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Hauppauge, NY, United States

Zhu Y.-F.,Jiangxi Normal University | Chen M.-Y.,Jiangsu University | Wang H.,Communication Power Corporation
IEEE Transactions on Terahertz Science and Technology | Year: 2015

We present a design and investigation of a low-loss terahertz fiber consisting of crossed rectangular shaped dielectric strips and a supporting outer cladding. The core-guided mode can be effectively confined in the fiber core with a large portion of mode power distributed in air holes adjacent to the solid material, which results in a low absorption loss property of the fiber. Low dispersion transmission can be obtained due to the thinner dielectric strips. In addition, a high birefringence on a level of 10 -2 over a wide frequency range can be obtained by simply adopting crossed dielectric strips with different thicknesses. © 2011-2012 IEEE.

Chen G.,China Southern Power Grid Co. | Duan X.,Chongqing University | Zhang J.,Chongqing Electrical Power Corporation | He Q.,Communication Power Corporation | Wu X.,China Southern Power Grid Co.
Dianwang Jishu/Power System Technology | Year: 2010

To improve real-time monitoring level of low frequency oscillation in power grids, on the basis of analyzing low frequency identification methods based on auto-regressive moving-average (ARMA) and wide area measured noise like signals, an order determination approach for ARMA model based on singular value decomposition is given; then it is proposed to identify the dominant mode of low frequency oscillation by ARMA spectral estimation after the parameters of ARMA model are identified; finally, combining with engineering practice, a wide area measurement system (WAMS) based on-line identification framework for low frequency oscillation modes is put forward, which mainly composes of data preprocessing, parameter tracking of low frequency oscillation mode based on ARMA model and sliding window, and identification strategy of dynamic response signals under large disturbance, etc. By means of time-domain simulation of testing system and the analysis on noise like data measured in China Southern Power Grid by WAMS, it is indicated that the proposed approach can identify the dominant mode of low frequency oscillation accurately, especially, higher parameter identification accuracy can be attained for weak-damping mode, so the proposed approach is practicable.

Chen G.,Chongqing University | Ma A.,Chongqing University | Zhang J.,Chongqing Electrical Power Corporation | Tang Y.,Chongqing University | He G.,Communication Power Corporation
Dianwang Jishu/Power System Technology | Year: 2010

Voltage and reactive power control (VQC) in substations is an important component of automatic voltage control (AVC). In view of the defects that traditional VQC strategies are not adapted to AVC and their control effects are unsatisfied, in this paper a new VQC strategy for substation is proposed. According to this strategy and based on desired voltage value of AVC, adjusting times of on-load tap changer (OLTC) and switching times of capacitor banks, a multi-objective decision-making model is constructed. For the selectable schemes to solve the proposed model an objective decision matrix is built and through non-dimension treatment the objective decision matrix is changed into relative superior attribute degree matrix of all objectives. To overcome the shortcoming of single weight determination and make the determination of weight more effective and reasonable, the improved analytical hierarchy process (AHP), i.e., the subjective weight determining, and dispersion maximization, i.e., the objective weight determining, are integratively utilized to determine the weight the weights of indices. Finally, the optimal control strategy is solved by multi-objective decisionmaking based linear weighted sum. The feasibility and superiority of the proposed control strategy are verified by calculation example.

Zhu Y.,Jiangsu University | Chen M.,Jiangsu University | Wang H.,Communication Power Corporation | Zhang Y.,Jiangsu University | Yang J.,Jiangsu University
Plasma Science and Technology | Year: 2014

A novel design is proposed for highly sensitive surface-plasmon-resonance sensors. The sensor is based on a microstructured optical fiber with two layers of annular-shaped holes. A gold layer is deposited on the inner surface of the second hole-layer, in which the holes have several micrometers thickness in size, facilitating analyte infiltration and metal layer deposition. In the first layer of holes, the sector-ring-shaped arms, used as supporting strips, are utilized to tune the resonance depth of the sensor. Numerical results indicate that the sensor operation wavelength can be tuned across the C+L-band. The spectral sensitivity of 1.0·104nm ·RIU-1order of magnitude and a detection limit of 1.0 · 10-4RIU order are demonstrated over a wide range of analyte refractive index from 1.320 to 1.335.

Zhu Y.-F.,Jiangsu University | Chen M.-Y.,Jiangsu University | Wang H.,Communication Power Corporation | Yao H.-B.,Jiangsu University | And 2 more authors.
IEEE Photonics Journal | Year: 2013

We propose the design of a low-loss suspended core terahertz fiber with rectangular-shaped dielectric strips in the fiber cross section. The finite element method is used to analyze the characteristics of the suspended core terahertz fiber. Terahertz wave in a frequency range from 0.74 ∼ 0.95 THz is efficiently confined in the suspended core region with a total loss lower than 0.086 dB/cm (∼ 0.02cm-1). Meanwhile, any contact on the surface of this fiber will not disturb the field and induce additional losses. A 3.36-cm-long terahertz polarization splitter derived from this fiber with a transmission loss less than 0.89 dB, is also numerically demonstrated. A bandwidth of 0.032 THz at the center frequency of 1 THz with an extinction ratio better than-20 dB is obtained. © 2009-2012 IEEE.

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