Study on Communication Service Strategy for Congestion Issue in Smart Substation Communication Network

Shared networks can improve the efficiency of smart substation communication infrastructure, but they pose challenges for the real-time performance and reliability of communication. By analyzing the traffic rate and causes of congestion in a substation environment, we propose a communication service strategy using a message information label to manage the congestion issues. This strategy implements fast identification and filtering of messages by condensing key information into a message label at intelligent electronic devices and checking it along with traffic rates at switches. We put forward a communication scheduling method called distributive length WRR_LLQ that adapts to the different characteristics and real-time demand of various message types. OPNET simulation results show that the strategy successfully identifies and discards disguised error messages with high traffic rates, avoids timeouts and packet drops in the transmission process of important messages when congestion occurs, and reduces the transmission time of other messages.