Three-phase high-frequency inverter based on DSP

LI Wei, CHEN Hui-ming

(College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)

Abstract: Aiming at the problem that it is difficult to track the load resonance frequency and system reliability is reduced due to the large difference between three-phase load because of parameter difference, a three-phase high-frequency inverter solution was proposed. The digital signal processor (DSP) TMS320F28035 was applied as the core control chip and the control strategy used the double-loop mode, including the current-loop which could effectively regulate the output current and the phase-loop which could adjust the output frequency of the inverter to achieve the effective load resonant frequency tracking. In order to overcome the problem of the system working into the capacitive state, a phase-limit loop was added, making the inverter work in inductive state, achieving the IGBT zero current switching and diode naturally current exchange to reduce switching losses, and also improving the reliability of power supply. The experimental results indicate that the scheme is simple and stable, which laying a good foundation of the related system research.