Hybrid series active power filter for mitigating power quality problems

This paper presents various power quality problems and its mitigation through a hybrid series active power filter. Series filters have less attention in the power quality area due to its high cost of compensation, bulky transformers etc. Even though hybrid series active power filters are used in three phase system it is less utilized in single phase system. So for above mentioned purposes a transformer less single phase hybrid series active power filter is studied. A novel chattering less sliding mode control algorithm is developed are incorporated with voltage and current control loop which provide source current harmonics elimination coming from voltage fed type of non linear load and other voltage distortions like voltage harmonics, voltage sag/swell initiated through grid. Thus cleaning point of common coupling and enhancing power quality and providing reactive power regulation. Main advantage of the filter is that only less dc voltage is needed for compensation and only small compensation gain is used. Voltage disturbances initiated from power system are obstructed by the compensator and PCC becomes free of voltage harmonics and protected from voltage sag/swell. For tracking and reducing chattering auto-tuning of sliding mode control parameters using fuzzy logic are used. The simulation is done in MATLAB/SIMULINK toolbox and for simulation purpose a 6.2 KVA load that are combination of nonlinear load and linear load is designed and used. In order to show the effectiveness of the proposed topology an experimental prototype of 30W load in combination of both non linear and linear is used.