On the Current Desomposition based on Instantaneous Apparent Power Vector

M. Popescu, A. Bitoleanu, M. Dobriceanu, and M.A. Popescu (Romania)


Complex apparent power, p-q theory, instantaneous active and reactive currents


This paper deals with the current space-vector decomposition in three-phase, three-wire systems based on instantaneous apparent power vector. A wide variety of approaches have been proposed to decompose the current waveform into various components in the general case of non-sinusoidal regime. Especially, the decomposition of currents into necessary and useless components is needed for the control of compensators such as active filters. Instead of Akagi’s instantaneous active and reactive currents defined in terms of real and imaginary parts of the complex apparent power, we have proposed four components of the current space-vector in terms of DC and AC components of the instantaneous powers p and q. The term of supplementary useless current vector has also been pointed out. The analysis of some case studies has shown that the current decomposition which respects the definition of the instantaneous apparent power vector is useful for compensation reasons only if the suppy voltages are sinusoidal. A modified definition of the components of the current is proposed for the operation under non sinusoidal voltage conditions.

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