Analysis of Intermittent Control for Triple Active Bridge Converter to Suppress Cross-current

Reactive power is transmitted between the power supplies connected with a three-winding transformer of Triple Active Bridge DC/DC converter controlled with conventional phase-shift control. This paper proposes a novel control method based on intermittent control to reduce the cross-current that causes reactive power transmission. In the proposed method, by intermittently turning off all gates of the active bridge connected to the power supply, the remaining two active bridges operate equivalently to Dual Active Bridge DC/DC converter. This method can reduce the reactive power, especially under the conditions where the power distribution of the power supplies is different. Also, this paper describes the experimental results of a 2 kW prototype TAB converter to verify the validity of the proposed method. As a result, it was confirmed that the entire power conversion efficiency was improved by up to 2.5 pt due to suppression of the cross-current.