Control device, conversion device, control method, and electricity distribution system

A conversion device comprising:

• a converter that is connected to a power generator and a storage battery and that converts DC power into AC power;
• and
• a control device that controls power to be supplied to a specific load from at least one of the converter and a commercial power supply;
• wherein
• the control device includes:
• a detection unit that determines whether the commercial power supply is in a power failure state or a power distribution state;
• and a load connection controller that switches, in accordance with a determination result of detection unit, connection between the converter and the specific load and connection between the commercial power supply and the specific load, and wherein:
• when the detection unit determines that the commercial power supply is in a power distribution state, the load connection controller causes both of the converter and the commercial power supply to be connected to the specific load;
• when the detection unit determines that the commercial power supply has made a transition from a power distribution state to a power failure state, the load connection controller causes the commercial power supply to be disconnected from the specific load while maintaining the connection between the converter and the specific load;
• and
• when the detection unit determines that the commercial power supply has made a transition from a power failure state to a power distribution state, the load connection controller causes the converter to be disconnected from the specific load and the commercial power supply to be connected to the specific load.

A power distribution system comprising:

• a power generator;
• a storage battery that stores power from at least one of the power generator and a commercial power supply;
• a converter that is connected to the power generator and the storage battery and that converts DC power into AC power;
• a control device that controls power to be supplied to a specific load from at least one of the converter and the commercial power supply;
• a switch that turns on or off connection between the converter and the commercial power supply;
• and
• a power source switching unit that selectively connects the specific load to either a first pathway branched from a point between the switch and the converter or a second pathway branched from a point between the switch and the commercial power supply, wherein
• the control device includes:
• a detection unit that determines whether the commercial power supply is in a power failure state or a power distribution state;
• and a load connection controller that controls, in accordance with a determination result of the detection unit, turning on and off of the switch and switching of the power source switching unit, and wherein:
• when the detection unit determines that the commercial power supply is in a power distribution state, the load connection controller causes the switch to be turned on and causes the power source switching unit to connect the specific load to the second pathway;
• when the detection unit determines that the commercial power supply has made a transition from a power distribution state to a power failure state, the load connection controller causes the switch to be turned off and causes the power source switching unit to connect the specific load to the first pathway;
• and
• when the detection unit determines that the commercial power supply has made a transition from a power failure state to a power distribution state, the load connection controller maintains the off state of the switch and causes the power source switching unit to connect the specific load to the second pathway.

A method of controlling power to be supplied to a specific load from at least one of a converter that has a power generator and a storage battery both connected thereto and converts DC power into AC power, and a commercial power supply, the method comprising:

• determining whether the commercial power supply is in a power failure state or a power distribution state;
• causing, when it is determined that the commercial power supply is in a power distribution state, both of the converter and the commercial power supply to be connected to the specific load;
• causing, when it is determined that the commercial power supply has made a transition from a power distribution state to a power failure state, the commercial power supply to be disconnected from the specific load while maintaining the connection between the converter and the specific load;
• and
• causing, when it is determined that the commercial power supply has made a transition from a power failure state to a power distribution state, the converter to be disconnected from the specific load and the commercial power supply to be connected to the specific load.