Analysis and calculation of electromagnetic force under two-phase short-circuit fault of high voltage asynchronous motor

2011 ◽  
Author(s):  
Liang Yan-ping ◽  
Yao Qing-shuang ◽  
Liu Jin-peng
Keyword(s):  
High Voltage ◽  
Electromagnetic Force ◽  
Short Circuit ◽  
Asynchronous Motor ◽  
Two Phase ◽  
Short Circuit Fault

scholarly journals Symmetrical Loss of Excitation Fault Diagnosis in an Asynchronized High-Voltage Generator

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3054 ◽  
Author(s):  
Yanling Lv ◽  
Yuting Gao ◽  
Jian Zhang ◽  
Chenmin Deng ◽  
Shiqiang Hou
Keyword(s):  
Neural Network ◽  
Fault Diagnosis ◽  
High Voltage ◽  
Short Circuit ◽  
Open Circuit ◽  
Voltage Generator ◽  
Three Phase ◽  
Circuit Loss ◽  
High Voltage Generator ◽  
Short Circuit Fault

As a new type of generator, an asynchronized high-voltage generator has the characteristics of an asynchronous generator and high voltage generator. The effect of the loss of an excitation fault for an asynchronized high-voltage generator and its fault diagnosis technique are still in the research stage. Firstly, a finite element model of the asynchronized high-voltage generator considering the field-circuit-movement coupling is established. Secondly, the three phase short-circuit loss of excitation fault, three phase open-circuit loss of excitation fault, and three phase short-circuit fault on the stator side are analyzed by the simulation method that is applied abroad at present. The fault phenomenon under the stator three phase short-circuit fault is similar to that under the three phase short-circuit loss of excitation. Then, a symmetrical loss of the excitation fault diagnosis system based on wavelet packet analysis and the Back Propagation neural network (BP neural network) is established. At last, we confirm that this system can eliminate the interference of the stator three phase short-circuit fault, accurately diagnose the symmetrical loss of the excitation fault, and judge the type of symmetrical loss of the excitation fault. It saves time to find the fault cause and improves the stability of system operation.

scholarly journals Shafting Torsional Vibration Analysis of 1000 MW Unit under Electrical Short-Circuit Fault

2021 ◽  
Vol 11 (19) ◽  
pp. 9205
Author(s):  
Honggang Pan ◽  
Yunshi Wu ◽  
Zhiyuan Pang ◽  
Yanming Fu ◽  
Tianyu Zhao
Keyword(s):  
Short Circuit ◽  
Power Grid ◽  
Two Phase ◽  
Shaft System ◽  
Three Phase ◽  
Speed Fluctuation ◽  
Grid Side ◽  
Generator Terminal ◽  
The Impact ◽  
Short Circuit Fault

Taking a 1000 MW turbine generator as the research object, the short-circuit fault in electrical disturbance is analyzed. Since it is very difficult to carry out fault analysis experiments and research on actual systems, simulation analysis is one of the more effective means of electrical fault diagnosis; the simulation’s results approach the actual behavior of the system and are ideal tools for power system analysis, and can provide an empirical basis for practical applications. The short-circuit fault model of the SIMULINK power system is built to analyze the two types of faults of generator terminals short-circuit and power grid short-circuit. The impact load spectrum, fault current and speed fluctuation between low-voltage rotors were extracted and analyzed. The conclusion is that the impact value of electromagnetic torque at the generator terminal is greater than that on the power grid side. The impact value of a two-phase short-circuit at the generator terminal is the largest, and that of a three-phase short-circuit on the power grid side is the smallest. The transient impulse current of a three-phase short-circuit at any fault point is greater than that of a two-phase short-circuit; the impulse current of the grid side short-circuit is much greater than that of the generator terminal short-circuit; the speed fluctuation and fluctuation difference caused by the three-phase short-circuit in the grid side are the largest. The alternating frequency of the transient electromagnetic force of the four kinds of faults avoids the natural frequency of the torsional vibration of the shaft system, and the torsional resonance of the shaft system in the time domain of the short-circuit fault will not appear. However, after the fault is removed, the residual small fluctuation torque in the system has a potential impact on the rotor system. This research shows an analysis of the structural integrity and safe operation of turbine generator units after a short-circuit fault, which can not only be applied to engineering practice, but also provide a theoretical basis for subsequent research.

Impact of Rotor Inter-Turn Short-Circuit on Generator Rotor Force

2011 ◽  
Vol 143-144 ◽  
pp. 125-131 ◽  
Author(s):  
Yong Gang Li ◽  
Guo Wei Zhou ◽  
Yu Ca Wu ◽  
He Ming Li
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Force ◽  
Short Circuit ◽  
Total Force ◽  
Distribution Law ◽  
Generator Rotor ◽  
Finite Element Software ◽  
Full Force ◽  
Rotor Winding ◽  
Short Circuit Fault

This paper analyzes the calculation method of unbalanced electromagnetic force by rotor winding inter-turn short-circuit fault, analytical calculating method neglects saturation, cogging and other factors, so the calculation accuracy is not high, in order to accurately calculate the magnetic field and the unbalanced electromagnetic force, this paper propose to analyze generator magnetic field by a finite element software Ansys, the obtained magnetic field data are further used to analyze the distributed electromagnetic force and the total force that generator rotor suffered, electromagnetic force distribution law of different slots, different levels of inter-turn short-circuit are got, which provide a basis for further studying the full force on generator rotor.

Study on Preventing Override Trip System for High-Voltage Power Grid of Coal Mine Underground Based on the EtherCAT

2013 ◽  
Vol 273 ◽  
pp. 389-393
Author(s):  
Yu Mei Wang ◽  
Xu Yang ◽  
Hao Zhang
Keyword(s):  
High Voltage ◽  
Coal Mine ◽  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Power Grid ◽  
Supply System ◽  
Quality Requirements ◽  
Master Station ◽  
Short Circuit Fault

When the power supply system for coal mine underground take place a short circuit fault, multilevel switch often respond at the same time. And the existing comprehensive protector cannot satisfy the real-time and rapid quality requirements of preventing override trip system for high-voltage power grid of coal mine underground. So this paper put forward the research for comprehensive protector of preventing override trip based on the EtherCAT. This paper first analyzes the principle and characteristics of the EtherCAT technology; and then puts forward the overall scheme of preventing override trip system; Finally, study and design the slave station and master station of preventing override trip system based on the EtherCAT.

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