Power System Relay Protection Research Articles

Research on Teaching Reform of Electrical Power System Relay Protection Course based on Engineering Professional Certification

Under the background of globalization and the rapid growth of power technology, the teaching of Electrical power system (EPS) relay protection is facing new challenges and opportunities. The traditional teaching mode and content have gradually exposed the problems of being out of touch with the needs of the industry and lacking practicality and innovation. At the same time, engineering professional certification, as an internationally accepted education quality assurance system, provides a clear direction for the educational reform of power engineering specialty. In order to adapt to this change, this article deeply studies the teaching status of EPS relay protection course, finds its existing problems, and puts forward corresponding reform ideas. In order to meet the development needs of the power industry, this article puts forward a student-centered teaching concept, combines the perspective of liberal arts, strengthens the humanistic care and social responsibility education of the course, and enhances students' communication and expression ability. Through the reform, it is expected to cultivate power engineering and technical personnel with innovative spirit, practical ability and social responsibility, and make contributions to the safe and stable operation of the EPS. In this article, the reform ideas and implementation suggestions are elaborated in detail, which provides useful reference for the education of power engineering specialty.

Design and Application of Virtual Flexible Simulation Experiment Teaching Platform for Relay Protection

Abstract: Power system relay protection (PSRP) is a comprehensive course in electrical engineering undergraduate stage, which has a very strong engineering application. However, due to the influence of many factors, such as the power system security, high experimental cost, limited course hours, insufficient open conditions, and so on, traditional experimental teaching combined with hardware is difficult to meet the needs of students in various scenarios anytime and anywhere. Therefore, a low-cost virtual flexible simulation experiment teaching platform (VFSETP) is developed. The platform uses Simulink to build the simulation model of power system primary system and uses graphical user interface (GUI) to design the human-computer interaction interface. Through the communication between GUI and Simulink model, the protection experiments in various scenarios are successfully simulated. The VFSETP has many advantages such as simple interface, good visualization effect, and simple operation. The teachers can easily use it for classroom demonstration, and the students can use it for verification, analysis, expansion, and exploration of experiments in a variety of application scenarios without relying on the laboratory environment. This experimental mode is very conducive to the understanding of knowledge and the cultivation of practical innovation ability. The results of the student survey show that the design method and application mode of the platform can provide a reference for similar courses.

Research on the Reliability of Power System Relay Protection

Research on the Reliability of Power System Relay Protection

Application and Analysis of Power System Relay Protection Technology

Application and Analysis of Power System Relay Protection Technology

Fault and Analysis of Power System Relay Protection Action

Fault and Analysis of Power System Relay Protection Action

A review on distributed generation impacts on electric power system

In 2021, the world's total installed capacity of generation units based on renewable energy sources (not including hydropower) amounted to about 1674 GW: over 825 GW and 849 GW of wind and solar power plants were installed respectively. The growing of the installed capacity of these distributed generators is a response to the increasing the power consumption, global environmental issues and has also become possible due to the development of technology in field of power semiconductor devices. However, on the way of large-scale implementation of distributed generators based on renewable energy sources, traditional electric power system meets new challenges to ensure the reliability and sustainability of new electric power systems with renewable energy sources. In particular, distributed generators change processes in the electric power system, impact to the parameters and power balance, change the magnitude and direction of power flow and short-circuit current, which determines the need to update the settings of the relay protection and automation systems of traditional electric power system and to coordinate their operation with automatic control systems of installed distributed generators. The above-mentioned tasks form a number of scientific research directions, one of which is a task of determining optimal size and location of distributed generators. The main purpose of this optimization task is to reduce power losses, operating and total electricity cost, improve the voltage profile, etc. In addition, the correct and reasonable placement of distributed generators defines an effective planning of the operating modes of electric power system and power plants (especially based on renewable energy sources, the operating modes of which depend on weather conditions and can be sharply variable).The paper highlighted the impacts of distributed generators on power losses, the voltage level, maintaining the power balance and the possibility of participating in the frequency regulation, and short-circuit current in power system. The optimization criteria, the main limiting conditions, as well as methods for solving this optimization problem are considered. This review will help the System operators and investing companies, especially in Russia, to form the main aim, objective function and constraints that will aid to meet their load demand at minimum cost and to choose from the options available for optimization of location and capacity of distributed generators.

Research on fault characteristic of modular multilevel converter

Along with China proposes to build a new energy power system, various DC transmission technologies have been extensively studied. As the most serious fault type of the DC transmission system, permanent DC bipolar short-circuited fault is easy to cause converter damage. Modular multilevel converter can be used in the DC power transmission and distribution systems because of its modular design and strong ability on handling fault. When permanent DC bipolar short-circuited fault occurs, the research on fault characteristics of modular multilevel converter can offer important support for current-limiting control of converters and relay protection of power system. By analogy with the fault evolution mechanism of two-level converter, the equivalent zero-crossing voltage of sub-module capacitance is defined, and the fault evolution mechanism of modular multilevel converters can be obtained. The expressions of the fault characteristic parameters including the equivalent zero-crossing voltage of the sub-module capacitance, the DC steady short-circuited current, the peak value of the DC short-circuited current and their difference, and the peak time of the DC short-circuited current were deduced. By the way of analysis and simulation, the influence of the main circuit parameters in MMC on the characteristic variables with short-circuited fault can get the regularity, it can provide the theory basis for the current-limiting control and relay protection.

Analysis of Power System Relay Protection and Fault Detection Methods

Analysis of Power System Relay Protection and Fault Detection Methods

Research on Optimal Coordination and Algorithms of Microprocessor-based Inverse Time Backup Protection

Backup protection plays an important role in the safe operation of power grid, and it has important research value in the field of power system relay protection. Firstly, the research status and development opportunities of inverse time limit protection are analyzed, and then the best cooperation between inverse time limit protection and distance protection is discussed theoretically. According to the time constraint relationship in the protection range, an objective function satisfying the selectivity and speed is proposed. Secondly, in view of the difficulty in calculating the inverse time characteristic curve, a processing algorithm combining Taylor expansion method and look-up table method is proposed. Finally, the effectiveness and practicability of the method are verified by simulation experiments.

Design, Modeling and Implementation of Multi-Function Protective Relay with Digital Logic Algorithm

In this paper, three phase transmission power system with three different protective schemes such as over current relay, over and under voltage relay and over and under frequency relay is developed using MATLAB/Simulink toolbox. The protective relay is tested for different operating conditions of the transmission power system such as overload, over and under voltage, over and under frequency conditions. Protective relays are explained with simple flowcharts. We used digital logic algorithm for implementation of protective relay. In this paper, a digital multi-function protective relay was designed and implemented on MATLAB/Simulink. In this study we also explore some current techniques ranging from the use of digital logic algorithms to system protection applications. Mother power system protective relays are digital systems based on digital signal processing of power system voltage and current waveforms.

Analysis on the Influence of Different Setting Conditions on the Short Circuit Current Calculation Results of PSD-SCCP

The result of power system short circuit calculation and verification is important reference for power system relay protection, electrical automatic device setting, transient process research, electrical planning and design and equipment selection. In the process of short circuit calculation, different conditional combination mode may lead to different results. The aggressive conditional combination mode will lead to the decline of power grid security performance, on the contrary, the conservative conditional combination mode will lead to the rapid increase of investment cost, resulting in a certain amount of investment waste. At present, there is no unified short circuit current calculation standard in the industry. Based on the actual power grid calculation example of a province in China, the short circuit current results of six condition combination modes is calculated and analyzed in this paper, expecting to provide an important reference for the setting of short circuit current calculation conditions.

PLC/HMI-Based Implementation of a Real-Time Educational Power System Protective Relays Platform

Engineering laboratories are key elements in engineering learning and are essential for a concrete understanding of engineering topics and experiments. These key laboratories are no longer just hardware-dependent, they are a creative combination of programmable hardware and also user-defined driving software. In this work, an educational power system protective relaying laboratory platform was designed and implemented using a programmable logic controller (PLC) and human–machine interface (HMI) in order to introduce engineering students to the operating mechanisms experimentally. It engaged the students in selecting settings and upgrading the inverse definite minimum time (IDMT) protection relays for overcurrent, overvoltage, undervoltage, and differential current. With the platform and the help of the HMI, the students mastered (or came close to mastering) the field of protective relays, especially those explicitly implemented in the platform. The students were also able to see the real-time response that is equivalent to the relay operation time of the protective relays under the various possible settings, and the kinesthetic learning that was involved gave them a deeper understanding of what is involved in relays upgrading.

Important Considerations for Testing and Commissioning Digital Protective Relays: Avoid Misoperations

The proven advantages of digital technology for power system protective relays are now commonplace in the power producing and delivery industry. Digital relays provide unsurpassed reliability and extended capabilities at an economical cost. Keeping pace with the testing and commissioning requirements of these devices has proven to be a challenge for both protective relay engineers and technicians. Although testing procedures have been well defined for single-function electromechanical (EM) protection devices, modern relay test procedures have been left to the utility to develop, creating possible shortcuts that may compromise the protection system operation.

Research on Power System Relay Protection Method Based on Machine Learning Algorithm

With the development of power industry, there are gradually high permeability distributed energy systems. However, the existing relay protection is difficult to be effectively applied in this type of power system. To solve this problem, this paper applies machine learning algorithm to power system relay protection. Firstly, the structure of power system with high permeability and distributed energy is analyzed, and the challenges which current relay protection algorithms faced are introduced in detail. Then, the artificial intelligence algorithm is introduced, and the machine learning algorithm in artificial intelligence algorithm and its application in power system are mainly studied. Finally, the power system relay protection based on machine learning algorithm is deeply studied, and the specific implementation method and implementation flow are designed. The machine learning algorithm studied in this paper is helpful to the development of technology in the field of power system relay protection.

电力系统继电保护课程教学改革的讨论

电力系统继电保护课程教学改革的讨论

Setting value optimization method in integration for relay protection based on improved quantum particle swarm optimization algorithm

With the establishment of the integrated model of relay protection and the scale of the power system expanding, the global setting and optimization of relay protection is an extremely difficult task. This paper presents a kind of application in relay protection of global optimization improved particle swarm optimization algorithm and the inverse time current protection as an example, selecting reliability of the relay protection, selectivity, quick action and flexibility as the four requires to establish the optimization targets, and optimizing protection setting values of the whole system. Finally, in the case of actual power system, the optimized setting value results of the proposed method in this paper are compared with the particle swarm algorithm. The results show that the improved quantum particle swarm optimization algorithm has strong search ability, good robustness, and it is suitable for optimizing setting value in the relay protection of the whole power system.

Impact of electromechanical wave oscillations propagation on protection schemes

Major disturbances in power system can take place after power system elements such as generators, loads, or transmission lines are suddenly disconnected. Such disturbances can create so called “electromechanical wave oscillations” waves which propagate through transmission lines at much lower speed than speed of light. They can cause adverse effect on power system protective relays. In this paper, electromechanical wave oscillation propagation is modeled, and its impact on different power system protective relays, such as overcurrent, distance, and out-of-step relays is studied. Modified protection schemes are presented for each protective device to avoid their malfunction under effects of electromechanical wave oscillations. The electromechanical model adopted in this study considers the dynamics of generator mechanical shaft as well as conversion of mechanical power to electrical. Simulations used for testing of the improved protection solutions are carried out in MATLAB considering 64-bus generator ring system and IEEE 118-bus system.

STRUCTURE AND TECHNOLOGY OF THE NUMERICAL RELAY PROTECTION IN THE POWER SYSTEMS

Abstract. Numerical relays permit development of new functions as well as development of adaptive relaying schemes. Digital relays, providing flexibility to the user and to electromagnetic and static relays are superior advanced microprocessors, and economic empowerment, increased attention to the supply and use of microprocessor-based protective relays were. This paper introduces the technology of power system relay protection. Refers to the generation of protective relays and upgrade them and eventually to relay the new generation of digital signal processing technology deals.

Research on Short-Circuit Current of Wind Power System and its Impact on Relay Protection

Wind energy is clean and renewable energy with rich resources. As one of the most promising green energy, wind power has become an important part of the electricity supply. But there are still many technical problems to be solved related to wind power generation and integration, because it may have significant impact on safe and stable operation of the power grid. Therefore, the doubly-fed wind generator and direct-driven permanent-magnet wind power generator are studied. Their models are built in PSCAD/EMTDC for electromagnetic transient simulation, in order to study the characteristics of their short circuit fault current, as well as the impact on the relay protection of the wind power system. The research outcomes provide a reference and basis to wind power failure characteristics research.

Relay Protection Setting Calculation and Analysis of Auxiliary Power System for Hydropower Plants

The configuration and setting calculation of auxiliary power protection are directly related to the regular and safe operation of the equipments, thereby affecting the security and stability of the power plant. The system features are analyzed in depth according to the operational requirements of auxiliary power system protection in Xiangjiaba hydropower plant ,the system model is built on the basis of the actual project, and a variety of short-circuit current calculations are carried out. At last, the setting of the auxiliary power system relay protection is completed. This thesis also proposes solutions to the emerging problems in the process of protection setting. The results of the setting have been applied to the actual operation and no misoperation or maloperation caused by improper constant setting value has occurred so far in Xiangjiaba hydropower plant.