Development and Application of the Two-Phase Orthogonal Power Supply for Electromagnetic Stirring

This paper presents a three-leg voltage-source inverter topology for two-phase orthogonal power supply used for driving electromagnetic stirring. Compared with the conventional two two-leg inverter, the three-leg structure reduced the loss of power module and switching. The improved structure has an inductor in series between two-phase orthogonal power supply and the common phase of electromagnetic stirring, which make it possible to apply deadbeat current control method to two-phase orthogonal power supply, thus the controller design is simplified, the current adjustment speed is enhanced, and the current waveform is improved. A control strategy with reactive power compensation is proposed for enhancing the utilization rate of a three-phase pulsewidth modulation (PWM) rectifier in two-phase power supply, which makes it possible that the three-phase PWM rectifier not only operating rectification status but also operating reactive power compensation status. Hence, the reactive compensation cost of enterprises will be decreased. At last, simulation and industrial application results are provided to verify the effectiveness of the proposed topology and control strategy.