Power management system and method

The invention discloses a power management system. The power management system is applied to a smart home system, the smart home system comprises a plurality of terminals, a central controller and a terminal controller, the plurality of terminals and the central controller are sequentially connected in parallel to a mains supply bus, the terminal controller is connected with the central controller and the terminals, and the power management system comprises a data transmission bus and a power-off protection unit. The power-off protection unit comprises a first port, a second port, a third port, an overvoltage and overcurrent protection module, a processing module, a switching circuit and a storage module, wherein the first port and the second port are connected to a mains supply bus, the third port is connected to a data transmission bus, the overvoltage and overcurrent protection module is connected between the first port and the second port, the processing module is connected with the overvoltage and overcurrent protection module, the switching circuit is connected with the first port and the processing module, and the storage module is connected with the processing module and the third port and is connected with the switching circuit. Equipment operation information loss and voltage and current impact in the storage module when the power supply is suddenly powered off are prevented, and the working safety of the intelligent home system is ensured.