Electrical Faults Research Articles

Time correction to eliminate structural ambiguity on velocity anomaly in the upper cibulakan formation of ITEUNG field, northern West Java basin

Converting seismic data or structural maps from time to depth domain is very important in the stage of oil and gas exploration. Interpretation in time domain often produce inaccurate interpretation especially in zones under high velocity such as sub-salt or sub-carbonate. Under this zone, there are pull up velocity anomalies or pseudo-anticline. Otherwise in zones under low velocity such as water bottoms with sharp or fluctuating slopes (canyons), loose material overburden or rapid sedimentation, under detached electric normal faults and shale flaps, there are push down velocity anomaly or pseudo-syncline. The study area is in the Main and Massive Formation of ITEUNG Field, Northern West Java Basin where is proven to have petroleum potential. In the study area there are pull-up velocity anomaly or pseudo-anticline even though in reality they are just flat or even syncline due to the location in the zone under high velocity. This study aims to correct velocity anomaly by doing time correction and convert the time domain structure map into depth domain structure map with the time-depth curve method to eliminate structural ambiguity on velocity anomaly. The result shows that the map is obtained in the form of a depth domain structure map which is more accurate than the time domain structure map. Depth structure map make the interpretation more accurate because the structures in depth structure map is more similar to the original sovereignty after correlating with well data. In this present study shows that pull up velocity anomaly can be avoided so that interpretation can be done more accurately.

Quantitative fire risk assessment for an office building

In Romania, the risk of a fire occurring within a building is determined in a very conservative manner, as a function of the building occupancy type and the thermal load contained within each enclosure. The result is a qualitative expression of low, moderate or high fire risk. On the other hand, the fire is a serious hazard which has to be taken into account within the decision-making process by any organisation for the elaboration of their risk assessments and the risk management strategies. Nevertheless, the one carrying out a fire risk assessment has a various range of methods and techniques to apply, [1, 2] since the legislation does not specifically require a certain approach. This article is an example study of the application of Bayesian statistics to determine the probability of a fire occurring within an office building, due to an electrical fault.

Inspection of Residential Electrical Installations in Bayelsa State: A Review

The importance of initial verification and the need for periodic inspection and testing of the electrical installation of residential buildings cannot be overemphasized. Fire outbreak in residential buildings is very frequent in Bayelsa State and mostly attributed to electrical fault. The initial verification and periodic inspection and testing are unavoidable electrical procedures for the continuous safe use of any electrical installation. In this paper, a safe working procedure for periodic inspection is presented. The use of the schedule of circuit details, and the electrical danger notification (EDN) form is also presented. The periodic inspection and testing of the electrical installation in residential premises would definitely minimise the frequently witnessed electrical fire in residential buildings in Bayelsa State, and consequently guaranty the safety of both the building and the occupants of the property.

태양광 발전 시스템에서 MPPT 특성 기반의 전기적 고장 진단 기법의 적용 및 검증

This paper proposed an algorithm that can detect failures occurring in electrical fault while continuously performing MPPT in general solar power generation systems. The MPPT characteristics that appear in each situation were analyzed, and the characteristics of MPPT that appeared in electrical fault were analyzed and formulated. As a result, it is possible to judge whether the solar panel is normal, partial shade, or electrical fault, and verified through simulation. The hardware to which the proposed algorithm is applied detects electrical fault well and verifies its reliability. If the proposed algorithm is applied to the solar power generation system, it is judged that economic and social losses caused by fire can be reduced.

Selective Shut-off Strategy in Distributed Battery Systems

Rapid development in electric mobility raise distance anxiety. Thus, high ca-pacity systems with high efficiency are offered as a solution. However, the ca-pacity of the system is limited by the available space in the vehicle. To outcome this problem, the parallel distributed battery system is presented especially for heavy-duty vehicles like buses and trucks. Having a parallel distributed structure brings the necessity of providing a safety strategy not only for the single pack but also for the whole system. Every single pack has al-ready its fault protection system. Whenever an electrical fault occurs in the pack, it is cleared by either a contactor or a fuse. Thus, the pack becomes out of order, therefore, the vehicle cannot continue its operation and must be trailered. By utilizing a parallel dis-tributed battery system, vehicle continuity can be provided even after an electri-cal fault with a selective shut-off strategy. The presented strategy in this paper, not only provides vehicle continuity but also ensures additional safety on the system.

Detection of simultaneous mechanical faults in 6‐kV pumping induction motors using combined MCSA and stray flux methods

The popularity of stray and air-gap flux monitoring methods is increasing. This trend is justified by several advantages of such methods over the stator current monitoring that has been demonstrated for electrical fault detection in the induction and synchronous machines. However, the use of the magnetic flux for mechanical faults detections has not drawn this much attention, while in industry, the vibration analysis continues to be popular. This study comes to bridge this gap via the detection of mechanical faults of 6-kV induction motors in a pumping station. The diagnostic procedure mainly involves the stator current and stray flux monitoring, and harmonic index analysis. The localisation of the fault has been made possible via oscillometer readings. It will be shown that mechanical faults have a very different impact on the stator current and the flux signals, while the flux is not sensitive to the bearing fault mechanisms.

Application of Solar Energy Technology in Green Healthcare Camps for Fighting COVID-19 Outbreak in Saudi Arabia

The healthcare facilities sector is an energy-intensive organization especially at a time of spreading dangerous infectious viruses, such as new Coronavirus, or what is known as COVID-19. Recently, many countries have opened several mobile field quarantine hospitals provided with the required technical equipment to prevent the COVID-19 outbreak in these countries. Unfortunately, most of these healthcare camps are lacking in the application of the necessary sustainability principles and health standards to become green healthcare facilities. Solar energy can be used for various purposes in green healthcare facilities, such as power generation and other sterilized applications. Therefore, in the present paper, a new design for the mobile, quick built, and solar-powered green healthcare camp, in safe and effective 24 hours a day services, is introduced. The proposed green healthcare camp is built using modern building technologies for rapid constructions, in which the building design is proposed to incorporate the photovoltaic power generation consideration. Photovoltaic systems are designed according to the loads required for the operation of the designed model of the green healthcare camp. Moreover, the total cost of a solar-powered green healthcare camp is estimated according to local conditions and standards in Saudi Arabia. The practical recommendations are presented with the designed photovoltaic system to attain the overcurrent and overvoltage protection. The photovoltaic designed system is proposed under the condition of ascertaining the service continuity of the photovoltaic power system during the electric faults in the photovoltaic strings. This is achieved by incorporating series diodes at the terminals of each photovoltaic string. The performance of a 50-kW PV system simulated using Matlab/Simulink is evaluated for the fault disturbance to enhance the service continuity.

Non-invasive electric arc fault detection based on sliding approximate entropy

In recent years, electrical fires have occurred frequently and have become the first cause of various fires. Among them, the electric arc is one of the important causes of electrical fires. In this paper, the research on non-invasive electric arc fault detection is carried out for low-voltage users, which can discover and detect the electric arc only by analysing the aggregated current measurements from outdoors. In order to achieve this goal, firstly, the abrupt change of the current mode is discovered and detected with sliding window from the total load current signal based on the approximate entropy. Then the current signature samples are extracted around the abrupt change. Finally, according to the pre-set electric arc signature classifier, it is judged whether the abrupt change is caused by the electric arc fault. In addition, under laboratory conditions, an electric arc simulation experiment is carried out for common appliances of actual low-voltage users. The results show the effectiveness of the proposed non-invasive electric arc fault detection method based on approximate entropy.

Methodology for improvement protection systems performance associated to overhead lines

Power systems are permanently with failures risk, caused by electrical faults, human mistakes, harmonic component, flickers, among others. At the operational level, the impact of the incorrect operations of the Protection Systems in faults clearing has been documented, different studies cases of electrical failures not detected or not desired in a timely manner, they have led to the disconnection of the load of entire regions and even the total collapse of an electrical system. The foregoing is evident that the adequate selection of protection systems favors the reliable and safety operation of the grid. This paper introduces a novel methodology for the selection of protection systems for transmission lines, in the Peruvian National Interconnected Electric System. This methodology was structured for the revision of regulatory parameters related to the characteristics and performance of the protection systems and the technical aspects such as the redundancy of the protection system, the SIR estimation (source impedance ratio) and critical fault clearance times. Finally, the methodology studied in the Expansion Plan for Peru for the years 2019-2028, by means of electrical analysis, which allowed determining the way to have the characteristics of the protection systems of the new national grid expansion projects.

The Effect of Long Term Hygrothermal Aging by Immersion on Carbon/Epoxy Composites Exposed to the Heat Sources for Naval and Marine Applications

Fiber-Reinforced Polymer (FRP) composites have many advantages over conventional materials in terms of high strength-to-weight and stiffness-to-weight ratios, design flexibility and enhanced service life. Due to these advantages, FRP composites are used in many different fields such as Construction, Electric/power generation, Marine, Corrosion/infrastructure, transportation and so on. Most researches of FRP composites were focused on the applications used in ground field. However, in Navy, marine composite materials are increasingly being used in diverse applications: Submarine, Autonomous Underwater vehicle, Unmanned Surface vehicle and Payloads in Naval vessel. It is known that polymer composites are very sensitive and are friendly to water or moisture in any forms. Moisture in polymer composites often causes degradation by swelling and hydrolysis. Especially, if polymer composites will be immersed in water and seawater, faster degradation can be caused by water uptake than any other moisture environments. While general investigations regarding water uptake are concentrated on the composite materials cured in ambient temperature, the immersion effects of polymer composites exposed to elevated temperatures were studied because underwater applications of composite materials can be exposed to the various heat sources. For example, fires on naval vessels and underwater vehicles can be started by any number of causes such as electrical faults and ignition of flammable gases or liquids. Accordingly, immersion effects must be studied on marine composite materials exposed to various temperatures in order to evaluate service life in an underwater environment. This study investigated the water uptake, diffusion coefficient, and Short beam shear (SBS) for Interlaminar Shear Strength(ILSS), delamination between fiber and resin using test specimens exposed to the elevated temperatures. The specimens were immersed for a definite period of time (~one and a half years) in seawater and deionized water (DI water) to compare both degradation mechanisms.

Application of optical sensor array in partial discharge signal location of GIS/GIL

The optical sensor array inside the high-voltage equipment can effectively realize the on-line measurement of the high-voltage switch operation state, significantly improve the efficiency and accuracy of SF6 Electrical equipment fault diagnosis, and effectively guarantee the safety and reliability of equipment operation. Firstly, the structure and performance of the micro optical sensor are analyzed, and the system model and data processing unit of the optical sensor array are given. Furthermore, the influence characteristics of single sensor and array sensor Gaussian noise on signal are given, and the noise elimination strategy of observation signal based on Kalman filter is given. The results show that: the optical sensor has a good focusing ability for the optical signal, the light of the sensor array is reflected and propagated many times in the GIS/GIL of the high voltage switch-gear, and the internal partial discharge signal is located more accurately. The research results of this paper can provide important technical support for the GIS/GIL fault monitoring and early warning of the gas insulated electrical equipment on the transmission line.

An overview of various faults detection methods in synchronous generators

Synchronous generator (SG) plays a vital and critical role in the power system by supplying electric power to consumers. Various faults in SGs can cause some catastrophic events such as power disruption or blackout. These faults can be classified into two electrical and mechanical faults. Short circuit in stator windings and field winding are electrical fault while bearing, static/dynamic eccentricity, and broken damper bars faults are mechanical one. Unlike the induction machines, there are no much researches in SGs condition monitoring owing to its complex behaviour against the faults. Herein, the SG modelling approaches are presented briefly to elaborate shortcoming and challenging issues in the modelling, and then a comprehensive review of various electrical and mechanical fault detection methods is presented.

Quantifying the Window of Uncertainty for SSTDR Measurements of a Photovoltaic System

Spread spectrum time domain reflectometry (SSTDR) is a non-intrusive method for electrical fault detection and localization that enables continuous monitoring of live electrical systems. Electrical faults create changes in impedance that create subsequent changes in the SSTDR reflection response. These changes in reflection response can be detected only if the changes are outside the window of uncertainty of the SSTDR measurement. In this paper, we establish a method of determining this window of uncertainty and the associated minimum-detectable change in impedance for SSTDR measurements. We demonstrate this for a photovoltaic (PV) systems, although the methods could be similarly applied to other applications. We assess the variability in SSTDR measurements caused by changes in the PV system that are representative of normal maintenance actions such as disconnecting/reconnecting a connector and completely breaking-down/setting-up the entire system. We evaluate how this variability translates to a minimum-detectable change in impedance and how that relates to common faults in PV systems (arc and ground faults, shading, damaged cells, and aging). We also describe methods of increasing SSTDR fidelity to accurately extract minor changes in impedance and therefore, detect small-magnitude electrical faults.

Thermodynamic Analysis of Explosive Events in Manholes and Electrical Vaults

A computer code is used to simulate the conditions that exist during a manhole event consisting of an electrical fault and a gas explosion. When energy is generated within the structure, pressures can reach levels sufficient to propel the cover from its frame. The code quantifies the effects of the event and provides guidelines for the design of safety devices that can minimize the potential danger of the event. Differences between chemically-driven and electrically-driven events are shown to require different design criteria for cover restraint systems. Devices designed to restrain the cover must be able to withstand explosive forces and react in sufficient time to reduce internally generated pressures. By understanding the fundamental characteristics of arcing faults and gas explosions and their effect on the internally generated pressures, safety devices can be designed to mitigate the effects of the event in manholes and vaults and thereby reduce the potential danger to maintenance crews, first responders and the public.

Online tracking of fault location in distribution systems based on PMUs data and iterative support detection

Fast and accurate locating of electrical faults along power networks enhances system reliability and continuity of supply, quick reclamation of the power supply and subsequently decreasing service outage time. This paper introduces a new technique for online tracking of fault location in distribution networks based on system measurements available from Phasor Measurement Units (PMUs) and Iterative Support Detection (ISD) technique. During and prefault, the voltages are measured by PMUs which are optimally located along the network. From the voltage change vector and system impedance matrix, a current change vector involving a nonzero element corresponds to the faulty point is obtained. Since PMUs are not placed at all buses, the acquired system equation is underdetermined. Therefore, ISD technique is used to solve and recover the current vector that is sparse in nature. The proposed method is verified by applying it to an 11-bus system, with and without the presence of Distributed Generation (DG). The method is then implemented on a 104-bus real distribution network in Egypt. Different case studies are presented considering the effect of fault resistance and measurement noises. A comparative study is proceeded to illustrate the performance of the proposed method. Results clarify that this method performs effectively for different network topologies and circumstances.

Fault Diagnosis and Asset Management of Power Transformer Using Adaptive Boost Machine Learning Algorithm

Dissolved Gas Analysis (DGA) data of liquid insulation used to find the incipient faults such as partial discharge, thermal faults of various temperatures, discharge of high and low energy faults, combination of electrical and thermal faults in transformers. The conventional approaches of DGA namely Gas Ratio method, Duval triangle method and the Neural Network seems to be time consuming and sometimes yield erroneous results. In this paper, Adaptive BOOST machine learning algorithm is proposed, which is effective in classifying the transformer incipient faults. The results of proposed algorithm is compared with the results of different other machine learning algorithms such as K-Nearest Neighbor (KNN), Support Vector Machine (SVM), Decision Tree, Ensembler algorithm for the same set of transformers data. From the comparison, it is evident that ADABOOST machine learning algorithm performs well.

Application of airborne electromagnetic method in the exploration of Qingchengzi mine in Liaoning Province, China

Qingchengzi area of Liaoning Province is an important concentration of polymetallic minerals in China. But with the long-term mining, Qingchengzi mining area has become a crisis mine, and the prospecting and prediction in the mining area has become a key work. The resistivity data is closely related to the existence of minerals. We carried out the VTEM airborne electromagnetic observation in this area. The primary processing results show that the inversion result is very consistent with the existing geological information. The processing results of airborne electromagnetic data will provide an important guarantee for the electrical structure, fault distribution and structural framework in the ore concentration area, as well as the delineation of the mineral target area.

Development of Pure Electric Vehicle Fault Diagnosis System Based on Virtual Reality Fusion Technology

At the present stage, pure electric vehicles are developing rapidly, and all aspects of pure electric vehicles have been developed comprehensively. However, there are still some problems in the fault diagnosis system of pure electric vehicles. The fault diagnosis system of pure electric vehicles can not meet the needs of consumers. Therefore, at the current stage, the development of fault diagnosis system for pure electric vehicles is A problem. The appearance of virtual reality fusion technology can help the development of pure electric vehicle fault diagnosis system. This paper mainly discusses how to develop the fault diagnosis system of pure electric vehicle based on virtual reality fusion technology.

Mathematical Modelling and IoT Enabled Instrumentation for Simulation & Emulation of Induction Motor Faults

Simulation and emulation of electric motor faults are particularly useful to study, test, and evaluate the motor condition monitoring products based on the motor current signature and vibration analysis. Many researchers have proposed and developed several DAQ & computer-based simulation tools. This paper aims to develop a system to simulate and emulate the maximum types of faults which can occur in a three-phase induction motor. In this paper, an embedded system based induction motor fault simulator and the emulator is proposed and developed. The focus of this paper is to model the induction motor faults mathematically based on the motor current signature and vibration frequency spectrum, which are theoretically derived and proved by the early generation researchers and engineers. The novelty of the proposed approach is a cost-effective, portable, and handy tool for field evaluation of the motor condition monitoring products. This paper presents the hardware and software development for making a stand-alone motor faults simulator and emulator. The system employs a powerful high-end and powerful embedded system INTEL ATOM Minnow Board, which is built around E3826, Dual Core, and 1.46 GHz processor. A dedicated 4-channel Direct Digital Synthesizer (DDS) with 12-bit resolution along with software generates all three-phase induction motor faults for both MCSA and vibration analysis. The simulated and emulated faults signals are compared and evaluated against the Standards with the help of a digital storage oscilloscope.

Failure of submarine cables used in high‐voltage power transmission: Characteristics, mechanisms, key issues and prospects

This study reviews the failure of high-voltage submarine cables used in offshore power transmission and provides highlights of their failure characteristic, mechanisms, key issues and prospects. High-voltage submarine cables are designed and applied according to the high-voltage alternating current and high-voltage direct current requirements. Inevitably, the fault occurs in HV submarine cables that is different from that of an underground cable. External aggression remains the primary cause of faults, such as fishing and anchors. Most faults continue to occur at a shallow depth (300 m). The optical fiber inside the submarine cables plays a substantial role in the temperature and stress-strain monitoring and diagnosis. However, it is regarded as a weak point for electrical fault. Insulation breakdown is the leading reason for the short fault. The failure mechanism is complicated when associated with marine conditions. Some defects of insulation and extensive voids, water treeing, mechanical stress, partial discharges, overheating, and electrochemical erosion contribute to the insulation breakdown. Several key issues, including anchoring damage, treeing, defects, and thermal-electric ageing, are proposed. Prospects and new methods related to the cable failure, especially for insulation ageing by treeing and electrothermal effects, are also discussed.