基于PEBS法的暂态能量裕度灵敏度快速计算

提出了一种基于PEBS法暂态稳定分析的能量裕度灵敏度计算方法。该方法以系统故障前稳定平衡点作为暂态势能参考点,沿持续故障轨迹采用数值方法计算暂态势能。在系统持续故障仿真和灵敏度动态方程计算过程中,引入高阶Taylor级数展开技术,可以在保持计算精度的前提下提高计算步长,显著提高计算速度。将到达临界势能点的判据展开以时间为自变量的多项式形式,通过解方程求得到达临界势能点的时间,从而快速确定临界势能点的位置。提出的能量裕度灵敏度分析方法包括两方面:计算故障前机组机械注入功率变化对能量裕度的灵敏度,用于指导预防控制;计算故障切除后的控制措施对稳定裕度的影响,用于指导紧急控制。New England 10机系统算例验证了该方法的有效性。

A fast method for sensitivity analysis of transient energy margin based on PEBS method

A novel method for transient energy margin sensitivity analysis based on PEBS method is proposed.In this method,the system pre-fault stable equilibrium point is selected as reference point of potential energy,and potential energy is computed along with the system fault-on trajectory by numerical method.In the process of system dynamic trajectory simulation and integration of sensitivity dynamic equations,Taylor series expansion technique is used to calculate the high order derivatives of rotor angles,speed and sensitivity variables with respect to time.Therefore,bigger simulation time step can be employed,which can improve computation speed while keeping normal calculating precision.By solving the polynomial equation with respect to the variable of time,which describes the criterion of the trajectory reaching the critical potential energy point,the critical potential energy can be attained rapidly.The proposed method for energy margin sensitivity analysis includes: energy margin sensitivity with respect to mechanical input power of generators before disturbance occurrence which is used for preventive control,and with respect to control actions after disturbance clearing which is used for emergency control.Simulation results on New England 10-generator system show this method is of good accuracy and the prospect of on-line application is bright.