32 research outputs found
15% reduction in AC loss of a 3-phase 1 MVA HTS transformer by exploiting asymmetric conductor critical current
An asymmetric dependence of the critical current on the direction of an applied magnetic field in HTS coated conductors has a non-trivial influence on the AC loss of coil windings. We report the modelled influence of real conductor critical current asymmetry on the AC loss characteristics of a 1 MVA HTS transformer design previously demonstrated by the Robinson Research Institute as well as a stand-alone coil having the same geometrical and electrical parameters as the low voltage (high current) winding of the transformer. We compare two commercial HTS conductors with distinctive differences in their critical current asymmetry and show a maximum variation of 15% and 29% in the calculated AC loss of the transformer and the stand-alone coil winding, respectively, when the conductor orientation is varied in the top and bottom halves of the windings. AC loss simulation giving consideration to asymmetric conductor critical current before winding the transformer could lead to substantial AC loss reduction even using the same amount of conductor and the same transformer design
DualVD: An Adaptive Dual Encoding Model for Deep Visual Understanding in Visual Dialogue
Different from Visual Question Answering task that requires to answer only
one question about an image, Visual Dialogue involves multiple questions which
cover a broad range of visual content that could be related to any objects,
relationships or semantics. The key challenge in Visual Dialogue task is thus
to learn a more comprehensive and semantic-rich image representation which may
have adaptive attentions on the image for variant questions. In this research,
we propose a novel model to depict an image from both visual and semantic
perspectives. Specifically, the visual view helps capture the appearance-level
information, including objects and their relationships, while the semantic view
enables the agent to understand high-level visual semantics from the whole
image to the local regions. Futhermore, on top of such multi-view image
features, we propose a feature selection framework which is able to adaptively
capture question-relevant information hierarchically in fine-grained level. The
proposed method achieved state-of-the-art results on benchmark Visual Dialogue
datasets. More importantly, we can tell which modality (visual or semantic) has
more contribution in answering the current question by visualizing the gate
values. It gives us insights in understanding of human cognition in Visual
Dialogue.Comment: Accepted by the Thirty-Fourth AAAI Conference on Artificial
Intelligence (AAAI-2020
Application of Flux Diverters in High Temperature Superconducting Transformer Windings for AC Loss Reduction
Flux diverters (FDs) are used in High Temperature Superconducting (HTS) transformers for AC loss reduction and flux optimization. In this paper, a 2D axial symmetric superconducting winding model is proposed and two designs of flux diverters are applied to the windings. A homogenization approach is used to analyze the windings with large turn numbers. The key parameters including the number, width, height and the spatial positions of the FDs are adjusted for AC loss and magnetic flux analysis. The means of obtaining optimum designs of the FDs is provided and can be used to develop new winding designs with FDs, which contributes to better electromagnetic performance and higher efficiency of HTS transformers
XLM-K: Improving Cross-Lingual Language Model Pre-training with Multilingual Knowledge
Cross-lingual pre-training has achieved great successes using monolingual and
bilingual plain text corpora. However, most pre-trained models neglect
multilingual knowledge, which is language agnostic but comprises abundant
cross-lingual structure alignment. In this paper, we propose XLM-K, a
cross-lingual language model incorporating multilingual knowledge in
pre-training. XLM-K augments existing multilingual pre-training with two
knowledge tasks, namely Masked Entity Prediction Task and Object Entailment
Task. We evaluate XLM-K on MLQA, NER and XNLI. Experimental results clearly
demonstrate significant improvements over existing multilingual language
models. The results on MLQA and NER exhibit the superiority of XLM-K in
knowledge related tasks. The success in XNLI shows a better cross-lingual
transferability obtained in XLM-K. What is more, we provide a detailed probing
analysis to confirm the desired knowledge captured in our pre-training regimen.
The code is available at
https://github.com/microsoft/Unicoder/tree/master/pretraining/xlmk.Comment: AAAI-202
Application of Flux Diverters in High Temperature Superconducting Transformer Windings for AC Loss Reduction
Flux diverters (FDs) are used in High Temperature Superconducting (HTS) transformers for AC loss reduction and flux optimization. In this paper, a 2D axial symmetric superconducting winding model is proposed and two designs of flux diverters are applied to the windings. A homogenization approach is used to analyze the windings with large turn numbers. The key parameters including the number, width, height and the spatial positions of the FDs are adjusted for AC loss and magnetic flux analysis. The means of obtaining optimum designs of the FDs is provided and can be used to develop new winding designs with FDs, which contributes to better electromagnetic performance and higher efficiency of HTS transformers.</p
Study on Outlet Temperature Control of External Receiver for Solar Power Tower
Due to the change of direct normal irradiance (DNI) and the change of output power load, the receiver of the solar tower is in an unstable state in the actual operation. In this paper, a 100 MW external cylindric receiver is designed and modelled. The dynamic and comprehensive model is established for the receiver, including the thermal and mechanical equations. The temperature control strategy is applied to the receiver model. The validity of the control strategy is verified by disturbance experiments, including DNI, the inlet temperature of the heat transfer fluid (HTF), and the weather data on a cloudy day. The response characteristics of the receiver are demonstrated. Its thermal lag characteristics and restraining effect on the fluctuating environment are revealed. The dangerous occasion of the receiver during operation are detected, including the overheat of the local panel, and the dissociation point of the molten salt. Both the robustness and the deficiency of the control strategy of the receiver are pointed out. The research results will contribute to the control strategy formulation of the SPT (solar power tower) station