三相回路の瞬時有効無効電流および瞬時有効無効電力の新しい定義とその応用 [in Japanese] A New Definition of Instantaneous Active-Reactive Current and Power Based on Instantaneous Space Vectors on Polar Coodinates in Three-Phase Circuits [in Japanese]
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Conventionally, the active, reactive and apparent powers in three-phase circuits have been defined by extending the concept based on the RMS values of voltage and current with respect to time in single-phase circuits. Applying the definition based on single-phase circuits to three-phase systems with non-sinusoidal conditions has resulted in many options in the methods of power properties description, interpretation and compensation, and this has led to a controversy on which method should be chosen, or on how power quantities should be defined. This paper proposes a new definition of the instantaneous active-reactive current and power based on instantaneous space vectors on polar coordinates in three-phase circuits. The instantaneous active-reactive power and current are defined in the voltage-current vector plane without any special fictitious power. The new definition proposed here leads to the same formulas as the conventional ones. The authors claim that this is a great advantage of the new definition. Comparing it to the p-q theory, we discuss the new definition in detail. It is shown that using the new definition one is able to calculate the instantaneous active-reactive power and current directly from the voltage and current space vectors. The new definition, thus, offers a lucid concept of electric power in three-phase circuits. Using digital simulation, an application example is shown to confirm the validity and practicability of the new definition.
- IEEJ Transactions on Sensors and Micromachines
IEEJ Transactions on Sensors and Micromachines 117(2), 182-188, 1997-02
The Institute of Electrical Engineers of Japan