Breaker Technology Research Articles

Integrated Experimental and Simulation Investigation of Breakdown Voltage Characteristics Across Electrode Configurations in SF6 Circuit Breakers

This study investigates the breakdown voltage characteristics in sulfur hexafluoride (SF6) circuit breakers, employing a novel approach that integrates both experimental investigations and finite element simulations. Utilizing a sphere-sphere electrode configuration, we meticulously measured the relationship between breakdown voltage and electrode gap distances ranging from 1 cm to 4.5 cm. Subsequent simulations, conducted using COMSOL Multiphysics, mirrored the experimental setup to validate the model’s accuracy through a comparison of the breakdown voltage-electrode gap distance curves. The simulation results not only aligned closely with the experimental data but also allowed the extraction of detailed electric field strength, electric potential contours, and electric current flow curves at the breakdown voltage for gap distances extending from 1 to 4.5 cm. Extending the analysis, the study explored the electric field and potential distribution at a constant voltage of 72.5 kV for gap distances between 1 to 10 cm, identifying the maximum electric field strength. A comprehensive comparison of five different electrode configurations (sphere-sphere, sphere-rod, sphere-plane, rod-plane, rod-rod) at 72.5 kV and a gap distance of 1.84 cm underscored the significant influence of electrode geometry on the breakdown process. Moreover, the research contrasts the breakdown voltage in SF6 with that in air, emphasizing SF6’s superior insulating properties. This investigation not only elucidates the intricate dynamics of electrical breakdown in SF6 circuit breakers but also contributes valuable insights into the optimal electrode configurations and the potential for alternative insulating gases, steering future advancements in high-voltage circuit breaker technology.

Systematic Review and Meta-analysis of DC Circuit Breaker Technologies for Sustainable DC Grids

Systematic Review and Meta-analysis of DC Circuit Breaker Technologies for Sustainable DC Grids

Extending the Life of Low Voltage Adjustable Speed Drives: The Newest Technology to Eliminate Risk

A fundamental aspect of low voltage adjustable speed drives’ (LV ASDs’) overcurrent protection is the elimination of harmful input power anomalies that could significantly damage the sensitive electronics in and around the ASD. This article provides an overview of the newest LV solid-state circuit breaker (SSCB) technology and how petroleum and chemical industry users can take advantage of its ability in eliminating almost all the electromechanical stresses applied at the input to any LV ASD when protected with traditional circuit breakers or high-speed protective fuses. This higher level of protection comes through the use of SSCB technologies that provide the lowest let-through energy level of any overcurrent protective device available today. At the same time, these devices eliminate risk by reducing harmful arc flash incident energy to near-negligible levels while requiring no maintenance.

Applicability Analysis of a Multi-Filar Meander R-SFCL and an RSC-DCCB in an MMC-MTDC Grid

modular multilevel converters (MMC)-based high voltage direct current (HVDC) topology is an effective solution to solve the power transmission demand between countries. However, the initial fault current can rise to several tens of kA within a few ms by capacitor discharge during a fault. This fault current can permanently damage the converter components and cables. Therefore, to increase the stability of the system, the protection of the DC system is very important. DC system protection methods include circuit breaker technologies and current limiting technologies. We have selected a circuit breaker with combined resonant current source (RCS) and a resistive superconducting fault current limiter (SFCL) as protection methods for the DC system. The RSC-DC circuit breaker has no conduction power losses by on-state voltage drop. Therefore, it can provide stable interruption compared to a solid-state DC circuit breaker. Since the resistive SFCL has a very fast response time, it can effectively limit the rapidly rising initial fault current. We wound the superconducting tape by the multi-filar meander method. This method can increase the length of the superconducting tape used and speed up the bubble diffusion during quenching. We modeled an MMC-HVDC grid, resistive SFCL, and RCS DC circuit breaker using PSCAD/EMTDC. In this paper, the interrupting and current limiting characteristics are discussed when the resistive SFCL and the RCS-DC circuit breaker proposed by us are connected to the MMC-based MTDC grid. In the simulation, the current limiting factor of resistive SFCL was up to about 58%. In addition, the combination of resistive SFCL and RCS-DC circuit breaker can shorten the interruption time when the fault occurs.

An Ultralow-Loss Fault-Current-Limiting Z-Source LVDC Circuit Breaker Using Cryogenic Power Electronics

Room-temperature power electronics based DC circuit breakers and fault current limiters face two major challenges: high conduction loss, and time-delayed response. This letter presents a novel circuitry, for the first time (based on literature studies), to combine cryogenic power electronics (CPE), together with the superconducting Z-source DC circuit breaker technology. The design, fabrication and tests of the new device were carried out, and 3 advantages were proved: (1) The actual overall system loss (including cryogenic issues) reduced by 62.1% in the 2 kW case study; (2) The no-delay automatic fault current limiting technology provided a sudden protective resistor ∼0.1 Ω to suppress the fault below 200 A, and meanwhile stabilized the bus voltage; (3) The CPE-based breaker achieved both the active device isolation and passive fault isolation within 60 μs.

Study on Short-circuit current interruption characteristics of Double-break fast vacuum circuit breaker within the minimum arcing time

It is significant for circuit breakers to expel a short-circuit fault in a short time for the new power grid with high proportional photovoltaic or wind power plants to achieve high transient operating stability. Compared with a traditional circuit breaker, a fast vacuum circuit breaker (FVCB), operated by an electromagnetic repulsion actuator, has an extremely shorter opening time and lower deviation in their opening times. This potentially contributes the FVCBs to interrupting a short-circuit fault current in the first half-wave when introducing a controlled switching technology. Meanwhile, it is beneficial to improve the short-circuit current breaking capacity of the FVCBs by adopting series-connected double-break circuit breaker technologies. This paper aims to explore short-circuit current interruption characteristics of a double-break FVCB within the minimum arcing time. We performed a series of short-circuit current interruption tests in a Weil synthetic test circuit. Two series-connected FVCBs and independent single-break FVCBs were used. Three different kinds of opening velocities were adopted for each of the FVCBs. Results showed that the increase in opening velocity resulted in both a decrease in the minimum arcing time and the critical arc extinguishing contact gap, whether for the single-break or the double-break interruption tests. The ratio of the shared voltage on each of the series-connected FVCBs was about 54 (for the break on the high-voltage side) and 9 (for the break on the low-voltage side). Taking the break with a shorter opening time as a break in the high-voltage side could reduce the minimum arcing time and the critical arc extinguishing contact gap. At the same opening velocity, the sum of the critical arc extinguishing contact gap of the two breaks in double-break interruption tests was significantly higher than twice the critical arc extinguishing contact gap in the single-break interruption tests. This could be caused by the fact that in double-break interruption tests, after the breakdown of one break, even if the break restored insulation, could not share the transient recovery voltage (TRV) before the break broke down. In addition, the sudden drop of TRV without breakdown occurred for the break on the high-voltage side might correlate with the micro-discharge of the vacuum gap. The interaction of the charged particles with the electrode surface would be responsible for the formation and evolution of the micro-discharge in some successful interruption cases.

A High-Efficiency Protection Circuit Integrating Semi-Soft Switching and Voltage Limiting Functions for Solid-State Switch Applications

Despite the high performance of high-voltage direct current circuit breaker (CB) technology, its high cost restricts its further development. Thus, this article proposes a high-efficiency protection circuit for solid-state switches (SSs) that integrates semisoft switching and voltage limiting functions. The protection circuit also does not resonate with the system inductance which in turn does not affect the reclosing operation of the CB. The novel SS scheme reduces the cost and simplifies the layout of the SS. The special constraints for the parameter design of power electronics, gaps, and metal oxide varistors (MOVs) are proposed in this article for the first time, and a parameters design method that solves the transient power shock and voltage spike problems during the large current breaking process under multiple constraints is formed. Finally, an SS prototype is developed to verify the feasibility and the strong surge and turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> ability of the novel SS and to test the robustness of the series-connected gapped-MOV circuits.

Modular Bidirectional Solid-State DC Circuit Breaker for Next-Generation Electric Aircrafts

The design of electric power systems (EPSs) for the aviation industry has become a major research area to reduce the global annual CO2 emission caused by the transportation sector. DC power distribution is envisaged to meet the high load demand of more-electric and all-electric aircraft power architectures. Nonetheless, the development of dc distribution is significantly impeded by the challenges associated with dc system protection. Aircraft EPS demands high speed and high current protection. Among various dc circuit breaker (DCCB) technologies, solid-state dc circuit breakers (SSCBs) operate at higher speeds. To make them withstand high current ratings, modular structured DCCBs with the highest power density, reliability, and bidirectional fault interruption capability are presented in this article. The existing DCCBs fail to comply with the design constraints such as faster response, high current breaking, and compact design. This article proposes a coupled inductor-based modular bidirectional SSCB that employs the magnetic coupling principle for counter-current commutation of thyristors. The proposed modular SSCB exhibits a fast fault interruption time of approximately 200 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> . The analysis, design, and experimental validation of the proposed SSCB are presented in detail. Each module in the prototype is designed for a system rating of 270 V/15 A. The performance of this SSCB for single- and two-module operations is experimentally verified for a 270-V/20-A dc system.

Biodegradation of Polymers Used in Oil and Gas Operations: Towards Enzyme Biotechnology Development and Field Application.

Linear and crosslinked polymers are commonly used in the oil and gas industry. Guar-derived polymers have been extensively utilized in hydraulic fracturing processes, and recently polyacrylamide and cellulose-based polymers have also found utility. As these polymers are used during various phases of the hydraulic fracturing process, they can accumulate at formation fracture faces, resulting in undesired filter cakes that impede oil and gas recovery. Although acids and chemical oxidizers are often added in the fracturing fluids to degrade or ‘break’ polymer filter cakes, the constant use of these chemicals can be hazardous and can result in formation damage and corrosion of infrastructure. Alternately, the use of enzymes is an attractive and environmentally friendly technology that can be used to treat polymer accumulations. While guar-linkage-specific enzyme breakers isolated from bacteria have been shown to successfully cleave guar-based polymers and decrease their molecular weight and viscosity at reservoir conditions, new enzymes that target a broader range of polymers currently used in hydraulic fracturing operations still require research and development for effective application. This review article describes the current state-of-knowledge on the mechanisms and enzymes involved in biodegradation of guar gum, polyacrylamide (and hydrolyzed polyacrylamide), and carboxymethyl cellulose polymers. In addition, advantages and challenges in the development and application of enzyme breaker technologies are discussed.

A Contribution to the Development of High-Voltage dc Circuit Breaker Technologies: A Review of New Considerations

To promote the integration of renewable energy resources into modern energy systems, high-voltage dc (HVdc) and circuit breaker (CB) technologies have become critical to achieving secure and efficient energy transmission. This article reviews the technical development of the related areas, compares diverse breaker concepts and topologies, investigates possible coordination and testing solutions, and points out the remaining challenges as well as future needs. The time-domain simulation and comparative analysis are adopted in this article to analyze and compare the performances of different HVdc CBs. By making use of different selectivity levels of multiterminal HVdc (MTdc) grids, the suitable planning and placement of HVdc CBs can be conducted. Furthermore, by providing insights into the performance of HVdc CBs, the work presented in this article can serve as a useful asset for the upcoming standardization and industrial application process of HVdc grid and CB design and testing.

INSTALLED BASE SAFETY UPGRADE AT POWER GENERATION STATION

The study case power-generation plant comprises four steam generation units, commissioned in the 1990&apos;s, it is one of the largest in Italy and one of major in Europe, contributing to base load demand to the country south region. Age and limited availability of replacement parts for original medium voltage air magnetic circuit breaker, now in obsolete life cycle phase, is an operation concern on such mission critical equipment, as well as racking operation procedure on original 50kA rated installation not internal arc classified. The owning Utility strategy drives energy transition towards an increasingly sustainable model and the plant electrical installed base modernization, focusing on efficiency, health and safety as the three key elements. Innovative retrofit solutions have been designed and fully type tested to enable original installed base modernization with latest circuit breaker technology, providing withdrawable motorized execution for safety and easy maintenance. The benefits in terms of safety upgrade and installation are described. Furthermore, operation benefits such as standardization of spare parts, replacement of mechanical to electrical signalling and easiness of racking procedure is discussed.

HVdc application: A valuable source for education and reference [Book Review

This book provides a valuable update to the first edition of High Voltage Direct Current Transmission. Jovcic is a professor at the University of Aberdeen, Aberdeen, United Kingdom, where he has been since 2004. He has a Ph.D. from the University of Auckland, New Zealand. Jovcic is a Fellow of IEEE. His research interests include high-voltage (HV) dc, dc grids, and control systems. High Voltage Direct Current Transmission provides comprehensive coverage of HVdc transmission and in-depth knowledge in key areas for the application of HVdc: power electronics, control engineering, and ac/dc power transmission systems analysis. The application of HVdc transmission is experiencing rapid growth and leading to new technology developments. This second edition provides new material to cover these developments with emphasis on developments going into new field installations. The book is divided into three major sections. The first section covers line commutated converter (LCC) HVdc. This edition includes system topologies and control schemes and adds a discussion of dc grid master controls. This section includes a discussion of dc/ dc converters for connecting systems at different voltage levels and HVdc circuit breaker technologies. The author provides many examples throughout the book. This book is suitable for graduate-level power engineering and power electronics students. It also serves as a valuable reference for researchers in academia and engineers in the industry.

HVdc Circuit Breakers: Prospects and Challenges

The integration of offshore wind farms has revitalized the interest in multi–terminal high voltage direct current (M–HVdc) transmission grids. HVdc breakers’ importance has increased as M–HVdc grids are now a commercial truth. Several HVdc circuit breaker technologies have been developed, published, and appeared as prototypes for HVdc networks. This paper summarizes the HVdc breaker technologies from the last two decades, distributed mainly in literature. A comparison of various state–of–the–art HVdc breakers is presented. Further, areas are identified where further research and development are required. The goal is to provide primary challenges and prospects in the HVdc breaker field.

Study on the flexible arc elimination method for grounding fault of distribution network based on single-phase cascade H bridge

All 10kV distribution network systems in China adopt non-effective grounding. With the expansion of distribution network scale, the earth fault current and the harmonic content increases. The earth fault arc difficult extinguish by itself. The traditional circuit breaker technology for failover to the substation may cause the potential to rise in the station. In this paper, A voltage arc extinction method for the combination of single-phase cascade H-bridge converter and vacuum circuit breaker is proposed. Three single-phase vacuum circuit breakers are respectively connected to A, B and C phases. When the fault occurs, the closed corresponding circuit breaker is connected to the ground fault for transfer. A double closed-loop control system is constructed to track the ground fault current in real time based on the deadbeat control method, so as to realize the full compensation of ground fault current and eliminate the ground potential rise. Through RT-Lab simulation platform, a 10kV distribution network model was built. The arc extinction method proposed in this paper was simulated and analyzed different resistance grounding. It was verified that it could effectively suppress arc light grounding fault and solve the problem that the traditional failover device could not flexibly control zero-sequence current.

A Zero Crossing Hybrid Bidirectional DC Circuit Breaker for HVDC Transmission Systems

With the increasing demand for renewable energy power generation systems, high-power DC transmission technology is drawing considerable attention. As a result, stability issues associated with high power DC transmission have been highlighted. One of these problems is the fault current that appears when a fault occurs in the transmission line. If the fault current flows in the transmission line, it has a serious adverse effect on the rectifier stage, inverter stage and transmission line load. This makes the transmission technology less reliable and can lead to secondary problems such as fire. Therefore, fault current must be managed safely. DC circuit breaker technology has been proposed to solve this problem. However, conventional technologies generally do not take into account the effects of fault current on the transmission line, and their efficiency is relatively low. The purpose of this study is to introduce an improved DC circuit breaker that uses a blocking inductor to minimize the effect of fault current on the transmission line. It also uses a ground inductor to efficiently manage the LC resonant current and dissipate residual current. DC circuit breakers minimize adverse effects on external elements and transmission lines because the use of elements placed on each is distinct. All of these processes are precisely verified by conducting simulation under 200 MVA (±100 kV) conditions based on the VSC-based HVDC transmission link. In addition, the mechanism was explained by analyzing the simulation results to increase the reliability of the circuit in this paper.

Backup Protection Algorithm for Failures in Modular DC Circuit Breakers

HVDC grid protection with adequate speed and reliability is required to minimise the impact of DC faults. In particular, fast breaker failure backup protection algorithms are needed to meet the expected reliability requirements of HVDC grids. In this paper, existing breaker failure backup protection algorithms are shown inadequate to detect partial failures like a single module failure of breakers with a modular structure. This paper proposes a backup protection algorithm which rapidly detects a DC breaker failure based on estimating the counter-voltage created by the energy absorption branch during an interruption. The performance of the proposed algorithm is evaluated using a four-terminal test network with both hybrid and mechanical DC breaker technologies. The simulation results show that the proposed algorithm is able to quickly detect both complete and partial failures of the two breaker technologies even considering measurement errors, noise and ageing of the energy absorption components.

High‐voltage direct current fault current interruption: A technology review

This review paper describes fault current interruption principles and various high-voltage direct currrent (HVDC) circuit breaker technologies. First, fundamentals of HVDC fault current interruption and a generic set of requirements of HVDC circuit breakers are presented. The critical parameters during fault current interruption are assessed using a simplified mathematical model. Then, the state-of-the-art of HVDC circuit breaker technologies and their application in actual HVDC multi-terminal projects is highlighted. Several sub-components of HVDC circuit breakers are standard components used in a non-standard application and, hence, have to face non-standard stresses. All of today's HVDC circuit breaker technologies consist of mechanical switching devices and metal-oxide surge arresters, which are used in an unconventional way. A critical analysis of these stresses compared to the stresses in a conventional application is provided. Recommendations on testing supported with examples of actual full-power ‘complete’ demonstration of HVDC circuit breakers up to 350 kV/20 kA are discussed. Finally, the actual status of standardisation activities is presented.

Application of a novel approach of resistive‐type superconducting fault current limiter with a fast protection system in multi‐terminal direct current network

The key obstacle in the realization of Multi-terminal HVDC (MTDC) grids is the lack of existing commercial protection that a device can withstand the DC fault. Although different HVDC circuit breaker technologies have been investigated and demonstrators tested by manufacturers, the innovation of such devices to ensure a reliable protection system has not been proven yet due to the maximum braking capability limitation especially in MTDC grids. To this, a combination of Superconducting Fault Current Limiter (SFCL) technology with a fast DC circuit breaker could bring a solution to this bottleneck. In this work, a new application of an accurate model of resistive-type SFCL (rSFCL) considering both the electrical and thermal behaviors is proposed to work together with a proactive hybrid DC circuit breaker (PHCB) to fulfill the whole system protection. The viability of the proposed approach is verified under a worst DC fault case-scenario that imposed in a five-terminal MTDC meshed grid. The numerical analysis and simulations are carried out using (EMTP-rv®) software, while the obtained results show how significantly the proposed rSFCL can reduce the fault current and enhance the breaking capability. Also, a positive interaction has been observed between the rSFCL and PHCB in terms of design sizing and operation performance.

A Review of Solid-State Circuit Breakers

Although conventional electromechanical circuit breakers have a proven record as effective and reliable devices for circuit protection, emerging power distribution technologies and architectures, such as dc microgrids, require improved interruption performance characteristics (e.g., faster switching speed). The need for faster switching operation, in combination with the latest developments of advanced power semiconductor technologies, has spurred an increase in the research and development in the area of solid-state circuit breakers. This article provides a comprehensive review of various solid-state circuit breaker technologies that have been reported in the literature during recent years. First, we categorize solid-state circuit breakers based on key features and subsystems, including power semiconductor devices, main circuit topologies, voltage clamping methods, gate drivers, fault detection methods, and commutation methods for power semiconductor devices. Second, we discuss the various challenges associated with the design of solid-state circuit breakers from the perspective of generic applications and provide a comparison of several solid-state breaker technologies based on key metrics. Finally, we provide a useful framework and point of reference for future development of solid-state circuit breakers for many emerging power distribution applications.

HVDC Circuit Breakers–A Review

HVDC circuit breakers are of increasing importance, as multi-terminal high voltage DC (HVDC) transmission becomes a commercial reality. Multiple HVDC breaker technologies have been developed, and are starting to appear as proof-of-concept installations on real networks. Information about them is however distributed widely in the literature. This article describes the underlying challenges, the leading candidate solutions, and discusses the requirements and construction of the component sub-assemblies. Its goal is to provide a comprehensive overview of the field.