Relay Protection Equipment Research Articles

Strategy for evaluating the status of relay protection equipment for the new generation of intelligent substations

With the rapid development of power grid, the structure and technology of the secondary system in substations are also constantly innovating. The new generation of intelligent substations has achieved online monitoring functions for secondary equipment, making some state variables of relay protection equipment become observable indicators. Based on this, this paper proposes a novel relay protection equipment status evaluation strategy. Firstly, considering the fuzziness and uncertainty of the boundary division of relay protection evaluation levels, a relay protection risk assessment method based on normal cloud model has been proposed. Then, due to the particularity of historical statistical data, a weight calculation method combining analytical hierarchy process (AHP) and entropy weight method is adopted to eliminate subjective factors in the weight calculation process. Meanwhile, the equipment operation risk level was determined by calculating the certainty of the corresponding evaluation level for each indicator. Finally, in case study, the proposed method is used to evaluate the status of relay protection equipment, and the feasibility and accuracy of this method are verified through the analysis of the results.

Hotspot Temperature Prediction of Relay Protection Equipment Based on a Physical-Model-Aided Data-Driven Method

Relay protection equipment (RPE) is a type of automation equipment aiming to protect power systems from further damage caused by local faults. It is thus important to ensure the normal operation of RPE. As the power density of electronic components continuously increases, the overheating problem of RPE cannot be neglected. Given the difficulties in implementing direct measurement and predicting development trends of RPE temperature, a novel hotspot temperature monitoring method for RPE was proposed, which is a data-driven method. The generative adversarial network, aided by a physical model, is used to address small samples. Afterwards, a stacked ensemble model established based on random forests was used to predict the hotspot temperature of the RPE. Experiment results show that the proposed method can effectively predict hotspot temperature of RPE with the predictive error lower than 2%. And comparative results demonstrate the superiority of the proposed method compared to other methods.

Automatic verification method of relay protection equipment setting value combining cell image gray enhancement and AI recognition

In order to solve the problems of tedious, insufficient manpower, low efficiency, and easy to cause human errors in the verification of relay protection equipment settings with the development of the power grid, an automatic verification method of relay protection equipment settings combining cell image gray enhancement and AI recognition is studied. In this method, Gaussian mixture and particle swarm algorithm are used to enhance the gray level of the original image captured, and the binary method is used to further denoise the image; The histogram is used to segment the cells in the denoised constant value image one by one; The OCR technology in AI technology uses the maximum width backtracking segmentation algorithm to segment a coherent text in a cell into multiple single words, and collects the 13 dimensional characteristics of the text to be detected to compare with the text in the database. The text with the smallest error is the detected text, which completes the text extraction in the cell; Store the extracted text data in the database, check the data in the notification constant value sheet and the device constant value sheet, and give an abnormal prompt of different data. The experimental results show that the image pre processed by this method is clear, the fixed value single cell segmentation is accurate, and the OCR text extraction efficiency is high. Through a large number of data experiments, the final verification accuracy can reach 99.8%.

Analysis of Immunity of Relay Protection Equipment Under High-Altitude Electromagnetic Pulse

Analysis of Immunity of Relay Protection Equipment Under High-Altitude Electromagnetic Pulse

Condition Based Maintenance Method for Power Relay Protection Equipment Based on Full Life Cycle

Power Relay Protection Equipment (abbreviated as RPE for convenience) is the foundation for ensuring the safe and stable operation of circuit components, and is crucial for the maintenance of power RPE. The traditional regular maintenance method for RPE requires a large number of frontline maintenance personnel to participate. The regular maintenance method can easily cause unnecessary maintenance, and excessive maintenance can lead to resource waste. This article introduced the concept of Full Life Cycle (FLC) cost management for power RPE and obtained the occurrence of faults in the FLC of RPE. This article analyzed the periodic fault occurrence rate of RPE, and fitted the fault curve to analyze the fault rate boundary point. On the basis of the fault distribution curve, the service life regression factor was introduced to obtain the preventive maintenance years, and the actual dynamic changes of preventive maintenance were obtained. The content of RPE condition maintenance was explored by balancing the FLC cost. This article analyzed the transformer RPE and obtained the periodic fault rate of the equipment. The cutoff point for equipment failure rate was 0.02, and the cutoff points for preventive maintenance were the 7th, 9th, and 11th years, respectively. The annuity cost in the 11th year was the lowest. By analyzing the fault status and FLC cost of RPE, the boundary points for equipment fault prevention and maintenance could be determined, and the optimal maintenance plan for RPE could be determined.

State Inference and Evaluation Technology of Relay Protection Based on Digital Twinning

The problems of relay protection equipment in such aspects as the insufficient depth of data mining, not timely grasp of equipment status, and poor timeliness of fault warning restrict the development of the operation and maintenance mode of relay protection, which aims at “autonomous and controllable, safe and reliable, advanced and applicable, intensive and efficient”. This article studies the comprehensive state evaluation and action simulation deduction technology of intelligent substation relay protection equipment based on digital twins. It uses multi-source state monitoring data of relay protection equipment for state quantity correlation analysis. It constructs a key state feature index library and uses digital twin technology to model the relay protection function and software and hardware states. Through the collaborative linkage between physical devices and digital twin models, the twin can dynamically track the operational status of devices and automatically update the twin status. Finally, based on the established high-precision digital twin model, relay protection action deduction and status evaluation are carried out. Then the effectiveness of the scheme is demonstrated through example testing of the relay protection twin system.

Automatic Relay Protection Calibration Device and System Design for New Intelligent Power Grid

Maintaining the protection device and eliminating the abnormal and fault defects of the device are important tasks for the maintenance of the power system. In general, relay protection equipment managers need to regularly check the relay protection device. According to the usual practice, relay protection professionals use the relay protection tester to manually connect. The traditional relay protection verification method has complicated operation, high professional requirements for testers. In this paper, a set of intelligent relay protection verification device with high degree of automation and harmonious human-computer interaction is developed to realize the communication between the host computer and the protection device and the tester. The host computer software and database were developed. The thermal overload protection in the SPAM150C motor protection device of ABB company is verified, and the reliability of the device is verified. The device can improve the efficiency of relay protection equipment inspection, reduce the technical threshold of operators, and reduce the probability of human error. It realizes the process and standardized control of the operation process of relay protection verification which has strong practical application value.

Operation and Maintenance Technology of Relay Protection Equipment Based on Digital Twin Technology

With the scale of the power grid is becoming larger and larger. The corresponding operation and maintenance work of the distribution network is becoming increasingly intelligent, which also puts forward corresponding requirements for the reliability of safe and stable operation of the power grid. The condition assessment of relay protection applies the scientific concept of condition-based maintenance to the actual work site, which is of great significance. To judge the operation status of the equipment and provide a scientific basis for maintenance, in this paper, based on the application of digital twin technology in microgrid operation and maintenance, the method of calculating reliability probability density by function is applied to solve the problems of fuzziness, gray, and randomness of the relay protection status index. The invention can evaluate the state of the relay protection of the power system and can timely and accurately put forward the corresponding relay protection inspection and maintenance scheme, thereby improving the maintenance efficiency of the relay protection and further strengthening the power supply reliability of the power system. It can ensure the security and stability of the power system and reduce the reliable power consumption of the majority of power users.

Optimal Layout and Overheat Monitoring for Components of Highly Reliable Relay Protection Equipment

Optimal Layout and Overheat Monitoring for Components of Highly Reliable Relay Protection Equipment

RELAY PROTECTION DATABASE

The article presents the development of a relay protection database through a series of phases. In the planning phase of the database, problems in a typical relay protection department are examined and the reasons why a database should be developed are determined. Subsequently, during the phase of analysis and the specification of requirements, what the database will be used for is defined. In the phase of the formation and construction of the database, its logic is defined and then a physical model is prepared on a computer using the Microsoft Access database management system, which stipulates how the database will operate. The database is placed into operation and verified using actual data. Training is then provided for the future users. The database presented facilitates the systematization, storage and use of a large quantity of data with minimum redundancy. In addition, it provides support during the regular maintenance of relay protection equipment, the issuing of work orders, periodic reporting etc. The relay protection database can be accessed by several users with differing permissions for individual objects of the database. The right to access is defined by the user identity. Furthermore, a special application has been created to simplify searching updating and printing-out of data, which facilitates the display of a series of previously prepared components of the relay protection database. The basic purpose of the application is to allow the user to utilize the full power of Microsoft Access with a minimum of effort and a minimum of required knowledge about database technique and the system for database management.

Analysis on Maintenance of Relay Protection Equipment in Smart Substation

Analysis on Maintenance of Relay Protection Equipment in Smart Substation

On Combined PSO-SVM Models in Fault Prediction of Relay Protection Equipment

On Combined PSO-SVM Models in Fault Prediction of Relay Protection Equipment

Research on Relay Protection and Security Automatic Equipment Based on the Last Decade of Big Data

The analysis of equipment record, defects and action events of relay protection and security automatic equipment has been carried out in the last decade since the establishment of an electric power company on the basis of relay protection relay protection statistics analysis and operation management module. It can be seen that the growth rate of security and stability control devices is the highest, which is mainly due to the large-scale grid connection of new energy sites; it should strengthen the operation and maintenance of capacitor protection, and stock up spare parts that are prone to frequent defects, such as triggering-power module of capacitor protection for FSC in the severe electromagnetic environment; the number of primary equipment faults and protection actions shows seasonal characteristics, most of which occur in windy, summer thunderstorm weather. The data-driven screening of familial defects, evaluation of operation and maintenance strategy for aged equipment and spare parts management have been actively explored to improve lean management.

Substation Equipment Spare Parts’ Inventory Prediction Model Based on Remaining Useful Life

A large variety of high-value substation relay protection equipment occupies a considerable amount of inventory space and capital in electric power companies. To improve this problem, this study proposes an inventory prediction model based on the remaining useful life (RUL) of equipment. The model acquires the RUL data of equipment by using the support vector regression (SVR) algorithm, and then, by taking this data as the main factor and the environmental factors and human factors during the operation of equipment as secondary factors, the model can realize the prediction of relay protection equipment in the substation. At the same time, the nature of the enterprise and the requirements for safety inventory are considered. The comparison of calculation results and error analysis, as well as the calculation time, all indicate that the RUL-based inventory forecasting is the best one. This model not only has high prediction accuracy but also has strong stability and portability. The model can provide a strong decision basis for improving the inventory management of the enterprise, enhancing the resource allocation capability, and formulating the spare parts procurement plan under the condition that the spare parts inventory reaches the safety stock.

Метод оценки индукционных помех, наводимых на системы релейной защиты, автоматики и управления высоковольтных подстанций

Предложен метод оценки электромагнитных помех от токов, наводимых на аппаратуру релейной защиты и автоматики, размещаемую вблизи высоковольтного оборудования. Вычислительный метод основан на расчете пространственной конфигурации электромагнитного поля с помощью разбиения токопроводящей системы на участки и вычислении пространственных и токовых коэффициентов влияния от единичного тока. Используя в расчетах реальные токи в электрооборудовании, полученные, например, от регистраторов аварийных событий, метод позволяет определить пространственное положение и ориентацию аппаратуры с допустимым уровнем электромагнитного влияния.

Research on automatic physical testing method of relay protection equipment through data fusion technology

Intelligent substations can accomplish deeper and more complex substation information exchange and processing by virtue of their equipment intelligence and data integration. In this paper, a relay protection equipment test system for intelligent substations is investigated for intelligent relay protection equipment. By applying data fusion technology in the testing process, functions such as automatically obtaining the action information of secondary devices and judging the response status of secondary devices can be accomplished. Applying the test system proposed in this paper to high-voltage line protection devices, the results show that the relay protection equipment test system can optimize the relay protection equipment test process, which further improves the accuracy and efficiency of relay protection equipment testing.

Аналіз роботи реле частоти із застосуванням цифрової системи тестування

We were given the task of automatically checking the characteristics of the digital frequency relay. To test and configure complex devices of relay protection and automation, which are digital frequency relays, there have been used special technical means using digital technology. Therefore, this problem is solved by creating algorithms to verify the characteristics of the operation of the typical and special characteristics of the digital frequency relay. On the basis of algorithms the specialized module of check of the frequency relay which became a subsystem of domestic digital test systems of check of devices of relay protection and automatic equipment “RZA-Tester”, “Relay-Tester” and “RTS-M” is created. The developed module allows to check almost all characteristics of the domestic digital frequency relay of the URCH-3M series in the modes of automatic frequency unloading, frequency automatic restart, automatic frequency unloading with blocking on speed of decrease in frequency, control of speed of decrease in frequency. The functional unit of the specialized module allows to check all the characteristics of the frequency relay in one cycle and significantly reduce its testing time. The frequency relay test module showed high efficiency at the stage of manufacturing the URCH-3M series frequency relay on the technological lines of the RELSIS research and production enterprise and during the adjustment of the frequency relay in the power systems of Ukraine.

Measurement Uncertainty Evaluation of Transmission Line Parameters

Transmission line parameters vary with environmental and operating conditions, thus introducing uncertainties in power flow studies and protection zone settings of relay protection equipment. Variations in line parameters are fundamental for the determination of static and dynamic line power ratings. Usually, nominal values are given without an associated confidence interval, and therefore an important piece of information is missing. With the proliferation of phasor measurement units (PMUs) that allows for synchronized measurements at different geographical positions arouse the possibility for simple and efficient measurements of line parameters. This article analyzes uncertainties associated with the estimation of line parameters, based on the equivalent $\pi $ model, valid for short-and medium-length transmission lines. This problem has been addressed in literature, but only from a theoretical perspective and the obtained results were verified with simulations only. Here, measurements conducted on two 220-kV transmission lines are analyzed. It was found that the correlation between voltage and current measurements must be taken into consideration when analyzing uncertainty propagation law. Only then statistical analysis of estimations matches the predictions obtained by applying the theoretical model. Accuracy limits were analyzed as well, but in this case some results were within the calculated limits, while others did not follow predictions. Improvements in accuracy limits’ determination require the separation of environmental and operating condition variations from deviations due to measurement equipment, thus requiring additional information.

Проблемы обеспечения сейсмостойкости объектов электросетевого хозяйства при землетрясениях

The electric grid system is the basis for functioning of the Unified electric power system of Russia and technologically isolated electric power systems. One of the most serious problems in the electric power industry is the aging of the fixed assets of already built and operating power grid facilities. The second problem is to clarify the seismic hazard of the territories of the Russian Federation in the direction of its growth. As a result, the number of power grid facilities fall into the zones of increased seismic hazard. In the zone of 7 points or more, approximately 30 % of the entire length of electric networks and transformer capacities are located. Information is provided about the characteristics of seismic load and how the objects respond to an earthquake. The experience of earthquakes testifies to the high vulnerability of the overhead power lines, cable power lines, substations, power transformers, relay protection equipment and automation under intense seismic loads. Information is provided about massive damage to the power grid during earthquakes in the territory of Russia, Armenia, and other countries of the world. Frequently occurring short circuits during earthquakes in electrical networks, at transformer substations, in electrical equipment elements of power grid facilities lead to fires. It is determined that power grid facilities have less seismic resistance than electric power generation facilities, than buildings and structures where electrical equipment is located. The problem of insufficiency of the current regulatory framework for ensuring seismic resistance of electric power facilities was also identified. Possible measures to prevent accident rate and increase the resistance, reliability, and seismic stability of power grid facilities in case of earthquakes are considered. The development of normative regulation will allow to take measures to ensure the seismic stability of power grid facilities in operation, and to ensure that control and supervision activities are carried out at a higher level.

Simulation Application and Research of Relay Protection Project under Virtual Reality Technology

The accurate and fast action of relay protection devices is an important guarantee for the safe and stable operation of power systems. In order to overcome the limitations of traditional training, this paper builds a simulation system of relay protection for substations based on virtual reality technology, so that trainees cannot only pass the man-machine Interactive operation to understand the appearance and basic operation of the equipment intuitively, and to check the action of the relay protection equipment under different faults through fault settings. Practical application shows that the system is of great significance to improve the quality of staff and ensure the safe and stable operation of the power system.