Evaluation and Control of a High Frequency Link Inverter with Minimum RMS Current

To enhance the efficiency of the high frequency link inverter and reduce its control complexity, a minimum current root-mean-square (RMS) algorithm based on extended phase-shift modulation is proposed. First, the modulation modes of the inverter are divided, and one of them is selected as the actual operating mode. Then, the RMS current optimization equation is derived, and a simple hybrid optimization PWM modulation strategy is designed by combining it with phase shift modulation. The optimized duty cycle value can be generated by using the detected value and the data stored in the lookup table. Finally, a 500 W experimental prototype is built for verification. The results reveal that the proposed control strategy is featured by simple control and easy implementation, while achieving the minimum RMS current and improving efficiency.