Bidirectional Isolated Ripple Cancel Triple Active Bridge DC-DC Converter

To achieve a highly reliable DC distribution microgrid network, a bidirectional isolated ripple cancel triple active bridge (TAB) converter is proposed in this paper. In a conventional full-bridge TAB converter, the DC-link capacitors suffer from high ripple current, which significantly reduces their lifetime. To solve this issue, the proposed converter can reduce the ripple current to nearly zero by adding the clamping capacitors as an internal ripple-cancellation circuit topology. In addition, the proposed converter inherits the advantages of the conventional full-bridge TAB converter such as a wide range of soft switching and bidirectional power conversion. This makes it easier to replace the conventional full-bridge TAB converters. Finally, a 1 kW prototype was built to demonstrate its feasibility. In the experiment, the ripple current reduced to nearly zero (0.16 A) under 400 V/400 V/400 V and rated power 1 kW operating conditions. The proposed converter could be used to make highly reliable and efficient DC distribution microgrid as a power router.