Voltage source converters

A spring arrangement for operating a high and medium voltage circuit breaker comprising:

• a main frame comprising a cylindrical housing having a main axis A,
• an actuation rod, a first end of which being coupled to a rotary shaft of the circuit breaker, a second end of the rod being movable in the cylindrical housing along the main axis A, a coil spring arranged in the cylindrical housing and coaxially to main axis A, wherein a first end of the spring is mounted on the claimed main frame and a second end of the spring is coupled with the second end of the rod, and
• a coupling arrangement coupling the second end of the spring with the second end of the rod,
• wherein the coupling arrangement comprises:
• an articulation for rotational guidance of the second end of the rod with respect to the second end of the spring around a second axis perpendicular to said main axis wherein the second end of the rod and second axis are located axially, along main axis A, at the second end of the spring,
• and wherein the coupling arrangement comprises sliding means for a translational guiding of the second end of the rod along said main axis, and
• at least one shaft coaxial to said second axis, that pivotally links the support plate to the second end of the rod.