Multi-time Scale Coordinative Strategy of Reactive Power and Voltage Control for Frequent Power Flow Fluctuation in New Power System

Abstract

With the rapid growth of new energy and flexible load, the random fluctuation of power system operation is enhanced, and the traditional voltage control scheme is limited. In view of the shortcomings of traditional reactive voltage control in matching the dual characteristics of the source and load in new power system, a multi-time scale coordinative strategy of reactive power and voltage control for frequent power flow fluctuation in new power system is proposed, and the reactive power and voltage control is carried out according to the normal and the unexpected large fluctuation of the power flow. The reactive power and voltage coordinated control mode of hour-minute level is used in the normal fluctuation of power flow. The timely adjustment of voltage deviation and the rapid suppression of voltage fluctuation are realized by MPC rolling optimization and dynamic-static reactive power resource substitution, and sufficient dynamic reactive power reserve is reserved for the system. The reactive power and voltage coordinated control mode of second level is used in the case of non-expected large fluctuation of power flow, and the fast decision-making ability of deep reinforcement learning realizes the rapid recovery of over-limit voltage. An example of a regional power grid in eastern China verifies the effectiveness of the proposed method.