Effects of Wind Generation Uncertainty and Volatility on Power System Small Signal Stability

Shi, Li-Bao,Kang, Li,Yao, Liang-Zhong,Qin, Shi-Yao,Wang, Rui-Ming,Zhang, Jin-Ping The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

This paper discusses the impacts of large scale grid-connected wind farm equipped with permanent magnet synchronous generator (PMSG) on power system small signal stability (SSS) incorporating wind generation uncertainty and volatility. Firstly, a practical simplified PMSG model with rotor-flux-oriented control strategy applied is derived. In modeling PMSG generator side converter, the generator-voltage-oriented control strategy is utilized to implement the decoupled control of active and reactive power output. In modeling PMSG grid side converter, the grid-voltage-oriented control strategy is applied to realize the control of DC link voltage and the reactive power regulation. Based on the Weibull distribution of wind speed, the Monte Carlo simulation technique based is carried out on the IEEE 16-generator-68-bus test system as benchmark to study the impacts of wind generation uncertainty and volatility on small signal stability. Finally, some preliminary conclusions and comments are given.

Behavior of improved through-diaphragm connection to square tubular column under tensile loading

Qin, Ying,Zhang, Jing-Chen,Shi, Peng,Chen, Yi-Fu,Xu, Yao-Han,Shi, Zuo-Zheng 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.4

Square tubular columns are commonly used in moment resisting frames, while through-diaphragm connection is the most typical configuration detail to connect the H-shaped beam to the column. However, brittle fracture normally occurs at the complete joint penetration weld between the beam flange and the through-diaphragm due to the stress concentration caused by the geometrical discontinuity. Accordingly, three improved types of through-diaphragm are presented in this paper to provide smooth force flow path comparing to that of conventional connections. Tensile tests were conducted on four specimens and the results were analyzed in terms of failure modes, load-displacement response, yield and ultimate capacity, and initial stiffness. Furthermore, strain distributions on the through-diaphragm, the beam flange plate, and the column face were comprehensively evaluated and discussed. It was found that all the proposed three types of improved through-diaphragm connections were able to reduce the stress concentration in the welds between the beam flange and the through-diaphragm. Furthermore, the stress distribution in connection with longer tapered through-diaphragm was more uniform.

Tensile behavior of bolted through-diaphragm connections to SHS columns

Ying Qin,Jingchen Zhang,Yifu Chen,Peng Shi,Yaohan Xu,Zuozheng Shi 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.3

Steel hollow section (SHS) columns have been increasingly popular in structural systems due to high compressive capacity, excellent torsional strength, and symmetric bending stiffness. In moment-resisting frames, the structural performance of connections to SHS columns is important to ensure the ability to carry bending moment. Conventional connections utilize welds to connect the adjacent components to the columns. Brittle fracture often initiates at the welds and reduces the ductility of connections. In this research, bolted connections were proposed to connect the beam to the SHS column through through-diaphragm. Tensile tests were conducted on four specimens to evaluate the structural behavior of connections. Failure mode, load-displacement response, strength, stiffness, and ductility were analyzed. The test results showed that the specimens were failed by the necking down of the flange plate. All specimens had high load-carrying capacity and good ductility. Strain distributions at key locations were investigated to study the force flow path. The application of through-diaphragm was found to deliver the tensile load to larger area and thus reduced the stress concentration at the connecting zone. Moreover, large amount of stress was transferred directly through the diaphragm, and the required stress demand for the SHS column was decreased. Design method was then proposed to predict the yield and the ultimate strength of the bolted connections. Good agreement was found between the experimental results and the theoretical predictions.

Flexural Behavior of Anchor Horizontal Boundary Element in Steel Plate Shear Wall

Ying Qin,JinYu Lu,Li-Cheng-Xi Huang,Shi Cao 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.3

Steel plate shear walls (SPSWs) have been increasingly used in lateral load resisting system since the post-buckling strength of web plates was realized and considered in practical design. Diagonal tension field is formed in the web plate to resist the lateral force induced by winds and earthquakes. The force is anchored by the surrounded horizontal boundary elements (HBEs) and vertical boundary elements (VBEs) and eventually transferred to the ground. Therefore, the response of HBEs, especially anchor HBEs, is essential to ensure that SPSWs could exhibit the required strength, ductility, and energy dissipation capacity. This paper presents the results of theoretical studies into the flexural behavior of the anchor HBEs of SPSWs and can be regarded as an extension to the previous work by Qu and Bruneau (2011) and Qin et al. (2017). The boundary effect was considered to reflect the actual stress state at the HBE-to-VBE connection, which assembled the method by Qin et al. (2017). Furthermore, more proper distributions of the vertical component of tension field for the positive and negative flexure cases, respectively, were proposed comparing to the work by Qu and Bruneau (2011). The hand calculation approach for the plastic flexural capacity of the anchor HBEs was given by the summation of the contributions from the flanges and the web. The developed equations are compared with previous data and good agreement was found between them. Meanwhile, comprehensively discussions are conducted to evaluate the influence of key parameters on the flexural behavior of anchor HBE. It was found that the plastic flexural capacity of anchor HBE decreases from unity to the minimum as a result of the increase in shear force, axial force and vertical stresses. Moreover, the flexural response of anchor HBE is most vulnerable to the change in shear force. This indicates that boundary effect is significantly important and cannot be ignored in the analysis. The research in this paper provides basis for the capacity design of anchor HBE.

全球化时代的中国与海外华人

施雪琴(Shi Xue Qin) 전남대학교 글로벌디아스포라연구소 2011 전남대학교 세계한상문화연구단 국제학술회의 Vol.2011 No.2

Qiaoxiang, it means homeland of Chinese diaspora in China, which is mainly located in southern part of China and very special in China’s history as large number of people of this land emigrated to abroad, resulting in qiaoxiang has been characteristic of keeping close relations with overseas. qiaoxiang ties, a widely used term in describing the relations between qiaoxiang and overseas Chinese diaspora, has been coined in the field of the study of Chinese diaspora and became a significant factor in the interaction between qiaoxiang and overseas Chinese diaspora. Traditionally, qiaoxiang has been referred to southern provinces of China, mainly including Fujian (Min ?), Guangdong (Yue ?), where people has centuries long history of migrating to Southeast Asian region. As a result, people from Fujian and Guangdong constitutes the majority of the Chinese dispora in Southeast Asian area, and formed qiaoxiang ties linking Fujian & Guangdong with Southeast Asia. Thus, a primitive type of qiaoxiang ties is established on the basis of kin group & family clan and dialect group & cultural links. A lot of research has been done to demonstrate qiaoxiang ties is an important dynamics in promoting social economic development in qiaoxiang in the modem China, especially the avalanche of remittance from diaspora significantly promoted qiaoxiang’s modernization. With the implementation of policies of Reform and Opening to the outside world since 1978, in China, qiaoxiang ties has been revived and exploited by various levels of governments in China after nearly 30 years demonization. Firstly, under the guidance of Export Promotion Strategy sponsored by the central government, four SEZs (Special Economic Zones) have been set up in four famous qiaoxiang areas, including Zhuhai, Shenzhen, Shantou and Xiamen where are the homeland of large number of Chinese diaspora in Southeast Asia area and Hongkong as well as Macao, with the purpose to exploit diaspora’s capital, technology and overseas market network to promote the export of industrial products. The success of four SEZs has approved the availability of qiaoxiang ties, which encourage the central and local governments to further utilize diaspora to promote the Reform and Opening policy. As a result, qiaoxiang ties, which is viewed as a available and efficient way integrating overseas sources to promoting China’s economic modernization, has been copied and used widely around the whole China. It is worthy noted that, with the further development of policies of Reform and Opening, a large number of new Chinese diaspora are getting phenomenal around world, and among them there are emerging a large group of scientists and intellectuals in the developed countries, who are viewed as significant dynamics to promote China’s modernization in global era, thus, attracting these intellectuals back to China is becoming China’s new strategy in integrating diaspora into China’s development, resulting in the various brain projects launched by the levels of Chinese government. In the new strategy of integrating diaspora, various levels of government are becoming a key role in the re modeling qiaoxiang ties and re shaping the narrative of qiaoxiang ties. In conclusion, in today’s China, Chinese diaspora discourse is becoming heated and spreads into political, economic and cultural spheres, which demonstrate Chinese diaspora is being increasingly integrated in China’s socio economic development, and even being considered in the design of China’s foreign policy in the globalization era. Furthermore, qiaoxiang ties, featured with unique Chineseness in cultural dimension, is becoming increasingly an available media linking modernizing China and Overseas Chinese diaspora under the promotion of the all levels of government.

Further study on improvement on strain concentration in through-diaphragm connection

Ying Qin,Jing-Chen Zhang,Peng Shi,Yi-Fu Chen,Yao-Han Xu,Zuo-Zheng Shi 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.39 No.2

Hollow structural section (HSS) columns have been increasingly popular due to their structural and architectural merits. However, practical difficulty lies in developing proper connections. The through-diaphragm connections are considered as suitable connection type that is widely adopted in Asian countries. However, the stress concentration occurs at the location connecting through-diaphragm and steel beam. Furthermore, the actual load path from the beam flange is not uniformly transferred to the HSS column as conventionally assumed. In this paper, tensile tests were further conducted on three additional specimens with beam flange plate to evaluate the load versus displacement response. The load-displacement curves, yield and ultimate capacity, ductility ratio were obtained. Furthermore, the strain development at different loading levels was discussed comprehensively. It is shown that the studied connection configuration significantly reduces the stress concentration. Meanwhile, simplified trilinear load-displacement analytical model for specimen under tensile load was presented. Good agreement was found between the theoretical and experimental results.

東亞區域一體化與人口跨國遷移

施雪琴(Shi, Xue-Qin) 전남대학교 글로벌디아스포라연구소 2009 디아스포라 연구 Vol.3 No.1

China was a major migrant exporting country in the past centuries which has produced tens of millions of Chinese Diaspora who mainly concentrated in Southeast Asia countries. Since 1978 China opened up to outside world, Chinese" migrant to Southeast Asia has been increasing with the characteristic of feminization. Chinese women migration to Southeast Asia stands out Chinese migration culture and politics, which is not only an extension of historically civil association between China and Southeast Asia Countries, but also a result of normalization of diplomatic relationship and deepening economic cooperation between China and Southeast Asia. Generally speaking, Chinese female migrant in Southeast Asia is playing an important role in promoting the development of civil relationship between China and Southeast Asia, however, the issues brought about by Chinese female migrant in Southeast Asia such as Chinese doll syndrome as well as errant Chinese tourist are worthy of attention for both China and Southeast Asia countries.

Behavior of improved through-diaphragm connection to square tubular column under tensile loading

Ying Qin,Jing-Chen Zhang,Peng Shi,Yi-Fu Chen,Yao-Han Xu,Zuo-Zheng Shi 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.4

Square tubular columns are commonly used in moment resisting frames, while through-diaphragm connection is the most typical configuration detail to connect the H-shaped beam to the column. However, brittle fracture normally occurs at the complete joint penetration weld between the beam flange and the through-diaphragm due to the stress concentration caused by the geometrical discontinuity. Accordingly, three improved types of through-diaphragm are presented in this paper to provide smooth force flow path comparing to that of conventional connections. Tensile tests were conducted on four specimens and the results were analyzed in terms of failure modes, load-displacement response, yield and ultimate capacity, and initial stiffness. Furthermore, strain distributions on the through-diaphragm, the beam flange plate, and the column face were comprehensively evaluated and discussed. It was found that all the proposed three types of improved through-diaphragm connections were able to reduce the stress concentration in the welds between the beam flange and the through-diaphragm. Furthermore, the stress distribution in connection with longer tapered through-diaphragm was more uniform.

Polymorphisms in DNA Repair Genes and Risk of Glioma and Meningioma

Luo, Ke-Qin,Mu, Shi-Qing,Wu, Zhong-Xue,Shi, Yi-Ni,Peng, Ji-Cai Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Polymorphisms in DNA repair genes have been shown to influence DNA repair processes and to modify cancer susceptibility. Here we conducted a case-control study to assess the role of potential SNPs of DNA repair genes on the risk of glioma and meningioma. We included 297 cases and 458 cancer-free controls. Genotyping of XRCC1 Gln399Arg, XRCC1 Arg194Trp, XRCC2 Arg188His, XRCC3 Thr241Met, XRCC4 Ala247Ser, ERCC1 Asn118Asp, ERCC2 Lys751Gln and ERCC5 Asp1558His were performed in a 384-well plate format on the Sequenom MassARRAY platform. XRCC1 Arg194Trp (rs1799782) and ERCC2 Asp312Asn rs1799793 did not follow the HWE in control group, and genotype distributions of XRCC1 Gln399Arg rs25487, XRCC2 Arg188His rs3218536 and ERCC2 Asp312Asn rs1799793 were significantly different between cases and controls (P<0.05). We found XRCC1 399G/G, XRCC1 194 T/T and XRCC3 241T/T were associated with a higher risk when compared with the wild-type genotype. For ERCC5 Asp1558His, we found G/G genotype was associated with elevated susceptibility. In conclusion, our study has shown that XRCC1 Gln399Arg, XRCC1 Arg194Trp, XRCC3 Thr241Met and ERCC5 Asp1558His are associated with risk of gliomas and meningiomas. This finding could be useful in identifying the susceptibility genes for these cancers.

Effects of Wind Generation Uncertainty and Volatility on Power System Small Signal Stability

Li-Bao Shi,Li Kang,Liang-Zhong Yao,Shi-Yao Qin,Rui-Ming Wang,Jin-Ping Zhang 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

This paper discusses the impacts of large scale grid-connected wind farm equipped with permanent magnet synchronous generator (PMSG) on power system small signal stability (SSS) incorporating wind generation uncertainty and volatility. Firstly, a practical simplified PMSG model with rotor-flux-oriented control strategy applied is derived. In modeling PMSG generator side converter, the generator-voltage-oriented control strategy is utilized to implement the decoupled control of active and reactive power output. In modeling PMSG grid side converter, the grid-voltageoriented control strategy is applied to realize the control of DC link voltage and the reactive power regulation. Based on the Weibull distribution of wind speed, the Monte Carlo simulation technique based is carried out on the IEEE 16-generator-68-bus test system as benchmark to study the impacts of wind generation uncertainty and volatility on small signal stability. Finally, some preliminary conclusions and comments are given.