The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform
John Salmon - One of the best experts on this subject based on the ideXlab platform.
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Control and Analysis of a Modular Bridge for Battery Cell Voltage Balancing
IEEE Transactions on Power Electronics, 2018Co-Authors: Atrin Tavakoli, S. Ali Khajehoddin, John SalmonAbstract:A new distributed control scheme and charge flow analysis is presented for voltage balancing of series connected battery cells using nondissipative Modular power electronics. Each Modular Bridge is connected across two battery cells using a high frequency transformer and an asymmetrical half-Bridge. This results in using one switch and one diode per battery cell. IntraBridge charge transfer equalizes the voltage of two battery cells within a module using coupled transformer windings. Each Modular Bridge is connected to adjacent Bridges by connecting transformer windings within each module. This allows interBridge charge transfer and the balancing of pairs of battery cells, both within adjacent Bridge modules and modules more removed. The proposed controller uses a distributed control strategy whereby the control of each Modular Bridge monitors its own battery cell voltages and also those of adjacent Bridges, thus reducing the number of feedback sensors. Detailed analysis is presented that quantifies the flow of charge between a number of series connected battery cells ( $ N$ battery cells). A per-unit design methodology is used to illustrate the system charge flow characteristics. Simulations, design guidelines and experimental results are presented to validate the proposed method.
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A Modular Balancing Bridge for Series Connected Voltage Sources
IEEE Transactions on Power Electronics, 2014Co-Authors: J. Ewanchuk, John SalmonAbstract:The operation of a nondissipative cascaded Modular balancing Bridge is described for automatically balancing series connected voltage sources, such as lithium-ion battery cells or capacitors. Automatic voltage balancing is achieved using coupled inductors; Modularization and voltage balancing is achieved across N cells using cascaded transformers with coupled windings. The elementary Modular Bridge consists of four windings placed on a single core and is excited by an asymmetric half-Bridge. Two of these windings are used to automatically balance voltages across two voltage sources, while the remaining two windings magnetically cascade one Bridge with its neighboring Bridges to balance N voltage sources. This configuration allows for the voltage balancing of N voltage sources using N/2 identical transformers, and N/2 asymmetric Bridges. The voltage balancing action of the resultant magnetically coupled cascaded asymmetric Bridges can be broken into two categories: intraBridge voltage balancing (within a single Bridge) and interBridge voltage balancing (between neighboring Bridges). Design parameters relating to automatic voltage balancing are highlighted, as the approach is more cost effective than methods using directed, or individualized, voltage balancing of each voltage source. The physical size considerations of the four winding coupled inductor are discussed and a lithium-ion battery-based experimental prototype is used to verify simulated results.
Dean Bierwagen - One of the best experts on this subject based on the ideXlab platform.
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performance evaluation of longitudinal ultrahigh performance concrete closure pour connection for use in Modular Bridge construction pairwise comparison of capacity and ductility at failure limit state
Transportation Research Record, 2016Co-Authors: Yaohua Deng, Brent M Phares, Andrew J Putz, Curtis Carter, Michael Nop, Dean BierwagenAbstract:Accelerated Bridge construction techniques taking advantage of prefabricated Bridge elements and high-performance materials are being used more frequently for Bridge replacement projects. They result in minimal road closure times and traffic interruption and in the reconstruction of long-lasting highway Bridges. Longitudinal closure pour connections are an important deck-level component for Modular Bridge elements that are heavily stressed by traffic loadings and environmental effects and whose durability is a concern. To address cracking and leakage issues in such connections, the strength and failure modes of the longitudinal ultrahigh-performance concrete (UHPC) closure pour connection between adjacent prefabricated deck units were evaluated. First, specimens with and without a longitudinal UHPC closure pour connection were fabricated, instrumented, and tested. Finite element (FE) models were established to improve understanding of the behavior of the specimens under the loading condition. In addition,...
Gangbing Song - One of the best experts on this subject based on the ideXlab platform.
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monitoring fatigue damage of Modular Bridge expansion joints using piezoceramic transducers
Sensors, 2018Co-Authors: Tianyong Jiang, Yaowen Zhang, Lei Wang, Liang Zhang, Gangbing SongAbstract:Modular Bridge expansion joints (MBEJs) are commonly used in Bridges and are often subjected to fatigue damages, which necessitate fatigue monitoring of MBEJs to ensure the reliable operation of the Bridges. In this paper, a stress wave based active sensing approach using piezoceramic transducers is developed to monitor the fatigue damage of MBEJ. A MBEJ involves mainly center beam, edge beam, support bar, support box, sliding bearing, sliding spring, elastomeric strip seal, full-penetration weld and reinforcing plate. In practice, for a MBEJ, the part that is most prone to fatigue damage is the full-penetration weld between the center beam and the support bar. In this paper, a specimen, which is the full-scale center-beam/support-bar (CB/SB) assembly, was designed and fabricated to facilitate the experimental study. The assembly mainly includes center beam, support bar, reinforcing plate, and full-penetration weld. The lead zirconate titanate (PZT) transducer bonded on the support bar was used as the actuator and the PZT transducer mounted on the center beam was as the sensor. Dial indicators were utilized to measure the vertical displacement of the center beam. Two series of tests, including static test, and fatigue test, were performed on the specimen in an alternating fashion. Based on the number of cyclic loading, the experiment was divided into six different stages: 0th cycle (the healthy state), 0.8 million cycles, 1.6 million cycles, 2.4 million cycles, 3.2 million cycles, and 4 million cycles. The signals received by the PZT sensor were analyzed with the help of wavelet packet analysis. In addition, the structure stiffness also was considered as a comparative approach in this paper. Experimental results show that during the fatigue test, the structure stiffness decreases with the number of cycle loading. However, the method can only obtain the fatigue damage impact on the entire structure, and cannot determine the fatigue damage degree of a certain weld. On the other hand, the proposed method can accurately monitor the fatigue damage degree of full-penetration welds. The research results show that the developed piezoceramic enabled active sensing approach can monitor and estimate the fatigue damage in MBEJ in real-time.
Yaohua Deng - One of the best experts on this subject based on the ideXlab platform.
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performance evaluation of longitudinal ultrahigh performance concrete closure pour connection for use in Modular Bridge construction pairwise comparison of capacity and ductility at failure limit state
Transportation Research Record, 2016Co-Authors: Yaohua Deng, Brent M Phares, Andrew J Putz, Curtis Carter, Michael Nop, Dean BierwagenAbstract:Accelerated Bridge construction techniques taking advantage of prefabricated Bridge elements and high-performance materials are being used more frequently for Bridge replacement projects. They result in minimal road closure times and traffic interruption and in the reconstruction of long-lasting highway Bridges. Longitudinal closure pour connections are an important deck-level component for Modular Bridge elements that are heavily stressed by traffic loadings and environmental effects and whose durability is a concern. To address cracking and leakage issues in such connections, the strength and failure modes of the longitudinal ultrahigh-performance concrete (UHPC) closure pour connection between adjacent prefabricated deck units were evaluated. First, specimens with and without a longitudinal UHPC closure pour connection were fabricated, instrumented, and tested. Finite element (FE) models were established to improve understanding of the behavior of the specimens under the loading condition. In addition,...
Tianyong Jiang - One of the best experts on this subject based on the ideXlab platform.
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monitoring fatigue damage of Modular Bridge expansion joints using piezoceramic transducers
Sensors, 2018Co-Authors: Tianyong Jiang, Yaowen Zhang, Lei Wang, Liang Zhang, Gangbing SongAbstract:Modular Bridge expansion joints (MBEJs) are commonly used in Bridges and are often subjected to fatigue damages, which necessitate fatigue monitoring of MBEJs to ensure the reliable operation of the Bridges. In this paper, a stress wave based active sensing approach using piezoceramic transducers is developed to monitor the fatigue damage of MBEJ. A MBEJ involves mainly center beam, edge beam, support bar, support box, sliding bearing, sliding spring, elastomeric strip seal, full-penetration weld and reinforcing plate. In practice, for a MBEJ, the part that is most prone to fatigue damage is the full-penetration weld between the center beam and the support bar. In this paper, a specimen, which is the full-scale center-beam/support-bar (CB/SB) assembly, was designed and fabricated to facilitate the experimental study. The assembly mainly includes center beam, support bar, reinforcing plate, and full-penetration weld. The lead zirconate titanate (PZT) transducer bonded on the support bar was used as the actuator and the PZT transducer mounted on the center beam was as the sensor. Dial indicators were utilized to measure the vertical displacement of the center beam. Two series of tests, including static test, and fatigue test, were performed on the specimen in an alternating fashion. Based on the number of cyclic loading, the experiment was divided into six different stages: 0th cycle (the healthy state), 0.8 million cycles, 1.6 million cycles, 2.4 million cycles, 3.2 million cycles, and 4 million cycles. The signals received by the PZT sensor were analyzed with the help of wavelet packet analysis. In addition, the structure stiffness also was considered as a comparative approach in this paper. Experimental results show that during the fatigue test, the structure stiffness decreases with the number of cycle loading. However, the method can only obtain the fatigue damage impact on the entire structure, and cannot determine the fatigue damage degree of a certain weld. On the other hand, the proposed method can accurately monitor the fatigue damage degree of full-penetration welds. The research results show that the developed piezoceramic enabled active sensing approach can monitor and estimate the fatigue damage in MBEJ in real-time.