Reliability estimation of UPS systems: Boolean truth table method

This paper investigates the application of the Boolean truth table modelling method in estimating the reliability parameters such as the system's failure rates and mean time between failures (MTBF), for the uninterruptible power supply (UPS) systems. All possible state combinations (operating and failed states) of the major components in the UPS systems were listed and their effects on overall system were studied. The method was applied to five UPS configurations and the results obtained were compared to the results from other reliability estimation method such as the reliability block diagram (RBD) method and field data estimation method