Research on modular multi-level converter control based on passivity theory

Abstract

Abstract All In view of the poor dynamic performance of the conventional PI control method in modular multilevel converter (MMC) systems, an up-to-date control strategy using passive theory is proposed. First, the topology of the system and its mathematical model are presented, then its Euler-Lagrange (EL) model is developed and its passivity is proved. Next, the dq-axis component of the current is chosen as the state variable to derive the passivity-based control (PBC) law and from this, the current passivity controller is designed. Simulation shows that compared with conventional PI control, the PBC in this paper can respond quickly to the change of current or power under different operating conditions, with good harmonic characteristics and better dynamic characteristics.