Control Strategy of a Single Phase Active Power Filter with Adjustable DC Link Capacitor Voltage for THD Reduction in Non-linear Loads

The presence of nonlinear and unbalanced loads in the single phase networks increases the harmonics and losses in power grid. The active power filters solve these problems, and in addition to reducing any arbitrary harmonic component, it will eliminate the possibility of resonance with the network. In this paper, an active power filter (APF) based on voltage source converter (VSC) is used to reduce the THD contents of single phase grid current which are applied to a non-linear load. A new hybrid hysteresis current control scheme with a DC link capacitor voltage regulator based on conventional PI controller is proposed to generate the gating signals of APF. The performance of the proposed controller in terms of reducing the THD contents of grid current and power quality improvement is evaluated using MATLAB/Simulink and also an experimental setup is implemented to confirm the simulation results.