A magnitude-phase detection method for grid-connected PCC of distributed generation systems based on sequence decoupling

Author(s):  
Mengjie Kang ◽  
Ye Xu ◽  
Jinquan Wang ◽  
Jun Yan
2021 ◽  
Vol 11 (9) ◽  
pp. 3782
Author(s):  
Chu-Hui Lee ◽  
Chen-Wei Lin

Object detection is one of the important technologies in the field of computer vision. In the area of fashion apparel, object detection technology has various applications, such as apparel recognition, apparel detection, fashion recommendation, and online search. The recognition task is difficult for a computer because fashion apparel images have different characteristics of clothing appearance and material. Currently, fast and accurate object detection is the most important goal in this field. In this study, we proposed a two-phase fashion apparel detection method named YOLOv4-TPD (YOLOv4 Two-Phase Detection), based on the YOLOv4 algorithm, to address this challenge. The target categories for model detection were divided into the jacket, top, pants, skirt, and bag. According to the definition of inductive transfer learning, the purpose was to transfer the knowledge from the source domain to the target domain that could improve the effect of tasks in the target domain. Therefore, we used the two-phase training method to implement the transfer learning. Finally, the experimental results showed that the mAP of our model was better than the original YOLOv4 model through the two-phase transfer learning. The proposed model has multiple potential applications, such as an automatic labeling system, style retrieval, and similarity detection.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Manop Yingram ◽  
Suttichai Premrudeepreechacharn

The mainly used local islanding detection methods may be classified as active and passive methods. Passive methods do not perturb the system but they have larger nondetection zones, whereas active methods have smaller nondetection zones but they perturb the system. In this paper, a new hybrid method is proposed to solve this problem. An over/undervoltage (passive method) has been used to initiate an undervoltage shift (active method), which changes the undervoltage shift of inverter, when the passive method cannot have a clear discrimination between islanding and other events in the system. Simulation results on MATLAB/SIMULINK show that over/undervoltage and undervoltage shifts of hybrid islanding detection method are very effective because they can determine anti-islanding condition very fast.ΔP/P>38.41% could determine anti-islanding condition within 0.04 s;ΔP/P<-24.39% could determine anti-islanding condition within 0.04 s;-24.39%≤ΔP/P≤ 38.41% could determine anti-islanding condition within 0.08 s. This method perturbed the system, only in the case of-24.39% ≤ΔP/P ≤38.41% at which the control system of inverter injected a signal of undervoltage shift as necessary to check if the occurrence condition was an islanding condition or not.


2014 ◽  
Vol 933 ◽  
pp. 82-85
Author(s):  
Shi Feng Wang ◽  
Yi Xiang Yue ◽  
Jin Fang

In this paper, the actual operation of the superconducting motor and electrical parameters, a detailed analysis of the advantages and disadvantages of the existing quench detection method. After that I proposed an innovative detection method - voltage phase difference detection. On this basis, the design phase detection method based on the voltage difference quench detection and protection systems, based on stand-alone test and NI development platform test results, we verify its feasibility of the voltage phase difference detection method, and great superiority.


2020 ◽  
Vol 49 (4) ◽  
pp. 423002-423002
Author(s):  
佟星元 Xing-yuan TONG ◽  
闫晓光 Xiao-guang YAN ◽  
陈东 Dong CHEN

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