Daikin Industries, Ltd.

Akiko Sera

Morimitsu Sekimoto

Takurou Ogawa

Eiji Tooyama

The voltage detection circuit () is a voltage divider circuit including a plurality of resistances (toandto) and detects voltages (Vac, Vac) correlating with a power source voltage (Vin) of the AC power source (). The calculation unit () obtains the across voltage (VL) of the reactor () using detection results (Vac, Vac) of the voltage detection circuit (), and estimates a power source current (Iin) based on the across voltage (VL). The calculation unit () corrects gains of the detection results (Vac, Vac) so that a value correlating with an average value per predetermined time period of the estimated power source current (Iin) matches a value correlating with an average value per the predetermined time period of a current (Iinv) downstream of the capacitor (), and obtains the across voltage (VL) using the detection results (Vac, Vac).

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Osaka, Japan

Akiko Sera