English Title Of Master Dissertation

Relay protection device is one of the important devices that guarantee the stable circulation of power system. In recent years, with the development of transformer substation's integrated automatization, and its popularization, it is demanded in the power department of all countries that the protection device controlled by the computer that has the function of protection, measure, control and communication should be researched and developed.At first the thesis introduces briefly the theory of 35KV circuitry protection device, analyzes the low- voltage circuitry protection device and expounds the protection principium and adopted relay protection algorithm. Then, the thesis expatiates the software in modules. To be specific, the thesis expatiates the main program, data processing and reckon judgment.Communication is one of the important features. After introducing briefly the popularly-used in relay protection device of 103 communications agreement, the thesis explains how 103 communications agreement works in the device. The device can communicate with surveillant devices and during the communication process, write down the time and type of malfunction so that the loss of electricity can not affect it.