摘要 |
<p>1,124,521. Converting. ALLMANNA SVENSKA ELEKTRISKA A.B. 7 Jan., 1966 [9 Jan., 1965], No. 770/66. Heading H2F. A high voltage direct current power transmission system has two separate transmission lines 6, 7 and at least four converter stations 4, 5, 8, 9. Normally, each line connects two stations, and the two lines are not interconnected. If a fault occurs on one line the converters associated with that line are automatically blocked, reconnected to the other line and restarted. Before restarting, the voltage regulator of the first transferred station to be restarted is adjusted so that the no-load voltage of the station is less than the line voltage. Consequently the fault-free line is unaffected by the connection of this station. If the first transferred station to be restarted is an inverter, its current regulator is also adjusted so that it draws either zero current or a current less than the current margin in the fault-free line. The second transferred station may then be restarted without any adjustment of its regulators.</p> |