%0 Journal Article %T Development of Control Structure for Hybrid Wind Generators with Active Power Capability %A Mehdi Niroomand %A Dong-Jun Won %J Advances in Power Electronics %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/890945 %X A hierarchical control structure is proposed for hybrid energy systems (HES) which consist of wind energy system (WES) and energy storage system (ESS). The proposed multilevel control structure consists of four blocks: reference generation and mode select, power balancing, control algorithms, and switching control blocks. A high performance power management strategy is used for the system. Also, the proposed system is analyzed as an active power filter (APF) with ability to control the voltage, to compensate the harmonics, and to deliver active power. The HES is designed with parallel DC coupled structure. Simulation results are shown for verification of the theoretical analysis. 1. Introduction To have sustainable growth and social progress, it is necessary to fulfil the energy need by utilizing the renewable energy resources like wind, photovoltaic, biomass, hydro, cogeneration, and so forth [1]. Wind energy is one of the most important renewable energy sources on earth. During the last decade, there has been heavy growth in both the size and the power of wind energy converters [1, 2]. In normal operation, wind turbine produces a continuous variable output power. These power variations are mainly caused by the effect of turbulence, wind gradient, and tower-shadow and control system in the power system. Thus, the network needs to manage for such fluctuations. In the event of increasing grid disturbance, an energy storage system (ESS) for wind energy generating system is generally required to compensate the fluctuation generated by wind turbine [3]. In addition, when an ESS is added to a wind energy system, the grid-tie inverter in this system can exchange both active and reactive power with distribution system by varying the amplitude and phase angle of the converter voltage with respect to the line terminal voltage. This hybrid system can improve power quality of distribution system like an active power filter (APF) [4¨C8]. To achieve good ability of power quality improvement, a high performance control system should be designed for hybrid energy systems [8, 9]. Also, for good interaction between different sources, good power balancing should be considered. There are some researches about power balancing strategy and control algorithm for hybrid energy systems [10¨C16] and active power filters [17¨C19] that present some techniques. In this paper, a hierarchical control structure was proposed for hybrid energy systems. It consists of reference generation and mode select, power balancing, control algorithms, and switching control blocks. Also, a high %U http://www.hindawi.com/journals/ape/2014/890945/