2020 | vol. 68 | nr. 1 | art. 2

Signal Analysis-based Diagnosis Method for Multi-Level Flying Capacitor Converter under Open-Circuit Fault

Thiziri BEN ALI, Abdellah KOUZOU, Ahmed HAFAIFA, Ali TETA
Multi-level inverters have become widely used in several high and medium power applications owing to their improved output voltage compared with the output voltage provided by two level inverters. However, when a fault occurs in a cell in the converter it could lead to a failure or malfunction on the application chain of the whole system. Therefore, automatic failure detection is becoming more and more essential. In this paper, a new algorithm is developed for switch open-circuit fault detection and localisation in a flying capacitor multilevel converter. The proposed algorithm is not dedicated only for the fault detection, but also for faulty switch localization. Since the output voltage of the FC converter is totally related to the control applied on the switches, the proposed technique requires only the output voltage and pulse width modulation (PWM) switching signals. A mathematical model is developed to provide a reference signal for all the considered faulty cases. Next, the faulty switch is precisely located after performing a procedure through several comparators and filters. This paper aims first to provide detailed explanation of the proposed algorithm, followed by a validation through an extensive simulation and finally the analysis of the results, which confirm the performance of the proposed technique.
Keywords: multilevel inverters, flying capacitor converter, pulse width modulation (PWM), open-circuit fault, fault detection
To cite this article: BEN ALI T., KOUZOU A., HAFAIFA A., TETA A., “Signal Analysis based Diagnosis method for Multi-level Flying Capacitor Converter under Open-Circuit Fault”, in Electrotehnica , Electronica, Automatica (EEA), 2020, vol. 68, no. 1, pp. 12-20, ISSN 1582-5175.