Novel current inverter fully digitally controlled using SLCMC

Abstract

This paper introduces the design of a PWM power inverter as a source of sinusoidal current with a new closed loop current control. The control of the PWM applies the concept of instantaneous next step compensation in order to keep the average current constant through the main power. This method consists in collecting a sample of the line current and based on it, to estimate the upper and lower limits which are compared with the inverter's output current, in order to keep constant the frequency and the average current supplied by the inverter. The presented current power inverter is fully digitally controlled, using FPGA and VHDL technology. The method presents advantages to operate in high constant switching frequencies, improving the energy quality, and can be also powered by renewed unregulated energy sources, generating as result stable energy without pollution.