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 kW·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%.