Motor drive device

Patent metadata

Field	Value
Publication number	US-9762050-B2
Application number	US-201313965266-A
Country	US
Kind code	B2
Filing date	Aug 13, 2013
Priority date	Aug 27, 2012
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A motor drive device for driving a motor, which has a plurality of winding pairs, includes a plurality of inverter units for the plurality of winding pairs. The inverter units are coupled in parallel to a power source. A plurality of capacitors provided for the plurality of inverter units, and a plurality of power relays are disposed between the power supply and the inverter units. In particular, a power relay is provided for each of the inverter units. A control unit detects a short failure of the power relay, and simultaneously turns ON the power relays that do not have a short failure. In such manner, damage to the power relays as well as damage to other electronic components of the motor driver device due to a large electric current is prevented.

First claim

What is claimed is:

1. A motor drive device for driving a motor, which has a plurality of winding pairs, the motor drive device comprising:
a plurality of inverter units for the plurality of winding pairs, the plurality of inverter units coupled to a power supply in parallel to each other;
a plurality of capacitors coupled to the plurality of inverter units;
a plurality of power relays disposed between the power supply and the plurality of inverter units;
a choke coil disposed between the power supply and the plurality of power relays; and
a control unit having a drive control unit and a failure detection unit, the driver control unit controlling a drive of the inverter units and a drive of the power relays, and the failure detection unit detecting a short failure of the power relays, wherein the drive control unit simultaneously turns ON the power relays that are detected by the failure detection unit as not having the short failure,
wherein a resistance of a wiring between a battery and a choke coil is about three to five times of a resistance of the plurality of inverter units.

2. The motor drive device of claim 1 further comprising:
a plurality of reverse connection protection relays disposed between the power relay and the plurality of inverter units, wherein
the drive control unit controls the drive of the reverse connection protection relays,
the power relay and the reverse connection protection relay are semiconductor elements having a parasitic diode, and
the parasitic diode of the reverse connection protection relay is disposed in an opposite direction relative to a direction of the parasitic diode of the power relay.

3. The motor drive device of claim 2 , wherein
the drive control unit turns OFF the reverse connection protection relay provided for the power relay that is detected by the failure detection unit as having the short failure.

4. The motor drive device of claim 1 disposed in an electric power steering apparatus.

5. The motor drive device of claim 1 , wherein the resistance of the wiring between the battery and the choke coil is about three to five times of the resistance of the plurality of inverter units, when the plurality of power relays are turned ON substantially at a same time.

Assignees

• Denso Corp

Inventors

• Uryu Nobuhiko
• Matsuda Naoki

Classifications

• H02H7/1222 Primary

  responsive to abnormalities in the input circuit, e.g. transients in the DC input · CPC title

• B62D5/046

  Controlling the motor · CPC title

• B62D5/0487

  detecting motor faults (B62D5/0496 takes precedence) · CPC title

• B62D5/0484

  for reaction to failures, e.g. limp home · CPC title

• B62D5/0403

  characterised by constructional features, e.g. common housing for motor and gear box · CPC title