Controlling currents in parallel AC/DC converters
First Claim
1. An apparatus for converting AC voltage on first, second and third supply lines to DC voltage between positive and negative DC buses, the apparatus comprising:
- a voltage regulator providing a current command signal;
a carrier generator for generating a carrier signal;
a master converter subsystem including a master current regulator, a master PWM modulator and a master converter, the master converter including six switches arranged to form master first, second and third series switch pairs between the positive and negative DC buses, a first input node between the first master pair linked to the first supply line, a second input node between the second master pair linked to the second supply line and a third input node between the third master pair linked to the third supply line, the master regulator using the current command signal to generate master modulating signals, the master PWM modulator using the master modulating signals and the carrier signal to generate control signals for controlling the master converter switches;
a slave converter subsystem including a slave current regulator, a slave PWM modulator and a slave converter, the slave converter including six switches arranged to form slave first, second and third series switch pairs between the positive and negative DC buses, a fourth input node between the first slave pair linked to the first supply line via a first intermediate line, a fifth input node between the second slave pair linked to the second supply line via a second intermediate line and a sixth input node between the third slave pair linked to the third supply line via a third intermediate line, the slave regulator using the current command signal to generate slave modulating signals, the slave PWM modulator using the slave modulating signals and the carrier signal to generate control signals for controlling the slave converter switches; and
a common mode choke linked to the first, second and third intermediate lines to essentially eliminate common mode currents in the first, second and third intermediate lines.
1 Assignment
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Accused Products
Abstract
An apparatus for converting three phase AC supply line voltages to DC voltage on a DC bus, the apparatus including a master converter subsystem and at least one slave converter subsystem wherein each subsystem includes a current regulator, a PMW modulator and a converter, the master converter linked to the supply lines and the slave converter linked to the supply lines via intermediate lines, each regulator receiving a current command signal and generating modulating signals, each modulator using a carrier signal and modulating signals from a corresponding regulator to generate control signals to control a corresponding converter, the intermediate lines linked to a common mode choke for essentially eliminating common mode currents in the intermediate lines.
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Citations
9 Claims
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1. An apparatus for converting AC voltage on first, second and third supply lines to DC voltage between positive and negative DC buses, the apparatus comprising:
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a voltage regulator providing a current command signal; a carrier generator for generating a carrier signal; a master converter subsystem including a master current regulator, a master PWM modulator and a master converter, the master converter including six switches arranged to form master first, second and third series switch pairs between the positive and negative DC buses, a first input node between the first master pair linked to the first supply line, a second input node between the second master pair linked to the second supply line and a third input node between the third master pair linked to the third supply line, the master regulator using the current command signal to generate master modulating signals, the master PWM modulator using the master modulating signals and the carrier signal to generate control signals for controlling the master converter switches; a slave converter subsystem including a slave current regulator, a slave PWM modulator and a slave converter, the slave converter including six switches arranged to form slave first, second and third series switch pairs between the positive and negative DC buses, a fourth input node between the first slave pair linked to the first supply line via a first intermediate line, a fifth input node between the second slave pair linked to the second supply line via a second intermediate line and a sixth input node between the third slave pair linked to the third supply line via a third intermediate line, the slave regulator using the current command signal to generate slave modulating signals, the slave PWM modulator using the slave modulating signals and the carrier signal to generate control signals for controlling the slave converter switches; and a common mode choke linked to the first, second and third intermediate lines to essentially eliminate common mode currents in the first, second and third intermediate lines. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for converting AC voltage on first, second and third supply lines to DC voltage between positive and negative DC rails, the method for use with an apparatus including a master converter subsystem and at least one slave converter subsystem wherein each subsystem includes a current regulator, a PWM modulator and a converter, each regulator using a current command signal to generate modulating signals for controlling an associated modulator, each modulator using a carrier signal and corresponding modulating signals to generate control signals for controlling a corresponding converter, the master converter linked to each of the supply lines and the slave converter linked to the first, second and third supply lines via first, second and third intermediate lines, respectively, the method comprising the steps of:
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providing the same current command signal to each of the master and slave current regulators; providing the same carrier signal to each of the master and slave modulators; and essentially eliminating common mode currents on the first, second and third intermediate lines. - View Dependent Claims (9)
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Specification