Stability Analysis and Parameters Design of the Voltage Source Inverter with LC Filter

Abstract

Voltage source inverters (VSI) are widely used in many applications. In this thesis, the stability of the LC-type single-phase off-grid inverter is investigated and the emphasis is focused on how to extend the effective damping region. The harmonics resonance is the main factor affecting the stability of the system. To deal with this problem, the stability of the system with passive damping is investigated. Aiming at the problem that passive damping methods introduce power loss, Active damping methods are proposed. Considering the system with traditional inductor current feedback active damping cannot be stable when resonance frequency is close to fs/6, a lag compensation method based on the all pass filter is proposed. To design the parameters more conveniently, a design guideline is given and the simulation verifies the effectiveness of this method. Traditional inductor current active damping can keep the system stable when fr