抽水蓄能电站一管多机相继甩负荷过渡过程研究

Study on transition process of load successive rejection of multiple units per penstock in pumped storage hydropower power station

本文分析了在抽水蓄能电站一管多机的布置形式中,同一水力单元机组同时甩负荷和相继甩负荷过渡过程特性。研究表明:在相继甩负荷中,后甩机组一旦在最不利时间点发生甩负荷,其尾水管进口最小压力将严重下降,以致不能满足调保参数限制值要求。而后甩机组最不利时间点不一定是取在先甩机组过机流量衰减到0的时刻,应就具体问题,在先甩机组流量衰减至0这段时间内进行延时甩负荷时间点敏感性分析,寻找出最不利组合时间点,以确保电站安全设计与运行。

The characteristics of the load simultaneous rejection and successive rejection of all the power - generation units within one hydraulic unit are analyzed herein for the pumped storage hydropower station with the layout of multiple units per penstock. The study shows that once the latter load rejection unit rejects its load at a most unfavorable moment, the minimum pressure at the inlet of the draft tube will be largely dropped and then cannot meet the limiting value of the regulating assur- ance parameter. However, the moment of the flow rate through the former load rejection unit being decreased to zero cannot always be taken as the most unfavorable moment for the latter one, therefore, an analysis on the sensitivity of the delayed load rejection moment within the period of the flow rate decrease from its beginning to zero must be made for the specific problems concerned, so as to find the most unfavorable combination of time periods and then ensure the safety design and operation of the hydropower station