The number of chained π-type circuits for dynamic analogy of half-wavelength transmission line considering short-circuit fault

2017 ◽  
Author(s):  
Yurong Li ◽  
Chongqing Jiao ◽  
Bei Wang
Keyword(s):  
Transmission Line ◽  
Short Circuit ◽  
Half Wavelength ◽  
Short Circuit Fault

scholarly journals An improved Bergeron differential protection for half-wavelength AC transmission line

2021 ◽  
Vol 257 ◽  
pp. 01016
Author(s):  
Pengfei Shao ◽  
Yu Li ◽  
Ruiming Fang ◽  
Xinghua Guo
Keyword(s):  
Transmission Line ◽  
Short Circuit ◽  
Differential Protection ◽  
Protection Scheme ◽  
Transmission Distance ◽  
Half Wavelength ◽  
Current Differential Protection ◽  
And Performance ◽  
Ac Transmission ◽  
Short Circuit Fault

Half-wavelength AC transmission line has the characteristics of long transmission distance and high voltage level, and its fault characteristics are significantly different from conventional transmission line. In order to reduce the interference of distributed capacitive current on half-wavelength AC transmission line on the calculation of current differential protection, this paper proposes a new current differential protection scheme based on Bergeron model. In order to solve the problem of small differential current located at the midpoint when a short circuit fault occurs, a solution using different methods to calculate setting value in different areas is proposed. The protection can move quickly near the terminal and delay to act in the middle area. After simulation and verification on the PSCAD experimental platform, it is found that when there is a fault at both terminals of the line, the protection can quickly operate in about 10 ms; when fault occurs in the middle area, the protection can delay its operation. The experimental results show that the various actions and performance of the protection device can meet the requirements of safe operation of half-wavelength transmission line.

scholarly journals Study on the Power-Frequency Waves Distribution Characteristics for Half-Wavelength Transmission Lines Based on the Frequency-Length Factor

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Chang Chen ◽  
Xiaoyang Ma ◽  
Honggeng Yang ◽  
Weikang Wang ◽  
Yilu Liu
Keyword(s):  
Transmission Lines ◽  
Short Circuit ◽  
Distribution Characteristics ◽  
System Parameters ◽  
Frequency Resonance ◽  
Fault Resistance ◽  
Maximum Value ◽  
Half Wavelength ◽  
Power Frequency ◽  
Short Circuit Fault

To analyze the distribution characteristics of voltage and current along half-wavelength transmission lines (HWTLs) in the cases with or without short circuit in the steady state, the method based on the frequency-length factor (FLF) for lossy lines is proposed. Firstly, according to the pole condition of the FLF, the distribution characteristics of power-frequency waves along HWTLs are analyzed. Then, the comprehensive effects of the system parameters and fault resistance are explored, revealing the mechanism of the power-frequency resonance caused by nonmetallic short circuit. Meanwhile, unbalanced short-circuit fault is studied by exploiting additional impedance. The results show that the distribution of the maximum value of power-frequency resonance voltage is related to the system parameters but not to the fault impedance. When a HWTL is short circuited at 2640 km∼2930 km, the resonance voltage can reach to 21 p.u. In relation to symmetrical short circuit, the resonance voltage appears at 1469 km from the short-circuit point, while the position moves towards the short-circuit point with the increase of additional impedance in asymmetrical short-circuit conditions. Additionally, the model theoretically proves that the power-frequency overvoltage induced by short circuit does not appear on a line whose length is less than 1469 km. Finally, cases are studied on PSCAD to verify the accuracy of the model.

An Intelligent Short-Circuit Fault Classification Scheme for Power Transmission Line

2021 ◽  
Author(s):  
Md. Sihab Uddin ◽  
Erphan Bhuiyan ◽  
Subrata Sarker ◽  
Sajal Das ◽  
Niloy Sarker ◽  
...  
Keyword(s):  
Transmission Line ◽  
Classification Scheme ◽  
Power Transmission ◽  
Short Circuit ◽  
Fault Classification ◽  
Power Transmission Line ◽  
Short Circuit Fault

scholarly journals Study of Inertia and Damping Characteristics of Doubly Fed Induction Generators and Improved Additional Frequency Control Strategy

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 38 ◽  
Author(s):  
Xiangwu Yan ◽  
Zijun Song ◽  
Yun Xu ◽  
Ying Sun ◽  
Ziheng Wang ◽  
...  
Keyword(s):  
Transmission Line ◽  
Control Strategy ◽  
Frequency Control ◽  
Short Circuit ◽  
Wind Farms ◽  
Frequency Fluctuation ◽  
Whole Process ◽  
Damping Characteristics ◽  
Doubly Fed ◽  
Short Circuit Fault

Large-scale wind farms connect to the grid and deliver electrical energy to the load center. When a short-circuit fault occurs on the transmission line, there will be an excess of electric power, but the power demand will increase instantaneously once the fault is removed. The conventional additional frequency control strategies of wind farms can effectively reduce the frequency fluctuation caused by load mutation, but still there are some limitations for the frequency fluctuation caused by the whole process of occurrence, development and removal of a short-circuit fault on the transmission line. Therefore, this paper presents an improved additional frequency control strategy for wind farms. According to the variation law of system frequency during the whole process of a short-circuit fault, the proposed strategy revises the parameters in conventional additional frequency control of the doubly-fed induction generator (DFIG) to have effective damping characteristics throughout the entire process from failure to removal, thereby the output power of DFIGs could respond to frequency fluctuation rapidly. MATLAB/ Simulink is used to build a four-machine two-area model for simulation analysis. The results show that the control strategy can effectively reduce the frequency fluctuation of DFIGs, and enhance the stability of the system.

scholarly journals Development of a Converter-Based Transmission Line Emulator With Three-Phase Short-Circuit Fault Emulation Capability

2018 ◽  
Vol 33 (12) ◽  
pp. 10215-10228 ◽  
Author(s):  
Shuoting Zhang ◽  
Bo Liu ◽  
Sheng Zheng ◽  
Yiwei Ma ◽  
Fei Wang ◽  
...  
Keyword(s):  
Transmission Line ◽  
Short Circuit ◽  
Three Phase ◽  
Short Circuit Fault ◽  
Fault Emulation
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