The study on the effects of the transformer Δ-side unbalanced third harmonic on the parallel capacitor bank caused by the sympathetic inrush current and the countermearsures

2015 ◽  
Author(s):  
Wang Ye ◽  
Yuan Yubo ◽  
Lu Yuping ◽  
Kong Xiangping ◽  
Qian Jiabin ◽  
...  
Keyword(s):  
Capacitor Bank ◽  
Inrush Current ◽  
Third Harmonic ◽  
Parallel Capacitor

New Method to Identify Transformer Inrush Current Based on FFT and SVM

2013 ◽  
Vol 313-314 ◽  
pp. 887-890
Author(s):  
Mao Fa Gong ◽  
Guo Liang Li ◽  
Wen Hua Xia ◽  
Hong Lin Yan ◽  
Jing Wen Qu ◽  
...  
Keyword(s):  
Cross Validation ◽  
Accurate Method ◽  
High Accuracy ◽  
Generation Mechanism ◽  
New Method ◽  
Inrush Current ◽  
Fault Current ◽  
Third Harmonic ◽  
Internal Fault ◽  
Three Phase

To improve transformer longitudinal differential protections reliability, this paper deeply analyzes generation mechanism and characteristic of transformer inrush current, and uses PSCAD/EMTDC software to simulate 188 kinds of transformer operation states. They are including internal fault current, inrush current and no-load closing with internal fault. On the background of those simulations, it proposes a simple and accurate method to identify inrush current based on SVM. SVM selects Gaussion Kernel, and takes three-phase differential current, fundamental, secondary harmonic and third harmonic as characteristic quantities. Many cross-validation results verify that the training SVM has high accuracy. This method can identify inrush current and internal fault current (including no-load closing with internal fault current) rapidly and accurately. It takes less time, and is easy to perform.

scholarly journals Simulation study and experimental results for detection and classification of the transient capacitor inrush current using discrete wavelet transform and artificial intelligence

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 93-104 ◽  
Author(s):  
Theerasak Patcharoen ◽  
Suntiti Yoomak ◽  
Atthapol Ngaopitakkul ◽  
Chaichan Pothisarn
Keyword(s):  
Artificial Intelligence ◽  
Simulation Study ◽  
Wavelet Transforms ◽  
Fuzzy Inference ◽  
Capacitor Bank ◽  
Experimental Results ◽  
Discrete Wavelet ◽  
Inrush Current ◽  
Discrete Wavelet Transforms ◽  
Inference System

Abstract This paper describes the combination of discrete wavelet transforms (DWT) and artificial intelligence (AI), which are efficient techniques to identify the type of inrush current, analyze the origin and possible cause on the capacitor bank switching. The experiment setup used to verify the proposed techniques can be detected and classified the transient inrush current from normal capacitor rated current. The discrete wavelet transforms are used to detect and classify the inrush current. Then, output from wavelet is acted as input of fuzzy inference system for discriminating the type of switching transient inrush current. The proposed technique shows enhanced performance with a discrimination accuracy of 90.57%. Both simulation study and experimental results are quite satisfactory with providing the high accuracy and reliability which can be developed and implemented into a numerical overcurrent (50/51) and unbalanced current (60C) protection relay for an application of shunt capacitor bank protection in the future.

Electrical Stress Analysis of Switching Transients in 115 kV High Voltage Substation

2015 ◽  
Vol 781 ◽  
pp. 333-336
Author(s):  
Ratana Kem ◽  
Warunee Srisongkram ◽  
Phanupong Fuangpian ◽  
Thanapong Suwanasri
Keyword(s):  
Stress Analysis ◽  
Capacitor Bank ◽  
Circuit Breaker ◽  
Inrush Current ◽  
Circuit Breakers ◽  
Power Circuit ◽  
Electrical Stress ◽  
Transient Recovery Voltage ◽  
Recovery Voltage

This paper presents electrical stress analysis from capacitor bank switching in a 115 kV substation. The actual data of all equipment in substation are used in the simulated circuit by using ATP/EMTP program. The cases study focused on the determination of proper value of series reactor, effect of circuit breaker pole discrepancy on inrush current, line model selection and load variation. Electrical stress from energizing inrush current as well as transient recovery voltage and rate of rise of recovery voltage imposed on power circuit breaker during capacitor bank has been analyzed. The obtained results are used as guidelines for analysis of the electric stresses on substation equipment while capacitor banks are energized. Moreover, those results can be used to select the proper rating of circuit breakers to withstand the electric stresses in the transmission network.

Study of Capacitor Bank Fault Location

2013 ◽  
Vol 385-386 ◽  
pp. 1213-1215
Author(s):  
Tao Zhao ◽  
Yi Fan Liao ◽  
Zhi Ming Su ◽  
Rui Hai Li ◽  
Yun Peng Liu
Keyword(s):  
Measurement Error ◽  
Internal Structure ◽  
Fault Location ◽  
Capacitor Bank ◽  
Operation Mode ◽  
Complex Environments ◽  
Film Capacitor ◽  
Parallel Capacitor ◽  
Status Information ◽  
Sensor Accuracy

At present, the operational parallel compensating capacitors can only through the protection action for the information, so we can‘t location the fault capacitor. In order to obtain every parallel capacitor running status information and according to internal structure and the operation mode of film capacitor, this paper proposed a method of locating a capacitor, which can eliminate the affection caused by the environment and measurement error of sensor accuracy effectively. So we can locate the fault capacitor in complex environments running on the site.

scholarly journals Design and Realization of Intelligent Phase-controlled System for Permanent Magnetic Actuator of AC Contactor

2020 ◽  
Vol 165 ◽  
pp. 06019
Author(s):  
Chen Ya bin ◽  
Zhang Zhen tao ◽  
Li Qiang ◽  
Zou Ping Guo
Keyword(s):  
Control System ◽  
Phase Angle ◽  
Capacitor Bank ◽  
Inrush Current ◽  
Magnetic Actuator ◽  
Phase Selection ◽  
Intelligence System ◽  
Permanent Magnetic Actuator ◽  
Performance Requirements ◽  
System A

When the AC contactor switches the capacitor bank, the phase angle of the power grid is random, so the electromagnetic transient process will generate large inrush current and overvoltage, causing large disturbance to the power system. A set of AC contactor with permanent magnetic actuator (PMA) and its intelligent phase selection control system are designed to solve this problem. Firstly, the PMA is designed. The dynamic characteristics of the actuator are simulated and analyzed in ANSOFT to meet the performance requirements of phase selection control. Then the principle of phase selection control and the strategy of switching capacitor bank are analyzed. Based on this, the software and hardware of intelligent phase selection control system are designed, including phase selection control module, IGBT driver module and coil discharge module. Finally, the experimental verification is carried out on the designed AC contactor. The test results show that the phase selection errors of the designed intelligence system are within 1°, and the contactor closing and opening time deviations are within 0.5ms, which means the system can effectively realize the closing and opening control at the specified phase angle.

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