Control strategy of a dual lane fault tolerant permanent magnet motor to reduce drag torque under fault condition

Patent metadata

Field	Value
Publication number	US-10320183-B2
Application number	US-201615229442-A
Country	US
Kind code	B2
Filing date	Aug 5, 2016
Priority date	Aug 10, 2015
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A motor drive circuit comprising two or more inverters to provide current to a permanent magnet motor. Each inverter includes a respective switch arm comprising one or more switches for each phase of the motor to be driven. The motor drive circuit includes means for detecting a switch short circuit for any switch within one of the inverters and means for determining the speed of the motor. The motor drive circuit further includes a controller configured to short circuit each switch arm of the inverter containing the switch short circuit if the motor speed exceeds a predetermined threshold, but not if the motor speed does not exceed the predetermined threshold.

First claim

The invention claimed is:

1. A motor drive circuit comprising:
two or more inverters to provide current to a dual lane fault tolerant three-phase permanent magnet motor, each inverter comprising, for each phase of the motor to be driven, a respective switch arm comprising one or more switches;
means for detecting a switch short circuit for any switch within one of the inverters;
means for determining the speed of the motor; and
a controller configured, in the event a switch short circuit is detected within one of the inverters, to:
a): close all switch arms of the inverter containing the switch short circuit when the motor speed exceeds a predetermined threshold, and
b): not to close any of the switch arms not containing the short-circuited switch if the motor speed does not exceed the predetermined threshold.

2. The motor drive circuit of claim 1 , wherein each switch arm comprises two switches connected in series.

3. A method of controlling a motor drive circuit for driving a dual lane fault tolerant permanent magnet motor, the method comprising:
monitoring the motor speed of the dual lane fault tolerant permanent magnet motor;
detecting when a switch short circuit occurs in any switch in any of two inverters connected to the dual lane fault tolerant permanent magnet motor;
comparing the motor speed to a predetermined threshold;
short-circuiting all motor phases of a the dual lane fault tolerant motor connected to the inverter in response to detection of both: i) a switch short circuit in any switch in the inverter, and ii) the motor speed exceeding a predetermined threshold; and
not short-circuiting any motor phases not containing the short-circuited switch if the motor speed does not exceed the predetermined threshold.

Assignees

• Goodrich Actuation Systems Ltd

Inventors

• Benarous Maamar
• Li Jiang

Classifications

• H02H7/093 Primary

  against increase beyond, or decrease below, a predetermined level of rotational speed (centrifugal switches H01H35/10) · CPC title

• H02P29/032

  Preventing damage to the motor, e.g. setting individual current limits for different drive conditions · CPC title

• H02P27/06 Primary

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• H02H3/023

  by short-circuiting · CPC title

• H02P29/028

  the motor continuing operation despite the fault condition, e.g. eliminating, compensating for or remedying the fault · CPC title