Dynamic Adjustment Strategy for Leading Phase Ability Improvement of Doubly-Fed Induction Machines in Pumped Storage Unit

Pumped storage power station's leading phase operation can balance the surplus power, stabilize the voltage, achieving smooth regulation, so as to smooth the load fluctuations. The phase operation of the unit requires no additional investment, the adjustment process is smooth, and the operation is simple, which is the first choice to solve the existing reactive power surplus problem. The paper explores the limitations of the leading phase range of variable speed hydro-generating unit and proposes a novel strategy for controlling it. It establishes a mathematical model of the unit., then the coordinate transformation is carried out and the relevant control theory is put forward. The factors limiting the reactive power regulation limit of the unit are fully considered. Finally, in the limit boundary, by controlling the slip rate, the variable speed unit can reach the phase range that the constant speed unit cannot reach. This strategy not only improves the phase entry range of the pumping and storage unit, but also increases the phase entry speed.