Electrical behaviour of a power unit at the limits of the nominal range

The aim of this paper is to present the practical behaviour of a power device at the limit of the operational nominal range. The extreme states under analysis are created through supplying the unit with either minimal voltage and maximum load, or maximum voltage and minimal load. Special aspects of the test-procedure needed to increase the dynamic performance of the 18-kW Power Supply Unit are also underlined. The solid state power device under analysis is able to generate up to 2000 Amps at 28Vdc in compliance with ripple and dynamic specifications required by industrial customers. The innovative character of the paper resides in explaining the way in which certain measures are to be taken in order to reduce the harmonics and ripple values under extreme operation conditions. At the end of the contribution, complementary investigations are described, other than those provided by international standards, and which are necessary to completely fulfill the customer specifications.