Power management apparatus, power management system, and power management method

A power management system, comprising:

• an image forming device installed in a room;
• a plurality of sensors of different types installed in the room separately from the image forming device;
• and
• a power management apparatus connectable to the image forming device and the sensors via one or more interface circuits and configured to:
• store in a memory a table indicating a plurality of combinations of states of the sensors, wherein each of the states is one of a high level, a low level, a transition from the high level to the low level, and a transition from the low level to the high level,
• generate first log data of the states of the sensors in a plurality of periods of a day,
• acquire, from the image forming device, second log data of operational states of the image forming device in the periods, each of the operational states being one of an ON state, an OFF state, and a power saving state,
• generate usage data that associates each of the periods with one of the operational states of the image forming device and one of the combinations indicated by the table stored in the memory,
• using the usage data, determine an expected operational state of the image forming device corresponding to a combination of current states of the sensors and a current period, and
• control a power supply to the image forming device based on the expected operational state and a current operational state of the image forming device.

A power management method for managing a power supply to an electrical device installed in a room, the method comprising:

• storing in a memory a table indicating a plurality of combinations of states of a plurality of different types of sensors installed in the room separately from the electrical device, wherein each of the states is one of a high level, a low level, a transition from the high level to the low level, and a transition from the low level to the high level;
• generating first log data of the states of the sensors in a plurality of periods of a day;
• acquiring from the electrical device second log data of operational states of the electrical device in the periods, each of the operational states being one of an ON state, an OFF state, and a power saving state;
• generating usage data that associates each of the periods with one of the operational states of the electrical device and one of the combinations indicated by the table stored in the memory;
• using the usage data, determining an expected operational state of the electrical device corresponding to a combination of current states of the sensors and a current period;
• and
• controlling the power supply based on the expected operational state and a current operational state of the electrical device.