Sizing of a Filter (<i>L-C</i>) for a 180° Control Inverter Connected to a Medium Voltage Network

Abstract

This paper studies the design and sizing of a filter (L-C) for an inverter with 180˚ control in Medium voltage (MV), based on formulas of the capacitance of the capacitor C and the inductance L of the filter (L-C) of an SPWM inverter. These formulas were obtained by minimizing two parameters: the reactive power of the capacitor (capped at 5% of the apparent power of the load) and the ripple of the current flowing through inductance L (capped at 10% of the current supplying the load). The application of these formulas for the calculation of the filter (L-C) of the 180˚ control inverter in MV is not conclusive. Studies have been carried out to make them applicable. The results show that limiting the current ripple in the inductor to 10% of the load current is a valid assumption and that limiting the reactive power of the capacitor to 5% of the apparent power of the load presents shortcomings. The results also show that setting the inductance L of the filter to L maxi and the capacitor C from 35 × C maxi to 400 × C maxi gives voltage and current THDs that meet the 519 IEEE-2014 standards.