Controlled rectifier triggering system

Claim 2

An electrical system for providing an electrically isolated direct voltage signal that is capable of controlling the forward biasing of the gate-cathode circuit of a controlled rectifier for periods of time corresponding to the pulse width of said signal comprising, a control means for determining the conduction periods of said controlled rectifier, first and second transformers each having a primary winding and a secondary winding, a source of direct voltage, a switching means connected with said source of direct voltage and said primary windings for alternately energizing said primary windings at a predetermined rate, said switching means including means controlled by said control means for determining the time period of alternate energization of said primary windings, and means connecting said secondary windings to a conductor means whereby a continuous direct voltage is developed across said conductor means by voltages induced in said secondary windings, said direct voltage having a pulse width determined by said control means.

Claim 3

The electrical system according to claim 1 where the switching frequency of said switching means is such that said primary windings are switches a plurality of times for each conduction period of a controlled rectifier as determined by said control means.

Claim 4

A trigger system for gating a plurality of controlled rectifiers of a power control system sequentially conductive comprising, a control means for determining the conduction period and frequency of occurrence of conduction periods of said controlled rectifiers, a trigger circuit for each controlled rectifier, each trigger circuit comprising first and second transformers each having a primary windings for alternately energizing said primary windings with direct current for a predetermined total time period determined by said control means and with a predetermined overlapping simultaneous energization of said primary windings, means for energizing said bias windings with direct current, the flux developed by said bias windings opposing that developed by energization of said primary windings, and means coupled to said secondary windings for developing a unidirectional voltage which is applied to the gate-cathode circuit of a controlled rectifier to gate a controlled rectifier on for periods of time determined by said control means.

Claim 5

A trigger system for gating a plurality of controlled rectifiers of a power control system sequentially conductive comprising, a control means for determining the conduction period and frequency of occurrence of conduction periods of said controlled rectifiers, a trigger circuit for each controlled rectifier, each trigger circuit comprising first and second transformers each having a primary windings for alternately energizing said primary windings with direct current for a predetermined total time period determined by said control means and with a predetermined overlapping simultaneous energization of said primary windings, means for energizing said bias windings with direct current, the flux developed by said bias windings opposing that developed by energization of said primary windings, and means coupled to said secondary windings for developing a unidirectional voltage which is applied to the gate-cathode circuit of a controlled rectifier to gate a controlled rectifier on for periods of time determined by said control means.

Claim 6

An electrical system for gating a controlled rectifier to a conductive condition for predetermined sequentially occuring time periods comprising, first and second transformers each having a primary winding, a secondary winding and a bias winding, a source of direct current, a first switching means coupled with said source of direct current and one side of said primary windings, control means coupled to said first switching means for causing said first switching means to be conductive for said predetermined time periods whereby one side of said source of direct current is connected to one side of each primary winding of said first and second transformers for said predetermined periods of time, second and third switching means connecting an opposite side of said source of direct current with respective opposite sides of said primary windings, means coupled to said second and third switching means causing said second and third switching means to be rendered alternately conductivE with a predetermined overlap in the conduction of said second and third switching and either said second and third switching means are in a conductive condition, means for energizing said bias windings with direct current, and means including a capacitor connected to said secondary windings of said transformers providing a fast rise unidirectional voltage applied to the gate-cathode circuit of said controlled rectifier which has a pulse width that substantially corresponds to the time period that said first switching means is closed.

Claim 7

An electrical system for gating a controlled rectifier to a conductive condition for predetermined sequentially occuring time periods comprising, first and second transformers each having a primary winding, a secondary winding and a bias winding, a source of direct current, a first switching means coupled with said source of direct current and one side of said primary windings, control means coupled to said first switching means for causing said first switching means to be conductive for said predetermined time periods whereby one side of said source of direct current is connected to one side of each primary winding of said first and second transformers for said predetermined periods of time, second and third switching means connecting an opposite side of said source of direct current with respective opposite sides of said primary windings, means coupled to said second and third switching means causing said second and third switching means to be rendered alternately conductivE with a predetermined overlap in the conduction of said second and third switching and either said second and third switching means are in a conductive condition, means for energizing said bias windings with direct current, and means including a capacitor connected to said secondary windings of said transformers providing a fast rise unidirectional voltage applied to the gate-cathode circuit of said controlled rectifier which has a pulse width that substantially corresponds to the time period that said first switching means is closed.

Claim 8

An electrical system for gating a controlled rectifier to a conductive condition for predetermined time periods comprising, first and second transformers, each of said transformers having a primary winding, a secondary winding and a direct-current bias winding, a first switching device, a source of direct-current, said first switching device connected between one side of said primary windings of said transformers and one side of source of direct current, control means connected with said first switching device for causing said first switching device to be rendered conductive for said predetermined periods of time, means connected with said second and third switching devices for causing said second and third switching devices to be alternately conductive with a predetermined overlap in conducting periods of said first and second switching devices, means coupling said direct-current bias windings to a source of direct current, means connected with the secondary windings of said transformers for providing unidirectional voltage having a pulse width corresponding to said predetermined time periods, and means for applying said unidirectional voltage to the gate-cathode circuit of said controlled rectifier whereby said controlled rectifier is biased conductive for said predetermined periods of time as determined by the conductive periods of time of said first switching device, the flux developed by said bias windings opposing the flux developed by said primary windings.

Claim 9

An electrical system for gating a controlled rectifier to a conductive condition for predetermined time periods comprising, first and second transformers, each of said transformers having a primary winding, a secondary winding and a direct-current bias winding, a first switching device, a source of direct-current, said first switching device connected between one side of said primary windings of said transformers and one side of source of direct current, control means connected with said first switching device for causing said first switching device to be rendered conductive for said predetermined periods of time, means connected with said second and third switching devices for causing said second and third switching devices to be alternately conductive with a predetermined overlap in conducting periods of said first and second switching devices, means coupling said direct-current bias windings to a source of direct current, means connected with the secondary windings of said transformers for providing unidirectional voltage having a pulse width corresponding to said predetermined time periods, and means for applying said unidirectional voltage to the gate-cathode circuit of said controlled rectifier whereby said controlled rectifier is biased conductive for said predetermined periods of time as determined by the conductive periods of time of said first switching device, the flux developed by said bias windings opposing the flux developed by said primary windings.

Claim 10

An electrical system for sequentially gating a plurality of controlled rectifiers to a conductive condition for predetermined periods of time comprising, a source of direct current, first and second transformers for each controlled rectifier, each of said transformers having a primary winding, a secondary winding and a bias winding, a plurality of first switching devices equal in number to pairs of transformers, second and third switching devices, means electrically connecting each first switching device between one side of a pair of primary windings of a pair of transformers and one side of said source of direct current, means electrically connecting said second and third switching devices between opposite sides of pairs of primary windings of pairs of transformers and said source of direct current, cycling means coupled to said first switching devices for causing said first switching devices to be rendered conductive in a predetermined sequence for predetermined lengths of time which correspond to the desired conduction periods of said controlled rectifiers, means connected with a said second and third switching devices for causing said second and third switching devices to become alternately conductive with a predetermined overlap in conduction periods of said second and third switching devices, means connecting said bias windings with a source of direct current, the flux developed by said bias windings opposing the flux developed by said primary windings, means electrically connecting the secondary windings of each pair of transformers to provide unidirectional signal voltages which have a pulse width corresponding to the conduction periods of said first switching devices, and means including a capacitor for applying fast rise unidirectional voltages to the gate-cathode circuits of said controlled rectifiers of a pulse width corresponding to said unidirectional signal voltage.

Claim 11

An electrical system for sequentially gating a plurality of controlled rectifiers to a conductive condition for predetermined periods of time comprising, a source of direct current, first and second transformers for each controlled rectifier, each of said transformers having a primary winding, a secondary winding and a bias winding, a plurality of first switching devices equal in number to pairs of transformers, second and third switching devices, means electrically connecting each first switching device between one side of a pair of primary windings of a pair of transformers and one side of said source of direct current, means electrically connecting said second and third switching devices between opposite sides of pairs of primary windings of pairs of transformers and said source of direct current, cycling means coupled to said first switching devices for causing said first switching devices to be rendered conductive in a predetermined sequence for predetermined lengths of time which correspond to the desired conduction periods of said controlled rectifiers, means connected with a said second and third switching devices for causing said second and third switching devices to become alternately conductive with a predetermined overlap in conduction periods of said second and third switching devices, means connecting said bias windings with a source of direct current, the flux developed by said bias windings opposing the flux developed by said primary windings, means electrically connecting the secondary windings of each pair of transformers to provide unidirectional signal voltages which have a pulse width corresponding to the conduction periods of said first switching devices, and means including a capacitor for applying fast rise unidirectional voltages to the gate-cathode circuits of said controlled rectifiers of a pulse width corresponding to said unidirectional signal voltage.

Claim 12

An electrical system comprising, a source of polyphase alternating current, a polyphasE electrical load, a converter connecting said source of alternating current and said electrical load, said converter comprising a plurality of full-wave switching circuits each of which is comprised of a plurality of controlled rectifiers, a plurality of pairs of transformers, one pair of said transformers for each controlled rectifier switching circuit, each transformer having a primary winding, a secondary winding and a bias winding, a plurality of first logic switching devices equal in number to said full-wave switching circuits, second and third switching devices, a source of direct current, means electrically connecting one side of a pair of primary windings of a pair of transformers with an opposite side of said source of direct current through said second and third switching devices logic control means connected with said first switching devices for causing said first switching devices to be rendered conductive for predetermined periods of time in a polyphase sequence, means connected to said second and third switching devices to be rendered alternately conductive with a predetermined overlap in conduction periods current, the flux developed by said bias windings opposing the flux developed by said primary windings, means electrically connecting the secondary windings of pairs of transformers in such a manner that a unidirectional signal voltage is developed which has a pulse width that corresponds the the conduction periods of said first switching devices, and fast rise trigger means including a capacitor applying unidirectional fast rise voltages to the gate-cathode circuit of a respective controlled rectifier having pulse width corresponding to said signal voltage whereby said plurality of controlled rectifiers are gated conductive for predetermined lengths of time corresponding to the conduction periods of said first switching devices.

Claim 13

An electrical system comprising, a source of polyphase alternating current, a polyphasE electrical load, a converter connecting said source of alternating current and said electrical load, said converter comprising a plurality of full-wave switching circuits each of which is comprised of a plurality of controlled rectifiers, a plurality of pairs of transformers, one pair of said transformers for each controlled rectifier switching circuit, each transformer having a primary winding, a secondary winding and a bias winding, a plurality of first logic switching devices equal in number to said full-wave switching circuits, second and third switching devices, a source of direct current, means electrically connecting one side of a pair of primary windings of a pair of transformers with an opposite side of said source of direct current through said second and third switching devices logic control means connected with said first switching devices for causing said first switching devices to be rendered conductive for predetermined periods of time in a polyphase sequence, means connected to said second and third switching devices to be rendered alternately conductive with a predetermined overlap in conduction periods current, the flux developed by said bias windings opposing the flux developed by said primary windings, means electrically connecting the secondary windings of pairs of transformers in such a manner that a unidirectional signal voltage is developed which has a pulse width that corresponds the the conduction periods of said first switching devices, and fast rise trigger means including a capacitor applying unidirectional fast rise voltages to the gate-cathode circuit of a respective controlled rectifier having pulse width corresponding to said signal voltage whereby said plurality of controlled rectifiers are gated conductive for predetermined lengths of time corresponding to the conduction periods of said first switching devices.

Claim 14

The electrical system according to claim 7 where said polyphase electrical load is a polyphase induction motor and where the output frequency of said converter can be varied to control the frequency of the input voltage to the motor.

Claim 15

An electrical system for gating a controlled rectifier to a conductive state for predetermine periods of time comprising, first and second transformers each having a primary winding, a secondary winding and a bias winding, a source of direct current, a first switching device connected between sides of said primary windings of said transformers and one side of said source of direct current, second and third switching devices connected respectively between an opposite side of said source of direct current an opposite sides of primary windings whereby a primary winding can be energized when said first switching device is closed and when one one of said second or third switching devices is closed, means for causing said second and third switching devices to become alternately conductive with a predetermined overlap in conduction, said last-name means including means for causing said second and third switching devices to have a higher switching frequency than the switching frequency of said first switching device, means energizing said bias windings with direct current, the flux developed by said bias windings opposing the flux developed by said primary windings, means electrically connecting said secondary windings of said first and second transformers to provide a unidirectional voltage the pulse width of which is a function of the conduction period of said first switching device, and means for controlling the gate-cathode circuit of said controlled rectifier in accordance with the pulse width of said unidirectional voltage whereby said controlled rectifier is gated conductive for periods of time corresponding to the conduction periods of said first switching means.

Claim 16

An electrical system for gating a controlled rectifier to a conductive state for predetermine periods of time comprising, first and second transformers each having a primary winding, a secondary winding and a bias winding, a source of direct current, a first switching device connected between sides of said primary windings of said transformers and one side of said source of direct current, second and third switching devices connected respectively between an opposite side of said source of direct current an opposite sides of primary windings whereby a primary winding can be energized when said first switching device is closed and when one one of said second or third switching devices is closed, means for causing said second and third switching devices to become alternately conductive with a predetermined overlap in conduction, said last-name means including means for causing said second and third switching devices to have a higher switching frequency than the switching frequency of said first switching device, means energizing said bias windings with direct current, the flux developed by said bias windings opposing the flux developed by said primary windings, means electrically connecting said secondary windings of said first and second transformers to provide a unidirectional voltage the pulse width of which is a function of the conduction period of said first switching device, and means for controlling the gate-cathode circuit of said controlled rectifier in accordance with the pulse width of said unidirectional voltage whereby said controlled rectifier is gated conductive for periods of time corresponding to the conduction periods of said first switching means.

Claim 17

An electric drive system for an electrically propelled vehicle the combination comprising, an alternating current generator having a polyphase output winding, said generator having a rotor driven by a prime mover of said vehIcle, a polyphase induction motor having a polyphase winding, means mechanically connecting the rotor of said induction motor with at least one driving wheel of said vehicle, a converter electrically connected between the output winding of said alternating current generator and said polyphase winding of said induction motor, said converter including a plurality of full-wave switching circuits each of which is comprised of a plurality of controlled rectifiers, a plurality of pairs of transformers, said pairs of transformers corresponding in number to said switching circuits, each of said transformers having winding, a secondary winding and a bias winding, a logic switching circuit comprised of a plurality of first switching devices, a source of direct current, means electrically connecting a respective first switching device between one side of a pair of primary winding of a pair of transformers and one side of said source of direct current, second and third switching devices, means electrically connecting said second and third switching devices between an opposite side of said source of direct current and an opposite side of pairs of primary windings of a pair of transformers, means for causing said first switching devices to become conductive in a polyphase sequence, means for causing said second and third switching devices to become alternately conductive with a predetermined overlap in conduction period, means energizing said bias windings with direct current, the flux developed by said bias windings opposing the flux developed by said bias windings opposing the flux developed by said primary windings, means electrically connecting a pair of secondary windings of a pair of transformers to provide a unidirectional voltage having a pulse width which corresponds to the conduction period of a first switching device, and means for gating said controlled rectifiers to a conductive condition for a period of time corresponding to the pulse width of said unidirectional voltage.

Claim 18

An electric drive system for an electrically propelled vehicle the combination comprising, an alternating current generator having a polyphase output winding, said generator having a rotor driven by a prime mover of said vehIcle, a polyphase induction motor having a polyphase winding, means mechanically connecting the rotor of said induction motor with at least one driving wheel of said vehicle, a converter electrically connected between the output winding of said alternating current generator and said polyphase winding of said induction motor, said converter including a plurality of full-wave switching circuits each of which is comprised of a plurality of controlled rectifiers, a plurality of pairs of transformers, said pairs of transformers corresponding in number to said switching circuits, each of said transformers having winding, a secondary winding and a bias winding, a logic switching circuit comprised of a plurality of first switching devices, a source of direct current, means electrically connecting a respective first switching device between one side of a pair of primary winding of a pair of transformers and one side of said source of direct current, second and third switching devices, means electrically connecting said second and third switching devices between an opposite side of said source of direct current and an opposite side of pairs of primary windings of a pair of transformers, means for causing said first switching devices to become conductive in a polyphase sequence, means for causing said second and third switching devices to become alternately conductive with a predetermined overlap in conduction period, means energizing said bias windings with direct current, the flux developed by said bias windings opposing the flux developed by said bias windings opposing the flux developed by said primary windings, means electrically connecting a pair of secondary windings of a pair of transformers to provide a unidirectional voltage having a pulse width which corresponds to the conduction period of a first switching device, and means for gating said controlled rectifiers to a conductive condition for a period of time corresponding to the pulse width of said unidirectional voltage.