07-04-2017, 04:22 PM
Harmonics are multiples of a fundamental frequency. In music, they are called octaves, and are generally desirable. But in the electrical power distribution system of a plant, they are not desired. An increasing number of harmonic mitigation techniques are available, including active and passive methods, and selecting the most appropriate technique for a particular case can be a complicated decision-making process. The performance of some of these techniques depends to a large extent on system conditions, while others require extensive system analysis to prevent resonance and condenser failure problems. In this paper we present a classification of the various harmonic mitigation techniques available to present a review of harmonic mitigation methods to researchers, designers and engineers dealing with energy distribution systems.
The non-linear characteristics of many industrial and commercial loads such as power converters, fluorescent lamps, computers, light dimmers and variable speed drives (VSDs) used in conjunction with industrial pumps, fans and compressors and also in air conditioning Harmonic distortion is a common occurrence in electrical networks. The harmonic currents injected by some of these loads are generally too small to cause significant distortion in the distribution networks. However, when operated in large quantities, the cumulative effect has the capacity to cause severe levels of harmonic distortion. These do not usually alter the end-user's electronic equipment as much as overloading neutral conductors and transformers and, in general, cause additional losses and reduced power factor. Large industrial converters and speed drives on the other hand are capable of generating significant levels of distortion at the common coupling point (PCC), where other users are connected to the network.
The non-linear characteristics of many industrial and commercial loads such as power converters, fluorescent lamps, computers, light dimmers and variable speed drives (VSDs) used in conjunction with industrial pumps, fans and compressors and also in air conditioning Harmonic distortion is a common occurrence in electrical networks. The harmonic currents injected by some of these loads are generally too small to cause significant distortion in the distribution networks. However, when operated in large quantities, the cumulative effect has the capacity to cause severe levels of harmonic distortion. These do not usually alter the end-user's electronic equipment as much as overloading neutral conductors and transformers and, in general, cause additional losses and reduced power factor. Large industrial converters and speed drives on the other hand are capable of generating significant levels of distortion at the common coupling point (PCC), where other users are connected to the network.