Analytical Modeling of Traffic Flow in the Substation Communication Network

Abstract

A custom designed and well monitored substation communication network (SCN) can maintain the fast and reliable information transmission and lead to improved operation and management of a substation automation system (SAS). In order to achieve this goal, a traffic flow model, including a port connection model, a traffic flow source model and a traffic flow service model of a SCN is developed in this paper. Based on the traffic flow model, a traffic flow calculation algorithm is designed to obtain the distribution of traffic load and maximum message delay. In order to verify the accuracy of the proposed method, the SCN of a simplified substation is established in the laboratory. And the distribution of traffic load and maximum message delay calculated using the proposed method is compared to that measured by a network analyzer. Further more, possible applications, such as network device selection, network performance analysis and sensitivity analysis, of the proposed method are demonstrated based on a typical 220 kV substation.Index Terms-substation automation system (SAS), traffic flow analytical model, IEC 61850, traffic load distribution, maximum message delay distribution.

Modeling of IEC 61850 GOOSE Substation Communication Traffic Using ARMA Model

“…This model will further be complexified in the sense of including modeling of the interaction between the electrical and communication grid, for analysis and control of smart grids as cyber-physical systems. A comparison of the proposed model with a model in [11], based on the queueing theory, which allows the message distribution delay being estimated, is in progress.…”

Supporting Sustainable Maintenance of Substations under Cyber-Threats: An Evaluation Method of Cybersecurity Risk for Power CPS

“…A port connection model of the communication network in a substation was established by basic matrix expressions and operations in graph theory. It also considered the communication technologies widely used in SAS, e.g., virtual local-area networks (VLANs) and transmission control protocol (TCP) [34]. The mapping from the port connection model to the modified hypergraph model of the SAS is relatively easy to achieve, since the properties of devices are known by the operators of a substation.…”

“…where sup{S} means the least upper bound and inf{S} means the greatest lower bound of subset S [34]. Then, the equivalent velocity of data flow past a physical node that is an element in V can be determined by the equivalent bandwidth b d (•) corresponding to the node's service curve.…”

“…All the sources are regarded as periodic packets, and the traffic of message injection can be determined by the length of the source message. The length and priority of different message types are set up ahead of time [34]. If the ultimate target of the cyberattack is IHMI, the MMS message is sent from the station PC to the IEDs at the bay level (e.g., the protection IED, PDIS), and its priority is 4.…”

“…Therefore, if the target is PDIS or XCBR, a delay of no less than 52 ms or 2425 ms is required, respectively, by a jamming attack to affect the normal operation of the whole The cumulative delay on different paths can be increased by inserting messages with higher priority in the queuing sequence, such as the GOOSE message with a priority of 7, which is the highest priority in SAS, or the SV message with a priority of 6. The GOOSE messages of the substation occur in a burst period with an interval of 0.002 s, and the maximum processing time for two IEDs is 2.4 ms [34]. Then, the maximum network delay of tripping GOOSE messages should be less than 0.6 ms and the maximum network delay of GOOSE messages apart from tripping GOOSE should be less than 7.6 ms.…”