Open-circuit fault diagnosis of power tubes in power converter of dual three-phase starter-generator system

The aerospace dual three-phase permanent magnet assisted synchronous reluctance starter-generator system’s power converter had an open-circuit fault diagnosis issue. To address this, a single-phase open-circuit fault diagnosis and localization method for power tubes based on the bus voltage and z₁-z₂ coordinate system current was proposed. Firstly, the starter-generator and power converter model were established by using the vector space decomposition method. Next, using this model, the single-phase double-tube open-circuit and single-phase single-tube open-circuit fault characteristics represented in the power converter’s DC bus voltage and z₁-z₂ coordinate system current trajectory were examined. A single-phase single-tube open circuit and single-phase double-tube open circuit fault diagnosis and location method based on z₁-z₂ coordinate system current and DC bus voltage was proposed to detect the occurrence of faults and determine the fault location. The experimental platform ultimately confirmed the method’s efficacy. The experimental findings show that the technique is capable of identifying and diagnosing power converter single-phase power tube open-circuit failures. This in turn provides important guidance for fault-tolerant operation after the fault occurs.