Parallel operating system for uninterruptible power units

摘要

A system for operating in parallel plural non-break power units, each unit including an inverter inserted between an input power source and a parallel bus and an AC switch inserted between the bypass power source and the parallel bus and having an inverter power supply mode via the inverter and a bypass source power supply mode via the AC switch when the inverter stops. Each unit includes a switch driver for generating an AC switch driving signal in response to an inverter power supply signal based on the output signal of a sequence control circuit. Inverter mode signal output terminals are mutually connected. The switch driver generates the relevant AC switch driving signal on the basis of an inverter supply signal synthesized on a per-unit basis.