Power quality impact of energy-efficient electric domestic appliances

Electric domestic appliances are part of our daily life; they improve the quality of life. Concerning energy consumption of domestic appliances, great improvements was achieved these last years. The modern energy-efficient electric domestic appliances are electronically controlled. Generally, in a three-phase system, they constitute an unbalanced and nonlinear load. Their operation may cause power quality problems in low voltage networks. Nonlinear loads draw distorted currents from grid. Different harmonics, especially the third harmonic, in phase and neutral conductors, contribute significantly to the increase of losses in distribution networks having an important contribution to an inefficient operation of line and users. Additionally, the network pollution may decrease the reliability of line. The paper analyses the power quality perturbations produced in distribution networks by energy-efficient electric domestic operation. The conclusions are sustained by a case study.