Nova concepção de barramento em corrente contínua com tensão variável para uso industrial

Abstract

DC buses and microgrids have drawn significant attention from academia due to the ease of integration of distinct sources and energy storage systems. However, most research refers to the use of DC buses for residential, datacenter, and telecommunication applications rather than industries. Most processes are controlled by AC motor supplied by the AC grid. This requires the energy supplied to the motor be twice processed leading to energy waste. In this context, this work proposes a novel approach for DC microgrids applied to industrial plants. Differently from other applications mentioned the DC bus voltage presents variable magnitude, aiming at improving energy efficiency as it has been shown through simulation, experimental results in laboratory and in a real plant. To prove the new conception here proposed an industrial process of a real machine in a large-size shoe factory is used. The induction motors of polyvinyl chloride (PVC) injection machines are supplied through an inverter which DC bus varies in the range from 530 V to 600 V. A capacitor bank is properly designed and directly connected across the DC bus and is responsible for storing the energy that would be lost during motor brakes the process. Experimental tests were carried out also in laboratory. The obtained results show that the DC bus needs no rigid control of the voltage and a reduction of up to 5.05% in energy consumption obtained during the evaluated process.