摘要：Abstract: Research and application progress of NARI-RELAYS in protection based on DPFC were reviewed, key technology employed in line, busbar, transformer and generator protection were presented. It was pointed out that integration of main and backup protection in one device and duplicate allocation was reasonable and beneficial. Key words: Protection; DPFC; Main protection; Backup protection; Duplicate protection
关键词：Research
0. Introduction
Electric power network in China has step into a new stage with large-scale networks, super power plants and high-rating generators. By the end of year 2002, total installed generation capacity is 353000MW, total length of 35kV and above transmission lines is 806500kM, total installed transformer capacity is 1194000MVA, and generated energy of the year is 164×1010kW·h。
As an important part of electric power system, protection is the technology measures to ensure the security and stability of power networks. Development of electric power system requires new functions and higher performance of protection. New progress in microelectronics, computer and communication technology makes it possible to improve protection further more.
NARI-RELAYS Electrics Co., Ltd. is the main base of research on protection principle and technology, and among the leading suppliers of protection and automation products in China. She has made great progress in research and application of new protection technology, especially series protection based on Deviation of Power Frequency Component (DPFC). She also possesses many invention patents. The author summarized these research and application progress, presented his own viewpoint on protection allocation, and look forward to discuss this issue with experts in protection area.