Risk assessment method for integrated transmission–distribution system considering the reactive power regulation capability of DGS

Abstract

High distributed generation (DG) penetration makes the traditional method of equalizing the distribution power system (DPS) to the PQ load bus in the risk assessment of the transmission power system (TPS) no longer applicable. This paper proposes a risk assessment method for an integrated transmission–distribution system that considers the reactive power regulation capability of the DGs. Based on the DG’s characteristics and network constraints, the regulation capacity is mapped to the boundary buses of the distribution networks. Coordinating the relationship between reactive power and active power, the utilization of the regulation capacity is maximized to reduce the load shedding in the fault analysis of the TPS. Simulation results in the integrated transmission–distribution system illustrate that the effective use of the regulation capacity of the DPS can reduce the risk of the TPS. The method can be applied to the reactive power sources planning and dispatching of power system.