Parallel Operation of DC/DC Converters in Redundant Systems
16 October 1989
Many electronic systems are designed with redundant power architectures to improve overall reliability and performance. Redundant power systems (n+1 redundancy) often specify parallel operation of the power converters. A `n+1` redundant power system refers to `n+1` power converters operating with their outputs paralleled at a common voltage bus, such that `n` power converters are able to deliver the maximum required power for the system. System reliability can be increased while maintenance and repair cost can be decreased if the power converters share load current by some `Forced Load Sharing` (FLS) mechanism. This paper will examine various methods of parallel converter operation and their attendant system impact from two broad perspectives: 1) power converter design and 2) system performance. From the power converter design aspect, the overall complexity of the paralleling circuit, system reliability, and the electrical and thermal stress on the power converters for various paralleling schemes will be reviewed. Power system performance during hot plug-in, load transient, load regulation, and converter failure will also be evaluated.