Bi-directional TRIAC fault-protection technique for Z-source half-bridge converter-fed AC motor Drives

With higher demand for power electronic converters in single-phase drive systems, the concern for fault-tolerant schemes has risen in the past decade. Also, the demand for Impedance(Z)-source converters, facilitating single-stage power conversion with high voltage gain, has increased for induction motor drive systems. This paper presents an efficient two TRIAC fault-protection technique for the impedance-source half-bridge converter-fed induction motor drive system. The study is analyzed thoroughly under pre-fault and post-fault conditions and a comparative analysis is presented in this paper. Simulation circuits with relevant harmonic spectra are assessed. From the detailed analysis, it is found that the occurrence of faults increases harmonic distortion to a high level, making the drive system ineligible for operation. The proposed fault-protection technique proves to be an efficient topology in maintaining continuous power flow during faults.