Benchmark model of the DC sending-end system with high-penetration renewable energy for voltage stability analysis

Introduction With the increasing integration of renewable energy, the power grid is gradually facing multi-mode voltage stability problems, especially at the DC sending end. Thus, there is an urgent need to meet the voltage security and stability requirements of the DC sending-end power grid under different scenarios. Methods Based on the topology and operational data of an actual Chinese DC sending-end power grid, a high-penetration renewable-energy DC sending-end system was established using the Power System Analysis Synthesis Program. The system integrates 500 kV AC and ±800 kV DC networks, as well as renewable energy sources and synchronous generators. Typical multi-mode voltage stability scenarios, including transient overvoltage, low-high voltage interlocking, delayed voltage recovery and voltage collapse, were constructed under specific faults such as DC bipolar lockout and commutation failure. Key influencing factors of multi-mode voltage stability were systematically analyzed, including DC power output, the penetration of renewable energy, renewable energy control parameters, and the configuration of condenser. Results Simulation results indicate that the proposed model can well reflect the voltage stability characteristics under different scenarios and meet the requirements of voltage security and stability analysis for the high-penetration renewable energy DC transmission system. Discussion The established simplified model can serve as a basic platform for voltage stability analysis, providing a reliable foundation for subsequent related research on the voltage stability of DC sending-end power grids with high renewable energy penetration.