Currents’ Physical Components (CPC) in systems with semi-periodic voltages and currents

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There are situations in electrical distribution systems where voltages and currents cannot be regarded as periodic quantities. They could be non-periodic. Nonetheless, properties of electrical systems confine this non-periodicity of voltages and currents to a particular sub-set of nonperiodic quantities, referred to as semi-periodic quantities in this paper. The paper presents the concept of semi-periodic quantities and defines major functionals, such as the running active power, the running rms value, the scalar product and the running complex rms (crms) value of quasiharmonics, needed for describing electrical systems with such voltages and currents in power terms. A recursive approach to calculation of these functionals was presented as well. The paper presents fundamentals of the Currents’ Physical Components (CPC) – based power theory of systems with semi-periodic voltages and currents. An application of the semi-periodic concept to a load current decomposition in single-phase circuits with linear loads and with harmonics generating loads is presented as well. The paper presents also a concept of extrapolation of CPC into the closest future, which enables quasi-instantaneous generation of control signals for switching compensators.

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Przeglad Elektrotechniczny

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