Power regulation system

Claim 2

A regulation system for providing current according to a predetermined current level sequence from a multiple-phase power source one or more load elements comprising: rectifying means for connection between the multiple-phase power supply and the load elements, said rectifying means comprising a plurality of controlled switching devices each having a control gate, each of the inputs to said control switches being adapted for connection to a different phase of said power supply and each of the outputs from said control switches being connected to a common terminal which is adapted for connection to each load to provide rectified current to operate said load elements; means for providing a reference signal proportional to the desired current to flow through each of said load elements; means for providing gating signals to each of said control gates to sequentially energize the controlled switching devices; said reference signal means being connected to said gating signal means, and controlling the latter to control the phase firing time of each of said controlled switching devices to produce a load current to operate said load elements which is proportional to said reference signal.

Claim 3

Apparatus as in claim 1, including means for monitoring the actual current to each of the load elements; means for monitoring the current to the load element having the highest value of current flowing thereto; and means for comparing the value of the reference signal with the value of the current to the load element having the highest current flowing thereto and providing an error signal proportional to the difference between the two to the gate signaling means to alter the phase firing time of said plurality of controlled switching devices according to magnitude of the error signal to minimize said error signal.

Claim 4

A power supply and regulation system as in claim 1 wherein the reference signal means comprises: logic means for providing digital command signals according to the predetermined current level sequence; transmission means for receiving and relaying said digital command signals; generating means responsive to said digital command signals from said transmission means for providing an analog reference signal according to the predetermined sequence desired to the load elements.

Claim 5

A system as in claim 3 wherein the logic means comprises: a pulse operated bistable circuit; geneRating means for providing a train of pulse signals whenever said bistable circuit is set; counter means responsive to said pulse train to provide an accumulated pulse output; decoding means responsive to predetermined counter bit combinations to provide said digital command signals; said decoding means including means for providing a reset signal to said bistable circuit whenever a predetermined maximum number of pulses are accumulated in said counter means.

Claim 6

Apparatus as in claim 3 wherein said transmission means comprises: a transformer having primary and secondary windings; a secondary winding circuit comprising a switching circuit including a gate control input for shorting the secondary winding in response to a first binary input signal thereby causing a large current to flow through the primary winding, and for opening in secondary circuit in response to a second binary input signal thereby causing a small current to flow through the primary winding; a primary winding circuit comprising: a high frequency signal source for providing current through the primary winding; and means for sensing the value of the current through the primary winding and providing a first binary output signal corresponding to the first binary input signal when the current value through the primary winding is high and providing a second binary output signal corresponding to the second binary input signal when the current through the primary winding is low.

Claim 7

A system as in claim 5 having a center tapped primary winding and wherein the current value sensing means comprises: resistive impedance connected to ground to complete a current path to the high-frequency signal source; rectifying means for providing unidirectional current flow from the center tap of the primary winding through the resistive impedance; a peak detector having an input associated with the resistive impedance and an output to provide a demodulated signal; a lever detector to receive the demodulated signal and to provide an output signal whenever the demodulated signal is above a predetermined value.

Claim 8

A system as in claim 6 wherein the rectifying means comprises two diodes, one being connected between one of the terminals of the high-frequency signal source and one of the terminal of the primary winding in a direction to permit flow of current through the resistive impedance to ground during one-half of each cycle, and the second diode being connected between the other terminal of the high-frequency signal source and the other terminal of the primary winding in a direction to permit flow of current through the resistive impedance to ground during the other half of each cycle.

Claim 9

A system as in claim 5 wherein the switching circuit comprises a diode rectifier bridge and a three-layer semiconductor switching device connected to the output loop of the diode bridge.

Claim 10

Apparatus as in claim 3, wherein said transmission means comprises: a transformer having primary and secondary windings; a primary winding circuit comprising a high-frequency signal source for providing current through the primary winding; switching means to open the primary winding circuit in response to a first binary input signal and to close the primary winding circuit in response to a second binary input signal; a secondary winding circuit comprising means for providing a signal proportional to the absolute value of the current flowing through the secondary circuit; and means responsive to the absolute value of the current through the secondary winding to provide a first binary output signal corresponding to the first binary input signal whenever the absolute value of the current is substantially small and to provide a second binary output signal corresponding to the second binary input signal whenever the average absolute value of the current is high.

Claim 11

A system as in claim 9 wherein the absolute current responsive means comprises: a resistive impedancE; rectifying means coupled with the secondary winding to provide a pulsating unidirectional current through the resistive impedance; a peak detector coupled with the resistive impedance to provide a demodulated output signal.

Claim 12

A system as in claim 10 wherein the rectifying means comprises a diode bridge.

Claim 13

A system as in claim 9 wherein the primary winding includes a center tap terminal and wherein the switching means comprises: a resistive impedance with one terminal connected to the center tap terminal; rectifying means to provide direct current through the resistive impedance; switching device connected between the other terminal of the resistive impedance and ground to complete a current path to the high-frequency signal source.

Claim 14

Apparatus as in claim 1 including, a protection system comprising, first means for providing an alarm signal if the reference current signals exceed a predetermined value for longer than a predetermined time period.

Claim 15

Apparatus as in claim 13 wherein said first means comprises: integration means responsive to the reference current signals; level detection means responsive to the integrated reference current signals and for providing a first signal whenever the integrated reference current signal exceeds a predetermined value; means responsive to the first signal for providing an alarm signal.

Claim 16

Apparatus as in claim 14 including means for inhibiting the alarm signal whenever the first signal ceases.

Claim 17

Apparatus as in claim 1 including, a protection system to provide an alarm signal whenever the actual load current exceeds the desired load current for a predetermined period of time, comprising: first means responsive to the reference current signal and the actual current to the load to provide a current error signal; second means responsive to said current error signal to provide a first signal whenever the absolute value of the current error signal exceeds a predetermined value; third means responsive to said first signal for providing an alarm signal whenever said first signal is present for more than a predetermined time period.

Claim 18

Apparatus as in claim 16 wherein said third means comprises: means for integrating said first signal; level detecting means responsive to the integrated first signal to provide a second signal whenever the integrated first signal exceeds a predetermined threshold value; means responsive to the second signal for providing an alarm signal.

Claim 19

Apparatus as in claim 16 including means for inhibiting the alarm signal whenever the first signal ceases.

Claim 20

Apparatus as in claim 16 wherein said second means comprises: means for amplifying the current error signal wherein the amplifying means becomes saturated and provides a clipped error output signal whenever the magnitude of the current error signal exceeds predetermined positive and negative values; means responsive to said amplified error signal to provide a unidirectional output signal whenever said error amplifier is saturated.

Claim 21

Apparatus as in claim 1 wherein the magnitude of the direct current being applied to the load element is a function of the phase angle at which each phase output is connected, the range of phase angles extending from that which provides maximum positive voltage forcing to that which provides maximum negative voltage forcing, and having a voltage waveform characterized as having a relatively small ripple component during maximum positive voltage forcing when all three-phase outputs are operable; as having a larger ripple component during maximum negative voltage forcing when all three-phase outputs are operable; and as having relatively large ripple components at other phase angles or whenever any of the phase outputs are inoperable, including a protection system for providing an alarm signal whenever the output from one of the phase outputs becomes inoperable during maximum positive or negative voltage forcing, compRising: ripple voltage detecting means responsive to the load voltage to provide a first signal proportional to the magnitude of the load ripple voltage; enabling means for relaying the first signal whenever maximum positive or negative forcing is called for; level detection means responsive to the first signal during maximum positive and negative forcing to provide a second signal whenever the value of the first signal exceeds a predetermined threshold value indicating an inoperable phase; means responsive to the second signal to provide an alarm signal whenever the second signal is provided.

Claim 22

Apparatus as in claim 20 including means for inhibiting the alarm signal whenever the inoperable phase becomes operable.

Claim 23

Apparatus as in claim 20 including means for reducing the ripple voltage during negative voltage forcing when all phases are operable whereby the predetermined threshold value required to provide the second signal may be lowered, comprising a negative clipping circuit for clipping the monitored load voltage below a predetermined negative voltage value.