One of the main problems of electrical power quality is to ensure a constant power ?ux from the supply system to the receiver, keeping in the same time the undisturbed wave form of the current and voltage signals. Distortion of signals are caused by nonlinear or time varying receivers, voltage changes or power losses in a supply system. The wave-form of the voltage of the source may also be deformed. This study seeks the optimal current and voltage wave-form by means of an optimization criteria. The optimization problem is de?ned in Hilbert space and the special functionals are minimized. The source inner impedance operator is linear and time-varying. Some examples of calculations are presented.
This article aims to explain the capability of describing three-phase systems powered from the source with asymmetrical nonsinusoidal voltage waveforms. Indicating the physical components of the currents associated closely with specific physical phenomena facilitates separating the unbalanced components from the active and reactive ones. All those currents, excluding the active current and the scattered current, contribute to the existing unbalanced and reactive power. This article presents the decomposition of currents based on the Currents’ Physical Components Theory. When decomposing currents, it is assumed that the load is linear and unchanging in time, and the voltage supply is asymmetrical and nonsinusoidal.
The article presents the essentials of reactance compensation of unbalanced loads in three-phase four-wire systems powered by a sinusoidal and asymmetrical voltage source. The whole of compensation and symmetrization is based on the Currents’ Physical Components (CPC) theory. Reactance compensation, i.e. compensation based solely on inductors and capacitors, in four-wire systems requires the device to be included in a star (Y) structure in order to compensate for the reactive current (reactive power) and the current at the neutral conductor caused by zero sequence asymmetry, and for the device in a delta (∆) structure to allow compensation of the reactive current (reactive power) and current, causing asymmetry of the negative sequence.