US3930189A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wheel slip correction system
Assignee: General Electric Co
•
Filing: 1974-10-11
•
Granted: 1975-12-30
•
Expires: 1994-10-11
Abstract
Abstract A wheel slip control system for electric traction motor drives employing series-type direct current traction motors having field and armature windings connected in series electrical circuit relationship, a power rectifier and a source of alternating current supplying the power rectifier. The series-type traction motors are connected across the output from the power rectifier for the supply of normal excitation direct current. The improvement comprises a current transformer having primary and secondary windings wound on a common core. The primary winding is serially connected in the supply connection between the alternating current power source and the power rectifier. The secondary rectifier is provided with its output connected to supply auxiliary field current to the field winding of each series-type direct current traction motor in addition to the normal direct current excitation supplied through the power rectifier. The polarity of the auxiliary field current is such that upon addition to the normal excitation direct current, the field current is maintained substantially constant or slightly less so from what it had been prior to a wheel slippage condition, and a detector is provided for detecting a wheel slippage condition and controlling supply of the output current from the secondary winding of the current transformer to the secondary rectifier for enabling the supply of auxiliary field current to the field winding of the series-type direct current traction motor that was slipping.
Inventors
- 👤 Russell M Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:58
CPC Classifications
B; B60; B60L; B60L3/00; B60L3/10; B60L2200/00; B60L2200/26; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/64
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
201 words
A wheel slip control system for electric traction motors employing series-type direct current traction motors having field and armature windings connected in series electrical circuit relationship, power rectifier means and means for supplying alternating current to the power rectifier means, the series-type traction motors being connected across the output from the power rectifier means for the supply of normal excitation direct current thereto, the improvement comprising current transformer means having primary and secondary windings wound on a common core, the primary winding being serially connected in the supply connection between the means for supplying alternating current and the power rectifier means, secondary rectifier means having the output thereof upon excitation coupled to supply auxiliary field current to the field winding of each series-type direct current traction motor in addition to the normal direct current excitation from the power rectifier means, the polarity of the auxiliary field current being such that upon addition to the normal excitation direct current a reduction in the tractive effort of the motor results, and means responsive to the occurrence of a slippage condition for effectively supplying output current from the secondary winding of the current transformer means to the secondary rectifier means to excite the same.
Claim 2
Dependent Claim
201 words
A wheel slip control system for electric traction motors employing series-type direct current traction motors having field and armature windings connected in series electrical circuit relationship, power rectifier means and means for supplying alternating current to the power rectifier means, the series-type traction motors being connected across the output from the power rectifier means for the supply of normal excitation direct current thereto, the improvement comprising current transformer means having primary and secondary windings wound on a common core, the primary winding being serially connected in the supply connection between the means for supplying alternating current and the power rectifier means, secondary rectifier means having the output thereof upon excitation coupled to supply auxiliary field current to the field winding of each series-type direct current traction motor in addition to the normal direct current excitation from the power rectifier means, the polarity of the auxiliary field current being such that upon addition to the normal excitation direct current a reduction in the tractive effort of the motor results, and means responsive to the occurrence of a slippage condition for effectively supplying output current from the secondary winding of the current transformer means to the secondary rectifier means to excite the same.
Claim 3
Dependent Claim
49 words
A wheel slip control system according to claim 1 wherein the current transformer means has a current transformation ratio corresponding in number to the number of series connected direct current traction motor excitation circuit paths connected in parallel circuit relationship across the output of the main power rectifier means.
Claim 4
Dependent Claim
75 words
A wheel slip control system according to claim 2 wherein the auxiliary rectifier means is connected in series circuit relationship with the field winding of a respective series-type direct current traction motor, and the system further includes feedback diode means connected across the series connected field winding and series connected auxiliary rectifier means in reverse polarity relationship with respect to the auxiliary rectifier means for circulating auxiliary field current through the series connected field winding.
Claim 5
Dependent Claim
57 words
A wheel slip control system according to claim 3 wherein the auxiliary rectifier means comprises a rectifier bridge having one set of diagonally opposed terminals connected in series circuit relationship with the series connected field winding and the remaining set of diagonally opposed terminals connected across the output from the secondary winding of the current transformer means.
Claim 6
Dependent Claim
176 words
A wheel slip control system according to claim 4 wherein the system is designed for use with a multi-phase source of alternating current, the current transformer means is a multi-phase transformer means having a number of separate core paths corresponding in number to the number of phases of the alternating current source with each core path supporting a corresponding set of primary and secondary windings, the auxiliary rectifier bridge has a number of branches corresponding in number to the number of phases with each branch of the auxiliary rectifier bridge being separately connected to a corresponding secondary winding of the multi-phase current transformer means whereby each phase connection to the multi-phase alternating current source excites a different set of primary and secondary windings on the current transformer means, and there are a number of series connected excitation circuit paths containing series-type direct current traction motors connected in parallel across the output from the main power rectifier with the number of parallel circuit paths corresponding in number to the current transformation ratio of the current transformer means.
Claim 7
Dependent Claim
76 words
A wheel slip control system according to claim 5 wherein each branch of each auxiliary rectifier bridge includes a pair of series connected diode rectifiers with the output of each secondary winding of the multi-phase current transformer means having one terminal connected in common with a terminal of an adjacent secondary winding and the remaining terminal connected to the mid-tap point of the series connected diode rectifiers of an associated branch of the auxiliary rectifier bridge.
Claim 8
Dependent Claim
21 words
A wheel slip control system according to claim 6 wherein the multi-phase alternating current supply comprises a three-phase alternating current supply.
Claim 9
Dependent Claim
130 words
A wheel slip control system according to claim 1 wherein the secondary rectifier means comprises a secondary rectifier bridge and the output of the secondary winding is connected across the secondary rectifier bridge, and the system further includes short-circuiting silicon control rectifier means connected across the secondary rectifier bridge in parallel with the output from the secondary winding of the current transformer means, wheel slip detector means for sensing a wheel slip condition of the traction motor being controlled and deriving an output error control system, and means supplying the output from said wheel slip detector means to control conduction through said short-circuiting silicon control rectifier means whereby the short-circuiting silicon control rectifier means is maintained in a conducting and short-circuiting condition until the occurrence of a wheel slip condition.
Claim 10
Dependent Claim
79 words
A wheel slip control system according to claim 1 wherein the secondary rectifier means comprises a secondary rectifier bridge directly connected across the output of the secondary winding, and the system further includes auxiliary secondary winding means on each of the current transformer means, short-circuiting means connected across said auxiliary secondary winding means, and wheel slip detector means having the output thereof connected to and controlling said short-circuiting means in response to the occurrence of a wheel slippage condition.
Claim 11
Dependent Claim
71 words
A wheel Slip control system according to claim 9 wherein said short-circuiting means conprises short-circuiting silicon control rectifier means connected across the auxiliary secondary winding means and responsive to the output of the wheel slip detector means such that the short-circuiting silicon control rectifier means is maintained conducting in the absence of a wheel slip condition and upon occurrence of wheel slippage, is turned off by the wheel slip detector means.
Claim 12
Dependent Claim
97 words
A wheel slip control system according to claim 9 wherein the short-circuiting means comprises control transistor means connected in series circuit relationship with a separate source of direct current and with the series circuit thus comprised being connected across at least two auxiliary secondary windings of two separate current transformer means, the two auxiliary secondary windings being connected in current opposition whereby the control transistor means controls only the auxiliary direct current energy source excitation of the two auxiliary secondary windings and the output of the sheel slip detector means controls operation of the control transistor means.
References Cited (Backward Citations)
US3183422A
Cited
US3296510A
Cited
US3321684A
Cited
US3629676A
Cited
US3719868A
Cited
US3737745A
Cited
US3743900A
Cited
US3790871A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |