A definition of the "reactive power" concept

Abstract

A definition of the "reactive power" concept needs to be clarified, since in the literature it is often given extremely vaguely, which causes difficulties in students' perception and is not entirely clear to the general public. Analysis of numerous sources shows that the physical meaning of this concept almost escapes the definitions given in these sources. Moreover, the formula by which the reactive power is calculated raises no objections. However, it does not explain the physical meaning of the concept. The need for a capacious definition that reflects the physical meaning is long overdue. Analysis of literature sources allows us to conclude that reactive power corresponds to the energy that goes from the source to the consumer and returns back, moreover, the process of circulation of this energy proceeds without dissipation. This energy is stored in inductors, keeping the current constant, and in capacitors, because they charge and discharge, keeping the voltage constant. The inductance and capacitance of the circuit consume and return reactive power. The power transferred to the inductor is stored in the magnetic field when the field expands and returns to the source when the field collapses. The power supplied to the capacitor is stored in an electrostatic field when the capacitor is charged and returned to the source when the capacitor is discharged. This power supplied to the circuit by the source is not consumed. It all returns to the source. Thus, the active power, which is the consumed power, is zero. We know that alternating current is constantly changing; thus, cycles of expansion and collapse of magnetic and electrostatic fields constantly occur. The following definition is proposed: non-dissipated electrical energy of alternating current, which excites the magnetic or electric fields, respectively, in inductive and capacitive elements and, coming from them back to the network, is called reactive power.