| The current power system has been formed to 220 kV voltage grade equipment as the backbone network,66 kV voltage classpower equipment for transmission network support. Only in Dalian Liaoning, there are sixteen 220 kV voltage grade substations, besides 66 kV voltage grade substations more than 70 blocks. In recent years, with the development of computer technology and power electronics technology, relay protection equipment and monitoring equipment used in various voltage levels of equipment are also constantly upgrading, and the original protection measurement and control device, due to aging equipment, low sensitivity, weak anti-interference ability and other reasons, will gradually be alternatived by new products and new equipment. Therefore, research and analysis of the content related to substation reconstruction project of transmission network systematicly, to deal with the questions that may be found in secondary system reconstruction project, is very necessary.This topic makes an appropriate design about secondary system, in view of the existing problems in the actual operation of the 220 kV substation, and carried out an analysis about the feasibility of the design. This paper mainly studies the following three problems:first, how to found and realize the breaker-failure protection in double transformation of busbar protection; second, a realization of backup automatic switch (short for BZT) when there are limited power lines "on the 66 kV busbar of a 220 kV substation; third, an improved method of remote control operation by the background machine in the 220 kV substation.This thesis work focuses on three point:the actionthe sequence programinng and the peripheral circuit design of BZT to make the BZT can automatically judge the running state of small power line and have the option to resection of it, the circuit design of a realization to failure protection dual configuration, the function of programed operation design, including the operation object design and logic design of station. The content of reconstruction design in this paper consistents with the actual operation requirements of substations, and has guiding significance for relay protection debugging and modification. |
