Analysis of power quality improvement in smart grids

Electrical distribution system is designed to operate in sinusoidal mode, but the voltage and current waveforms shows distortion compared to the sinusoidal mode. Current technology development, which results in an increasing adoption of the local generation and storage capacities, is pushing towards the adoption of smart grid paradigm. An effective technical solution for enforce limitation of various types of power quality (PQ) disturbance is based on power electronics in order to increase energy transmission capacity, improve voltage stability and dynamic behavior, control power flow and ensure a better power quality at distribution inside accepted boundaries. The objectives of this paper is to assess the harmonic disturbances present into a real smart grid, and to suggest a solution to maintain the operation of the distribution system with photovoltaic (PV) plant and electrical cars within PQ limits imposed by standards. A general analysis was addressed, in order to identify the current state-of-the art of smart grid and harmonic filters and their influence on power quality. An example was designed using ETAP software, starting from a real electric distribution system in order to build a general image of corresponding PQ issues. The solutions found for this technical issues are presented with their influence on electrical current and voltage and harmonic specter.