Paper Title
Four Switch Power Conditioner for Voltage Sag Mitigation

One of the most important issues related to power quality solutions is the voltage sag generated by the increasing number of nonlinear loads connected to the power grid. The active power filter, consisting basically of a voltage source inverter with a large capacitor on its DC-Link, is considered a well established solution to reduce the voltage sag to the recommended standard limits. The major drawback of active power filters is the high power rating components and their associated costs. Therefore we go for passive filters which can handle large currents and high voltages. Also, these require less number of components and lowers noise. For a better control of voltage sag, back to back 12 switch inverter was developed. Since high power rating devices are required in case of 12 switch converter, nine switch converter was proposed to reduce the cost by having lesser number of switches. This project involves the control of voltage sag in single phase using four switch power conditioner. PWM scheme is proposed for producing gating signals for four switch inverter. The passive filter and inverter output signal compensate the voltage sag and performance of the proposed four switch power conditioner is validated and then simulated using SIMULINK. Index Terms - Voltage sag, Active power filter, Passive filter, PWM, Four switch power conditioner.