Patent DE2503784A1 successfully refreshed from Google Patents.
US3798522A
Expired / Lapsed
US
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Arrangement for exciting an asynchronous start synchronous motor
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1973-06-05
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Granted: 1974-03-19
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Expires: 1993-06-05
Abstract
Abstract An arrangement for exciting the rotating field winding of a synchronous motor includes an alternating current exciter whose armature is mounted on the motor shaft and delivers direct current to the field winding by means of a main rectifier bridge circuit also mounted on the motor shaft. The negative half of the rectifier bridge consists of controllable semiconductor elements and the positive half of non-controllable type semiconductor elements. The controllable semiconductor elements in the bridge perform in a normal manner during synchronous operation of the motor but means in the form of an auxiliary rectifier arrangement are provided to render them non-conductive during asynchronous starting thus to cut off current flow from the output of the main rectifier bridge to the field winding of the motor.
Inventors
- 👤 H Pisecker
- 👤 W Schicht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:34
CPC Classifications
H; H02; H02P; H02P1/00; H02P1/16; H02P1/46; H02P1/50
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
263 words
In an arrangement for exciting an asynchronous-start synchronous motor, wherein the rotating winding of an alternating current exciter armature mounted on the shaft of the synchronous motor is connected, without sliprings, by way of a co-rotating rectifier bridge connection to the rotating field winding provided in the synchronous motor and having at least one parallel resistor, and wherein controlled converter valves are provided for the temporary separation of the rectifier bridge connection from the field winding during asynchronous operation, the rectifier valves provided in one half of the bridge connection being uncontrolled and those of the other half of the bridge being controlled and a control device, which consists of another diode auxiliary rectifier arrangement together with a loading resistor, being connected to the armature winding of the exciter, the improvement wherein the controlled converter valves of the rectifier bridge connection are located in the negative half of the multi-phase bridge, each phase of the exciter armature winding being connected respectively direct to the cathode of respective converter valves of the rectifier bridge and to the anode of respective diodes of the half of the auxiliary rectifier arrangement which is not connected to the control electrodes of the converter valves, the cathodes of said diodes being conjointly connected to one terminal of the auxiliary resistor and the second terminal of this resistor being connected to the interconnection point of the anodes of the diodes which belong to the other half of the auxiliary rectifier arrangement and the cathodes of which are respectively connected to the control electrodes of the appertaining controlled converter valves.
Claim 2
Dependent Claim
263 words
In an arrangement for exciting an asynchronous-start synchronous motor, wherein the rotating winding of an alternating current exciter armature mounted on the shaft of the synchronous motor is connected, without sliprings, by way of a co-rotating rectifier bridge connection to the rotating field winding provided in the synchronous motor and having at least one parallel resistor, and wherein controlled converter valves are provided for the temporary separation of the rectifier bridge connection from the field winding during asynchronous operation, the rectifier valves provided in one half of the bridge connection being uncontrolled and those of the other half of the bridge being controlled and a control device, which consists of another diode auxiliary rectifier arrangement together with a loading resistor, being connected to the armature winding of the exciter, the improvement wherein the controlled converter valves of the rectifier bridge connection are located in the negative half of the multi-phase bridge, each phase of the exciter armature winding being connected respectively direct to the cathode of respective converter valves of the rectifier bridge and to the anode of respective diodes of the half of the auxiliary rectifier arrangement which is not connected to the control electrodes of the converter valves, the cathodes of said diodes being conjointly connected to one terminal of the auxiliary resistor and the second terminal of this resistor being connected to the interconnection point of the anodes of the diodes which belong to the other half of the auxiliary rectifier arrangement and the cathodes of which are respectively connected to the control electrodes of the appertaining controlled converter valves.
Claim 3
Dependent Claim
83 words
An arrangement according to claim 1, wherein the interconnected cathodes of the uncontrolled rectifier valves of the positive half of the rectifier bridge connection are connected both to the field winding and to the auxiliary resistor whereby in addiTion to their function in the rectifier bridge connection said uncontrolled rectifier valves also perform the function of the diodes which are disposed in the auxiliary rectifier arrangement and which are connected on the anode side to the individual phases of the exciter armature winding.
Claim 4
Dependent Claim
41 words
An arrangement according to claim 1 wherein the auxiliary rectifier valves supplying the control current to the controlled converter valves of the rectifier bridge arrangement are in the form of semiconductor thyratrons which ignite-through only when a threshold voltage is exceeded.
Claim 5
Dependent Claim
19 words
An arrangement according to claim 3, wherein the semiconductor thyratrons are in the form of Zener voltage controlled thyristors.
Claim 6
Dependent Claim
225 words
An arrangement according to claim 1, wherein the interconnected cathodes of the uncontrolled rectifiers of the positive half of the rectifier bridge are connected via a resistor to the interconnected cathodes of the diodes of the positive half of the auxiliary rectifier arrangement, and wherein between the interconnected anodes of the diodes of the negative half of the auxiliary rectifier and the terminal, facing these diodes, of the auxiliary resistor a series-parallel network is connected which contains the following elements: a. a first forward-connected thyristor in series between the auxiliary resistor and the diodes of the negative half of the auxiliary rectifier; b. a branch parallel to the anode-cathode section of said first thyristor and consisting of the series connection of a second, likewise forward-biased thyristor, a resistor, and a first diode biased in the blocking direction, c. a first Zener diode lying between the point of connection of said resistor to said first diode and the control electrode of said first thyristor; d. a second Zener diode between the anode and the control electrode of said second thyristor; and that during synchronization the excitation of the exciter is so selected that the exciter voltage is higher than the Zener voltage of said first Zener diode and lower than the sum of the Zener voltages of said first Zener diode and said second Zener diode.
Claim 7
Dependent Claim
33 words
An arrangement according to claim 5, wherein between the point of connection of said resistor to said first diode and the negative pole of the rectifier bridge a second forward-biased diode is provided.
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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |