Abstract
In this chapter various harmonic sources and their effect on the distribution network and its mitigation procedures are discussed. In the distribution network, electrical power is mostly utilized for our daily activity. However, the quality of power in the distribution network is affected by different disturbances. The distribution power quality problems deteriorate the performance of the system. One of the disturbances of the distribution network is harmonic distortion. Disturbances not only produce excessive heat in the devices and appliances used in the daily life of human beings, but also reduce the life of the appliances. Finally, the harmonic distortion mitigation by using active power filter, space vector pulse width modulation, dynamic voltage restorer, voltage phase shift, and fuzzy logic controller is discussed.
TopIntroduction
Current or voltage having frequency that is the numerical multiple of the fundamental frequency at which the supply system is planned to perform i.e. 50 or 60 Hz is called harmonics. Harmonic current produce from the nonlinear loads and it caused harmonic of the drop voltage that is transmitted through the distribution network systems. It depends on the harmonic impedance of the scheme. Inter harmonics are harmonics in currents or voltages and has frequency but they are not the multiple of the source frequency (Pogaku et al. 2006).
Traditionally, the distribution network of electrical power system has to address harmonics because the distribution system users are typically planned for the linear supply (Alhelou et al., 2019; Makdisie et al., 2018; Alhelou et al., 2018; Alhelou et al., 2016; Haes Alhelou et al., 2019; Njenda et al., 2018). With the utilization of different speed drives and the power electronics converters, needed in industries, some order harmonic current are being inserted into the electrical distribution networks (Khan et al., 2019; Kifle et al. 2018; Khan et al., 2018; Khan et al., 2017; Banteywalu et al., 2019; Anteneh et al., 2019; Molla et al., 2019, Molla et al., 2018, Jariso et al. 2018). There are important methods which are broadly utilized to reduce the harmonic currents in the power supply. The harmonics can be described by the following equation depicted below.
(1)Where, fh represents the hth harmonics and fac represents the fundamental frequency of the system.
The following equations are represented for the sinusoidal current and voltage that’s depend on the time‘t’ as explained (Singh et al. 2012).
(2)(3) Key Terms in this Chapter
Distributed Generation: It is an approach that employs small-scale technologies to produce electricity close to the end users of power.
Total Harmonic Distortion (THD): It is a measurement of the harmonic distortion present in a signal and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency.
Hybrid Filter: It combines a number of passive and/or active filters and their structure may be of series or parallel topology or a combination of the two.