Certain aspect of the present disclosure relates to a power management system. A detection device generates detection signals based on detection of a plurality of user identification (ID) devices, and sends the detection signals to a power management controller. For each of the user ID devices being detected, the power management controller retrieves the corresponding user ID, and determines a user ID device presence event based on the received detection signals. In response to determining the user ID device presence event, the power management controller retrieves device IDs associated with the corresponding user ID of the user ID device from a database, and determine a target device based on the retrieved device IDs. Then the power management controller may power on or power off the target device based on the determined user ID device presence event and the power state of the target device.