Overload Capability of the Modular Multilevel Matrix Converter for Feeding High Torque Low Speed Drives

In drive systems, the semiconductors of conventional converters must be dimensioned for the maximum torque. This results in a converter oversizing even for short time overload requirements near standstill, e.g. for mills in the mining industry. In contrast, the Modular Multilevel Matrix Converter (M3C) is characterized by the ability to share the installed switching power between the input and output side. Hence an overload capability up to 200% of the nominal value can be reached at low speeds without additional efforts. This paper explains how the overload capability is used and analyzes the overload torque limits in the whole speed range.