考虑周期划分特性和储能电池生命周期费用的混合供电系统优化

Optimization of hybrid power systems based on period partitioning properties and life cycle cost of battery

在风/柴/储混合供电系统中,风力发电的不确定性和用户负载的波动性对混合供电系统及其储能电池系统的优化设计和运行具有重要影响。针对混合供电系统,采用k-均值周期划分法考虑风力发电和用户负载的波动性,建立了混合供电系统及其储能电池系统的优化模型。在优化模型中将储能电池生命周期费用作为惩罚函数,将循环次数作为约束,以标准化能源费用为目标对混合供电系统进行优化,分析了风力发电不确定性对混合供电系统优化设计的影响。以能量需求为793 k W·h·d^(-1)的风/柴/储混合供电系统为例,研究了混合供电系统优化设计方法。研究表明,考虑风力发电和用户负载的周期划分后,储能电池系统循环次数显著降低,有利于储能电池使用寿命的延长。按风速特性划分周期时,储能电池系统的年循环次数最少,混合供电系统的标准化能源费用最低。当储能电池在其生命周期内的最大循环次数由2000次提升到10000次时,混合供电系统的标准化能源费用降低幅度可达8.3%~16.6%。

In hybrid wind/diesel/battery power systems, uncertainty of wind speed and volatility of user load have great influences on optimal design and operation of the systems and their battery storage systems. An optimization model of a hybrid power system with the battery storage system was proposed, in which the k-means algorithm was used for partitioning periods and analyzing uncertainty of wind speed and volatility of user load. In this model, the life cycle cost of battery was taken as a penalty function, and the cycle number of batteries was taken as a constraint. The objective function was the levelized cost of energy（LCOE） of the power system. The influence of uncertainty in wind speed on the design of the power system was investigated. A hybrid wind/diesel/battery system with a user load of 793 k W·h·d^（-1） was adopted as an example case to demonstrate the proposed optimization procedure. The results show that the cycle number of battery declines sharply by considering the period partitioning based on fluctuations of wind speed and user load, which is helpful to effectively extend the lifespan of battery. When the running period is divided based on the change of wind speed, the cycle number of battery in one year is the least, and the LCOE of the power system is the lowest. If the maximum cycle number of battery could be prolonged from 2000 cycles to 10000 cycles, the LCOE of the power system reduces by 8.3%—16.6%.