Power conditioner

A power conditioner that interconnects with a power system that includes a single-phase three-wire system having first, second and third electric wires, the power conditioner comprising:

• a power converter configured to convert power received from a power generation apparatus to direct-current power;
• an inverter configured to convert the direct-current power into alternating-current power that is output to the power system;
• and
• a control unit configured to generate at least one mounting error of at least one of a first current sensor for detecting a current value of the first electric wire and a second current sensor for detecting a current value of the second electric wire,
• wherein the control unit calculates a first system power based on the current value detected by the first current sensor and a voltage between the first and third electric wires,
• wherein the control unit calculates a second system power based on the current value detected by the second current sensor and a voltage between the second and third electric wires,
• wherein the control unit generates the at least one mounting error when at least one of the calculated first and second system powers is less than zero, with the generated at least one mounting error indicating at least one of the first and second current sensors is mounted incorrectly to the single-phase three-wire system.

A method for detecting a mounting of first and second current sensors for a power conditioner interconnected with a power system that includes a single-phase three-wire system having first, second and third electric wires, the method comprising:

• converting, by a power converter, power received from a power generation apparatus to direct-current power;
• converting, by an inverter, the direct-current power into alternating-current power that is output to the power system;
• generating, by a control unit, an error signal that indicates a mounting error of at least one of the first current sensor for detecting a current value of the first electric wire and the second current sensor for detecting a current value of the second electric wire;
• generating, by the control unit, the error signal based on respective power values calculated from the current values detected by the first and second current sensors;
• and
• when the direct-current power output from the inverter varies by or more than a first threshold value during a first predetermined time period, outputting, by the control unit, the error signal if at least one of the calculated power values does not vary with a variation of the direct-current power output from the inverter during a second predetermined time period.