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• Proposing the DC cable axial temperature field as an evaluation condition for DC cable operation. • A high-fidelity digital twin model is built for the DC cable. • Investigating the impact of fast and accurate computation with Sequence-to-Sequence residual neural networks is crucial for the prediction and maintenance of digital twin models. • Accuracy can be guaranteed while achieving millisecond-level calculations. The most important features of digital twin technology for transmission and transformation equipment are symbiotic evolution and state prediction. In constructing the digital twin model for DC cables, the transient and steady-state temperature fields need to be considered comprehensively in the modeling process to consider the multi-physical field coupling, mathematical model, operational data, and environmental conditions in specific cases, which makes it difficult to satisfy the real-time requirements of the digital twin. To solve this problem, in this paper, a digital twin technology architecture for DC cables is proposed, and a neural network learning model is constructed to minimize the latency due to the complexity of the model simulation. Moreover, an efficient digital twin model that is based on the model-driven approach is developed for the fast computation of the axial temperature field of DC cables. The use of the Sequence-to-Sequence residual neural network algorithm for the reduced-order multi-physics field coupling modeling reduces the computational time and ensures as much accuracy as possible up to the finite element model simulation. The simulation results show that the use of the digital twin model reduces the simulation time from 275 s to 0.56 s, and the relative error between the accuracy of the digital twin model and the finite element model for the axial temperature field of the DC cable is 0.46 %. Finally, verification of the reasonableness and feasibility of the proposed method is carried out via an experimental platform according to the standard of CIGRE TB496. In particular, the maximum value of the DC cable temperature is verified to have a small error compared with the result of the Sequence-to-Sequence calculation under specific working conditions. [ABSTRACT FROM AUTHOR]

Standard Clocks in the primordial epoch leave a special type of features in the primordial perturbations, which can be used to directly measure the scale factor of the primordial universe as a function of time a ( t ) , thus discriminating between inflation and alternatives. We have started to search for such signals in the Planck 2013 data using the key predictions of the Standard Clock. In this Letter, we summarize the key predictions of the Standard Clock and present an interesting candidate example in Planck 2013 data. Motivated by this candidate, we construct and compute full Standard Clock models and use the more complete prediction to make more extensive comparison with data. Although this candidate is not yet statistically significant, we use it to illustrate how Standard Clocks appear in Cosmic Microwave Background (CMB) and how they can be further tested by future data. We also use it to motivate more detailed theoretical model building. [ABSTRACT FROM AUTHOR]

Abstract: Experimentally distinguishing different primordial universe paradigms that lead to the Big Bang model is an outstanding challenge in modern cosmology and astrophysics. We show that a generic type of signals that exist in primordial universe models can be used for such purpose. These signals are induced by tiny oscillations of massive fields and manifest as features in primordial density perturbations. They are capable of recording the time-dependence of the scale factor of the primordial universe, and therefore provide direct evidence for specific paradigm. These signals present special opportunities and challenges for experiments and data analyses. [Copyright &y& Elsevier]

Abstract: We discuss the Montonen–Olive electric–magnetic duality for the BPS massless monopole clouds in supersymmetric Yang–Mills theory with non-Abelian unbroken gauge symmetries. We argue that these low energy non-Abelian clouds can be identified as the duals of the infrared bremsstrahlung radiation of the non-Abelian massless particles. After we break the supersymmetry to by adding a superpotential, or to by further adding soft breaking terms, these non-Abelian clouds will generally condense and screen the non-Abelian charges of the massive monopole probes. The effective mass of these dual non-Abelian states is likely to persist as we lower the energy to the QCD scale, if all the non-Abelian Higgs particles are massive. This can be regarded as a manifestation of the non-Abelian dual Meissner effect above the QCD scale, and we expect it to continuously connect with the confinement as we lower the supersymmetry breaking scale to the QCD scale. [Copyright &y& Elsevier]

Given its small chip area and high current density, the fault protection of SiC MOSFET is a serious challenge. In this paper, a gate voltage-based fault protection method for a SiC MOSFET subjected to short circuit type II also called fault under load is proposed. The circuit implementation of the proposed method is analyzed in detail. A test with a voltage of 200 V is conducted. Experimental results verify the effectiveness of the proposed method. It is exhibited the fault response time of the proposed method is less than 1 μs, which is very fast to protect a device and is conducive to the reliable and safe operation of SiC MOSFETs. [ABSTRACT FROM AUTHOR]