<p>A converter module comprises a heat sink (31) and a semiconductor phase mounted on the heat sink (31). The semiconductor phase comprises a pair of semiconductor modules (32) having an AC busbar (AC) connected to the emitter (2) of one semiconductor module and the collector (1) of the other semiconductor module (32) and a pair of DC busbars connected respectively to the remaining collector (1) and emitter terminals of the pair of semiconductor modules. The AC busbar (AC) is connected to form a substantially symmetrical low inductance system. By providing symmetrical connection to the semiconductor modules it is assured that all components are loaded equally.</p><p>The converter may comprise 12 IGBT modules (32) configured in different arrangements according to the output required. To improve reliability and operation the modules are arranged in an enclosed housing with the gate drives shielded from the semiconductor elements by the heat sink.
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