Transformer isolated, multi-output power supplies (MOPS) are useful as gate drivers auxiliary supply in multi switch conversion systems such as motor drive inverters. This work investigated the use of series resonant capacitors at the secondaries of the transformer to compensate the leakage inductance and explored the issues of cross regulation and parasitic oscillation at light load. Analytical, simulation and experimental studies, conducted in this work, showed that good overall performance can be obtained by the proposed choice of the components of the MOPS. Synopsis Transformer isolated, multi-output auxiliary power supplies (MOPS) are useful as gate drivers supply in multi switch conversion systems such as motor drive inverters. Systems based on WBG devices require low interwinding capacitance of the MOPS isolation transformers. This gives rise to large leakage inductance of the transformer which in turn results in poor load stability and cross regulation. This work investigated the use of series resonant capacitors at the secondaries of the transformer to compensate the leakage inductance and explored the issues of cross regulation and parasitic oscillation at light load. The effects of the non-idealities were investigated analytically, by simulation and experimentally. The results of these studies were used to develop recommendations for considerably improving the performance of the MOPS by proper choice of the resonant capacitors, the rectifying diodes and an LDO which dissipate rather low power.
