An Adaptive Prefiltering Method for Reduction of DC-link ripple in Cascaded NPC/H-bridge System

Cascaded NPC/H-bridge 시스템의 DC-link 리플 저감을 위한 적응 선필터링 기법

In this paper, adaptive prefiltering method is proposed for reduction of dc-link ripple in cascaded NPC/H-bridge system. Under non-linear load such as electric machine or harmonically distorted conditions, dc-link capacitor voltage with harmonics is inevitable result. In terms of reducing dc-link ripple, prefiltering method combined low pass filter with multiple second order generalized integrator is proposed. Proposed prefiltering method effectively reduces harmonics of dc-link ripple and improves characteristic of THD, simulated by using MATLAB R2014a and PSIM 9.1.4.