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- Power system for the rapid development of protection have made new demands， which will enable the relay to rapid Three-phase current protection relay is one of the important forms of Based on a detailed study of three lines of defense to protect the various components and wiring， Setting calculated in accordance with the principle of derivation of the three-segment protection movements value sensitivity and duration tuning and the use of mathematical tools for MATLAB software programming， Simulation of a 35 kV single-ended power supply network syllogism current protection of the setting， Finally， the software MATLAB Simulink simulation waveform The simulation results show that the study syllogism current protection is an ideal line It can help protect all of the interaction so that the protective properties of the Keywords : protection; Three-phase current protection; Setting; MATLAB Simulink
