Power Circuit Breakers Research Articles

Adsorption and work function type sensing of SF6 decompositions (SO2, SOF2, SO2F2, H2S and HF) based on Fe and Cu decorated B4CN3 monolayer. A first-principles study

During frequent arc-quenching operations, SF6 gas in SF6 power circuit breakers decomposes into sulfur-based gases, which eventually causes weakening of quenching ability of SF6 gas. Therefore, such decompositions must be sensed and captured timely to avoid any malfunctioning of SF6 circuit breaker. Here we investigate the sensing/adsorption and release of SF6 decompositions (SO2, SOF2, SO2F2, H2S, and HF) on a monolayer B4CN3 through first-principles calculations. Pure B4CN3 is unable to capture gas molecules due to insufficient adsorption energy, resulting in their rapid release. However, with Fe and Cu decoration on B4CN3, adsorption and release are greatly improved. The mechanism included evaluating band structure, work functions (Φ), and transport transmission (I-V). The order of gas adsorption/sensitivity of Fe and Cu decorated B4CN3 to target gases is SOF2 > SO2F2 > SO2 > H2S > HF. Moreover, despite having lower adsorption energies, Cu decorated B4CN3 is more sensitive to all gas molecules than Fe decorated, indicating no direct impact of higher adsorption energy to sensitivity. Gas molecule release time at room temperature can be reduced to nanoseconds either by rising the temperature to 499 K or by just exposing to UV radiation. Our study presents theoretical insights into the gas sensing capabilities of Fe and Cu decorated B4CN3 monolayers for SF6 decompositions.

Beyond seen faults: Zero-shot diagnosis of power circuit breakers using symptom description transfer

Power circuit breakers (CBs) are vital for the control and protection of power systems, yet diagnosing their faults accurately remains a challenge due to the diversity of fault types and the complexity of their structures. Traditional data-driven methods, although effective, require extensive labeled data for each fault class, limiting their applicability in real-world scenarios where many faults are unseen. This paper addresses these limitations by introducing symptom description transfer-based zero-shot fault diagnosis (SDT-ZSFD), a method that leverages zero-shot learning for fault diagnosis. Our approach constructs a fault symptom description (FSD) framework, which embeds a fault symptom layer between the feature layer and the label layer to facilitate knowledge transfer from seen to unseen fault classes. The method utilizes current and acceleration signals collected during CB operation to extract features. By applying sparse principal component analysis to these signals, we derive high-quality features that are mapped to the FSD framework, enabling effective zero-shot learning. Our method achieves a satisfactory recognition rate by accurately diagnosing unseen faults based on these symptoms. This approach not only overcomes the data scarcity problem but also holds potential for practical applications in power system maintenance. The SDT-ZSFD method offers a reliable solution for CB fault diagnosis and provides a foundation for future improvements in symptom-based zero-shot diagnostic mechanisms and algorithmic robustness.

IoT Based Remote Low Voltage Power Circuit Breaker System in Flood Areas

IoT Based Remote Low Voltage Power Circuit Breaker System in Flood Areas

A theoretical model considering the photochemical and photothermal behavior of arc radiation-induced gassing materials ablation

In this study, we introduce a theoretical model designed to explore both the photochemical and photothermal behavior of arc plasma radiation-induced ablation in gassing materials. We employ time-dependent density functional theory to analyze the photochemical behavior, while reactive force field molecular dynamics are used to explore the photothermal behavior. The phenomena, behavior and consequences of valence shell electronic excitation are analyzed in terms of ultraviolet (UV) absorption, electron-hole distribution, and Mayer bond order. Based on the photochemical findings, we apply a periodic electric field that corresponds to the vibration frequency of the permanent dipole moment to simulate infrared radiation, and convert UV photon energy into atomic kinetic energy to analyze UV radiation. This atomic-scale insight into photothermal behavior enables us to identify the final composition of ablation gases, including H2, CO, H2O, NH3, as well as specific cyanides, amines, and hydrocarbons. The results of the theoretical model and physical properties indicate that the concentration of hydrogen-containing gases in the ablation gas significantly affects the arc extinguishing capabilities of different polymers. Finally, we propose modification schemes suitable for polymers in power circuit breakers, considering UV absorption and smoke black production. Additionally, we present the potential application of theoretical models for calculating the ablation rate, necessitating further in-depth re-search.

Optimizing Power Grid Stability with Enhanced Circuit Breaker Maintenance

This study aims to evaluate the effectiveness of maintenance techniques on 20 kV Power Circuit Breakers (PMTs) using the Research and Development (R&D) method. Key performance variables assessed included contact resistance, PMT synchronism, and insulation resistance. Findings revealed that contact resistance for all phases was below 100 µΩ, indicating optimal connectivity. Synchronism testing showed time differences of 0.7 ms during opening and 1.05 ms during closing, both within acceptable limits. Furthermore, insulation resistance exceeded the 20 MΩ standard, confirming the insulation's integrity. These results suggest that regular maintenance using precise measurement techniques ensures the continued reliability and safety of MV electrical delivery systems. Highlights: Rising Electricity Demand: PT PLN (Persero) faces increasing electricity needs. Advanced Protection Solutions: Innovative equipment addresses conventional limitations. Research Insights: Findings ensure safety and reliability in medium voltage systems. Keywords: Contact Resistance, Insulation Resistance, PMCB, Synchronism Testing

An IoT Design Effectiveness and Reliability of Electric Power Circuit Breakers

An IoT Design Effectiveness and Reliability of Electric Power Circuit Breakers

Adsorption and sensing SF6 decomposed gases (SO2, SO2F2, SOF2, H2S, and HF) on Ti and Co decorated B4CN3 monolayer- A DFT study

With frequent switching of high power and high voltage circuits, SF6 gas decomposes into low fluorine gases, which causes deterioration of SF6 gas. Therefore, such decomposed gases must be sensed and captured timely for the smooth operation of the SF6 power circuit breaker (PCB). The current study aimed to employ density functional theory (DFT) calculations to explore the adsorption and gas sensing properties of SF6 decomposed products (SO2, SO2F2, SOF2, H2S and HF) on titanium (Ti) and cobalt (Co) decorated B4CN3 monolayer. The findings revealed that pure B4CN3 could not capture gas molecules with sufficient adsorption energy and faced instantaneous release. Similarly, Ti and Co decoration can significantly activate the B4CN3 for adsorption and gas sensing. Adsorption analysis showed that SO2, SO2F2, SOF2, H2S, and HF chemically adsorbed on Ti decorated B4CN3 monolayer having adsorption energy of −1.31, −1.61, −1.35, −1.20, and −1.01 eV. Whereas, gas adsorption on Co decorated B4CN3 has −1.29, −1.58, −1.31, −1.18, and −0.95 eV, respectively. The gas sensing mechanism was evaluated by calculating band structure, work functions, and transport transmission. Despite having comparatively lower adsorption energies, Co decorated B4CN3 was found to be more sensitive to all gas molecules than Ti decorated B4CN3. The release time of gas molecules at room temperature can be shortened to nanoseconds either by rising temperature to 498 K or by just UV exposure at 298 K. Our study provides some significant theoretical insights into the gas sensing abilities of Ti and Co decorated B4CN3 monolayer for sensing SF6 decomposed products.

A zero-shot fault attribute transfer learning method for compound fault diagnosis of power circuit breakers

Diagnosis of compound mechanical faults for power circuit breakers (CBs) is a challenging task. In traditional fault diagnosis methods, however, all fault types need to be collected in advance for the training of diagnosis model. Such processes have poor generalization capabilities for industrial scenarios with no or few data when faced with new faults. In this study, we propose a novel zero-shot learning method named DSR-AL to address this problem. An unsupervised neural network, namely, depthwise separable residual convolutional neural network, is designed to directly learn features from 3D time-frequency images of CB vibration signals. Then we build fault attribute learners (ALs), for transferring fault knowledge to the target faults. Finally, the ALs are used to predict the attribute vector of the target faults, thus realizing the recognition of previously unseen faults. The orthogonal experiments are designed and conducted on real industrial switchgear to validate the effectiveness of the proposed diagnosis framework. Results show that it is feasible to diagnose target faults without using their samples for training, which greatly saves the costs of collecting fault samples. This will help to accurately identify the various faults that may occur during CB’s life cycle, and facilitate the application of intelligent fault diagnosis system.

Switching attack modeling and vulnerability analysis of generator for dynamics study

This paper presents novel insights about cyber-attacks in the power network and their consequence in terms of stability. Compared to existing cyber-attack related studies in power systems, the work discusses switching attack construction and evaluates the impact on generator dynamics. As such, the study is in two folds: (i) switching attack construction, with selection of switching instants based on system states and (ii) vulnerability analysis of power system components, circuit breaker, governor system and excitation system of generators. The role of inherently present communication delay/state variable delay becomes important as it has direct impact on dynamic performance of the system. The impact of the constant and timedependent delay on the stability is addressed by determining the time-delay margin using Lyapunov-Krasovskii functional. Thereafter, the condition for successful switching attack construction is given in terms of delay margin. The accuracy of the derived condition for successful switching attack is demonstrated via real-time co-simulation (RTDS) and MATLAB software. The vulnerability of power system components in IEEE 3-machine, 9-bus network are analysed as individuals or their combinations when subjected to switching attacks. The adequacy related to power system stability as a consequence of cyber-attacks is investigated with an estimation of RoCoF of generators.

Assessment of extremely low frequency electric and magnetic field of 400kV transmission lines and substations in Oman

The present study is centered on the investigation of longitudinal and lateral profiles of Extremely low-frequency Electromagnetic field experiments conducted at three distinct locations in Oman. The investigation encompasses findings obtained from 400kV transmission lines and substations. The analysis of electric and magnetic fields emitted by transmission lines was conducted using an EHP-50F E&H field analyzer sensor set and an environmental meter. The measurements were conducted at 400kV transmission lines or to a distance of the insignificant field at the high-voltage substation, various components such as power transformers, CT (current transformers), PT (potential transformers), circuit breakers, reactors, earth switches, transport couplers, lightning arrestors, and other. This research in Oman marks the initial exploration of various factors pertaining to the Oman Electricity Transmission Company (OETC) and its technical standards, which are founded on optimal practices. These factors encompass the interphase spacing, the spacing between conductors within a bundle of twin conductors, the configuration of phases on a tower, the crosssectional area of conductors, and similar considerations. The proposed study aims to support the Sultanate of Oman's objective of establishing a high-quality smart transmission grid by 2030. This system will facilitate the efficient, reliable, and secure transfer and distribution of power, while also offering economic benefits. This research aims to cater to the needs of students and engineers by offering a highly practical approach that utilizes appropriate equipment. This article presents a systematic approach to the implementation of a smart transmission grid, incorporating the aforementioned attributes.

Condition Assessment of Power Circuit Breakers Based on Machine Learning Algorithms

This paper presents two approaches to power circuit breakers condition assessment. The first one covers a wide variety of machine learning classification algorithms where the input for the classification is a manually selected feature set. The second one utilizes deep learning classification based on the convolutional neural network. Both approaches revolve around the idea behind spectral kurtosis, one of which exploits its visual representation in the form of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">kurtogram</i> . The first approach uses a spectral kurtosis curve as the base for feature extraction while the second approach uses a spectral kurtosis kurtogram as a single input into the convolutional neural network. The validation is performed on a large set of vibration signatures and compared to competing state-of-the-art algorithms. The results indicate promising features of the proposed approach.

To Judge the Power Circuit Breaker Interrupting Time and the Prediction of Maintenance Schedule with Normal Distribution Probability

In this article, begins with the motivation for compiling, literature review, and normal distribution theory and characteristics with a shallow example to explain.&#x0D; Design Method: Making an approximately qualitative normal distribution with EXCEL software. First, the sample group plays an important role in the article, it with the cooperation of EXCEL application software and normal distribution rules, can be establish what those the relevant parameters of normal distribution. Taking the relevant parameters to drawn into a bell-shaped curve graph, then the standard score and probability of the area of the bell-shaped curve is out of converted. &#x0D; Design Purpose: As a detection tool of judgement.&#x0D; In this way, an approximately qualitative normal distribution is been formed and its mean, variation and standard deviation are been took as a detection based to evaluated what the probability of any random variable of the same type.&#x0D; Design Effectiveness: To judge of equipment inspection data and work schedule prediction. However, an approximately qualitative normal distribution is been constructed with actual data to calculate out of being relevant parameters, with those ones to judge the interruption time of the circuit breaker what it good or bad in standard value. Another case that was estimated what the probability of arrival time for equipment's spare part with known parameters of qualitative normal distribution. Then review the confusing symbols in the above-mentioned construction design and explain in detail, so as to thoroughly understand the relationship between the parameters of the normal distribution theory. This article demonstrates writing skills with both text and pictures and operational instructions to enhance learning interest and aim to apply what you have learned.

D-Distance Technique to Determine Failure Probability of Power Circuit Breaker

In this paper, a new D-distance factor is proposed to determine the failure probability and to prioritize maintenance actions of power circuit breakers in high-voltage substations. The D-distance factor is calculated by using the condition index and renovation index of a high-voltage circuit breaker (HVCB). To facilitate effective decision-making on maintenance with a simple method and less computational effort, the proposed model incorporates the weighting–scoring method (WSM) and analytical hierarchy process (AHP) with the various diagnostic methods for condition index assessments as well as the operation requirements of HVCBs for renovation index assessments. Many significant parameters from circuit breaker testing, such as insulation resistance, contact resistance, contact timing, SF6 gas measurements, gas leakage rate, visual inspection, etc., have been considered for condition index determination. In addition to these, other significant parameters, such as age of the circuit breaker, age of the interrupter and mechanism, number of fault current interruptions, actual load current to rated current ratio, actual short circuit current to rated interrupting current ratio, maintenance ability, spare parts availability, maintenance expertise level, etc., are also considered for renovation index determination. To validate the proposed model, the practical test data of twenty 115 kV HVCBs in various substations of a distribution utility in Thailand were utilized and tested. By analyzing the actual condition and operation requirement of the circuit breaker, the output, as the condition index and renovation index using the proposed method, is discussed with HVCB experts in the utility to adjust the scores and weights of all criteria to obtain the most accurate and reliable model. The results show that the D-distance technique measured from the risk matrix, which is defined as the failure probability, can be used to rank the maintenance schedule from urgent to normal maintenance tasks. In addition, various failure probabilities in the risk matrix of the circuit breaker can be used to determine the appropriate maintenance strategies for the power circuit breaker in each group. Finally, the proposed method could help the utility managers and maintenance engineers manage the maintenance planning effectively and easily for thousands of HVCBs in the grid, and it can be further applied with other high-voltage equipment in both transmission and distribution systems to facilitate the maintenance activities according to available costs and human resources.

Engineering and design of a novel high-current source for testing low-voltage electrical equipment

This article presents the specification and design of a low-voltage high-current source with a capacity of up to 65 kA and 1 kV for testing electrical equipment such as low-voltage power circuit breaker switchgear, metal-enclosed switchgear, transformers, and cables, among others. Tests that can be performed with the proposed source include the short-circuit withstand on the low-voltage side of transformers, verification in temperature rise limits on electrical power connectors and transformers, and other compliance tests on power circuit breaker switchgear and controlgear assemblies. The design results from the comparison of general topologies of high-current sources according to the literature and test requirements established in current IEEE and IEC standards. In addition, the low-voltage high-current source emerged as a need for the Colombian electricity sector and will help comply with the test guidelines for switchgear and other low-voltage equipment, according to the national standard, also contributing to reducing costs of conducting tests abroad. The specification of the source resulted in the definition of three operating ranges for different types of tests, equipment, voltage, and current levels. Moreover, the general scheme of the low-voltage high-current source is provided with a description of the major components, namely, the novel medium- and low-voltage power modules based on the parallel and series arrangements of toroidal transformers to obtain levels of current and voltage of up to 65 kA and 1 kV, and the switching and protection, control, and measurement systems. Finally, a discussion of the results is presented, and the conclusions are highlighted. © 2017 Elsevier Inc. All rights reserved.

Determination of Maximum Acceptable Standing Phase Angle across Open Circuit Breaker as an Optimisation Task

There are several threats that require the control of the conditions of switching operations in the transmission grid. They result mainly from the negative effects of the high-value current, which may appear after the breaker is closed. Problems considering closing the power circuit breakers on a large standing phase angle (SPA) are often formulated by grid operators. The literature most often discusses the problem of SPA reduction, which allows the system to be restored without the risk of damaging the turbogenerator shafts. This reduction can be achieved by various operational solutions; most often, it is the appropriate adjustment of active power generation, sometimes backed up by partial load shedding. The subject of the presented article is a slightly different approach to the SPA problem. The method of determining the maximum value of SPA for which the connection operation allows to avoid excessive transitional torques was presented. With this approach, finding the maximum value of SPA between the two considered system nodes is treated as an optimisation task. In order to solve it, the original heuristic optimisation method described in the article was applied.

Improvement of Midle Voltage Network Protection System at Kualanamu International Airport

The electricity grid protection system at Kualanamu International Airport is urgently needed. The purpose of protection in addition to maintaining the reliability and stability of the electric power system also functions to detect disturbances, prevent damage to equipment (equipment & networks), protect humans and minimize outages in the event of a system disturbance. flight safety operations, services to passengers, operations, and equipment work at Kualanamu Airport. Safety or protection settings are based on the characteristics of the protection installed in the distribution system, which greatly affects working time, from the protection security area if there is a failure in the main protection. determine the setting of the overcurrent relay against overcurrent disturbances that may occur due to short circuit faults. To simplify the calculation of the disturbance analysis, it is simulated using the Electric Transient and Analysis Program (ETAP) Power Station12.6 software. The relay protection that is used and set is the overcurrent relay at the Kualanamu Airport Medium Voltage Network Sub Station. This relay functions to protect fault currents against ground-phase, ground-phase, ground-phase, and 3-phase. The protection relay setting refers to the provisions in force at PLN, namely for the interruption time of the 20 kV network disturbance at the substation from the time of a disturbance to the extinction of the electric arc by the opening of the power circuit breaker (PMT) the feeder is: less than or equal to 400 milliseconds and for ground-phase short circuit faults NGR12 maximum disconnection time of 500 milliseconds, NGR40 maximum disconnection time of 1000 milliseconds.

Research and Application of Electromagnetic Wave Signal Acquisition Device for Power System Circuit Breaker

Power circuit breaker is an important tool to satisfy the controllability and safety of power system. Therefore, to ensure the stable operation of the circuit breaker is to ensure the normal supply of electric energy. In order to better capture the electromagnetic wave signal radiated by the circuit breaker and better judge the state of the electromagnetic wave radiated by the arc of the circuit breaker, a new type of vibration trigger device specially used for collecting the electromagnetic wave signal radiated by the circuit breaker and its use method are proposed in this paper. This method can collect the electromagnetic wave signal of circuit breaker through the optimized design of vibration trigger device. The device uses all metal integrated cast aluminum shell and independent power supply. This device can effectively resist electromagnetic interference, and is convenient for the acquisition of electromagnetic wave signal. The device developed in this paper and its application method belong to the field of off-line detection of electrical equipment, and are especially suitable for vibration triggering of the device when collecting the radiated electromagnetic wave signal during the action of circuit breaker.

Short-circuit Current Reduction in Auxiliary Network of Traction Substations

The article analyzes short circuit current reduction due to three main factors: electrical arc, cable heating and contact and coil resistance in auxiliary network of traction substations. The research was made using ETAP software module Unbalance Short Circuit, where mathematical model of dynamic arc, as it is described by Russian and abroad scientists, iterative cable heating as it is described in Russian and European standards and contact resistance were implemented. Mathematical model includes power grid, auxiliary transformer, circuit breakers, current transformer, and cable. Cable size varies to show influence of each above-mentioned factors. Calculations were made using phase domain method and all the parts of auxiliary network were considered. The results show up to 60 percent decrease in three-phase short circuit current considering three factors together. It influences the ability to trip short circuit current by backup protections, fault-clearing time, cable sizing and the power supply quality. Neglect of one or more factors may, in some cases, mean insensitivity of the protection and the inability to trip the short circuit current in time.

A Systematic Method for Power System Hardening to Increase Resilience Against Earthquakes

Although natural disasters have recently imposed enormous damages to power system infrastructures, resilience enhancement through hardening measures is not usually compensated in conventional power system planning. In this article, a framework is proposed to enhance the resilience of distribution systems against earthquakes. In particular, it focuses on substations’ retrofit whose failure can affect the distribution system, imposing outages to the customers connected to it. A knapsack based heuristic method, which considers the bus configuration of substation is proposed to select the substation components for hardening. The potential failure of substation components that would lead to complete unavailability of substation is evaluated through minimal cut set-fault tree analysis. A criterion for resilience enhancement is proposed, including hardening cost, cost incurred by damaged components, cost of customers’ interruption in the distribution system level, and power generation cost of Distributed Energy Resources. A penalty mechanism taking into account the component repair time is used to estimate interruption costs. The impact of earthquakes on substation components is modeled using fragility curves. A case study with real earthquake characteristics is considered and Monte Carlo simulation is used to capture the stochastic failure of substation components. The results show that power transformers and circuit breakers at 20 kV are the most critical components in the retrofitting strategies.

Integrated Multiport DC Power Flow Controller With DC Circuit Breaker

Power flow controllers and circuit breakers are important devices in a DC grid, and combining them and expanding their ports can save many components. This paper proposes an integrated multiport DC power flow controller with a DC circuit breaker that can achieve power flow control and fault removal on multiple DC lines during steady and fault states, respectively. First, the device's topology based on modular multilevel converters is proposed, and the principles of power flow control and self-power balance based on bridge arm voltage are introduced. Second, it is improved by adding a fault removal capability. The equivalent circuit and fault currents in different time sequences are analyzed, and the component parameter selection method is designed. Third, in the PSCAD/EMTDC, the power flow control and fault removal capabilities are verified using three conditions: flow control, line fault, and bus fault. Finally, the number of components and steady-state losses are analyzed. Overall, the proposed device has power flow control and fault removal functions as well as a certain limiting effect on the fault current, which greatly reduces the system construction cost.