Standby uninterruptible power supply non-delay synchronous switching circuit

The utility model discloses a standby uninterruptible power supply non-delay synchronous switching circuit which is applied to the non-delay synchronous switching between a standby AC inverter control circuit output and a power grid power supply output. The standby AC inverter control circuit output outputs voltage through an output filter inductor and an output filter capacitor. The synchronous switching circuit comprises a power grid AC synchronous sampling circuit. The power grid output is used as the input of the power grid AC synchronous sampling circuit. The output of the power grid AC synchronous sampling circuit is used as the input of the standby AC inverter control circuit. A switch circuit is arranged between the power grid power supply and the standby AC inverter control circuit. The switch circuit is driven through a driving circuit. According to the utility model, completely uninterruptible power supply like online UPS is realized; the work efficiency is improved; and the standby uninterruptible power supply non-delay synchronous switching circuit has the advantages of use safety and good energy saving effect.