Power module as the basic AC - DC - AC single-phase inverter circuit, single-phase thyristor rectifier diodes plus a three-phase full-bridge, can be controlled by a thyristor controlled rectifier into a tributary of the exchange, through the IGBT inverter bridge sine SPWM control, single-phase AC output is obtained. On each power module structure and electrical properties completely consistent, interchangeable. (Single type of spare parts)