In a cooling system for a variable vacuum capacitor, a liquid is arranged inside a cooling reservoir, a first part of the reservoir is designed to absorb heat energy from first bellows of the variable vacuum capacitor, the first bellows being responsible for transporting electrical energy to a second electrode of the variable vacuum capacitor, a second part of the reservoir is designed to dissipate heat energy towards a cooling circuit, and heat pipes are arranged between the first part of the reservoir and the second part of the reservoir.