Power supply device making power semiconductor device form series valve group

A power supply device making a power semiconductor device form a series valve group is disclosed. A power supply which is in a sine curve voltage source form is connected to an output terminal of a coupling transformer. A series loop of a power transformer primary side winding appears as a form that a lead which is from high-voltage insulation passes through a magnet ring of a power transformer. A reactor is connected to an output terminal of the power supply through the series loop of the power transformer primary winding. A compensation capacitor is directly connected to a secondary winding of the coupling transformer. A lead core from the high-voltage insulation is connected with a central point of a series valve group loop formed by the power semiconductor device. Under the circumstance, the insulation between the primary winding and the secondary winding of the coupling transformer of the power supply must be a maximum potential relatively to the valve group of the ground. A basic insulation load on a valve group component is undertaken by the coupling transformer. A partial discharge level generated by a voltage between the lead from the high-voltage insulation and the power transformer is obviously small.