Detection of open circuit fault in battery power supply feeding permanent magnet synchronous motor

This study presents a model‐based method for detecting an open‐circuit fault in battery supply unit feeding a permanent magnet synchronous motor. Apart from the commonly present DC voltage sensor at converter's input, no additional sensors are required. As a first step, the DC supply system is modelled as a lumped parameter electric circuit. Further, a procedure for estimation of DC supply voltage based on inverter's current and open‐circuit battery voltage is proposed. A sliding mode observer is then used to obtain the actual value of open‐circuit battery voltage, required by the modelling algorithm. Consequently, an open‐circuit fault in a DC supply circuitry is determined based on the analysis of discrepancy between the estimated and measured DC supply voltage. Detection algorithm has been tested on a laboratory setup and its functionality is confirmed by experimental results.