Parallel Operation of Switching Regulators

Abstract

The switching regulators are complex structures with many parts and, consequently, relatively low intrinsic reliability. In critical applications redundancy is employed to improve the reliability. Two main methods can be distinguished. The first is based on the redundancy of different components in a single supply [1], and the second makes use of a redundant number of smaller single supplies connected in parallel [2]. The first method is justifiable only in exceptional applications and mainly in high-power supplies. The second approach is more flexible and offers important economic advantages. A large number of identical supplies means that mass-production methods can be employed, system maintenance is simplified, and systems for different power requirements can be readily constituted. The economic advantages are the highest in the case of truly identical, autonomous sources that do not need special control units or master-slave distinction.