Regulated electrical inverter system

Claim 2

A regulated electrical inverter system comprising: a. a D-C power supply providing both positive and negative D-C voltage supply; b. a D-C voltage transformation circuit energized by said D-C power supply and including positive and negative voltage transformation means having like voltage transformation ratios substantially less than one whereby their D-C voltage outputs are proportioned to but substantially lower than their D-C voltage inputs from said supply; c. a dual inverter circuit comprising a pair of inverters having positive and negative input polarities from said D-C voltage transformation circuit and including means for summing their respective outputs in a manner such that when their relative phases are oppositely shifted the summed output adjusts in a direction and to an extent determined by the phase shift; d. a load having applied thereto the summed output of said inverters; e. a rectifier bridge connected to provide feedback paths from the output of each of said inverters to the positive and negative voltage inputs to said D-C voltage transformation circuit whereby power is fed back through said rectifier bridge whenever the output voltage of either inverter exceeds the D-C supply input voltage of corresponding polarity; and f. control means responsive to a load power condition for oppositely shifting the relative phases of said inverters for controlling their summed oUtput to said load.

Claim 3

An inverter system as defined in claim 1 wherein said D-C voltage transformation circuit comprises a pair of time ratio controlled D-C choppers and means for operating said choppers at constant time ratio and frequency.

Claim 4

An inverter system as defined in claim 2 wherein said D-C choppers and said dual inverters each comprise gated solid state switching devices, and further including means for generating constant frequency trigger signals for gating the switching devices both of said D-C choppers and of said dual inverters.

Claim 5

An inverter as defined in claim 3 further including means responsive to a load power condition departure from normal for disabling said trigger signal generating means.

Claim 6

An inverter as defined in claim 3 wherein said means for generating constant frequency trigger signals for gating the switching devices of said dual inverters comprise means for time shifting the gating signals to the switching devices of one inverter with respect to those to the other, to thereby oppositely shift the relative phases of the inverters for adjusting their summed output.

Claim 7

An inverter as defined in claim 1 further including rectifier means connected between the inverter output and the load for D-C supply thereto, filter capacitor means for smoothing D-C flow from said rectifier means to said load, and current sensor means responsive to filter capacitor current flow for providing a load demand signal constituting the load power condition input to said control means.

Claim 8

An inverter as defined in claim 6 wherein said control means further includes means for integrating said load demand signal to derive an anticipation signal, and means responsive to said anticipation signal to adjust the relative phase of the outputs of said dual inverters to thereby control their summed output.

Claim 9

An inverter as defined in claim 7 wherein said control means further includes means directly responsive to said load demand signal to disable said dual inverters in the event said load demand signal exceeds a predetermined level indicative of a load short.

Claim 10

A regulated electrical inverter system comprising: a. D-C power supply means providing both positive and negative polarity supply; b. D-C voltage transformation means including positive and negative polarity voltage transformation circuits each accepting input of a D-C voltage of appropriate polarity from said power supply means and providing a D-C output of like polarity but of substantially lower voltage level; c. dual inverter circuits having a common D-C power supply input through said voltage transformation means and each comprising gated solid state switching devices operable when periodically gated to convert D-C voltage input thereto to a cyclically varying output, said inverters further comprising means for summing their respective outputs to produce a summed output of magnitude dependent on the phase relationship therebetween; d. a load having applied thereto the summed output of said inverters; e. a rectifier bridge connected to provide feedback paths from the output of each of said inverters to the positive and negative voltage inputs to said D-C voltage transformation circuit whereby power is fed back through said rectifier bridge whenever the output voltage of either inverter exceeds the D-C supply input of corresponding polarity; f. gating signal means for said inverter switching devices including clock means, means responsive thereto to output trigger signals at substantially constant frequency, and gate generator means responsive to said trigger signals to apply gating signals to said inverter switching devices; and g. control means responsive to a load power condition for time shifting said gating signals as applied to the switching devices of one inverter with respect to those to the other, for controlling the division of inverter output power as between said load and said feedback to the D-C supply to thus proVide load power regulation.

Claim 11

A regulated electrical inverter system comprising: a. D-C power supply means providing both positive and negative polarity supply; b. D-C voltage transformation means including positive and negative polarity voltage transformation circuits each accepting input of a D-C voltage of appropriate polarity from said power supply means and providing a D-C output of like polarity but of substantially lower voltage level; c. dual inverter circuits having a common D-C power supply input through said voltage transformation means and each comprising gated solid state switching devices operable when periodically gated to convert D-C voltage input thereto to a cyclically varying output, said inverters further comprising means for summing their respective outputs to produce a summed output of magnitude dependent on the phase relationship therebetween; d. a load having applied thereto the summed output of said inverters; e. a rectifier bridge connected to provide feedback paths from the output of each of said inverters to the positive and negative voltage inputs to said D-C voltage transformation circuit whereby power is fed back through said rectifier bridge whenever the output voltage of either inverter exceeds the D-C supply input of corresponding polarity; f. gating signal means for said inverter switching devices including clock means, means responsive thereto to output trigger signals at substantially constant frequency, and gate generator means responsive to said trigger signals to apply gating signals to said inverter switching devices; and g. control means responsive to a load power condition for time shifting said gating signals as applied to the switching devices of one inverter with respect to those to the other, for controlling the division of inverter output power as between said load and said feedback to the D-C supply to thus proVide load power regulation.

Claim 12

An inverter system as defined in claim 9 wherein said D-C voltage transformation circuits comprise time ratio controlled D-C choppers including gated solid state switching devices, and wherein said trigger signals also are applied to said choppers for operation thereof with fixed time ratio and at the same frequency as said inverters.