US3845368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric vehicle having programmed field control of separately excited dc drive motors
Assignee: Westinghouse Electric Corp
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Filing: 1973-03-30
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Granted: 1974-10-29
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Expires: 1993-03-30
Abstract
Abstract An electronic control system for controlling the torque speed characteristics and the regenerative braking of a separately excited DC drive motor in an electric vehicle drive system is provided. The input to the control system is a throttle setting. The control system includes electronic circuits which proportion the field excitation voltage applied to the DC drive motor to a given control function of the armature current and the throttle setting. In a modification, a voltage proportional to the DC drive motor speed can be fed to the controller so that the field voltage applied to the DC drive motor is a function of armature current, throttle setting, and the speed of the drive motor. A protective relay having its operating coil in series with the field winding and controlling a set of contacts in series with the armature of the DC drive motor is also provided to disconnect the drive motor if the field current drops below a predetermined value.
Inventors
- 👤 R Elco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:54
CPC Classifications
B; B60; B60L; B60L50/00; B60L50/50; B60L50/52; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/64; Y02T10/70; Y02T10/72; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/903; Y10S388/923; Y10S388/93
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
121 words
An electric vehicle comprising: a throttle means positionable between an off position and an open position; a direct current drive motor for moving the electric vehicle having, a separately excited field for controlling operation of said direct current drive motor and, an armature winding; a field controller means for supplying an excitation voltage to the separately excited field of said direct current drive motor which is a function of the setting of said throttle and the current flowing through the armature winding of said direct current drive motor; safety means for limiting the speed of said direct current drive motor; and, said safety means comprises a minimum voltage supply provided to the separately excited field of said direct current drive motor.
Claim 2
Dependent Claim
121 words
An electric vehicle comprising: a throttle means positionable between an off position and an open position; a direct current drive motor for moving the electric vehicle having, a separately excited field for controlling operation of said direct current drive motor and, an armature winding; a field controller means for supplying an excitation voltage to the separately excited field of said direct current drive motor which is a function of the setting of said throttle and the current flowing through the armature winding of said direct current drive motor; safety means for limiting the speed of said direct current drive motor; and, said safety means comprises a minimum voltage supply provided to the separately excited field of said direct current drive motor.
Claim 3
Dependent Claim
57 words
An electric vehicle as claimed in claim 1, wherein: said field controller supplies a voltage to the separately excited field of said direct current drive motor which is a function of the setting of said throttle, the current flowing through the armature of said direct current drive motor and the speed of said direct current drive motor.
Claim 4
Dependent Claim
55 words
An electric vehicle as claimed in claim 1, wherein: said field controller supplies a voltage to the separately excited field of said direct current drive motor which is a function of the setting of said throttle, the current flowing through the armature of said direct current drive motor and the speed of said electric vehicle.
Claim 5
Dependent Claim
90 words
An electric vehicle as claimed in claim 1, wherein: said field controller means supplies an excitation voltage (Vf) to the separately excited field of said direct current drive motor which is equal to Vf (V0 K1ia) (1-S) + K2iaS + V1 wherein V0 and V1 represent reference voltage settings, K1 and K2 represent potentiometer settings, S represents the position of said throttle means and is variable between an off position where S 0 and an open position where S 1 and ia represents the current flowing in the armature winding.
Claim 6
Dependent Claim
131 words
An electric vehicle as claimed in claim 2, wherein: said field controller means suPplies an excitation voltage (Vf) to the separately excited field of said direct current drive motor which is equal to Vf (V0 + K1ia Alpha K3n) (1-S) + K2iaS + V1 where V0 and V1 represent reference voltage settings, K1, K2 and K3 represent variable potentiometer settings, S represents the position of said throttle means which is variable between between an off position where S 0 and a full open position where S 1, ia represents the armature current flowing, Alpha is equal to one when ia is greater than 0 and Alpha is equal to zero when ia is less than 0, and n is a voltage proportional to the speed of said direct current drive motor.
Claim 7
Dependent Claim
118 words
An electric vehicle as claimed in claim 3, wherein said field controller means supplies a voltage to the separately excited field of said direct current drive motor which is equal to Vf (V0 + K1ia + Alpha K3n) (1-S) + K2iaS + V1 where V0 and V1 represent reference voltage settings, K1, K2 and K3 represent variable potentiometer settings, S represents the setting of said throttle means which is variable between an off position where S 0 and a full open position where S 1, ia represents the armature current flowing, Alpha has a value between zero and one determined by the armature current flowing and n is a voltage proportional to the speed of said electric vehicle.
Claim 8
Dependent Claim
55 words
An electric vehicle as claimed in claim 1, wherein: said direct current drive motor provides an output torque which is proportional to the setting of said throttle means; and regenerative braking means for providing a controlled regenerative braking torque which is substantially constant over a predetermined speed range for a given setting of said throttle.
Claim 9
Dependent Claim
142 words
An electric vehicle comprising: a throttle means; a direct current drive motor for moving the electric vehicle comprising, a separately excited field for controlling operation of said direct current drive motor and, an armature winding; field controller means for supplying an excitation voltage to the separately excited field of said direct current drive motor which is a function of the setting of said throttle and the current flowing through the armature winding of said direct current drive motor; safety means for limiting the speed of said direct current drive motor; said safety means comprising a minimum voltage supply to the separately excited field of said direct current drive motor; and disconnect means for opening the armature of said direct current drive motor when the current flowing through the separately excited field of said direct current drive motor falls below a predetermined value.
Claim 10
Dependent Claim
142 words
An electric vehicle comprising: a throttle means; a direct current drive motor for moving the electric vehicle comprising, a separately excited field for controlling operation of said direct current drive motor and, an armature winding; field controller means for supplying an excitation voltage to the separately excited field of said direct current drive motor which is a function of the setting of said throttle and the current flowing through the armature winding of said direct current drive motor; safety means for limiting the speed of said direct current drive motor; said safety means comprising a minimum voltage supply to the separately excited field of said direct current drive motor; and disconnect means for opening the armature of said direct current drive motor when the current flowing through the separately excited field of said direct current drive motor falls below a predetermined value.
Claim 11
Dependent Claim
70 words
An electric vehicle as claimed in claim 8, wherein said disconnect means comprises an operating coil connected in series with said separately excited sealed and a set of normally open contacts connected in series with the armature of said direct current drive motor and responsive to the field current flowing through said operating coil to open when the current flowing through said operating coil falls below a predetermined minimum value.
Claim 12
Dependent Claim
41 words
An electric vehicle as claimed in claim 8, wherein said field controller means comprises a shunt connected in series with the armature of said direct current drive motor to provide a voltage signal proportional to the current flowing through the armature.
Claim 13
Dependent Claim
39 words
An electric vehicle as claimed in claim 8, including a tachometer mechanically linked to said direct current drive motor to provide a voltage signal to said field controller means proportional to the speed of said direct current drive motor.
Claim 14
Dependent Claim
54 words
An electric vehicle as claimed in claim 3, includIng: drive wheel means being powered by said direct current drive motor for moving said electric vehicle; and, a tachometer means mechanically linked to said drive wheel means to provide a voltage signal to said field controller means proportional to the speed of said electric vehicle.
Claim 15
Dependent Claim
97 words
An electric vehicle comprising: a direct current drive motor for providing power to move said electric vehicle and being operable as a generator to provide regenerative braking when decelerating said electric vehicle; regenerative braking control means for controlling the operation of said direct current drive motor so as to provide a regenerative braking torque which is relatively constant over a wide speed range of said electric vehicle; and, minimum field excitation means connected to supply the field of said direct current drive with a minimum field excitation to limit the speed of said direct current drive motor.
Claim 16
Dependent Claim
97 words
An electric vehicle comprising: a direct current drive motor for providing power to move said electric vehicle and being operable as a generator to provide regenerative braking when decelerating said electric vehicle; regenerative braking control means for controlling the operation of said direct current drive motor so as to provide a regenerative braking torque which is relatively constant over a wide speed range of said electric vehicle; and, minimum field excitation means connected to supply the field of said direct current drive with a minimum field excitation to limit the speed of said direct current drive motor.
Claim 17
Dependent Claim
85 words
An electric vehicle as claimed in claim 13 wherein: a separately excited field is provided on said direct current drive motor for controlling the operation of said direct current drive motor; and said regenerative braking control means comprises, field excitation means electrically connected to said separately excited field so as to provide an excitation voltage to said separately excited electric field whereby the regenerative braking torque provided by said direct current drive motor is substantially constant over a predetermined speed range of said electric vehicle.
Claim 18
Dependent Claim
125 words
A battery powered electric vehicle comprising: a direct current drive motor for driving said electric vehicle having a separately excited field for controlling operation of said direct current drive motor and having an armature connectable to the battery; a field control means for supplying an excitation voltage to the separately excited field of said direct current drive motor so as to provide for a constant speed of said electric vehicle while the required output torque of said direct current drive motor is free to vary within a predetermined range; and, disconnect means for disconnecting the armature of the direct current drive motor from the battery when the current flowing through the separately excited field of said direct current drive motor falls below a predetermined value.
Claim 19
Dependent Claim
125 words
A battery powered electric vehicle comprising: a direct current drive motor for driving said electric vehicle having a separately excited field for controlling operation of said direct current drive motor and having an armature connectable to the battery; a field control means for supplying an excitation voltage to the separately excited field of said direct current drive motor so as to provide for a constant speed of said electric vehicle while the required output torque of said direct current drive motor is free to vary within a predetermined range; and, disconnect means for disconnecting the armature of the direct current drive motor from the battery when the current flowing through the separately excited field of said direct current drive motor falls below a predetermined value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |