Desenvolvimento e implementação de um conversor microcontrolado com corrente média de saída CC regulada para processos industriais

Abstract

The development of a high current rectifier controlled by a microcontroller and based on ANSI 45 configuration is presented in this work. At first, different topologies which can provide high rectified current are presented. From the analysis and the simulation studies of the topologies, was selected the ANSI 45 configuration, mainly due to its advantages compared to the three-phase Graetz configuration. The operation stages analysis, the current rectifier components design, and the microcontroller electronic interface circuits were performed. A control algorithm of the rectified current was developed in assembler using a PI controller. It controls the rectifier output current by adjusting the thyristor’s firing angle. A laboratory prototype of 6kW, with 300A and 20V of maximum values, was implemented. Comparisons between experimental and simulation results demonstrate that the mathematical model describe the rectified current behavior in an appropriate form. Experimental results at steady state, dynamic behavior and efficiency of the prototype are presented and discussed.