一种机组恢复决策的多时段协调优化方法

为加快大停电后电网的恢复速度,在制定机组恢复方案时,应合理安排机组的启动顺序使尽可能多的火电机组实现热态启动。通过分析恢复过程中机组的串并行恢复机制,并考虑机组热启动时限对恢复顺序的影响,提出一种机组恢复决策的多时段协调优化方法。该方法采用分时段建模、多时段协调优化的全局优化策略,以热启动机组的总容量和恢复过程中机组的总发电量分别作为上、下层目标函数,建立了分时段的双层优化模型;采用基于状态优选的多种群遗传算法进行求解,实现了机组恢复决策的全局优化。通过合理控制各时段保留的方案数,既可保证方案的多样性,有效防止求解陷入局部最优,又可确保各时段的状态数有可控的上限,使计算量控制在可接受的范围内。新英格兰10机39节点系统和河北南网实际系统的算例结果验证了所提多时段协调优化方法的有效性。

An Optimization Approach Based on Multiple Time-Step Coordination for Decision Making of Unit Restoration

To accelerate the restoration speed of a power system after a blackout, it is necessary to restore as many thermal units as possible within their hot-start intervals by determining a reasonable unit restoration sequence. By analyzing the serial and parallel restoration patterns of units and considering the effects of the hot-start interval on the restoration sequence, a multiple time-step coordinative optimization approach for decision making of the unit restoration sequences is proposed in the paper. Adopting the global optimization strategy based on multiple time-step modeling and coordinative optimization, a bi-level optimization model based on time-step is established, in which the total capacity of the hot-started units and the total units’ MWh output in the overall process are treated as the upper-level and the lower-level objective functions respectively. The multiple population genetic algorithm ( MPGA ) based on optimal choice of states is employed to solve the model. So the global optimization for unit-restoration decision making is achieved. By reasonably controlling the number of the reserved solutions for each time step, the diversity of solutions is remained to avoid the local traps. At the same time, the limit for the number of states in every stage is added, and the computation complexity is well controlled in an acceptable degree. The effectiveness of the proposed method is validated by the optimization results from the New England 10-unit 39-bus power system and the southern power system of Hebei.