A novel algorithm for open switch fault detection and fault tolerant control of interleaved DC-DC boost converters

This paper presents a novel algorithm for fault diagnosis and fault tolerant control of interleaved boost converters (IBCs) in the presence of single or double simultaneous open-circuit faults (OCFs) in power switches. An innovative diagnosis signal (recorded by a cheap current sensor) will be introduced whose waveform mainly depends on the healthy or faulty condition of the converter. Since the diagnosis signal is periodic in the steady-state operation of the converters, its Fourier Series coefficients, together with the duty cycle of the converter are used as distinguishing features for fault diagnosis of the OCFs in the converter. The well-known Kalman filter is utilized for robust estimation of the Fourier-based features. Finally, the modulation of the remaining healthy phases is rearranged in a way that the pre-fault performance recovers. The proposed algorithm is verified in a laboratory four-phase IBC setup in which the experimental results show its satisfactory performance. Also, the structure of the proposed method is straightforward and can be implemented in the same microcontroller which is used for voltage and current regulation of the converter.