利用抽水蓄能黑启动大型火电机组辅机的频率估计

针对抽水蓄能机组远方起动大型火力发电机组辅机的过程,提出一种系统频率估计的解析方法。根据调速器软反馈放大倍数远大于硬反馈放大倍数的特点,对抽水蓄能机组的传递函数进行化简。利用经验公式从感应电动机铭牌参数中获取计算参数。通过对抽水蓄能机组和火电机组辅机组成的小系统模型进行拉氏反变换得到系统频率的解析表达式。算法具有所需参数少、计算速度快的特点。以山东电网实际黑启动预案为例,与PSCAD/EMTDC仿真结果的对比表明,算法计算速度显著提高,系统最低频率偏差小。

Frequency estimation of power plant black-start by pumped storage unit

An analytical estimation of power system frequency response during the startup of power plant large auxiliary motors from remote pumped-storage units is proposed. As the soft feedback magnification of governor is far greater than that of the hard feedback,the transfer function model of pumped-storage unit is simplified. The parameters of induction motor are calculated using empirical formula according to its nameplate parameters. The frequency analytical expression of the power system composed of the pumped-storage unit and the auxiliary motors is deduced by the inverse Laplace transformation. The needed parameters are fewer and the computing speed is faster. With a black-start scheme of Shandong grid as an example,the computing speed of proposed method is much faster than that of PSCAD / EMTDC simulation,and the frequency deviation is small.