US 12,244,255 B2
Electric motor drive device and refrigeration cycle application device
Koyo Shimizu, Tokyo (JP); and Shinya Toyodome, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 18/253,976
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Feb. 25, 2021, PCT No. PCT/JP2021/007170
§ 371(c)(1), (2) Date May 23, 2023,
PCT Pub. No. WO2022/180746, PCT Pub. Date Sep. 1, 2022.
Prior Publication US 2023/0412107 A1, Dec. 21, 2023
Int. Cl. H02P 27/08 (2006.01)
CPC H02P 27/08 (2013.01) 7 Claims
OG exemplary drawing
 
1. An electric motor drive device comprising:
a booster circuit to boost a voltage value of a bus voltage to be applied to a direct-current bus;
an inverter to apply an alternating-current voltage having a variable frequency and a variable voltage value to an electric motor, the bus voltage being applied to the inverter;
a connection switching device to switch a connection state of a winding of the electric motor; and
a control device to control operations of the booster circuit, the inverter, and the connection switching device, and perform zero current control to control the inverter such that a current flowing through the electric motor or the connection switching device is zero, wherein
when operating the connection switching device to switch the connection state, the control device performs the zero current control after stopping a boosting operation of the booster circuit.