Two-degree-of-freedom PID digital control of a bidirectional quasi-single-stage push-pull forward high frequency link inverter

In this paper, a high performance circuit topology and control techniques are developed. The proposed bidirectional quasi-single-stage push-pull forward high frequency link inverter consists of a push-pull forward converter, a bidirectional active rectifier, an active clamp branch and a SPWM inverter bridge. In particular, a two-degree-of-freedom PID digital controller is applied to achieve high performance in both the command tracking and the load disturbance regulation. The modulation and control strategy are realized by using the TMS320LF2407A DSP and EPM7128 CPLD. The principles of circuit operation are also discussed in this paper. Theoretical analysis and experimental results indicate that the proposed topology and control scheme are promising for the applications of DC/AC power supply.