Inversor PWM com controle por modos deslizantes em tempo discreto

Abstract

This work presents one of the most used topologies of an Uninterruptible Power Supply (UPS) with main focus to the steps of the PWM inverter and control used: Sliding Mode Control in Discrete Time. The PWM inverter with an LC filter contribute significantly to the appearance of the output voltage, thus, this work show initially the characteristics of a PWM inverter and how is generated a PWM signal through his driver. An LC filter is mathematically modeled and designed. The output voltage to be controlled passes through several blocks before being sent to processing unit, which is responsible for generating the control action. The blocks comprised of: acquisition, conditioning, conversion, processing and generation of the PWM signal are presented and modeled for computer simulation. The technique Sliding Modes Control is one of the techniques used in UPS’s. This control technique is a well-used tool in nonlinear systems with the main feature its efficiency and robustness under parametric variations. This technique was designed and implemented in discrete time to control the output voltage of a PWM inverter. The performance evaluation was conducted through computer simulations and even showed excellent response in the presence of random or periodic disturbances, as well as to load variation.