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40 results on '"Zha Zhipeng"'

1. Bulk plasmon polariton in hyperbolic metamaterials excited by multilayer nanoparticles for surface-enhanced Raman scattering (SERS) sensing

Author

Liu Runcheng, Zha Zhipeng, Shafi Muhammad, Li Can, Yang Wen, Xu Shicai, Liu Mei, and Jiang Shouzhen

Subjects
bulk plasmon polariton, hyperbolic metamaterials, surface-enhanced raman scattering, surface plasmon polariton, Physics, QC1-999
Abstract

The capability to support large wave vector bulk plasmon polariton (BPP) waves enables the application of hyperbolic metamaterials (HMMs) in sensing. However, there is a challenge arising from the excitation of BPP, and the highly confined polarization waves are unable to meet the requirements of practical application. In this study, an HMM/bilayer silver nanoparticles (Ag NPs) platform is proposed that allows the excitation and utilization of BPP for use as a surface-enhanced Raman scattering (SERS) substrate. According to the research results, the bilayer Ag NPs provide stronger plasmonic property and act as a light-matter coupler, so as to generate a large wave vector of scattered light and excite the BPP within the HMM. Besides, Ag NPs provide the nano antenna structure, and decouple the BPP into localized surface plasmon (LSP) that can be used directly to excite the electric fields. In addition, HMM produces a modulating effect on the plasmon resonance peak, which makes it possible to overlap the spectrum of resonance peak with excitation wavelengths, thus leading to a strong absorption peak at the incident laser wavelength region. Experimentally, the platform was applied to achieve SERS detection for adenosine molecules with a concentration of 10−6 M. It is believed that this plasmonic platform has a potential of application in surface-enhanced spectroscopy.

Published
2021
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2. Research on DC component decay time constant of 1000 kV AC filter circuit breakers in UHV converter station

Author

Li Zhenqiang, Fan Mian, He Ying, and Zha Zhipeng

Subjects
short-circuit currents, fault currents, EMTP, earthing, circuit breakers, HVDC power convertors, substations, power filters, time 75 ms, voltage 500 kV, voltage 1000.0 kV, time 90.0 ms, current 63.0 kA, filter single-phase to earth fault current, electromagnetic transient program, AC filter subbank, breaker tests, UHV DC projects, time constant calculated, short-circuit current, UHV AC filter circuit breakers, test DC component decay time, UHV converter station, Engineering (General). Civil engineering (General), TA1-2040
Abstract

In hierarchically connected UHV DC projects, the 1000 kV AC filter sub-bank in converter station is provided with two 500 kV circuit breakers. To determine the test DC component decay time constant when breakers break short-circuit current, relevant DC project was modelled in electromagnetic transient program (EMTP) for calculations. It is pointed out that for UHV AC filter circuit breakers, the decay time constant of DC component of short-circuit current should be determined solely based on the single-phase to earth fault current. Calculations and analyses were made of the AC and DC components and the DC component decay time constant of filter single-phase to earth fault current, and the time constant calculated was converted to the test value of breakers with rated short-circuit breaking current of 63 kA. According to the research results, a time constant of 75 or 90 ms is recommended for the two 500 kV circuit breakers, and it is lower than 120 ms as required by the relevant standards, providing technical support for future breaker tests.

Published
2019
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9. Ultrafast Response/Recovery Acetone Gas UV Absorption Sensor Based on Ag/PEEK Hollow Fiber

Author

Zha, Zhipeng, Liu, Sheng, Hou, Guangning, Zhu, Yizhen, Yu, Shuoying, Zhang, Qingtian, Jing, Chengbin, and Chu, Junhao

Abstract

The achievement of ultrafast and precise detection of acetone is of great significance for industrial production and public safety. In this study, we designed an acetone gas sensing system based on a silver-coated polyether ether ketone (Ag/PEEK) plastic hollow fiber, which served as both a gas cell and the UV light transmission waveguide. Ultrafast response/recovery detection of acetone gas was achieved by the 274-nm absorption of acetone molecules in the hollow fiber. The effects of fiber inside diameter and length on sensing performance parameters, such as response/recovery times and sensitivity were investigated. Both an increase in fiber inside diameter and length result in extended response/recovery time, while the enhancement in sensitivity is primarily attributed to the fiber length increase. The absorption of the acetone gas sample exhibited an excellent linear relationship with its concentration ranging from 0.31 to 18.72 mg/L, with a correlation coefficient of ${R} ^{{2}} \gt 0.996$ . The hollow fiber sensor, with optimized structural dimensions (2 mm inside diameter and 150-cm length), exhibited a response/recovery time of 0.9/0.85 s for acetone gas, a sensitivity of 0.05218 a.u. $\cdot $ mg $^{-{1}} \cdot $ L $^{-{1}}$ , and an LOD was 0.078 mg/L. When bending at radii of 25 cm for 180° and 20 cm for 360°, it could detect acetone gas with concentrations of 0.62–18.72 and 1.87–18.72 mg/L, respectively. This sensor has practical potential for real-time online detection of hazardous gases in industrial production, environmental protection, and human health, owing to its low fabrication cost, ductile gas cell, and high sensing performances.

Published
2024
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27. Research on DC component decay time constant of 1000 kV AC filter circuit breakers in UHV converter station

Author

He Ying, Fan Mian, Li Zhenqiang, and Zha Zhipeng

Subjects
earthing, Materials science, fault currents, time constant calculated, Energy Engineering and Power Technology, HVDC power convertors, time 90.0 ms, UHV AC filter circuit breakers, test DC component decay time, time 75 ms, UHV converter station, Electronic filter, EMTP, substations, current 63.0 kA, business.industry, power filters, General Engineering, Electrical engineering, voltage 1000.0 kV, electromagnetic transient program, short-circuit current, short-circuit currents, AC filter subbank, breaker tests, Decay time, voltage 500 kV, lcsh:TA1-2040, UHV DC projects, circuit breakers, filter single-phase to earth fault current, lcsh:Engineering (General). Civil engineering (General), business, Constant (mathematics), Software, DC bias
Abstract

In hierarchically connected UHV DC projects, the 1000 kV AC filter sub-bank in converter station is provided with two 500 kV circuit breakers. To determine the test DC component decay time constant when breakers break short-circuit current, relevant DC project was modelled in electromagnetic transient program (EMTP) for calculations. It is pointed out that for UHV AC filter circuit breakers, the decay time constant of DC component of short-circuit current should be determined solely based on the single-phase to earth fault current. Calculations and analyses were made of the AC and DC components and the DC component decay time constant of filter single-phase to earth fault current, and the time constant calculated was converted to the test value of breakers with rated short-circuit breaking current of 63 kA. According to the research results, a time constant of 75 or 90 ms is recommended for the two 500 kV circuit breakers, and it is lower than 120 ms as required by the relevant standards, providing technical support for future breaker tests.

Published
2018

35. Delayed Current Zero Crossing Characteristics for Circuit Breaker Interrupting Short-Circuit Current Following Permanent Single-phase Ground Fault on Short 1000kV AC Lines

Author

Ying Lou, Zha Zhipeng, Zhenqiang Li, and Wan Lei

Subjects
Overburden, Control theory, Computer science, Current (fluid), Fault (power engineering), Zero crossing, Tower, Short circuit, Circuit breaker, Electronic circuit
Abstract

For double or multiple circuits of 1000kV lines on the same tower, where a permanent single-phase ground fault occurs on one circuit, delayed current zero crossing may take place during single-phase reclosing of circuit breaker. This may overburden and even damage the breaker. This paper uses the ATP-EMTP program to simulate various operating conditions of a 1000kV system with varying grid configuration, line length, number of circuits, time of single-phase reclosing and location of fault, and proposes the probability of occurrence of delayed current zero crossing accordingly.

Published
2019

36. Research on DC Component Decay Time Constant of 1000 kV AC Filter Circuit Breakers in UHV Converter Station

Author

Zhenqiang Li, Minghao Fan, Zha Zhipeng, and Peihong Zhou

Subjects
Materials science, Emtp, business.industry, 020209 energy, Electrical engineering, Time constant, 02 engineering and technology, Filter (video), 0202 electrical engineering, electronic engineering, information engineering, Transient (oscillation), business, Constant (mathematics), Electronic filter, Circuit breaker, DC bias
Abstract

In hierarchically connected UHV DC projects, the 1000 kV AC filter sub-bank in converter station is provided with two 500 kV circuit breakers. To determine the test DC component decay time constant when breakers break short-circuit current, relevant DC project was modelled in electromagnetic transient program (EMTP) for calculations. It is pointed out that for UHV AC filter circuit breakers, the decay time constant of DC component of short-circuit current should be determined solely based on the single-phase to earth fault current. Calculations and analyses were made of the AC and DC components and the DC component decay time constant of filter single-phase to earth fault current, and the time constant calculated was converted to the test value of breakers with rated short-circuit breaking current of 63 kA. According to the research results, a time constant of 75 ms or 90 ms is recommended for the two 500 kV circuit breakers, and it is lower than 120 ms as required by the relevant standards, providing technical support for future breaker tests.

Published
2018

39. Electromagnetic Transient Analysis of 750kV Four-circuit Transmission Line on the Same Tower

Author

Ying Lou, Zha Zhipeng, He Huiwen, and Li Zhenqiang

Subjects
Physics, business.industry, Transmission line, Structural engineering, business, Transient analysis, Tower
Abstract

The ATP-EMTP program is used to calculate the power frequency overvoltage, open-phase power frequency resonant overvoltage, induced voltage and current, secondary arc current and recovery voltage, and switching overvoltage of 750kV four-circuit transmission line on the same tower. The study reveals that the configuration of four circuits on the same tower has little influence on the power frequency and switching overvoltage, but greatly influences the secondary arc current and recovery voltage, and induced voltage and current. Therefore, measures like installing high-voltage shunt reactor and neutral grounding reactor and line transposition are required. Also, the induced voltage and current ratings of earthing switch are proposed.

Published
2019

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