A Novel Graph-based Accurate Reactive Power Estimation Method for Transmission Lines Considering the Impacts of Shunt Reactors

Due to the discrepancy between the ideal Bus-Branch model and the actual connection configuration of shunt reactors and measurement devices in Node-Breaker model, it is hard to accurately calculate the impacts of shunt reactors on the reactive power estimation of transmission lines. In order to improve the power estimation accuracy for the state estimation in energy management system (EMS), this paper proposes a graph-based reactive power estimation method for transmission lines to overcome the complex network topology processing problem related to the connections of shunt reactors. To achieve efficient and accurate solution for state estimation, this paper developed a graph data model for power system modeling in EMS application and leveraged the advantages of graph computing in handling the topology analysis and achieving parallel computing for state estimation. Based on proposed graph data model, a graph computing based approach is developed to allocate the injected reactive power of the shunt reactors to transmission lines and a nodal paralleled state estimation algorithm is proposed to incorporate the impact of shunt reactors. Finally, the effectiveness of the proposed approach is verified on an existing large-scale power transmission system.