水泵水轮机“S”特性对机组水头低时发电影响及对策分析

Analysis on the Influence of S character of Pump Turbine on Unit Generating Electricity Under Low Water Head Together with Its Countermeasures

介绍了水泵水轮机“S”特性并从理论上分析了其形成的原因。由于活动导叶与固定导叶的共同作用，抽水蓄能机组水头低时发电，导叶异步开启时，进入转轮前部分水流的流速得到了提高，并高于导叶同步开启时进入转轮前水流的流速。从而有效地改善了对应空载工况点处的“S”特性，解决了水泵水轮机“S”特性此时对机组运行的不利影响。并结合实例进行了分析。

The S character of pump turbine was introduced and its formation cause was theoretically analyzed. Due to the joint efforts of movable and static guide vanes, the flow velocity of partial current was increased before entering runner when the pump storage groups generated electricity under low water head and when the guide vanes were opened asynchronously. The increased velocity has exceeded that of when the guide vanes were opened synchronously. This has effectively improved the S character at the no-load operating point, reduced its negative impact on the unit operation. Case study has been given in the end.