Circuit Breaker Operation Research Articles

Research on motion characteristics and stability of 500kV fast mechanical switch

The key component of fast mechanical switch (FMS) is electromagnetic repulsion mechanism (ERM), and the stability of ERM has an important influence on fault breaking time and breaking performance of hybrid DC circuit breaker (DCCB). In this paper, a FMS based on ERM is designed. In order to improve the stability of the FMS, the key factors affecting the stability of the excitation coil resistance, the inductance of the excitation coil, the capacitance of the energy storage capacitor, the charging voltage and the ambient temperature are analyzed. Then, 2D ERM simulation model is set up and study the above parameters deviation and the change of environmental temperature on the repulsive force driving characteristics. In order to ensure that the ERM moves to 10mm in 2ms, and the time dispersion is less than ±0.2ms. The reasonable variation ranges of each parameter required for the stable action of the ERM and the appropriate working environment temperature are determined. Finally, the developed FMS prototype was tested for opening, temperature rise and consistency, and the test results were consistent with the simulation results.

Study on Characteristics of Radiated Electromagnetic Waves of Circuit Breakers

In order to study the new method of onsite detection of circuit breaker based on electromagnetic method, the characteristics of electromagnetic signal in the process of circuit breaker opening and closing were studied. The research results show that the electromagnetic wave will be radiated during opening and closing of the circuit breaker, and its frequency can reach 2GHz. The signal excited when the circuit breaker is closed is greater than the signal when the switch is opened, and the signal excited when the load is activated is greater than the signal when the switch is not loaded.

Current Status of Testing and Research on Circuit Breaker Mechanical Performance and Arc Extinction

The performance of the circuit breaker mainly includes mechanical performance and arc extinguishing performance. This paper reviews the current status of its detection methods. Research indicates that the dynamic characteristic instrument method can meet the needs of offline detection for the detection of mechanical properties, but it cannot be implemented with electricity. The traditional method for detecting the degree of contact ablation is the electrical life method, which determines the change in the degree of contact ablation of the high-voltage reactive switching switch by the weighted calculation of the number of breaking and the breaking current. This method can only reflect the deterioration of the contact ablation degree of the high-voltage reactive switching switch, but it cannot reflect the abrupt or abnormal contact ablation degree deterioration. It is necessary to carry out research on new technology for live detection of circuit breaker performance.

A Coupled-Inductor-Based Bidirectional Circuit Breaker for DC Microgrid

DC microgrids have attracted more and more attention with its universality, high efficiency, and potential application market. However, dc fault protection is still a challenge to the development of dc microgrids. In this article, a novel bidirectional dc solid-state circuit breaker based on coupled inductor is introduced. It can realize bidirectional energy flow and bidirectional isolation and interruption of short-circuit faults with fewer components. The working principle of the topology and the working process under different conditions are described, and some properties of the novel circuit breaker are explored, including minimum fault current ramp rate and load step analysis, which provide a reference for the selection of component parameters. Finally, the feasibility and performance of the novel bidirectional circuit breaker is evaluated by simulations and experiments.

Ultra-Low on-State Voltage IGCT for Solid-State DC Circuit Breaker With Single-Switching Attribute

The performance of solid-state dc circuit breaker (SS-DCCB) is mainly determined by the on -state feature of power device. In this article, an optimized low on -state voltage integrated gate-commutated thyristor (LO-IGCT) for SS-DCCB is developed. First, the impacts of device parameters, including base length, carrier lifetime, and emitter injection efficiencies, on on -state voltage are presented. The boundary conditions raised by blocking voltage and safe operation area (SOA) are analyzed. Based on that, a three-step blocking-SOA-emitter optimization routine is proposed. Then, the optimization methodology for doping profiles in different regions, especially in n -drift, n buffer, p + base, n + emitter, and p + emitter regions, is presented. The optimal values are derived with theoretical deduction or numerical calculation. After that, based the optimization result, samples of LO-IGCTs are fabricated and tested. The fabricated LO-IGCT sample shows a blocking voltage capability over 4500 V and an on -state voltage of 1.11 V at the current of 2000 A. The commercialized IGCT and IGBT optimized for high-frequency applications exhibits 1.23 and 1.85 times the on -state voltage under the same test configuration.

Operation Characteristics for the Superconducting Arc-Induction Type DC Circuit Breaker

The multi-terminal direct current network is expected to commercialize while carrying out projects related to DC power systems worldwide. Accordingly, it is necessary to develop a DC circuit breaker required for the DC power system. A DC circuit breaker should be developed to protect the DC power system and the consumer from the transient state on the line in any case. Currently, the use of power semiconductors increases the performance of DC circuit breakers. However, power semiconductors are expensive and suffer series of losses from frequent failures. Therefore, the DC circuit breaker must have a reliable, stable, and inexpensive structure. We proposed a new type of arc-induction type DC circuit breaker. It consists of a mechanical blocking contact, an induction needle and a superconducting magnet. It blows the arc with an induction needle using the Lorentz force according to the high magnetic field of the superconducting magnet. The arc-induction needle absorbs the arc and flows through the ground wire to the ground to extinguish the arc. We established this principle of arc induction as a mathematical model. In addition, the Maxwell program was used to secure data of electric and magnetic fields and apply them to mathematical models. The results obtained through numerical analysis were analyzed and compared. As a result, we confirmed that the magnitude of the force exerted on the electrons between the mechanical contacts with the superconducting magnets increased about 1.41 times and reasoned the arc-induction phenomenon out numerically.

Effective microgrid restructuring in the presence of high DG proliferation

Distributed generators bring in promising benefits as well as question the efficacious relaying operation of the conventional radial distribution systems on the penetration. Among different types of interface machines, synchronous generators upon increased penetration create major disruptions to the existing operation of relays and circuit breakers due to their high fault current capability. Hence, this work employs reconfiguration as a strategy to mitigate the protection issues imposed by a highly proliferated DG network. As restructuring also has the capability to create relay miscoordinations, a vigilant identification of optimal structure is carried out. 22.9% loss reduction, 24.3% reduction in the sustained interruption hours faced by an average consumer and 35.8% decrease in the maximum electricity price paid by the consumer at a load point are achieved for the practical 52-bus microgrid while attempting to reconfigure in view of addressing the protection challenges. 21.84% drop is observed in total size of fault current limiters as well. 33 and 69 bus benchmark systems transformed to a microgrid are also employed to validate the proposed reconfiguration strategy. New tie-line combinations are searched for each test system in a view to look for a superior structure giving out best results in the context of study.

A Newly Designed Diagnostic Method for Mechanical Faults of High-Voltage Circuit Breakers via SSAE and IELM

In general, vibration signals generated by the switching operation of a high-voltage circuit breaker (HVCB) contains important information to reflect its mechanical status. A method for mechanical fault diagnoses of an HVCB based on a semisupervised stacked autoencoder (SSAE) and an integrated extreme learning machine (IELM) is proposed in this study. First, the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is used to decompose the vibration signal to obtain the time–frequency energy matrix. Then, an SSAE model is applied to automatically extract the characteristic information from the energy matrix. As a result, two-level classifiers can be constructed. The first level is utilized to identify normal or abnormal states, and the second level is selected to identify various types of faults in the abnormal state. The classifiers of these levels are composed of binary IELM. The advantages of the proposed method are that it not only can automatically extract the high-recognition features from the time–frequency energy matrix of high dimension to complete the identification of the existing fault types in the training set but also can accurately identify the samples of unknown types of faults. Experimental results show that the proposed method can effectively diagnose mechanical faults of an HVCB, and the classification accuracy reaches 99.5%.

A Novel Methodology to Incorporate Circuit Breaker Active Failure in Reliability Evaluation of Electrical Distribution Networks

The random failure of components in a distribution network leads to power supply interruptions to electricity customers. Among different failure modes in the distribution network components, active failure is more frequent and requires the circuit breaker operations to isolate faulty segments. Active failure of a breaker causes the operation of a backup breaker, thus, exposing the larger segment of the network to outages. This paper proposes a new analytical methodology to identify breaker active failure events involving different order of contingencies. This methodology introduces an active breaker incidence (ABI) matrix to capture the active failure of breakers leading to load point failures. The ABI matrix is concatenated to the incidence matrix of the minimal path to form a new incidence matrix which reflects the information of all failure events including active failure of circuit breakers. These failure events are then utilized to evaluate the reliability indices. The proposed methodology is illustrated in a test distribution network. A study conducted on the IEEE Gold Book Standard Network shows that that the methodology effectively identifies and includes breaker failure events to evaluate the reliability performance, and that the proposed methodology can be utilized to make investment decisions in modern industrial distribution systems.

A study of multi-break HVDC gaseous circuit breaker performance by using black box arc model

The development of the renewable energy and the need of medium- and high-voltage direct current circuit breakers are the keys in the development of medium- and high-voltage transmission systems. It can be used in high-voltage systems as cascaded interrupters. In this paper, the cascaded interrupters of gaseous circuit breakers are simulated using black box arc models. The influences of the models parameters on the arc interruption time are studied. MATLAB/Simulink program is employed to carry out this study. It is concluded that the simulated results by employing black box arc models achieve a success in multi-break HVDC gaseous circuit breakers simulation. Employing BBAM models has proved more flexibility to study the effect of different controlled and uncontrolled parameters on the multi-break HVDCGCB arcing time. That has proved more flexibility to study the effect of different controlled and uncontrolled parameters on the arcing time. From the investigated forty cases done to check the Mayr’s model validity in the HVDC CD simulation, it is found that the values of P and $$ \tau $$ which give acceptable outputs are at $$ \tau = 10^{ - 6} \;{\text{s}} $$ , and P in range of 107–1011 W. The output of the case $$ \tau = 10^{ - 6} \;{\text{s}} $$ , P = 1010 W, which is introduced in the paper has proved that when $$ \tau $$ reached to 10−7 s, the MOV current rises and drops and thereafter rises and gradually decreases. This may lead to CB failure; Com parameters influences on the interrupter performance are investigated and proved good simulation of the gaseous circuit breaker interrupter. The commutation parameters affecting the interrupter performance are investigated. Investigation of the change in the fault arc resistance and the fault location on the DC line on the arcing time is presented. Finally the impact of the changing of fault resistance value on arcing time and the damping resistance influence on the transient recovery voltage is also investigated. Additionally, the initial transient interruption and the metal oxide varistor voltages are analyzed.

An Accurate Non-Pilot Scheme for Accelerated Trip of Distance Relay Zone-2 Faults

The delayed operation of distance relays zone-2 element for the faults at the end of the line is excessive. It reduces the fault clearing speed and therefore, is one of the main factors that can endanger power system stability. This paper proposes an impedance-based scheme for discrimination between the last 20% of the line length faults and the adjacent line faults, which are covered by the relay zone-2. The suggested non-pilot scheme uses a modified fault location formula for the accelerated zone-2 operation of distance relays. The negative- and zero-sequence components of local signals are utilized to calculate the accurate fault location after the remote circuit breaker (CB) operation. The proposed algorithm is independent of fault resistance, power flow direction, pre-fault condition, and it can clearly distinguish internal faults from the adjacent line faults. Simulation results show that the proposed method can identify the remote CB operation and thus can accelerate the tripping of zone-2 within a very short time for different fault locations, fault types, fault resistances, and load angles. Also, accurate fault location has been achieved under all simulation conditions.

Preventing cascading failure of electric power protection systems in nuclear power plant

Cascading failure is the main cause of large blackouts in electrical power systems; this paper analyzes a cascading failure in Hanbit nuclear power plant unit two (2) caused by a circuit breaker (CB) operation failure. This malfunction has been expanded to the loss of offsite power (LOOP). In this study, current practices are reviewed and then the methodologies of how to prevent cascading failures in protection power systems are introduced. An overview on the implementation of IEC61850 GOOSE messaging-based zone selective interlocking (ZSI) scheme as key solution is proposed. In consideration of ZSI blocking time, all influencing factors such as circuit breaker opening time, relay I/O response time and messages travelling time in the communication network should be taken into account. The purpose of this paper is to elaborate on the effect of cascading failure in NPP electrical power protection system and propose preventive actions for this failures. Finally, the expected advantages and challenges are elaborated.

Event-Based Simulation of a Decentralized Protection System Based on Secured GOOSE Messages

A new simulation library is developed on OMNeT++ to model faults in distribution systems. The proposed library makes it possible to calculate the status of lines and busbars from the point of view of a protection system, enabling the modeling of overcurrents, power outages and fault passage indicators. The library is applied to model a decentralized protection system based on the exchange of IEC 61850 Generic Object Oriented Substation Events (GOOSE) messages between intelligent electronic devices responsible for the operation of circuit breakers and disconnectors. The time needed to secure and transmit GOOSE messages over the Internet is characterized and included in the model. Several studies are carried out to analyze the effect of different parameters, such as GOOSE retransmission times and failure rates of switching devices and communication channels, on the performance of the protection system.

A survey on the magnet effect of circuit breakers in financial markets

Proponents of circuit breakers justify the practice citing its utility in placating stressed markets, persuading agents to reflect on available information, and to trade rationally. Opponents counter by calling it an infringement on laissez-faire price discovery process citing the lack of conclusive evidence of their effectiveness in market crises. After nearly three decades of theoretical and empirical scrutiny, this discord persists. Most of the empirical focus in this domain revolves around ex-post performance of circuit breakers in cooling off the market, interference in trading, volatility splattering, and delayed assimilation of information. A less explored hypothesis is a potential for traders to hasten trading plans fearing illiquidity or trading blockade. Thus, the existence of the circuit breaker alone can induce its tripping. Known formally as the magnet effect, this hypothesis remains less explored due–inter alia–to paucity of data and methodological limitations. Greater availability of high-frequency datasets in recent times, however, has spurred a growth in empirical works focusing purely on the magnet effect hypothesis. As this nascent sub-discipline in market microstructure grows, this paper undertakes one of the first formal surveys looking to consolidate theoretical and empirical works on magnet effect. Moreover, we discuss methodological challenges and analytic limitations which strain the credibility of academic research findings in this domain; particularly among regulators.

Snubber and Metal Oxide Varistor Optimization Design of Modular IGCT Switch for Overvoltage Suppression in Hybrid DC Circuit Breaker

The power electronic switches have great influences on the performance of the hybrid dc circuit breaker (DCCB). Recently, the integrated gate commutated thyristor (IGCT) is considered to be a suitable alternative full-control power device due to its high surge capability, high gate driver reliability, and low cost. Remarkably, high economic efficiency overvoltage suppression is important to the practical use of the IGCT switch. In this article, snubber and metal oxide varistor (MOV) optimization design for the purpose of reducing the passive components' cost is studied. Theoretical and mathematical analysis shows that the highest overvoltage precedes MOV's peak current. Then, the dynamic MOV model considering the response delay and steep front effect is built up. Next, an improved simulation circuit for calculating the highest overvoltage is established. The comparisons with experiment indicate the feasibility and accuracy of the simulation circuit. Based on the simulation results, the optimization design for overvoltage suppression is demonstrated and a cost performance promotion of 8.5% is obtained. Furthermore, the guidance of stray inductance for the structural design is also determined. In the end, a prototype for 10-kV DCCB is constructed and the tests of the IGCT switches verify the feasibility and validity of the overvoltage suppression design.

Ex-post effects of circuit breakers in crisis and calm markets

PurposeDespite regulatory claims of straitening volatility and preventing crashes, evidences on circuit breakers' ability to achieve so are nonconclusive. While previous scholars studies general performances of circuit breakers, the authors examine whether Malaysian price limits aggravate volatility, impede price discovery, and interfere with trading activities in both tranquil and stressful periods.Design/methodology/approachThe study uses a combination of parametric and nonparametric techniques consistent with Kim and Rhee (1997) to examine the major ex-post hypotheses in circuit breaker research.FindingsFor calm markets, the authors find significant success of upper limits in tempering volatility with low trading interference. Lower limits show mixed results. Conversely, in crisis markets limits fare poorly in nearly all aspects, particularly for lower limits.Practical implicationsRamifications of the paper's findings are discussed through highlighting the asymmetric nature of price limits' ex-post effects. The paper also contributes to regulatory debate surrounding the quest for an optimal price limit.Originality/valueThe paper is the first of its kind in documenting long-horizon evidence of ex-post effects of a wide-band price limit. Moreover, the paper is unique in its approach in bifurcating circuit breaker performance along the line of market stability periods.

Improved MVDC Breaker Operation by Active Fault Current Sharing (FCS) of Existing Power Converters for Shipboard Applications

In this article, an active fault current sharing (FCS) strategy is proposed to improve the dc circuit breaker (CB) operation in a breaker-based medium-voltage dc (MVdc) system. The peak turn-off current of CBs can be decreased by controlling the existing converters located in parallel with activated CBs to share the fault current. This reduction effect can be amplified from the systematic perspective since one single converter with the proposed FCS can benefit different CBs in various fault scenarios. The short-circuit fault scenarios of a shipboard breaker-based MVdc system are analyzed and the corresponding fault equivalent circuits, including power converters adjacent to CBs, are developed. The device stress of voltage-fed (VF) and current-fed (CF) converters applying the proposed active FCS strategies during short-circuit faults is derived and compared with those of passively shutdown counterparts. Finally, a downscaled experimental test bed was built to emulate a 6-kV/6-MW MVdc system fault scenarios. The experimental results are provided to verify the proposed FCS.

A DC Fault Protection Scheme for MMC-HVDC Grids Using New Directional Criterion

To meet the ultra-fast, selective, and reliable requirements of the DC fault protection, a protection scheme for modular multilevel converter based HVDC grids is proposed in this paper. The protection scheme is consisted of main protection, directional pilot protection, and faulty pole identification. The new fault directional criterion is achieved by employing the surge arriving time difference of line-mode backward traveling wave and line-mode forward traveling wave. This criterion is valid even when the fault current limiting reactors (FCLRs) are installed at the converter side of DC bus. The main protection without communication and complex computation relies on co-operation of the derivative of line-mode forward traveling wave and the directional criterion. The directional pilot protection by comparing the double end directional criteria can be used as a backup protection. The accumulation of zero-mode component is adopted to discriminate the faulty pole. Simulations have demonstrated that the proposed scheme is capable of identifying various types of faults with different fault resistances at different positions. The robustness analysis shows that the protection scheme presented is not sensitive to the FCLR size, noise environment, sampling frequency, and the operation of hybrid DC circuit breakers.

Failures of Equipment Operating Under Normal Conditions: Arc-Flash Events can Happen during Normal Operation

Informational Note No. 1 for the definition of arc-flash hazard in National Fire Protection Association (NFPA) Standard 70E-2015 states, Under normal operating conditions, enclosed energized equipment that has been properly installed and maintained is not likely to pose an arc-flash hazard. Table 130.7(C)(15)(A)(a) of the standard instructs that arc-flash personal protective equipment (PPE) is not required for normal operation of a circuit breaker, switch, contactor, or starter if the equipment is properly installed, properly maintained, equipment doors and covers are closed and secured, and there is no evidence of impending failure. This article reviews three electrical equipment failures during substation circuit breaker operations where if personnel had followed the guidelines just described, they could have been seriously injured during these failures due to the arc-flash energy released at the time of the fault.

A study on thermal‐interrupting performance improvement of SF6 gas circuit breaker by promotion of nozzle ablation

In this paper, ablation polymer was studied to improve the thermal interrupting performance of an SF6 gas circuit breaker. One kind of polymer was used as the ablation polymer on the basis of the specific constraint conditions for SF6 gas circuit breakers, such as not including hydrogen, and its ablation characteristics were investigated. Furthermore, the dominant factor of that polymer ablation was discussed by comparing ablated mass characteristics between the ablation polymer and polytetrafluoroethylene, which is widely used as the nozzle material of an SF6 gas circuit breaker. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.