Evaluation Method for the Maximum Power Receiving Capability of DC Receiving-end System

The external power receiving capability of the overall AC/DC receiving-end system is mainly restricted by the HVDC bipolar blocking failure. This paper presents a method to evaluate the maximum AC external receiving capability of the receiving-end power grid. Firstly, the power flow transfer ratio of the AC transmission line is analyzed after the HVDC bipolar blocking occurs in the receiving-end power grid under the given operation mode. Then, according to the thermal stability limit constraint of the AC transmission line, the initial power flow is calculated when the power flow just satisfies the power constraint after the power flow transfer. The calculated initial power flow is used as the optimal power flow distribution under the maximum power receiving capability of the receiving-end power grid. Next, the power flow transfer capability indexes of AC transmission lines and transformers and the maximum power receiving capability margin are defined. The objective function is established to analyze and evaluate the maximum external receiving capability of the receiving-end power grid under different operation modes. Finally, the effectiveness and adaptability of the proposed method are verified by taking a provincial receiving-end power grid as an example.