采用双层优化调度的虚拟电厂经济性分析

Economic Analysis of Virtual Power Plants Based on Bi-Level Optimization Dispatch

目前,分布式电源已经广泛应用于电力系统中。因其具有容量小、分布广泛的特点,难以进行有效管理,而虚拟电厂(virtual power plant,VPP)则较好地解决了这一问题。通过建立VPP的联合调度运行中心,使得分布式电源可以等效为1个联合发电实体参与电力市场调度。通过主网ISO(independent system operator)和VPP的双层优化调度,不仅可以有效提高分布式电源的可调控性,还可以提高分布式电源的整体经济效益。通过在双层优化调度的上下层目标函数中引入弃风惩罚函数,有效提升了新能源并网的利用率,增强了系统对新能源发电的吸纳能力。首先分析了双层优化调度对VPP各机组经济性的提升,然后从VPP调度容量占系统总容量的比例出发,对比分析了VPP不同容量比例对VPP整体经济效益和各个机组净收益的影响。算例结果证明了采用双层优化调度和选取合适的VPP容量比例对于VPP经济效益提升的重要性。

At present, distributed generations（DGs） are widely used in electric power systems. Due to low capacity and widespread locations, DGs are hard to manage. However, by setting up virtual power plant（VPP） operation center, this problem can be well solved. Through independent system operator（ISO） and VPP＇s proper bi-level optimization dispatch, all DGs can be equivalent to a virtual power plant, taking part in electricity market and promoting net profit of each individual. By introducing wind curtailment punishment into objective functions of bi-level optimization dispatch model, renewable energy is integrated into power system more effectively. To indicate VPP＇s internal dispatch advantage, an example was used to illustrate it. Based on analysis of different VPP＇s capacity ratios in whole system, its influence on VPP＇s and each individual＇s net profit was calculated and compared. Examples indicated that bi-level optimization and proper VPP＇s capacity ratio could play an important role in improving VPP＇s profit.