scholarly journals Investigation on the Influence of Gas Pressure on CO2 Arc Characteristics in High-Voltage Gas Circuit Breakers

2017 ◽  
Vol 4 (1) ◽  
pp. 95-98
Author(s):  
Z. Guo ◽  
X. Li ◽  
Y. Zhang ◽  
X. Guo ◽  
J. Xiong

CO<sub>2</sub> is identified as a promising alternative gas of SF<sub>6</sub>. The magnetohydrodynamics (MHD) arc model is established for a CO<sub>2</sub> circuit breaker. The influence of gas pressure is studied. The simulations are carried out for 0.5 MPa, 0.7 MPa and 0.9 MPa absolute filling pressure, allowing predictions of pressure and temperature distributions. The arc time constant θ and the power loss coefficient <em>Q</em> is extracted. The thermal interruption capability is estimated to grow with increasing filling pressure.

Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1204
Author(s):  
Gul Ahmad Ludin ◽  
Mohammad Amin Amin ◽  
Hidehito Matayoshi ◽  
Shriram S. Rangarajan ◽  
Ashraf M. Hemeida ◽  
...  

This paper proposes a new and surge-less solid-state direct current (DC) circuit breaker in a high-voltage direct current (HVDC) transmission system to clear the short-circuit fault. The main purpose is the fast interruption and surge-voltage and over-current suppression capability analysis of the breaker during the fault. The breaker is equipped with series insulated-gate bipolar transistor (IGBT) switches to mitigate the stress of high voltage on the switches. Instead of conventional metal oxide varistor (MOV), the resistance–capacitance freewheeling diodes branch is used to bypass the high fault current and repress the over-voltage across the circuit breaker. The topology and different operation modes of the proposed breaker are discussed. In addition, to verify the effectiveness of the proposed circuit breaker, it is compared with two other types of surge-less solid-state DC circuit breakers in terms of surge-voltage and over-current suppression. For this purpose, MATLAB Simulink simulation software is used. The system is designed for the transmission of 20 MW power over a 120 km distance where the voltage of the transmission line is 220 kV. The results show that the fault current is interrupted in a very short time and the surge-voltage and over-current across the proposed breaker are considerably reduced compared to other topologies.


1992 ◽  
Vol 7 (2) ◽  
pp. 1016-1022 ◽  
Author(s):  
L. van der Sluis ◽  
W.R. Rutgers ◽  
C.G.A. Koreman

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Viorel Nicolau

Many oil-based high-voltage circuit breakers are still in use in national power networks of developing countries, like those in Eastern Europe. Changing these breakers with new more reliable ones is not an easy task, due to their implementing costs. The acting device, called oleo-pneumatic mechanism (MOP), presents the highest fault rate from all components of circuit breaker. Therefore, online predictive diagnosis and early detection of the MOP fault tendencies are very important for their good functioning state. In this paper, fuzzy logic approach is used for the diagnosis of MOP-type drive mechanisms. Expert rules are generated to estimate the MOP functioning state, and a fuzzy system is proposed for predictive diagnosis. The fuzzy inputs give information about the number of starts and time of functioning per hour, in terms of short-term components, and their mean values. Several fuzzy systems were generated, using different sets of membership functions and rule bases, and their output performances are studied. Simulation results are presented based on an input data set, which contains hourly records of operating points for a time horizon of five years. The fuzzy systems work well, making an early detection of the MOP fault tendencies.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Hongkui Yan ◽  
Xin Lin ◽  
Jianyuan Xu

In this article, we take a 126 kV single-break vacuum circuit breaker as the research object and study the application of high-energy-density PM motor in the high-voltage circuit breaker for the first time. The PM motor maintains maximum power density and torque density during the start-up phase. Note that most of the faults of high-voltage circuit breakers are mechanical faults. We designed a set of mechanical fault prediction systems for high-voltage circuit breakers. We present the prediction method of the opening and closing action curve of the high-voltage circuit breaker. It is inspired by Chaos Ant Colony Algorithm (CAS) and an optimized Long- and Short-Term Memory (LSTM) cycle neural network. We constructed the main structure of the neural network expert system and established the fault prediction model of the high-voltage circuit breaker, based on the LSTM cycle neural network, optimized by CAS. We used the improved least-square method to achieve the operation accuracy of the phase control switch. Finally, we completed the development and experiment of the prototype.


2021 ◽  
Vol 261 ◽  
pp. 01014
Author(s):  
Yi Su ◽  
Yufeng Lu ◽  
Lei Zhang ◽  
Xiajin Rao

High voltage circuit breakers are important protection and control equipment for the power grid. The defects and faults of the circuit breaker seriously affect the safety and stability of the power system. As the key component of the operating mechanism of the circuit breaker, the opening/closing coils contain a large amount of information about the operating status of the mechanism. In order to investigate the cause of the difference in the current waveforms, this paper analyzes the factors affecting the circuit breaker opening/closing coil current based on the actual high voltage circuit breaker, and distinguishes the characteristics of the current caused by the environmental difference and Structural difference. At the same time, the characteristics of coil current changes under four different types of mechanism defects are analyzed. These results lay the foundation for status evaluation of high voltage circuit breakers based on opening/closing coil current.


2014 ◽  
Vol 687-691 ◽  
pp. 1054-1057 ◽  
Author(s):  
Xian Ping Zhao ◽  
Zhi Wan Cheng ◽  
Xiang Yu Tan ◽  
Wei Hua Niu

High voltage circuit breaker is one of the most significant devices and its health status will impact security of the power system. In this paper, the method of high voltage circuit breakers mechanical fault diagnosis is discussed, fault diagnosis method based on vibration signal is proposed. Firstly, the collected acoustic signals are proceed by blind source separation processing through fast independent component analysis. Then, the acoustic signal feature vector is extracted by improved ensemble empirical mode decomposition (EEMD) and the residual signal is filtered by fractional differential. Finally, the feature vectors are input into support vector machine (SVM) for fault diagnosis. Experiment shows that the proposed method can get more precise fault classification to high voltage circuit breakers.


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