Power supply assembly with an inverter for creating N-phase alternating current

The arrangement (MF) has N-phase alternating current (AC) transformer (2) comprising primary windings (211-213) connected in a polygon. A vector sum of voltages present at multiple secondary windings (222, 223) is zero when the transformer is idle. A vertex of the polygon formed by the primary windings is connected with a corresponding phase conductor terminal of an inverter (12) via capacitors (C11-C13). Voltage across multiple secondary windings is discretely or continuously adjustable. The capacitors having an adjustable capacitance are provided in series to the secondary windings. The inverter is an H-bridge with power transistors i.e. IGBTs (121). An independent claim is also included for a reactor for producing polysilicon.