In last couple of decades due to exponential growth in semiconductor integration technology and variety of high-power rating static switches, energy conversion technologies based on power electronic interface have gained tremendous popularity. Due to massive advancement in automation technology, it has necessitated to use power electronics converter based Variable Speed Drives (VSD) for the speed control of ac and dc motors in the industries. In the modern-day industry as well as commercial entities, majority of the machinery and equipment use power electronics interface in one or the other way. In addition, the low voltage customers like modern households also use a significant amount of power electronic based devices for their daily usage. In most of the residential buildings, modern home appliances like air conditioners, refrigerators and washing machines, microwave ovens, induction cooking range, LED/LCD tv panels, LED lighting and CFL lamps, cell phones and laptops use either single stage fixed ac to fixed dc conversion or two stage fixed ac to variable ac energy conversion with the help of power electronics converters. Due to concern over environmental pollution and green-house gas emission norms, renewable energy generation has gained a lot of focus by the governments and private industries across the globe. There are various technical issues faced by the renewable energy sources while operating with the grid or in islanding mode. Majority of such issues are resolved when renewable energy source is connected to the grid through power electronics interface. At the same time, with the increase in renewable energy based electric power generation the power quality issues are further complicated due to the intermittent nature of the renewable energy generation along with use of power electronics interface. The power electronic switches operating at high frequency switching introduce switching harmonics to the system it is connected. The widespread use of power electronic devices in the low voltage network create huge amount of harmonic pollution in the network as those devices emit harmonic current and eventually increase harmonic voltage distortion in the network. The nonlinearity of the electrical equipment like motors and transformers also introduce distortion in the waveform which also contributes to harmonic pollution. With the distorted supply voltage, most of the devices produce even more harmonic current pollutions. The experiments have revealed that when the supply voltage is distorted, the devices produce significantly large amount of harmonic current pollution. In extreme cases, poor power quality because of high harmonic distortion may damage or decrease the service lifetime of the network components. Considering all these factors and detrimental consequences of the harmonic related problem in the overall low voltage network are to be taken into accounted seriously. Many standards had been devised to reach a common goal of defining power quality standards which concluded with IEEE519 standards which were first defined in 90s and revised to the latest implementation scenario in 2014 that defines all required parameters at different voltage levels in the power system.
