QPR-Based EMS Experimental Platform Design

In the metallurgical industry, electromagnetic stirring technology is used to drive molten metal flow by means of non-contact electromagnetic forces, which places high demands on current control accuracy. To address the steady-state error associated with conventional control strategies, a quasi-proportional resonant (QPR) control method is introduced in this study to achieve high-precision tracking of the fundamental current. To verify the effectiveness of the proposed method, a current closed-loop control device based on a three-phase inverter system is constructed, and an experimental teaching platform for electromagnetic stirring is established. Experimental results show that, under different set conditions, the corresponding current output can be achieved and stable tracking of the reference current can be maintained, with a steady-state error of approximately 1%, thereby confirming the effectiveness of the proposed method. While retaining the key physical and control characteristics of electromagnetic stirring, the platform can also be used for related experimental teaching, which is helpful for understanding the mechanism and control method of electromagnetic stirring.