Research and application on SDN to intelligent substation communication network

智能变电站在电力系统中处于重要地位，为了满足电力系统的要求，电力通信网结构不断地进行优化，大量引进通信领域新技术，使得电力通信网越来越复杂。影响变电站通信安全的因素日益增加，变电站通信网络安全这一问题变的日益复杂。本文以智能变电站的通信网络为基础，对智能变电站通信网络的发展历程进行简要介绍，分析比较几种通信技术的优缺点，针对变电站信息安全面对的威胁以及现阶段管理现状、管理制度等在实际运行中存在的问题进行深入讨论，全面研究分析了变电站面临的信息安全问题。 Intelligent Substation in the power system is an important factor. In order to meet the power system require- ments, the system constantly optimizes power communication network structures, including massive introduction of new communications technologies, making electric power communication network more complex than ever. Factors affecting the substation communication safety are increasing. Substation communication network security problems become more complex. In this paper, intelligent substation communication networks based on intelligent substation communication network development process are briefly described, and the advantages and disadvantages of several communication technologies are analyzed and compared . In the end of the article, this paper comprehensive analyzed substation informa- tion system threats, present management situation and management system in actual operation.

Tampering, forgery and theft of the measurement and control messages in a smart grid could cause one breakdown in the power system. However, no security measures are employed for communications in intelligent substations. Communication services in an intelligent substation have high demands for real-time performance, which must be considered when deploying security measures. This paper studies the security requirements of communication services in intelligent substations, analyzes the security capabilities and shortages of IEC 62351, and proposes a novel security scheme for intelligent substation communications. This security scheme covers internal and telecontrol communications, in which the real-time performance of each security measure is considered. In this scheme, certificateless public key cryptography (CLPKC) is used to avoid the latency of certificate exchange in certificate-based cryptosystem and the problem of key escrow in identity-based cryptosystem; the security measures of generic object-oriented substation event, sampled measure value and manufacturing message specification in IEC 62351 are improved to meet the real-time requirements of the messages as well as to provide new security features to resist repudiation and replay attacks; and the security at transport layer is modified to fit CLPKC, which implements mutual authentication by exchanging signatures. Furthermore, a deployment of CLPKC in an intelligent substation is presented. We also evaluate the security properties of the scheme and analyze the end-to-end delays of secured services by combining theoretical calculation and simulation in this paper. The results indicate that the proposed scheme meets the requirements of security and real-time performance of communications in intelligent substations.

The fast real-time application message is an object-oriented substation event—GOOSE (Generic Object Oriented Substation Event). It mainly works on the process layers and bay layers of digital substation. GOOSE intelligent substation communication network can realize the key function of the overall intelligent sub- station functions. This paper will make a systematic analysis of GOOSE. At first, it will provide a detailed analy- sis of the transmission mechanism and process of GOOSE message. As certain practical operability lacks the actual application of the multicast filtering method which is applied to GOOSE message based on IEC61850 standard, this paper will summarize three message filtering methods, compare the advantages and disadvantages in topological networks of different kinds in accordance with the instantaneity of GOOSE intelligent substation communication network and draw a conclusion that the independent configuration scheme of GOOSE and SV can adapt to the requirement of times, so as to provide theoretical references for the selection of practical intelli- gent substation communication network in the future.

Substation communication network (SCN) provides real-time, high-speed, and reliable data transmissions for the advanced monitoring and control functionalities, which are facing increasing cyberspace threats and attacks. Efficient threat perception and cyber situational awareness are essential to enhance secure and reliable SCN operations. This article explores multiscale SCN traffic pattern characteristics with holistic network traffic, separated network traffic for included devices (especially IoT devices) and separated network traffic of certain types of protocol. The proposed online traffic-oriented SCN traffic anomaly detection and cyber situational awareness models are designed for the network anomalies and cyber-attacks that could cause network traffic pattern variations. We leverage a fractional autoregressive integration moving average (FARIMA)-based dynamic threshold model to detect abnormal traffic patterns without sophisticated computations or deep packet inspection. The SCN real-time operation conditions are timely quantified through the statistical methods with the alliance of SCN topology and protocols. The cyber situational awareness model is further carried out to evaluate the most affected protocol and security risks of various devices in SCN using Grubbs’ test. The experiment results are carried out based on a real 110-kV intelligent power substation. The numerical results confirm the comparative low mean square error (MSE) and low complexity of the online traffic characterization when forecasting holistic network traffic and separated network traffics. Furthermore, the timely and quantified cybersecurity risk analysis is conducted based on the SCN traffic with varying scales to detect cyberspace threats and identify the high-risk SCN devices and the most affected protocol.

This paper puts forward a security audit scheme that combines SCD configuration file parsing with network traffic identification. Obtain a pre-defined network topology and virtual link logic loop by parsing the SCD file and establish a security baseline for the service. Identify and capture generic object-oriented substation event (GOOSE) messages, sampled value (SV) messages, manufacturing message specification (MMS) messages, and the information of devices connected to the switch to obtain the actual network topology, and virtual link physical loop. When an unknown system IP, communication protocol, or message occurs, the device protocol auditing alarm can be triggered. And when the device polling data traffic is missing, the offline disconnection alarm of the auditing device can be triggered. The manipulation of industrial control command parameters caused by Trojans, computer viruses, and man-in-the-middle attack, and the abnormal state caused by operators’ misoperation also can trigger the legal abnormal alarm. In this way, real-time monitoring and security auditing of intelligent substation network threats can be realized.

A neural network-based traffic routing algorithm, to be implemented in an intelligent computer communication network, is presented. It simultaneously takes into account the shortest path and channel capacity and determines the necessary connections and weights of the neural network, thus providing an optimum transmission path from source node to destination node. The algorithm is based on the Hopfield type of neural network approach, and can be considered as a massively parallel distributed processing system with the ability to improve performance through dynamic learning. The power of neural network algorithms to solve routing problems and provide dynamic response to traffic conditions measured throughout the network system is investigated. No congestion occurs in this network because of the changes in the statistics of the input traffic load. A computer simulation result for a 10-node network shows the efficiency of using the neural network-based algorithm. >

At present, to precisely ensure the routine use of intelligent vehicles' communication network, accurate data transmission is of great importance, which can also, to some extent, improve the network failure management and maintenance of smart cars, thus affecting the intellectual analysis ability of intelligent cars. Therefore, it is very necessary to perform real-time monitoring of abnormal data in the everyday use of smart cars and their regular operation. Based on the detection of anomalous data of intelligent vehicles, an instantaneous frequency estimation method of signals transmitted by a communication network is proposed in this paper. In terms of abnormal data detection, after the time-frequency decomposition of the output signal of the collected communication network, the collected anomalous data can be detected by extraction, and then the detected and captured abnormal data is filtered to finally complete the characteristic extraction of the strange frequency of the abnormal data.

The concept of Smart Grid enforces standard power grid with intelligent devices and communication network to add new functionality to the power distribution system. The concept builds upon enormous volumes of metering and monitoring data, and thus also a robust communication infrastructure. Apart from pilot projects, modeling and simulation plays an important role in smart grids design, since it provides an opportunity to effectively benchmark and compare particular technologies, especially for its communication infrastructure.

The establishments of intelligence substations are smart power grid development trend. So how to share the models and graphics in intelligent substations with master station to reduce power operators' duplicate work is a problem worth studying. After the analysis of the IEC61850 and IEC61970, a method is presented in this paper to solve that problem. Based on substation modeling following IEC61850 and master substation modeling following IEC61970, substation model can be transferred to master station by files and converted into relative format for master station to use. On the other hand, substation relative graphics with model information can also be transferred and reused in master station. By using this common model transformation method, the data and graphics are interoperable in kinds of power automation systems. It is helpful to lay the foundation of a unified platform.

Currently, much awareness is paid to the effects of smart grids on efficiency of power systems and energy districts, and the selection of suitable operating modes for equipment for transmitting electric energy. Modern intelligent networks have an impact on ensuring a stable state of power system operation modes, increasing their reliability in operation, and increasing the quality of electric energy. The article analyzes the use of intelligent electrical networks and intelligent network systems in both Western countries and the Russian Federation. Statistical data on electricity consumption and forecast values for this rate of consumption are given. In the future, until 2020-2025, there will be a gradual transition to a new type of electric grid organization - smart grids. The use of electric power systems in conjunction with innovative digital information management systems will significantly change the technical and economic characteristics of future power systems in a positive way. The comparison of technical parameters of traditional and intelligent electric networks, as well as the classification of the main groups of devices controlled (flexible) by AC power transmission systems is carried out. Systems are divided according to the principle of power regulation. Implemented projects of using flexible alternative current transmission system devices in the world are presented. As a result of the analysis, it was found that China is actively developing managed (flexible) AC power transmission systems, with a large amount of investment from the state, the volume of investment is much larger and amounts to about $ 70 billion per year.

The challenges posed by the future wireless communication network, which will be a huge system with more complex structures, diverse functions, and massive communication ends, will be addressed by intelligent wireless communication technologies. These technologies are playing an increasingly important role in network architecture, computing architecture, resource allocation algorithm design, etc., thanks to the rapid development of artificial intelligence technologies, particularly the deep learning technologies, and their extensive application in various domains. In this paper, an endogenous intelligent architecture is developed to effectively clarify and understand in-depth the relationship among the factors by constructing wireless knowledge graph for the air interface transmission, the core network, as well as the network environment, and so on. Furthermore, the knowledge graph simultaneously reveals the structure and operation mechanism of the whole wireless communication networks. Cause tracing, intelligent optimization, and performance evaluation are sequentially implemented based on the knowledge graph, thus forming a complete closed-loop for endogenous intelligent wireless communication networks.

The NARI Grid Power Research Institute proposed an ontology for substation management – NARI Ontology (NARIO). The key function of a smart power grid replies on intelligent autonomic substation management, however, current substation management system lacks global orchestration, and the topology analysis methodologies used are domain specific and expensive both in time and storage. This paper proposes a formal ontology for the autonomic substations management in smart power grids, NARIO, by leveraging the existing industry ontologies and best practices. We view the resource of substations in a smart grid from three perspectives, namely, Device, Wire, and Interval. An prototype system implementing NARIO for autonomic substation management is developed in Python, with the rules written in hybrid SPARQL and Prolog. It has been evaluated in a real-life substation in Anhui, China. From the evaluation results presented, it is evident that the proposed NARIO can provide feasible and efficient topology analysis, orchestrating over the entire smart grid, with average query execution time over- head as low as around 0.05 seconds.

Techniques and features that have been found useful for modeling and simulating intelligent multimedia communications networks are described. Key ingredients are a robust, commercially available and supported simulation language and a modeling and simulation architecture that consists of custom-designed modules of the features that clearly occur in communication network simulation. The simulation architecture used is described at length. >

Electronic current transformer (ECT) is widely used in smart grid, especially intelligent substation. However, fault is unavoidable for ECT in long term operation. In this paper, the fault of an 110kV independent ECT based on low-power current transformer is an example to analyze the reasons for the fault via reasonable analyzing methods and proposed the corresponding treatments.

With the development of smart grid and global energy internet, new information and communication technologies such as big data, cloud computing, Internet of Things and broadband wireless have become the key core technologies of smart grid. As a key node in smart grid, the security of smart substation has a direct impact on the overall security of power system. This paper by analyzing the potential safety hazards that intelligent substations are vulnerable to at present, and enumerates the safety protection technologies applied nowadays, based on the fact that the station control layer of the intelligent substation security protection system is not directly monitored, this paper discusses the application of network security technology in the internal network monitoring of the station control layer of the intelligent substation, and puts forward the concrete scheme.