Relay Protection Research Articles

Single Event Effect Protection Design of Output Module of Relay Protection Device

Abstract A design scheme for single event effect protection of output modules has been proposed, which combines software and hardware to solve the problem of output relay misoperation or refusal to operate caused by single event effect in the output module of relay protection devices. The core idea is to use dual path independent logic processing in software and dual circuit combination driving control in hardware to ensure that the output of the relay protection device will not misoperate when single event effects occur. The error detection and correction of instruction processing code is designed for MCU on-chip instruction storage areas that are easily affected by single event effects. It executes cyclically, allowing the output module to quickly return to normal after single-event effects occur, ensuring that the device output will not refuse to operate when it is expected to operate. When an irreparable error is detected, the output power supply is locked to ensure that the device output does not misoperate. Based on the experimental verification results, the reliability of the relay protection device is improved through the above methods.

Analysis of Fault Locations Using the Impedance Method on the GIS 150 kV Transmission Line Karang Pilang Surabaya

Transmission lines often experience difficulties in determining the location of interference, due to the length of the transmission line. This interference can be secured by using relays, one of which is a distance relay, this tool secures the zone 1, zone 2 and zone 3 areas on the transmission line. Apart from relays, there is also a tool to determine the fault distance, namely a fault locator. These two tools are examples of protection on transmission lines. The method used in this research uses the impedance method to determine the distance the fault occurs and the settings on the distance relay. This technique is often used in electric power systems and is very effective for transmission lines, such as those in Karang Pilang, because of its ability to detect disturbances in transmission lines and equipment. Based on the analysis results, calculating the fault distance using the impedance method shows that the calculated value is very close to the distance measured by the fault finder. Specifically when a short circuit occurs, the impedance method calculates a distance of 14.35 km, while the fault locator measures it at 14.59 km with a margin of error of 1.5%.

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

Most communication in smart substations uses fiber optic connections to connect secondary equipment now. Due to the lack of intuitive connection between devices, it leads to difficulties in monitoring and relay protection. In order to solve the problems of visualizing, monitoring, and diagnosing secondary virtual circuits in the operation and maintenance of intelligent substations, a comprehensive monitoring technology system for secondary virtual circuits in intelligent substations is constructed. Firstly, a breadth first search algorithm is proposed to sort out the physical connection relationships between secondary devices, which achieves visual display of secondary virtual circuits. Then, based on deep search fault inference algorithms, it can diagnose and locate the fault area. Through the massive data source of intelligent substations, multiple information fusion can be achieved. By applying the D-S evidence theory, precise fault localization can be achieved. Finally, the proof table method is used to determine the type of fault and to meet the practical application requirements for the operation and maintenance of secondary equipment in intelligent substations.

ANALISA SETTING PROTEKSI OVER CURRENT RELAY (OCR) PADA GENERATOR 30 MW UNIT PLTA POSO PT. POSO ENERGY

To ensure that the performance of the protection system is still good or not in terms of protection, calculations and adjustments must be made to the safety relay settings, especially the over current relay. In the research, analysis of the over current relay protection settings on the 30 MW generator at the Poso 1 PT PLTA unit. Poso Energy obtained that the maximum load current data on the generator was 2042 A, while the calculation results obtained were 2041.7 A. For the relay (top) operating time in the specification data, the value was 1.4 s, while in the calculation results it was 1.3 s. And for the setting current (Is) in the specification data the value is 4.7 A, whereas in the calculation results it is 4.28 A. Over current relay (OCR) or over current relay is an auxiliary relay from the differential relay, the over current relay is used to secure the generator of the overcurrent in the Poso 1 PLTA is PCS-985GE-EN-H2-110V-5A. In the specification data, the TMS value is 0.15 s, while in the calculation results it is 0.14 s. This means that data in the field is slower to protect components from interference by 0.01 s. However, overall the overcurrent relay settings on the generator at the Poso 1 PLTA are still in good condition.

Distance optimization and directional overcurrent relay coordination using edge-powered biogeography-genetic algorithms

The effective functioning and regulation of power systems crucially rely on the coordination of distance and directional overcurrent relays. Accurate fault detection and successful clearing sequences require support for each relay and the maintenance of the coordination time interval (CTI) between major distance relays, directional overcurrent relay support, and other relay zones. Efficiently initiating relays while adhering to complex coordination limitations poses a challenging task that demands innovative solutions. This study addresses the intricate problem of relay coordination by employing heuristic methods, specifically genetic algorithms (GA) and biogeography-based optimization (BBO), in both a 9-bus and 39-bus system. The primary objective is to determine the most efficient time setting factor (TSM) that minimizes the duration of relay operation. Additionally, the intelligent features of the overcurrent relay are carefully chosen to enhance the research's results. The integration of edge computing capabilities plays a significant role in advancing this coordination method. By incorporating advanced algorithms and communication technologies at the edge, the prompt activation of relays becomes possible, thereby meeting coordination demands. This study explores the combination of edge-based servers with genetic algorithms (GA) and biogeography-based optimization (BBO) techniques to enhance relay coordination. The findings indicate a notable enhancement compared to conventional approaches. However, comparative research suggests that BBO's performance is similar to GA, without a distinct advantage in achieving higher outcomes.

Development of the Theory of Vector Measurements Applied in Relay Protection and Automation

Development of the Theory of Vector Measurements Applied in Relay Protection and Automation

Electrical Power Systems Reinforcement through Overall Contingency Index Analysis and Improvement

This paper analyzes the behavior of an electrical power system when N-1 contingencies occur in the transmission stage, which can be produced by incorrect operation of the protection relays, phenomena of natural origin, or increased loadability, which affect the operation and reliability of the electrical system. The operation output of a transmission line results in the variation of the nominal values of the electrical parameters involved because they disturb the stability of the generation, transmission systems, and the supply of electrical energy to the loads, such as voltages and angles of the nodes and the active and reactive power of the system. The proposed methodology was based on analyzing the different electrical parameters of the power system, quantifying the contingency index in a state of regular operation, and comparing it to operation in contingency N-1, with which the most severe contingency was determined and, therefore, achieved; identifying contingencies that can cause system collapses; improving the contingency index from 23.08555 to 22.9276624 for the L16–19 contingency and to 22.9795235 for the L21–22 contingency, which are the most severe contingencies determined with the proposed methodology. To test the proposed methodology, the IEEE 39 bus-bar test system was considered, and the elements that should be implemented to avoid the vulnerability of the power system to N-1 contingencies were determined.

System for Automated Calculation of the Operation Parameters of the Relay Protection in 6 – 35 kV Distribution Network

System for Automated Calculation of the Operation Parameters of the Relay Protection in 6 – 35 kV Distribution Network

Quadratic programming-based semi-deterministic approach to find optimal settings for the directional overcurrent relays with user-defined characteristics

Quadratic programming-based semi-deterministic approach to find optimal settings for the directional overcurrent relays with user-defined characteristics

Enhanced distance-based protection for high impedance faults considering dynamic load modelling

The load can be represented by different models, including static and dynamic representations; each has different responses when analysing a power system, which also impacts the protection system's performance. For instance, in the distance relay, the estimated impedance can present overreach or underreach, affecting the selectivity of the protection and causing malfunction of triggering schemes. Under fault conditions, the load modelling effect can be magnified by the fault resistance effect, where the combination of both effects has not been addressed in the revisited bibliography. The present paper analyses the effect of load modelling for non-bolted faults in the distance relay impedance estimation. Distance relays are of interest due to their wide use in transmission systems and the emerging applications in distribution systems and microgrids. The fundamental contribution of the present paper is to propose a countermeasure for the effects of four different load types and fault resistance. The results demonstrate that the distance estimation is correctly enhanced, and then a close to the real positive sequence impedance is estimated from the relay point to the fault point. The proposal can be included in distance relays without requiring additional hardware, allowing countermeasure of the load type and fault resistance effects.

Investigating safety precautions for linking photovoltaic and wind power generation to the grid

The grid integration of renewable energy sources such as solar and wind power has received significant research attention, however, there remains a vast scope for exploration and improvement. Specifically, the discourse around relay protection and safety automatic devices in these power generation methods has been somewhat limited during the grid connection process. This article endeavors to investigate the technical obstacles encountered by photovoltaic and wind power grid protection mechanisms and crucial equipment, amidst the steady growth of renewable energys share in the power grid. This exploration is considered advantageous. The aim is to study and summarize existing research on protective measures and automation equipment for photovoltaic and wind power generation during grid connection, to promote technological innovation and development in this field. This paper critically assesses studies conducted so far on the topic of relay protection and automation hardware used in grid-connected solar and wind power generation, underscoring the significance of different protection techniques and their pivotal roles in ensuring system safety during grid connectivity. It then dives into the present obstacles and constraints that these technologies contend with. In conclusion, it suggests a few potential areas and anticipations for prospective research.

Experimental simulation of the generation of microwave radiation during the interaction of a lightning discharge with an aircraft

On a specialized testing installation — a high-voltage Marx generator, which allows the formation of a spark discharge up to 20 meters long, the process of the impact of lightning radio emission in the microwave range on an aircraft (AC) is simulated. A metal AC model made on a scale of 1:50 was placed in a 9 m long rod-plane spark gap. A positive voltage pulse was applied to the high-voltage electrode from the generator (front 100 μsec, duration 7500 μsec). The generated spark discharge passed through the AC model. It was found that when the spark channel passes through the body of the model, electromagnetic pulses of the microwave range with a duration of less than 500 psec and a rise time of less than 100 psec arise. The measurement of the resulting microwave pulses was carried out using special radio equipment in the subnanosecond range. High-speed photography of the discharge development, carried out synchronously with electromagnetic measurements, showed that microwave pulses (up to 10 GHz) arise at the stage of development of the spark discharge leader in the part of the “high-voltage electrode – insulated model” gap. Such pulses can be considered as a factor dangerous for various AC microwave radio systems, when the AC is struck by lightning, as well as for other objects, including power facilities, which contain equipment with microelectronics. Such microwave pulses can also occur during nearby lightning discharges (for example, in a lightning rod of a power substation), when a powerful streamer corona occurs on devices and wires of ultra-high voltage lines), and when a high-voltage spark discharge occurs when switching equipment (disconnectors, arresters) is triggered. In this case, disruptions are possible in the operation of control equipment (for example, relay protection devices) that contains microelectronics, as well as various communication means available at electric power facilities operating in the microwave range (above 1 GHz).

A novel measurement‐protection‐integrated current transformer based on hybrid core and magnetic field sensor

AbstractCurrent transformers (CTs) are widely used for energy metering, relay protection, condition monitoring and control circuits. However, CT saturation may lead to non‐negligible measurement errors and relay malfunctions, posing a threat to the stability and security of the power grid. In order to address the problem of CT saturation, a novel measurement‐protection‐integrated current transformer (MPICT) is proposed. First, the working states of the MPICT are summarised and the approximate expressions for the steady‐state measuring characteristics, the transient response characteristics, and the measurement errors are derived from the equivalent circuit model. Then, the feasibility of the MPICT and the theoretical analyses are verified by the 3D FEM simulation imitating the presented MPICT excited by diverse currents. Finally, a down‐scale prototype is fabricated and a series of tests are conducted in the laboratory to validate the effectiveness of the equipment. The simulation and experimental results suggest that the output of the MPICT can accurately reconstruct the primary current waveform, even if the primary current contains decaying or constant DC component.

Control and Protection of Medium Voltage Distribution Network Based on Unified Power Flow Controller

The integration of diverse load types, such as large-scale distributed generators and charging stations, presents considerable challenges to distribution networks. The Unified Power Flow Controller (UPFC) provides multiple benefits, including its compact dimensions, cost efficiency, seamless regulation, and swift response. When deployed in distribution networks, the UPFC facilitates the creation of a Distribution Unified Power Flow Controller (DUPFC) system. The DUPFC system enhances medium voltage distribution network regulation but also affects power quality, fault characteristics, and relay protection accuracy. To address these issues, a power flow equivalent circuit model for the medium voltage distribution loop network was developed. The operating principle and steady-state model of the UPFC were investigated, based on distribution loop network parameters and power flow distribution characteristics. A UPFC control strategy was designed to create a suitable DUPFC system for the medium voltage distribution loop network, ensuring coordination between UPFC protection and the distribution system’s protection mechanisms. This system accomplishes rapid fault isolation and automatic load transfer. Finally, a simulation model based on a typical 20 kV distribution loop network structure was selected to validate the effectiveness of the UPFC control strategy and the DUPFC protection system in MATLAB/Simulink.

Detection of Hidden Dangers in 6G Power Grid Relay Protection Based on Support Vector Machine

Detection of Hidden Dangers in 6G Power Grid Relay Protection Based on Support Vector Machine

Temperature Fluctuations in Power conductors: Analysis and Overcurrent Relay Adaptation Strategies for Mitigation

In electrical networks, the efficient flow of energy faces constraints primarily associated with the conductor’s temperature. By assessing transmission infrastructure, identifying critical geographical and climatic zones, one can compute the line’s temperature. Focusing on the importance of maintaining optimal conductor temperature for efficient power transmission, this paper evaluates the critical role of conductor temperature in overhead transmission lines and explores its dynamic variations influenced by various ambient conditions. Emphasizing the significance of maintaining optimal conductor temperature, the study delves into mitigation strategies and adaptive protection mechanism, with a focus on overcurrent relays, with specific emphasis on the efficacy of current-time graphs. By addressing these factors, the research aims to enhance the reliability and efficiency of power transmission systems, ensuring sustained performance under diverse environmental scenarios. Overall, the paper contributes valuable insights to optimize the flow of energy in overhead transmission lines, thereby enhance the robustness also, improving the resilience and functionality of electrical networks.

Optimal coordination of directional overcurrent protection relays using hybrid optimizer

In order to minimize or maximize an objective function, electrical engineering problems might benefit from optimization methodologies inspired by nature. This study employs a hybrid particle swarm optimizer (HPSO) to get rid of local optimum solutions and find the best global one for directional overcurrent protection relays (DOPR) protection. DOPR coordination is a highly constrained, mixed-integral nonlinear optimization problem. An adaptive defense method has been created to counteract the intentionally challenging design. Therefore, design variables such as time multiplier setting (TMS) and plug setting (PS) are utilized for each relay in the circuit. The goal function is to reduce the amount of time spent to trace the fault by all the relays. Reducing the time required for each relay to trace the fault is the aim of function. After analyzing and comparing two test studies of the IEEE benchmark using various optimization strategies, we found that the results for the IEEE 15-bus system has minimum time of 8.9 s, which is improved by 22.92% to 82.89%, and those for the IEEE 30-bus system minimum time of 22.45 s that is improved by 4.41% to 39.6%. In terms of overall DOPR operation and computational time needed to get the global optimum solution, the acquired results are demonstrably superior to those obtained using conventional and state-of-the-art methods.

Accurate fault section diagnosis of power systems with a binary adaptive quadratic interpolation learning differential evolution

Fault section diagnosis (FSD) is essential for ensuring the effective operation of power systems. To determine the faulty sections accurately, we proposed an improved binary adaptive quadratic interpolation learning differential evolution called BAQILDE for solving the FSD problem. By comparing the received warning data with the anticipated states of circuit breakers and protective relays, an analytical 0–1 integer programming function is established. To tackle the resultant function accurately, the population in BAQILDE is directly encoded in binary instead of floating-point to facilitate the solving convenience. Besides, three enhanced strategies including adaptive mutation operator, time-varying crossover rate, and dual transformation operator are developed to equilibrate the population diversity and convergence well to strengthen BAQILDE. To evaluate BAQILDE's performance, four test systems were used for verification, including 4-substation power system, IEEE 118 bus system, and two actual failures that occurred in Guangzhou and Jilin power grids, China. The results show that BAQILDE can diagnose various failures within 0.12 s with 100 % success rate and 0 diagnosis error, consuming an average of 32.21 function evaluation times. It outperformed other well-known peer algorithms in success rate, diagnosis error, robustness, convergence, and statistical analysis, which demonstrates its strong competitiveness in solving the FSD problem.

Optimizing directional overcurrent relay coordination with jellyfish search algorithm

Optimizing directional overcurrent relay coordination with jellyfish search algorithm

Evaluation of Transformer Protection System Coordination at ULTG Jeneponto

Power transformers are essential components in electrical power systems as they transform electrical quantities. In practical terms, electrical power systems may experience disturbances such as short-circuit faults, either between phases or to ground. One type of relay used to accommodate these faults is the Over Current Relay (OCR) for phase-to-phase faults and the Ground Fault Relay (GFR) for ground faults. This research evaluates the coordination settings of transformer protection systems at PT PLN (Persero) ULTG Jeneponto by analyzing the characteristics plot of each transformer unit. The evaluation results reveal intersecting characteristics on the high voltage (HV) and medium voltage (MV) sides of Transformers #3 Tallasa and #3 Bulukumba. By implementing recommended settings for these two transformer units, anomalies can be addressed, and the protection system can coordinate effectively.