Capacity Optimal Research Of Hybrid Energy Systems For Wind/PV System Based On Improved PSO

Because the output of the wind,light has the characteristics of randomness and intermittent,combined with the load power also has certain volatility,exacerbating the unbalanced power fluctuations,this will be not conducive to the stable and reliable operation for Wind/PV system,using the energy storage system is an effective method to solve this problem.But the cost of energy storage device is higher,so the study of capacity optimal of hybrid energy storage systems for Wind/PV power generation systems has important practical significance and application value.First of all,this paper expounds the principle of wind power and photovoltaic power generation and its output model,and from the remaining power recursive relations,energy storage device charged state of(SOC)and power constraints,taking this a few point of view to mathematical modeling of energy storage device;Secondly,we select the data of the typical day to represent typical years throughout the year as the basic database.In view of the different operation mode of the Wind/PV system,solving the hybrid energy storage compensation power.Adopting digital filtering algorithm for the distribution of the energy storage power,then calculating the power rating and capacity;Finally,for the stand-alone Wind/PV power generation systems,taking the balance of system power,the charging and discharging power of hybrid energy storage systems,SOC characteristics and Loss of power supply probability(LPSP),Waste of power supply probability(SPSP)as the constraint conditions,taking the minimal total cost of hybrid energy storage systems in view of the energy storage life within the engineering use fixed number of year as the objective function;For the interconnection Wind/PV power generation systems,taking the balance of system power,the charging and discharging power of hybrid energy storage systems,SOC characteristics and the volatility of the net power as the constraint conditions,taking the minimal total cost of hybrid energy storage systems in view of the energy storage life within the engineering use fixed number of year and the total cost of buying and selling electricity as the objective function.The rain flow count method was applied to evaluate energy storage life,and use the linear weighting particle swarm optimization(PSO)algorithm to solve the optimization problem,then getting the best fitness function value and the corresponding optimal capacity.Through comparing the compensation effect of before joining energy storage,membership of the single battery energy storage and hybrid energy storage of battery&super capacitor,the results show that the mixed with super capacitor energy storage system,has more obvious advantages in reducing the total costs and improving the system reliability index:Loss of power supply probability(LPSP),Waste of power supply probability(SPSP).