Static compensator for maintaining voltage stability of wind farm integration to a distribution network N. Aouzellag Lahaçani a, * , D. Aouzellag a , B. Mendil b a Department of Electrical Engineering, Faculty of Technology, A. Mira University, 06000 Bejaia, Algeria b Department of Electronic, Faculty of Technology, A. Mira University, 06000 Bejaia, Algeria article info Article history: Received 25 December 2009 Accepted 10 March 2010 Available online 24 April 2010 Keywords: Wind generator Power flow NewtoneRaphson algorithm Static compensator (STATCOM) Voltage stability abstract Electricity generation from wind has grown sharply and its growth potential is still significant. However, the decentralized nature of the wind opposes the historically centralized structure of national networks. Unlike conventional sources, wind does not provide reactive power, which is necessary to maintain acceptable voltage conditions on the network. The use of Flexible AC Transmission Systems (FACTS) in distribution network to compensate for vagaries such as production related to wind energies and to control the voltage is an optimal solution. This paper is aimed at presenting a point of view on the wind power generation control issues. The main idea is to propose the use of a FACTS such as the STATCOM, which is a compensation device that is capable of generating and/or absorbing reactive power and in which the output can be varied to control the specific parameters of an electric power system and improve the quality of the energy provided, i.e., to regulate the desired power flows in a power network and to provide the best voltage profile in the system as well as to minimize the system transmission losses when inserting the wind generator in the electrical network. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction The main problem regarding wind power systems is the major discrepancy between the irregular character of the primary source (wind speed is a random, strongly non-stationary process, with turbulence and extreme variations) and the exigent demands regarding the electrical energy quality: reactive power, harmonics, flicker, etc. Thus, wind energy conversion within the parameters imposed by the energy market and by technical standards is not possible without the essential contribution of automatic control. The increased share of wind in electricity generation makes more and more complex integration in the system of electricity transmission [1,2]. The fluctuating and unpredictable nature of wind generation complicates network management: the presence of replacement capacity [3e5] is needed to offset periods of low production of wind turbines, because, the wind generator did not participate in the supply/demand balance or maintenance frequency, and does not provide reactive power, which is necessary to maintain acceptable voltage conditions on the network. In periods of high wind, stopping of conventional power plants in favor of wind power can result in a shortage of reactive power. This deficit must be offset by dedicated devices. For these reasons, the rate of wind in the electricity production beyond who are the fluctuations of the production become very complex to manage is estimated between 20% and 30% of the total power. It may be more advantageous for the network operator to invest in means of production of reactive energy that reward the produc- tion of energy by independent producers. Especially since the compensators are free to be displaced in the network to respond to changes in operating conditions. Such systems are to be considered in decentralized networks to overcome the vagaries of production. Technological innovations based on power electronics, which are the FACTS devices such as STATCOM allow the parks to partic- ipate in system services through, inter alia, the remote control and output voltage adjustment [6,7]. The introduction of remote control and operating systems, can further contribute to increasing the reliability of power systems and to improving the quality of the so- called “electricity” product. 2. Purpose of the work Wind turbines can have considerable fluctuations in the output power, due to the stochastic nature of the wind. As a result of that, * Corresponding author. Tel.: þ213 72 32 30 01. E-mail addresses: nlahacani@yahoo.fr (N.A. Lahaçani), aouzellag@hotmail.com (D. Aouzellag), bmendil@yahoo.fr (B. Mendil). Contents lists available at ScienceDirect Renewable Energy journal homepage: www.elsevier.com/locate/renene 0960-1481/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.renene.2010.03.010 Renewable Energy 35 (2010) 2476e2482