US 12,476,568 B2
Drive circuit for a brushless motor
Stephen Greetham, Gloucester (GB); and Maté Horvát, Swindon (GB)
Assigned to Dyson Technologies Limited, Wiltshire (GB)
Appl. No. 18/038,184
Filed by Dyson Technology Limited, Wiltshire (GB)
PCT Filed Nov. 15, 2021, PCT No. PCT/GB2021/052950
§ 371(c)(1), (2) Date May 22, 2023,
PCT Pub. No. WO2022/117991, PCT Pub. Date Jun. 9, 2022.
Claims priority of application No. 2019089 (GB), filed on Dec. 3, 2020.
Prior Publication US 2023/0421085 A1, Dec. 28, 2023
Int. Cl. H02P 6/06 (2006.01); H02M 1/08 (2006.01); H02P 6/26 (2016.01); H02P 27/04 (2016.01)
CPC H02P 27/04 (2013.01) 19 Claims
OG exemplary drawing
 
1. A drive circuit for a brushless motor, the drive circuit comprising:
a converter for connection to a phase winding of the motor, the converter comprising a plurality of switches; and
a controller for controlling the switches to configure the converter in a plurality of configurations comprising:
a first configuration in which the converter is controlled to permit current flow through the phase winding in a first direction and in a second opposite direction; and
a second configuration in which the converter is controlled to permit current flow through the phase winding in the first direction and is prevented from flowing through the phase winding in the second direction,
wherein the controller comprises an input for receiving a signal indicative of current in the converter, and the controller configures the converter from the first configuration to the second configuration in response to a characteristic of the current; and
wherein each of the switches has four states: (i) ON in which the switch is conductive in both a first direction and a second direction, (ii) D1 in which the switch is conductive in the first direction and non-conductive in the second direction, (iii) D2 in which the switch is non-conductive in the first direction and conductive in the second direction, and (iv) OFF in which the switch is non-conductive in both the first direction and the second direction;
in the first configuration, the states of a pair of switches are controlled to the ON state and the states of another pair of switches are controlled to the OFF state; and
in the second configuration, the states of a pair of switches are controlled to one of the D1 and D2 states, and the states of another pair of switches are controlled to the OFF state.