Method and apparatus for the optimization of thyristor power supply transport time delay
First Claim
1. An arrangement for optimizing a transport time delay associated with a thyristor power supply which is effective for supplying power to a motor, said optimizing arrangement comprising:
- said thyristor power supply including a plurality of thyristors which are fired in a sequentially controlled manner so as to produce such power to said motor;
means for calculating a gate firing angle for a next one of said plurality of thyristors, said calculating means performing such calculation at a first predetermined time following gating of a previous one of said plurality of thyristors;
means for recalculating said gate firing angle at a second predetermined time just prior to gating of said next one of said plurality of thyristors; and
means for preventing such calculated gate firing angle of said calculating means from overriding such recalculated gate firing angle produced by said recalculating means.
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Accused Products
Abstract
A digital current control arrangement for optimizing the transport time delay of a thyristor power supply used as a source of armature current for a DC motor utilizes a coarse gate angle interrupt subroutine to perform a preliminary calculation of the gate firing angle for the next thyristor to be fired. The coarse gate angle calculation is performed at a predetermined time following the firing of a previous thyristor. A finite gate angle interrupt subroutine is also provided for recalculating the gate firing angle at a second predetermined time just prior to the firing of the thyristor. The finite and coarse gate angle interrupt subroutines both perform their respective calculations using the common parameters. A flag passing arrangement is also included in the current control arrangement and is effective to insure that the finite gate firing angle is the preferred calculation used in the firing of the next thyristor.
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Citations
17 Claims
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1. An arrangement for optimizing a transport time delay associated with a thyristor power supply which is effective for supplying power to a motor, said optimizing arrangement comprising:
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said thyristor power supply including a plurality of thyristors which are fired in a sequentially controlled manner so as to produce such power to said motor; means for calculating a gate firing angle for a next one of said plurality of thyristors, said calculating means performing such calculation at a first predetermined time following gating of a previous one of said plurality of thyristors; means for recalculating said gate firing angle at a second predetermined time just prior to gating of said next one of said plurality of thyristors; and means for preventing such calculated gate firing angle of said calculating means from overriding such recalculated gate firing angle produced by said recalculating means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A drive control arrangement for a motor powered by a thyristor power supply comprising:
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means for sensing a current reference value representative of a desired speed for said motor; means for determining a measured flow of current in said motor; means for calculating a gate firing angle for a next one of a plurality of thyristors which form said thyristor power supply, said calculating means calculating said gate firing angle as a function of said current reference value and said measured current flow; said calculating means further effective for determining a sampling time which is utilized in the performance of said gate firing angle calculation, said sampling time being representative of the difference between the occurrence of a timing measure taken during the calculation of a last gate firing angle for a previous one of said plurality of thyristors and a timing measure taken during the calculation of a present gate firing angle for said next one of said plurality of thyristors; said calculating means further being effective such that said calculation of said gate firing angle is performed in at least a first and a second stage wherein said first stage occurs at a predetermined time following the firing of said previous one of said plurality of thyristors and said second stage occurs at a second predetermined time just prior to the gating of said next one of said plurality of thyristors; and means for recalculating said gate firing angle such that said next one of said plurality of thyristors is fired thereby. - View Dependent Claims (11, 12, 13, 14)
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15. A method of optimizing a transport time delay associated with a thyristor power supply operable to supply power to a motor, said optimizing method comprising the steps of:
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determining a sampling time representative of the difference between a previous two gate angle calculations associated with two successive gate firings of a plurality of thyristors associated with the thyristor power supply; calculating a gate firing angle as a function of such sampling time, said calculating step being performed for a next one of the thyristors associated with the thyristor power supply at a first predetermined time following gating of the previously fired thyristor associated with the thyristor power supply; recalculating such gate firing angle for the next one of the thyristors at a second predetermined time just prior to the gating of such next one of the thyristors associated with the thyristor power supply; and implementing such recalculated gate firing angle such that the time between operation of said recalculating step and said implementing step is minimized. - View Dependent Claims (16, 17)
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Specification