GB1558593A - Electric motor driven vehicles - Google Patents

Electric motor driven vehicles Download PDF

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Publication number
GB1558593A
GB1558593A GB48969/75A GB4896975A GB1558593A GB 1558593 A GB1558593 A GB 1558593A GB 48969/75 A GB48969/75 A GB 48969/75A GB 4896975 A GB4896975 A GB 4896975A GB 1558593 A GB1558593 A GB 1558593A
Authority
GB
United Kingdom
Prior art keywords
generator
output
relay
switch
contacts
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB48969/75A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cableform Ltd
Original Assignee
Cableform Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cableform Ltd filed Critical Cableform Ltd
Priority to GB48969/75A priority Critical patent/GB1558593A/en
Priority to IT28211/76A priority patent/IT1068880B/en
Priority to US05/736,605 priority patent/US4132934A/en
Priority to DE19762650187 priority patent/DE2650187A1/en
Priority to SE7613320A priority patent/SE7613320L/en
Priority to FR7635727A priority patent/FR2332880A1/en
Publication of GB1558593A publication Critical patent/GB1558593A/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
    • B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
    • B60L15/2009—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed for braking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L7/00—Electrodynamic brake systems for vehicles in general
    • B60L7/10—Dynamic electric regenerative braking
    • B60L7/12—Dynamic electric regenerative braking for vehicles propelled by dc motors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P7/00—Arrangements for regulating or controlling the speed or torque of electric DC motors
    • H02P7/06—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current
    • H02P7/18—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power
    • H02P7/24—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices
    • H02P7/28—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices
    • H02P7/285—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices controlling armature supply only
    • H02P7/29—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices controlling armature supply only using pulse modulation
    • H02P7/2913—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices controlling armature supply only using pulse modulation whereby the speed is regulated by measuring the motor speed and comparing it with a given physical value
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/64—Electric machine technologies in electromobility
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

Description

(54 IMPROVEMENTS IN OR RELATING TO ELECTRIC MOTOR DRIVEN VEHICLES (71) We, CABLEFORM LIMITED, a British Company of Green Lane, Romiley, Stockport, Cheshire, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to control arrangements for vehicles driven by electric motors.
Such motors are generally supplied with power from a battery via a D.C. switch which provides pulses of current. The frequency and/or mark-space ratio of the pulses is varied to vary the mean power supplied to the motor.
The variation of the mean power is under the control of the vehicle operator but with such vehicles as fork-lift trucks it is desirable to provide for dynamic braking of the truck in the event of the truck running away after having been left standing without adequate mechanical braking.
It is also desirable to limit the speed which can be attained on downhill gradients, particularly when the truck is heavily loaded.
British Patent Specification No. 1 381 856 describes a control arrangement for dynamically breaking a vehicle driven by an electric motor having a plurality of field windings.
In the described control arrangement a generator is mechanically coupled to the motor, and circuit closure means are arranged to complete a circuit between the output of the generator and one of the field windings when the motor is de-energised.
Unfortunately the described arrangement cannot be used with a motor having only one field winding. It is an object of the present invention to provide a control arrangement for dynamically braking a vehicle driven by an electric motor having a single field winding.
According to the invention, there is provided a control arrangement for a vehicle driven by an electric motor having a single field winding, comprising means for controlling the supply of power to the motor, a permanent magnet generator mechanically coupled to the motor, and circuit closure means arranged to complete a circuit between the output of the generator and the field winding to dynamically brake the motor when the motor is de-energised by the controlling means, said generator output constituting the sole and entire source of electrical energy supplied to said single field winding during dynamic braking.
When the motor is de-energised for example as a result of the vehicle being left stationary with its power supply switched off or disconnected, any tendency for the vehicle to run away on a slope due to failure to set the manual parking brake correctly may be inhibited by dynamic braking, the vehicle at most creeping away very slowly.
Preferably, means are provided for sensing the output of the generator and for completing a circuit between the output of the generator and the said motor field winding when the output reaches a predetermined value so that dynamic braking is applied to the motor.
An embodiment of the invention will now be described by way of example, with reference to the accompanying drawing, which is a schematic circuit diagram of a control arrangement in accordance with the invention.
The control arrangement shown in the accompanying drawing is installed in a forklift truck which is powered by a battery 1, the energy supplied to an electric drive motor 2, 3, of the truck being controlled by an C)N/OFF switch and circuit protection contacts 4 and a D.C. switch 5 which is pulse controlled to vary the mean power to the motor. The armature 2 of the motor is shunted by a diode 6 which allows circulation of armature current during dynamic braking. The single field winding 3 is in series with the armature 2 through the intermediary of a reversing switch 7. The reversing switch 7 is shown in its neutral position. The motor may be energised in the forward direction by moving one of the contacts of the switch 7 to its alternative position. and in the reversed direction by moving the other contact of the switch 7.
A permanent magnet generator 8 is mechanically coupled for rotation with the motor, the output of the generator being taken to a relay 9 which, when the output reaches a predetermined level corresponding to the desired speed limit, closes contacts 10 and also automatically causes the switch 7 to assume the condition illustrated, thereby stopping the flow of current to the motor from the battery 1. The contacts 10 of the relay 9 are included in a circuit comprising the generator 8, the field winding 3 of the motor, and a resistance 11.When the contacts 10 close, the generator output alone is fed to the field winding 3 and is so connected as to provide dynamic braking to a degree determined by the resistance 11 in the circuit The control of the switch 7 by the relay 9 may be achieved by the relay 9 closing further contacts (not shown) and thereby energising a circuit for resetting the switch 7.
Irrespective of the truck operator, if the truck exceeds a predetermined speed, for example, on a downhill gradient, the relay 9 will close the contacts 10 and reset the switch 7 and dynamic braking will be applied to restrict the speed, the relay falling out again at a preset lower speed which may be zero. The polarity of the generator output is dependent upon the direction of rotation and therefore braking is applied irrespective of the direction of movement of the track.
Additionally, across the resistance 11 and the relay contacts 10 there is provided a set of normally closed contacts 12 of a relay 13. The relay 13 is energised through the ON/OFF switch and circuit protection contacts shown diagrammatically at 4 when the truck is being operated so that the contacts 12 are open when the truck is in use. When the truck is left standing, either with the switch 4 turned to OFF or with its supply disconnected, the contacts 12 are closed so that the output of the generator 8 is connected directly to the field winding 3. If, for some reason such as defective mechani cal braking, the truck attempts to move away on a slope, the whole of the generator output is applied to the single field winding to give heavy dynamic braking, thereby preventing a run-away or at least reducing it to a low speed creep.As mentioned previously, his braking will be irrespective of direction of attempted travel of the truck.
Two diodes 14, 15 are provided to prevent shorting out of the field winding 3 and thus the output of the generator 8 as a result of the switch 7 being in the neutral position. If the switch 7 was replaced by a switch which did not short out the field winding 3 when in its neutral position, the diode 14, 15 would not be required.
To provide adequate dynamic braking, it is necessary for the output of the generator 8 to be matched to the characteristics of the winding 3. For most motors a high current low voltage generator output is required, for example 4 volts, 25 amps.
WHAT WE CLAIM IS: 1. A control arrangement for a vehicle driven by an electric motor having a single field winding, comprising means for controlling the supply of power to the motor, a permanent magnet generator mechanically coupled to the motor, and circuit closure means arranged to complete a circuit between the output of the generator and the field winding to dynamically brake the motor when the motor is de-energised by the controlling means, said generator output constituting the sole and entire source of electrical energy supplied to said single field winding during dynamic braking.
2. A control arrangement according to claim 1, comprising means for sensing the output of the generator and for completing a circuit between the output of the generator and the said motor field winding to apply dynamic braking when the sensed output reaches a predetermined value.
3. A control arrangement according to claim 2, comprising a relay connected across the generator, and contacts controlled by the relay closing to apply the output of the generator to the single field winding when the generator output reaches a predetermined level.
4. A control arrangement according to any preceding claim, comprising a relay arranged to be energised whenever the motor and power supply controlling means are connected to a power supply, which relay when de-energised closes contacts to apply the output of the generator to the single field winding.
5. A control arrangement substantially as hereinbefore described with reference to the accompanying drawing.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. shunted by a diode 6 which allows circulation of armature current during dynamic braking. The single field winding 3 is in series with the armature 2 through the intermediary of a reversing switch 7. The reversing switch 7 is shown in its neutral position. The motor may be energised in the forward direction by moving one of the contacts of the switch 7 to its alternative position. and in the reversed direction by moving the other contact of the switch 7. A permanent magnet generator 8 is mechanically coupled for rotation with the motor, the output of the generator being taken to a relay 9 which, when the output reaches a predetermined level corresponding to the desired speed limit, closes contacts 10 and also automatically causes the switch 7 to assume the condition illustrated, thereby stopping the flow of current to the motor from the battery 1. The contacts 10 of the relay 9 are included in a circuit comprising the generator 8, the field winding 3 of the motor, and a resistance 11.When the contacts 10 close, the generator output alone is fed to the field winding 3 and is so connected as to provide dynamic braking to a degree determined by the resistance 11 in the circuit The control of the switch 7 by the relay 9 may be achieved by the relay 9 closing further contacts (not shown) and thereby energising a circuit for resetting the switch 7. Irrespective of the truck operator, if the truck exceeds a predetermined speed, for example, on a downhill gradient, the relay 9 will close the contacts 10 and reset the switch 7 and dynamic braking will be applied to restrict the speed, the relay falling out again at a preset lower speed which may be zero. The polarity of the generator output is dependent upon the direction of rotation and therefore braking is applied irrespective of the direction of movement of the track. Additionally, across the resistance 11 and the relay contacts 10 there is provided a set of normally closed contacts 12 of a relay 13. The relay 13 is energised through the ON/OFF switch and circuit protection contacts shown diagrammatically at 4 when the truck is being operated so that the contacts 12 are open when the truck is in use. When the truck is left standing, either with the switch 4 turned to OFF or with its supply disconnected, the contacts 12 are closed so that the output of the generator 8 is connected directly to the field winding 3. If, for some reason such as defective mechani cal braking, the truck attempts to move away on a slope, the whole of the generator output is applied to the single field winding to give heavy dynamic braking, thereby preventing a run-away or at least reducing it to a low speed creep.As mentioned previously, his braking will be irrespective of direction of attempted travel of the truck. Two diodes 14, 15 are provided to prevent shorting out of the field winding 3 and thus the output of the generator 8 as a result of the switch 7 being in the neutral position. If the switch 7 was replaced by a switch which did not short out the field winding 3 when in its neutral position, the diode 14, 15 would not be required. To provide adequate dynamic braking, it is necessary for the output of the generator 8 to be matched to the characteristics of the winding 3. For most motors a high current low voltage generator output is required, for example 4 volts, 25 amps. WHAT WE CLAIM IS:
1. A control arrangement for a vehicle driven by an electric motor having a single field winding, comprising means for controlling the supply of power to the motor, a permanent magnet generator mechanically coupled to the motor, and circuit closure means arranged to complete a circuit between the output of the generator and the field winding to dynamically brake the motor when the motor is de-energised by the controlling means, said generator output constituting the sole and entire source of electrical energy supplied to said single field winding during dynamic braking.
2. A control arrangement according to claim 1, comprising means for sensing the output of the generator and for completing a circuit between the output of the generator and the said motor field winding to apply dynamic braking when the sensed output reaches a predetermined value.
3. A control arrangement according to claim 2, comprising a relay connected across the generator, and contacts controlled by the relay closing to apply the output of the generator to the single field winding when the generator output reaches a predetermined level.
4. A control arrangement according to any preceding claim, comprising a relay arranged to be energised whenever the motor and power supply controlling means are connected to a power supply, which relay when de-energised closes contacts to apply the output of the generator to the single field winding.
5. A control arrangement substantially as hereinbefore described with reference to the accompanying drawing.
GB48969/75A 1975-11-28 1975-11-28 Electric motor driven vehicles Expired GB1558593A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
GB48969/75A GB1558593A (en) 1975-11-28 1975-11-28 Electric motor driven vehicles
IT28211/76A IT1068880B (en) 1975-11-28 1976-10-12 IMPROVEMENTS IN OR RELATING TO VEHICLES COMMANDED BY AN ELECTRIC MOTOR
US05/736,605 US4132934A (en) 1975-11-28 1976-10-28 Electric motor driven vehicles
DE19762650187 DE2650187A1 (en) 1975-11-28 1976-10-29 CONTROL DEVICE FOR A VEHICLE WITH ELECTRIC MOTOR DRIVE
SE7613320A SE7613320L (en) 1975-11-28 1976-11-26 CONTROL ARRANGEMENT FOR A VEHICLE
FR7635727A FR2332880A1 (en) 1975-11-28 1976-11-26 ELECTRIC MOTOR VEHICLE CONTROL DEVICE

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB48969/75A GB1558593A (en) 1975-11-28 1975-11-28 Electric motor driven vehicles

Publications (1)

Publication Number Publication Date
GB1558593A true GB1558593A (en) 1980-01-09

Family

ID=10450641

Family Applications (1)

Application Number Title Priority Date Filing Date
GB48969/75A Expired GB1558593A (en) 1975-11-28 1975-11-28 Electric motor driven vehicles

Country Status (5)

Country Link
DE (1) DE2650187A1 (en)
FR (1) FR2332880A1 (en)
GB (1) GB1558593A (en)
IT (1) IT1068880B (en)
SE (1) SE7613320L (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2334496A (en) * 1998-02-20 1999-08-25 Rover Group Hybrid vehicle with controlled downhill electrodynamic braking

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3428898A1 (en) * 1984-08-04 1986-02-13 ETWO Elektrotechnische- und Transportgeräte Gerhard Greger, 8431 Niederhofen Electrical safety device for a stacker vehicle which can be moved guided by drawbar

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2334496A (en) * 1998-02-20 1999-08-25 Rover Group Hybrid vehicle with controlled downhill electrodynamic braking
GB2334496B (en) * 1998-02-20 2001-09-26 Rover Group A vehicle power train

Also Published As

Publication number Publication date
DE2650187A1 (en) 1977-06-08
FR2332880A1 (en) 1977-06-24
IT1068880B (en) 1985-03-21
SE7613320L (en) 1977-05-29

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee