Circuit Fault Detection Research Articles

Induction Motors Stator Fault Analysis based on Artificial Intelligence

This article presents a method for fault detection and diagnosis of stator inter-turn short circuit in three phase induction machines. The technique is based on the stator current and modelling in the dq frame using an Adaptive Neuro-Fuzzy artificial intelligence approach. The developed fault analysis method is illustrated using MATLAB simulations. The obtained results are promising based on the new fault detection approach.

Fault Detection Circuit Based on IGBT Gate Signal

The detection circuit presented in this paper has the purpose of detecting short circuit and open circuit faults in insulated gate devices (IGBT). The detection circuit design is based on the analysis of the IGBT gate signal VGE, which is characterized by carrying out the fault detection within the IGBT switching times under test. The fast fault detection is due to the following considerations: a) Employing technology components with a high slew rate, allows the detection within the switching times, b) Employing fewer components allow the circuit design less expensive and faster, and This paper presents the experimental validation results for the proposed fault detection cases.

A novel fault diagnosis method in SVPWM voltage-source inverters for vector controlled induction motor drives

This paper presents a novel single and multiple open circuit fault detection and identification method for three phase Voltage Source Inverter (VSI) fed vector controlled drives. In healthy condition, d-axis reference voltage is constant. When fault occurs, it is distorted, which is applied to dete ct the insulated-gate bipolar transistors (IGBTs) open circuit fault occurrence. The d-axis reference voltage distorted last for an interval time, the fault can be isolated by calculating the instant current vector rotating angles when the d-axis reference voltage gets distorted and recovered to constant, respectively, combined with space position of the current arc trajectory. The proposed method is fair robust to load torque changes and variable speed, and can be embedded into the existing drive software as a subroutine without excessive computational effort. The feasibility of the proposed fault diagnosis algorithm is evaluated by both simulation and experimental results.

Inter-turn short-circuit fault detection in saturable squirrel-cage induction motor using magnetic equivalent circuit model

Purpose – The purpose of this paper is to obtain an integrated method for inter-turn short circuit fault detection for the cage-rotor induction machine (CRIM) considering saturation effect. Design/methodology/approach – The magnetic equivalent circuit (MEC) is proposed for machine modeling and nonlinear B-H curve is considered for saturation effect. The machine has some differential equations which are converted to algebraic type by trapezoidal method. On the other hand, some nonlinear equations are present due to saturation effect. A set of nonlinear algebraic equation should be solved by numerical method. Therefore, the Newton-Raphson technique is used for equation solving during of the considered time step. Findings – Generally, the operating point of electrical machines is close to the saturation zone due to designing considerations. Moreover, some current and torque harmonics will be produced due to time and space harmonics combination, which cannot be studied when saturation modeling is neglected. Considering both space and time harmonics, a method is proposed for inter-turn short circuit fault detection based on the stator current signatures and the machine performance is analyzed in healthy and faulty cases. In order to obtain the integrated method, two sample machines (two and also four-pole machines) are modeled and finally the accuracy of the proposed method is verified through the experimental results. Research limitations/implications – The calculations have been done in this work is limited to CRIM considering. However, the presented modeling method can be used for another types of electrical machines by some minor modifications. Originality/value – Obtaining of an integrated formula for the inter-turn short circuit fault detection which has been presented for first time is the more advantages of present work. Moreover, in order to saturation effect considering, a new method is presented for solving of nonlinear equations which is another novelty of paper.

Design of Arc Fault Detection Circuit in Low Voltage Switchboard

Design of Arc Fault Detection Circuit in Low Voltage Switchboard

Simplified fault tolerant finite control set model predictive control of a five-phase inverter supplying BLDC motor in electric vehicle drive

Multiphase brushless direct current (BLDC) motors can meet the increasing demand for higher reliability in motor drives applicable in electric vehicles by integrating fault diagnosis to a fault-tolerant (FT) control method. To achieve this goal, a modified FT finite control set model predictive control (FCS–MPC) is proposed in this paper. The dead beat control is used to predict the reference voltage applied by the inverter. A sensitivity analysis is done to show the effect of model uncertainty on the controller performance. In addition, a simple, fast and general open switch and short circuit fault detection (FD) method in voltage source inverter (VSI) is presented. The FD method is capable of detecting open switch, open phase, and short circuit faults without any auxiliary variable. Moreover, it is robust to both speed and load transients in a motor drive. To validate the presented theory, experimental results are conducted on a five-phase BLDC motor drive with outer rotor in wheel structure.

Developing a power monitoring and protection system for the junction boxes of an experimental seafloor observatory network

A power monitoring and protection system based on an embedded processor was designed for the junction boxes (JBs) of an experimental seafloor observatory network in China. The system exhibits high reliability, fast response, and high real-time performance. A two-step power management method which uses metal-oxide-semiconductor field-effect transistors (MOSFETs) and a mechanical contactor in series was adopted to generate a reliable power switch, to limit surge currents and to facilitate automatic protection. Grounding fault diagnosis and environmental monitoring were conducted by designing a ground- ing fault detection circuit and by using selected sensors, respectively. The data collected from the JBs must be time-stamped for analysis and for correlation with other events and data. A highly precise system time, which is necessary for synchronizing the times within and across nodes, was generated through the IEEE 1588 (precision clock synchronization protocol for networked measurement and control systems) time synchronization method. In this method, time packets were exchanged between the grandmaster clock at the shore station and the slave clock module of the system. All the sections were verified individually in the laboratory prior to a sea trial. Finally, a subsystem for power monitoring and protection was integrated into the complete node system, installed in a frame, and deployed in the South China Sea. Results of the laboratory and sea trial experiments demonstrated that the developed system was effective, stable, reliable, and suitable for continuous deep-sea operation.

Open-circuit fault diagnosis and voltage sensor fault tolerant control of a single phase pulsed width modulated rectifier

Recently, single phase pulsed width modulated (PWM) rectifiers become very attractive in different industrial applications that need connection to single phase grid. Like any other PWM converter, the single phase PWM rectifier may be subject to different failures like power switch failures or sensor faults. Hence, fault diagnosis and monitoring are essential to optimize the maintenance costs and increase the reliability levels of the system. This paper discusses the fault detection and isolation (FDI) of both failures. A new open circuit fault detection and isolation approach is proposed. The fault detection method is based on residual generation between measured and observed current form factors (CFFs) with an adaptive threshold in order to avoid the false alarm and increase the reliability of the diagnosis algorithm. Also, the grid voltage sensor FDI is considered in this contribution thanks to the use of parity space equations approach. Moreover, after sensor fault detection and isolation, a grid virtual flux estimator is used to achieve the grid voltage sensor fault tolerance (FTC). Each failure may be detected in few hundred of microseconds. Theoretical analysis, simulations and experimental results are presented to validate the effectiveness of the proposed method.

Fault detection in analog and mixed-signal circuits by using Hilbert–Huang transform and coherence analysis

Using Hilbert–Huang transform (HHT) and coherence analysis, a signature extraction method for testing analog and mixed-signal circuits is proposed in this paper. The instantaneous time–frequency signatures extracted with HHT technique from the measured signal of circuits under test (CUT) are used for faults detection that is implemented through comparing the signatures of faulty circuits with that of the fault-free circuit. The coherence functions of the instantaneous time–frequency signatures and its integral help to test faults in the faulty dictionary according to the minimum distance criterion. The superior capability of HHT-based technique, compared to traditional linear techniques such as the wavelet transform and the fast Fourier transform, is to obtain the subtle time-varying signatures, i.e., the instantaneous time–frequency signatures, and is demonstrated by applying to Leapfrog filter, a benchmark circuit for analog and mixed-signal testing, with 100% of F.D.R (fault detection rate) in the best cases and with the least 24.2% of F.L.R. (fault localization rate) with one signature.

Fault diagnosis and on-line monitoring for grid-connected single-phase inverters

The functionality of power electronic converter systems (PECS) is a cornerstone in various industrial applications. One of the key requirements to ensure reliable functions of PECS is the analysis of their behavior during fault conditions. Characterizing the behavior of PECS during the fault conditions can provide a standpoint for enhancing their control and protection algorithms. Moreover, effective solutions for on-line monitoring for PECS are significant in order to improve the system supervision and management. Consequently, this paper presents fault diagnosis and on-line monitoring schemes for grid-connected single-phase inverters in typical commercial PECS utilized for renewable energy distributed generation. The paper provides fault detection, classification and location of the open circuit (O-C) faults which do not trigger the standard protection systems in the single-phase inverters. The proposed fault diagnostic algorithm is implemented by adaptive neuro fuzzy inference system (ANFIS) algorithm and it is based solely on the inverter output current measurements. Therefore, the proposed algorithm requires much fewer inputs compared to the previous research works. Furthermore, the paper implements an on-line monitoring by using a communication interface board which is connected to graphical user interface (GUI) software through transmission control and internet protocols (TCP/IP). The GUI software integrates the on-line monitoring for the electrical signals of the single-phase inverter, as well as incorporates a real time database for these signals.

Fault detection in analogue circuits using hybrid evolutionary algorithm and neural network

With the development of analog integrated circuits technology and due to the complexity, and various types of faults that occur in analog integrated circuits, fault detection is a new idea, has been studied in recent decades. In this paper a three amplifier state variable filter is used as circuit under test (CUT) and, a hybrid neural network is proposed for soft fault diagnosis of the CUT. Genetic algorithm (GA) has the powerful ability of searching the global optimal solution, and back propagation (BP) algorithm has the feature of rapid convergence on the local optima. The hybrid of two algorithm will improve the evolving speed of neural network. GA-BP scheme adopts GA to search the optimal combination of weights in the solution space, and then uses BP algorithm to obtain the accurate optimal solution quickly. Experiment results show that the proposed GA-BP scheme is more efficient and effective than BP algorithm.

Research on the Optimization Model of Fault Detection for Large-Scale Electronic Circuit

In current large-scale electronic circuit devices, failure data calibration capacity is not strong and it is difficult to be precise classification and intelligent judgment. It lacks of the necessary mechanisms to eliminate the error message, bringing troubles to fault detection. In order to avoid the above defect, this paper presents a fault detection method for large-scale electronic circuit based on fuzzy clustering algorithm. Firstly, the use of means clustering method, the fault information is made initial classification. Then, using the second fuzzy clustering method make fault information filtering in different categories, in order to achieve the fault data confirmation. Experimental results show that the proposed algorithm can effectively improve the accuracy of fault detection of large-scale electronic circuit.

Design and Implementation of the Controller of Active Power Filter Based on Dual-DSP

This paper has designed an active power filter control system with dual digital signal processor (DSP) core, which meets the requirements of functional and intelligent design of the active power filter (APF), and improves the real-time performance efficiency of the controller. Firstly, the structure of the controller hardware system design process, as well as major hardware modules were analyzed in detail; Then in-depth analysis of AD conditioning circuit module, analog-to-digital converter module, dual-port RAM modules and fault detection circuit module as well as the dual DSP program process was introduced. Finally the real-time performance and accuracy of the designed controller was proved by the performance test.

Design of Side Line Short Circuit Detection Device Load of Low Voltage Circuit Breaker before Closing

It uses MSP430F2274, the ultra low power microcontroller, as the control core of short circuit detection device, through the accurate measurement of low voltage circuit breaker load side of the main wiring of insulation resistance value and the interphase insulation resistance value, outputting high voltage startup sound and light alarm device, and then accomplish the open circuit fault detection. Testing power supply is the use of magnetic coupling resonance principle, from the main power grid electrical insulation for short circuit detection device. The device has the advantages of low cost, small volume, good safety, good detection effect, and can be embedded in use in low voltage circuit breaker.

Design on Laser Diode Temperature Control Circuit

This thesis designs a new model of thermal control circuit based on the in-depth study on the temperature control of laser, in order to make laser to work under a constant temperature. This circuit uses ADN8831 as the key chip, combines PWM control scheme. It has accomplished the design of input stage, compensative links, output stage, filter circuit, protection and fault detection of hardware circuit. After actual laser experiments, the precision of temperature can be controlled up to 0.01°C. Experiments show that this circuit is of high efficiency, small size, high reliability, and strong driving ability. It will provide constant temperature control for laser device.

Distributed Fault Detection System Design Based on the Communication Protocol

This article analyze the transmitting characteristics of information in the modern And than, we find the basic design criterion of fault detection system in the complicated electronic devices. Than we discuss the possibility of achieving fault detection through a communication protocol. So we describe the design project of achieving detecting fault function through the communication protocol. At last, we brief introduce simulative detection function about fault detection circuit.

Inter-Turn Fault Detection in PM Synchronous Machines by Physics-Based Back Electromotive Force Estimation

In this paper, the inter-turn short circuit fault detection in permanent magnet synchronous machines (PMSM) using an open-loop physics-based back electromotive force (EMF) estimator is presented. The back EMF estimator is designed based upon a current mode tracking scheme. The thermal and saturation aspects of the machine are considered in the design of the estimator. The design procedure and stability criteria of the estimator are presented in detail. The fault detection is carried out based on the difference between the estimated back EMF and a reference back EMF. A 0.8 (kW) PMSM is studied experimentally as well as numerically under different inter-turn fault and operational contingencies. The numerical modeling is accomplished by a finite-element-based model coupled with the thermal network and polluted with inter-turn fault. The acceptable agreement between the simulated and experimental result validates the modeling process. The back EMF estimator fault detection system is led to discriminative inter-turn fault signatures in a fraction of second for wide speed range even in the presence of harmonic loads and dynamic eccentricities.

Overhead Power Line Fault Positioning System

Aimed at the situations of the low accuracy of overhead line fault detection and the high cost of line fault information transmission with the aid of GSM correspondence network, this paper introduces overhead line fault detection and location system as the core of industrial computer. The combination of software and hardware, the methods of current rate of change and zero current detection are used, and so the accuracy of short circuit fault detection is improved. The features of ground phase voltage drop and the 5th harmonic current are integrated, and the accuracy of ground fault detection circuit is improved. Zigbee wireless communication technology is used to make into independent signal transmission system, which not only reduces the system's operating costs but also ensures the reliable transmission of signals. Taking Kingview 6.51 software as development platform, the monitoring program and display with many functions are designed. The system has been put into operation, running in good condition, and passed concluding and acceptance smoothly.

Study on Fault Detection and PCB Picture-Location Method of Logic Circuit

The main content of logic circuit fault detection includes describing circuit to be diagnosed, determining fault and circuit initial information, generating circuit location test set. In this study, LASAR is used to carry out the logic circuit simulation so as to create such documents as fault dictionary, node truth value table, etc. for the preparation of fault detection. Due to the limitation of circuit observability and testing vectors, the diagnosis program can not accurately locate the fault just once in the process of diagnosis because the circuit is complex and users are not quite familiarity with the circuit. Therefore, the new circuit-fault-detection technology incorporates techniques of PCB picture-location so that the users can locate the fault quickly and accurately.

Software Reliability Testing using Monte Carlo Methods

Monte Carlo method is used in this paper to test the software reliability. The Monte Carlo method is a technique that can be used to solve mathematical or statistical problems. Monte Carlo simulation uses frequent sampling to determine the properties of some phenomenon. There have been very rare uses of such simulation methods for software testing. This paper provides an accurate algorithm for testing software based on Monte Carlo Methods. The results would decide the percentage reliability of the software. This scheme has a number of applications in financial analysis, Econometric, statistics, software testing, fault detection in circuits and many more.