Three-phase electric energy meter circuit

The invention discloses a three-phase electric energy meter circuit which comprises a three-phase switch power supply circuit, a communication circuit, a digital quantity output circuit, an MCU circuit, an analog switch circuit, a digital isolation circuit, an optocoupler circuit and a three-phase metering circuit. The three-phase switching power supply circuit comprises a protection circuit 1, a three-phase full-bridge rectification circuit, a protection circuit 2, a PN8145T circuit, a secondary feedback circuit, a switching transformer, an output circuit VO1, an output circuit VO2 and an output circuit VO3. According to the three-phase switching power supply circuit based on the PN8145T power supply chip, the number of components is reduced, a two-stage protection circuit is provided at the power supply input end, and the reliability of the power supply circuit is improved; electrical isolation between the three-phase metering circuit and the MCU circuit is realized through the digital isolation circuit, th