智能变电站通信网络及其安全问题分析

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.

Intelligent substation is an important part of building a strong and smart grid, which is the key “anchor” of six aspects of information exchange of smart grid. However, there are still some issues in the current construction of intelligent substation. To further improve the construction of intelligent substation, improve intensive network management, improve network scalability, this paper proposes applying OpenFlow-based SDN technology to the intelligent substation communication network, simulate the network environment and test the performance.

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.

Smart grid can work effectively only when a reliable, fast communication network is available. The communication network is a prerequisite to connect different protection, control, and monitoring equipment within the substation. Ethernet fulfills all the requisites such as reliable, fast, secure, interoperable, LAN-based communication system for smart substations. Therefore, the main aspect is to improve the reliability of the network by prioritizing the critical components by using the knowledge of component importance measures (CIM). In this chapter, analysis of IEC 61850 ethernet-based substation communication network (SCN) architectures has been examined using various reliability importance measures (RIM). The importance measures namely Birnbaum, improvement potential, criticality importance, and reliability achievement worth have given their justified rankings of the various components of SCN architectures. The practice of these CIMs works towards the identification of the components that can be allocation of resources for the improvement of system reliability.

In the last decades there have been great advances in electronic, information and communication technologies. Up to date, any of these advances have been implemented in electrical systems, but some difficulties have been encountered, particularly regarding to the integration of intelligent electronic devices from different manufactures into a centralized system. With the aim of solving the above mentioned problem, the standard IEO 61850 was developed to specify communication networks in substations. In addition to control and protection functions, the information model created around IEO 61850 series can help the development of other applications related with electrical monitoring systems. Monitoring can be used to achieve a variety of benefits for utilities, including maintenance prediction, failure prevention, active control, improved commissioning tests and more accurate end of life assessments. Examples of application that could be highly benefited by the adoption of IEC 61850 as standard for communications in the power electrical industry are power quality monitoring and condition based maintenance.In this paper, the new standard IEC61850 and the new opportunities that it can offer to the electrical industry are presented. Firstly, a brief presentation of IEC61850 and the main benefits it provides are described. Finally, a more detailed description of the possibilities that IEC61850 can offer in the field of power quality monitoring and condition based maintenance (CBM) is highlighted.

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.

Power systems and especially Smart Grids increasingly apply Information and Communication Technologies (ICT) for exchanging information over wide area networks. Here, the performance of the ICT has become crucial for the development of new Wide Area Monitoring, Protection And Control (WAMPAC) [1] systems. In this context, simulations are a common way for evaluation, but power systems and communication networks are usually analysed with dedicated simulators. Therefore a combined simulation for analysing the dynamics and mutual impacts of both domains is needed. In this paper we present a generic hybrid simulation architecture based on the IEEE standard 1516 - High Level Architecture [2] to enable a combined simulation of power systems and communication networks in an integrated simulation environment. First, we introduce our hybrid simulator architecture, along with the communication and synchronization process between sub-simulators. Secondly, we present our communication networks architecture for modelling the network traffic caused by the information transmitted by control and protection algorithms within the electrical transmission system. Finally, we introduce our modelling approach for mapping entities between the power systems and the communication networks. For this purpose, we introduce our concept of a Substation Data Processing Unit, which represents entities on substation level by providing an IEC 61850 [3] based model for mapping logical functions for local process control, implementing decentralized protection and control algorithms and providing additional components for the power systems (e.g Phasor Measurement Units (PMUs) [4]).

The path congestion and communication risks of electric power communication network have emerged as the carried businesses are becoming more and more heavy. In this paper, a multi-objective optimization method for power communication network routing considering the importance of the carried businesses is proposed to reduce load imbalance and transmission risk. Firstly, information entropy is introduced as the objective of communication network load balancing optimization. And a risk assessment model for power communication network nodes and links is established. Then fuzzy membership functions are adopted to singularize the two objectives to jointly optimize path congestion and communication risks. The device nodes are dynamically divided according to the carried businesses to pursue the global optimization of the power communication network in which the Yen's algorithm is adopted. Finally, this paper uses the IEEE 30-bus communication network to carry out case simulations and analyzes the proposed method to verify the effectiveness and feasibility.

Electrical substation is one of the most important parts of power system network. Over the years, the substations have undergone several structural and technical modifications. The IEC 61850 standard launched by the International Electrotechnical Commission (IEC) has created a strong platform for modern Substation Automation Systems (SAS) based on Digital Communication Systems. To increase the system reliability and efficiency, the Substation Communication Network (SCN) should have a quicker response, especially during electrical faults. According to the IEC 61850 standard, the end-to-end (ETE) time delay for transmission and control of data has to be less than 4-ms which is achievable when the data packet size is smaller. However, when the packet size is larger, it exceeds the delay time limit. Hence, sending smaller data packets could be a solution, but sending too many smaller packets might create congestion in network incurring another delay issue. This paper presents a different network topology that is designed in Optimized Network Engineering Tools (OPNET) environment which is capable of transmitting and controlling larger data packets within the 4-ms time delay limit as recommended by the IEC 61850 standard.

Collaborative optimization of distribution network and 5G base stations considering its communication load migration and energy storage dynamic backup flexibility

Power system security and stability control is heavily dependent on the reliability of communication network. The communication interruption and latency may cause security and stability issues in power system. Thus, studying the dynamic procedure of the interaction between power system and communication network in fault situation becomes more and more important. In this paper, by analyzing the weakness of the existing co-simulation frameworks, a new co-simulation framework, Global Status Event-Based Iterative Co-simulation Framework, is proposed, in which a global event scheduler manages the communication simulator and power simulator, and power simulator will run iterative simulation as a new event is identified and added to the global event scheduler. Then, a co-simulation platform based on the proposed framework is introduced which integrates the power system simulator and communication network simulator. Finally, a case is studied and reveals the procedure of the cascading failures in both power system and communication network, which cannot be captured by the simulation of a single system.

The smart grid has evolved into cyber-physical power system (CPPS) with the integration of information and communication technologies (ICTs). CPPS can be treated as a typical hierarchical control system (HCS) which can be divided into two parts: power grid and communication network, and four layers: physical layer, secondary device layer, zone control layer and control layer. Compared with traditional power systems, CPPS will face new contingencies, especially from communication networks which can cause cascading consequences. To address this challenge, a vulnerability assessment using double power flow method is proposed in this paper. In addition, a whole CPPS model including four layers is presented. The model is based on the IEEE 39-bus network using MATLAB and MATPOWER toolbox. The model contains double power flows, one is to simulate the virtual power flow driven by the decision from the control centre and second one is to simulate the actual power flow. During a cyber-attack, the results from the double power flow method demonstrate a difference which serves as an indicator that a cyber-attack has occurred. The proposed novel vulnerability assessment index considers cyber latency, voltage variation and node centrality as three key parameters in comparing the importance of different nodes. The results can quantify the vulnerabilities in cyber nodes and assess the impact for cyber security strategy.

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.

Welcome to the Second International Workshop on Intelligent Communication Networks (IntelNet 2011), which is being held in conjunction with the 10th IEEE International Conference on Ubiqutious Computing and Communications (IUCC 2011) on August 24-26, 2011, in Dalian, China. Modern communication networks have been becoming more and more large-scaled and complicated due to rapid development and interconnection among heterogeneous communication networks. Therefore, the management and maintenance of modern communication networks have posed many grand challenges to both industrial and academic communication communities. To overcome these challenges, it is very necessary to find new levels of autonomy and intelligence in designing, deploying, managing, and maintaining communication networks. This workshop aims to bring together scientists, researchers, professionals, and practitioners from both industry and academia to exchange ideas, discuss solutions, share experiences, and report state-of-the-art research results on various aspects of intelligent communication networks. In response to the Call-for-Papers of IntelNet 2011, twelve submissions were received from different countries. All submissions were reviewed by at least two referees from the technical program committee to ensure that papers published by IntelNet 2011 are of high quality. The submissions were then ranked according to their original contribution, technical strength, presentation, and relevance to the theme of the workshop. Finally, six papers were selected for presentation at the workshop and inclusion in the proceedings of IUCC 2011. We highly appreciate the IUCC Workshop Organizing Committee for giving us this opportunity to organize IntelNet 2011. We are very grateful to the Steering Committee for their valuable advice and continued support. We would also like to thank the authors for their great contributions and all Program Committee members for providing timely and in-depth reviews. Finally, we thank the attendees of this workshop and hope you will enjoy the program.