A Suppression Method For Inrush Current And Oscillation In Hybrid Three-Level ANPC With A Decoupling Capacitor

The hybrid three-level active neutral point clamped (HT-ANPC) converter is widely used in various industrial scenarios. In order to reduce the voltage stress of high-frequency switching transistors, the topology of HTANPC with a decoupling capacitor (HDT-ANPC) has been proposed. However, the low-frequency switching transistors in the HDT-ANPC topology will generate inrush current and oscillation at the commutation instant of the fundamental frequency. In this paper, the switching drive (SD) suppression method using the voltage difference as the reference quantity is proposed to protect components in the circuit and make the system work properly. This method dynamically increases the impedance of the circuit and it has no effect on the steady-state operation of the system. Finally, the effectiveness of the method is verified by simulation results.