NO-DELAY SYNCHRONOUS SWITCHING CIRCUIT AND METHOD FOR BACKUP-TYPE UNINTERRUPTIBLE POWER SYSTEM

摘要

A no-delay synchronous switching circuit and method for a backup-type uninterruptible power system (UPS), which are applied to the no-delay synchronous switching between a standby AC inversion control circuit output and a grid power output. An output of a standby AC inversion control circuit outputs a voltage through an output filter inductor (T2) and an output filter capacitor (C1). The synchronous switching circuit comprises a grid AC synchronous sampling circuit, an output of the grid serving as an input of the grid AC synchronous sampling circuit, and an output of the grid AC synchronous sampling circuit serving as an input of the standby AC inversion control circuit. Switch circuits (M1 and M2) are arranged between the grid power and the standby AC inversion control circuit. The switch circuits are driven by a drive circuit. The circuit is adopted to realize complete uninterrupted power supply of an on-line UPS, and increase the work efficiency, and is safe to use.