The development of the line protection device intelligence provides a hardware and software platform for the adaptive-setting and optimization of performance of the protection device. The scheme of self-setting for each protection device is proposed to achieve setting placed in front for users

adaptive setting placed behind and listing of self-setting principle. In order to improve the performance of distance protection

reverse distance protection and full-length segment are added

the acceleration method of segment Ⅱ of distance protection is improved

and function of line length is suggested to self-adapt to setting distance Ⅰ and Ⅱ. Based on the voltage phasor method of high-resistance grounded distance components

zero-sequence inverse-time over-current protection is optimized to speed up and improve the selectivity of protection. The simulation results of numerical example show the validity of the proposed method.