Thus, reactive power is not converted into other forms of power, does not require for their production costs of other forms of energy, not does work, so purely conventional, in fact, only for convenience, called the power. Despite the fact that the active power, and hence the fuel at the production of reactive power is not consumed directly, yet transfer it to an electric network is active energy costs that are borne by the active energy generators (due to the additional fuel consumption). Moreover, the transfer of reactive power loads electrical networks and equipment installed in them, thus depriving some of their bandwidth. For the calculation of modes in chains of sinusoidal current, the analysis of production and consumption of reactive power in electrical systems, reactive power is a very convenient feature, so it is widely used in practice. This is clearly illustrated by the above data on changes in the flow of reactive power (a) voltage and phase shift of current and voltage (b) in the system of power: bus stations – bus waiting for the consumer electrical substation sites A-D of the transfer. These data were obtained by measurements on a number of industrial enterprises in the hours of peak load of the most loaded winter day 2. Figure 1 denotes: Qr, Qn, qpb, qph – the value of reactive power at generator buses 6 20 kV substation buses waiting 6 10 kV, the high-and low-voltage demand for power; AQn, AQji, AQ2 _ loss of reactive power step-up transformer, power lines, in step-down transformers, respectively; ua, 11B, ub, Ur and fa, fb, fv, fg _ tension and shear angles between voltage and current at nodes A, B, C, D, the transmission system, respectively. .