考虑柔性负荷的多目标安全约束机组组合优化模型及求解

Multi-Objective Optimization of Security Constrained Unit Commitment Model and Solution Considering Flexible Load

以系统的经济成本和CO2排放量最小为优化目标,兼顾发电侧与需求侧柔性负荷的双侧协调配合,建立了考虑柔性负荷的多目标安全约束机组组合优化模型。针对传统法线边界交叉(normal boundary intersection,NBI)法求解上述模型时出现的混合整数二次规划和混合整数二次约束问题,提出了引入分段线性化策略的NBI法,在保证计算精度的同时,大大提高了求解效率。对一个10机24时段算例进行了仿真计算,一方面证明了所提算法的有效性,另一方面表明柔性负荷调度有利于提高系统的经济性,降低系统的碳排放量;同时,需求侧柔性负荷的参与对减小负荷峰谷差、缓解负荷高峰期用电压力具有重要作用,并促进了风电的进一步消纳,有助于清洁能源的利用。

With objective of minimizing economic cost and CO2 emission, taking into account coordination of power generation side and flexible load, a multi-objective optimization of security constrained unit commitment model considering flexible load is established. However, when traditional normal boundary intersection （NBI） method is applied to solve above model, a mixed integer quadratic programming （MIQP） problem and a mixed integer quadratic constrain problem （MIQCP） have to be solved. Therefore, a NBI method with piecewise linearization strategy is proposed to solve the model. Compared with traditional NBI method, the proposed NBI method can ensure calculation accuracy and greatly improve solution efficiency. Simulation results of a 10-unit system demonstrate effectiveness of the proposed NBI method. The results show that flexible load scheduling in the proposed model can improve system economy and reduce system carbon emission. Participation of demand side flexible load plays an important role in reducing load-peak-valley difference and promotes further accommodation of wind power and clean energy utilization.