含HVDC与P2G的跨区域电-气互联系统优化调度

远距离直流外送和电能转换存储是实现高比例可再生能源消纳的重要手段。考虑跨区层级高压直流输电(high-voltage direct current,HVDC)和区域内电转气(power to gas,P2G)相配合,提出面向大规模风电消纳的跨区域电-气互联系统优化调度策略。首先,针对HVDC功率传输计划独立编制难以匹配风电出力强随机性的问题,建立HVDC阶梯式运行优化模型。同时,考虑风电反调峰特性提出利用P2G进行风电转换,并与天然气系统管存配合实现间接存储。然后,综合考虑系统电压稳定性等安全约束条件,以系统运行经济性最优为目标建立日前优化调度模型,并针对模型非凸、非线性问题,采用电压幅值精确计算的线性化潮流和分段线性化方法进行处理。最后,通过多个场景仿真分析,验证了所提优化策略的有效性和经济性。

Optimal Dispatch of Cross-Regional Integrated Electricity-Gas System with HVDC and P2G

Long-distance DC transmission and power conversion and storage are important means to achieve high proportion consumption of renewable energy. Considering the cooperation between cross-regional high-voltage direct current (HVDC) and intra-regional power to gas (P2G), a cross-regional integrated electricity-gas system optimized dispatch strategy for large-scale wind power consumption is proposed. First of all, in view of the problem that independent preparation of the HVDC power transmission plan is difficult to match the strong randomness of wind power, an stepped operation optimization model for HVDC is established. At the same time, considering the anti-peak regulation characteristics of wind power, it is proposed to use P2G for large-scale wind power conversion and to realize indirect storage cooperate with line storage of gas system. Then, considering the safety constraints such as the system voltage stability, the day-ahead optimal dispatch model is established with the goal of optimal system operation economy, the linear power flow algorithm with high voltage accuracy, and the piecewise linearization method are used to address the non-convex and nonlinear model. Finally, the effectiveness and economy of the proposed strategy are verified by several simulation results.