Immunity test results of a quick power failure detector of uninterruptible secondary battery system

An uninterruptible secondary battery system (USBS) consists of secondary batteries and a multi-functional power converter having plural operational modes including local load leveling and uninterruptible power supply (UPS). For the USBS, a quick power failure detector is essential for the smooth operational mode changes. However, commercial AC line voltage harmonic distortion or voltage unbalance may cause misoperation of the quick power failure detector. In this paper we present immunity test results of the USBS. The test results proved that the proposed detector has sufficient immunity to harmonic distortion and unbalance of the commercial AC line voltage.