on the kinematic equation of the rotor, the expression of the relationship between the unbalanced power and the slope is deduced and the control algorithm is derived. And then, the start-up condition of the combined control strategy is presented and the allocation algorithm of generator tripping and load shedding is given. The simulation results in IEEE 39-bus system and the Sanhua system validate the effectiveness of the combined control strategy.