Title |
Reduction of Grid Current Harmonic Distortion through a 6th Harmonic Control Method in Grid-Connected Three-Level NPC Inverters |
Authors |
신지욱(Sin, Jiook) ; 박영수(Bak, Yeongsu) ; 박성수(Park, Seong-Soo) ; 이교범(Lee, Kyo-Beum) |
DOI |
https://doi.org/10.5370/KIEE.2017.66.5.778 |
Keywords |
Grid-connected inverter ; Three-level NPC inverter ; All-pass filter ; Coordinate transformation |
Abstract |
This paper presents a control method for reducing the distortion of the grid current at a grid-connected three-level neutral point clamped (NPC) inverter. The grid current is distorted from the 5th and 7th harmonic components in the stationary frame current also the 6th harmonic component in the synchronous frame current. In this paper, the 6th harmonic component on synchronous frame is controlled by using all-pass filters (APFs) and proportional integral (PI) controllers for distortion of the grid side. When transformed the 6th harmonic component is controlled, the 5th and 7th harmonic components are reduced. The validity of the proposed control method is verified by simulation and experiment results using a 25kW three-level NPC inverter. |