基于WAMS及机组对的电网暂态稳定态势在线量化评估方法

An online Quantitative Evaluation Method of Power System Transient Stability Situation Based on WAMS and Generator Pair

为满足电网实时监控对算法速度和精度的要求,提出了一种基于广域测量系统(wide area measurement system,WAMS)及机组对的电网暂态稳定态势在线量化评估方法。该方法采用简化的发电机等效模型,根据相量测量装置(phasor measurement unit,PMU)量测信息在线跟踪辨识其参数。通过识别受扰相对最严重的机组对,进而可计算该机组对等效的相互作用机械和电磁有功功率,以此为基础提出了一种可直接反映轨迹暂态稳定裕度的量化指标。文中还给出了对WAMS采集轨迹信息的曲线拟合方法和能量型指标,以便快速预估未来暂态稳定性。并以单机无穷大系统为例,验证了可利用发电机端口外PMU有效测量信息间接评估电网整体暂态稳定态势的可行性。最后,面向实际工程给出了暂态稳定态势在线量化评估实施方案。理论分析与仿真测试结果表明了所提方法的有效性及工程可操作性。

To meet the demand of power network real-time monitoring on calculation speed and accuracy of the algorithm, an online quantitative evaluation method of power system transient stability situation based on WAMS and generator pair is proposed. Using simplified equivalent model of generator and measured data by PMU, online tracking and identification of generator parameters are implemented. By means of identifying the generator pair that is disturbed relatively most seriously, the equivalent interactional mechanical and electromagnetic power of the generator pair can be calculated, and on this basis a quantitative transient stability index that can directly reflect trajectory transient stability margin is put forward. In addition, a curve fitting method for trajectory information collected by WAMS and energy index to fast predict system transient stability are given to quickly forecast transient stability in future. Taking a one-machine infinitive bus system as the test system, the feasibility of indirectly evaluating overall transient stability situation of power system by utilizing effectively measured data from PMU outside generator bus is validated. Finally, an actual project oriented implementation scheme for online quantitative evaluation of transient stability situation is given. Results of theoretical analysis and simulation tests show that the proposed method is effective and can be applied in engineering practice.