High voltage Buck converter topology for common mode voltage reduction

A new DC buck converter topology to actively reduce common mode voltage applied to the load is presented in chi paper, The supply is designed to interface universal input DC-DC power supplies to a rectified 480Vac (700Vdc) bus,]By minimizing, the common mode voltage produced, the size and cost of the passive filter elements san be significantly reduced, In the topology presented, an additional switching device to cancel the common node voltage augments the traditional buck converter, Canceling the common mode voltage reduces tile EMI filter requirements. It is shown that the switching losses remain unchanged while the voltage rating oi the switching devices can be reduced, By using de-rated devises, the cost of the converter is reduced.