PERFORMANCE ANALYSIS FOR SHUNT ACTIVE FILTER BASED ON P-Q AND SDM THEORY

B.Indhumathi¹ , R.Beula²

¹PG student- Department of EEE - G.K.M College of Engineering and Technology, Chennai, India

²Assistant Professor- Department of EEE - G.K.M College of Engineering and Technology, Chennai, India

The Intensive use of Power Converters and other non-linear loads, result in an increasing deterioration of the power systems voltage and current waveforms. The presence of harmonics in the power lines results in greater power losses in distribution. To suppress the harmonics, filters are used. The Active Power Filter uses a voltage source inverter to produce the harmonic current components that cancel the harmonic components due to non-linear loads. The switching of the power electronics devices in the shunt active power filter is based on reference compensation current, which is determined by different algorithms. In this project, simulation setup has been developed using MATLAB and performance of three-phase shunt active power filter is studied using different control techniques that are used to generate the reference compensation current, namely instantaneous active and reactive (p-q) theory and synchronous detection method for the control of reactive power and harmonics. Reference current generated by each of the above method is compared with the actual current fed by the VSI circuit and gate pulses of the VSI are modified so that the actual current is equal to the reference current. A comparison is given for different values of load. Capacitor voltage is kept constant by another closed loop with PID controller. Simulations results are obtained for the two methods. From the simulation result it is observed that the total harmonic distortion factor has been decreased nearly to10% as compared to system without shunt active power filter and the power factor is also improved.