scholarly journals Determination of Different Fault Features in Power Distribution System Based on Wavelet Transform

2019 ◽  
Vol 8 (4) ◽  
pp. 6256-6261
Keyword(s):  
Signal Processing ◽  
Wavelet Transform ◽  
Power Distribution ◽  
Distribution System ◽  
High Speed ◽  
Short Circuit ◽  
Voltage Waveform ◽  
Power Distribution System ◽  
Time Frequency ◽  
Skewness And Kurtosis

Nowadays, there are various signal processing methods that have been studied by many researchers in order to detect faults in power lines. From previous literature, signal processing that works based on time frequency analysis has been proven to accurately detect faults at high speed. In this study, wavelet transform is adopted to analyse fault occurrences on power line of distribution network. Three types of faults due to lightning, switching and short circuit fault were analysed based on their voltage waveform profiles. ‘Daubechies’ 4 (db4) mother wavelet and four levels decomposition were implemented to extract the features. Approximation at level 4 (A4) and detail coefficient at level 1 to 4 (D1-D4) were extracted to evaluate the energy, skewness, and kurtosis. Based on the results, lightning showed the highest energy, skewness and kurtosis compared to the short circuit and switching voltage waveform. Therefore, these features can be utilized as the new parameters for fault detection in a power system network

scholarly journals Active Reduction of Short-Circuit Current in Power Distribution Systems

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 334
Author(s):  
Esteban Pulido ◽  
Luis Morán ◽  
Felipe Villarroel ◽  
José Silva
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Power Converter ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
In Series

In this paper, a new concept of short-circuit current (SCC) reduction for power distribution systems is presented and analyzed. Conventional fault current limiters (FCLs) are connected in series with a circuit breaker (CB) that is required to limit the short-circuit current. Instead, the proposed scheme consisted of the parallel connection of a current-controlled power converter to the same bus intended to reduce the amplitude of the short-circuit current. This power converter was controlled to absorb a percentage of the short-circuit current from the bus to reduce the amplitude of the short-circuit current. The proposed active short-circuit current reduction scheme was implemented with a cascaded H-bridge power converter and tested by simulation in a 13.2 kV industrial power distribution system for three-phase faults, showing the effectiveness of the short-circuit current attenuation in reducing the maximum current requirement in all circuit breakers connected to the same bus. The paper also presents the design characteristics of the power converter and its associated control scheme.

scholarly journals Probability-Based Customizable Modeling and Simulation of Protective Devices in Power Distribution Systems

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 199
Author(s):  
Chengwei Lei ◽  
Weisong Tian
Keyword(s):  
Power Systems ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Short Circuit ◽  
Current Data ◽  
System Level ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
Protective Devices

Fused contactors and thermal magnetic circuit breakers are commonly applied protective devices in power distribution systems to protect the circuits when short-circuit faults occur. A power distribution system may contain various makes and models of protective devices, as a result, customizable simulation models for protective devices are demanded to effectively conduct system-level reliable analyses. To build the models, thermal energy-based data analysis methodologies are first applied to the protective devices’ physical properties, based on the manufacturer’s time/current data sheet. The models are further enhanced by integrating probability tools to simulate uncertainties in real-world application facts, for example, fortuity, variance, and failure rate. The customizable models are expected to aid the system-level reliability analysis, especially for the microgrid power systems.

scholarly journals A Utilisation of Improved Gabor Transform for Harmonic Signals Detection and Classification Analysis

2017 ◽  
Vol 7 (1) ◽  
pp. 21
Author(s):  
M.H. Jopri ◽  
A.R. Abdullah ◽  
T. Sutikno ◽  
M. Manap ◽  
M.R. Yusoff
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Gabor Transform ◽  
Classification Analysis ◽  
Power Distribution System ◽  
Percent Correct ◽  
Time Frequency ◽  
Harmonic Signals ◽  
Threshold Setting

This paper presents a utilization of improved Gabor transform for harmonic signals detection and classification analysis in power distribution system.  The Gabor transform is one of time frequency distribution technique with a capability of representing signals in jointly time-frequency domain and known as time frequency representation (TFR). The estimation of spectral information can be obtained from TFR in order to identify the characteristics of the signals. The detection and classification of harmonic signals for 100 unique signals with numerous characteristic of harmonics with support of rule-based classifier and threshold setting that been referred to IEEE standard 1159 2009. The accuracy of proposed method is determined by using MAPE and the outcome demonstrate that the method gives high accuracy of harmonic signals classification. Additionally, Gabor transform also gives 100 percent correct classification of harmonic signals. It is verified that the proposed method is accurate and cost efficient in detecting and classifying harmonic signals in distribution system.

Study on Protection for Islanded Micro-Grid

2012 ◽  
Vol 614-615 ◽  
pp. 916-920
Author(s):  
Xue Ling Zhu ◽  
Fei Han ◽  
Jia Liu
Keyword(s):  
Distributed Generation ◽  
Power Distribution ◽  
Distribution System ◽  
Short Circuit ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Power Distribution System ◽  
Protection Strategy ◽  
Islanded Operation ◽  
Micro Grid

Technology of Micro-grid emerges, and power distribution system faults, allowing for the distributed generation keeping alive the islanded operation with the important load . But if the interior of Micro-grid happens a fault again, the short-circuit current of Micro-grid is so insufficient that traditional current protection can not play a part in the protection. In order to solve this problem, it introduced a new relay protection strategy, and provided the basis for the relay protection design of Micro-grid in the future.

scholarly journals Multifunctional Dynamic Voltage Restorer for Power Quality Improvement

2018 ◽  
Author(s):  
Dung Vo Tien ◽  
Radomir Gono ◽  
Zbigniew Leonowicz
Keyword(s):  
Power Quality ◽  
Power Distribution ◽  
Distribution System ◽  
Short Circuit ◽  
Operating Conditions ◽  
Dynamic Voltage Restorer ◽  
Efficient Operation ◽  
Power Distribution System ◽  
Voltage Restorer ◽  
Dynamic Voltage

Power quality is a major concern in electrical power systems. The power quality disturbances such as sags, swells, harmonic distortion and other interruptions have impact on the electrical devices and machines and in severe cases can cause serious damages. Therefore it is required to recognize and compensate all types of disturbances at an earliest to ensure normal and efficient operation of the power system. To solve these problems, many types of power devices are used. At the present time, one of those devices, Dynamic Voltage Restorer (DVR) is the most efficient and effective device used in power distribution system. In this paper, design and modeling of a new structure of multifunctional DVR for voltage correction is presented. The performance of the device under different conditions such as voltage swell, voltage sag due to symmetrical and unsymmetrical short circuit, starting of motors, and voltage distortion are described. Simulation result shows the superior capability of proposed DVR to improve power quality under different operating conditions. The proposed new DVR controller is able to detect the voltage disturbances and control the converter to inject appropriate voltages independently for each phase and compensate to load voltage through three single- phase transformers.

scholarly journals An Identification of Multiple Harmonic Sources in a Distribution System by Using Spectrogram

2018 ◽  
Vol 7 (2) ◽  
pp. 244-256
Author(s):  
M. H. Jopri ◽  
A. R. Abdullah ◽  
M. Manap ◽  
T. Sutikno ◽  
M. R. Ab Ghani
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Power Flow ◽  
Flow Direction ◽  
Correct Identification ◽  
Power Distribution System ◽  
Time Frequency ◽  
Frequency Representation ◽  
Identification Technique ◽  
Cost Efficient

The identification of multiple harmonic sources (MHS) is vital to identify the root causes and the mitigation technique for a harmonic disturbance. This paper introduces an identification technique of MHS in a power distribution system by using a time-frequency distribution (TFD) analysis known as a spectrogram. The spectrogram has advantages in term of its accuracy, a less complex algorithm, and use of low memory size compared to previous methods such as probabilistic and harmonic power flow direction. The identification of MHS is based on the significant relationship of spectral impedances, which are the fundamental impedance (Z1) and harmonic impedance (Zh) that estimate the time-frequency representation (TFR). To verify the performance of the proposed method, an IEEE test feeder with several different harmonic producing loads is simulated. It is shown that the suggested method is excellent with 100% correct identification of MHS. The method is accurate, fast and cost-efficient in the identification of MHS in power distribution arrangement.

scholarly journals A Method of DC Arc Detection in All-Electric Aircraft

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4190
Author(s):  
Teng Li ◽  
Zhijie Jiao ◽  
Lina Wang ◽  
Yong Mu
Keyword(s):  
Fault Detection ◽  
Real Time ◽  
Power Distribution ◽  
Distribution System ◽  
Detection Method ◽  
Discrete Wavelet ◽  
Power Distribution System ◽  
Time Frequency ◽  
Intelligent Recognition ◽  
Dc Arc

Arc faults in an aircraft’s power distribution system (PDS) often leads to cable and equipment damage, which seriously threatens the personal safety of the passengers and pilots. An accurate and real-time arc fault detection method is needed for the Solid-State Power Controller (SSPC), which is a key protection equipment in a PDS. In this paper, a new arc detection method is proposed based on the improved LeNet5 Convolutional Neural Network (CNN) model after a Time–Frequency Analysis (TFA) of the DC currents was obtained, which makes the arc detection more real-time. The CNN is proposed to detect the DC arc fault for its advantage in recognizing more time–frequency joint details in the signals; the new structure also combines the adaptive and multidimensional advantages of the TFA and image intelligent recognition. It is confirmed by experimental data that the combined TFA–CNN can distinguish arc faults accurately when the whole training database has been repeatedly trained 3 to 5 times. For the TFA, two kinds of methods were compared, the Short-Time Fourier Transform (STFT) and Discrete Wavelet Transform (DWT). The results show that DWT is more suitable for DC arc fault detection. The experimental results demonstrated the effectiveness of the proposed method.

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