Energy supply device and converter valve

The invention provides an energy supply device and a converter valve. The energy supply device comprises a damping circuit, a rectification circuit, a voltage amplitude limiting unit, a first diode, a first capacitor, a DC-DC isolation unit and a second capacitor, wherein one end of the damping circuit is connected with a first output end of the rectification circuit; the voltage amplitude limiting unit is connected in parallel with the rectifying circuit; the anode of the first diode is connected with the first output end of the rectifying circuit, the cathode of the first diode is connected with one end of the first capacitor, and the other end of the first capacitor is connected with the second output end of the rectifying circuit; the direct-direct isolation unit is connected in parallel with the first capacitor; the second capacitor is connected in parallel with the output end of the DC-DC isolation unit; the output end of the second capacitor serves as the positive output end and the negative output end