Faulted Phase Current Research Articles

Analysis of Inter-Turn Short Circuit Faults in Dual Three-Phase PMSM for Electromechanical Actuator

Dual three-phase permanent magnet synchronous machine (DTPM) is an attractive choice for electromechanical actuator owing to its advantages of double redundancy, high power density and high reliability. However, the winding insulation is susceptible to the high thermal and mechanical stress, which will lead to the inter-turn short circuit faults (ITSCF) and poses threat to the safety of the machine system. Moreover, the ITSCF of DTPM is not only limited to single-phase, but also occurs between adjacent phases. Therefore, in this paper, the characteristics of single-phase and phase-to-phase ITSCFs are investigated and compared while the short-circuit contact resistance is considered. Firstly, a general mathematical model for single-phase and phase-to-phase ITSCFs are established, and the expressions of short circuit current (SCC) and output torque are derived. Then, the characteristics of flux density, back-EMF, SCC, fault phase current and output torque of the different fault models are compared by finite element analysis. It is demonstrated that when the contact resistance is not zero ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R_f</i> ≠0), the amplitude of SCC and the third harmonic content of fault phase current are inversely proportional to the contact resistance and proportional to the number of short-circuit turns. In addition, the amplitude of SCC, torque ripple and braking torque caused by a phase-to-phase ITSCF will be larger than those of the single-phase ITSCF under the same fault conditions, especially when the contact resistance is small. Finally, an experimental prototype is made and tested to validate these analyses.

Ground Fault Detection of Small Resistance Grounding System Based on Improved Phase Current Abrupt Variable Method

When a high fault resistance happens in a small resistance ground system, the protection device is simple to be unsuccessful to manage. By analyzing the characteristics of positive, negative currents in the additional state of fault, it is found that the fault detection method constructed only by the phase current increment relationship has risk of misoperation, but relationship among the magnitude of phase current increment can directly reflect the phase of the ground fault. At the same time, the phase location among the fault phase voltage and the current of the unhealthy part and non-fault line is different. Therefore, a ground fault protection method based on the correlation between the phase current increment ratio and the different phase angles of fault phase voltage and current is proposed. We choose the phase with the big phase current mutation as the grounding phase, and affect the fault part by the phase difference between the fault phase voltage and the current of the line. This eliminates the risk of protection maloperation only using the relationship between the size of current increment and protection sensitivity in case of high resistance fault. It can be used for fault phase selection, location, and multi-level protection. The correctness of the way is certificated by simulation.

Detection and Evaluation of the Interturn Short Circuit Fault in a BLDC-Based Hub Motor

A brushless dc (BLDC) motor with an outer rotor has great potential for emerging electric vehicle (EV) applications as an in-wheel hub motor. Interturn short circuit faults (ISCFs) are common electrical faults in these applications, and their fault diagnosis is of critical importance. This article proposes a signal analysis-based method to detect and quantitatively analyze the ISCF in a BLDC motor under a six-step commutation control strategy. The zero-sequence voltage component (ZSVC) and three-phase currents are simultaneously determined while the fundamental frequency amplitude of the ZSVC is developed as a fault indicator for diagnostic purposes. Thereafter, the faulty phase is identified, and the fault severity is estimated by jointly analyzing the ZSVC and faulted phase current. The proposed technique entails creating an analytical model, a simulation model, and experimental tests. Experimental results demonstrate that the proposed technique has excellent accuracy, quick response, and real-time fault diagnosis for BLDC motors. This technique will accelerate the use of BLDC-based hub motors in EVs and the widespread application of EVs to reduce the carbon emissions.

Fault Location Estimator Design for Power Distribution System Using Artificial Neural Network

Fault location in distribution system is critical issue to increase the availability of power supply by reducing the time of interruption for maintenance in electric utility companies. Fault location estimator for power distribution system using artificial neural network is developed for line to ground, line to line, line to line to ground and three phases to ground faults in distribution system. To develop this estimator is one of rural radial power distribution feeder in Ethiopia, south west reign, Aba substation Tarcha line feeder is used as a test feeder. This feeder is simulated using ETAP software to generate data for different fault condition, with different fault resistance and loading conditions, which is the fault phase voltage and current. The generated data is preprocessed and put as an input for neural network to be trained. MATLAB R2016a neural network toolbox to train ANN and programming toolbox is used to develop graphic user interface for fault estimator. The feed forward multi-layer network topologies of neural network with improved back propagation, Liebenberg Marquardt learning algorithm is used to train the network. After the network is trained the mean square error performance, regression plot and error histogram analysis was made and found to have an excellent performance with regression coefficient 0.99929 , validation performance of 0.000102 and error histogram range 0.015 to 0.019. In this thesis for practical implementation the fault records at the test feeder is handled by intelligent electronic device (IED) installed at the substation feeders. The fault record of IED can be read by PCM600 tool using laptop or manually using IEDs human machine interface, this fault recorded data feed to the graphic user interface to estimate the fault location as well as the fault type. Finally it is found that artificial neural networks are one of the alternate options in fault estimator design for distribution system where sufficient distribution network data are available with narrow fault location distance range from the substation. This has benefits in assisting for maintenance plan, saving efforts in fault location finding and economic benefits by reducing interruption time. Keywords : Power distribution, artificial intelligence, neural network, feed forward network DOI: 10.7176/JETP/12-5-01 Publication date: November 30 th 2022

Three-Phase Error Intimation In Sharing System Using IOT

This manuscript develops an automatic tripping mechanism for three phase supply system. The output is giving the information when the any one phase current is zero in three phase supply system. If the fault is happened in a three phase supply system (L-L fault L- G fault) at the time current faulted phase become zero. After few seconds the faulted phase current is will not comes to normal range. It has consider to a phase has been faulted (or) phase current is interrupted in a three phase supply system, so which faulted (or) interrupted in supply system. The respective fault phase information will sended to nearby substation using IOT technique. At the same time by using a relay circuit to disconnect the faulted phase section also to connect the remaining healthy converted into using two phase-three phase converter. The output is verified by the prototype module using Arduino NANO controller. This is intended to understand concerning two basic information of the delay and current transformer in control system. The circuit will segregate the load from the supply if any power variation occurred in a supply system. The major advantage of the research is not only give the information about phase fault (or) phase current interruption and also give the three phase power supply to a load.

Reconstructed Current Model Predictive Control of NPC Three-Level Grid-Tied Converter With Current Sensor Fault

Neutral-point clamped (NPC) three-level grid-tied converter is the key power electronic equipment connecting renewable energy and power grid. High temperature and other factors can lead to current sensor failure, control strategy failure, output current distortion, and even lead to the disconnection of renewable energy. To maintain the normal operation of NPC three-level grid-tied converter with current sensor fault, a model predictive fault-tolerant control strategy based on space voltage vector set and fault phase current reconstruction is proposed. Firstly, the relationship between fault phase current and voltage vector is studied. After the current sensor fault, only 12 out of 27 voltage vectors were found to be able to reconstruct faulty phase currents with a DC current sensor and an AC current sensor. Model predictive current control using the set of these 12 voltage vectors, and fault phase current is directly calculated by DC current and normal phase current, which improves the fault tolerance and stability of the converter system. Finally, simulation and experimental results verified the effectiveness of the proposed method.

Research on fault section location method of distribution networks with arc suppression coil grounding based on energy leakage function

In distribution networks with arc suppression coil grounding, the fault line can be set as the energy leakage channel of the capacitive current of the entire system. During the period from fault occurrence to the whole action process of arc suppression coil, there is abundant fault information in the transient waves. However, the data of this period are usually ignored in previous methods. In this study, a novel fault section location method based on the leakage energy function is proposed. Only the fault phase voltage and fault phase current are used in the proposed method, to avoid the difficulty of the zero-sequence current measurement. Then, the action characteristics of two types of arc suppression devices are analysed. The influence of the capacitor current on the fault phase voltage and current during the entire process of arc suppression coil operation is deduced. The difference between the leakage energy on both sides of the fault section is used as the criterion for fault section location. Finally, the effectiveness of the method is verified by a case study. The simulation results indicate that the proposed method has high sensitivity and high impedance adaptability, that will have more advantages in the actual situations.

Fault diagnosis for three-phase PWM rectifier based on deep feedforward network with transient synthetic features

Three-phase PWM rectifiers are adopted extensively in industry because of their excellent properties and potential advantages. However, while the IGBT has an open-circuit fault, the system does not crash suddenly, the performance will be reduced for instance voltages fluctuation and current harmonics. A fault diagnosis method based on deep feedforward network with transient synthetic features is proposed to reduce the dependence on the fault mathematical models in this paper, which mainly uses the transient phase current to train the deep feedforward network classifier. Firstly, the features of fault phase current are analyzed in this paper. Secondly, the historical fault data after feature synthesis is employed to train the deep feedforward network classifier, and the average fault diagnosis accuracy can reach 97.85% for transient synthetic fault data, the classifier trained by the transient synthetic features obtained more than 1% gain in performance compared with original transient features. Finally, the online fault diagnosis experiments show that the method can accurately locate the fault IGBTs, and the final diagnosis result is determined by multiple groups results, which has the ability to increase the accuracy and reliability of the diagnosis results.

Current Sensor Fault-Tolerant Control for Encoderless IPMSM Drives Based on Current Space Vector Error Reconstruction

Position and current sensors are required in conventional field-oriented control in permanent magnet synchronous motor (PMSM) drives. However, the current sensors subject to various faults, which decreases the reliability. To solve this problem, a single-phase-current sensor encoderless control scheme using a sliding-mode observer (SMO) for fault diagnosis and fault-tolerant control of PMSM drives is proposed in this article. The reconstruction of the faulted phase current is completed through SMO by using the current space vector error projection as the correction term. Then, the equivalent circuit of extended back electromagnetic force estimation is established, and the effect of parameter variations is analyzed based on the vector diagram. The position deviation effect on the current error reconstruction is evaluated. Finally, the effectiveness of the single-phase-current sensor encoderless control is verified by the experiments on a 1.0-kW PMSM drive platform.

Research on Abnormal Identification Technology of Circuit Breaker extinction based on wavelet analysis

Circuit breaker is the actuator of power network fault removal and operation mode conversion. If the circuit breaker itself cannot complete the breaking operation, it may cause the accident impact range to expand, or even cause more serious chain failure. The fault phase current is decomposed based on wavelet analysis and Fourier transform, and the unstructured recorded wave data is converted into structured fault characteristic quantity to realize the analysis of current mutation characteristics. The high frequency characteristic singular value at the occurrence of arc is obtained by wavelet transform, which provides the key characteristic quantity for the identification of abnormal arc extinguishing performance of circuit breaker and realizes the identification of abnormal arc extinguishing state of circuit breaker. Issue an alarm before abnormal expansion of circuit breaker or adverse impact, remind relevant personnel to timely check and deal with defects, reduce the occurrence of abnormal tripping circuit breaker phenomenon.

An adaptive three-phase reclosure scheme for shunt reactor-compensated transmission lines based on the change of current spectrum

In this paper, a new three-phase adaptive reclosing scheme for transmission lines with shunt reactors is proposed to identify fault nature and determine the arc extinction time under the single and double-phase-to-ground faults. According to the fact that the faulted phase currents of shunt reactors contain only one oscillating frequency before the fault extinction and contain other two different oscillating frequencies when the fault is extinguished, this change of current frequency can be used to distinguish transient faults. When sampling rate is an integral multiple of the faulted phase current frequency of shunt reactors under permanent faults, an abrupt increase of currents even harmonics which is caused by spectral leakage of the DFT algorithm under non-synchronous sampling can lead to identify transient faults and three-phase reclosing. Electromagnetic Transient Program simulation results verify the correctness of the frequency spectrum characteristic analysis of the faulted currents of shunt reactor. The feasibility of the proposed scheme is also tested under different fault condition.

Fault Line Selection in Resonant Grounded System Based on IMEn

When the single phase ground fault occurs in resonant grounded system, there are significant differences in the components of fault phase current between fault line and non-fault line. This feature can be reflected by intrinsic mode entropy (IMEn) of fault current. IMEn is a new signal analysis over multiple oscillation levels. It corresponds to the sample entropy (SampEn) and the empirical mode decomposition (EMD). The results of fault simulations in different conditions indicate that the method is reliable.

Single-Line-to-Ground Fault Location in the Compensated Distribution Network

One of the most difficult problems in compensated distribution networks is the grounded fault location. This paper proposes a new method for locating single-line-to-ground (SLG) faults in compensated distribution networks. The grounded fault location system is made up of the host, the controller, the signal generator and the grounded fault indicator (GFI). When a SLG fault occurs, the fault phase is identified firstly, and then a signal generator paralleled with the arc suppression coil injects a special current into the system. Subsequently, GFIs along the fault phase are activated to sample the fault phase current and send it back. The fault phase current is computed by the host with a fast Fourier transform algorithm. By comparing these frequency components of the fault phase current, the fault section is identified based on the significant difference of the second harmonic of two adjacent GFIs. Due to the short length of feeders, the distance between two adjacent GFIs is short enough for line patrol personnel to find and repair the fault easily. Finally, a modified IEEE 13-node feeder test is constructed in PSCAD/EMTDC to evaluate this method. The simulations results confirm the validity of the proposed approach.

A Novel Fault Phase Selector for Double-Circuit Transmission Lines

A novel fault phase selector for double-circuit transmission lines is presented. The fault type is determined with the superimposed components and steady state components of fault voltage. According to the determined fault type, auxiliary criteria based on the magnitude and phase difference of fault phase current is applied to judge whether inter-line fault happens or not. If inter-line fault happens, the fault phase is determined by comprehensive criteria based on the comparison of current magnitude and the judgment of impedance direction. The simulation results verify the correction of the proposed phase selector. DOI: http://dx.doi.org/10.11591/telkomnika.v10i7.1569 Full Text: PDF

Wavelet‐based approach for high impedance fault detection of high voltage transmission line

AbstractThis paper presents a new method for high impedance single‐phase ground fault (HIF) detection based on wavelet transform (WT) in the high voltage transmission line. As high impedance single‐phase ground faults usually have low fault currents, it cannot be easily detected by the conventional protection. The voltages and currents vary simultaneously when a ground fault occurs in the transmission lines, even if it is grounded with a high impedance. Therefore, the signals measured by the protective device contain significant transient components. They have much more fault information than the steady components. With the WT the modulus maxima of the zero sequence current, the faulted phase current, and the zero sequence voltage present special characteristics which can be used to detect HIF. The new scheme can also discriminate if the ground fault locates in the forward zone or the backward zone. The realization of the proposed protection device is also described in this paper. Both simulation and field results show that the scheme can detect HIF with high reliability during all operating conditions. Copyright © 2007 John Wiley &amp; Sons, Ltd.