考虑新能源极限并网强度约束的常规机组最小开机方式优化方法

Optimal method of minimum start-up mode for conventional units considering new energy limit grid-connection strength constraint

新能源集群并网系统中需保证一定数量的常规电源提供短路容量以支撑系统电压,而开机容量过大导致新能源可消纳空间减少,故合理优化常规机组开机方式对于兼顾新能源消纳与电网强度至关重要。针对该问题,基于短路比指标计算方法,以临界短路比指标约束建立了常规机组开机方式与新能源并网系统强度之间的耦合模型;然后在满足新能源设备极限并网强度要求的前提下,提出以新能源最大化消纳为目标的机组最小开机方式优化模型,并采用遗传算法和CPLEX求解器相结合的混合策略进行求解。最后以我国三北地区某新能源汇集送端系统工程为例,验证了所提方法的有效性及优越性。

A new energy cluster grid connection system has to encompass a certain number of conventional power sources that provide adequate short-circuit capacity to support the system voltage.However,excessive start-up capacity will reduce the new energy consumption space,so rationally optimizing the start-up mode of conventional unit is crucial to maintaining balance between new energy consumption and grid strength.To solve this problem,based on the short-circuit ratio index calculation method,a critical short-circuit ratio index constraint is used to build the coupling model between the start-up mode of a conventional unit and the strength of the new energy grid connection system.Then given that the ultimate grid connection strength requirements of new energy based equipment are satisfied,the optimization model for minimum start-up mode of a unit is devised to maximize the consumption of new energy,and the hybrid strategy of combining a genetic algorithm and CPLEX solver is used for the solution.Lastly,a new energy collection and transmission terminal system project in three northern regions of China is used as an example to demonstrate the effectiveness and superiority of the method.