Development of A Low Cost Active Power Filter to Suppress Neutral Current Harmonics in Three-Phase Four-Wire System JANG MIN SOO DEPARTAMENT OF CONTROL AND INSTRUMENTATION ENGINEERING SEOUL NATIONAL UNIVERSITY OF TECHNOLOGY

Development of A Low Cost Active Power Filter to Suppress Neutral Current Harmonics in Three-Phase Four-Wire System JANG MIN SOO
DEPARTAMENT OF CONTROL AND INSTRUMENTATION ENGINEERING SEOUL NATIONAL UNIVERSITY OF TECHNOLOGY


Three-phase four-wire electrical distribution systems are widely employed in manufacturing plants, commercial and residential buildings. Due to the nonlinear loads connected to the distribution system, the neutral conductor carries excessive harmonic currents even under balanced loading since the triplen harmonics in phase currents do not cancel each other. This may result in wiring failure of the neutral conductor and overloading of the distribution transformer. This paper proposes a reduced rating active power filter to suppress neutral current harmonics in three-phase four-wire electrical distribution systems. The proposed scheme employs a single-phase inverter connected in series with the neutral conductor and a -Y transformer connected in parallel with the load. The proposed active filter eliminates neutral current harmonics while it does not affect the fundamental current due to unbalanced loading. The VA rating of the inverter is significantly reduced since only fundamental current due to unbalanced loading could flow through the inverter switch. The experimental results on a prototype validate the proposed control approach.
LINK PAPER
https://copy.com/VEbQ8vgFzQ6xAXrG