Current harmonics and commercial losses in smart grids

The paper presents some results of investigations of commercial losses in power networks with consumers, which are sources of current harmonics. It is shown that the active power losses in transformers, which supply such consumers, are the commercial losses of the power systems. The values of the commercial losses versus the magnitudes of the total harmonic current distortion coefficient and of the coefficient K-factor are estimated. It turns out that in many cases these losses exceed 1% of the power or energy consumption. To improve the efficiency of power systems and to reduce their commercial losses, it is suggested to take into account these losses, when estimating the balance of the produced and the consumed energy, by calculating them or by installing active energy meters at the primary side of the power system transformers of nonlinear loads.