Cooperative Patent Classification

CPC Definition - Subclass H02P

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Last Updated Version: 2016.11
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

Hybrid vehicle, conjoint control, arrangements for mounting

Arrangements for controlling electric generators for charging batteries

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

Informative references

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

Curtain

Hand hammers, drills

Printers

Power steering

Heating cooling ventilating

Electrically propelled vehicles, current collector, maglev

Lighting

Electric circuits for vehicle

Wiper control

Marine

Elevator

Washing machines, household appliances

Sliding roof, power window

Gas turbine

Starting of engine with electric motor

Windmills

Pumps, compressors

Motor cooling

Structure of the mechanical brake

Air-conditioning

Refrigeration

Measuring arrangements

Electromagnetic actuators

Safety, control principles

Position control, servos

Structure of the mechanical speed regulator

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

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

Cooling fans for computers

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

Structure of the variable resistor

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

Structure of the starter switch

Emergency protective arrangements with automatic interruption of supply

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

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

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

Housing, cooling of housing

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

Starting dynamo-electric motors rotating step by step

Vector control

{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

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Sequence determined by power-operated multi-position switch

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

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

Computer fans

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

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

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)

{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

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PWM controlled semiconductors

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

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

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

Informative references

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

Running of a single phase induction motor

{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

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

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

Pole changing for purposes other then starting

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-elecric motors rotating step by step H02P 8/24; vector control H02P 21/00)
References
Limiting references

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Stopping of synchronous motors with electronic commutators except reluctance motors,

Stopping dynamo-electric motors rotating step by step

Arrangements for controlling dynamo-electric brakes or clutches

Vector control

Electrodynamic brake systems for vehicles in general

Dynamic electric resistor braking

Dynamic electric regenerative braking

Eddy-current braking

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:

Brakes

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

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

Stopping or slowing

Vector control

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:

Starting

Stopping

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

Motors rotating step by step

Vector control

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:

In this group a DC motor is 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 although anno 2010 they are most likely BLDC. A commutator motor supplied with AC goes to H02P 5/74 and subgroups.

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

References
Limiting references

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

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

This place covers:

In this group a DC motor is 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
Limiting references

This place does not cover:

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

Controlling combinations of dc and ac dynamo-electric motors

Commutator motor supplied with AC

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

This place covers:

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

References
Limiting references

This place does not cover:

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

Controlling combinations of dc and ac dynamo-electric motors

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, EC motors

References
Limiting references

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Motors rotating step by step

Vector control

Reluctance motors

Informative references

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

Other aspects of synchronous motors

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

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Arrangements for controlling the current

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

Any other source for reduction in torque ripple

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:

Synchronous motor detecting rotor position

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

Structural arrangement of position sensors

without separate position detecting elements
References
Limiting references

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Circuit arrangements for detecting position

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

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

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

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Controlling speed or torque of a single motor

Starting in a selected direction

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

This place covers:

DC motor is typically a brushed commutator motor. 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 the field winding or field magnet. The role of the "field" component is simply to create a magnetic field (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 (from Wikipedia) A homopolar motor 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 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
Limiting references

This place does not cover:

Starting

Stopping

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

Motors rotating step by step

Vector control

{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
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Using discharge tubes or semiconductor devices

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

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

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Using discharge tubes or semiconductor devices

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

using variable impedance
Definition statement

This place covers:

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

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

an electrical machine with three, or more, brushes. It can be used as an amplifier or rotary transformer. It is similar to a third brush dynamo but much more complex, having additional regulator or "variator" windings. It is also similar to an amplidyne except that the latter has a compensating winding. The technical description is "a cross-field direct current machine designed to utilize armature reaction". A metadyne can convert a constant-voltage input into a constant current, variable voltage, output.

Amplidyne

is a special type of motor-generator which uses regeneration to increase its gain. Energy comes from the motor, and the power output is controlled by changing the field current of the generator. In a typical generator the load brushes are positioned perpendicular to the magnetic field flux. To convert a generator to an amplidyne you connect what would be the load brushes together and take the output from another set of brushes that are parallel with the field. The perpendicular brushes are now called the 'quadrature' brushes. This simple change can increase the gain by a factor of 10,000 or more.

A rototrol (American Westinghouse Co.)

is defined by the author as a machine having an initial excitation on one pair only of diametrically opposite polar projections and an output obtained from a four pole excitation with either two or three stages of amplification.

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
Special rules of classification

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)

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

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Vector control

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

Control of step size; Intermediate stepping, e.g. micro-stepping

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

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Reducing overshoot

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

This place covers:

Control of step size, including half step.

Arrangements for stopping (H02P 8/32 takes precedence)
References
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Holding position when stopped

Monitoring operation (H02P 8/36 takes precedence)
References
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Protection against faults

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

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

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Ward-Leonard arrangements

Vector control

Feeding a network by two or more generators

For charging batteries

{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

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Emergency protective arrangements with automatic interruption of supply

{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:

Wind mills

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

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Control of generator circuit during starting or stopping of driving means

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

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

{controlling voltage (H02P 9/302 takes precedence)}
References
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Brushless excitation

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

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

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

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

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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)

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

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

Starter - generator

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

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

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

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Starting

Stopping

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

Vector control

Feeding a network in conjunction with a generator or another converter

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
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Regulation systems using transformers, reactors or choke coils

Transformers

Feeding a network in conjunction with a generator or a converter

Control or regulation of converters

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
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Vector control

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

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

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

The stator phase currents are measured and converted into a corresponding complex (space) vector. This current vector is then transformed to a coordinate system rotating with the rotor of the machine. Control of the machine is done in this in this rotating coordinate system. The calculated voltages in this in this rotating coordinate system are then transformed into real voltages which usually generated by an inverter bridge are then 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

specially adapted for very low speeds
References
Informative references

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

Determining the initial rotor position

Arrangements for starting

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

This place does not cover:

Starting

Stopping

Two or more motor

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

DC motors

{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:

A Synchronous Motor has an inherent instability 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.

References
Limiting references

This place does not cover:

Torque ripple from brushless commutation

For reluctance motors

Motor oscillations that are synchronous to the motor position

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

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

This place does not cover:

Starting

Stopping

Two or more motor

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

DC motors

Stepping motors

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

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

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

This place does not cover:

DC motors

{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

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

for pole-changing
Definition statement

This place covers:

Pole changing for starting an individual polyphase induction motor

Pole changing for starting an individual synchronous motor

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:

Starting

Stopping

Two or more motor

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

DC motors

Stepping motors

Special rules of classification

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

Doubly fed generators

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

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

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

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

Stopping

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

Vector control

Emergency protective circuit arrangements for electric machines involving automatic switching

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

{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:

Protection of the motor by measures taken in the motor controller.

Measures taken in the motor controller to assure the best possible operation of the motor under the given (faulty) circumstance.

e.g. protection against broken phase, against power failure, against power failure.

References
Limiting references

This place does not cover:

Protection during start

Protection for stepper motors

Generator overload and transient protection

Protection of inverter circuit

Informative references

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

Emergency protective arrangements with automatic interruption of supply

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

{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

{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