Integration of DC-Bypass and Active Clamping Technique to Reduce Leakage Current in Full-Bridge Single-Phase Grid-Connected Inverter

Abstract

Due to its advantages over transformer based inverters, transformerless grid-tied inverters are currently one of the most important requirements in the solar industry. Yet, the problem of leakage current between the solar panel and the grid must be solved, and total harmonic distortion should be reduced further by new topologies to increase the efficiency of the grid-tied transformerless inverter. DC bypass and NPC techniques alone are found to be effective in decreasing the common mode current. While the integration of the two will yield better performance. This paper presents a new leakage current reduction technique using the combination of DC-bypass and active neutral point clamping technique in the conventional H5 GTI. The presented inverter is simulated in the MATLAB tool. The analysis indicates that the freewheeling current of the presented topology is 8.5 mA which is considerably lesser than the conventional H5 Inverter. Also, the THD after filtering is 2.6% and the theoretical calculations show that the efficiency of the inverter is 97.54%.