Steady-state analysis of dual converters with circulating-current mode used in four-quadrant DC magnet power supplies

The authors present a steady-state analysis of the dual converter operating in a circulating current mode, with an output low-pass filter, in order to identify the operating conditions of the proposed power supply configuration. In the power supply configuration, interconverter inductors are used to limit the circulating current and an additional low-pass filter is required to reduce output ripple content. The operating conditions of the power supply configuration are identified by closed-form solutions of the instantaneous voltage and current waveforms. The steady-state operation is affected by the low-pass output filter and the effects are examined in terms of the inductance ratio. The effective output filter inductance is the sum of two inductances: one half of the circulating current limiting inductance and the output filter inductance. The Thevenin equivalent circuit of the dual converter with circulating current is identified