- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Effects of tilt angle between laser nozzle and substrate on bead morphology in multi-axis laser cladding
摘要： Laser cladding has been increasingly used for repairing and remanufacturing critical and high-value components due to its unique benefits such as high solidification rates and a small heat-affected zone. In laser cladding, tilt angle between a laser nozzle and a substrate has a significant impact on deposited bead morphology. To ensure the quality of laser cladding, the effects of tilt angle on bead morphology are investigated in this study. An analytical model is introduced to predict bead shapes for three tilting postures. In the first case, a substrate remains horizontal while the nozzle is tilted. All three parameters, including width, height, and peak point offset, will be influenced by the laser beam power distribution. In the second case, a substrate is tilted while the laser nozzle is kept axial to the substrate’s normal, the peak point offset will ascend along with the increasing of the tilt angle (gravity effect). In the third case, the laser nozzle remains vertical while the substrate is tilted, which leads to variations of cladding width, cladding height, and especially peak point shifting value. These parameters will be dependent on the integrated effect of gravity and the laser beam power distribution. A set of experiments is conducted to demonstrate the effectiveness of the proposed model. This study illustrates that the variation of cladding width and height with the tilt angle can be accurately calculated by the predictive model, and that the peak point shifting value is roughly smaller than 5% of cladding width when the tilt angle is less than 30°. These findings show that trajectory planning of multi-axis laser cladding can be optimized using an acceptable range of tilt angle between the laser nozzle and substrate.
关键词： Bead morphology,Laser beam power distribution,Laser cladding,Tilting posture,Gravity effect
更新于2025-11-28 14:24:20
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[IEEE 2019 IEEE Power & Energy Society General Meeting (PESGM) - Atlanta, GA, USA (2019.8.4-2019.8.8)] 2019 IEEE Power & Energy Society General Meeting (PESGM) - A New Remote Tap Position Estimation Approach for Open-Delta Step-Voltage Regulator in a Photovoltaic Integrated Distribution Network
摘要： We describe the general concept and practical feasibility of a dc-based open energy system (OES) that proposes an alternative way of exchanging intermittent energy between houses in a local community. Each house is equipped with a dc nanogrid, including photovoltaic panels and batteries. We extend these nanogrids with a bidirectional dc–dc converter and a network controller so that power can be exchanged between houses over an external dc power bus. In this way, demand-response fluctuations are absorbed not only by the local battery, but can be spread over all batteries in the system. By using a combination of voltage and current controlled units, we implemented a higher-level control software independent from the physical process. A further software layer for autonomous control handles power exchange based on a distributed multiagent system, using a peer-to-peer like architecture. In parallel to the software, we made a physical model of a four-node OES on which different power exchange strategies can be simulated and compared. First results show an improved solar replacement ratio, and thus a reduction of ac grid consumption thanks to power interchange. The concept’s feasibility has been demonstrated on the first three houses of a full-scale OES platform in Okinawa.
关键词： microgrid,power transmission,power system control,dc interconnected power system,smart grid,dc power distribution,DC–DC converter
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - System Level Assessment of the Impact of High Penetration of PV Inverters with Grid Support Capability on Distribution Networks
摘要： Power systems simulations using PSCAD have been performed to evaluate the impact to the distribution grid of high photovoltaic (PV) penetration. Voltage regulation at load nodes, feeder short-circuit currents and power losses have been analyzed for penetration level up to 60% and compared with a baseline case referring to as no PV. Results show that high PV penetration impacts residential area and non-residential area networks differently. Also, depending on the grid strength, the performance of the network is different. PV micro-inverters, in some cases, can prevent voltage excursion beyond tolerance limits however, they are more effective for power losses reduction. Overall, up to 15% in energy losses can be saved at very high penetration levels. Regarding the short-circuit levels no adjustment in the network infrastructures is required as the PV systems will have inconsequential contribution in feeder short-circuit currents.
关键词： power distribution,Power conversion,Photovoltaic power systems
更新于2025-09-23 15:21:01
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Photovoltaic-Driven SiC MOSFET Circuit Breaker with Latching and Current Limiting Capability
摘要： This paper introduces a Solid State Circuit Breaker with Latching and Current Limiting capabilities for DC distribution systems. The proposed circuit uses very few electronic parts and it is fully analog. A SiC N-MOSFET driven by a photovoltaic driver and a maximum current detector circuit are the core elements of the system. This work details circuit operation under different conditions and includes experimental validation at 1 kVdc. Wide versatility, highly configurable, and very fast response, less than 1 μs in the case of short-circuit, are the most remarkable outcomes.
关键词： SiC MOSFET,Solid State Circuit Breaker (SSCB),fault current limiter,WBG semiconductors,DC power distribution
更新于2025-09-23 15:21:01
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[IEEE IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium - Yokohama, Japan (2019.7.28-2019.8.2)] IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium - Results of Vibrational and Thermal Test for MOLI Laser Transmitter
摘要： Currently, self-healing is one of the most important functions in the smart grid. Meanwhile, fault detection, isolation, and restoration of feeder automation systems dominate the self-healing function in power distribution systems. The steps of the aforementioned function depend on the fault ?ag status of the feeder terminal unit. The conditions for setting this ?ag are judged by the feeder terminal unit overcurrent detecting curve. This paper found an ef?cient approach to calculate this curve via a half-interval method. Versatile application software with the curve plotting capability was also developed and deployed on the web server of the information-management department of Taiwan Power Company and is running successfully.
关键词： piecewise linear approximation,power distribution protection,IEEE standards,fault currents,Computer aided analysis
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE Power & Energy Society General Meeting (PESGM) - Atlanta, GA, USA (2019.8.4-2019.8.8)] 2019 IEEE Power & Energy Society General Meeting (PESGM) - A Combined Optimization Structure of Adaptive Neuro-fuzzy Inference System for Probabilistic Photovoltaic Power Forecasting
摘要： We describe the general concept and practical feasibility of a dc-based open energy system (OES) that proposes an alternative way of exchanging intermittent energy between houses in a local community. Each house is equipped with a dc nanogrid, including photovoltaic panels and batteries. We extend these nanogrids with a bidirectional dc–dc converter and a network controller so that power can be exchanged between houses over an external dc power bus. In this way, demand-response ?uctuations are absorbed not only by the local battery, but can be spread over all batteries in the system. By using a combination of voltage and current controlled units, we implemented a higher-level control software independent from the physical process. A further software layer for autonomous control handles power exchange based on a distributed multiagent system, using a peer-to-peer like architecture. In parallel to the software, we made a physical model of a four-node OES on which different power exchange strategies can be simulated and compared. First results show an improved solar replacement ratio, and thus a reduction of ac grid consumption thanks to power interchange. The concept’s feasibility has been demonstrated on the ?rst three houses of a full-scale OES platform in Okinawa.
关键词： dc power distribution,microgrid,DC–DC converter,power transmission,power system control,smart grid,dc interconnected power system
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Reformed Mesoporous Ge for Substrate Reuse in III-V Solar Cells
摘要： We describe the general concept and practical feasibility of a dc-based open energy system (OES) that proposes an alternative way of exchanging intermittent energy between houses in a local community. Each house is equipped with a dc nanogrid, including photovoltaic panels and batteries. We extend these nanogrids with a bidirectional dc–dc converter and a network controller so that power can be exchanged between houses over an external dc power bus. In this way, demand-response fluctuations are absorbed not only by the local battery, but can be spread over all batteries in the system. By using a combination of voltage and current controlled units, we implemented a higher-level control software independent from the physical process. A further software layer for autonomous control handles power exchange based on a distributed multiagent system, using a peer-to-peer like architecture. In parallel to the software, we made a physical model of a four-node OES on which different power exchange strategies can be simulated and compared. First results show an improved solar replacement ratio, and thus a reduction of ac grid consumption thanks to power interchange. The concept’s feasibility has been demonstrated on the first three houses of a full-scale OES platform in Okinawa.
关键词： microgrid,power transmission,power system control,dc interconnected power system,smart grid,dc power distribution,DC–DC converter
更新于2025-09-19 17:13:59
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[IEEE 2019 5th International Conference on Advances in Electrical Engineering (ICAEE) - Dhaka, Bangladesh (2019.9.26-2019.9.28)] 2019 5th International Conference on Advances in Electrical Engineering (ICAEE) - Comparative Study of Different Transformer-less Inverter Topologies for Grid-tied Photovoltaic System
摘要： An inductively coupled contactless dc connector has been proposed for the next-generation 380-V dc distribution system in data centers. A LLC resonant dc–dc converter topology with gallium nitride (GaN) power transistors has been applied to realize the short-distance highly ef?cient contactless power transfer. A prototype of a 1.2-kW 384- to 192-V connector has been fabricated and the conversion ef?ciency of over 95% with the power density of 8.1 W/cm3 has been con?rmed experimentally under 1000-kHz operation. The design consideration has been carried out and the potential to achieve 10.0 W/cm3 has been also shown taking the feature of the GaN power device and the characteristics of the magnetic core material for the transformer into account. The contactless dc connector integrates the functioning of an isolated dc–dc converter into a connector for space saving, and the dc current can be cut off without arc because of the inductive coupling. The proposed connector contributes to realizing a highly ef?cient, space saving, and reliable future 380-V dc distribution system.
关键词： Contactless power supply,dc–dc power converters,dc power distribution,gallium nitride (GaN)
更新于2025-09-19 17:13:59
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[IEEE 2017 IEEE 44th Photovoltaic Specialists Conference (PVSC) - Washington, DC (2017.6.25-2017.6.30)] 2017 IEEE 44th Photovoltaic Specialist Conference (PVSC) - Characterization and redesign of perovskite/silicon tandem cells
摘要： An inductively coupled contactless dc connector has been proposed for the next-generation 380-V dc distribution system in data centers. A LLC resonant dc–dc converter topology with gallium nitride (GaN) power transistors has been applied to realize the short-distance highly ef?cient contactless power transfer. A prototype of a 1.2-kW 384- to 192-V connector has been fabricated and the conversion ef?ciency of over 95% with the power density of 8.1 W/cm3 has been con?rmed experimentally under 1000-kHz operation. The design consideration has been carried out and the potential to achieve 10.0 W/cm3 has been also shown taking the feature of the GaN power device and the characteristics of the magnetic core material for the transformer into account. The contactless dc connector integrates the functioning of an isolated dc–dc converter into a connector for space saving, and the dc current can be cut off without arc because of the inductive coupling. The proposed connector contributes to realizing a highly ef?cient, space saving, and reliable future 380-V dc distribution system.
关键词： dc power distribution,Contactless power supply,dc–dc power converters,gallium nitride (GaN)
更新于2025-09-19 17:13:59
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Class F-C Power Amplifier with 2nd Harmonic Control at the Input
摘要： Currently, self-healing is one of the most important functions in the smart grid. Meanwhile, fault detection, isolation, and restoration of feeder automation systems dominate the self-healing function in power distribution systems. The steps of the aforementioned function depend on the fault ?ag status of the feeder terminal unit. The conditions for setting this ?ag are judged by the feeder terminal unit overcurrent detecting curve. This paper found an ef?cient approach to calculate this curve via a half-interval method. Versatile application software with the curve plotting capability was also developed and deployed on the web server of the information-management department of Taiwan Power Company and is running successfully.
关键词： piecewise linear approximation,power distribution protection,IEEE standards,fault currents,Computer aided analysis
更新于2025-09-19 17:13:59