New principle for feeder grounding fault protection based on zero sequence admittance is presented in this paper. Criterions for the line ground relay with zero sequence admittance are also discussed.

提出了采用测量线路零序导纳进行接地保护的新原理，讨论了直线式导纳继电器的接地保护判据。

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In April, China launched its first tracking data relay satellite to lessen its dependency on ground satellite control and relay stations.

CENTERFORSECURITYPOLICY: China��s one world?

But like radar technology, ADS-B currently relies on ground stations to relay information, making it useless over remote areas.

BBC: The key to preventing lost planes

Both spacecraft make use of the US space agency's Tracking and Data Relay Satellite System (TDRSS) to speak to the ground and controllers do not want any conflicts.

BBC: Total cargo: 4,860kg