Showing papers on "Fault indicator published in 2019"

Enhanced Particle Filtering for Bearing Remaining Useful Life Prediction of Wind Turbine Drivetrain Gearboxes

Abstract: Bearing is the major contributor to wind turbine gearbox failures. Accurate remaining useful life prediction for drivetrain gearboxes of wind turbines is of great importance to achieve condition-based maintenance to improve the wind turbine reliability and reduce the cost of wind power. However, remaining useful life prediction is a challenging work due to the limited monitoring data and the lack of an accurate physical fault degradation model. The particle filtering method has been used for the remaining useful life prediction of wind turbine drivetrain gearboxes, but suffers from the particle impoverishment problem due to a low particle diversity, which may lead to unsatisfactory prediction results. To solve this problem, this paper proposes an enhanced particle filtering algorithm in which an adaptive neuro-fuzzy inference system is designed to learn the state transition function in the fault degradation model using the fault indicator extracted from the monitoring data; a particle modification method and an improved multinomial resampling method are proposed to improve the particle diversity in the resampling process to solve the particle impoverishment problem. The enhanced particle filtering algorithm is applied successfully to predict the remaining useful life of a bearing in the drivetrain gearbox of a 2.5 MW wind turbine equipped with a doubly-fed induction generator.

Simultaneous Placement of Fault Indicator and Sectionalizing Switch in Distribution Networks

Abstract: Automation systems provide substantial improvement in service reliability through speeding up fault management procedure. However, this is at expense of high investments whose justification needs thorough cost/worth analyses. This paper introduces a mathematical model to optimally place automation system devices within distribution networks. The model establishes a trade-off between service reliability improvements and the relevant costs. Among different automation system devices, fault indicators and remote controlled switches are considered here. Also, the impact of manual switches is regarded since their number and location significantly affect the solution of the placement problem. The proposed model is developed in the mixed integer programming format which can be effectively solved via available solvers. The effectiveness of the proposed model is demonstrated through a test system and a real-life distribution network. The obtained results indicate the great performance of the model in enhancing service reliability as well as reducing system costs.

A combined mono- and multi-turbine approach for fault indicator synthesis and wind turbine monitoring using SCADA data

Abstract: The monitoring of wind turbines using SCADA data has received lately a growing interest from the fault diagnosis community because of the very low cost of these data, which are available in number without the need for any additional sensor. Yet, these data are highly variable due to the turbine constantly changing its operating conditions and to the rapid fluctuations of the environmental conditions (wind speed and direction, air density, turbulence, …). This makes the occurrence of a fault difficult to detect. To address this problem, we propose a multi-level (turbine and farm level) strategy combining a mono- and a multi-turbine approach to create fault indicators insensitive to both operating and environmental conditions. At the turbine level, mono-turbine residuals (i.e. a difference between an actual monitored value and the predicted one) obtained with a normal behavior model expressing the causal relations between variables from the same single turbine and learnt during a normal condition period are calculated for each turbine, so as to get rid of the influence of the operating conditions. At the farm level, the residuals are then compared to a wind farm reference in a multi-turbine approach to obtain fault indicators insensitive to environmental conditions. Indicators for the objective performance evaluation are also proposed to compare wind turbine fault detection methods, which aim at evaluating the cost/benefit of the methods from a production manager's point of view. The performance of the proposed combined mono- and multi-turbine method is evaluated and compared to more classical methods proposed in the literature on a large real data set made of SCADA data recorded on a French wind farm during four years : it is shown than it can improve the fault detection performance when compared to a residual analysis limited at the turbine level only.

Induction Motor Stator Interturn Short Circuit Fault Detection in Accordance with Line Current Sequence Components Using Artificial Neural Network

Abstract: The intention of fault detection is to detect the fault at the beginning stage and shut off the machine immediately to avoid motor failure due to the large fault current. In this work, an online fault diagnosis of stator interturn fault of a three-phase induction motor based on the concept of symmetrical components is presented. A mathematical model of an induction motor with turn fault is developed to interpret machine performance under fault. A Simulink model of a three-phase induction motor with stator interturn fault is created for extraction of sequence components of current and voltage. The negative sequence current can provide a decisive and rapid monitoring technique to detect stator interturn short circuit fault of the induction motor. The per unit change in negative sequence current with positive sequence current is the main fault indicator which is imported to neural network architecture. The output of the feedforward backpropagation neural network classifies the short circuit fault level of stator winding.

Intelligent Fault Diagnosis Techniques Applied to an Offshore Wind Turbine System

Abstract: Fault diagnosis of wind turbine systems is a challenging process, especially for offshore plants, and the search for solutions motivates the research discussed in this paper. In fact, these systems must have a high degree of reliability and availability to remain functional in specified operating conditions without needing expensive maintenance works. Especially for offshore plants, a clear conflict exists between ensuring a high degree of availability and reducing costly maintenance. Therefore, this paper presents viable fault detection and isolation techniques applied to a wind turbine system. The design of the so-called fault indicator relies on an estimate of the fault using data-driven methods and effective tools for managing partial knowledge of system dynamics, as well as noise and disturbance effects. In particular, the suggested data-driven strategies exploit fuzzy systems and neural networks that are used to determine nonlinear links between measurements and faults. The selected architectures are based on nonlinear autoregressive with exogenous input prototypes, which approximate dynamic relations with arbitrary accuracy. The designed fault diagnosis schemes were verified and validated using a high-fidelity simulator that describes the normal and faulty behavior of a realistic offshore wind turbine plant. Finally, by accounting for the uncertainty and disturbance in the wind turbine simulator, a hardware-in-the-loop test rig was used to assess the proposed methods for robustness and reliability. These aspects are fundamental when the developed fault diagnosis methods are applied to real offshore wind turbines.

Bearing Faults Classification Based on Variational Mode Decomposition and Artificial Neural Network

Abstract: Bearing fault is the most causes of machine breakdowns. Consequently, the monitoring of this component is a key point to increase the reliability, security and avoiding serious damage in machine. Vibration signal is widely used for diagnosis which is considered as a powerful tool for detecting mechanical defects. In this paper, a rolling bearing fault-diagnosis method based on variational mode decomposition (VMD) and artificial neural network (ANN) is proposed. First, the processing methodology of bearing diagnosis starts with the decomposition of the vibration signal by VMD technique into a set of intrinsic mode functions (IMFs). According to the aim of fault diagnosis, the selected fault indicator is calculated from the energy related to the most sensitive IMFs to the bearing defect. Second, the extracted feature is then used as input to the ANN. the proposed approach is then validated using data from the bearing data center of Case Western Reserve University. The results prove the efficient of this method which is able to discriminating from four conditions of rolling bearing, namely, normal bearing and three different types of defected bearings: outer race, inner race, and ball.

Application of LoRa and NB-IoT in Ubiquitous Power Internet of Things: A Case Study of Fault Indicator in Electricity Distribution Network

Abstract: Traditional communication technologies based on 2G and 4G cannot meet the requirements of low-power wide-area data transmission in electricity distribution network. Ubiquitous power Internet of things (UPIoT) has thus been proposed by the State Grid of China and it can be used to transmit energy information requested from any location. Narrowband Internet of things (NB-IoT) and LoRa are two promising low-power wide-area communication technologies, which are capable of providing good performance to transmit data collected from the devices installed in the distribution network. In this paper, taking the fault indicator as an example, we combine LoRa and NB-IoT to construct a wireless network to transmit the operation status of fault indicator, which can improve the transmission distance and reduce the operating cost of the system. It adopts a communication mode including a master node and a plurality of child nodes to meet the needs of large-scale information monitoring. Among them, the design of the master node uses NB-IoT and LoRa communication technologies. The design of the child node uses LoRa communication technology and sensor technology. The control chip STM32F103C8T6 is used for data transmission, and the data is finally managed by a centralized means through upper computer software.

Small current ground fault location method and system for distribution network

Abstract: The invention discloses a small current ground fault location method for a distribution network on the basis of multi-source information and transient state wave recording, comprising the following steps: acquiring a bus ground alarm moment t by a power distribution automation master station; when current break of a distribution line is higher than a threshold value I or electric field intensity of the distribution line is higher than a threshold value E, starting wave recording by virtue of a transient state wave recording type fault indicator mounted on the distribution line, and forming a wave recording file; sending all the wave recording files of a lower distribution line of a transformer substation in a plurality of minute intervals before and after the moment t on establishing incidence relation between a mounting position of a fault indicator and the wave recording file on circuit topology by the distribution line automation master station; extracting a zero sequence voltage phase and a zero sequence current phase of each wave recording file by the power distribution automation master station; and according to a relative direction of zero sequence voltage and zero sequencecurrent, judging a relative position of a grounding fault point and a fault indicator, and finally determining a ground fault section.

Fault diagnosis of wind turbine bearing using synchrosqueezing wavelet transform and order analysis

Abstract: In this study, a two-steps method is proposed to diagnose the wind turbine bearing fault under the variable speed condition without using a tachometer. In the first step, the synchrosqueezing wavelet transform is used to process the bearing vibration signal to extract the rotating phase from the time-frequency plane. In the second step, the original time-domain vibration signal is resampled according to the extracted rotating phase, and then the bearing fault indicator can be recognized in the envelope order spectrum for fault diagnosis. The effectiveness of the proposed method is validated on a direct-drive wind turbine test rig in which a fault bearing is installed on a permanent magnet synchronous generator.

Information Model of Centralized Feeder Automation Based on IEC 61850

Abstract: To facilitate the interconnection and interoperability between distribution master station and the terminal device, the centralized feeder automation, which has been widely applied in distribution networks, needs an information model in accordance with IEC 61850. This paper introduces the logic node related to fault indicator in the technical report of IEC61850-90-6. Based on the modeling principle of centralized feeder automation functions, applying the new definition of current indicator logical node SCPI, voltage indicator logical node SVPI, fault indicator logical node SFPI, an information model of centralized feeder automation is studied to demonstrate the application of IEC 61850 in distribution automation.

Multilevel Inverter Fault-Tolerant Control with Wavelet Index in Induction Motor

Abstract: The wavelet based fault tolerant control (FTC) is a new aspect in the industrial applications, and it’s often used in both high-power high-voltage motor drive applications. To ensure the smooth operation of the control system, the researchers perform more fault-tolerant control systems (FTCS). In this work, a FTCS in the induction motor (IM) using wavelet index introduced. The operation of the power devices of a three-level diode-clamped multilevel inverter under variable load and short stator winding fault is analyzed through MATLAB simulation. The wavelet index of output speed, torque and flux used to detect faulty operation due to its deviation with healthy wavelet index. The feature extraction property of wavelet analysis used as input to the expert system to develop a fault indicator. The diagnosis algorithm, which depends on both wavelet and vector control to generate PWM as current based not only detects short stator winding faults but manage any parameter variation such as speed, torque and flux. The lockup table models used to build correction unit to estimate the satisfactory speed, torque and flux. The proposed method is effective in many situations to check the vector control algorithm, and has a satisfactory fault tolerant operation.

Power distribution network fault positioning system and method

Abstract: The invention provides a power distribution network fault positioning system and method, and relates to the technical field of power distribution network fault positioning; the power distribution network fault positioning system comprises a multi-source data acquisition terminal, a collection terminal and a master station system, wherein the multi-source data acquisition terminal acquires electrical parameters of a power distribution network to be monitored and sends the electrical parameters to the collection terminal; the collection terminal determines integrated electrical parameters basedon the received electrical parameters and sends the integrated electrical parameters to the master station system so that the master station system determines fault information of the power distribution network to be monitored; the multi-source data acquisition terminal comprises at least one of the following: a fault indicator, a power distribution switch monitoring terminal, an intelligent lightning arrester, a smart switch, and a metering automation device; the master station system comprises at least an expert system, a geographic information system, a weather system, and a patrol information system. According to the fault positioning system, the master station system is used for comprehensively judging integrated electrical parameters, so that the accuracy of fault information is ensured, and the technical problems of misjudgment and misjudgment of the existing fault positioning method of the distribution network are relieved.

Fault indicator data-based fault type identification method of small-current grounding distribution network

Abstract: The invention discloses a fault indicator data-based fault type identification method of a small-current grounding distribution network. A fault indicator is arranged on a power transmission line, anacquisition unit is arranged on the fault indicator, the acquired three-phase current data is transmitted to a convergence unit by the acquisition unit, the three-phase current data is collected by the convergence unit, a three-phase current data set is formed and sent to an identification unit, the identification unit is used for identifying according to the following steps of (1) identifying a single-phase grounding fault and a short-circuit fault; (2) identifying symmetric short circuit and a non-symmetric short circuit; and (3) identifying two-phase short circuit and two-phase grounding short circuit. The A/D saturation characteristic and zero-sequence voltage characteristic of the current data of the fault indicator are used, the method is simple and effective and is high in practicability, and application in an existing distribution network automatic system is facilitated.

Externally applied signal recognition type fault indicator and fault location method

Abstract: The invention discloses an externally applied signal recognition type fault indicator. The externally applied signal recognition type fault indicator comprises an acquisition unit arranged on a circuit and a collecting terminal in communication connection with the acquisition unit, the collecting terminal is used for collecting data sent by the nearby acquisition unit and reporting the data to a background, and the acquisition unit comprises a CT electricity taking device, a power management module, an MCU, a wireless communication module, an analog sampling module, a fault logic judgment module and an alarm, wherein the CT electricity taking device is used for supplying power, the power management module is connected with the CT electricity taking device, and the wireless communication module, the analog sampling module, the fault logic judgment module and the alarm are connected with the MCU separately. The invention further discloses a grounded short circuit location method which can locate accurate fault location points. The externally applied signal recognition type fault indicator and the grounded short circuit location method have the advantages that fault lines and fault points can be quickly indicated, the labor intensity of line patrol walkers is reduced, and the troubleshooting time is shortened; the duration of power outage is reduced, and the power supply quality is improved so as to avoid the impact of traditional multiple switching-off, switching-on and line patrol on power equipment; the line fault indicator directly detects signals online, thereby not affecting the normal operation of a power grid, the movement is sensitive and accurate, and the anti-interference capability is strong.

Systems and methods for mesh restoration in networks due to intra-node faults

Abstract: Systems and methods are in a node in a network utilizing a control plane for triggering mesh restoration due to intra-node faults, and include monitoring at least one channel at a degree at a plurality of degrees associated with the node; detecting a fault on the at least one channel, wherein the fault is an intra-node fault upstream of the degree; and transmitting a channel fault indicator downstream of the fault to at least one downstream node along a path of the faulted channel, wherein restoration is triggered based on the channel fault indicator.

Design and Implementation of a new Fault Indicator for Power System based on Ultra-Low-Power MCU

Abstract: With the increasing scale of the power grid, real-time monitoring requirements for on-site data of power systems in various countries around the world are getting higher and higher. The high-voltage distribution network is widely distributed, spanning rivers, rivers, mountains, deep valleys, jungles, and other complex and variable environments so that it is susceptible to short-circuit faults caused by various natural disasters and other environmental factors. Single-phase ground faults are also common in the grid, and working information and necessary alarm indications during network operation are also important. The real-time monitor of the line current is indispensable for short-circuiting faults, while ground faults need to monitor the zero-sequence voltage in the substation and call the original sampled data for analysis. When there is a transient short-circuit fault in the distribution network, the transmission line resumes operation after reclosing, but the hidden danger still exists. In the fault recording system, the data can be analyzed in time to avoid the fault happening again. For the permanent short-circuit fault, the fault still exists after the gate reclosing. The analyze of recorded data can avoid strong power transmission measures of the system which can reduce the secondary impact and minimize the loss caused by the fault. In response to these functional requirements, this paper designs a new fault recording system and introduces its hardware structure and function implementation.

Fault determination method for fault indicator based on maximum probability

Abstract: The invention discloses a fault determination method for a fault indicator based on maximum probability. The method includes the following steps: 1) establishing a power distribution network minimum fault determination area model; 2) proposing a probability-based fault indicator combined signal processing method according to a principle of "choosing two in three"; and 3) performing fault determination on the fault indicator through combination of the minimum fault determination area model and a fault indicator combined signal, depending on an interdependent relationship between fault indicators, and based on the maximum probability. The method has good fault tolerance in the less case of false signal failing to report and misreporting, can accurately determine fault areas, gives the possible probability of each of areas, provides fault alternative schemes, is convenient to schedule and to intervene and troubleshoot faults by transportation inspection personnel, and has better field application value.

Fault positioning system and method based on transient recording type fault indicator

Abstract: The invention discloses a fault positioning system and method based on a transient recording type fault indicator and belongs to the field of fault positioning. The system comprises a front-end web system, a background master station system, a data acquisition and communication terminal and a fault indicator installed on a line. The fault indicator records the current state of the line and sends its own attribute information and related action information to the data collection and communication terminal, the data collection and communication terminal transmits fault information to the background master station system, after the background master station system receives the action of the fault indicator through the Internet, the background master station system obtains relevant data and performs data interaction, and finally a fault positioning area is generated and displayed in the web system. According to the system and the method, the fault occurrence point can be quickly determined, and the fault detection time of patrol personnel is reduced so as to avoid the occurrence of long-term power failure and improve the reliability of power grid operation.

A fault indicator anti-collision method based on networking communication and a fault indicator

Abstract: The invention discloses a fault indicator anti-collision method based on networking communication and a fault indicator. When multiple sets of fault indicators are networked, the concentrators of different fault indicators carry out networking communication, the collector of each set of fault indicators carries out networking communication with the corresponding concentrator, and when the concentrators carry out networking communication, the working frequency point is determined through the following steps: searching a frequency point to be used; Broadcasting the networking data packet; And judging whether the frequency point to be used is idle or not according to the response condition until the working frequency point is found or all frequency points in a preset frequency point list aresearched. According to the invention, wireless radio frequency channel collision can be avoided, reliable operation of multiple sets of fault indicators is ensured, and the efficiency of fault indicator full detection and production debugging is greatly improved.

Overhead remote transmission type fault indicator with clamping mechanism

Abstract: The utility model discloses an overhead remote transmission type fault indicator with a clamping mechanism. The clamping device comprises an upper cover, a shell and two clamping mechanisms, the two clamping mechanisms are arranged on the front side and the rear side of the shell respectively, each clamping mechanism is composed of a four-rod mechanism and a ratchet mechanism, each four-rod mechanism comprises four connecting rods and two connecting rods, and each ratchet mechanism comprises a ratchet and a stop claw. The four-rod mechanism moves along with the power transmission line and stops until the connecting rod and the connecting rod are collinear, the four-rod mechanism is located at a dead point position, and the stop claw also prevents the ratchet wheel from rotating reversely to ensure that the power transmission line is in a clamping state. The device is simple in structure, convenient to install and high in reliability, only one matched long rod is needed to send the fault indicator to the power transmission line in the installation process, clamping and fixing are achieved through self-locking performance, direct contact with the power transmission line is not neededin the installation process, installation can be conducted within the safe distance range, safety is good, and detection is accurate.

Overhead fault indicator installation tool

Abstract: The utility model relates to the technical field of electric power instrument installation tools. The tool is an overhead fault indicator installation tool. The device comprises an insulating controlrod, a bottom tray and an insulating cylinder, a supporting claw is arranged at the top of the insulating control rod, the bottom tray fixedly connected to the insulating control rod is arranged belowthe supporting claw, the insulating cylinder is arranged on the upper end face of the bottom tray, a spring is arranged in the insulating cylinder, and one end of the spring is fixedly connected to the bottom tray. The device is reasonable and compact in structure; a supporting claw is arranged at the top of an insulating control rod; the spring clamp on the overhead fault indicator can be openedin advance before installation. When the overhead type fault indicator is installed, an operator can flexibly install the overhead type fault indicator at a position where the distance between wiresbetween distribution network lines is small by controlling the insulation control rod, installation difficulty is greatly reduced, hot-line work can be achieved, and much inconvenience caused by construction outage to residents along the line is avoided.

Novel distribution network fault accurate positioning method and device with big data fusion

Abstract: The invention discloses a novel distribution network fault accurate positioning method and device with big data fusion based on smart metering and a line fault indicator. The method comprises a step of collecting real-time data of a line fault indicator and a smart metering device, a step of narrowing a fault detection range according to a capacitor current mutation information logic array and generating an electric meter real-time alarm information matrix based on voltage-losing and current-breaking event warning information reported by a smart metering electric meter in real time, and a stepof obtaining a fault judgment information matrix with the combination of a network description matrix of a load feeder fault interval of a distribution network and outputting a distribution network fault positioning result. By using the method and the device, the accuracy and rapidity of the fault positioning of the distribution network can be improved, and the method and the device have important practical significance for shortening a power outage time, reducing economic loss and improving service quality.

Wide-area current time sequence power distribution network single-phase grounding fault positioning method

Abstract: The invention discloses a wide-area current time sequence power distribution network single-phase grounding fault positioning method. Wave recording type fault indicators are arranged along a distribution line. When a single-phase earth fault occurs in the line, the fault indicators arranged along the line are started and zero sequence current information is recorded, a mathematical relation of zero sequence current, line parameters and fault positions is derived based on a distribution parameter model of the line, and a fault positioning function matrix is constructed by utilizing a wide areacurrent time sequence after the fault; and the fault positioning function matrix is converted into a least square solution for solving a nonlinear equation set, and fault points are searched by usinga chaotic particle swarm algorithm to realize accurate fault positioning. Theoretically, the method is not affected by transition resistance and fault initial angles, positioning errors caused by system errors of the fault indicator can be offset to a certain extent, fault positioning precision is improved, and the method has high practical application value.

Safety fault indicator for distribution network automation

Abstract: The invention, which belongs to the field of distribution network fault indicators, relates to a safety fault indicator for distribution network automation. The safety fault indicator comprises hooks,a shell A, a circular disc A, a display ring, a bevel gear ring, a circular disc B, an arc-shaped bevel gear block, a bevel gear D, an annular disc, a shell B, a piston, a sliding rod, a reset spring, a resistor block, a display sliding plate and a bevel gear C. The two hooks self-locked by means of elasticity are symmetrically installed at the upper end of the shell A made of an insulating materials; and the lower ends of the hooks are arranged in the shell A. The display sliding plate moves under indirect driving of the sliding rod and the displayed color changes; occurrence of a short circuit or disconnection at a high-voltage line at which the indicator is located is indicated; and according to the indication, the maintenance staff inspects the high-voltage line at which the indicatoris located, finds out the short-circuit or disconnection position rapidly, and repairs the line timely, so that the smoothness of the line is ensured.