- 标题
- 摘要
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- 实验方案
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Thermal design and analysis of the high resolution MWIR/LWIR aerial camera
摘要： The thermal control technology of high resolution MWIR/LWIR aerial camera is studied. Thermal design and thermal analysis of the camera are completed according to thermal control indexes of infrared aerial camera. Firstly the architecture of the aerial camera and the external working environment are introduced, the camera heat exchange model is established, and the boundary conditions of radiation, conduction, convection and aerodynamic heat are analyzed, and then the thermal design of the camera is described in detail. Finally the thermal analysis of aerial camera is done, and a heat balance test has been done for the camera. The results show that: In the speci?ed environment, after two hours work the temperature range of optical system is 18.5 ℃ to 22.2 ℃, the temperature range of lens set is 19.1 ℃ to 20.3 ℃, the temperature range of detector module is 19.7 ℃ to 31.9 ℃, meet the thermal control indexes, at the same time, under extreme operating conditions, the thermal control system can meet the start-up requirements, the thermal design is feasible and reasonable. This research method and technical route have the guidance and reference signi?cance for the thermal control design of other infrared aerial cameras.
关键词： Infrared aerial camera,Thermal control system,Thermal design,Thermal analysis
更新于2025-09-04 15:30:14
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Optimization and modeling of UV-TiO <sub/>2</sub> mediated photocatalytic degradation of golden yellow dye through response surface methodology
摘要： In this article, heterogeneous photocatalysis of golden yellow (GY) dye by Evonik p25 titanium dioxide (PTD) and UV radiations was optimized by using central composite design of response surface methodology. The GY dye photocatalysis was expressed as the function of amount of PTD loading (X1), GY dye initial concentration (X2), and UV irradiance intensity (X3). The optimization of degradation conditions was done by measuring two different responses, that is, color removal (Y1) and chemical oxygen demand removal (Y2). The effect of X1, X2, and X3 were studied in the range 0.5–1.5 g/L, 15–35 W/m2, and 10–30 mg/L, respectively. The quadratic model was suggested for Y1 and Y2. The numerical optimization of results was done via Design Expert software. The predictive results obtained were verified by performing actual experiments. The photodegradation kinetics, total organic carbon disappearance, effect of inorganic salts, and H2O2 concentration on GY dye photodegradation were also studied.
关键词： Titanium dioxide,Heterogeneous photocatalysis,Central composite design,Optimization,Golden yellow dye,Response surface methodology
更新于2025-09-04 15:30:14
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Load-Independent Wireless Power Transfer System for Multiple Loads Over a Long Distance
摘要： In this paper, a novel long-distance wireless power transfer (WPT) system using repeater coils is proposed to provide power supplies for the driver circuits in high voltage applications such as flexible alternative current transmission systems (FACTS). Different from most of the existing wireless repeater systems where the load is only connected to the last coil and the repeater coils function solely as power relays, in the proposed system, multiple loads are powered by the repeaters. The repeater coils transfer power not only to the subsequent coils but also to the loads connected to them. Dual coil design is proposed for the repeaters with which load-independent characteristics are obtained with a suitable design of coupling coefficients. As a result, the load power can be easily adjusted without affecting each other. Load current characteristics and system efficiency have been analyzed in detail. The power transfer capability of the proposed system is illustrated for different coil quality factors and coupling coefficients. An experimental setup with 10 loads has been built to validate the effectiveness of the proposed long-distance WPT system. The maximum reachable system efficiency is about 84%.
关键词： dual coil design,Wireless power transfer (WPT),constant load characteristics,current independent,long distance
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Atlanta, GA, USA (2018.10.31-2018.11.2)] 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Thermal Characterization and Design for a High Density GaN-Based Power Stage
摘要： This paper proposes a methodology for extracting the thermal equivalent circuit of a high density GaN-based power stage, using a 48 V to 12 V GaN-based synchronous buck converter as the test platform. The test setup calculates the junction temperatures by measuring Rds,on for both FETs in the half bridge, while current sources produce power losses in each device and the output filter inductor. Independent control of the two gate voltages allows for either symmetric or asymmetric distribution of power loss between the two FETs, and comparison of these results are used to calculate the coupled and uncoupled thermal resistances between them. The thermal interaction with the filter inductor is similarly modeled. The baseline thermal design with a bare PCB and no heatsink was characterized, as well as a proposed thermal solution consisting of a heatsink, gap pad, gap filler, and a plastic shim. Each configuration was tested with three air flow conditions, and the resulting thermal model was used to estimate the maximum current capability without exceeding 100 °C on either FET. The proposed thermal solution improves the maximum current-handling capability by over 60% compared with the baseline design.
关键词： thermal characterization,eGaN FET,thermal design,HEMT,HFET,heatsink,junction temperature,GaN
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Passive Filter Design to Mitigate Dead-Time Effects in Three-Level T-Type NPC Transformerless PV Inverters Modulated with Zero CMV PWM
摘要： Common-mode voltage (CMV) can cause common-mode (CM) current in transformerless PV inverters. In practice, large CM choke is usually required to suppress the CM current. Alternatively, zero common-mode voltage (ZCMV) modulation can be applied to eliminate the CMV. But in practical applications, CMV spikes are inevitable due to the dead-time effect. Such dead-time effect can be mitigated by special PWM sequence design, however, at the expense of increasing switching losses. In this paper, our study addresses this issue by using the DC neutral-point connected LCL (NC-LCL) filter. As the differential-mode (DM) output quality is undermined with ZCMV PWM, the LCL filter parameters must be carefully designed, where both CM and DM filters need to be considered. In addition, filter design for conventional phase disposition (PD) modulation is also included as a comparison. Both simulation results and experimental results are provided for verification.
关键词： Photovoltaic (PV) solar inverter,LCL filter design,Phase disposition modulation,T-type 3L-NPC (PD) inverter,Zero CMV modulation
更新于2025-09-04 15:30:14
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A Time-Domain Computing Accelerated Image Recognition Processor With Efficient Time Encoding and Non-Linear Logic Operation
摘要： Time-domain computing (TC) has drawn significant attention recently due to its highly efficient computation for applications such as image processing and neural network computing. This paper presents novel time-domain circuit techniques, including: 1) double-encoding strategy; 2) bit-scalable design that accelerates the performance compared with previous linear coding; and 3) shared time generator (TG) with variation-aware design technique which significantly improves the error tolerance of TC. A feature-extraction and vector-quantization processor accelerated by TC has been developed for real-time image recognition. A 55-nm prototype chip shows 72-fps/core (at 1.33 GHz) operation with up to 42% area and power saving from TC compared to the conventional digital implementation.
关键词： Bit-scalable design,winner-take-all (WTA),double-encoding scheme,time-domain computing (TC),image processing,median filter (MF)
更新于2025-09-04 15:30:14
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Multivariate Spatio-temporal Solar Generation Forecasting: A Unified Approach to Deal With Communication Failure and Invisible Sites
摘要： Short-term prediction of multivariate dynamical processes evolving over time when data are partially observable is a challenging task. The power from solar resources has reached grid parity and must be predicted based on real-time observations available up to the current time step to ensure efficient power systems operation. However, solar data in the form of a time series generated by a network of sensors are not always available. Invisible solar sites and communication failure are two causes that leave the energy management data acquisition system with an incomplete solar time series, thus leading to inaccurate forecasts. This paper addresses the impact of partially observable measurements on short-term solar power prediction. We present a low-rank tensor learning scheme to predict six-hour-ahead solar power generation. We use actual multivariate spatio-temporal National Renewable Energy Laboratory solar data in the state of Kansas presented in the form of tensors along with a photovoltaic power conversion model. A design of experiments experimental framework has been proposed to evaluate single and joint effects of spatio-temporal partially observable sites and the regulating parameters on forecasting accuracy. Numerical results show the capability of the framework to uncover detailed insight into the forecasting model behavior.
关键词： tensor,design of experiments (DOE),invisible sites,missing data,spatio-temporal prediction,Communication failure
更新于2025-09-04 15:30:14
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Sensor Array Design Through Submodular Optimization
摘要： We consider the problem of far-field sensing by means of a sensor array. Traditional array geometry design techniques are agnostic to prior information about the far-field scene. However, in many applications such priors are available and may be utilized to design more efficient array topologies. We formulate the problem of array geometry design with scene prior as one of finding a sampling configuration that enables efficient inference, which turns out to be a combinatorial optimization problem. While generic combinatorial optimization problems are NP-hard and resist efficient solvers, we show how for array design problems the theory of submodular optimization may be utilized to obtain efficient algorithms that are guaranteed to achieve solutions within a constant approximation factor from the optimum. We leverage the connection between array design problems and submodular optimization and port several results of interest. We demonstrate efficient methods for designing arrays with constraints on the sensing aperture, as well as arrays respecting combinatorial placement constraints. This novel connection between array design and submodularity suggests the possibility for utilizing other insights and techniques from the growing body of literature on submodular optimization in the field of array design.
关键词： Array design,submodular optimization,far field sensing
更新于2025-09-04 15:30:14
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Development of the Full Package of Gyrotron Simulation Code
摘要： A complete code-package for gyrotron simulation to analyze its performance is under development in UNIST, Korea. We first time report the present status of the code-package named as UNIST Gyrotron Design Tool (UGDT). It can perform design simulations for gyrotron’s interaction cavity, RF window, and the essential mode calculations including the study of mode competition. We will discuss about its salient features, theory, numerical implementation, and its calculation result for 95 GHz UNIST Gyrotron. Moreover, we will validate its capability to perform the mode competition calculation for fundamental and second harmonic modes.
关键词： Harmonic operation,Mode competition,Gyrotron design code,Gyrotron
更新于2025-09-04 15:30:14