Circuit breaker and opening and closing method thereof

A circuit breaker, comprising:

• a vacuum valve;
• and
• quick opening means for driving an operating shaft of the vacuum valve toward an opening direction by electromagnetic repulsion, the breaker having
• an electromagnet comprised of a first coil, a second coil, a movable core and a permanent magnet and comprising an operating mechanism which excites the first coil to close the vacuum valve, holds the vacuum valve closed by an attractive force of the permanent magnet and excites the coil in a direction reverse to an excitation direction in closing operation to open the vacuum valve,
• wherein the electromagnetic repulsion coil for electromagnetic repulsion and the second coil are simultaneously excited in quick opening operation by electromagnetic repulsion.

A circuit breaker, comprising:

• a vacuum valve;
• and
• quick opening means for driving an operating shaft of the vacuum valve toward an opening direction by electromagnetic repulsion, with a first coil and a second coil coaxially disposed;
• the breaker having:
• an electromagnet comprising:
• a movable core which moves on a center shaft of the first coil and the second coil;
• fixed cores provided on upper, circumferential and lower surfaces of the first coil and the second coil;
• and
• a permanent magnet placed on the fixed core on the upper surface,
• the movable core comprising a circular plate with a face opposite to the fixed core on the upper surface and a plunger with a cylindrical face opposite to the first coil and second coil's inner circumferential surfaces;
• and
• an operating mechanism which excites the first coil to close the vacuum valve, holds the vacuum valve closed by an attractive force of the permanent magnet and excites the coil in a direction reverse to an excitation direction in closing operation to open the vacuum valve,
• wherein the electromagnetic repulsion coil for electromagnetic repulsion and the second coil are simultaneously excited in quick opening operation by electromagnetic repulsion.