Coherent and tunable radiation with power enhancement from surface plasmon polaritons

Surface plasmon polaritons excited by an electron beam can be transformed into coherent and tunable light radiation waves with power enhancement in the simple structure of a metal film with a dielectric medium loading. In this paper, the process of the radiation transformation of this radiation, and the dependencies of the radiation characteristics on the parameters of the structure and the electron beam are studied in detail. The radiation power enhancement is greatly influenced by the beam energy and the film thickness in the infrared to ultraviolet frequency region. Up to 122 times radiation power enhancement and 6.5% radiation frequency tuning band can be obtained by optimizing the beam energy and the parameters of the film.

Analysis of GPS P(Y) signal power enhancement based on the observations with a semi-codeless receiver

The Global Position System(GPS)satellites of Block IIR-M and later versions can turn on the signal power enhancement if needed.In recent years,this power enhancement has been triggered several times when the U.S force was involved in local conflicts,which was observed by the monitoring receivers at International GNSS Service(IGS)/international GNSS Monitoring and Assessment System(iGMAS)stations or the high-gain antennas at monitoring ground stations.The specific power enhancement magnitudes with these two observation methods are different.The observations of L1/L2 P(Y)power with a high-gain antenna are accurate,while the observations at IGS/iGMAS stations contain biases.This paper analyses the reasons for the observation biases with monitoring receivers at IGS/iGMAS stations and proposes a method verifying the accurate relation between the observed carrier-to-noise ratio(C/N_(0))data and the real power enhancement magnitudes.When the power enhancement event happens,the observed L1/L2 P(Y)C/N_(0) data at IGS/iGMAS stations can be corrected using the model proposed in this paper.In the analysis,this paper concludes that the power of L1P(Y)increases by about 4.3–5.3 dB and the power of L2P(Y)by about 4.6–5.2 dB in power enhancement events,which matches the designed capability of GPS satellites as well.The results are also verified by the data of high-gain antennas.

Power enhancement of pontoon-type wave energy convertor via hydroelastic response and variable power take-off system

Wave energy has gained its popularity in recent decades due to the vast amount of untapped wave energy resources.There are numerous types of wave energy convertor(WEC)being proposed and to be economically viable,various means to enhance the power generation from WECs have been studied and investigated.In this paper,a novel pontoon-type WEC,which is formed by multiple plate-like modules connected by hinges,are considered.The power enhancement of this pontoon-type WEC is achieved by allowing certain level of structural deformation and by utilizing a series of optimal variable power take-off(PTO)system.The wave energy is converted into useful electricity by attaching the PTO systems on the hinge connectors such that the mechanical movements of the hinges could produce electricity.In this paper,various structural rigidity of the interconnected modules are considered by changing the material Young’s modulus in order to investigate its impact on the power enhancement.In addition,the genetic algorithm optimization scheme is utilized to seek for the optimal PTO damping in the variable PTO system.It is observed that under certain condition,the flexible pontoon-type WEC with lesser connection joints is more effective in generating energy as compared to its rigid counterpart with higher connection joints.It is also found that the variable PTO system is able to generate greater energy as compared to the PTO system with constant/uniform PTO damping.

Fundamental Research on Enhancing Operation Reliability for Large-Scale Interconnected Power Grids——An interview with Zhou Xiaoxin, chief scientist of "973 Program"

At the end of last year, the editors from Power and Electrical Engineers interviewed Zhou Xiaoxin on "Fundamental Research on Enhancing Operation Reliability for Large-Scale Interconnected Power Grids", a project of "973 Program". Mr. Zhou, the chief engineer of China Electric Power Research Institute(CEPRI) and an academician of Chinese Academy of Sciences, is the chief scientist in charge of this research project.

Advancement in Science and Technology Enhanced the Growth of China's Electric Power Industry

Within the seven years’ period from 1987 to 1994. the total installed capacity of China’s electric power industry doubled from 100 GW to 200 GW. This high rate of growth has imposed new and more stringent requirements on all the branches in the

An Intelligent Intrusion Detection System in Smart Grid Using PRNN Classifier

Typically,smart grid systems enhance the ability of conventional power system networks as it is vulnerable to several kinds of attacks.These vulnerabil-ities might cause the attackers or intruders to collapse the entire network system thus breaching the confidentiality and integrity of smart grid systems.Thus,for this purpose,Intrusion detection system(IDS)plays a pivotal part in offering a reliable and secured range of services in the smart grid framework.Several exist-ing approaches are there to detect the intrusions in smart grid framework,however they are utilizing an old dataset to detect anomaly thus resulting in reduced rate of detection accuracy in real-time and huge data sources.So as to overcome these limitations,the proposed technique is presented which employs both real-time raw data from the smart grid network and KDD99 dataset thus detecting anoma-lies in the smart grid network.In the grid side data acquisition,the power trans-mitted to the grid is checked and enhanced in terms of power quality by eradicating distortion in transmission lines.In this approach,power quality in the smart grid network is enhanced by rectifying the fault using a FACT device termed UPQC(Unified Power Quality Controller)and thereby storing the data in cloud storage.The data from smart grid cloud storage and KDD99 are pre-pro-cessed and are optimized using Improved Aquila Swarm Optimization(IASO)to extract optimal features.The probabilistic Recurrent Neural Network(PRNN)classifier is then employed for the prediction and classification of intrusions.At last,the performance is estimated and the outcomes are projected in terms of grid voltage,grid current,Total Harmonic Distortion(THD),voltage sag/swell,accu-racy,precision,recall,F-score,false acceptance rate(FAR),and detection rate of the classifier.The analysis is compared with existing techniques to validate the proposed model efficiency.

Power quality enhancement and engineering application with high permeability distributed photovoltaic access to low-voltage distribution networks in Australia

Considering power quality problems such as overvoltage and three-phase unbalance caused by high permeability distributed photovoltaic access in low-voltage distribution networks,this paper proposes a comprehensive control scheme using a static var.generator(SVG),electric energy storage(EES),a phase switching device(PSD)and an intelligent terminal controller.The control strategies of transformer overload,bus over/under voltage,anticountercurrent,storage battery state of charge(SOC)maintenance,and three-phase unbalance are studied.The engineering application in the Greenvale low-voltage distribution networks in Australia with high permeability distributed photovoltaics is discussed.The results show that the intelligent terminal controller is able to improve the power quality of low-voltage distribution networks through coordination with EES,SVG and PSD.

Enhancement of output power density in a modified polytetrafluoroethylene surface using a sequential O_(2)/Ar plasma etching for triboelectric nanogenerator applications

In this work,the surface modification using a two-steps plasma etching has been developed for enhancing energy conversion performance in polytetrafluoroethylene(PTFE)triboelectric nanogenerator(TENG).Enhancing surface area by a powerful O_(2) and Ar bipolar pulse plasma etching without the use of CF_(4) gas has been demonstrated for the first time.TENG with modified surface PTFE using a sequential two-step O_(2)/Ar plasma has a superior power density of 9.9 W·m^(-2),which is almost thirty times higher than that of a pristine PTFE TENG.The synergistic combination of high surface area and charge trapping sites due to chemical bond defects achieved from the use of a sequential O_(2)/Ar plasma gives rise to the intensified triboelectric charge density and the enhancement of power output of PTFE-based TENG.The effects of plasma species and plasma etching sequence on surface morphologies and surface chemical species were investigated by a field emission scanning electron microscopy(FESEM),atomic force microscopy(AFM),and X-ray photoelectron spectroscopy(XPS).The correlation of surface morphology,chemical structure,and TENG performance was elucidated.In addition,the applications of mechanical energy harvesting for lighting,charging capacitors,keyboard sensing and operating a portable calculator were demonstrated.

Decomposed input-output stability analysis and enhancement of integrated power systems

The integrated power system(IPS) is a foundation of all-electrical ships and vessels. The stability of IPS becomes a prerequisite of complicated cruise tasks. Thus, advanced stability analysis and regulation methods for IPS are of great importance. In this paper, a novel method is proposed for analyzing and enhancing transient stability of IPS, which is regarded as a cyber-physical system comprising of subsystems and connections. Criterions for determining input-output stability of such a system are firstly derived. Then, the stability analysis of IPS can be performed in the following two steps: 1) evaluating local input-output stability features of each subsystem independently through simulations. 2) Checking stability criterions with system topology and subsystem stability features. Moreover, synthetic approaches are proposed for stabilization and stability enhancement of IPS. To avoid system in-stability after major failures or topology changes, the optimal emergency control is performed to reconfigure subsystems. The other optimal regulation is used to strengthen system stability by adjusting subsystems' control parameters during normal operation conditions. Case studies on a typical IPS validate the proposed stability analysis and enhancement approach.

An Efficient Approach for Segmentation, Feature Extraction and Classification of Audio Signals

Due to the presence of non-stationarities and discontinuities in the audio signal, segmentation and classification of audio signal is a really challenging task. Automatic music classification and annotation is still considered as a challenging task due to the difficulty of extracting and selecting the optimal audio features. Hence, this paper proposes an efficient approach for segmentation, feature extraction and classification of audio signals. Enhanced Mel Frequency Cepstral Coefficient (EMFCC)-Enhanced Power Normalized Cepstral Coefficients (EPNCC) based feature extraction is applied for the extraction of features from the audio signal. Then, multi-level classification is done to classify the audio signal as a musical or non-musical signal. The proposed approach achieves better performance in terms of precision, Normalized Mutual Information (NMI), F-score and entropy. The PNN classifier shows high False Rejection Rate (FRR), False Acceptance Rate (FAR), Genuine Acceptance rate (GAR), sensitivity, specificity and accuracy with respect to the number of classes.

Performance enhancement of partially shaded solar PV array using novel shade dispersion technique

Solar photo voltaic array （SPVA） generates a smaller amount of power than the standard rating of the panel due to the partial shading effect. Since the modules of the arrays receive different solar irradiations, the P-V characteristics ofphotovoltaic （PV） arrays contain multiple peaks or local peaks. This paper presents an innovative method （magic square） in order to increase the generated power by configuring the modules of a shaded photo- voltaic array. In this approach, the physical location of the modules in the total cross tied （TCT） connected in the solar PV array is rearranged based on the magic square arrangement pattern. This connection is done without altering any electrical configurations of the modules in the PV array. This method can distribute the shading effect over the entire PV array, without concentrating on any row of modules and can achieve global peaks. For different types of shading patterns, the output power of the solar PV array with the proposed magic square configuration is compared with the traditional configurations and the performance is calculated. This paper presents a new reconfiguration technique for solar PV arrays, which increases the PV power under different shading conditions. The proposed technique facilitates the distribution of the effect of shading over the entire array, thereby, reducing the mismatch losses caused by partial shading. The theoretical calculations are tested through simulations in Matlab/ Simulink to validate the results. A comparison of power loss for different types of topologies under different types of shading patterns for a 4 × 4 array is also explained.

EV charging station with cascaded low-pass filtering scheme-based control of unified power quality conditioner

This paper proposes a cascaded low-pass filter(CLPF)scheme for the control of a unified power quality conditioner(UPQC)installed for enhancing the power quality of an electric vehicle(EV)charging station.With the incorporation of UPQC,the EV charging station draws sinusoidal currents at unity power factor and the supply voltage is maintained at the nominal value at the charger input.In the CLPF scheme,theα-βcomponents of the load current are individually processed through a cascade connection of two LPFs to determine the corresponding fundamental orthogonal components.Based on thus determined components,the instantaneous and peak value and phase angle of the fundamental positive sequence component(FPSC)of the load current are computed.Similarly,the corresponding quantities related to the load and supply voltages are also computed with the CLPF scheme.With the computations related to the load current and supply voltage,the unit voltage templates(UVTs),power factor and fundamental active component(FAC)of the load current are calculated.For the control of shunt compensation,reference currents are generated based on the FAC of the load current and UVTs.Alternately,the control of series compensation is employed with the help of UVTs and peak amplitude of the FPSC of the load voltage.The performance of CLPF scheme-based extraction is compared with that of the earlier reported schemes through simulation and experimental studies.The performance comparison reveals a faster dynamic and more accurate steady-state response with the proposed scheme.The performance analysis of the proposed CLPF scheme-based control of a UPQC deployed at the EV charging station for different operating conditions demonstrates station operation with requisite reactive power compensation and mitigation of voltage sag/swell,and prevention of propagation of harmonic and unbalanced currents into the grid.This results in increased reliability of charger operation,energy savings and increased efficiency of the distribution network.

The abstract of doctoral dissertation‘Some research on hypothesis testing and nonparametric variable screening problems for high dimensional data’

In this thesis,we construct test statistic for association test and independence test in high dimension,respectively,and study the corresponding theoretical properties under some regularity conditions.Meanwhile,we propose a nonparametric variable screening procedure for sparse additive model with multivariate response in untra-high dimension and established some screening properties.

Facile and robust strategy to antireflective photo-curing coating through self-wrinkling

We reported a facile and bio-inspired strategy for obtaining antireflective （AR） coating through polymerization-induced self-wrinkling. Upon irradiation of light, the complex wrinkle micro-patterns with different morphologies were generated spontaneously on the surface of coating during photo-cross- linking, which enables the photo-curing coating can decrease reflection. The resulting photo-curing coating exhibits a high transmittance over 90% and low reflection below 5% ～ 8%, with an efficiency anti- reflection of 4% ～ 7%; compared to the flat blank coating. The successful application of these AR coatings with wrinkles pattern to encapsulate the thin film solar cells results in appreciable photovoltaic performance improvement of more than 4% ～ 8%, which benefits from the decrease of the light reflection and increase of optical paths in the photoactive layer by the introduction of wrinkling pattern. Furthermore, the efficiency improvements of the solar cells are more obvious, with a remarkable increase of 8.5%, at oblique light incident angle than that with vertical light incident angle