Substation Network Research Articles

Congestion control method for overloaded service of smart substation under high concurrent users

Overload service in the communication network of smart substation will cause congestion, resulting in low overload service throughput, high congestion rate and long congestion control time in the average smart substation. A congestion control method for overloaded services in smart substations with high concurrent users is proposed. According to the characteristics of overload service request of smart substation, the mathematical model of the algorithm is defined by describing the overload service request of smart substation on the basis of network topology model. Combined with the wavelength rotation strategy, the congestion rate of overloaded services in smart substations is reduced, and the throughput rate of overloaded services in smart substations is improved. Considering the factors of high concurrent users, by judging and feeding back the congestion of the overloaded services of smart substations, the congestion control of overloaded services of smart substations under high concurrent users is realized. The experimental results show that the proposed method has better effect and scalability in the congestion control of the overloaded service of the smart substation, and can effectively shorten the congestion control time of the overloaded service of the smart substation.

Research on Substation Network Security Situational Awareness Strategy and Equipment Remote Operation and Maintenance

Abstract Substation network security is the key to maintaining the stable operation of power systems. In the face of growing threats of network attacks, traditional security protection measures have been brutal to meet the needs of modern power systems. Research on substation network security, situational awareness strategies, and remote operation and maintenance of equipment is essential to improve network defense capability and ensure the continuity and reliability of power supply. This study explores effective security situational awareness methods and remote operation and maintenance techniques to provide new solutions for substation network security. This paper builds an efficient network attack detection model by introducing linear discriminant analysis (LDA) and radial basis function (RBF) neural networks. The experiment uses the KDD Cup99 dataset, which is preprocessed to provide the model training and testing data. The LDA-RBF model in this paper outperforms the traditional RNF neural and BP neural networks regarding recognition rate. Specifically, the recognition rate reaches 90.2% for the Smurf attack and 100% for the Ipsweep attack. The proposed model of the study also performs well in terms of leakage and false alarm rates, with an overall recognition rate of 97.00%. This study proposes a network security situational awareness strategy and equipment remote operation and maintenance method that can effectively enhance substation networks’ security and operation and maintenance efficiency.

Research on Networking of 10 kV Substation Management Information Area

At present, the substation network management information area, as an essential part of the substation network communication, is an important transmission channel to realize the intelligent auxiliary control of the substation network. Establishing a stable and reliable substation management information area network has become an essential part of upgrading the substation network. Firstly, this paper designs a Gigabit-Capable PON, and an industrial Ethernet networking scheme, based on certain city data. Secondly, based on the availability of single-device operation, a calculation model algorithm for reliability analysis is innovatively proposed to realize the comparison of networking solutions. Thirdly, regarding the economy, the concept of unit incremental investment reliability index is applied to two groups of networking solutions comparison for the first time. Finally, a networking scheme and suggestions for the substation network management information area are proposed.

Use of synchronized vector measurements technology for perform relay protection functions

RELEVANCE. Recently, along with the initial scope of synchronized vector measurements (synchrophasor) technology associated with Wide Area Measurement System (WAMS), more and more attention is paid to expanding the scope of this technology. Digital substations are one of the places for generating synchrophasor signals, at the same time, synchrophasor data are proposed to be used for the purposes of relay protection and automation at the digital substations itself, which will facilitate the construction of centralized relay protection systems at the substation. THE PURPOSE. Consider the use of synchrophasor technologies at a digital substation of the fourth type, as a replacement for Sampled Values (SV) signals. Consider additions to the standard set of synchrophasor signals necessary for the operation of various relay protections at a digital substation. Perform an analysis of the accuracy of calculating the synchrophasor when the frequency of the controlled current and voltage changes relative to the nominal value, when higher harmonics appear in the measured signal. Develop a pre-computation technique for relay protection algorithms. METHODS. When solving the problem, the method of calculating the total measurement error of the synchrophasor TVE (Total Vector Error) was used - a value that characterizes the deviation of the amplitude and phase of the measured vector from their specified values. CONCLUSION. The use of synchrophasor signals with the necessary additions for the operation of relay protection reduces the load on the digital network of the digital substation, simplifies the operation of relay protection algorithms. Calculations have shown that the measurement errors of synchrophasor do not go beyond the specified parameters. The proposed methods of precomputation allow to speed up the work of relay protection algorithms.

Digital Substations and IEC 61850: A Primer

Modern electrical substations are managed by intelligent electronic devices communicating through Ethernet-based networks. Because of the highly critical roles of substations, which include safety and protection, electronic devices need to be configured automatically through highly reliable and low-latency networks. This gives substation networks some requirements not addressed by previous industrial network standards. To address these unique challenges, IEC 61850 provides a collection of protocols and a model for the automatic configuration of digital substations. This article briefly overviews this standard and the security efforts to protect substations from attacks.

Investigation and Simulation of Technical Power Losses on 33/11kv Distribution Feeders Based on Gauss-Seidel Iterative Approach

Loss of technical performance is one of the main causes of energy shortages and inefficient operation of electrical machines in energy systems. In this study, an analysis of power losses for six selected 33/11 kV distribution feeders was presented. (Kakoba, Ntare, Karamurani, Ishaka MbararaNorth1 and Mbarara North 2) at Mbarara Central Substation Network of UMEME Electricity Distribution Company in Uganda. Data such as cable type, conductor resistance, conductor reactance, and route length were obtained from energy suppliers. From this data, the Gauss-Seidel method was used to determine the total active power and associated reactive power of the entire substation system. The findings showed that the substation is profitable due to the small calculated total power losses. Although it is possible to reduce the total loss to at least 9-12%. Losses were due to old substations, overloaded transformers, and copper losses core losses in lengthy feeder routes. To improve the performance of power distribution networks, it was recommended to replace old conductors to reduce losses.

Analysis of the Impact of Newly Built Grounding Grid on the Original Grounding Grid Based on the Method of Moments

On the basis of the method of moments, the resistive coupling effect between the newly built grounding network. When the horizontal distance between two grounding networks of a substation changes, this original grounding network of a certain substation is analyzed. And establish corresponding soil models based on actual engineering soil resistivity data. Use the grounding grid analysis function of CDEGS software and Powerstation software simulation software to simulate and calculate some parameters of the new and old grounding grids. The analysis parameters mainly include the grounding resistance, step voltage, and contact voltage of the grounding grid system. And the obtained parameter indicators are compared and analyzed with safety limits to determine the safety performance of the newly built grounding grid system in the substation. And the impact on the grounding performance of the original grounding network of the substation. Provide certain theoretical data support for the actual promotion of substation grounding network engineering.

Implementation of Risk-Aggregated Substation Testbed Using Generative Adversarial Networks

Capturing the anomalies of a cyber system in power control networks would promote operational awareness. Correlation of such events, e.g., intrusion attempts, traffic flow, and other signatures, together with control alarm events gives operators an in-depth understanding in order to make an informed decision. This paper proposes a threat inference framework to promote real-time vulnerability assessment associated with cyber intrusions on power communication networks. Wasserstein Generative Adversarial Networks (WGAN) is proposed to estimate the performance of the adversarial model. Additionally, a machine-learning framework is introduced to model the filtering process of the security devices, i.e., firewalls, isolation, and encryption devices, and the posterior fitting method is incorporated to establish an accurate probabilistic formulation. Finally, a testbed is established to coordinate system evaluation. Verification of the intrusion model is part of the implementation to quantify system risks based on the anomalies using (1) the open-source emulator, and (2) an externally imported system analyzer to characterize resulting impacts. The effectiveness and feasibility of the generative models are verified in a comparison study where the proper parameter settings could be obtained. The proposed framework is justified with extensive studies of substation networks using real-world settings.

Reliability Evaluation of Smart Substation Based on Time-Varying Probabilistic Hybrid Attack Graph

A substation is the portion of a power grid that forms a link between the cyber system and the physical system. Reliability evaluation of smart substations based on a time-varying probabilistic hybrid attack graph (TVPHAG) is studied in this paper. First, the topology network of the smart substation is established, whose attributes are represented by probability. Then, in order to solve the problem of asynchrony in the cyber-physical system and the hybrid caused by heterogeneity, time-varying state equation in topology and cuts in algebra are introduced to TVPHAG. Based on TVPHAG, the evaluation of the reliability of cyber-physical systems with multiple equipment and multiple timescales is established. On this basis, the influences of physical conditions, cyberattacks, physical attacks, and cyber-physical attacks on substations are analyzed, respectively. Finally, the simulation shows that the method is effective in evaluating the reliability of smart substations, providing a new method for the evaluation of reliability.

An Enhanced Industrial Wireless Communication Network for Hard Real Time Performance Substation Automation Purposes

Wireless communication network (WCN) technologies are charming solutions to bolster the conventional electrical substations with the intention of take the fashion of smart substation such as reduction in equipment, minimize the maintenance costs, flexibility, and expansion. However, the harsher challenge facing WCN employing in the electrical substation is the real time protection of substation automation system (SAS) for the high voltage devices in terms of the latency and the reliability in particular the substations of old topologies. This work suggests WCN including special types of the intermediate devices (Switched-Access Points (S-AP) and Multi Wireless Domain- Access Point (MWD-AP)) to address the expected packets congestion by creating independent wireless channels domains offering wireless channels reliability in such network topology that deals with real time data traffic (RT) and the non-real time data traffic (NRT). Riverbed modeler is adopted to simulate the model of the electrical substation network due to the rich tools of communication networks in term of industry environment. The results indicate, the suggested WCN can handle the hard real time requirements of protection from latency and data reliability points of view in case of basic capacity of 802.11a/n standards at the level of ≤ 4 msec and high data reliability.

Research on FDIAs localization and traceability techniques for substation networks

Research on FDIAs localization and traceability techniques for substation networks

Towards Latency Bypass and Scalability Maintain in Digital Substation Communication Domain with IEC 62439-3 Based Network Architecture.

Parallel redundancy protocol (PRP) and high-availability redundancy protocol (HSR) are widely adopted protocols based on IEC 61850 standard to support zero recovery communication networks for time-critical and reliable interactions in power system substations. However, hiring these protocols comes with technical and economic constraints that impact the size of the substation network arrangement. Therefore, we will undertake a theoretical analysis of HSR, PRP, and their combinations to reach a maximum number of nodes in different substation communication architectures regarding IEC 61850 standard message time constraint requirements and IEC 62439-3 standard regulations. We will validate our findings through a simulation in the OPNET Modeler environment. In addition, we considered bandwidth efficiency by prohibiting the extra circulation of packets in the redundancy Box (RedBox) and QuadBox implementation as interfaces for HSR and PRP connection and HSR rings interconnection, respectively, which represent the main hindrance in utilizing the combination of these protocols.

Effect of VLAN configuration on IEC 61850 sampled values

IEC 61850, the standard for communication in power utility, has solved the interoperability problems between different vendors in substation communication networks (SCNs). However, most studies on SCN that use IEC 61850 were conducted using computer-based simulations or commercial equipment with fixed functions. In this study, an experiment on an SCN was conducted using real equipment such as a network switch, Raspberry Pi, and a mini PC. A cyclic data model was used for the traffic generation of sampled values (SVs) according to IEC 61850. The effect of applying a virtual local area network (VLAN) in the SCN on the transfer time and throughput of the SV frames was measured. In addition, when using IEEE 1588 in the time synchronization process, it was verified that the clock offset remained unaffected irrespective of the use of VLANs or changes in the sampling frequency. The experimental results can serve as guidance for the actual planning and construction process of SCNs.

Research on Fault Diagnosis Method of Secondary Equipment in Intelligent Substation

Abstract With the continuous development of power grid scale, traditional substations are gradually replaced by smart substations. In view of the high safety risks of the current power system secondary equipment maintenance and fault isolation work. A new smart substation network structure method for fault diagnosis of smart substations is proposed for the relay protection measurement circuit, and the fault status of the secondary equipment of the smart substation is analysed. First, the timeliness and reliability of relay protection are considered, and the intelligent substation network structure is established. Then, the polarity fault characteristics are analyzed, and the generalized transformation ratio is used to establish the fault diagnosis model of the secondary equipment in the smart substation. Finally, the effectiveness of the proposed method is verified by PSCAD simulation.

Cascading verification initiated by switching attacks through compromised digital relays

Attackers are able to enumerate all devices and computers within a compromised substation network. Digital relays deployed in the substation are the devices with IP addresses that can be discovered in the process of trial-and-error search. This paper is concerned with studies of cyberattacks manipulating digital relays to disruptively disconnect the associated breakers. The plausible enumeration of such disruptive attack for each relay in a substation is verified with the dynamic simulation studies with the special protection system for frequency, voltage, and rotor angle stability. A pertinent approach with smaller scale contingency analysis results is proposed to reduce the enormous computation burden. The devised enumeration reduction method is evaluated using IEEE test cases. The proposed method provides an extensive enumeration strategy that can be used by utility engineers to identify the pivotal relays in the system and can be further strengthened with security protection.

Determination of the reactive power of the ac network of the traction substations

Determination of the reactive power of the ac network of the traction substations

Fault Diagnosis Knowledge Reasoning of Switching Network in Distributed Generation Based on Petri Net

Telephone network based on IMS technology has been widely applied inpower production and dispatching communication, especially in distributedpower stations. Analysis and positioning failure of IMS network is arduous,because it’s dependent on IP data communication network. In this paper,we first introduced IMS switching network architecture and distributed gen-eration communication network architecture, analyzed and summarized allkinds of network malfunction. Combining typical IMS network fault con-nection relations, we introduced an improved Petri net fault handling modeland reasoning method. The diagnosis and positioning results could reflectthe defects of equipment logic functions. This method on fault diagnosisand location of substation network has been proved to be effective throughpractical application.

Smart substation network quality monitoring and fault prediction

The smart substation communication network is the basis for information sharing of various devices in the substation. Its operation status has an important impact on the safe operation of the substation and even the power grid. Therefore, real-time status monitoring of the smart substation communication network is becoming more and more important. Aiming at the problems of single dimension, insufficient real-time performance and manual fault analysis in existing substation communication network state monitoring technology, this paper proposes a method of smart substation communication network state monitoring and fault prediction based on network communication quality. This paper uses switch ACL technology and coloring technology to obtain communication quality indexes such as bandwidth utilization, delay, and packet loss rate in real time; based on a multi-dimensional evaluation algorithm, a comprehensive evaluation model of network communication quality is constructed; the model of the relationship between abnormal network communication quality and failures is established. Finally, real-time monitoring of network communication quality and fault prediction are realized. The application analysis in a typical 110 kV substation shows that this method can effectively evaluate the network communication quality and accurately predict failures, and can guide operationer and maintenaner to quickly restore the normal operation of the communication network.

The Analysis and Display Method of Digital Substation Network Based on Business Chains

In this paper, the status of digital substation network monitoring and message analysis is introduced, the procedures and execution process of the typical business chains are analyzed such as control business chain, relay action business chain, measurement business chain, and the analysis and display method of digital substation network based on business chains is proposed. Taking the control business chain as an example, the model mapping method of business chain and the key information points of the protocols are illustrated. The function of the analysis and display method of digital substation network based on business chains is realized via multi-protocols association analysis. The verification instance is presented, the beneficial effects and further improvement of the method are summarized.

Evaluation of central tendency measures in relation to the parameters of contact network feeders controlled by relay protection

The paper considers the importance of possible input values of standby stages of remote protection of contact network feeders from the point of view of their influence on the reliability of protection. The measures of the central tendency of parameters controlled by relay protection of contact network feeders were evaluated based on the theory of statistics, using the example of the Trans-Baikal Railway for 2018-2019. In total, 14 parameters were measured according to GOST 32144-2013. Electric power. Electromagnetic compatibility of technical facilities. Standards for the quality of electric energy in general-purpose power supply systems, in 2020 on the feeder of the contact network of the Sokhondo traction substation of the Trans-Baikal Railway against 88965290 obtained values, which made it possible to select significant values from all possible parameters on the basis of mathematical analysis. Statistical data on the following parameters were considered and analyzed: effective voltage value, effective current, peak voltage amplitude factor, peak current amplitude factor, harmonic voltage distortion factor, harmonic current distortion factor, phase shift factor, load resistance, angle between the first voltage harmonic on substation buses and feeder current. The reasonable selection of significant parameters proposed by the authors allows improving the operation of standby stages of remote protections of contact system feeders in heavy traffic conditions and increasing their selectivity.