A Novel 10kV Three-Level Active Neutral Point Clamped Converter with Series-Connected 1.7kV IGBT-Based Modular Switches

Abstract

The demand for 10 kV converters is continuously increasing in modern power systems and industrial applications, such as medium-voltage (MV) ac-dc distribution network interconnections and MV drives. Although neutral-point-clamped converters are extensively employed in MV scenarios, their voltage ratings are typically limited by available power devices, making it difficult to meet the 10 kV requirement. To address this limitation, this paper proposes a novel 10kV three-level active neutral point clamped converter with series-connected modular switches (MSs) based on 1.7 kV IGBTs. The topology minimizes costs by employing two types of MSs in different arms and integrates bypass switches for redundancy and fault-clearing ability. A comprehensive voltage balancing control scheme is developed for these MSs to overcome the inconsistency of series-connected devices. To verify the effectiveness of the proposed topology and control, the hardware implementation of MSs and the simulation of a 10 kV/10 MVA converter are demonstrated.