International Journal of Advancements in Technology http://ijict.org/ ISSN 0976-4860 Vol. 4 No. 1(March 2013)©IJoAT 36 Study of the LCL Filter for Three Phase inverter in higher stability for the Active damping Method using Genetic Algorithm Base. Rajendra Aparnathi 1 , Ved Vyas Diwedi 2 1 Electrical Department The Maharaja Sayajirao University Of Baroda The Faculty Of Technology And Engineering, Baroda-Gujarat,India Director, Faculty of Engineering, Noble group of Institution, Junagadh, Gujarat Corresponding Author Email: rajendraaparnathi@gmail.com , director.principalngigmail.com Abstract The use of a LCL-filter mitigates the switching ripple injected in the grid by a three-phase active rectifier or Three-phase inverter (VSI). However stability problems could arise in the current control loop. In order to overcome them a damping resistor can be inserted, at the cost of efficiency. On the contrary the use of the active damping seems really attractive but it is often limited by the use of more sensors with respect to the standard control and by the complex tuning procedure. This research Work introduces a new active damping method that does not need the use of more sensors and that can be tuned using genetic algorithms. It consists of adding a filter on the reference voltage for the converter’s modulator. The tuning process of this filter is easily done, for a wide range of sampling frequencies using genetic algorithms. The resultant active damping solution does not need new sensors or complex calculations. Moreover, the particular attention is devoted to the dynamics of the system due to the introduction of the active damping. Keywords: LCL filter, direct power control (DPC), Voltage source inverter (VSI), Voltage Oriented Control (VOC), pulse with modulation (PWM), 1. Introduction The front-end stage of a power converter is not a mass produced product. In fact it should be specifically designed for the application it is used for, such as chemical, electrolysis, aluminum, graphitizing furnace, zinc electrolysis, copper refining, traction substation, AC and DC drive system. If the attention is focused to applications that can take advantage from dc voltage regulation, the diode bridge with on-load tap changers or with saturable core reactors and the thyristor bridge are still the preferred design solutions in respect to Diode Bridge plus chopper systems [1]. For historical reasons the diode bridge plus chopper have been considered as the “new” solution in the rectifier field. In fact the chopper has been successfully experimented in traction system over the past 30 years. In this scenario, active rectifiers, employing voltage source inverter (VSIs) are valid competitors both for traditional solutions such as thyristor and for newer one as chopper, due to the reduced number of power devices and the capability of grid current and power factor control. Particularly VSIs, employing pulse width modulation (PWM) techniques, are the widest used power converters for applications such as industrial motor drives, robotics, air conditioning and ventilation, uninterruptible power supplies and electric vehicles