US 12,231,057 B2
Power conversion device for suppressing flow of short-circuit current to discharging resistor
Kentaro Shioura, Tokyo (JP); and Takeshi Yamamoto, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/905,945
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Mar. 26, 2020, PCT No. PCT/JP2020/013687
§ 371(c)(1), (2) Date Sep. 9, 2022,
PCT Pub. No. WO2021/192145, PCT Pub. Date Sep. 30, 2021.
Prior Publication US 2023/0096893 A1, Mar. 30, 2023
Int. Cl. H02J 7/00 (2006.01); H02J 7/34 (2006.01); H02M 1/12 (2006.01); H02M 7/44 (2006.01)
CPC H02M 7/44 (2013.01) [H02J 7/0063 (2013.01); H02J 7/345 (2013.01); H02M 1/126 (2013.01); H02J 2207/20 (2020.01); H02J 2207/50 (2020.01)] 18 Claims
OG exemplary drawing
 
1. A power conversion apparatus comprising:
a filter capacitor to be charged with electric power fed from a main power source;
power converting circuitry comprising primary terminals between which the filter capacitor is connected, and secondary terminals, the power converting circuitry being configured to convert the electric power fed from the main power source via the filter capacitor into electric power to be fed to a load connected to the secondary terminals, and feed the converted electric power to the load;
a power-source contactor to electrically connect the filter capacitor and the power converting circuitry to the main power source or electrically disconnect the filter capacitor and the power converting circuitry from the main power source;
a discharging circuit connected in parallel to the filter capacitor, the discharging circuit comprising:
a discharging contactor that includes an inner coil, the discharging contactor being configured to be closed in response to discharging of the inner coil and to be opened in response to energization of the inner coil; and
a capacitor discharging resistor connected in series to the discharging contactor; and
a discharge control circuit to, after opening of the power-source contactor, cause the inner coil included in the discharging contactor to be discharged and thus close the discharging contactor, thereby causing the filter capacitor to be discharged,
wherein
the discharge control circuit comprises:
a switching element to electrically connect the inner coil to a control power source or electrically disconnect the inner coil from the control power source; and
a coil discharging resistor and a control capacitor connected in series to each other, and
the coil discharging resistor and the control capacitor are connected in parallel to the inner coil.