3 PHASE HIGH-SPEED CURRENT LIMITING CIRCUIT BREAKER AND COORDINATED SYSTEM OF ELECTRIC POWER SYSTEM

PROBLEM TO BE SOLVED: To provide a current limiting type 3 phase alternate current electrical switchgear that is a 3 phase high-speed current limiting circuit breaker which cuts off the accident current at high speed without waiting for its zero point when the large current accident occurs in a load side. SOLUTION: It consists of a high frequency current generating circuit, which makes the current of frequency higher than the frequency of a 3 phase alternate current circuit superimpose on the breaker parts 7 respectively, and a 2nd drive part 61, which is controlled by the control part 80, and makes the high frequency current generating circuit start with the electromagnetic repellent according to the 2nd electromagnetic coils 100 respectively. When an accident occurs, the control part 80 makes the 2nd drive part 61 drive, makes the high frequency current from the high frequency current generating circuit superimpose on the breaker parts 7, and makes the zero point form in the current which flows in the breaker parts 7 to make the breaker parts 7 open.