Shunt active power filter with a three-phase neutral-point-clamped inverter for power quality improvement based on fractional order proportional integral control

Abstract

The quality of the electrical wave is far from being perfect, due to the use of nonlinear loads that generate current harmonics and consume reactive power. Knowing the origins and the effects of pollution harmonics on the electrical networks, this study is to implement a system of active filters with three levels inverter hysteresis-based control which injects into the network a current equal to those absorbed by the polluting load and out of phase, thus leading the supply current to be sinusoidal. The regulation and the stability of the power supply of the filter during a variation of the load is ensured by a classical proportional integral (PI) controller and then by a fractional order PI controller (FOPI). Several cases of simulation accompanied by a temporal analysis and a spectral analysis were carried out starting from the model of the supply network, nonlinear load and parallel active filter. The simulation results of the proposed methods show that the parallel active filter can effectively suppress the current harmonic to force the supply current to be sinusoidal and compensate the reactive power generated by the nonlinear load.