Design and evaluation of digital control system for power converters at Advanced Photon Source

The DC-DC converters at the Advanced Photo Source at Argonne National Laboratory are over 15 years old. An upgrade to digital control system is being evaluated to resolve the aging and obsolescence issues. These converters supply power to electromagnets that are used to guide high energy beams. Thus a highly accurate control system is required for the DC-DC converters. This paper describes the design and evaluation of a digital control system to regulate the output current. The digital control system is proposed to replace the current analog control system thereby resolving the aging and obsolescence issues. A digital controller is first designed based on the small signal model of the converter. Experimental data of the output current is analyzed. The complete control system is then simulated and results are evaluated.