Title |
A study on the DC Link Voltage Unbalance Improvement method of Single phase 3-Level NPC Back to back Converter |
Authors |
함정수(Jung-Soo Ham) ; 민명환(Myung-Hwan Min) ; 안태풍(Tea-Pung An) ; 이태훈(Tea-Hoon Lee) |
DOI |
https://doi.org/10.5370/KIEE.2024.73.3.607 |
Keywords |
3-Level NPC; DC Link Voltage Unbalance; Electric railway system; RPC |
Abstract |
This paper proposes an algorithm to solve the DC Link voltage unbalance problem in a single-phase three-level converter used as a power compensation device for electric railways. 3-level back-to-back converter was linked to the output terminals of the M (Main) phase and the T (Teaser) phase. The T-phase converter transmits power to the system, and the M-phase converter controls the DC Link to maintain the reference value, at this time, a difference occurs between the upper and lower capacitors. DC Link Voltage Unbalance must be balanced because it shortens the device life and cannot control the desired control. In order to verify the performance of the proposed DC Link voltage unbalance improvement algorithm, simulation and experiment were conducted on PSCAD simulation and 5kVA RPC (Railway Power Conditioner) simulator. The effect of the DC Link voltage unbalance improvement algorithm proposed was verified by reducing the voltage unbalance after applying the algorithm. |