Double-Level Power Grid Planning Considering Operational Efficiency and Security

As one key content of future grid development, the methodological rationality of power grid planning has crucial impact on the operational security and stability for the power grid. With rapid development of wind power and photovoltaics, the wind-solar-coal bundled transmission pattern is becoming an inevitable trend in order to balance the mismatch between renewable energy generation and load demand in China, which has caused great challenges to power gird planning. In order to address the uncertainty of wind power generation, a two-level planning model considering N-1 security constraint is established in this paper which divides the grid planning problems into four typical scenarios considering the seasonal characteristics of wind power outputs. The high-level model, comprehensively considering the operational efficiency, aims to minimize the costs of wind-solar-coal bundled power transmission under various operating conditions while the low-level model aims to minimize the load shedding based on N-1 security analysis. Both the high-level and low-level models take N-1 constraint as the primary constraint and the best planning scheme can be obtained through iterations. According to the given planning scheme and the actual operation scenarios, the final scheme can be optimized and selected.