| 摘要 |
PURPOSE:To reduce facility cost of lower substation by preventing reverse power flow due to the unbalance of load of double bus upon opening of bus circuit breaker without providing a reverse power re lay. CONSTITUTION:A power system wherein power is received at a lower substation 20 through double transmission lines 7, 8 from an upper substation 1 with a bus circuit breaker 25 being connected between buses B1, B2 is provided with a reverse power flow notifying contact 4a which closes when the current flowing through the bus circuit breaker 2S exceeds a set value determined by the capacity of transmission line, circuit breakers 2R, 5R, 6R located at the power receiving terminals of respective transmission lines and close at the time of double line power receiving, and means for disabling opening of the bus circuit breaker 2S on conditions that the reverse power flow notifying contact 4a and the circuit breakers 2R, 5R, 6R are closed. |
