Kaifeng Power Supply Company

Kaifeng, China

Kaifeng Power Supply Company

Kaifeng, China
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Bai C.,Kaifeng Power Supply Company | Zhu Y.,China Institute of Technology | Zhou D.,Kaifeng Power Supply Company | Niu H.,Kaifeng Power Supply Company
Advanced Materials Research | Year: 2011

With high effective screen-printing process, the diode field emission display (FED) panel was fabricated. The soda-lime flat glass was used as panel anode plate, and the indium tin oxide film covered on the anode plate surface was etched, which was used to form the anode electrodes. With simple screen printing method, the phosphor paste was prepared on the exposed anode electrode surface, so the phosphor dots were fabricated. Using insulation slurry as material, the insulation layer was also fabricated on the anode plate. The fabricated FED panel with carbon nanotube field emitters possessed good field emission characteristics and image displaying performance. © (2011) Trans Tech Publications, Switzerland.

Zhu Y.,China Institute of Technology | Bai C.,Kaifeng Power Supply Company | Zhou D.,Kaifeng Power Supply Company | Wang Q.,Kaifeng Power Supply Company
Advanced Materials Research | Year: 2011

Using carbon nanotube as field emitter, the field emission display (FED) panel with rectangular luminous layer was fabricated. The etched indium tin oxide (ITO) film was used as the ITO electrodes, and the phosphor powder was prepared to form the phosphor layer, so the rectangular luminous layer was fabricated on the anode back plane. In one anode pixel, the three anode sub-pixels would be included, which would reside on the same ITO electrode surface. The insulation layer would separate the adjacent anode sub-pixels and the adjacent ITO electrode, and the fabricated anode extension line was mainly used to reduce the excessive voltage drop. The FED panel with rectangular luminous layer possessed good field emission characteristic and high image brightness. © (2011) Trans Tech Publications, Switzerland.

Xu B.,Shanghai JiaoTong University | Zhang J.,Shanghai JiaoTong University | Cai X.,Shanghai JiaoTong University | Guan S.,Henan Electric Power Research Institute | Yao Y.,Kaifeng Power Supply Company
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2011

When a single-line-to-ground fault happens in the power grid, it is complex and difficult to determine the ground phase especially in the case of an unsymmetrical voltage and a large transition resistance. And the unsymmetrical voltage is often ignored because of simplified analyses in the previous literature. In this paper, with these factors considered a detailed analysis of the single-line-to-ground fault and the phasor diagram of the line-to-neutral voltages are presented firstly. It is concluded that the trajectory of the neutral voltage is no longer a semi-circular, but a circular arc. What is worse, in some cases it is not suitable to apply the traditional criterions that the previous literature proposed. A new method of constructing three new "phase" vectors is presented to identify the ground phase. Theoretical analyses and simulations show that the method can overcome the shortcomings of traditional methods and determine the grounding phase accurately.

Wang S.-H.,Henan Electric Power Company | Peng X.-Y.,Kaifeng Power Supply Company | Han X.,Henan Electric Power Company | Lu S.-H.,Kaifeng Power Supply Company | Song J.-J.,Xiuwu County Electrical Power Bureau
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

To meet the new requirement of direct-current power supply system in the <>, some problems arised in large-scale DC power system retrofit are analyzed and solved. In regard to the problem of polarity reversed when changing the circuit breaker of alternating current to the circuit breaker of direct current in DC power supply system, through the understanding of configuration of direct current's circuit breaker and arc extinction theory, acceptable connection method is found. For the problem of switch from looply connected to divergently connected power supply in DC power supply system's load network, three load network transformation proposals are put forward with advantages and disadvantages analysis. In DC power supply system, aiming at the problem of range coordination and model selection using parameters, also using practical tested figures on site, referencable advice is given to circuit breaker's capacity configuration.

Xu M.,Zhengzhou University | Yang Y.,Zhengzhou University | Zhang M.-Z.,Zhengzhou University | Dong Q.-F.,Mianchi Electrical Power Bureau | Bai C.-T.,Kaifeng Power Supply Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

An interpolated FFT algorithm based on the trinomial cosine exact Blackman window is proposed. This paper first discusses the frequency response of the exact Blackman window, then derives the formulas of interpolated FFT algorithm based on the exact Blackman window in detail. The cubic spline function is used to calculate correction factors for frequency and complex amplitude. Simulation results demonstrate that by using the cubic spline function, the amplitude error is less than 0.1%, the frequency error is less than 0.01 Hz, and the phase error is less than 5%. The new interpolated FFT algorithm proposed in this paper can effectively enhance the measuring accuracy of power system harmonics. It has a good real-time performance with less calculations compared with other interpolated FFT algorithms based on quadrinomial cosine window.

Gao F.L.,Kaifeng Power Supply Enterprise | Fang Y.W.,China Communications Construction Company Ltd.
Applied Mechanics and Materials | Year: 2014

According to the case that mass concrete in solid sections of lower pylon column of Jiashao Bridge was easy to crack in construction because of the bigger section size, larger content of cementitious material and lower water binder ratio, the temperature and thermal stresses distribution of mass concrete was simulated and temperature control scheme was adjusted constantly based on the results of field temperature monitoring. Through taking some temperature control measures such as applying circulating cooling water and prolonging the time appropriately, thermal insulation and moisture retention curing, extending the form removal time and controlling the quality of concrete, harmful cracks did not appear in solid sections of lower pylon column of Jiashao Bridge and anticipated temperature control requirements were achieved. © (2014) Trans Tech Publications, Switzerland.

Zhao J.-J.,Henan University | Hu W.-W.,Henan University | Gu X.-G.,Henan University | Yang P.,Kaifeng Power Supply Company
2011 3rd International Workshop on Intelligent Systems and Applications, ISA 2011 - Proceedings | Year: 2011

In this paper, An algorithm which uses an improved threshold algorithm in the de-noising of electricity signals and then extracted the fault feature by db10 wavelet, is proposed because of the features in the fault of high voltage electric power measurement system. Experiment results show that it is more efficient to de-noising by the improved threshold algorithm in wavelet analysis. The method in the diagnosis of fault of electric power measurement is very practical valuable. © 2011 IEEE.

Yun W.,Zhongyuan University of Technology | Ying X.,Zhongyuan University of Technology | Sheng Z.,Zhongyuan University of Technology | Ming X.,Zhongyuan University of Technology | Xue H.,Kaifeng Power Supply Company
Advanced Materials Research | Year: 2012

A MPPT (Maximum Power Point Tracking) control method of PV (Photovoltaic) generation system is proposed based on the shortcoming of the existing MPPT algorithms. The method applies CVT (Constant Voltage Tracking) algorithm to adjust the working point of PV array near the MPP (Maximum Power Point) for fast tracking when working point is far from MPP, and uses adapting duty cycle perturb method to optimize the steady state characteristic of MPP for effectively eliminate the output power oscillation under the setting precision. Its model is established and simulated with Matlab/Simulink. The CVT, duty cycle method and proposed methods are simulated respectively and simulation results show that, the proposed method tracks the MPP exactly and quickly and improves the energy conversion efficiency of PV generation system by eliminate the output power oscillation around MPP. Its fast response speed improves the static and dynamic performance of photovoltaic power system.

Du M.,Kaifeng Power Supply Company | Wang J.,Kaifeng Power Supply Company
2010 China International Conference on Electricity Distribution, CICED 2010 | Year: 2010

As the finish of national distribution network updating, the national distribution network situation is going to be better. There are more single phase grounding faults than interphase short circuit faults. But the general used current protection equipment, which only reflects the interphase short circuit, cannot reflect grounding fault. And the distribution network is getting more complex. So the currency protection,which is affected by operating mode, cannot cater the selectivity and sensitivity requirement of protection. The updated distance protection can not only reflect the grounding fault in distribution network but also would not be affected by the system operating mode. So it can cater the selectivity and sensitivity requirement of protection very well. And it makes the city distribution network more reliable. © 2010 Chinese Soc for Elec Eng.

Du G.,Kaifeng Power Supply Company | Liu X.,Kaifeng Power Supply Company | Su G.-F.,Xinxiang Power Supply Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

Due to the large amount of branches and high grounding resistance of distribution grid, the single-phase-to-earth fault location has not been solved effectively. The single-phase-to-earth fault location technology is proposed by combining FTU and "S" signal injection method. Firstly, the zero-sequence voltage and zero-sequence current are measured by using line FTU so that the fault area is located. Then the "S" signal is injected, and the signal can be measured by electromagnetic induction theory so as to find the exact location of grounding fault. To avoid the influence of distributed capacitance to "S" injection signal, the calculation method of length of FTU isolation area is intensively studied. Moreover, the on-line location is possible by using this method. The correctness and feasibility of this technology have been fully proved by site experiments.

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