基于综合广域信息的负荷参数辨识方法

Load parameter identification based on wide-area measurement

提出一种基于综合广域信息的负荷参数辨识方法,以发电机相对功角作为广域信息,综合分析多种运行及故障条件下发电机功角对负荷参数的轨迹灵敏度。根据灵敏度分析结果,可以确定参与负荷参数辨识的发电机功角以及各负荷参数的易辨识性,也可以选择有利于参数辨识的扰动地点。由负荷参数估计值得到的发电机功角响应曲线,与发电机功角曲线实际值的最小二乘拟合,使得目标函数极小化,即完成了负荷参数的广域辨识。对10机39节点系统的仿真分析结果表明:负荷参数辨识的广域信号应选择30号发电机功角,节点19为扰动地点,负荷参数中电动机负荷比例系数以及定转子阻抗等灵敏度较高,更易于辨识。在多种运行及故障条件下,广域辨识的负荷参数均能够比较准确地反映系统实际的动态特性。

A load parameter identification method based on synthetic wide-area signals is presented, which takes generator relative angle as wide-area signals to synthetically analyze its traiectory sensitivity to load parameters. The sensitivity analysis results are used to select the generator angle and favorable fault location for load parameter identification, and to determine the identifiability of each load parameter. The wide -area load parameter identification is realized by minimizing the objective function of the least-squares fitting of generator angle response curve, obtained from estimated load parameters, to real generator angle curve. The simulative analysis of a 10-machine 39-bus system shows that, the generator angle of Unit 30 should be selected as wide-area signal and the favorable fault location is Bus 19; the load ratio of induction motor and the impedances of stator and rotor are parameters with high sensitivity and more easily identified. The parameters identified by wide-area identification reflect the real system dynamic performance more precisely for various operation and fault conditions.