Wuhan Electrical Power Technical College

Wuhan, China

Wuhan Electrical Power Technical College

Wuhan, China
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Dai Y.,Wuhan University | Ren T.,Wuhan Electrical Power Technical College | Wang Y.,Wuhan Electrical Power Technical College | Zhang X.,Wuhan University
Gold Bulletin | Year: 2017

Gold nanoparticles (AuNPs) play an important role in catalytic reduction of 4-nitrophenol. To obtain highly dispersed and stable AuNPs, the stabilizer is required. In this work, core-shell-corona polymeric micelles prepared by self-assembly of the commercial ABC triblock polymer poly(ethylene oxide-b-2-vinyl pyridine-b-styrene) (abbreviated to PEO-b-P2VP-b-PS) were explored as an excellent stabilizer of AuNPs. PEO-b-P2VP-b-PS-stabilized AuNPs with the diameter of approximately 7 nm were prepared through chemical reduction of Au ions in aqueous medium at mild conditions. The preparation was environmentally friendly without using any organic solvents and suitable for commercial process without heat. PEO-b-P2VP-b-PS-stabilized AuNPs had high catalytic activity for chemical reduction of 4-nitrophenol. The results of stability and catalytic activity indicated that nitrogen atoms and triblock structure of PEO-b-P2VP-b-PS had synergistic effect on stabilizing AuNPs. © 2017, Springer International Publishing Switzerland.


Tang J.,Wuhan University of Technology | Tang J.,Nanjing Paneng Electrical Power Technology Co. | Yang C.,Wuhan Electrical Power Technical College | Cheng L.,Nanjing Paneng Electrical Power Technology Co.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2017

Zero-sequence current variation characteristics of faulty and healthy distribution feeders with different fault resistances and earth capacities during the changing process of residual current compensation factors are analyzed. Firstly, the relational expression for zero- sequence current is given. Secondly, zero-sequence current variation curves of distribution feeders are presented for multi-parameter scenarios with residual current compensation factor varying in over-compensation, under-compensation and whole regions. The results show that once single-line-to-ground fault through resistance occurs, the zero-sequence current variation characteristic of faulty feeder is consistent with that of healthy feeder under the following conditions: ①residual current compensation factor is less than zero but greater than the opposite number of the ratio of faulty feeder's ground capacitance to total ground capacitance of all feeders; ②fault resistance is greater than the boundary value which is inversely proportional to the ground capacitance of the feeder while the residual current compensation factor is greater than zero. The analysis results provide an important theoretical basis to the remnant current increment method. © 2017 Automation of Electric Power Systems Press.


Yang Y.,Wuhan Electrical Power Technical College
Advanced Materials Research | Year: 2013

GICs in technological conductor networks are a ground manifestation of space weather. During severe geomagnetic storms, if GICs flow in power systems, real and reactive power flow will swing abnormally, also transformer saturation, over-voltage fluctuation, frequency shift, unnecessary relay trippings and increased harmonic contents, even damage of transformer or a collapse of the whole system may occur. So GIC controlling in power systems is so significant that it can help power systems stand through strong geomagnetic disturbances, as well as ensure safe and stable operation of power systems. In this paper, control methods and techniques on GIC in power systems have been summarized in reference of research achievements and control experience on GIC. © (2013) Trans Tech Publications, Switzerland.


Fan Y.,Wuhan Electrical Power Technical College
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011 - Proceedings | Year: 2011

Process neural network (PNN) is a new neural network. This paper intends to improve the training speed of the discrete PNN with a Levenberg-Marquardt modified gradient training algorithm. The training steps and the algorithm are illustrated. Further, an experiment for the prediction of the humidity of sealed boxes is taken as a case study. This modified algorithm is employed in the case study where its fast convergence is convinced. © 2011 IEEE.


Fan Y.,Wuhan Electrical Power Technical College
IET Conference Publications | Year: 2014

The structural characteristics of one kind of the stress mode vortex flow meters was introduced for raising up its survey performance. According to elaborately expounding the vortex survey theory, the mathematical relation between the variations of vortex force and stress was studied. The mathematical model of vortex flow survey was established and simulated and the simulated results were carefully analyzed. Carrying out mathematical modeling and simulation to the stress mode vortex flow sensor can bring further comprehension to the system. And the method is effective to the design and consummation of the stress mode vortex flowmeter.


Yuan Y.,Wuhan Electrical Power Technical College | Qin Y.,Huazhong University of Science and Technology | Sun J.-Q.,Huazhong University of Science and Technology
Guangdianzi Jiguang/Journal of Optoelectronics Laser | Year: 2011

We propose and investigate a novel technique for the generation of millimeter-wave (mm-wave), i.e., frequency sixuplexing technique. The proposed technique adopts two cascaded Mach-Zehnder modulators (MZMs). The first MZM, biased at minimum transmission, is only used for the odd-order optical harmonic generation, and then by using a second MZM, biased at maximum transmission, all odd-order optical harmonics are suppressed. As an example, we consider a radio frequency (RF) at 10 GHz, which drives the MZMs; and a mm-wave signal at 60 GHz, i.e. a frequency sixupler, is obtained. The generated mm-wave signal is robust to fiber chromatic dispersion. The proposed technique is verified by experiments.


Yu H.,Changsha University of Science and Technology | Zhou R.-J.,Changsha University of Science and Technology | Han L.,Wuhan Electrical Power Technical College | Peng S.,Changsha University of Science and Technology | Zhang L.-M.,Hengyang County Electricity Bureau
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012

In order to cope with the impact of large-scale grid-connected wind farm on the stable operation of power systems, and analyze the economic benefit of grid-connected wind farm, a model of grid-connected wind farm which is established based on the risk measurements indicator of the Conditional Value-at-Risk (CVaR). The model considers the risk and random changes in wind speed and gets the solution through linear optimization. A benefit model of wind power considering all the benefit and cost of wind power comprehensively is established, and capacities of grid-connected wind farm and economic benefit in different wind speeds and risks are obtained. CVaR method, which avoids the tedious traditional method calculation with the method of Chance Constrained Programming, can easily calculate the capacity of grid-connected wind farm and get reliable economic benefits. Simulation is made on IEEE-14 bus system and the comparison results show that the proposed method is feasible.


Yuan Y.,Wuhan Electrical Power Technical College | Qin Y.,Huazhong University of Science and Technology
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2011

A novel technique for the generation of millimeter-wave (mm-wave), i.e., frequency sextupling technique, is theoretically analyzed and experimentally demonstrated. The proposed technique is comprised of two cascaded dual-electrode Mach-Zehnder modulators (MZMs). The first MZM, biased at the minimum transmission, is only used for odd-order optical harmonic generation, and then a second MZM, biased at the maximum transmission, suppresses all odd-order optical harmonics. As an example, a 10 GHz radio frequency (RF) signal, which drives the MZMs, is considered; and a mm-wave signal at 60 GHz, i.e., a frequency sextupler, is obtained. Compared with the conventional techniques without optical band-pass filter, the generated mm-wave signal is robust to fiber chromatic dispersion. The proposed technique is verified by experiments.


Zheng X.-Y.,Wuhan University | Ding J.-Y.,Wuhan University | Huang N.,Wuhan Electrical Power Technical College
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

In order to advance the reliability and accuracy of one-terminal fault location for transmission lines, an impedance-traveling wave assembled algorithm, which combines measurement impedance method with traveling wave method, is presented. It uses method based on measurement impedance to calculate roughly fault distance. Then, time regions of reflected waves from fault point and opposite bus to detective bus are confirmed respectively through the distance. Finally, exact time of reflected wave from fault point and that of reflected wave from opposite bus to detective bus are identified respectively in corresponding regions, and fault location is implemented according to the results detected. It has complementarities of both methods, because measurement impedance method guarantees reliability and traveling wave method improves accuracy. The simulation has proved that the assembled algorithm proposed is correct.


Wang P.,Wuhan Electrical Power Technical College | Wang P.,Wuhan University | Liu F.,Wuhan University | Zha X.,Wuhan University
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2013

A design of output LCL filter based on shunt APF with active damping is proposed. It selects the total inductance with the consideration of current tracking rapidity, allowable maximum current ripple, etc. and sets the upper limit of capacitance by the loss of fundamental reactive power, based on which, the L1 and L2 of total inductance and the capacitance are selected with the consideration of switching harmonic current decay rate and the constraint of resonant frequency. The active damping method based on capacitor current feedback is applied to avoid the LCL filter resonance and the feedback factor is designed to effectively suppress the suborder harmonic vibration. The shunt APF with repetitive learning control strategy is simulated with PSCAD and results show its superiority and effectiveness.

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