A5049493575- Solar Thermal and Photovoltaic Systems
- Photovoltaic System Optimization Techniques
- solar cell performance optimization
- Solar Radiation and Photovoltaics
- Electric Motor Design and Analysis
- Advanced DC-DC Converters
- Multilevel Inverters and Converters
- Sensorless Control of Electric Motors
- Building Energy and Comfort Optimization
- High-Temperature Coating Behaviors
- Aluminum Alloys Composites Properties
- Heat Transfer and Optimization
- Silicon Carbide Semiconductor Technologies
- Erosion and Abrasive Machining
- Silicon and Solar Cell Technologies
- Heat Transfer Mechanisms
- Calibration and Measurement Techniques
- Machine Fault Diagnosis Techniques
- Non-Destructive Testing Techniques
- Solar Energy Systems and Technologies
- Thermal Radiation and Cooling Technologies
- Wind Turbine Control Systems
- Spacecraft and Cryogenic Technologies
- Electric and Hybrid Vehicle Technologies
- HVDC Systems and Fault Protection
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2022-2024
National Institute of Chemistry
2020
KTH Royal Institute of Technology
2020
Fairchild Semiconductor (United States)
2005
National Research Council Canada
1989-1990
Solar thermal absorber coatings play a key role in the efficiency of receivers for applications field Concentrated Power (CSP). The development stable spectral selective with high solar absorptance αsol and low emittance εth is often desired to reduce losses. However, quantitative indicators describing selectivity trade-off between seldom discussed literature. In this review, relevant opto-thermal figures merit are analyzed comparison reference coatings, including real ideal both black...
Solar thermal absorber coatings play an important role in the opto-thermal efficiency of receivers Concentrated Power (CSP). Two standard figures merit are solar absorptance αsol and emittance εth, derived from spectral directional hemispherical reflectance measurements at room temperature. These two allow comparing coating formulations terms performance durability. In this study, a black selective optically characterized by different laboratories to compare datasets, εth calculations. The...
The heat loss of an evacuated parabolic trough receiver solar thermal power plants ranges typically between values below 150 and 200 W/m at 350°C. Defects, such as glass breakage by wind events coating degradation, anti-reflection degradation or hydrogen accumulation in the annulus, decrease annual electricity production. This study examines effect different performance scenarios on energetic economic output a modern 150-MWel–parabolic plant with 7.5-hours molten-salt storage, located Ma'an,...
The receiver tube of the parabolic trough collectors may suffer a degradation vacuum atmosphere between glass envelope and absorber due to permeation gases, mainly hydrogen or air. This is one most common issues heat loss increase in solar fields with this type collectors. Surface Temperature Method has been used determine complete partial annulus tubes, by measuring temperature envelope. In work, influences meteorological variables source distance on measurement infrared thermography are...
The paper presents a compact power amplifier (PA) topology for reducing quiescent current and consumption under backoff operation. final stage of the PA consists two parallel transistor cells designed different output operations. By switching between cells, terminated with load impedances, through unique bias control network, improved efficiency is achieved over wide range low compared to conventional PA. A 1.95 GHz WCDMA InGaP/GaAs HBT module (PAM) has been developed validate proposed...
This paper describes a transient thermography method to measure the heat loss of parabolic trough receivers and separate their mechanisms. is complementary existing stationary techniques, which use either energy balances or glass envelope temperature measurements derive overall losses. It shown that receiver can be calculated by applying thermal excitation on absorber tube measuring both signals. Additionally, emittance selective coating vacuum quality annulus derived. The benefits limits...
The solar receiver coating opto-thermal efficiency has a significant impact on central system thermal final efficiency. development of durable high absorptance coatings with simple application process and minimal treatment can directly improve the efficiency, thus reducing levelized cost electricity. During past years, innovative for tower plants have been developed various substrates tested under isothermal load at different temperature levels. In this paper, eight commercial black...
An intercomparison of opto-thermal spectral measurements has been performed for some relevant receiver materials in concentrating solar thermal applications, from room temperature up to 800°C. Five European laboratories at temperature, while two infrared operating 800 °C. Relevant include Haynes 230 (oxidized, Pyromark 2500 and industrial black coating) silicon carbide. Two key figures merit were analyzed: i) absorptance αsol over the range [0.3 – 2.5] μm, ii) emittance εth(T), common [2-14]...
In this paper, a generalized scalable configuration of hybrid paralleled modular active neutral point clamped (PM-ANPC) converter comprising silicon (Si) and carbide (SiC) based power devices is proposed. Moreover, an improved modulation method proposed for equal current distribution between the legs, reduced switching frequency high (HF) switches, amended harmonic spectrum output voltage, decoupled control low (LF) HF switches. Hence, applying enables utilizing Si switches in LF part SiC...
This paper reports experimental results for accelerated ageing test campaigns performed on four different solar receiver coatings applied T91 and VM12 steel substrates. tubular samples are exposed at a dish facility in order to perform thermal cycles under concentrated flux. No significant optical degradation could be observed coated after 100 (50 hours 650 °C), while bare polished reference substrates oxidized during testing. Three achieved stable weighted absorptance αs above 95 %...
This paper describes a thermodynamic model library developed with the object-oriented language Modelica, which is both implemented for steady-state and transient heat transfer analyses of Parabolic Trough Receivers (PTRs) installed in Concentrated Solar Power (CSP) plants. For identification PTR loss mechanisms, this coupled to derivative-free hybrid optimization routine Matlab, combining Particle Swarm Optimization (PSO) algorithm Nelder-Mead Simplex (NMS) search space boundary constraints.
This paper describes a transient infrared thermography heat loss measurement method for parabolic trough receiversand its development under laboratory conditions. The is designed future field measurements and represents complementary approach to steady-state methods. receiver specific determined by applying thermal excitation the absorber tube measuring both glass temperature response signals with pyrometers. These are processed derive mean temperature, an amplitude ratio phase shift at air...
Photoelectrochemical water splitting is a promising pathway for solar-driven hydrogen production with low environmental footprint. The utilization of solar concentrators to supply such devices concentrated irradiation offers great potential enhance the economic viability at “sunny” site locations. In this work, we defined set functional requirements assess their suitability power devices, taking into account concentrator optical performance, device coupling efficiency, perceived system...
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Precise knowledge of particle optical properties is crucial to the advancement and success directly-irradiated receiver technologies. This work presents results a Round Robin Test (RRT) that was conducted between seven laboratories, where each participant measured absorptance emittance for set five different types. research performed within framework SolarPACES Task III group, helped establish guideline evaluating particles. The published on website in May 2022.
The parameters of equivalent electrical model Induction Machines are necessary for appropriate operation conventional drive systems. This paper proposes a novel and fast approach IMs identification at standstill condition. proposed method involves three steps DC signal injection identification. In the first step, stator resistance is identified. second step assigned to leakage inductance rotor time constant extracted in third step. Based on identified all d-q an arbitrary reference frame...