Apparatus for compensating reactive power by current-source type converter
AssigneeHitachi, Ltd.
InventorsSeiya Shima, Hiromi Inabe, Sadao Hokari
Life of this patent
Estimating the term…
Loading patent…
AssigneeHitachi, Ltd.
InventorsSeiya Shima, Hiromi Inabe, Sadao Hokari
Estimating the term…
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.degree. 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.
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,
Dependencies are inferred from the claim text.