Design and Modelling for LCL Filter for Measurement of THD Reduction in Different Modular Multilevel Converters

Modular multilevel converters (M2Cs) have become an interesting and attractive topology for DC/AC conversions and vice versa. This converter is an efficient power electronic converter for adjustable speed drives, high-voltage direct current transmission, renewable energy systems and large power supplies. For drive applications, a theoretical background is presented. This paper presents the comparative analysis of M2Cs based upon measurement of the total harmonic distortion under 5-level, 7-level, 9-level and 11-level M2C. The mathematical modelling and designing of an inductor–capacitor–inductor filter is proposed at the output for the harmonic reduction. The objective of the proposed overall system is to ensure that the voltage harmonic distortion at the point of common coupling is less than 5%.