Dual-inverter for a brushless motor

Patent metadata

Field	Value
Publication number	US-2018076745-A1
Application number	US-201715699040-A
Country	US
Kind code	A1
Filing date	Sep 8, 2017
Priority date	Sep 9, 2016
Publication date	Mar 15, 2018
Grant date	—

Abstract

A power tool is provided including: an electric brushless direct current (BLDC) motor having rotor and a stator defining phases; a power unit including a first switch circuit connected electrically between a first power supply and the motor, and a second switch circuit connected electrically between a second power supply and the motor; and a controller configured to control a switching operation of the first switch circuit and the second switch circuit to regulate a supply of power from at least one of the first power supply and/or the second power supply to the motor.

First claim

1 . A power tool comprising:
an electric brushless direct current (BLDC) motor having a rotor and a stator defining a plurality of phases; a power unit including: a first switch circuit connected electrically between a first power supply and the motor, and a second switch circuit connected electrically between a second power supply and the motor, to effectively provide a parallel connection between the first power supply and the second power supply; and a controller configured to control a switching operation of the first switch circuit and the second switch circuit to regulate a supply of power from the first power supply and the second power supply to the motor.

2 . The power tool of claim 1 , wherein the first power supply and the second power supply both comprises direct current (DC) power supplies.

3 . The power tool of claim 1 , wherein the first switch circuit and the second switch circuit both comprise a plurality of insulated-gate bipolar transistors (IGBTs) or a plurality of field-effect transistors (FETs).

4 . The power tool of claim 1 , wherein the first switch circuit and the second switch circuit are arranged to electrically isolate the first power supply from the second power supply to prevent flow of current from first power supply to the second power supply or vice versa.

5 . The power tool of claim 1 , wherein the controller is configured to control motor commutation by concurrently driving the first switch circuit and the second switch circuit using one set of drive signals.

6 . The power tool of claim 1 , wherein the stator comprises a plurality of windings associated with the plurality of phases, first switch circuit is electrically connected to a first set of stator windings of the plurality of windings, and the second switch circuit is electrically connected to a second set of stator windings of the plurality of windings.

7 . The power tool of claim 6 , wherein the first set of windings and the second set of windings are alternatingly disposed around the stator.

8 . The power tool of claim 1 , further comprising a battery selector switch disposed between the first power supply and the second switch circuit to selectively couple the first power supply to the second switch circuit when the second power supply is not present.

9 . A power tool comprising:
an electric brushless direct current (BLDC) motor having a rotor and a stator defining a plurality of phases associated with a plurality of windings; a power unit including a first switch circuit connected electrically between a first power supply and a first set of stator windings of the plurality of windings and a second switch circuit connected electrically between a second power supply and a second set of windings of the plurality of windings; and a controller configured to control a switching operation of the first switch circuit and the second switch circuit to regulate a supply of power from the first power supply and the second power supply to the motor.

10 . The power tool of claim 9 , wherein the power unit effectively provides a parallel connection between the first power supply and the second power supply.

11 . The power tool of claim 9 , wherein the first power supply and the second power supply both comprise direct current (DC) power supplies.

12 . The power tool of claim 9 , wherein the first switch circuit and the second switch circuit both comprise a plurality of insulated-gate bipolar transistors (IGBTs).

13 . The power tool of claim 9 , wherein the first switch circuit and the second switch circuit both comprise a plurality of field-effect transistors (FETs).

14 . The power tool of claim 9 , wherein the controller is configured to control motor commutation by concurrently driving the first switch circuit and the second switch circuit using one set of drive signals.

15 . The power tool of claim 9 , further comprising a battery selector switch disposed between the first power supply and the second switch circuit to selectively couple the first power supply to the second switch circuit when the second power supply is not present.

Assignees

• Black & Decker Inc

Inventors

• Cox John D

Classifications

• H02M7/53875

  with analogue control of three-phase output · CPC title

• H02P25/22

  Multiple windings; Windings for more than three phases · CPC title

• H02P6/085

  in a bridge configuration · CPC title

• H02P2209/01

  Motors with neutral point connected to the power supply · CPC title

• H02P6/14 Primary

  Electronic commutators · CPC title