Apparatus for compensating reactive power by current-source type converter
First Claim
1. In an electric system in which a converter load circuit including a current-source type three-phase converter and a general purpose load circuit including conventional three-phase loads are connected in parallel to a three-phase power supply source,an apparatus for compensating a reactive power supplied to said general purpose load circuit be means of said converter circuit, comprising:
- first means for determining a first value selected in conjunction with output current control of said converter so that said converter produces a desired output current;
second means for generating a signal related to the instantaneous reactive power supplied to said general purpose load circuit;
third means for determining a second value for compensating said instantaneous reactive power on the basis of said signal related to said instantaneous reactive power; and
fourth means for controlling switching elements of said current-source type converter on the basis of a control factor calculated from said first and second values.
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Accused Products
Abstract
A first apparatus for determining instantaneous reactive currents to determine instantaneous reactive currents in every phase of a three-phase load. Three phase current signals corresponding, respectively, to phase currents of the three-phase load supplied from a three-phase power-supply source are multiplied with sinusoidal wave signals of three phases, each of which has a phase difference of 90° relative to the corresponding phase voltage of the three-phase power supply source to obtain the products for three phase, respectively, which products are added together to produce a sum signal. The instantaneous reactive currents mentioned above are determined on the basis of the sum signal and the three phase sinusoidal wave signals. A second apparatus for compensating the reactive power of the three-phase load by means of a converter load circuit including a current-source type three phase converter connected in parallel with the three-phase load by making use of the instantaneous reactive currents of the three-phase load determined by the first mentioned apparatus.
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Citations
4 Claims
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1. In an electric system in which a converter load circuit including a current-source type three-phase converter and a general purpose load circuit including conventional three-phase loads are connected in parallel to a three-phase power supply source,
an apparatus for compensating a reactive power supplied to said general purpose load circuit be means of said converter circuit, comprising: -
first means for determining a first value selected in conjunction with output current control of said converter so that said converter produces a desired output current; second means for generating a signal related to the instantaneous reactive power supplied to said general purpose load circuit; third means for determining a second value for compensating said instantaneous reactive power on the basis of said signal related to said instantaneous reactive power; and fourth means for controlling switching elements of said current-source type converter on the basis of a control factor calculated from said first and second values. - View Dependent Claims (2, 3, 4)
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Specification