Contingencies occurring in multi-terminal high voltage direct current (MT-HVDC) grids can result in DC voltage/flow violations and also affect the frequency stability of the connected multiple asynchronous grids. To recognize and control such notable operating risks, a novel flexible risk-limiting optimal power flow (FROPF) for the MT-HVDC grid with vast wind generation is proposed in this paper. Within the two-stage FROPF structure, the pre-contingency operation of grid-side voltage-source converters (GVSCs) is optimized to minimize MT-HVDC grid power losses. Immediately following an outage occurring in the MT-HVDC grid, various fast-acting corrective actions of GVSCs are utilized to hedge against the overall risk exposure, including the wind power curtailment risk of the MT-HVDC grid and the rate-of-change-of-frequency (RoCoF) violation risk imposed on associated asynchronous grids. Reformulation techniques are introduced to ease the computational complexity of the optimization model. Case studies of two MT-HVDC grids demonstrate the effectiveness of the proposed FROPF.

中文翻译：

---

借助风力发电实现多终端HVDC电网的灵活风险限制运营

多端子高压直流（MT-HVDC）电网中发生的突发事件可能会导致违反直流电压/流量，并且还会影响所连接的多个异步电网的频率稳定性。为了识别和控制这种显着的运行风险，本文提出了一种适用于具有大风量的MT-HVDC电网的新型灵活的风险限制最优潮流（FROPF）。在两级FROPF结构中，优化了电网侧电压源转换器（GVSC）的事前操作，以最大程度地减少MT-HVDC电网的功率损耗。MT-HVDC电网发生故障后，GVSC会立即采取各种快速纠正措施来对冲总体风险，包括限制MT-HVDC电网的风力发电风险以及对关联的异步电网施加的频率变化率（RoCoF）违规风险。引入了重新构造技术以减轻优化模型的计算复杂性。对两个MT-HVDC电网的案例研究证明了所提出的FROPF的有效性。