J. Electromagnetic Analysis & Applications, 2009, 1: 15-23 Published Online March 2009 in SciRes (www.SciRP.org/journal/jemaa) Copyright © 2009 SciRes JEMAA 1 Impact of Reactive Power in Power Evacuation from Wind Turbines Asish Ranjan 1 , S. Prabhakar Karthikeyan 1 , Ankur Ahuja, 1 K. Palanisamy 1 , I. Jacob Raglend 2 , D. P. Kothari 3 1 School of Electrical Sciences, Vellore Institute of Technology, Vellore, India-632014, 2 Christian College of Engineering and Tech- nology, Ottanchatiram, Dindugal District. India-632014, 3 Vellore Institute of Technology University, Vellore, India-632014. Email: asran@vestas.com; spk25in@yahoo.co.in; ahuja.ankur.1986@gmail.com; kpalanisamy79@yahoo.co.in; jacobraglend@rediffmail. com; dpk0710@yahoo.com; vc@vit.ac.in Received January 31 st , 2009; revised February 17 th , 2009; accepted February 28 th , 2009. ABSTRACT Application of Distributed Generation (DG) to supply the demands of a diverse customer base plays a vital role in the renewable energy environment. Various DG technologies are being integrated into power systems to provide alterna- tives to energy sources and to improve reliability of the system. Power Evacuation from these remotely located DG’s remains a major concern for the power utilities these days. The main cause of concern regarding evacuation is con- sumption of reactive power for excitation by Induction Generators (IG) used in wind power production which affects the power system in variety of ways. This paper deals with the issues related to reactive power consumption by Induc- tion generators during power evacuation. Induction generator based wind turbine model using MATLAB/SIMULINK is simulated and its impact on the grid is observed. The simulated results are analyzed and validated with the real time results for the system considered. A wind farm is also modeled and simulations are carried out to study the various im- pacts it has on the grid & nearby wind turbines during Islanding and system event especially on 3-Phase to ground fault. Keywords: Distributed Generation (DG), Grid, Wind Turbines, Induction Generator, Islanding, Power Evacuation, Point of Common Connection 3 Phase to Ground Fault 1. Introduction Wind is one of the most important resources found in nature’s bounty totally free of cost and without any hazardous effects. Perhaps that is why, in this hour of energy crisis,the entire human race has diverted its attention to wind energy as a suitable alternative to the conventional sources of energy we have been using for more than a century. Having an insight into the statistics concerning installed wind power capacity,we see that the total capacity as of today is 93,849MW (2008). India stands fourth in wind power commissioning with an installed capacity of 7844.5MW (2008). But Germany with a capacity of 22,247MW (2008) shows that the distance to be covered is still huge. Of course, it instills a hope that the future will be bright with no reliance on conventional sources of energy and wind energy forming a large chunk of the installed capacity. There are two types of utility-scale wind turbines, fixed- and variable-speed. Fixed-speed wind turbines operate at a near constant rotor speed at all times and are directly connected to the power grid [1]. Fixed speed wind turbine which is used here for analysis operates within a very small range (around 5% of the nominal value) and in general they use a fixed shunt capacitor to provide reactive power compensation [2]. 1.1 Islanding A phenomenon which generally occurs in a network with Wind Generation in which a portion of the distribution network becomes Electrically Isolated from utility grid due to transmission system events & after disconnection, wind generator maintains supply to local loads. Islanding can be categorized as Intentional Island and Unintentional Island. Islanding is a condition in which local Distribution Generation systems continue to supply stable real power and reactive power to the local loads at a sustained voltage and frequency while the main Energy system is de-ener- gized. An islanding condition creates a safety hazard and may cause damage to power generation and power supply facilities as a result of unsynchronized re-closure [3]. In general, after loss of the main source, the DG has to take charge of the remaining network and the connected loads; therefore, the loading condition of the DG is suddenly changed after islanding. Since the distribution networks generally include single-phase loads, it will be highly pos- sible that the islanding changes the load balance of DG [4]. 1.2 Intentional Island Planned islanding is often called Intentional Islanding. This condition arises when a portion of the network is