Design Of Relay Protection For High Voltage Power Network

This design makes a relay configuration for HuangHua power supply company 220 kV high voltage power network,selecting some representative lines as configuration objects.Firstly,initial configuration has been made for every line according to “Technical code for relaying protection and security automatic equipment”.So the main protection is a combination of current comparison pilot protection and vertical linked distance protection,which is in accord with Relevant standards called “double redundancy arrangement”.On the other hand,the backup protection is three segment distance protection and four segment zero sequence current protection.Considering the practical operation of system,maximum and minimum operation mode are established for every protection of every line,laying the foundation for forming every sequence network figure.Secondly,with the help of software PSASP,it calculates the power flow and short circuit current.In this process,it firstly arrange awaiting calculation amount in power flow and short circuit table,reducing unnecessary calculate,which greatly increases efficiency.Thirdly,on the basis of short circuit results,it carefully collects all branching factor of every protection in every operation mode in every short pattern,therefore it finds maximum and minimum branching factors.Fourthly,it makes relay configuration for 10 protections in 5 lines in detail,then we check sensitivity of every protection.For some configuration that does not meet sensitivity,it analysis reasons and put forward some improved approaches.Finally,it gives out configuration list and CAD plan.