Modelling and analysis of a hybrid active power filter for power quality improvement using hysteresis current control technique

Power system comprises of three natural / physical characteristics namely voltage, current and frequency. Deviation in these physical characteristics are termed as power quality issues in power system. Presence of nonlinear current or nonlinear/unbalanced voltages and frequencies are termed as power quality issue. These (current, voltage and frequencies) deviations result in failure/damage of equipment in power system. Power electronic converters associated with their nonlinear switching characteristics and high frequency operation are the major cause for power quality issues. In order to reduce harmonics and improve power quality, Hybrid Active Power Filter (HAPF) particularly shunt HAPF are employed. Both voltage and current harmonics can be eliminated using instantaneous real and reactive power compensation (p-q) control technique. The PI based controller is used for power compensation calculations. A mathematical modeling on both p-q theory control is explained. Simulation is carried out using MATLAB/SIMULINK and the results are presented for different compensation filters at different load conditions.