Patent ID: 7336461

Claim:
Method for determining a reclose time of a circuit breaker ( 6 ) on an electric network, said network comprising: a high voltage source (S), a thre-phase transmission line (L), a circuit breaker ( 6 ) comprising at least three pairs of contacts ( 7 A, 8 A ; 7 B, 8 B; 7 C, 8 C), each pair being associated with one of the three phases (A, B C) of said line (L) and allowing an interruption of a current circulating between said source (S) and said line (L) by separating said contacts in the event of a fault on the associated phase, the first contact being on the source side and the second contact being on the line side, a shunt compensation reactor ( 5 ) to compensate capacitive reactive power of said line (L), said reclose time being determined in the event of separation of the contacts of each pair of contacts in the presence of a fault on one of the three phases, said determination of said reclose time being made using the following steps: measuring a voltage (UL A0 ,UL B0 , UL C0 ) between the line side contact and ground for each of the phases, measuring the a voltage (US A0 ) between the source side contact and ground for at least one phase, determining a voltage (US A0 , US B0 , US C0 ) between the source side contact and ground for each of the phases, said determination of said reclose time being characterized in that it also comprises the following steps: calculating, for two separate phases called first and second phases, the voltage difference (UL AB , UL AC , UL BC ) between the line side contact and ground for said first phase, and the voltage difference between the line side contact and ground for said second phase, the calculation being made for each pair of separate phases, calculating the voltage difference (US AB , US AC , US BC ) between the source side contact and ground for said first phase, and the voltage difference between the source side contact and ground for said second phase, the calculation being made for each pair of separate phases, determining said reclose time on the basis of said voltage differences.