A power conversion system includes a converter circuit having switching devices, driver circuits to operate the switching devices according to switching control signal, and power supplies to power the driver circuits. The individual power supplies include a transformer with a primary winding and a secondary winding, a reference node coupled to a first terminal of the secondary winding, a power supply output node coupled to a supply input of an associated one of the driver circuits, a rectifier, including a first terminal coupled to a second terminal of the secondary winding, and a second terminal coupled to the power supply output node, and a clamp circuit, including a first terminal coupled to the first terminal of the rectifier, and a second terminal coupled to the reference node.