US3569811A
Expired / Lapsed
US
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Dynamic braking system
Assignee: Westinghouse Electric Corp
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Filing: 1969-04-24
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Granted: 1971-03-09
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Expires: 1989-04-24
Abstract
Abstract There is disclosed an arrangement for controlling dynamic braking of a vehicle traction motor system wherein the effective average dynamic braking resistance is adjustable between predetermined minimum and maximum values, and wherein the motor field system is operated in full field mode or partial field mode, depending on whether commanded (requested) braking current at a given speed is greater or less than a predetermined value which for the given speed is at least that which would obtain in the full field mode and with the maximum effective average dynamic braking resistance in the circuit.
Inventors
- 👤 Lalan G Miller
- 👤 John M Mills
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:06
CPC Classifications
B; B60; B60L; B60L7/00; B60L7/003; B60L7/02; B60L7/04; H; H02; H02P; H02P3/00; H02P3/06; H02P3/18; H02P3/22; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/64
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
271 words
In a dynamic braking system for a motor circuit including motor means and dynamic braking means connected thereacross and which braking means is adjustable to vary its effective resistance between predetermined minimum and maximum values whereby the braking motor current may be varied between predetermined maximum and minimum values for any given motor speed, and wherein there is selecting means for commanding a value of motor current corresponding to a desired braking effort, said braking means being adjustable in response to said selection means: a. motor field means operable in respective high and low modes and providing greater field strength in the high mode than in the low mode for a given current; b. first signal providing means for providing a first signal that is a function of the braking current command; c. second signal providing means for providing a second signal that is a function of motor speed; and d. control means for controlling the status of said field means, said control means comprising means for comparing said first and second signals and providing certain conditions in response to predetermined relations between said signals, and means responsive to said certain conditions for 1. causing said field means to assume its low mode when, at any given speed within a predetermined speed range, the braking current command is less than a predetermined current value that increases as a function of speed increase, and 2. causing said field means to assume its high mode when, at any given speed within said speed range, the braking current command is greater than a certain current value that increases as a function of speed increase.
Claim 2
Dependent Claim
271 words
In a dynamic braking system for a motor circuit including motor means and dynamic braking means connected thereacross and which braking means is adjustable to vary its effective resistance between predetermined minimum and maximum values whereby the braking motor current may be varied between predetermined maximum and minimum values for any given motor speed, and wherein there is selecting means for commanding a value of motor current corresponding to a desired braking effort, said braking means being adjustable in response to said selection means: a. motor field means operable in respective high and low modes and providing greater field strength in the high mode than in the low mode for a given current; b. first signal providing means for providing a first signal that is a function of the braking current command; c. second signal providing means for providing a second signal that is a function of motor speed; and d. control means for controlling the status of said field means, said control means comprising means for comparing said first and second signals and providing certain conditions in response to predetermined relations between said signals, and means responsive to said certain conditions for 1. causing said field means to assume its low mode when, at any given speed within a predetermined speed range, the braking current command is less than a predetermined current value that increases as a function of speed increase, and 2. causing said field means to assume its high mode when, at any given speed within said speed range, the braking current command is greater than a certain current value that increases as a function of speed increase.
Claim 3
Dependent Claim
37 words
causing said field means to assume its high mode when, at any given speed within said speed range, the braking current command is greater than a certain current value that increases as a function of speed increase.
Claim 4
Dependent Claim
37 words
causing said field means to assume its high mode when, at any given speed within said speed range, the braking current command is greater than a certain current value that increases as a function of speed increase.
Claim 5
Dependent Claim
32 words
The combination as in claim 1 wherein said control means includes means for inhibiting operation of said field means in its low mode when the motor speed is below a predetermined value.
Claim 6
Dependent Claim
36 words
The combination as in claim 1 wherein said motor circuit is a traction motor circuit in a vehicle, and said motor means includes at least one traction motor coupled to a drivinG axle of the vehicle.
Claim 7
Dependent Claim
36 words
The combination as in claim 2 wherein said motor circuit is a traction motor circuit in a vehicle, and said motor means includes at least one traction motor coupled to a driving axle of the vehicle.
Claim 8
Dependent Claim
28 words
The combination as in claim 1 wherein said dynamic braking means comprises resistor means and a controllable chopper connected across at least a portion of said resistor means.
Claim 9
Dependent Claim
181 words
The combination as in claim 1 wherein said field means includes a field winding and a shunt, and wherein said control means comprises: a. First switching means which assumes a first state when the motor speed is above a predetermined speed, and a second state when the motor speed is below said predetermined speed; b. Second switching means which assumes a first state when at any given speed above said predetermined speed the braking current command is less than said predetermined current value, and a second state when at any given speed above said predetermined speed the braking current command is greater than said certain current value; and c. shunt control means which in a first state connects said shunt across said field winding and in a second state unshunts said field, said shunt control means assuming its first state in response to both said first and second switching means being in their first states, said shunt control means assuming its second state in response to at least one of said first and second switching means being in its second state.
Claim 10
Dependent Claim
32 words
The combination of claim 6 wherein said motor circuit is part of a vehicle traction system, and said motor means includes at least one motor coupled to an axle of the vehicle.
Claim 11
Independent Claim
240 words
The method of controlling a motor system in the dynamic braking mode, which system includes a motor and dynamic braking means connected thereacross and which braking means is adjustable to vary its effective resistance between minimum and maximum values whereby the braking current may be varied between predetermined maximum and minimum values for any given motor speed, and wherein there is selecting means for requesting a value of braking current corresponding to a desired braking effort, said braking means being adjustable in response to said selection means, and wherein said motor has a field winding, said method comprising the steps of utilizing respective signals that are a function of speed and a function of requested value of braking current to operate motor field in partial field mode when at any given motor speed the requested value of braking current is less than a predetermined current value that is not less than the braking current obtainable at the given speed with the motor in full field mode and the average effective resistance of said braking means at said predetermined maximum resistance value, and to operate the motor field in full field mode when at any given speed, the requested value of braking current is greater than a certain current value that is not less than the braking current obtainable at that speed with the motor in full field mode and the average effective braking resistance at said predetermined maximum resistance value.
Claim 12
Independent Claim
240 words
The method of controlling a motor system in the dynamic braking mode, which system includes a motor and dynamic braking means connected thereacross and which braking means is adjustable to vary its effective resistance between minimum and maximum values whereby the braking current may be varied between predetermined maximum and minimum values for any given motor speed, and wherein there is selecting means for requesting a value of braking current corresponding to a desired braking effort, said braking means being adjustable in response to said selection means, and wherein said motor has a field winding, said method comprising the steps of utilizing respective signals that are a function of speed and a function of requested value of braking current to operate motor field in partial field mode when at any given motor speed the requested value of braking current is less than a predetermined current value that is not less than the braking current obtainable at the given speed with the motor in full field mode and the average effective resistance of said braking means at said predetermined maximum resistance value, and to operate the motor field in full field mode when at any given speed, the requested value of braking current is greater than a certain current value that is not less than the braking current obtainable at that speed with the motor in full field mode and the average effective braking resistance at said predetermined maximum resistance value.
Claim 13
Dependent Claim
28 words
The combination as in claim 6 wherein said dynamic braking means comprises resistor means and a controllable chopper connected across at least a portion of said resistor means.
Claim 14
Dependent Claim
36 words
The combination as in claim 9 wherein said motor circuit is a traction motor circuit in a vehicle, and said motor means includes at least one traction motor coupled to a driving axle of the vehicle.
Claim 15
Dependent Claim
160 words
The combination as in claim 1 wherein said control means comprises: a. First switching means which assumes a first state when the speed of said motor means is above a predetermined speed, and a second state when the speed of the motor means is below said predetermined speed; b. Second switching means which assumes a first state when at any given speed above said predetermined speed the command current is less than said predetermined current value, and a second statE when at any given speed above said predetermined speed the commanded current is greater than said certain current value; and c. mode control means for (a) causing said field means to assume its low mode in response to both said first and second switching means being in their first states, and (b) causing said field means to assume it is high mode in response to at least one of said first and second switching means being in its second state.
Claim 16
Dependent Claim
36 words
The combination as in claim 11 wherein said motor circuit is a traction motor circuit in a vehicle, and said motor means includes at least one traction motor coupled to a driving axle of the vehicle.
Claim 17
Dependent Claim
28 words
The combination as in claim 11 wherein said dynamic braking means comprises resistor means and a controllable chopper connected across at least a portion of said resistor means.
Claim 18
Dependent Claim
36 words
The combination as in claim 13 wherein said motor circuit is a traction motor circuit in a vehicle, and said motor means includes at least one traction motor coupled to a driving axle of the vehicle.
Claim 19
Dependent Claim
36 words
The combination as in claim 5 wherein said motor circuit is a traction motor circuit in a vehicle, and said motor means includes at least one traction motor coupled to a driving axle of the vehicle.
Claim 20
Dependent Claim
31 words
The method of claim 8 wherein said predetermined current value increases as a function of motor speed increase, and said certain current value increases as a function of motor speed increase.
Claim 21
Dependent Claim
18 words
The combination of claim 6 wherein each of said first and second switching means comprises a summing amplifier.
Claim 22
Dependent Claim
18 words
The combination of claim 11 wherein each of said first and second switching means comprises a summing amplifier.
Claim 23
Dependent Claim
93 words
The combination as in claim 1 wherein said predetermined current value of clause D1 is not less than the value of braking current obtainable at the given speed of clause D1 and in high field mode when the average effective making resistance is at said predetermined maximum resistance value, and wherein said certain current value of clause D2 is not less than the value of braking current obtainable at the given speed of clause D2 and in high field mode when the average effective braking resistance is at said predetermined maximum resistance value.
Claim 24
Independent Claim
198 words
The method of controlling a motor system in the dynamic braking mode, which system includes a motor and dynamic braking means connected thereacross and which braking means is adjustable to vary its effective resistance between minimum and maximum values whereby the braking current may be varied between predetermined maximum and minimum values for any given motor speed, and wherein is selecting means for requesting a value of braking current corresponding to a desired braking effort, said braking means being adjustable being adjustable in response to said selection means, and wherein said motor has a field winding, said method comprising the steps of utilizing respective signals that are a function of speed and a function of requested value of braking current to operate motor field in partial field mode when at any given motor speed within a predetermined speed range the requested value of braking current is less than a predetermined value that increases as a function of speed increase, and to operate the motor field in full field mode when at any given speed within said speed range, the requested value of braking current is greater than a certain value that increases as a function of speed increase.
Claim 25
Independent Claim
198 words
The method of controlling a motor system in the dynamic braking mode, which system includes a motor and dynamic braking means connected thereacross and which braking means is adjustable to vary its effective resistance between minimum and maximum values whereby the braking current may be varied between predetermined maximum and minimum values for any given motor speed, and wherein is selecting means for requesting a value of braking current corresponding to a desired braking effort, said braking means being adjustable being adjustable in response to said selection means, and wherein said motor has a field winding, said method comprising the steps of utilizing respective signals that are a function of speed and a function of requested value of braking current to operate motor field in partial field mode when at any given motor speed within a predetermined speed range the requested value of braking current is less than a predetermined value that increases as a function of speed increase, and to operate the motor field in full field mode when at any given speed within said speed range, the requested value of braking current is greater than a certain value that increases as a function of speed increase.
References Cited (Backward Citations)
US2447666A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |