Stability behavior of load adjustment and primary frequency control of pumped storage power plant with upstream and downstream surge tanks

Abstract

This paper studies the stability behavior of load adjustment and primary frequency control of pumped storage power plant (PSPP) with upstream and downstream surge tanks (UDST). Firstly, the model of PSPP with UDST under load adjustment and primary frequency control is established. The stable domains of PSPP with UDST under load adjustment and primary frequency control are determined. The influence of flow inertia and head losses of connecting pipes of UDST on stable domains is analyzed. The critical stable sectional areas (CSSAs) of UDST under load adjustment and primary frequency control are determined and analyzed. The results show that the stability of PSPP with UDST under load adjustment is usually better than that of PSPP with UDST under primary frequency control. Under load adjustment and primary frequency control, the flow inertia of connecting pipes of UDST is unfavorable for the stability of PSPP, while the head losses of connecting pipes of UDST have no impact on stability of PSPP. Under load adjustment, the CSSAs of UDST present a complex change rule in reference to different governor parameters. Under primary frequency control, the CSSAs of UDST present a monotonic change rule in reference to different governor parameters. With the rise of CSSAs of UDST, the stable domains under load adjustment and primary frequency control become larger.