# US 2023/0411978 A1 · Battery pack identification in power tool

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- Number: US 2023/0411978 A1
- Document ID: US20230411978A1
- Status: Published application
- Kind: A1
- Application number: 17/842,955
- Filed: 2022-06-17
- Published: 2023-12-21
- Earliest claimed: 2022-06-17
- Assignees: Black & Decker Inc.
- Applicants: Black & Decker Inc.
- Inventors: Mehdi RAMEZANI
- Web page: https://patentgrep.com/patent/US20230411978A1

## CPC

- H02J 7/82: Control of state of charge [SOC]
- B25F 5/00: Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
- H02J 7/927: {with introduction of pulses during the charging process}
- H02K 5/04: Casings or enclosures characterised by the shape, form or construction thereof
- H02K 11/0094: {Structural association with other electrical or electronic devices}
- H02M 7/53876: {based on synthesising a desired voltage vector via the selection of appropriate fundamental voltage vectors, and corresponding dwelling times}
- H02P 6/16: Circuit arrangements for detecting position
- H02P 6/185: using inductance sensing, e.g. pulse excitation
- H02P 21/14: Estimation or adaptation of machine parameters, e.g. flux, current or voltage
- H02M 7/53871: {with automatic control of output voltage or current}
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- B25F: COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR {(machines or arrangements of machines for performing specified combinations of different metal-working operations not covered by a single other subclass B23P23/00 and subgroups)}
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS

## Abstract

A power tool is provided including: a housing including a battery receiving portion configured to receive a removeable power tool battery pack and a motor housing; a brushless direct-current (BLDC) motor disposed within the motor housing, the motor including a stator and a rotor; a power switch circuit disposed between the battery receiving portion and the motor; and a controller that controls a switching operation of the power switch circuit to regulate a supply of power from the battery pack to the motor. At tool start-up, the applies a series of voltage pulses to the motor and measures a corresponding series of motor phase current values to identify an initial position of the rotor relative to the stator. Further, the controller identifies at least one of an impedance or a capacity of the battery pack as a function of the motor phase current values.

## Claims

### Claim 1

A power tool comprising:
a housing including a battery receiving portion configured to receive a removeable power tool battery pack and a motor housing;
a brushless direct-current (BLDC) motor disposed within the motor housing, the motor including a stator and a rotor;
a power switch circuit disposed between the battery receiving portion and the motor; and
a controller configured to control switching operation of the power switch circuit to regulate a supply of power from the battery pack to the motor, wherein at tool start-up, the controller is configured to apply a plurality of voltage pulses to the motor and measure a corresponding plurality of motor phase current values to identify an initial position of the rotor relative to the stator,
the controller being further configured to identify at least one of an impedance or a capacity of the battery pack as a function of the plurality of motor phase current values.

### Claim 2 (depends on 1)

The power tool of claim 1, where the motor includes three phases and the plurality of phase current values includes six current signals.

### Claim 3 (depends on 1)

The power tool of claim 1, wherein the controller is configured to measure a bus voltage of a bus line provided between the battery receiving portion and the power switch circuit, and calculate a battery identifier as a function of a sum of the plurality of phase current values divided by the bus voltage.

### Claim 4 (depends on 1)

The power tool of claim 1, wherein the controller is further configured to apply a high magnitude voltage pulse to a sector of rotor orientation corresponding to the initial position of the rotor relative to the stator and measure a corresponding high-magnitude current value.

### Claim 5 (depends on 4)

The power tool of claim 4, wherein the controller is further configured to monitor a bus voltage drop on a bus line provided between the battery receiving portion and the power switch circuit, and identify at least one of the impedance or the capacity of the battery pack as a function of the high-magnitude current value and the bus voltage drop.

### Claim 6 (depends on 1)

The power tool of claim 1, wherein the controller is configured to calculate a battery identifier as a function of the plurality of motor phase current values, and identify the battery pack as a first type of battery pack having a first capacity if the battery identifier is below a threshold value and as a second type of battery pack having a second capacity if the battery identifier is above the threshold value.

### Claim 7 (depends on 6)

The power tool of claim 6, wherein the controller is configured to set the threshold value based on the initial position of the rotor relative to the stator.

### Claim 8

A power tool comprising:
a housing including a battery receiving portion configured to receive a removeable power tool battery pack and a motor housing;
a brushless direct-current (BLDC) motor disposed within the motor housing, the motor including a stator and a rotor;
a power switch circuit disposed between the battery receiving portion and the motor;
a bus line provided between the battery receiving portion and the power switch circuit; and
a controller configured to control switching operation of the power switch circuit to regulate a supply of power from the battery pack to the motor, wherein at tool start-up, the controller is configured to apply a plurality of voltage pulses to the motor and measure a corresponding plurality of motor phase current values to identify an initial position of the rotor relative to the stator,
the controller being further configured to apply a high magnitude voltage pulse to a sector of rotor orientation corresponding to the initial position of the rotor relative to the stator, measure a corresponding high-magnitude current value, and identify at least one of an impedance or a capacity of the battery pack as a function of the high-magnitude current value.

### Claim 9 (depends on 8)

The power tool of claim 8, wherein the controller is further configured to monitor a bus voltage drop on the bus line, and identify at least one of the impedance or the capacity of the battery pack as a function of the high-magnitude current value and the bus voltage drop.

### Claim 10 (depends on 8)

The power tool of claim 8, wherein the controller is further configured to identify at least one of the impedance or the capacity of the battery pack as a function of the plurality of phase current values.

### Claim 11 (depends on 10)

The power tool of claim 10, wherein the controller is configured to measure a bus voltage of the bus line and calculate a battery identifier as a function of the high-magnitude current value, the plurality of phase current values, and the bus voltage.

### Claim 12 (depends on 8)

The power tool of claim 8, wherein the controller is configured to calculate a battery identifier as a function of the plurality of motor phase current values, and identify the battery pack as a first type of battery pack having a first capacity if the battery identifier is below a threshold value and as a second type of battery pack having a second capacity if the battery identifier is above the threshold value.

### Claim 13 (depends on 12)

The power tool of claim 12, wherein the controller is configured to set the threshold value based on the initial position of the rotor relative to the stator.