A Fuzzy Logic Based Power Electronic System for Wind Energy Conversion Scheme Lata Gidwani 1 Rajesh Kumar 2 1 Department of Electrical Engineering, EC,Ajmer, INDIA 2 Department of Electrical Engineering, MNIT,Jaipur, INDIA E-mail: lata_gidwani@rediffmail.com, rkumar_mnit@rediffmail.com Abstract This paper used fuzzy logic theory to study the behavior of a simple pulse width modulated three phase voltage controlled VSI, which feeds a weak ac network with power produced from an offshore wind farm (WF) of induction generators. Its control system, which is based on fuzzy controllers, manages to offer very satisfactory performance. Using Matlab simulation, the study was performed under both steady- state and transient conditions. The results have proven an excellent performance and verified the validity of the proposed system. The studies have also demonstrated the ability of the advanced inverter to assist the system keeping the ac voltage fluctuations in the point of common coupling at an acceptable level. 1. Introduction Since Zadeh introduced the concept of fuzzy theory [1], fuzzy theory has been widely applied to various areas such as classification, pattern recognition, decision-making, optimization, signal processing, and control. Especially, since its introduction by Mamdani [2], the fuzzy logic control method has been successfully applied to various control problems. The main idea of fuzzy logic control is to use the control ability of human being including the experience and intuition of experts. Therefore, it can be used for various kinds of complex ill-defined processes that can be controlled by a skilled human operator [3-4]. It is interesting to note that the success of fuzzy logic control is largely due to the awareness to its many industrial applications. In this paper, the authors concentrate on fuzzy logic based control of electrical power of Distributed Generation Systems (DGS). DGS can be classified further into stand-alone and grid connected systems (series and parallel processing), according to the output of the voltage source inverters (VSIs) and connection to other ac sources and loads [5]. Typical examples of other ac sources are any available grid (strong, weak, or diesel grids) or other DGS sources. VSIs are inherently efficient, compact, and economical and offer numerous functions that require a minimum number of power conversions [6]. The parallel processing DGS controls power flow and quality by controlling the power conversion between the dc bus of bi-directional VSIs and the available grid [7-8]. The bi- directional VSIs can be further classified into Voltage Controlled VSIs and Current Controlled VSI, depending on their control mechanism [9]. In DGS, VCVSIs use the amplitude and phase of an inverter output voltage relative to the grid voltage to control the power flow [10]. In VCVSIs, the desired current flow is generated by controlling the voltage across the decoupling inductor. The CCVSI uses switching instants to generate the desired current flow in the VSI’s inductor filter, using instantaneous current feedback [11]. This International Conference on Computational Intelligence and Multimedia Applications 2007 0-7695-3050-8/07 $25.00 © 2007 IEEE DOI 10.1109/ICCIMA.2007.83 395 International Conference on Computational Intelligence and Multimedia Applications 2007 0-7695-3050-8/07 $25.00 © 2007 IEEE DOI 10.1109/ICCIMA.2007.83 395