Patent US4801855A successfully refreshed from Google Patents.
US4801855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for controlling chopper
Assignee: Hitachi Ltd
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Filing: 1987-06-18
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Granted: 1989-01-31
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Expires: 2007-06-18
Abstract
Abstract The magnitude of current change for the change of input voltage or for the change of speed of rotation of the shunt motor is utilized, i.e., the shunt characteristics are utilized, and the voltage applied to the motor is limited so that the armature current decreases by an amount that corresponds to the increase in the armature voltage when slipping and to the decrease in the armature voltage when sliding have taken place, thereby to obtain improved adhesion characteristics. For this purpose according to the invention, an electromotive force of the motor is calculated from a motor speed detected by a detector and from a field current of the motor, a voltage drop caused by the motor resistance and the motor current is calculated, a motor voltage is calculated by adding the thus calculated voltage drop to the electromotive force of the motor, and the voltage applied to the motor is limited depending upon the calculated motor voltage.
Inventors
- 👤 Makoto Nohmi
- 👤 Eiji Kozu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:12
CPC Classifications
B; B60; B60L; B60L3/00; B60L3/10; B60L3/106; B60L2200/00; B60L2200/26; B60L2220/00; B60L2220/10; B60L2220/20; B60L2220/30; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/72; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/902; Y10S388/903; Y10S388/907; Y10S388/917; Y10S388/92; Y10S388/923; Y10S388/93
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
104 words
A method for controlling a chopper comprising: a step for calculating a first motor voltage to regulate motor current; a step for calculating a motor electromotive force from a motor speed detected by means which detects the motor speed and from a field current of the motor; a step for calculating a voltage drop caused by the motor resistance and motor current; a step for calculating a second motor voltage by adding said calculated voltage drop to said calculated motor electromotive force; and a step for limiting said first motor voltage within a value determined on the basis of said calculated second motor voltage.
Claim 2
Independent Claim
104 words
A method for controlling a chopper comprising: a step for calculating a first motor voltage to regulate motor current; a step for calculating a motor electromotive force from a motor speed detected by means which detects the motor speed and from a field current of the motor; a step for calculating a voltage drop caused by the motor resistance and motor current; a step for calculating a second motor voltage by adding said calculated voltage drop to said calculated motor electromotive force; and a step for limiting said first motor voltage within a value determined on the basis of said calculated second motor voltage.
Claim 3
Dependent Claim
46 words
A method of controlling a chopper according to claim 1, wherein said motor is the one that drives a vehicle that is to be driven by said motor, and said means which detects said motor speed is the one that detects the speed of said vehicle.
Claim 4
Dependent Claim
31 words
A method of controlling a chopper according to claim 1, wherein said motor resistance is an armature resistance, and said motor current is the one that corresponds to the armature current.
Claim 5
Dependent Claim
23 words
A method of controlling a chopper according to claim 3, wherein the current that corresponds to the armature current is a command current.
Claim 6
Dependent Claim
20 words
A method of controlling a chopper according to claim 2, wherein the vehicle speed, is detected from an unforced axle.
Claim 7
Dependent Claim
51 words
A method of controlling a chopper according to claim 2, wherein during the powering a minimum vehicle speed is selected out of vehicle speeds detected from a plurality of axles, and during the braking a maximum vehicle speed is selected out of the vehicle speeds detected from the plurality of axles.
Claim 8
Dependent Claim
56 words
A method of controlling a chopper according to claim 2, wherein the step for limiting applies the first motor voltage that is increased or decreased by an error between the diameter of a wheel of the drive axle to be controlled and the diameter of a wheel of the axle from which the speed is detected.
Claim 9
Independent Claim
101 words
A system for controlling a chopper comprising: means for providing a first motor voltage to regulate motor current; means for detecting a motor speed; means for calculating a motor electromotive force from a motor speed detected by said means and from a field current of the motor; means for calculating a voltage drop caused by the motor resistance and motor current; means for calculating a second motor voltage by adding said calculated voltage drop to said calculated motor electromotive force; and means for limiting said first motor voltage within a value determined on the basis of said calculated second motor voltage.
Claim 10
Independent Claim
101 words
A system for controlling a chopper comprising: means for providing a first motor voltage to regulate motor current; means for detecting a motor speed; means for calculating a motor electromotive force from a motor speed detected by said means and from a field current of the motor; means for calculating a voltage drop caused by the motor resistance and motor current; means for calculating a second motor voltage by adding said calculated voltage drop to said calculated motor electromotive force; and means for limiting said first motor voltage within a value determined on the basis of said calculated second motor voltage.
Claim 11
Dependent Claim
46 words
A system for controlling a chopper according to claim 8, wherein said motor is the one that drives a vehicle that is to be driven by said motor, and said means which detects said motor speed is the one that detects the speed of said vehicle.
Claim 12
Dependent Claim
19 words
A system for controlling a chopper according to claim 9, wherein the speed is detected from an unforced axle.
Claim 13
Dependent Claim
62 words
A system for controlling a chopper according to claim 9, wherein during the powering, said means for detecting the vehicle speed selects a minimum vehicle speed out of vehicle speeds detected from a plurality of axles and during the braking, said means for detecting the vehicle speed selects a maximum vehicle speed out of vehicle speeds detected from the plurality of axles.
Claim 14
Dependent Claim
58 words
A system for controlling a chopper according to claim 9, wherein the means for limiting the applied voltage applies the motor voltage that is increased or decreased by an error between the diameter of a wheel of the drive axle to be controlled and the diameter of a wheel of the axle from which the speed is detected.
Claim 15
Dependent Claim
66 words
A method of controlling a chopper according to claim 1, wherein said step for limiting said first motor voltage comprises: a step for calculating a compensation voltage on the basis of the motor voltage drop; a step for calculating a limit voltage by adding said compensation voltage to said calculated second motor voltage; a step for limiting said first motor voltage within said calculated limit voltage.
Claim 16
Dependent Claim
50 words
A method of controlling a chopper according to claim 13, wherein, said step for calculating a compensation voltage comprises: a step for obtaining a difference voltage between said limit voltage and said first motor voltage; and a step for calculating said compensation voltage on the basis of said difference voltage.
Claim 17
Dependent Claim
35 words
A method of controlling a chopper according to claim 13, wherein said compensation voltage has a limit value when said difference voltage is high and has a low value when said difference voltage is low.
Claim 18
Dependent Claim
24 words
A method of controlling a chopper according to claim 13, wherein said compensation voltage has a sufficiently long time constant for adhering to slipping.
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) | 1992-01-31 | 1992-08-01 | 1993-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-31 | 1996-08-01 | 1997-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-31 | 2000-08-01 | 2001-01-31 | $7700.00 | Window Closed / Lapsed |