Design of a Substation Secondary Equipment-Oriented Error Prevention System Using Wireless Communication Technology and Edge Node Cooperation

A Portable Test Device for Smart Substation Based on PXI Bus

Smart substations are an important part of establishing a strong smart grid. In view of the large variety of secondary equipment in the current power system, the rapid increase in quantity, and the complex working conditions of the current power supply company maintenance classes to inspect substations, a design method for the intelligent operation and maintenance system of secondary equipment in smart substations is proposed in this article. First, the intelligent operation and maintenance system architecture of the secondary equipment of the smart substation is established via Redis and ActiveMQ technologies. Then the system function module model is established. Finally, taking a 220kV substation in a certain area of southern China as an example, a new type of intelligent substation secondary equipment intelligent operation and maintenance system was installed and connected to the main line system, and the effectiveness of the proposed method was verified.

Visualization display and exit fault diagnosis of secondary virtual real circuit in intelligent substation

The intellectualization level and information level of the secondary equipment in the intelligent substation have been greatly improved, which is of great significance for the normal operation of the power system. However, the secondary equipment will generate a lot of redundant alarms information in the EMS system. These alarms are not conducive to finding equipment faults, and there is a lack of an active maintenance method for secondary equipment. In this paper, an intelligent analysis method of EMS alarm information is proposed. This method can find fault alarm information accurately, and we used the actual data of intelligent substation to verify it. A status evaluation method for the secondary equipment is also proposed. The method can be used for early warning of equipment failure and efficient operation and maintenance.

To build a better substation operation and maintenance security state integrated monitoring system, the author proposes an operation and maintenance error prevention technology based on cloud computing. In the relay protection process of intelligent substation, the traditional operation and maintenance error prevention technology has the problem of low timeliness. By calculating the dynamic baseline of relay protection operation in intelligent substations, design the error prevention technology of relay protection operation in intelligent substations, and manage the error prevention data of relay protection operation and maintenance in intelligent substations, complete the operation, maintenance and error prevention of relay protection in intelligent substation in a visual way. The experimental results show that, the designed operation and maintenance error prevention technology has a significantly higher timely rate of operation and maintenance error prevention than the control group, which can solve the problem of low timely rate of traditional technology.

Substations are described in detail in the Substation Configuration Description (SCD) file in Substation Configuration Language (SCL) for intelligent substations according to IEC61850 standard, including primary equipment and topology, secondary smart equipment, measurement and communication, etc. After the SCD file of the downstream substation is got, the corresponding grid logic view for the upstream main station system can be established theoretically. The SCD file is analyzed in this paper, the relationship of primary and secondary equipment model objects of substations are constructed, generating standard spatial point and line model and automatically identifying the wiring of primary equipment, supporting the substation model description according to IEC61970/CIM. With automatic layout and routing technology, the grid panorama is generated, and the relationship of secondary equipment automatically superimposed based on the primary equipment model view is drawn. This technology has important and broad application prospects for easy and convenient maintenance and management of intelligent substations, improving the integration of upstream and downstream information, and intelligent dispatching of grid.

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.

At present, China is vigorously developing the smart grid, due to the immaturity of the intelligent circuit breaker, a totally new device is introduced in the process layer to ensure the realization of intellectualization of primary equipment in the intelligent substation: the. The intelligent terminal is an interface of primary equipment and secondary equipment in intelligent substation system realizing the intelligent transformation of the traditional primary equipment, which is also the optimal solution to the traditional switch and transformer interface problems of intelligent substation. The intelligent terminal devices of 126KVGIS are designed in this paper, the design process adopts the method of ARM+FPGA dual-CPU structure，which makes the intelligent terminal have an efficient and rapid processing capacity so as to satisfy the requirement of practical application. Starting from the modularization structure design, function of each module, circuit design and implementation method were introduced in detail. A hardware platform was established according to the design. Finally, the article confirmed the correctness of the hardware platform primarily through experimental method.

Analysis of ECT effect on accuracy of measurement and protection

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.

This paper introduces a comprehensive performance evaluation algorithm explicitly designed for secondary equipment in substations, specifically targeting the relay protection system. In contrast to the current evaluation systems, this novel method navigates the complex internal interconnections and mechanisms inherent within secondary system equipment. Such complications have previously impeded the accuracy and breadth of evaluations, thereby limiting the degree of precision and innovation attainable within substations. The proposed approach effectively integrates the improved Analytic Hierarchy Process entropy weight (IAHP‐EW) method with the Learning Vector Quantization (LVQ) neural network. Initially, the IAHP‐EW method identified the comprehensive evaluation indicators and their corresponding weights for relay protection devices. Following weight allocation, these evaluation indicators are scrutinized and computed utilizing the multivariate regression analysis algorithm, resulting in performance evaluation outcomes for the relay protection system. These outcomes are subsequently classified and utilized in training the LVQ neural network, promoting the network's capacity to autonomously evaluate the performance status of the relay protection system. To corroborate the viability and effectiveness of this proposed performance evaluation and prediction algorithm, empirical operating data from a local substation is used. The results suggest a significant improvement in the evaluation accuracy of secondary equipment performance, indicating potential for practical application and a valuable contribution to the field through the introduction of a novel approach to performance assessment of substation relay protection systems.

In recent years, a new type of 380V low voltage fixed circuit breakers are used in newly built substations. Fixed circuit breakers without chassis only have two states. They are on and off. They can not provide a clear break point in circuit. So Their isolation function is not obviously. Low voltage equipment in Hub substations should have automatic mutual transfer function. Recently Automatic Transfer Switch (ATS) is often chosen in the newly built digital substation, intelligent substation or large hub substations. Automatic Transfer Switch has interlocking function to avoid the collision of two different power. With the popularize of new equipment such as the 380V fixed circuit breaker and Automatic Transfer Switch, the operation and management of low-voltage equipment in substations puts forward higher requirements as well. The conclusion contains the better ways in operation and maintenance of these new low-voltage equipment.

In order to effectively improve the effect of state unobservable intelligent substation secondary equipment state evaluation and reduce the influence of uncertain factors on the evaluation result, a fuzzy set theory-based intelligent substation secondary equipment state evaluation method is proposed and applied. Firstly, we conduct hierarchical modeling for the intelligent substation and enumerate the different factors affecting the equipment state. Then, the probability of different events affecting the state of the secondary equipment is determined by using the fuzzy set theory and expert knowledge, and the probability of each event is quantified to obtain the secondary equipment state occurrence interval probability. After defuzzification, the state evaluation results of secondary equipment are obtained. Therefore, a conclusion is drawn that this evaluation method of secondary equipment state assessment in intelligent substation based on fuzzy set theory can make more accurate state evaluation, greatly reduce the influence of subjective factors on the evaluation results, and make the evaluation results more stable, reliable and scientific.

With the improvement of domestic power system the demand for electricity in society has been increasing, and the electric power engineering construction projects have gradually increased. With the development of science and technology, intelligent substation is the direction of substation construction at present., intelligent substation as a new trend of future power system development in our country, There are many new technologies involved in intelligent substation, such as digital transformer, network communication, photoelectric technology, etc. Its structure and function are different, and making substation sustainable, stable, safe and economical is still the ultimate goal of intelligent substation construction, and how to detect and maintain the secondary equipment system in the intelligent substation has become the fundamental to ensure the normal and stable operation of the intelligent substation. Therefore, intelligent substation relay protection has become an important research subject. This paper expounds the characteristics of intelligent substation and secondary equipment system and the relay protection debugging and application of intelligent substation., and thinks about a new method that can realize the maintenance and repair of secondary equipment system of intelligent substation and hope to be helpful for future intelligent substation project in China.

Dynamic changes in substation primary equipment and secondary systems are being encouraged by the progress in digital communication and information technology. To survive in the competitive power market a new integrated system has been developed. It aims to introduce simple and compact primary equipment and intelligent secondary systems, as well as easy installation and intelligent substations. The newly developed integrated substation system applies nonconventional CT and VT, electronic signal interface between primary apparatus and upper level for control and equipment monitoring, process bus for realtime data communication, enhanced IEDs with web-server function, and substation control unit for local SCADA. In this paper the basic concept of the developed integrated substation system, features and configuration, technologies applied in each device, and practical examples of the service contents on the web-server are introduced.