考虑一次调频能力的火电机组负荷优化分配

Load Optimal Distribution of Thermal Units Considering Primary Frequency Control Ability

机组调峰深度与调峰能力在一定程度上不可兼得,为使电力系统运行经济的同时具备足够的调峰裕度,提出了考虑一次调频能力的机组负荷优化分配模型,引入新型正弦余弦算法(sine cosine algorithm,SCA)求解。以某电厂4台机组为例验证模型的有效性,分别采用SCA和遗传算法(genetic algorithm, GA)寻优计算并与自动发电控制(automatic generation control,AGC)指令对比,结果表明SCA的最优解比GA精度更高,而且新模型既能保证足够的一次调频备用容量又有更高经济性。通过仿真得出不同负荷率最优经济成本与一次调频备用容量的关系曲线,总结了此规律对负荷优化分配的指导意义。最后仿真研究低负荷率时的负荷分配,结果表明模型会优先选取经济性较好的机组进行深度调峰以保证整体最佳经济性。

It exists a contradictory relationship between ability of peak shaving and load rate. In order to improve the economy of electric power system operation and ability of peak shaving simultaneously, optimal load distribution model considering the primary frequency control ability(PFCA) was proposed. Furthermore, sine cosine algorithm(SCA) was introduced to solve it. Taking four units as simulation example to verify the model. The results show the SCA can achieve better performance than genetic algorithm(GA) in calculating optimal value. Compared with the automatic generation control(AGC), the new method was more economical and meet the requirements of the PFCA. In addition, the relationship between optimal economic cost and primary frequency control capacity under different load rate was summarized by simulation. It has great guiding significance for load optimal distribution. Finally, load optimal distribution in low load rate was studied. The results show the units with better economy were selected preferentially to participate in deep peakregulating.