Fault Diagnosis of Isolated Bidirectional DC/DC Converter with Triple Phase-Shift Control

Isolated bidirectional dc/dc converters (IBDDCs) are widely used in the renewable energy systems such as solar energy and wind power as the power interfaces. Dual active bridge (DAB) converters show many advantages compared with other IBDDCs, such as high power density and easy in control implementation. Nowadays, many advanced controls with multiple phase-shift variables such as triple phase-shift (TPS) control have been proposed to improve the efficiency for a wider output power range. In order to ensure the system reliability, the fault diagnosis is essential to identify the faulty devices quickly and avoid the system collapse. In this paper, three common operation modes are analyzed and an open-circuit diagnosis strategy is proposed for DAB converters under the advanced TPS control. Main simulation and experimental results are provided to validate the proposed fault diagnosis method.