Reactive power compensating apparatus with higher harmonic suppressing function
First Claim
1. A reactive power compensating apparatus having a higher harmonic suppressing function, comprising:
- power vector calculating means for calculating an instantaneous real power and an instantaneous imaginary power in accordance with a voltage and current of a load connected to a power system;
power calculating means for deriving higher harmonic active power components, fundamental wave reactive power components, and higher harmonic reactive power components from said instantaneous real power and instantaneous imaginary power calculated by said power vector calculating means;
a limiter for limiting the magnitudes of said higher harmonic active and reactive power components and fundamental wave reactive power components derived by said power calculating means, to values equal to or lower than respective limit values;
inverse power vector calculating means for calculating an output current command value in accordance with said higher harmonic active and reactive power components limited by said limiter and said load voltage; and
an inverter for supplying an output current controlled by said output current command value to said power system as a compensation current.
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Accused Products
Abstract
Higher harmonic power components and fundamental wave reactive power components are derived from a load voltage and current, using theory (instantaneous p-q theory) regarding instantaneous real power and instantaneous imaginary power. Gains are then obtained which make the higher harmonic power components and fundamental wave reactive power components not exceed predetermined limit values. The higher harmonic power components and fundamental wave reactive power components are respectively multiplied by the gains to obtain limited higher harmonic power components and fundamental wave reactive power components. An output current command is generated in accordance with the limited higher harmonic power components and fundamental wave reactive power components. The output current command is supplied to an inverter which in turn supplies a compensation current to the power system.
34 Citations
6 Claims
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1. A reactive power compensating apparatus having a higher harmonic suppressing function, comprising:
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power vector calculating means for calculating an instantaneous real power and an instantaneous imaginary power in accordance with a voltage and current of a load connected to a power system; power calculating means for deriving higher harmonic active power components, fundamental wave reactive power components, and higher harmonic reactive power components from said instantaneous real power and instantaneous imaginary power calculated by said power vector calculating means; a limiter for limiting the magnitudes of said higher harmonic active and reactive power components and fundamental wave reactive power components derived by said power calculating means, to values equal to or lower than respective limit values; inverse power vector calculating means for calculating an output current command value in accordance with said higher harmonic active and reactive power components limited by said limiter and said load voltage; and an inverter for supplying an output current controlled by said output current command value to said power system as a compensation current. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification