A novel P-I-D digital control FPGA for a switching power supply in HVDC system

This paper presents a novel digital P-I-D control FPGA for a switching power supply in the higher voltage direct-current (HVDC) power feeding system. At first, digital fast P control buck type converter is presented. Then, the appropriate number of sample point is determined. Then the fast P control is applied to the full bridge converter for HVDC. The acceptable delay time, with realizing superior dynamic response, is half of a switching cycle based on the appropriate number of sample points of buck converter. In the proposed method, the calculation processes of P and I-D controls are parallel. The delay time of P control is less than that of I-D control. The step change against the load will be discussed. It is revealed that the proposed circuit has the superior transient response. Then the proposed digitally controlled phase-shift full bridge dc-dc converter is verified with 800W proto type. The maximum power efficiency is about 92%. Then it is confirmed that proposed digital controlled phase-shift full bridge dc-dc converter achieves superior transient response compared to conventional one.