Patent US3755712A successfully refreshed from Google Patents.
US3755712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fault protection for dc motor thyristor power supplies
Assignee: Schneider Electric USA Inc
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Filing: 1972-09-07
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Granted: 1973-08-28
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Expires: 1992-09-07
Abstract
Abstract In a regenerative DC motor control, a line voltage failure during regeneration ordinarily results in a fault current of sufficient magnitude to damage any conducting thyristors or their protective fuses. To prevent such damage, a gate suppression circuit operates upon occurrence of a fault to prevent further firing of thyristors. A fault protection module controls the connection of a charged capacitor across the then-conducting thyristors at a predetermined time after the fault to permit resetting of those thyristors and prevent any damage to thyristors or fuses.
Inventors
- 👤 Viney T De
- 👤 R Brennan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:15
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/08; H02H7/0833
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
75 words
In a regenerative motor control system comprising a direct current motor, a source of alternating voltage, converter means connected to the source of alternating voltage for controlling energizatiOn of the motor, firing means for supplying firing pulses to said converter means, and means operative upon occurrence of a line failure for terminating said firing pulses, the improvement comprising protection means operative upon occurrence of a line failure for diverting current flow from said converter means.
Claim 2
Dependent Claim
75 words
In a regenerative motor control system comprising a direct current motor, a source of alternating voltage, converter means connected to the source of alternating voltage for controlling energizatiOn of the motor, firing means for supplying firing pulses to said converter means, and means operative upon occurrence of a line failure for terminating said firing pulses, the improvement comprising protection means operative upon occurrence of a line failure for diverting current flow from said converter means.
Claim 3
Dependent Claim
52 words
A regenerative motor control system as in claim 1 wherein said protection means comprises energy storage means for supporting a voltage thereacross, switching means having a conducting condition for discharging said storage means, and control means operative upon occurrence of a line failure to switch said switching means to its conducting condition.
Claim 4
Dependent Claim
42 words
A regenerative motor control system as in claim 2 wherein said switching means comprises a thyristor having a gate, said energy storage means comprises a capacitor, and said protection means includes means serially connecting said thyristor and said capacitor across said motor.
Claim 5
Dependent Claim
189 words
In a regenerative motor control system comprising a direct current motor having an armature, a source of alternating voltage, a first converter means connected to the source of alternating voltage for controlling energization of the motor in one direction of rotation of the armature, a second converter means connected to the source of alternating voltage for controlling energization of the motor in an other direction of rotation of the armature, firing means for supplying firing pulses selectively to each of said first and second converter means, and means operative upon occurrence of a line failure for terminating said firing pulses, the improvement comprising a first protection means operative upon occurrence of a line fai ure for diverting current flow from said first converter means, a second protection means operative upon occurrence of a line failure for diverting current flow from said second converter means, and control means for preventing operation of the first protection means during operation of the motor with the armature rotating in said other direction and preventing operation of the second protection means during operation of the motor with the armature rotating in said one direction.
Claim 6
Dependent Claim
189 words
In a regenerative motor control system comprising a direct current motor having an armature, a source of alternating voltage, a first converter means connected to the source of alternating voltage for controlling energization of the motor in one direction of rotation of the armature, a second converter means connected to the source of alternating voltage for controlling energization of the motor in an other direction of rotation of the armature, firing means for supplying firing pulses selectively to each of said first and second converter means, and means operative upon occurrence of a line failure for terminating said firing pulses, the improvement comprising a first protection means operative upon occurrence of a line fai ure for diverting current flow from said first converter means, a second protection means operative upon occurrence of a line failure for diverting current flow from said second converter means, and control means for preventing operation of the first protection means during operation of the motor with the armature rotating in said other direction and preventing operation of the second protection means during operation of the motor with the armature rotating in said one direction.
Claim 7
Dependent Claim
51 words
A regenerative motor control system as in claim 4 wherein said first protection means comprises a first energy storage means and a first switching means serially connected across said motor, and said second protection means comprises a second energy storage means and a second switching means serially connected across said motor.
Claim 8
Dependent Claim
80 words
A regenerative motor control system as in cliam 5 wherein said first converter means conducts current through said motor in a first direction, said second converter means conducts current through said motor in a second direction, said first switching means comprises a first undirectional controlled conduction means aligned to conduct through said motor in said first direction and said second switching means comprises a second undirectional controlled conduction means aligned to conduct current through said motor in said second direction.
Claim 9
Dependent Claim
80 words
A regenerative motor control system as in cliam 5 wherein said first converter means conducts current through said motor in a first direction, said second converter means conducts current through said motor in a second direction, said first switching means comprises a first undirectional controlled conduction means aligned to conduct through said motor in said first direction and said second switching means comprises a second undirectional controlled conduction means aligned to conduct current through said motor in said second direction.
Claim 10
Independent Claim
69 words
A method for protecting a regenerative motor control system, including a motor, converter means for controlling energization of the motor, and firing means for controlling operation of said converter means, from faults occurring due to a line failure, said method comprising the steps of charging a capacitor, causing said firing means to terminate operation of said converter means, and operating switching means to discharge the capacitor through the motor.
Claim 11
Independent Claim
69 words
A method for protecting a regenerative motor control system, including a motor, converter means for controlling energization of the motor, and firing means for controlling operation of said converter means, from faults occurring due to a line failure, said method comprising the steps of charging a capacitor, causing said firing means to terminate operation of said converter means, and operating switching means to discharge the capacitor through the motor.
References Cited (Backward Citations)
US3657625A
Cited
US3590323A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |