CPC Definition - Subclass H02P

Last Updated Version: 2017.08
CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
Definition statement

This place covers:

Arrangements for

  • starting,
  • regulating,
  • electronically commutating,
  • braking,

or otherwise controlling:

  • motors,
  • generators,
  • dynamo-electric converters, clutches, brakes, gears,
  • transformers,
  • reactors or choke coils, of the types classified in the relevant subclasses, e.g. H01F, H02K.
References
Limiting references

This place does not cover:

Arrangements for merely turning on an electric motor to drive a machine or device, e.g.: vacuum cleaner, vehicle starter motor

A47L 9/28, F02N 11/00

Hybrid vehicle, conjoint control, arrangements for mounting

B60K, B60W

Arrangements for controlling electric generators for charging batteries

H02J 7/00

Arrangements for starting, regulating, electronically commutating, braking, or otherwise controlling electric machines not otherwise provided for, e.g. machines using piezo-electric effects

H02N

Informative references

Attention is drawn to the following places, which may be of interest for search:

Curtain

A47H

Hand hammers, drills

B25D 17/00

Printers

B41J

Power steering

B42D 5/00

Heating cooling ventilating

B60H 1/00

Electrically propelled vehicles, current collector, maglev

B60L

Lighting

B60Q 1/00

Electric circuits for vehicle

B60R, H02J

Wiper control

B60S 1/00

Marine

B63H

Elevator

B66B

Washing machines, household appliances

D06F 39/00

Sliding roof, power window

E05F

Gas turbine

F02C

Starting of engine with electric motor

F02N 11/00

Windmills

F03D

Pumps, compressors

F04B

Motor cooling

F04D

Structure of the mechanical brake

F16D

Air-conditioning

F24F

Refrigeration

F25B

Measuring arrangements

G01B 7/00

Electromagnetic actuators

G02B 26/00

Safety, control principles

G05B 9/00

Position control, servos

G05B 19/00

Structure of the mechanical speed regulator

G05D

Control of linear speed, control of angular speed; control of acceleration or deceleration

G05D 13/00

Systems for regulating electric or magnetic variables using transformers, reactors or choke coils

G05F

Cooling fans for computers

G06F 1/00

Data storage device (hard disk CD, DVD BlueRay...)

G11B

Structure of the variable resistor

H01C

Magnets, inductances or transformers structurally associated with motors, generators, dynamo-electric converters, transformers, reactors or choke coils

H01F

Structure of the starter switch

H01H

Emergency protective arrangements with automatic interruption of supply

H02H

Dynamo-electric machines structurally associated with motors, generators, dynamo-electric converters, transformers, reactors or choke coils

H02K

Apparatus for conversion between AC and AC, AC and DC or 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

H02M

Automatic control, starting, synchronisation, or stabilisation of generators of electronic oscillations or pulses

H03L

Housing, cooling of housing

H05K

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Control

influencing a variable in any way, e.g. changing its direction or its value (including changing it to or from zero), maintaining it constant, limiting its range of variation;

Regulation

maintaining a variable at a desired value, or within a desired range of values, by comparison of the actual value with the desired value.

Arrangements for starting electric motors or dynamo-electric converters (starting of synchronous motors with electronic commutators except reluctance motors, H02P 6/20, H02P 6/22; starting dynamo-electric motors rotating step by step H02P 8/04; vector control H02P 21/00)
References
Limiting references

This place does not cover:

Starting of synchronous motors with electronic commutators except reluctance motors

H02P 6/20, H02P 6/22

Starting dynamo-electric motors rotating step by step

H02P 8/04

Vector control

H02P 21/00

{Protection against "no voltage condition"}
Definition statement

This place covers:

Arrangements or measures for starting a motor when the power re-establishes after a power failure, e.g. when the motor does not automatically starts turning.

{Restarting, e.g. after power failure}
Definition statement

This place covers:

In particular restarting before the motor has stopped.

Manually-operated on/off switch controlling relays or contactors operating sequentially for starting a motor (sequence determined by power-operated multi-position switch H02P 1/08)
References
Limiting references

This place does not cover:

Sequence determined by power-operated multi-position switch

H02P 1/08

Switching devices centrifugally operated by the motor
Definition statement

This place covers:

Repulsion start induction motor (RS-IM):

An alternating-current motor that starts as a repulsion motor; at a predetermined speed the commutator bars are short-circuited to give the equivalent of a squirrel-cage winding for operation as an induction motor with constant-speed characteristics.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Starting an individual polyphase induction motor

H02P 1/26

for starting an individual dc motor
Definition statement

This place covers:

  • Starting of DC motors supplied with a DC voltage, whereby the motor is seen as an independent block not being further elaborated.
  • Starting of commutated motors
  • Starting of fan motors for a PC, also being supplied with DC
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Starting of a commutator motor supplied with AC

H02P 1/24

Computer fans

G06F 1/20

by progressive reduction of resistance in series with armature winding
Definition statement

This place covers:

The resistance may be an actual resistor or it could also be a semiconductor operating in its linear region.

References
Limiting references

This place does not cover:

PWM controlled semiconductors

H02M 3/00

for starting an individual ac commutator motor (starting of ac/dc commutator motors H02P 1/18)
Definition statement

This place covers:

In this group is for starting a commutator motor supplied by AC.

References
Limiting references

This place does not cover:

Starting of ac/dc commutator motors

H02P 1/18

for starting an individual polyphase induction motor
Definition statement

This place covers:

Repulsion start induction motor (RS-IM):

An alternating-current motor that starts as a repulsion motor; at a predetermined speed the commutator bars are short-circuited to give the equivalent of a squirrel-cage winding for operation as an induction motor with constant-speed characteristics.

Relationships with other classification places

The polyphase refers to the supply. An induction motor having main and auxiliary windings could be considered as a polyphase motor, but not within the meaning of H02P 1/26. They are classified in H02P 1/42 because they are supplied by a single phase power supply which supplies the main and auxiliary windings.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Repulsion start induction motor (RS-IM)

H02P 1/12

{Means for starting or running a triphase motor on a single phase supply}
Definition statement

This place covers:

Other means than an inverter

by progressive increase of voltage applied to primary circuit of motor
Definition statement

This place covers:

Other means than an inverter.

by progressive increase of frequency of supply to primary circuit of motor
Definition statement

This place covers:

Other means than an inverter.

by progressive reduction of impedance in secondary circuit
Definition statement

This place covers:

The resistance may be an actual resistor or it could also be a semiconductor operating in its linear region.

References
Limiting references

This place does not cover:

PWM controlled semiconductors

H03M 3/00

by pole-changing
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Pole changing for purposes other then starting

H02P 25/20

for starting an individual single-phase induction motor {(H02P 27/04 takes precedence)}
References
Limiting references

This place does not cover:

Using variable-frequency supply voltage, e.g. inverter or converter supply voltage

H02P 27/04

Informative references

Attention is drawn to the following places, which may be of interest for search:

Running of a single phase induction motor

H02P 25/04

{by using a specially adapted frequency converter}
Definition statement

This place covers:

Any typical frequency converter can be used to start from almost DC to nominal speed without modifications. These documents are not to be classified in this group except in the case where special measures are integrated with the sole purpose of starting.

for starting an individual synchronous motor {(H02P 27/04 takes precedence)}
References
Limiting references

This place does not cover:

Using variable-frequency supply voltage, e.g. inverter or converter supply voltage

H02P 27/04

by pole-changing
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Pole changing for purposes other then starting

H02P 25/20

by changing over from asynchronous to synchronous operation (H02P 1/48 takes precedence)
References
Limiting references

This place does not cover:

Starting an individual synchronous motor by pole-changing

H02P 1/48

Pole changing for purposes other then starting

H02P 25/20

Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters (stopping of synchronous motors with electronic commutators except reluctance motors, H02P 6/24; stopping dynamo-electric motors rotating step by step H02P 8/24; vector control H02P 21/00)
References
Limiting references

This place does not cover:

Stopping of synchronous motors with electronic commutators except reluctance motors,

H02P 6/24

Stopping dynamo-electric motors rotating step by step

H02P 8/24

Arrangements for controlling dynamo-electric brakes or clutches

H02P 15/00

Vector control

H02P 21/00

Electrodynamic brake systems for vehicles in general

B60L 7/00

Dynamic electric resistor braking

B60L 7/02

Dynamic electric regenerative braking

B60L 7/10

Eddy-current braking

B60L 7/28

Means for stopping or slowing by a separate brake, e.g. friction brake, eddy-current brake (brakes F16D, H02K 49/00)
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

for stopping or slowing a dc motor
Definition statement

This place covers:

DC motors, i.e. a motor supplied with a DC voltage, whereby the motor is seen as an independent block not further elaborated. Typically this is a commutated motor, however e.g. a fan motor for a PC is also supplied with DC and therefore the starting of a PC fan motor is also classified here.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Commutator motor supplied with AC

H02P 3/18

by short-circuit or resistive braking
Definition statement

This place covers:

Arrangements where energy is not regenerated but lost in resistors or in the impedances of the motor.

by regenerative braking
Definition statement

This place covers:

Arrangements or measures where the energy is regenerated, e.g. kinetic energy is reused by sending it back to the supply or stored in an energy buffer.

for stopping or slowing an ac motor
Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

AC motor

a motor supplied with an AC voltage, whereby the motor is seen as an independent block not further elaborated

by short-circuit or resistive braking
Definition statement

This place covers:

Arrangements where energy is not regenerated but lost in resistors or in the impedances of the motor.

Arrangements specially adapted for regulating or controlling the speed or torque of electric motors that can be connected to two or more different electric power supplies (vector control H02P 21/00)
References
Limiting references

This place does not cover:

Starting

H02P 1/00

Stopping or slowing

H02P 3/00

Vector control

H02P 21/00

Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors (H02P 6/04, H02P 8/40 take precedence)
References
Limiting references

This place does not cover:

Arrangements for controlling or regulating speed or torque of two or more synchronous motors, or motors with electronic commutators

H02P 6/04

Arrangements for controlling two or more stepping motors

H02P 8/40

Informative references

Attention is drawn to the following places, which may be of interest for search:

Starting

H02P 1/00

Stopping

H02P 3/00

Synchronous motors or other dynamo-electric motors with electronic commutators in dependence on the rotor position

H02P 6/00

Motors rotating step by step

H02P 8/00

Vector control

H02P 21/00

using differential movement of the two motors, e.g. using differential gearboxes
Definition statement

This place covers:

Differential gearboxes, where the output speed or phase represents the difference in speeds or phase.

using equalising lines, e.g. rotor and stator lines of first and second motors
Definition statement

This place covers:

Arrangements, wherein the rotor and stator lines of first motor are coupled in parallel with the rotor and stator lines of second motor.

Direct ratio control
Definition statement

This place covers:

Providing control for a first motor which switches a second motor on during a limited portion of one revolution, in a fixed or predetermined ratio of movement, e.g. 120 degrees of 360 degrees.

additionally providing control of relative angular displacement
Definition statement

This place covers:

Not only the speed is equalized but also the phase, e.g. newspaper printing presses where a phase difference results in paper jams.

controlling combinations of dc and ac dynamo-electric motors (H02P 5/46 takes precedence)
Definition statement

This place covers:

Arrangement for controlling both a DC motor supplied with a DC voltage and an AC motor supplied with an AC voltage, whereby the DC motor or AC motor is seen as an independent load.

References
Limiting references

This place does not cover:

Speed regulation of two or more dynamo-electric motors in relation to one another

H02P 5/46

Informative references

Attention is drawn to the following places, which may be of interest for search:

Commutator motors supplied with AC

H02P 5/74

Special rules of classification

A fan motor for a PC supplied with DC is also classified here.

controlling two or more dc dynamo-electric motors (H02P 5/46, H02P 5/60 take precedence)
Definition statement

This place covers:

Arrangement for controlling two or more DC motors supplied with a DC voltage, whereby the motor is seen as an independent load.

References
Limiting references

This place does not cover:

For speed regulation of two or more dynamo-electric motors in relation to one another

H02P 5/46

Controlling combinations of dc and ac dynamo-electric motors

H02P 5/60

Informative references

Attention is drawn to the following places, which may be of interest for search:

Commutator motor supplied with AC

H02P 5/74

Special rules of classification

A fan motor for a PC supplied with DC is also classified here.

controlling two or more ac dynamo-electric motors (H02P 5/46, H02P 5/60 take precedence)
Definition statement

This place covers:

Arrangement for controlling two or more AC motors supplied with an AC voltage, whereby the motor is seen as an independent load.

References
Limiting references

This place does not cover:

Speed regulation of two or more dynamo-electric motors in relation to one another

H02P 5/46

Controlling combinations of dc and ac dynamo-electric motors

H02P 5/60

Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor (vector control H02P 21/00)
Definition statement

This place covers:

Arrangements for controlling synchronous motors with electronic commutators where commutation is done in dependence on the rotor position, or other dynamo-electric motors with electronic commutators where commutation is done in dependence on the rotor position; Electronic commutators therefore

Brushless DC motors, e.g. BLDC motors, BL motors, electronically commutated motors, ECMs.

References
Limiting references

This place does not cover:

Vector control

H02P 21/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Motors rotating step by step

H02P 8/00

Other aspects of synchronous motors

H02P 25/022

Control of linear AC synchronous motors

H02P 25/06

Reluctance motors

H02P 25/08

Special rules of classification

Group H02P 6/26 takes precedence over groups H02P 6/04 - H02P 6/24 and H02P 6/28 -H02P 6/34.

Arrangements for controlling or regulating the speed or torque of more than one motor (H02P 6/10 takes precedence)
References
Limiting references

This place does not cover:

Arrangements for providing reduced torque ripple; arrangements for controlling torque ripple

H02P 6/10

Arrangements for controlling the speed or torque of a single motor (H02P 6/10, H02P 6/28 take precedence)
References
Limiting references

This place does not cover:

Arrangements for controlling the torque ripple

H02P 6/10

Arrangements for controlling the current

H02P 6/28

Informative references

Attention is drawn to the following places, which may be of interest for search:

Controlling commutation

H02P 6/15

Arrangements for controlling torque ripple, e.g. providing reduced torque ripple
Definition statement

This place covers:

Control of torque ripple by controlling current wave shape, e.g. by using trapezoidal current.

Relationships with other classification places

The source of the torque ripple is commutation in this group. Reducing is done e.g. by controlling with trapezoidal current or other waveforms.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Reduction by changing commutation time

H02P 6/15

Any other source for reduction in torque ripple

H02P 29/50

Controlling commutation time
Definition statement

This place covers:

Delaying or advancing the moment of commutation of the electronic commutators from the time at which the commutation would have occurred based solely on the position of the rotor.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Change in current for reducing torque ripple

H02P 6/10

Circuit arrangements for detecting position
Definition statement

This place covers:

All circuits and methods which detect the rotor position inside the motor (or outside if the rotor is mounted on the outside and the stator on the inside).

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Detecting rotor position in synchronous AC motors

H02P 25/026

Position control outside the motor e.g. position of elements which are externally connected to the motor

G05B 19/00

Structural arrangement of position sensors associated with brushless motors or generators

H02K 29/06

without separate position detecting elements
References
Limiting references

This place does not cover:

Circuit arrangements for detecting position

H02P 6/16

using inductance sensing, e.g. pulse excitation
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Current being modulated, e.g. by a high frequency component

H02P 6/18

Arrangements for starting (H02P 6/08 takes precedence)
References
Limiting references

This place does not cover:

Controlling speed or torque of a single motor

H02P 6/08

Informative references

Attention is drawn to the following places, which may be of interest for search:

Starting in a selected direction

H02P 6/22

Open loop start
Definition statement

This place covers:

Starting without feedback from the position detection, e.g. when back emf is too low.

in a selected direction of rotation
Definition statement

This place covers:

Starting without a movement in the wrong direction e.g. for hard disks spindle motor.

Arrangements for controlling current (H02P 6/10 takes precedence)
References
Limiting references

This place does not cover:

Arrangements for reducing or controlling torque ripple

H02P 6/10

Arrangements for controlling the direction of rotation (H02P 6/22 takes precedence)
Definition statement

This place covers:

A direct link between the Hall sensors and the switching transistors enables a brushless motor to turn only in one direction and an additional circuit for enabling the brushless motor to run in both directions of rotation.

References
Limiting references

This place does not cover:

Arrangements for starting in a selected direction of rotation

H02P 6/22

Arrangements for regulating or controlling the speed or torque of electric DC motors
Definition statement

This place covers:

Circuitry or apparatus for regulating or controlling the speed or torque of electrical DC motors, e.g. brushed commutator motors, homopolar motors or a ball bearing motors.

The DC motor can be supplied by an AC voltage or AC current.

There are three types of connections used for DC electric commutator motors: series, shunt and compound.

An armature generally refers to one of the two principal electrical components of an electromechanical machine–generally in a motor or generator, but it may also mean the pole piece of a permanent magnet or electromagnet, or the moving iron part of a solenoid or relay.

The other component is simply to create a magnetic field, or a magnetic flux, for the armature to interact with, so this component can comprise either permanent magnets, or electromagnets formed by a conducting coil.

The armature, in contrast, must carry current so it is always a conductor or a conductive coil, oriented normal to both the field and to the direction of motion, torque (rotating machine), or force (linear machine). The armature's role is twofold. The first is to carry current crossing the field, thus creating shaft torque in a rotating machine or force in a linear machine. The second role is to generate an electromotive force (EMF).

Other DC motors are:

  • A homopolar motor, which is an electric motor that works without the need for a commutator, by rotating along a fixed axis that is parallel to the external magnetic field produced by a permanent magnet. The name homopolar indicates that the electrical polarity of the motor does not change, i.e. that it does not require commutation. Such motors necessarily have a single-turn coil, which restricts their practical applications, since they must be used with low voltages and produce relatively small torques.
  • A ball bearing motor, which is an electric motor that consists of two ball-bearing-type bearings, with the inner races mounted on a common conductive shaft, and the outer races connected to a high current, low voltage power supply.
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Starting

H02P 1/00

Stopping

H02P 3/00

Synchronous motors or other dynamo-electric motors with electronic commutators in dependence on the rotor position

H02P 6/00

Motors rotating step by step

H02P 8/00

Vector control

H02P 21/00

{using a periodic interrupter, e.g. Tirrill regulator}
Definition statement

This place covers:

Tirrill regulator: A device for regulating the voltage of a generator, in which the field resistance of the exciter is short-circuited temporarily when the voltage drops (source: McGraw-Hill Dictionary of Scientific & Technical Terms).

of voltage applied to the armature with or without control of field {Ward-Leonard}
Definition statement

This place covers:

A Ward Leonard drive is a high-power amplifier in the multi-kilowatt range, built from rotating electrical machinery. A Ward Leonard drive unit consists of a motor and generator with shafts coupled together. The motor, which turns at a constant speed, may be AC or DC powered. The generator is a DC generator, with field windings and armature windings. The input to the amplifier is applied to the field windings, and the output comes from the armature windings. The amplifier output is usually connected to a second motor, which moves the load, such as an elevator. With this arrangement, small changes in current applied to the input, and thus the generator field, result in large changes in the output, allowing smooth speed control. Armature voltage control only controls the motor speed from zero to motor base speed. If higher motor speeds are needed the motor field current can be lowered, however by doing this the available torque at the motor armature will be reduced. Another advantage for this method is that the speed of the motor can be controlled in both directions of rotation. (From Wikipedia).

using multi-position switch, e.g. drum, controlling motor circuit by means of relays (H02P 7/24, H02P 7/30 take precedence)
References
Limiting references

This place does not cover:

Using discharge tubes or semiconductor devices

H02P 7/24

Using magnetic devices with controllable degree of saturation, i.e. transductors

H02P 7/30

using multi-position switch, e.g. drum, controlling motor circuit by means of pilot-motor-operated multi-position switch or pilot-motor-operated variable resistance (H02P 7/24, H02P 7/30 take precedence)
References
Limiting references

This place does not cover:

Using discharge tubes or semiconductor devices

H02P 7/24

Using magnetic devices with controllable degree of saturation, i.e. transductors

H02P 7/30

the DC motor being operated in four quadrants
Special rules of classification

Group H02P 7/281 takes precedence over groups H02P 7/282 - H02P 7/298.

using variable impedance
Definition statement

This place covers:

The use of a transistor or FET in linear mode (non switching)

with on-off control between two set points, e.g. controlling by hysteresis
Definition statement

This place covers:

Using a Schmitt trigger with two thresholds.

using phase control (H02P 7/295 takes precedence)
References
Limiting references

This place does not cover:

Of the kind having a thyristor or the like in series with the power supply and the motor

H02P 7/295

of the kind having a thyristor or the like in series with the power supply and the motor
Definition statement

This place covers:

Electronic switches that do not extinguish automatically.

using armature-reaction-excited machines, e.g. metadyne, amplidyne, rototrol
Definition statement

This place covers:

Rotating amplifiers, e.g. metadyne, amplidyne, rototrol, magnicon and magnavolt.

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Metadyne, Amplidyne

The Metadyne and Amplidyne are special-purpose DC generators historically used as high power electro-mechanical amplifiers in control systems. In use, such machines are driven at constant speed by a motor. The electrical output is varied by control of field excitation, as in a Ward-Leonard system. The Metadyne and the Amplidyne include an arrangement of cross-connected brushes on one axis and a further set of brushes on a perpendicular axis. This arrangement allows the machine to provide very high gain, that is, large changes of output may be controlled by small changes in the controlling field current

A rototrol (American Westinghouse Co.)

The rototrol is a two-stage machine with static and dynamic characteristics similar to those of the Amplidyne. The Rototrol may also be operated as a three-stage machine (also known as a Magnicon) in which the output is further used to excite a pole winding.

Source:

“Rotating amplifiers: The amplidyne, metadyne, magnicon and magnavolt and their use in control systems” by M. G. Say.

“Direct current machines for control systems” by Arnold Tustin metadyne, amplidyne, rototrol are now obsolete technology. Modern electronic devices for controlling power in the kilowatt range include MOSFET and IGBT devices.

using Ward-Leonard arrangements
Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Ward-Leonard system

a method of controlling the speed and direction of rotation of a DC motor by varying and if necessary reversing its armature voltage. A DC generator provides the variable armature supply. The output of the generator is controlled by control of its field current.

Ward-Leonard drive

a high-power amplifier in the multi-kilowatt range, built from rotating electrical machinery. A Ward-Leonard drive unit consists of a motor and generator with shafts coupled together. The motor, which turns at a constant speed, may be AC or DC powered. The generator is a DC generator, with field windings and armature windings. The input to the amplifier is applied to the field windings, and the output comes from the armature windings. The amplifier output is usually connected to a second motor, which moves the load, such as an elevator. With this arrangement, small changes in current applied to the input, and thus the generator field, result in large changes in the output, allowing smooth speed control. Armature voltage control only controls the motor speed from zero to motor base speed. If higher motor speeds are needed the motor field current can be lowered, however by doing this the available torque at the motor armature will be reduced. Another advantage for this method is that the speed of the motor can be controlled in both directions of rotation.

Armature

a rotor which carries a winding connected to a commutator

Arrangements for controlling dynamo-electric motors of the kind having motors rotating step by step (vector control H02P 21/00)
Definition statement

This place covers:

Stepper motors have typically a large number poles which results in a large number of steps, and use permanent magnets resulting in high cogging torque and therefore in a large holding torque, even when the motor is not energized. The motor's position can be controlled precisely without any feedback mechanism (Open-loop control).

References
Limiting references

This place does not cover:

Vector control

H02P 21/00

Control or stabilisation of current
Definition statement

This place covers:

Control of current to increase commutation speed through the inductive windings, e.g. by measuring the coil current and generating a PWM controlled current or e.g. by applying a first higher voltage and a thereafter a lower voltage.

Arrangements for controlling speed or speed and torque (H02P 8/12, H02P 8/22 take precedence)
References
Limiting references

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Using two level supply voltage

H02P 8/12

Control of step size; Intermediate stepping, e.g. microstepping

H02P 8/22

Reducing energy dissipated or supplied
Definition statement

This place covers:

e.g. by lowering the current to the minimum required to hold the position or by increasing the current when a step is required in particular using feedback to determine the movement.

Shaping of pulses, e.g. to reduce torque ripple
References
Limiting references

This place does not cover:

Reducing overshoot

H02P 8/32

Control of step size; Intermediate stepping, e.g. microstepping
Definition statement

This place covers:

Control of step size, including half step.

Arrangements for stopping (H02P 8/32 takes precedence)
References
Limiting references

This place does not cover:

Holding position when stopped

H02P 8/32

Monitoring operation (H02P 8/36 takes precedence)
References
Limiting references

This place does not cover:

Protection against faults

H02P 8/32

Protection against faults, e.g. against overheating, step-out; Indicating faults (emergency protective arrangements with automatic interruption of supply H02H 7/08)
References
Limiting references

This place does not cover:

Emergency protective arrangements with automatic interruption of supply

H02H 7/08

Arrangements for controlling electric generators for the purpose of obtaining a desired output (Ward-Leonard arrangements H02P 7/34; vector control H02P 21/00; feeding a network by two or more generators H02J; for charging batteries H02J 7/14)
References
Limiting references

This place does not cover:

Ward-Leonard arrangements

H02P 7/34

Vector control

H02P 21/00

Feeding a network by two or more generators

H02J

For charging batteries

H02J 7/14

{Means for protecting the generator by using control (H02H 7/06 takes precedence; control effected upon generator excitation circuit to reduce harmful effects of overloads or transients H02P 9/10)}
References
Limiting references

This place does not cover:

Emergency protective arrangements with automatic interruption of supply

H02H 7/06

{Control circuits for doubly fed generators}
Definition statement

This place covers:

Typically the rotor is moved by an external force and the rotor current is controlled such that a desired output voltage is achieved without an additional converter at the power output stage. The generator has typically two electrical connections and one mechanical input.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

by variation of field (H02P 9/08, H02P 9/10 take precedence)
References
Limiting references

This place does not cover:

Control of generator circuit during starting or stopping of driving means

H02P 9/08

Control effected upon generator excitation circuit to reduce harmful effects of overloads or transients, e.g. sudden application of load, sudden removal of load, sudden change of load

H02P 9/10

due to variation of make-to-break ratio of intermittently-operating contacts, e.g. using Tirrill regulator
Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Tirrill regulator

A device for regulating the voltage of a generator, in which the field resistance of the exciter is short-circuited temporarily when the voltage drops (source: McGraw-Hill Dictionary of Scientific & Technical Terms).

using discharge tubes or semiconductor devices (H02P 9/34 takes precedence)
References
Limiting references

This place does not cover:

Using magnetic devices with controllable degree of saturation in combination with controlled discharge tube or controlled semiconductor device

H02P 9/34

{controlling voltage (H02P 9/302 takes precedence)}
References
Limiting references

This place does not cover:

Brushless excitation

H02P 9/302

using magnetic devices with controllable degree of saturation (H02P 9/34 takes precedence)
References
Limiting references

This place does not cover:

Using magnetic devices with controllable degree of saturation in combination with controlled discharge tube or controlled semiconductor device

H02P 9/34

to obtain desired frequency without varying speed of the generator
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Control circuits for doubly fed generators

H02P 9/007

Arrangements for obtaining a constant output value at varying speed of the generator, e.g. on vehicle (H02P 9/04 - H02P 9/46 take precedence)
References
Limiting references

This place does not cover:

Control effected upon non-electric prime mover and dependent upon electric output value of the generator (effecting control of the prime mover in general, see the relevant class for such prime mover)

H02P 9/04

Using magnetic devices with controllable degree of saturation in combination with controlled discharge tube or controlled semiconductor device

H02P 9/34

Informative references

Attention is drawn to the following places, which may be of interest for search:

For the electrical supply of for the functioning of the battery or the electrical generator

B60R 16/03

Starter - generator

F02N 11/04

Balancing the load in a network (e.g. switching in extra loads like the airconditioning pump)

H02J 1/14

For charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle

H02J 7/14

Arrangements for controlling dynamo-electric converters (starting H02P 1/00; stopping or slowing H02P 3/00; vector control H02P 21/00; feeding a network in conjunction with a generator or another converter H02J)
References
Limiting references

This place does not cover:

Starting

H02P 1/00

Stopping

H02P 3/00

Synchronous motors or other dynamo-electric motors with electronic commutators in dependence on the rotor position

H02P 6/00, H02P 6/32

Vector control

H02P 21/00

Feeding a network in conjunction with a generator or another converter

H02J

Special rules of classification

Dynamo-electric converters are rotating machines whose purpose is not to provide mechanical power to loads but to convert one type of electric current into another, for example DC into AC. They are multi-field single-rotor devices with two or more sets of rotating contacts (either commutators or slip rings, as required), one to provide power to one set of armature windings to turn the device, and one or more attached to other windings to produce the output current. The rotary converter can directly convert, internally, any type of electric power into any other. This includes converting between direct current (DC) and alternating current (AC), three phase and single phase power, 25 Hz AC and 60 Hz AC, or many different output voltages at the same time. The size and mass of the rotor was made large so that the rotor would act as a flywheel to help smooth out any sudden surges or dropouts in the applied power. (source Wikipedia) Dynamo-electric converters are now obsolete technology. Modern electronic devices for controlling power in the kilowatt range include MOSFET and IGBT devices.

Arrangements for controlling transformers, reactors or choke coils, for the purpose of obtaining a desired output (regulation systems using transformers, reactors or choke coils G05F; transformers H01F; feeding a network in conjunction with a generator or a converter H02J; control or regulation of converters H02M)
References
Limiting references

This place does not cover:

Regulation systems using transformers, reactors or choke coils

G05F

Transformers

H01F

Feeding a network in conjunction with a generator or a converter

H02J

Control or regulation of converters

H02M

Arrangements for controlling dynamo-electric brakes or clutches (controlling speed of dynamo-electric motors by means of a separate brake H02P 29/04, vector control H02P 21/00 {see provisionally also H02K 49/00 and H02P 29/0022})
References
Limiting references

This place does not cover:

Vector control

H02P 21/00

Controlling speed of dynamo-electric motors by means of a separate brake

H02P 29/04

Arrangements for controlling dynamo-electric gears (vector control H02P 21/00)
References
Limiting references

This place does not cover:

Vector control

H02P 21/00

Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
Special rules of classification

When classifying in this group, classification should also be made under H02P 25/00 when the method of control is characterised by the kind of motor being controlled. Classification should also be made under H02P 27/00 when the method of control is characterised by the kind of supply voltage of the motor being controlled.

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Vector control

a method of controlling the speed of a three phase ac motor by varying its power supply in accordance with a mathematical model of the machine flux. Stator currents are measured and transformed into a complex current space vector, allowing control of flux and torque. The vector components are then transformed to a rotating coordinate system and voltages calculated in this system are generated by an inverter and applied to the motor.

{Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Control strategies in general

H02P 23/0004

specially adapted for very low speeds
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Arrangements for starting

H02P 6/20

Determining the initial rotor position

H02P 21/32

Arrangements or methods for the control of AC motors specially adapted for very low speeds

H02P 23/03

specially adapted for damping motor oscillations, e.g. for reducing hunting
Definition statement

This place covers:

Synchronous Motor having an inherent instability, e.g. when it is used to drive a high inertia load. The motor ideally should spin at a constant angular velocity, but it instead sporadically oscillates about synchronous speed. This phenomenon is known as ‘hunting’. This problem produces current ripples at the motor’s electrical terminals and induces noise.

Rotor flux based control involving the use of rotor position or rotor speed sensors
Definition statement

This place covers:

  • Reference frame conversion being based in the rotor
  • Control is based on the rotor flux.
Stator flux based control involving the use of rotor position or rotor speed sensors
Definition statement

This place covers:

  • Reference frame conversion being based in the rotor
  • Control is based on the stator flux.
Estimation of constants, e.g. the rotor time constant
Definition statement

This place covers:

Estimation of changes in constants, e.g. temperature related changes in winding resistance.

Determining the initial rotor position (H02P 21/34 takes precedence)
References
Limiting references

This place does not cover:

Arrangements for starting

H02P 21/34

Informative references

Attention is drawn to the following places, which may be of interest for search:

Position detection in general

H02P 6/16

Arrangements or methods for the control of AC motors characterised by a control method other than vector control
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Starting

H02P 1/00

Stopping

H02P 3/00

Two or more motor

H02P 5/00

Synchronous motors or other dynamo-electric motors with electronic commutators in dependence on the rotor position

H02P 6/00

DC motors

H02P 7/00

Special rules of classification

When classifying in this group, subject matter relating to vector control should also be made under H02P 21/00. Classification should also be made under H02P 25/00 when the method of control is characterised by the kind of motor being controlled. Classification should also be made under H02P 27/00 when the method of control is characterised by the kind of supply voltage of the motor being controlled.

{Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage

H02P 23/14

Control of angular speed of one shaft by controlling the prime mover

H02P 23/16

{Characterised by the use of a particular software algorithm}
Definition statement

This place covers:

A software algorithm that is only suitable in motor control which enables the implementation of a strategy in a processor (minimalising computing steps).

The motor parameters are stored in the in memory chip located in (or in the proximity of e.g. installed coder) the motor identifying the motor.

specially adapted for damping motor oscillations, e.g. for reducing hunting
Definition statement

This place covers:

For attenuating the rotational velocity fluctuations of AC motors which spin at non-constant angular velocity.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Arrangements for controlling or reducing torque ripple in synchronous motors or electronically commutated motors

H02P 6/10

Control of reluctance motors

H02P 25/08

Motor oscillations that are synchronous to the motor position

H02P 29/50

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

hunting

Hunting occurs when a synchronous motor is used to drive a high inertia load and sporadically oscillates about synchronous speed which induces noise.

Controlling by adding a dc current (dc current braking H02P 3/24)
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

DC current braking

H02P 3/24

Controlling the angular speed of one shaft (H02P 23/18 takes precedence)
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Control of angular speed together with angular position or phase

H02P 23/18

Controlling the angular speed together with angular position or phase
Definition statement

This place covers:

The speed and the phase (or position) of a rotating shaft are both controlled to reach both a predetermined reference signal

{of one shaft without controlling the prime mover}
Definition statement

This place covers:

By acting on a device that is not the driving motor; for example, by acting on a brake.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Suitable for AC and DC motors

H02P 29/0022

{of one shaft by controlling the prime mover}
Definition statement

This place covers:

By acting on the supply of the motor that drives the shaft.

Power factor control [PFC]
Definition statement

This place covers:

Special control of the motor, e.g. by adapting the voltage and the phase/frequency fed to the motor.

Direct torque control [DTC] or field acceleration method [FAM]
Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

DTC

Direct torque control is one method used in variable frequency drives to control the torque (and thus finally the speed) of three-phase AC electric motors. This involves calculating an estimate of the motor's magnetic flux and torque based on the measured voltage and current of the motor.

Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Starting

H02P 1/00

Stopping

H02P 3/00

Two or more motor

H02P 5/00

Synchronous motors or other dynamo-electric motors with electronic commutators in dependence on the rotor position

H02P 6/00

DC motors

H02P 7/00

Stepping motors

H02P 8/00

Special rules of classification

When classifying in this group, subject matter relating to vector control should also be classified under H02P 21/00. Classification should also be made under H02P 27/00 when the method of control is characterised by the kind of supply voltage of the motor being controlled.

thereby detecting the rotor position
Definition statement

This place covers:

Circuit or methods which controls and detects the rotor position of the AC motor.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

The motor being controlled based on the determined position

H02P 6/00

with four quadrant control
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Head positioning in hard disks

G11B

Voice coil motors (voice coil motors driven by DC power H02P 7/025)
References
Limiting references

This place does not cover:

Voice coil motors driven by DC

H02P 7/025

Informative references

Attention is drawn to the following places, which may be of interest for search:

Driving or moving heads in hard disks

G11B

Arrangements for increasing the switching speed from one coil to the next one
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Direct torque control

H02P 23/30

Arrangements for reducing torque ripple

H02P 25/098

Sensorless control (direct torque control H02P 23/30)
References
Limiting references

This place does not cover:

Direct torque control

H02P 23/30

Arrangements for reducing torque ripple
Definition statement

This place covers:

Reduction of torque ripple or ‘cogging’ torque arising from the construction of the motor, wherein the reluctance of the magnetic circuit changes as the motor revolves, for example due to differing rotor and stator saliencies.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

AC motor control arrangements, other than vector control, specially adapted for damping motor oscillations or reducing hunting

H02P 23/04

Reduction of harmonics

H02P 29/50

Commutator motors, e.g. repulsion motors
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

DC motors

H02P 7/00

{Repulsion motors}
Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Repulsion motor

a type of electric motor for use on alternating current. It was formerly used as a traction motor for electric trains but has been superseded by other types of motors and is now only of historical interest. Repulsion motors are classified under Single Phase motors. In magnetic repulsion motors the stator windings are connected directly to the ac power supply and the rotor is connected to commutator and brush assembly, similar to that of a DC armature.

with shiftable brushes
Definition statement

This place covers:

Shiftable brushes allow control of speed and/or torque

Universal motors (H02P 25/12 takes precedence)
References
Limiting references

This place does not cover:

Motors with shiftable brushes

H02P 25/12

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Series-wound motor

a universal motor when it has been designed to operate on either AC or DC power. It can operate well on AC because the current in both the field and the armature (and hence the resultant magnetic fields) will alternate (reverse polarity) in synchronism, and hence the resulting mechanical force will occur in a constant direction of rotation.

{whereby the speed is regulated by using a periodic interrupter (H02P 25/30 takes precedence)}
References
Limiting references

This place does not cover:

Motor being controlled by a control effected upon an ac generator supplying it

H02P 25/30

for pole-changing
Definition statement

This place covers:

Pole changing for starting an individual polyphase induction motor

H02P 1/38

Pole changing for starting an individual synchronous motor

H02P 1/46

Arrangements or methods for the control of AC motors characterised by the kind of supply voltage (of two or more motors H02P 5/00; of synchronous motors with electronic commutators H02P 6/00; of DC motors H02P 7/00; of stepping motors H02P 8/00)
References
Limiting references

This place does not cover:

Two or more motor

H02P 5/00

Synchronous motors or other dynamo-electric motors with electronic commutators in dependence on the rotor position

H02P 6/00

Controlling the speed or torque of DC motors

H02P 7/00

Controlling stepping motors

H02P 8/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Starting

H02P 1/00

Stopping

H02P 3/00

Special rules of classification

When classifying in this group, subject matter relating to vector control should also be classified under H02P 21/00. Classification should also be made under H02P 25/00 when the method of control is characterised by the kind of motor being controlled.

If the supply is not particularly adapted for the control of a motor than it should not be classified here e.g. a variable voltage supply is suitable for a DC motor however it is suitable for various loads and therefore should be classified in a general voltage supply group e.g. H02M or G05B Only when the supply is exclusively for the control of AC motors these groups are used e.g. because control is influenced in function of a motor parameter (e.g. speed, torque, position, motor parameters etc)

using AC supply for both the rotor and the stator circuits, the frequency of supply to at least one circuit being variable
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Doubly fed motors

H02P 6/005

Doubly fed generators

H02P 9/007

using dc to ac converters or inverters (H02P 27/05 takes precedence)
References
Limiting references

This place does not cover:

AC supply for both rotor and stator circuits, the frequency of supply to at least one circuit being variable

H02P 27/05

using bang-bang controllers
Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Bang–bang controller (on–off controller)

is also known as a hysteresis controller, is a feedback controller that switches abruptly between two states

pulsing by guiding the flux vector, current vector or voltage vector on a circle or a closed curve, e.g. for direct torque control
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Direct torque control per se

H02P 23/30

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

DTC

Direct torque control is one method used in variable frequency drives to control the torque (and thus finally the speed) of three-phase AC electric motors. This involves calculating an estimate of the motor's magnetic flux and torque based on the measured voltage and current of the motor.

using ac to ac converters without intermediate conversion to dc (H02P 27/05 takes precedence)
References
Limiting references

This place does not cover:

Using ac supply for both rotor and stator circuits, the frequency of supply to at least one circuit being variable

H02P 27/05

Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors (arrangements for starting electric motors H02P 1/00; arrangements for stopping or slowing electric motors H02P 3/00; control of motors that can be connected to two or more different electric power supplies H02P 4/00; regulating or controlling the speed or torque of two or more electric motors H02P 5/00; vector control H02P 21/00)
References
Limiting references

This place does not cover:

Starting

H02P 1/00

Stopping

H02P 3/00

Control of motors that can be connected to two or more different voltage or current supplies

H02P 4/00

Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors

H02P 5/00

Vector control

H02P 21/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Emergency protective circuit arrangements for electric machines involving automatic switching

H02H 7/00

Emergency protective circuit arrangements for electric machines for limiting excess current or voltage without disconnection

H02H 9/00

{Control of angular speed of one shaft without controlling the prime mover}
Definition statement

This place covers:

The (prime mover) motor is supplied with a constant power supply. Some means connected (mechanically) with the motor and the load influences the speed.

Providing protection against overload without automatic interruption of supply (protection against faults of stepper motors H02P 8/36)
Definition statement

This place covers:

Motor regulation or control guarding against excessive voltage or amperage while power is maintained, e.g. protection against broken phase or power surge/failure

References
Limiting references

This place does not cover:

Protection for stepper motors

H02P 8/36

Informative references

Attention is drawn to the following places, which may be of interest for search:

Protection during start

H02P 1/022

Generator overload and transient protection

H02P 9/10

Emergency protective arrangements with automatic interruption of supply

H02H 7/0833

Emergency protective circuit arrangements for limiting excess current or voltage without disconnection, in general

H02H 9/00

Protection of inverter circuit

H02M 1/32

Reduction of harmonics
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

From commutation

H02P 6/00

Motor oscillation

H02P 23/04

In Reluctance motors

H02P 25/08

EMI interference reduction on the converter side

H02M

Controlling or determining the temperature of the motor or of the drive (H02P 29/02 takes precedence)
References
Limiting references

This place does not cover:

Protection against overload

H02P 29/02

Informative references

Attention is drawn to the following places, which may be of interest for search:

Protection against faults of stepper motors

H02P 8/36

Motor parameter estimation for vector control

H02P 21/14

AC motor parameter estimation

H02P 23/14

Measuring temperature

G01K 7/42

{the rotor having permanent magnets (H02P 29/67 takes precedence)}
References
Limiting references

This place does not cover:

By back-EMF evaluation to obtain the motor temperature

H02P 29/67

{Controlling or determining the motor temperature by back electromotive force [back-EMF] evaluation}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Back-EMF based rotor position determination

H02P 6/182