METHOD AND APPARATUS FOR INFLUENCING THE OUTPUT VOLTAGES OF CURRENT SUPPLY INSTALLATIONS

• US 3,562,624 A
• Filed: 09/18/1967
• Issued: 02/09/1971
• Est. Priority Date: 09/27/1966
• Status: Expired due to Term

• Current Assignee: Donati Franco, Tortelli Gianfranco, Werner Ullman
• Original Assignee: Donati Franco, Tortelli Gianfranco, Werner Ullman
• Inventors: Ullman, Werner, DONATI FRANCO, TORTELLI GIANFRANCO
• Application Number:
  US04/668,619
• Time in Patent Office: 1,240 Days
• US Class Current: 363/72
• CPC Class Codes: H02J 3/26 Arrangements for eliminating or reducing asymmetry in polyphase networks
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 7/48 using discharge tubes with control electrode or semiconductor devices with control electrode
• CPC Class Codes: Y02E 40/50 Arrangements for eliminating or reducing asymmetry in polyphase networks

Abstract

A method and apparatus for influencing or controlling the vectors of output voltages from a direct-current supply device feeding a multiconductor alternating-current transmission system. The total voltage vector for each conductor is generated from two partial voltage vectors. Control of the magnitude of the total voltage vector is effected by phase-shifting the partial voltage vectors, each partial voltage vector being phase-shifted through the same angular magnitude but in opposite angular direction. In this manner, the total voltage vector for each conductor is maintained in a constant phase position even during automatic regulation and in the presence of an asymmetrical load.

Claims

1. A method for producing multiphase electric power comprising the steps of:

providing a source of direct-current power;

inverting the direct-current power to provide two wave components for each phase of the multiphase output;

controlling the two wave components such that the wave components are displaced a variable amount by equal phase angles in opposite phase directions, the displacements being considered relative to a reference phase angle; and

automatically maintaining the equality of the phase angle displacements.

2. A method for producing multiphase electric power, said method comprising the steps of:

providing a source of direct current voltage;

inverting the direct current voltage under the control of ignition pulses to provide two voltage vector components for each output power phase;

displacing the ignition pulses for one of the vector components in one phase direction to a variable extent and displacing the ignition pulses for the other vector component in the opposite phase direction to an equal extent, both displacements being considered relative to a reference phase angle; and

, automatically maintaining the equality of both phase displacements.

3. A method as defined in claim 1, wherein the two wave components for each output phase are combined to generate an output voltage vector of variable magnitude and constant phase.

4. A method as defined in claim 2, wherein the two wave components for each output phase are combined to generate an output voltage vector of variable magnitude and constant phase.

5. A method as defined in claim 1, wherein the output power is produced in the presence of an asymmetrical load and is supplied thereto by means of a multiconductor transmission system, each of the output phases being supplied to a respective conductor of the system.

6. A method as defined in claim 1, wherein the reference phase angle defines a displacement which is the same in direction and extent for both wave components and is constant for each of the output power phases.

7. A method as defined in claim 2, wherein the reference phase angle defines a displacement which is the same in direction and extent for both wave components and is constant for each of the output power phases.

8. An apparatus for supplying multiphase electric power, said apparatus comprising:

direct current input means, output means for the supply power having a plurality of phases, inverter means for converting said input direct current into two wave components for each of the phases, and coNtrol means for displacing said two wave components to a variable extent by equal phase angles and opposite phase directions and for automatically maintaining the equality of the phase angle displacements, both of the displacements being considered relative to a reference phase angle.

9. An apparatus for supplying multiphase electric power, said apparatus comprising:

direct current input means, output terminal means for the supply power having a plurality of phases, inverter means controlled by ignition pulses for converting said input direct current into two voltage vector components for each of the phases, and control means for generating said ignition pulses such that said ignition pulses for one of the voltage vector components are displaced in one phase direction to a variable extent, and such that said ignition pulses for the other of said voltage vector components are displaced in the opposite phase direction to an equal extent, and for automatically maintaining the equality of said phase displacements, both displacements being considered relative to a reference phase angle.

10. An apparatus as defined in claim 8, further including means for each output phase for combining the two components to generate an output voltage vector of constant phase and of magnitude variable by said control means.

11. An apparatus as defined in claim 9, further including means for each output phase for combining said two components to generate an output voltage vector of constant phase and of magnitude variable by said control means.

12. An apparatus as defined in claim 9, wherein aid inverter means are controlled by ignition pulses generated by said control means, said control means comprising a multivibrator, oscillator means for supplying control impulses to said multivibrator, and differential amplifier means for providing an error signal indicative of the difference between a desired load voltage magnitude and the actual load voltage magnitude and the actual load voltage magnitude and for applying the error signal to said multivibrator to cause a phase shift of said ignition pulses of each control means relative to the control impulses of said oscillator means.

13. An apparatus as defined in claim 12, wherein two inverter means are provided for each of said output phases, one control means being provided for supplying to one of said inverter means ignition impulses displaced in one phase direction, another of said control means supplying to the other of said inverter means ignition impulses displaced by an equal amount in the opposite phase direction, both displacements being relative to a reference phase angle.

14. An apparatus as defined in claim 13, wherein said reference phase angle defines a 90* phase displacement.

15. An apparatus as defined in claim 13, wherein each of said inverter means includes four control rectifiers arranged in pairs, each of said control means including two ignition circuits, each of said ignition circuits being connected to a respective one of said pairs of control rectifiers, and wherein each of said control means includes a monostable multivibrator coupled to a Schmitt-trigger and a flip-flop to control one of said ignition circuits.