Protection apparatus for a capacitor connected in series with an electric power circuit

A protecting apparatus for a capacitor connected in series with an electric power circuit for improvement of the power factor thereof comprising:

• a protecting gap assembly connected in parallel with the capacitor to bypass the capacitor current by discharging it in response to a predetermined excess voltage across the capacitor when an abnormall excess current flows through the capacitor,
• a bypass switch for short circuiting the gap assembly with the capacitor in response to the discharge current flowing through the gap assembly,
• the bypass switch being provided with a pair of contacts aligned with each other in faced relation to effect on-off operation,
• a fluid operational driving cylinder combined with one of the contacts of the bypass switch,
• an electromagnetic repulsion means combined with either one of the contacts for generating an electromagnetic repulsion force in response to the capacitor discharge current flowing through the protecting gap device to move one contact towards the other contact to make the contacts independent of the drivinng cylinder,
• the discharge gap device, the electromagnetic repulsion device and the pair of contacts being aligned along an axis so that the discharge gap device assumes the uppermost position,
• a concentric cylindrical member made of an electrically conductive material and mounted around the aligned parts,
• the cylindrical member having one closed end positioned at the side of the discharge gap device and one open end positioned at the side of the driving cylinder for the bypass switch,
• the cylindrical member being connected in parallel with the aligned parts to provide a current path including the gap device and a magnetic repulsion winding of the electromagnetic repulsion device for discharging the capacitor current until the capacitor bypass switch closes its contacts, and
• an enclosure filled with an electric insulating gas and enclosing the discharge device, the electromagnetic repulsion means and the gap bypass switch therein.