No abstract

The construction of power Internet of things is an important development direction for power grid enterprises. Although power Internet of things is a kind of network, it is denser than the ordinary Internet of things points and more complex equipment types, so it has higher requirements for network security protection. At the same time, due to the special information perception and transmission mode in the Internet of things, the information transmitted in the network is easy to be stolen and resold, and traditional security measures can no longer meet the security protection requirements of the new Internet of things devices. To solve the privacy leakage and security attack caused by the illegal intrusion in the network, this paper proposes to construct a device portrait for terminal devices in the power Internet of things and detect abnormal traffic in the network based on device portrait. By collecting traffic data in the network environment, various network traffic characteristics are extracted, and abnormal traffic is analyzed and identified by the machine learning algorithm. By collecting the traffic data in the network environment, the features are extracted from the physical layer, network layer, and application layer of the message, and the device portrait is generated by a machine learning algorithm. According to the established attack mode, the corresponding traffic characteristics are analyzed, and the detection of abnormal traffic is achieved by comparing the attack traffic characteristics with the device portrait. The experimental results show that the accuracy of this method is more than 90%.

In power Internet of Things environment, the existing border-based protection system and the “one-time authentication, one-time authorization, and long-term effective” approach are difficult to deal with the threat of attacks from internal and external devices and users with legal authority. In order to solve the problem of authorized access of power equipment and users, combined with behavior risk assessment, a continuous trust evaluation scheme of power equipment and users is presented in this paper. The scheme is evaluated by the combination of direct trust, indirect trust, and comprehensive trust and adds the penalty reward factor and time attenuation function to improve the reliability of the results. In addition, this paper will quantify the risk of the behavior of power equipment and users and regard it as a factor affecting the degree of trust, so as to achieve continuous trust evaluation of equipment and users.

No abstract

This paper analyzes characteristics of the wide area protect communication system structure, and divides communication systems into the system protection center, backbone network, and regional communications systems. And regional communication system is divided into regional protection centers, regional networks and sub-station system. Then This paper analyzes the reliability of the fiber optic ring network which is used widely, and establishes the reliability model of each subsystem. As IEEEl4 bus for example, we calculate the reliability of each subsystems and overall system, then we get the sub-station is a bottleneck affecting the reliability of the entire communication system. But in wide area network, ATM switches are weakest link components. We use Bayesian network as reliability evaluation method. The reliability evaluation method of Bayesian network not only can be easily used to calculate the reliability, but also can find the thin section of system by its unique reverse reasoning technique. High-reliability Wide-area protection communication system is an important part of wide area protection system for its correct and reliable operation.A is the availability of the optical fiber between the ATM switch and the server. Similarly, we can get the reliability model of the system protection center and availability. B. reliability model for LAN and backbone networkWide area protection communication system is divided into two Layers network which consisted of the LAN and the backbone network. This network structure can not only realize free communication between the system protection and the regional protection centers and sub-station and the regional protection of communication, but also it can limit area protection communication system to the local scope to avoid the congestion of the backbone. LAN can be star or ring network, and the backbone network communication network uses the structure of the ring network. Now the backbone of communication network in Power system uses SDH ring network as the main network. For example the backbone communications network in Southern Power Grid is a typical ring network structure [9]. The common mode of SDH ring network is two-fiber unidirectional path ring, two-fiber unidirectional multiplex section-channel ring or four-fiber bidirectional multiplex section-channel ring network [10]. In this article, we use the two-fiber unidirectional path ring for reliability analysis and reliability model. 0.8291 3271 0.9997 2079Considering the reliability of the sub-station have great impact on the reliability of the entire wide area protection communication system. Assuming availability of sub-station communication system is 1, and the wide area protection communication system corresponds to the wide area communication system, the availability of the communication system such as shown in table 3.