Apparatus and method for flux management in impedance isolation single conversion(ZISC) based UPS system

An apparatus for flux management in an impedance isolation single conversion (ZISC) based uninterruptible power supply (UPS) system, the apparatus comprising:

• a first determining unit configured to determine a first offset flux on a series reactor in the ZISC based UPS system when power quality events occur in a grid connected to the ZISC based UPS system and the ZISC based UPS system operates in a grid-connected mode;
• a first resetting unit configured to provide synthetic impedance damping to the series reactor to reset the first offset flux;
• a second determining unit configured to determine a second offset flux on a transformer in the ZISC based UPS system when the ZISC based UPS system operates in the grid-connected mode or an island mode;
• and
• a second resetting unit configured to reset the second offset flux in response to a magnitude of the second offset flux exceeding a flux magnitude limit.