Abstract
China's power industry, as the country's most important energy industry, has been in the priority development status, Power for the development of enterprises is also eye-catching. Power system for the rapid development of protection have made new demands, which will enable the relay to rapid development.Protection is an anti-accident automational measure which is used to seek the countermeasure by means of studying the breakdown of power system, and the abnormal conditions which endanger operation safty. During its development,it is used relay to protect the power system and its components (generators, transformers, transmission lines, bus, etc.)in order to get it out of damage. So we call it protection. This design calculates the protection and adjustment of 220KV power grid .According to the characteristics and operation requests of the power grid, under the premise of protection requirement, which is "the liquid, the selectivity, sensitivity, reliability", we can find the best program for setting of operation mode, the short circuit current, the types of protection and the automatic reclosing.
