Communication requirements for control and monitoring of HV feeders in digital substation control system

Control, protection and monitoring sub-systems in HV and EHV substations have been changed considerably in the recent years. This is due to the usage of digital processing and communication technologies for implementation of these sub-systems. Using new digital control systems has led to addition of some new equipment and some changes in the function categorizing, functions allocation and data exchange philosophy in the system. In this paper some new concepts of function categorizing and communications in the new systems will be discussed. Results of a sample implementation of a control system will be described. Finally some important requirements of the system will be presented.