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Review of Performance of Impedance Based and Travelling Wave Based Fault Location Algorithms in Double Circuit Transmission Lines
Ankamma Rao Jonnalagadda,
Gebreegziabher Hagos
Issue:
Volume 3, Issue 4, August 2015
Pages:
65-69
Received:
31 May 2015
Accepted:
10 June 2015
Published:
4 July 2015
Abstract: Parallel transmission lines or Double circuit transmission lines have been extensively utilized in modern power systems to enhance the reliability and security for transmission of electrical energy. This paper presents two fundamental algorithms: Impedance based, Travelling wave (TW) based algorithms for 100km, 400KV Double circuit transmission lines. MATLAB/ Simulink software was used to implement these algorithms. The accuracy of fault location on power transmission line are reviewed for these two methods by varying various parameters like fault type, fault location on a given power system model.
Abstract: Parallel transmission lines or Double circuit transmission lines have been extensively utilized in modern power systems to enhance the reliability and security for transmission of electrical energy. This paper presents two fundamental algorithms: Impedance based, Travelling wave (TW) based algorithms for 100km, 400KV Double circuit transmission lin...
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Study on Data Compression and Reduction of the Aviation Network Based on Multi-resolution Wavelet Analysis
Issue:
Volume 3, Issue 4, August 2015
Pages:
70-75
Received:
19 April 2015
Accepted:
29 June 2015
Published:
14 July 2015
Abstract: This paper proposes complex network data compression idea based on the multi-resolution wavelet decomposition theory, analyzes the concrete form of wavelet basis choice and wavelet decomposition, and then puts forward the determination method of network decomposition levels and parameters reduction method after decomposition. The empirical study shows that four-level wavelet decomposition for Chinese aviation network adjacency matrix is carried out by Haar wavelet basis, and the lowest frequency sub-band is matrix. Moreover, the average degree, the average shortest path length and clustering coefficient of original network are restored in the lowest frequency sub-band after decomposition.
Abstract: This paper proposes complex network data compression idea based on the multi-resolution wavelet decomposition theory, analyzes the concrete form of wavelet basis choice and wavelet decomposition, and then puts forward the determination method of network decomposition levels and parameters reduction method after decomposition. The empirical study sh...
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Enhanced EHD and Electrostatic Propulsion Devices Based on Polarization Effect Using Asymmetrical Metal Structure
Issue:
Volume 3, Issue 4, August 2015
Pages:
76-86
Received:
6 July 2015
Accepted:
18 July 2015
Published:
28 July 2015
Abstract: Electro hydro dynamic (EHD) and electrostatic propulsion devices were developed in the 1920s by Thomas Townsend Brown. One such device, called a “lifter”, has no moving parts and, in the air, operates on electrical energy. It is a fashionable device and has a very simple structure, basically consisting of a narrow wire electrode and a large, flat one. However, it has a low ratio of propulsion force to unit electrical input power. According to theory, the propulsion force it generates depends on the interaction between the ion density of the ionized air and the charges on the surface of the large electrode. EHD and electrostatic propulsion models using the polarization effect are proposed to improve the ratio of the propulsion force to unit electrical input power. The propulsion device generates propulsion force through the use of an asymmetrical metal structure with charges generated by the polarization effect. The propulsion force the new devices generated for the same electric energy was 5.7 times higher than that of a basic type lifter owing to additional propulsion force being generated by the maximum polarization effect in the experiments. It was found that combining other effects with this polarization effect results in the ratio of generated propulsion force to electric power being close to 100N/kW when the electric power is high. This value is as high as that of a helicopter. We also performed numerical analysis was also performed for capacitances and charges for various kinds of EHD and electrostatic propulsion devices. An optimized system was developed and is discussed in this paper.
Abstract: Electro hydro dynamic (EHD) and electrostatic propulsion devices were developed in the 1920s by Thomas Townsend Brown. One such device, called a “lifter”, has no moving parts and, in the air, operates on electrical energy. It is a fashionable device and has a very simple structure, basically consisting of a narrow wire electrode and a large, flat o...
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A Self-Adaptive DC/DC Buck Converter Control Modulation Design
Pengcheng Xu,
Zhigang Han
Issue:
Volume 3, Issue 4, August 2015
Pages:
87-92
Received:
14 July 2015
Accepted:
24 July 2015
Published:
3 August 2015
Abstract: DC/DC converter is widely used in many electronic application power supplies. Usually, in the previously DC/DC converter control modulation, the duty cycle can be changed according the feedback signal in pulse width modulation (PWM) or the frequency be changed with a constant ON time or OFF time in pulse frequency modulation (PFM). A self-adaptive DC/DC converter control modulation is proposed in this paper. Based on the outputs of two uniform operational transconductance amplifiers which are influenced by the feedback voltage, both of the pulse ON time and pulse OFF time will be changed simultaneously. A self-adaptive frequency can be achieved in this control modulation. It can get a same output voltage ripple with a lower control frequency.
Abstract: DC/DC converter is widely used in many electronic application power supplies. Usually, in the previously DC/DC converter control modulation, the duty cycle can be changed according the feedback signal in pulse width modulation (PWM) or the frequency be changed with a constant ON time or OFF time in pulse frequency modulation (PFM). A self-adaptive ...
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Dynamic Comparator with Using Negative Resistance and CMOS Input Pair Strategies in FS =4MHz-10GHz
M. Dashtbayazi,
M. Sabaghi,
S. Marjani
Issue:
Volume 3, Issue 4, August 2015
Pages:
93-96
Received:
15 March 2015
Accepted:
27 April 2015
Published:
13 August 2015
Abstract: A 4MHz-10GHz, 10ps/dec dynamic comparator with using negative resistance and CMOS input differential pair is proposed and designed in IBM 130nm CMOS process technology. In this design, we effort that taking maximum sampling frequency from CMOS technology and the proposed comparator consumes 110nw-146µW at 1.5V supply
