Increasing Energy Efficiency With Fuzzy Logic Control in FPGA-Based Electromagnetic Stirrer

Abstract

In this study, a new field-programmable gate array (FPGA)-based electromagnetic stirrer system was developed allowing mixing on a single axis, and the energy efficiency of the system was increased with fuzzy logic control. The electromagnetic stirrer system was designed with three phases and each phase is fed with pulsewidth modulation (PWM) voltage with 120° phase difference. Ranked control of phases in the system used the FPGA structure in the myRIO® embedded system to determine the PWM signal production, increase intervals for phase frequencies, and rotation rate of the magnetic stir bar. In the system, to increase the energy efficiency with fuzzy logic control, the ARM® microcontroller structure in the myRIO® embedded system was used. Programming of the myRIO® embedded system was provided through the graphic-based LabVIEW <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> software. In situations where the system is operated with 100% duty cycle, the force affecting the magnetic stir bar should be continuous and have fixed value until the next phase change. As a result, the magnetic stir bar performs more than 120° rotation and a braking effect of the force is observed. To resolve this situation, fuzzy logic control ensured operation of a different duty cycle without loss of speed of the stir bar. Thus, the energy efficiency of the system was increased with lower current and lower stimulation duration. Within the scope of this article, the experimental results obtained about the structure, control, and energy efficiency of the electromagnetic stirrer system are discussed in detail.