Small Packaging Technique for a Converter of an Iron and Steel Drive System

Abstract

This paper proposes a small packaging technique of an iron converter for iron and steel drive system. First, the following measure is applied to decrease the circuit inductance in order to remove the snubber circuit. A smoothing capacitor is moved near an Insulated-Gate Bipolar Transistor (IGBT) unit by splitting the capacitance of a capacitor. A clamp diode is inserted between two IGBTs, and the common-bus is widened. Thus, the opposite effect becomes large, and the inductance decreases. Second, we propose a structure to maintain the current balance for many IGBT units to satisfy the converter capacity. By using these measures, the proposed structure decreases the circuit inductance to 67% that of the conventional one, and the current balance ratio become less than 13%.