Search

DL/T 684—2012 Guide of Calculating Settings of Relay Protection for Large Generator Transformer （hereinafter referred to as the “2012 Guide”） has played a significant role in improving the correct operation rate of relay protection devices for generator transformers and ensuring the safe operation of electrical equipment in power plants. However， with the increase in capacity of individual generator units in China and the emergence of new faults， the “2012 Guide” has proved inadequate， requiring revision to better guide engineering practice. Therefore， this paper analyzes the problems in the “2012 Guide” and puts forward specific revision suggestions to address problems such as misoperation of generator differential protection under sympathetic inrush current， misoperation of false power-on protection under poor synchronous conditions， and tripping of gap zero-sequence current protection of main transformer before reclosing in the case of transient single-phase ground faults on the line. The suggestions can provide reference for the revision of the “2012 Guide”.

Accurate estimation of the state of charge (SOC) of lithium battery is crucial to improve the dynamic performance and energy utilization of batteries. The method, the existing neural network are used to estimate SOC, has the problems of low accuracy and poor stability under complex working conditions. A new algorithm are proposed to estimate the SOC, which combines Transformer and Generative Adversarial Network (GAN), and the Variational Modal Decomposition (VMD). Firstly, as the excellent prediction ability of Transformer, Transformer is used as the generative network of GAN. Secondly, VMD is used to decompose the SOC historical data into six subsets to increase the input features. Finally, DST work data from the University of Maryland CALCE dataset is used for model training, and the VMD-Transformer-GAN algorithm is compared with LSTM, GRU, and BiLSTM algorithms for experiments. The experimental results show that the VMD-Transformer-GAN algorithm algorithmic estimation model has high stability and accuracy, which verifies the feasibility of the improved scheme.

In order to break through the surface analysis of the content structure of policy texts, an in-depth discussion of the linkage between regional policy makers and objectives is helpful to analyze the formation mechanism of policy effects. Through social network analysis and multi-index analysis, this study takes the QianwanNew Area of Ningbo and the Guangdong-Hong Kong-Macao Greater Bay Area as representatives to explore the policy framework for the sustainable development of manufacturing industry in the two bay areas respectively. Through the construction of government department cooperation network, policy keyword co-occurrence network, department keyword correlation network, and the analysis of network density, network centrality, structural holes, and cohesive subgroups, it is found that the impact results show great differences, which is related to the network structure of manufacturing policy text. [ABSTRACT FROM AUTHOR]

Background and purpose: Parkinson's disease is a common degenerative disease of the central nervous system with complex pathogenesis. More and more studies have found that inflammatory response promotes the occurrence and development of the disease, in which the activation of microglia plays an important role. PGC-1α (peroxisome proliferator activated receptor-γ coactivator-1α) is the main factor in mitochondrial biogenetic, and is closely related to the inflammatory response. Our immunofluorescence test results showed that PGC-1α and microglia (Iba1) have double-labeled phenomenon. The expression of microglia in the MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) group increased, and PGC-1α/Iba1 double label increased. To test whether lowering the expression of PGC-1α can reduce the activation of microglia and protect the substantia nigra dopaminergic neurons, we constructed PGC-1α interference lentivirus. Methods: Immunofluorescence, western blot, and ELISA were used to detect microglial phenotype. Results: The results showed that PGC-1α interfering with lentivirus can transfect microglial cells in substantia nigra, and the PGC-1α protein level decreased in substantia nigra accordingly; TH protein expression had no statistical difference compared with MPTP group; PGC-1α interfering lentivirus reduced microglia number and activation, and at the same time the expression of iNOS and Arg1 significantly reduced compared with MPTP group. The IL-6 expression in blood detected using ELISA was significantly reduced compared with MPTP group. Conclusion: PGC-1α downregulation inhibited microglia activity, and both M1 and M2 microglial activities are reduced. [ABSTRACT FROM AUTHOR]

This paper introduces policy incentive factors to explore their impact on innovation diffusion in enterprise clusters, and reveals the relationship between policy incentives and innovation adoption ratio through dynamic correlation simulation of policy incentive intensity and the type and scale of enterprise clusters. The research results show that policy incentives have short-term timeliness, and the impact of incentives over time will submerge the impact of interconnected enterprises, and its effect is related to the incentive evaluation value of related node enterprises. In the initial enterprise innovation is more, policy incentives can further enhance the overall innovation adoption ratio, while in the initial enterprise innovation is less, it can only decelerate recession. Besides, the effect of policy incentive is closely related to the type of enterprise cluster. The key factor of that is the choice of incentive intensity should match the type and scale of enterprise cluster. Moreover, the incentive intensity of traditional enterprise cluster is positively correlated with the scale of cluster, while the incentive intensity of innovative enterprise cluster is negatively correlated with the scale of cluster. In addition, the local incentive effect is better than that of overall incentives. Targeted incentives for limited target groups are more conducive to innovation diffusion. [ABSTRACT FROM AUTHOR]

Selective laser melting (SLM) is a promising manufacturing method for the construction of complicated precision parts. However, deformation of the overhang during the fabrication process and post treatment is still a common problem. In this paper, the effect of the scanning route on the residual stress and deformation of fabricated AlSi10Mg overhang specimens by SLM was investigated. Different scanning routes for the overhang including longitudinal direction, transverse direction, and the alternation between these two scanning routes in consecutive layers were studied by experiments within this study. Numerical simulation was utilized to measure the stress of the specimens while deformation prediction was used for the different scanning routes. Both the experimental and simulated results showed that the scanning route had a substantial influence on the residual stress and deformation of the specimens. The longitudinal scanning resulted in significant upward bending deformation of the overhang as it was cut from the baseplate. However, there was less deformation for the overhangs fabricated by transverse and alternating scanning routes. A transverse scanning route is helpful for the reduction of residual stress in the longitudinal direction and the corresponding deformation. [ABSTRACT FROM AUTHOR]