Research On Power Smoothing Output Of The Wind Farm Based On The Hybrid Energy Storage System

As the wind has the characteristics of volatility and intermittent, it will cause the strongimpact when the wind power system was connected to the grid and lead to a series ofreliability problems. The larger capacity the wind power system provides, the bigger influenceto the grid it causes. The energy storage system is the excellent equipment which can’t bereplaced in the field of power smoothing. The paper did the analysis of control strategy andthe capacity optimization according to the hybrid energy storage system. The following arethe main contents:The paper proposes a hybrid energy storage system which consists of battery and supercapacitor based on the wind power system. The system takes the advantage of thecharacteristic of the two energy storage system to compensate the power smoothing of thewind power system. In the paper a fuzzy control strategy is proposed to consider the SOC andactive power reference in order to avoid the hybrid energy storage equipment being overusedor super saturation. The simulation shows that the hybrid energy storage system has theexcellent compensation effect and it can prolong life of the energy storage. This kind ofenergy storage system has the practical value and can be used to improve existing energystorage system.As the capacity configuration of the energy storage system affect the economy of thewind power system directly, the paper proposed a new capacity configuration method whichis based on the chance-constrained programming. The method takes the power output andSOC of the energy storage system into account, with the lowest cost of the equipment as thegoal. Then using the genetic algorithm to obtain the relationship between the best cost and theconfidence which the power fluctuation inferior to. The method achieves the compromisebetween the power smoothing and the economy. The simulation shows that the method canavoid the increasing cost which caused by the volatility of the wind power system. Comparedto the traditional capacity configuration, it’s more flexible and practical.