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Guan L.,China Electric Power Research Institute | Li B.,China Electric Power Research Institute | Cheng H.,China Electric Power Research Institute | Li J.,China Electric Power Research Institute | Li G.,China Electrical Power Equipment and Technology Co.
Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP | Year: 2012

In the HVDC transmission system, the valve side insulation of the converter transformer endures the AC and DC voltage simultaneously, and that could cause insulation failures in the converter transformer. Unfortunately, there is no method to simulate its working condition, so AC and DC test voltage are respectively imposed on the transformer during the factory test. There is a lack of research on the influences of AC and DC mixed voltage on the oil-pressboard insulation characteristics. In this paper a needle-plate electrode model is designed, and different values of AC and DC mixed voltage are imposed on the oil surrounded needle-plate electrode model to study the differences of breakdown characteristics. The test reveals different effects of AC and DC voltage component on the insulation model breakdown characteristics. The results indicate that, the AC breakdown voltage value decreases linearly as the DC pre-voltage value increases and vice versa. In addition, different pre-applied voltages affect the test results remarkably, that is, the breakdown voltage value under AC pre-voltage is higher than that under DC pre-voltage. © 2012 IEEE.

Zhang L.,Tianjin University | He J.,China Electrical Power Equipment and Technology Co.
Journal of Management in Engineering | Year: 2016

Sharing tacit knowledge is of great importance for an integrated project team to achieve success. However, research on the factors affecting tacit-knowledge sharing within an integrated project team has been insufficient in the construction management field. This paper aims to identify the critical factors affecting tacit-knowledge sharing and explore the interrelationships between these factors. Based on a literature review, the authors first identify 31 factors of tacit-knowledge sharing within integrated project teams. Through a questionnaire and statistical test, this research next analyzes the factors that are significant to tacit-knowledge sharing within an integrated project team. Then, factors analysis was used to study the critical factors of tacit-knowledge sharing. Finally, the authors analyze the interrelations among the critical factors and explore how they influence tacit-knowledge sharing within the integrated project team. The findings in this research demonstrate the impacts of trust on tacit-knowledge sharing with the evolution of trust taken into account. The authors also find that two personal factors are related to trust and tacit-knowledge sharing. This paper can provide useful guidance for an integrated project team to promote tacit-knowledge sharing and ultimately improve team performance. © 2015 American Society of Civil Engineers.

Zhang L.,Tianjin University | Zhang X.,China Electrical Power Equipment and Technology Co.
IEEE Transactions on Engineering Management | Year: 2015

Due to the characteristics of cross-functional teams, trust is crucial for cross-functional teams to enhance performance. However, as a significant factor, trust had been neglected in previous team performance models. In this paper, we investigate whether trust can be used as a predictor of cross-functional team performance by proposing a prediction model. The inputs of the model are both team structural and contextual (SC) factors, and project process (PP) factors, which are two major sources that form team trust. The output of the model is different levels of team performance, which consists of internal performance and external performance. The support vector machine techniques are used to establish the model. Results show that prediction accuracy is high (84.95%) when using both SC and PP factors as inputs, while PP factors have better prediction accuracy than SC factors on team performance and internal performance. It is suggested that team trust can be used as a good predictor of cross-functional team performance. In practice, this paper presents a better understanding of the relationship between trust and performance in cross-functional teams, and thus, enhances practitioners' managerial skills. It also gives reference for managers to dynamically control and predict team performance during project period. © 2015 IEEE.

Ma X.,Southwest Jiaotong University | Ma X.,National United Engineering Laboratory of Integrated and Intelligent Transportation | Xu Y.,China Electrical Power Equipment and Technology Co. | Li Y.,Southwest University for Nationalities
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

Logistics network assignment problem is an important research field on logistics optimization. According to user equilibrium theory, The equilibrium assignment framework of logistics network is a basic problem for it. The framework structure of logistics network consisted of carriers, logistics service providers, the shippers, and the modified wardrop user equilibrium of logistics network is proposed. Based on the modified UE condition, the optimum condition/equilibrium status of carriers, logistics service providers and the shippers in the equilibrium situation are analyzed. © ASCE.

Dong X.-M.,Shandong University | Liang J.,Shandong University | Han X.-S.,Shandong University | Yin H.-T.,China Electrical Power Equipment and Technology Co. | And 2 more authors.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012

In the conventional calculation of continuation power flow, resistances of transmission lines are assumed to be invariable, which is not true. The reason is that line resistance would be changed in terms of the temperature with the varying of the environment around and the power distribution. With this background, continuation power flow simulates a gradual varying process in which the change of line resistance must be considered, which makes the calculation have practical significance. In order to analyze the influence on continuation power flow calculation by change of line resistance, this paper presents the electro-thermal power flow model and electro-thermal continuation power flow model in which the line resistance is considered as state variable of power grid. In the models, line resistances are calculated and corrected for the consideration of electro-thermal coupling. The case study and comparison of the calculations by two methods show that there exist significantly differences of the results which must be brought to the forefront.

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