| 1. |
- Aranda, Jesus Javier Lechuga, et al.
(författare)
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A space-coiling resonator for improved energy harvesting in fluid power systems
- 2019
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Ingår i: Sensors and Actuators A-Physical. - Elsevier : Elsevier. - 0924-4247 .- 1873-3069. ; 291, s. 58-67
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Tidskriftsartikel (refereegranskat)abstract
- Pressure fluctuation energy harvesting devices are promising alternatives to power up wireless sensors in fluid power systems. In past studies, classical Helmholtz resonators have been used to enhance the energy harvesting capabilities of these harvesters. Nevertheless, for fluctuations with frequency components in the range of less than 1000 Hz, the design of compact resonators is difficult, mostly for their poor acoustic gain. This paper introduces a space-coiling resonator fabricated using 3D printing techniques. The proposed resonator can achieve a better acoustic gain bounded by a small bulk volume compared to a classic Helmholtz resonator, improving the energy harvesting capabilities of pressure fluctuation energy harvesters. The resonator is designed and evaluated using finite-element-method techniques and examined experimentally. Three space-coiling-resonators are designed, manufactured and compared to classic Helmholtz resonators for three frequencies: 280 Hz, 480 Hz and 920 Hz. This work displays the possibility of compact, high-performance pressure fluctuation energy harvesters and the advantages of the space-coiling printed resonators to enhance the harvesting performance.
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| 2. |
- Aranda, Jesus Javier Lechuga, et al.
(författare)
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An Apparatus For The Performance Estimation Of Pressure Fluctuation Energy Harvesters
- 2018
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : IEEE. - 0018-9456 .- 1557-9662. ; 67:11, s. 2705-2713
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Tidskriftsartikel (refereegranskat)abstract
- Hydraulic pressure fluctuation energy harvesters are promising alternatives to power up wireless sensor nodes in hydraulic systems. The characterization of these harvesters under dynamic and band-limited pressure signals is imperative for the research and development of novel concepts. To generate and control these signals in a hydraulic medium, a versatile apparatus capable of reproducing pressure signals is proposed. In this paper, a comprehensive discussion of the design considerations for this apparatus and its performance is given. The suggested setup enables the investigation of devices tailored for the harvesting of energy in conventional hydraulic systems. To mimic these systems, static pressures can be tuned up to 300 bar, and the pressure amplitudes with a maximum of 28 Bar at 40 Hz and 0.5 bar at 1000 Hz can be generated. In addition, pressure signals found in commercial hydraulic systems can be reproduced with good accuracy. This apparatus proves to be an accessible, robust, and versatile experimental setup to create environments for the complete performance estimation of pressure fluctuation energy harvesters.
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| 3. |
- Aranda, Jesus Javier Lechuga, et al.
(författare)
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Fluid coupling interfaces for hydraulic pressure energy harvesters
- 2017
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Ingår i: 2017 IEEE International Conference on Advanced Intelligent Mechatronics (AIM). - : IEEE. - 9781509059980 ; , s. 1556-1562
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Konferensbidrag (refereegranskat)abstract
- The need for wireless sensor networks that can run for long times without the need of battery replacement has risen the need for energy harvesters. Industrial environments have plenty of energy sources that can be harvested; pressure fluctuations are a high energy density source that can be harvested using piezoelectric devices. Present devices have introduced flat metallic plates as the main force transmission elements for hydraulic fluctuations energy harvesters. In this paper, we analyze the force transmission efficiency of flat plates when used as the primary fluid coupling interface in hydraulic energy harvesters. Previous work has been focused on the optimization of circuit matching and pressure ripple amplification. In this work, we offer a look into the efficiencies of flat plates in different configurations and pressure loads. The analysis shows that despite the reasonable force transmission efficiency of flat plates in low-pressure environments, the overall efficiency of hydraulic energy harvesters can be improved if instead of flat plates, conventional hydraulic actuators, such as piston cylinders, could be used.
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| 4. |
- Aranda, Jesus Javier Lechuga, et al.
(författare)
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Force Transmission Interfaces for Pressure Fluctuation Energy Harvesters
- 2018
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Ingår i: IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society. - : IEEE. - 9781509066841 ; , s. 4230-4235
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Konferensbidrag (refereegranskat)abstract
- Wireless sensor nodes in state of the art fluid power systems used in monitoring and maintenance prediction demand long lasting power sources that do not rely on batteries. Energy harvesting is a promising technology that can provide the required energy to power wireless sensors. Pressure fluctuation energy harvesters can be employed in conventional hydraulic systems to convert the acoustic pressure fluctuation to electrical power. Present studies have explored the overall efficiency of these devices while experimentally describing losses in piezoelectric and circuit interfaces, nevertheless there is no study on the fluid to mechanical force transmission efficiency. In this paper we investigate the pressure to force transmission rate of two types of fluid to mechanical interfaces: a flat metal plate and a conventional hydraulic piston. The interfaces are investigated in conditions similar to those found in conventional hydraulic systems. The study shows that flat plate exhibit good force transmission for low pressure applications with a constant rate across frequencies, while exhibiting a decrease in force transmission at higher pressures. On the other hand the piston exhibit a more robust pressure design, with a constant force transmission rate at all pressures but with a dampening of force at higher frequencies. It is shown that small differences in force transmission ratios can have a considerable impact on the power generation.
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| 5. |
- Bader, Sebastian, 1984-, et al.
(författare)
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A concept for remotely reconfigurable solar energy harvesting testbeds
- 2017
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Ingår i: Proceedings of IEEE Sensors. - : IEEE. - 9781509010127 ; , s. 837-839
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Konferensbidrag (refereegranskat)abstract
- Existing solar energy harvesting systems are typically evaluated with a single configuration. However, results on different harvester configurations are often desired in order to select the appropriate match to specific ambient conditions and application requirements. In this paper, we therefore present a concept for remotely reconfigurable solar energy harvesting testbeds, which allows for multiple harvester configurations to be evaluated with a single system deployment. We demonstrate that such a testbed can be implemented in an efficient manner by utilizing the benefits of wireless sensor networks, resulting in a scalable and flexible system with low power consumption.
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| 6. |
- Bader, Sebastian, 1984-, et al.
(författare)
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One-diode photovoltaic model parameters at indoor illumination levels – A comparison
- 2019
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Ingår i: Solar Energy. - : Elsevier BV. - 0038-092X .- 1471-1257. ; 180, s. 707-716
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Tidskriftsartikel (refereegranskat)abstract
- Models of photovoltaic devices are used to compare the properties of photovoltaic cells and panels, and to predict their I-V characteristics. To a large extent, modeling methods are based on the one-diode equivalent circuit. Although much research exists on the implementation and evaluation of these methods for typical outdoor conditions, their performance at indoor illumination levels is largely unknown. Consequently, this work performs a systematic study of methods for the parameter extraction of one-diode models under indoor conditions. We selected, reviewed and implemented commonly used methods, and compared their performance at different illumination levels. We have shown that most methods can achieve good accuracies with extracted parameters regardless of the illumination condition, but their accuracies vary significantly when the parameters are scaled to other conditions. We conclude that the physical interpretation of extracted parameters at low illumination is to a large extent questionable, which explains errors based on standard scaling approaches.
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| 7. |
- Cheng, Peng, et al.
(författare)
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Torque sensor
- 2018
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Patent (populärvet., debatt m.m.)abstract
- The present invention relates to a torque sensor (1) comprising a body (2), at least one airtight chamber (3) provided in the body, a pressure sensor (4) measuring 1 the pressure in said at least one airtight chamber, and a pressure to torque converter (5) connected with the pressure sensor. Each airtight chamber is arranged to change its volume when the body is subjected to a torque, wherein the volume change causes a change of pressure of the enclosed air in the airtight chamber. The change of pressure is detected and converted to the corresponding torque.
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| 8. |
- Cheng, Peng, et al.
(författare)
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Torque Sensor Based on Differential Air Pressure Using Volumetric Strain
- 2017
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 17:11, s. 3269-3277
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Tidskriftsartikel (refereegranskat)abstract
- This paper proposes a torque sensor based on the differential air pressure measurement method using the volumetric strain of a mechanical sensing structure. A model of the measurement system based on the differential air pressure from the volumetric strain of the mechanical sensing structure is proposed and theoretically discussed. The error sources are identified and an error propagation model is presented for the proposed torque measurement method. Considering these error sources, a prototype torque sensor is presented as a case study for the method verification. Both the mechanical and readout electronics designs are discussed and analyzed. The mechanical sensitivity, resolution, and maximum stresses are analyzed using finite-element modeling. Based on the results from the simulation, a prototype torque sensor is manufactured and experimentally verified using a readout electronics design. For verification, the sensor prototype is measured under static torque to have a sensitivity of 0.04272V/N. m and a range of +/- 117N . m. Compared with the nominal mechanical sensitivity result from the FEM simulation, this measured sensitivity has a difference less than 6%. The noise analysis of the designed readout electronics shows that the resolution of 0.006% can be achieved with this design. Furthermore, hysteresis analysis shows an error of 0.012% of full scale. From these results, it is also shown that the actual performance of the sensor is mainly limited by the differential pressure sensor and the readout electronics design and is not by the mechanical design of the sensor.
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| 9. |
- Gebben, Florian, et al.
(författare)
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Configuring artificial neural networks for the prediction of available energy in solar-powered sensor nodes
- 2015
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Ingår i: 2015 IEEE SENSORS - Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 354-357
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Konferensbidrag (refereegranskat)abstract
- The behavior prediction of solar energy harvesting systems requires accurate system models in order to dimension the system with respect to its application and location constraints. In contrast to commonly used equivalent circuit models, artificial neural networks (ANN) allow for the behavior of the entire system to be captured in an efficient manner. In this work, we have investigated the influences of the underlying ANN configuration on the model's prediction performance. It was found that the performance variation between training runs increases with an rising number of neurons, which can lead to a higher model performance, but makes the performance outcome more sensitive to initial training conditions. Moreover, the results demonstrate that even simple ANN configurations capture the system behavior accurately and result in low prediction errors for the harvesting architecture under test.
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| 10. |
- Haller, Stefan, 1982-, et al.
(författare)
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A 2.5 v 600 a mosfet-based DC traction motor
- 2019
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Ingår i: Proceedings of the IEEE International Conference on Industrial Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538663769 ; , s. 213-218
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Konferensbidrag (refereegranskat)abstract
- A high copper fill factor allows reducing the resistive losses responsible for more than 50 % of the losses in today's most commonly used electrical motors. Single-turn windings achieve a copper fill factor close to one. Furthermore, they do not suffer from turn to turn faults and provide a low thermal resistance between winding and stator. The reduced EMF of single-turn winding configurations promotes the use of extra-low voltage high current MOSFETs. Rapid development of these MOSFETs allows reversing common design principles to explore new applications, such as battery electric traction drives. This paper presents a 2.5 V 1 kW MOSFET driven 13-phase permanent magnet DC motor with a single-turn winding configuration. The motor prototype with a copper fill factor of 0.84 was tested with continuous drive currents up to 600 A. The measured torque-efficiency map shows that such a high-current concept with voltages below 60 V is feasible using today's extremely low-voltage high current semiconductors. Due to the rapid development of such switches, there is great potential in this concept for further improvements. This work presents a small-scale version of the high-current drive, which is part of the development of an extra-low voltage traction drive concept.
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