直流输电系统主要有2种运行方式：单极运行方式和双极运行方式。

There are 2 operation modes for DC transmission system:single pole operation and double-pole operation.

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直流输电系统主要有2种运行方式：单极运行方式和双极运行方式。

There are 2 operation modes for DC transmission system:single pole operation and double-pole operation.

youdao