This paper proposes a fault tolerance control method for a three-leg two-phase inverter to secure the functional reliability of xEV components. It
diagnoses an open-switch fault with the size of the current sensed within 2 cycles in real time without applying conventional coordinate conversion
and complex formulas. The MOSFET that has failed stops operating, and another MOSFET in the same leg are set to always conduct. In the three-
leg two-phase inverter, the fault state is classified for each case in which an open-switch fault diagnosis has occurred, and the duty ratio of the A,
B, and C phases is adjusted. Through duty ratio adjustment and phase shift control for each switch of the inverter, functional reliability is secured by
supplying the same power as before the failure. The functional reliability of an inverter is verified through simulations and experimental result.