Study on the Reversible Pump-Turbine Closing Law and Field Test

In the operation of pumped storage plant, the sudden change of load in the large range often happen, the design of reversible pump-turbine emergency closing law should satisfy limit of rotation speed-rise and pressure-rise. The broken-line closing law of reversible pump-turbine usually used in pumped storage plants is discussed and based on full hydraulic characteristic of reversible pump-turbine, the broken-line closing law of three stages with delayed segment is designed, virtues and defects of the pump-turbine emergency closing law are also analyzed. Numerical calculation and field test indicate that water hammer in pumped storage plant water conveyance system caused by wicket gate closing together with rotation speed-rise, is effectively reduced by the closing laws presented above, especially to the latter, its turning point position can change following the different operating case, the detection of poor robustness is overcome. A new idea for the design of the reversible pump-turbine emergency closing law is proposed with good prospects.