June-Seok Lee and Kyo-Beum Lee, "Modulation Technique to Reduce Leakage Current in Transformerless Photovoltaic Systems using a Three-Level Inverter," in Proc. APEC Conf., Mar. 2013, pp. 700–705. > Paper

Transformerless photovoltaic (PV) systems are used because they have many advantages (weight, size, efficiency, etc.). However,

transformerless PV systems suffer from leakage current. The present paper proposes a modulation technique to reduce the leakage

current in transformerless PV systems using a three-level inverter. The cause of the leakage current is analyzed. The proposed

technique uses large vectors, medium vectors, and only one zero vector, and switching occurs once in a switching period. The

effectiveness of the proposed technique is verified by comparing its results with those of the space vector pulse width modulation ​

(SVM) method. The results are obtained through simulation.