Liquid arc extinguish chamber for direct current breaking, direct current breaker and method thereof

A direct current breaker, consisting of two branches in parallel:

• a first branch comprising:
• a liquid arc extinguish chamber for direct current breaking, comprising:
• a cavity, in which a liquid medium is sealed, wherein the liquid medium comprises plant oil or transformer oil and the cavity is fully filled with the liquid medium;
• a fixed contact made of pure copper, a copper-tungsten alloy or a copper-chromium alloy, hermetically fixed in the cavity and sealed in the cavity in a bellows seal manner, wherein one end of the fixed contact is fixed in the cavity, and the other end of the fixed contact is connected with an outlet terminal A1;
• and
• a moving contact, movably sealed in the cavity in a bellows, slidable seal manner, wherein one end of the moving contact adjacently abuts against or is in contact with the fixed contact, and the other end of the moving contact is connected with an outlet terminal A2;
• and
• a second branch consisting of an energy dissipation device, connected in parallel with the liquid arc extinguish chamber, wherein one end of the energy dissipation device is mechanically and electrically connected with an outlet terminal A1, and the other end of the energy dissipation device is mechanically and electrically connected with the outlet terminal A2,
• wherein when the moving and fixed contacts are closed, a current I1 flows through the moving contact and the fixed contact and no current flows through the second branch;
• when the moving contact is pulled open for breaking, an arc generated between the moving contact and the fixed contact vaporizes the liquid medium to form a liquid j et;
• and the liquid jet pushes the arc to move so as to raise an arc voltage, and the arc voltage triggers the energy dissipation device to be conducted to allow a current I2 to be quickly transferred and be cut off by the energy dissipation device and no current flows through the first branch, thereby completing current breaking;
• wherein when the moving contact is in contact with the fixed contact, the current I between the terminal A1 and the terminal A2 is equal to the current I1 of the fixed contact and the moving contact and no current flows through the second branch;
• and when the moving contact moves away from the fixed contact, the current I is equal to a current I2 of the energy dissipation device and no current flows through the first branch;
• wherein the moving contact comprises an outer portion and an inner portion, the inner portion is disposed within the cavity, the outer portion is disposed outside of the cavity, the outer portion is directly connected with one end of a pull rod through a fixed joint;
• the pull rod is configured to be rotatable along the fixed joint and to drive the moving contact to the fixed joint;
• the pull rod is substantially perpendicular to the moving contact;
• and when the pull rod rotates in a clockwise direction against a pivot, the moving contact moves away from the fixed contact horizontally and when the pull rod rotates in an anticlockwise direction against the pivot, the moving contact moves close to the fixed contact horizontally, wherein the pivot is adjacent to the pull rod;
• and
• the other end of the pull rod is connected with one end of a driving device;
• the other end of the driving device is connected with a retaining device;
• the driving device is an electromagnetic repulsion-based driving device;
• and the retaining device is a bistable spring retaining device.