US 12,270,832 B2
Device and method for diagnosing failure of inverter initial charging circuit
Jae Moon Lee, Anyang-si (KR); and Tae Suk Bae, Anyang-si (KR)
Assigned to LS ELECTRIC CO., LTD., Anyang-si (KR)
Appl. No. 17/801,413
Filed by LS ELECTRIC CO., LTD., Anyang-si (KR)
PCT Filed Jan. 7, 2021, PCT No. PCT/KR2021/000189
§ 371(c)(1), (2) Date Aug. 22, 2022,
PCT Pub. No. WO2021/172736, PCT Pub. Date Sep. 2, 2021.
Claims priority of application No. 10-2020-0022386 (KR), filed on Feb. 24, 2020.
Prior Publication US 2023/0078868 A1, Mar. 16, 2023
Int. Cl. G01R 1/20 (2006.01); G01R 31/327 (2006.01)
CPC G01R 1/203 (2013.01) [G01R 31/3278 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A device for diagnosing a failure of an inverter initial charging circuit, comprising:
a relay malfunction detector comprising a photocoupler having an input side connected in parallel to an initial charging resistor of the inverter initial charging circuit to detect a malfunction of a relay, wherein the inverter initial charging circuit includes the initial charging resistor and the relay;
a voltage detector comprising a first resistor connected in parallel with an output side of the photocoupler, a second resistor connected in series with the first resistor and a voltage measuring device measuring an output voltage applied to the first resistor and a voltage applied to a DC link capacitor, wherein the first resistor and the second resistor connected in series are connected in parallel with the DC link capacitor of an inverter, and wherein the output voltage is determined according to a ratio of resistances of the first resistor and the second resistor and to the voltage applied to the DC link capacitor; and
a controller configured to determine whether the relay malfunctions by the output voltage and the voltage applied to the DC link capacitor, wherein the controller determines that the relay has malfunctioned when the voltage applied to the DC link capacitor has been dropped and the output voltage becomes 0 after an initial charging of the inverter is completed and the inverter starts to operate.