Power balance in AC circuits

Power factor

It is energetically advantageous to operate a generator or electrical equipment if it performs the maximum work. Work in the electric circuit is determined by the active power R.
Power factor indicates how efficiently a generator or electrical equipment is used.

λ = P / S = cosφ≤1

With a decrease in the power factor, the cost of electricity consumed increases.
Ways to increase power factor
Power is maximum in the case when P = S, i.e. in the case of a resistive circuit.
The generator performs only irreversible energy conversion and does not participate in oscillatory processes of energy exchange with the electromagnetic field of the receivers, in the maximum power mode.
Consumers of electrical energy basically have an RL element replacement circuit, therefore, an increase in power factor is possible by compensating reactive power by connecting a capacitive element (QL-QC), connecting a capacitive element reduces the current in the transmission line, which reduces the cross section of the electrical wires, and this leads to savings conductive materials.
The value of the power factor in power systems depends on how competently operated electrical installations and devices.
cosφ may decrease if the units are idling or underloaded