Driving system for an on-load tap changer

An on-load tap changer, comprising a driving system comprising:

• a vacuum interrupter driving mechanism configured to drive a vacuum interrupter of the on-load tap changer;
• an energy accumulation mechanism mechanically coupled with the vacuum interrupter driving mechanism;
• and
• a flywheel mechanism mechanically coupled with the vacuum interrupter driving mechanism, wherein the flywheel mechanism comprises a flywheel which is configured as an annular rounded flywheel, such that there is a free space inside the annulus of the annular rounded flywheel when coupled to the vacuum interrupter driving mechanism,
• wherein the energy accumulation mechanism is mechanically coupled with a primary driving unit and the energy accumulation mechanism is configured to accumulate and release energy for combined motion of the vacuum interrupter driving mechanism and the flywheel mechanism, and
• wherein the vacuum interrupter driving mechanism and the flywheel mechanism are arranged along a main driving axis and the flywheel is concentrically arranged around the main driving axis.

A method of operating a driving system for an on-load tap changer, the method comprising:

• mechanically coupling an energy accumulation mechanism of the driving system with a primary driving unit of the driving system to accumulate energy;
• mechanically coupling the energy accumulation mechanism with a vacuum interrupter driving mechanism of the driving system;
• mechanically coupling the vacuum interrupter driving mechanism with a flywheel mechanism, wherein the flywheel mechanism comprises a flywheel which is configured as an annular rounded flywheel, such that there is a free space inside the annulus of the annular rounded flywheel when coupled to the vacuum interrupter driving mechanism, and wherein the vacuum interrupter driving mechanism and the flywheel mechanism are arranged along a main driving axis and the flywheel is concentrically arranged around the main driving axis;
• accumulating energy in the energy accumulation mechanism by loading the energy accumulation mechanism through operation of the primary driving unit;
• and
• releasing the accumulated energy from the energy accumulation mechanism for combined motion of the vacuum interrupter driving mechanism and the flywheel mechanism to drive a vacuum interrupter of the on-load tap changer.