Harmonic Analysis of Addis Ababa Light Rail Transit Traction Converters

No Thumbnail Available



Journal Title

Journal ISSN

Volume Title




Traction power system is the main area of industrial sector where the application of power electronic technology is widely used. The uses of these devices create harmonics that cause a serious problem on the proper operation of the system. There have been different corrective methods proposed by different researchers. Among them, the AC side passive filters that provide low resistive path to eliminate the harmonics; and the active filter that produce harmonic currents in equal magnitude and 180 0 out of phase to suppress it, are the widely discussed ones. This thesis provides the harmonic analysis of Addis Ababa Light Rail Transit (LRT) traction system. The analysis is performed on the Lideta rectifier substation. The traction system is modelled using Matlab/Simulink environment. Based on the data obtained from Ethiopian Railway Corporation (ERC), simulation is carried out and compared with the IEEE standard limits. Taking into consideration the cost and simplicity of the operation, single tuned filters tuned at 11 th and 13 th harmonics and high pass filter adjusted for higher harmonics currents are designed for the AC side, and LC filter is proposed for the DC side of the system. The simulation result comes with significant reduction in harmonic distortion. The Total Harmonic Distortion (THD) is reduced to 0.80% for the current and to 0.33% for voltage, which is far below the 5% limits of IEEE standard. In addition to that the system power factor is improved from 0.77 to 0.99, which avoids the installation of power factor corrector.



Traction power system, converters, harmonic analysis, harmonic filters