| 摘要 |
PURPOSE:To stop only the side of one pole easily by a method wherein the poles on one side of a DC circuit for a bipolar DC transmission system are provided with current intercepting means respectively. CONSTITUTION:During DC bipolar operation, converters 3, 3', 6, 6', consisting of a multitude of series and parallel connections of thyristors and the like, are controlled through AC bus bars 1, 1' and transformers 2, 2', 5, 5' to convert AC-DC and DC-AC and make DC current 11, 12 flow through DC transmission lines 4, 7 while a difference between the DCs 11, 12 flows through metallic bus bars. When a current on one side of a polar line or the converters 3, 3' is desired to nullize, the converter 3 is gate-blocked and a counter electromotive force is generated by the converter 3' into a direction cancelling a divided DC current I2' as a reverse converting operator 3 as shown by an arrow 11 in the drawing. When the electromotive force becomes larger than a voltage, generated by the returning current of the operating pole, which flows through the metallic line 8, the divided current I2' becomes zero. According to this method, the operation of the other pole may be stopped while operating one pole as it is. |
