Modellation and simulation of shunt active power filters type for variable nonlinear load

Abstract

The paper is dealing with modelling and simulation of running principle of shunt type active power filter. It is possible to highlight the running of the active filter as a result of correlation of power supply voltage, the power outage on filter coil and converter input voltage. The mathematical equations for filter running were implemented into the PSIM software, both with instantaneous variables without DC voltage control and Vdc voltage control in the (dq) coordinate system. The numerical simulations performed without DC voltage control have shown a Vdc voltage overgrown. Vdc voltage control is taking off this inconvenience and allows harmonics balance putting in a filter current in phase opposition with the harmonic current of nonlinear load. By numerical simulation of varable voltage power supply of the nonlinear customer it was highlighted existence of an optimal area of THDi thanks to correlation between grid voltage, coil and converter input voltage. Choosing and dimensioning of three phase coil of power circuit of SAPF has a decisive influence on the voltage range of adjustment of nonlinear customer and implicit on THDi grid current.