预开导叶对蓄能机组低水头空载稳定性的改善

Improvement of the No-load Stability for Pump-turbines in Low Water Head Condition with Misaligned Guide Vanes

鉴于抽水蓄能机组具有水轮机工况和水泵工况,水力设计会使水泵水轮机全特性曲线上出现倒"S"特性,特别是在水轮机工况时,低水头容易出现空载不稳定,造成机组难以并网的状况,根据蓄能机组的特点,采用预开导叶改善低水头下机组空载的稳定性,通过不断试验,验证了预开导叶在电厂实施的可行性,并已将该功能投入使用,有效地决解决了低水头并网困难的问题。

Because the pump-turbine unit in pumped storage power stations can work in both the turbine mode and the pump mode, its complete characteristic curve presents a reserve S-shape. When the unit operates in the turbine mode under low water head, no-load instability is frequently encountered which will make it difficult to connect with the power grid. The misaligned guide vane technique is thus adopted to improve the no-load stability of the pump-turbine unit. Practical application of this technique in Huizhou Pumped Storage Power Station demonstrates its effectiveness.