电力系统实用动态安全域的降维与还原

提出了一种在注入功率空间中求取电力系统实用动态安全域(PDSR)的超平面形式的临界稳定边界的新方法。通过对电力系统进行数值仿真搜索到大量临界点，并通过最小二乘法拟合得到临界超平面的方法精确但费时，难以实际应用。为了在重要的预想事故下快速、准确地求取电力系统的临界超平面，文中提出首先将高维的电力系统通过基于相关的动态等值化简为低维的等值系统，再对其进行数值仿真，拟合出等值系统的临界超平面，然后根据动态等值逆过程推导出超平面还原的解析表达式，最后修正还原得到超平面的系数，使所得到的超平面通过一个由对原系统的详细模型进行仿真得到的临界点，可以在一定程度上改善临界超平面的精度。算例结果证明这种方法兼顾了临界超平面求取的速度与精度，使PDSR在实时安全性分析中的应用更易实现。

REDUCTION AND RECONSTRUCTION OF POWER SYSTEM PRACTICAL DYNAMIC SECURITY REGION

An effective method is proposed for obtaining the critical boundaries of hyper plan (HP) form of practical dynamic security regions (PDSR) of power systems in power injection space. The critical HP of PDSR is basically constructed by the least-square approximation approach (LSA), which uses lots of critical points searched by numerical simulation on the power system. Although accurate enough, this method is so time consuming that it cannot meet real time application of power systems. In order to determine the critical HPs of a power system for a specific contingency rapidly and accurately, the original system with high dimension is firstly reduced to an equivalent system with lower dimension by dynamic equivalent reduction based on coherency. The critical HP of the equivalent system is obtained through numerical simulations and fitting by LSR and then the analytic expressions for hyper plane reconstruction are derived on the base of reverse process of dynamic equivalents. At last the reconstructed critical HP coefficients errors caused by the equivalents are corrected to some extent by translation of the HP to a real critical point, which is obtained through numerical simulation on the power system with the detailed model. Results of the case studies show that this method can save much time while keeping the accuracy acceptable in engineering practice and thus PDSR becomes easier to be applied in real time security analysis.