Digital voltage-mode-control of a full-bridge phase-shift-modulated DC-DC converter

Voltage-mode-control of a phase-shift-modulated full-bridge DC-DC converter, using a digital Proportional-Integral (PI) controller, is described in this paper. For implementing the digital controller, a low cost 16 bit microcontroller, dsPIC30F2010, is used. External hardware requirements are quite minimum, as the microcontroller has an inbuilt PWM module and ADC. Frequency response method is employed here to directly design the digital controller. Alongside, the concern of limit cycle oscillations is addressed, while maintaining converter switching frequency and ADC resolution at comfortably high levels. Performance of the digital feedback controller is checked using a 300 W, 100 V prototype converter.