Time filter

Source Type

Shanghai, China

Shanghai Maritime University is a public university in Shanghai, People's Republic of China. Shanghai Maritime University is a multidisciplinary university with 6 fields of study: Engineering, Management, Economics, Literature, Science and Law. The university is one of the best Chinese universities for specialisation in maritime, shipping and transport education. Wikipedia.

Wang X.,University of Aalborg | Blaabjerg F.,University of Aalborg | Wu W.,Shanghai Maritime University
IEEE Transactions on Power Electronics

This paper addresses the harmonic stability caused by the interactions among the wideband control of power converters and passive components in an ac power-electronics-based power system. The impedance-based analytical approach is employed and expanded to a meshed and balanced three-phase network which is dominated by multiple current-and voltage-controlled inverters with LCL-and LC-filters. A method of deriving the impedance ratios for the different inverters is proposed by means of the nodal admittance matrix. Thus, the contribution of each inverter to the harmonic stability of the power system can be readily predicted through Nyquist diagrams. Time-domain simulations and experimental tests on a three-inverter-based power system are presented. The results validate the effectiveness of the theoretical approach. © 2014 IEEE. Source

Wu W.,Shanghai Maritime University | He Y.,Fsp Powerland Technology Inc. | Blaabjerg F.,University of Aalborg
IEEE Transactions on Power Electronics

This paper presents a new topology of higher order power filter for grid-tied voltage-source inverters, named the LLCL filter, which inserts a small inductor in the branch loop of the capacitor in the traditional LCL filter to compose a series resonant circuit at the switching frequency. Particularly, it can attenuate the switching-frequency current ripple components much better than an LCL filter, leading to a decrease in the total inductance and volume. Furthermore, by decreasing the inductance of a grid-side inductor, it raises the characteristic resonance frequency, which is beneficial to the inverter system control. The parameter design criteria of the proposed LLCL filter is also introduced. The comparative analysis and discussions regarding the traditional LCL filter and the proposed LLCL filter have been presented and evaluated through experiment on a 1.8-kW-single-phase grid-tied inverter prototype. © 2011 IEEE. Source

Chen W.,Shanghai Maritime University
Energy Conversion and Management

In this paper, a wet porous cooling plate has been utilized for building wall. Cooling can be achieved due to the evaporation in the porous plate. A mathematical model on the heat and mass transfer in the unsaturated porous media is developed to analyze the influences of ambient conditions and the porous plate thickness on the cooling performance of the porous evaporative plate. With a decreasing in ambient relative humidity and an increasing in ambient temperature, more cooling of the porous evaporative plate can be supplied for the inside of room. The heat exchange between the inside surface of the porous plate and the air in the room should be intensified to achieve a higher cooling efficiency of the porous plate. The ambient wind speed and the thickness of porous plate also have significance influences on the average temperature of the porous plate. All these results should be taken into account for the utilization of the porous evaporative cooling plate. © 2011 Elsevier Ltd. All rights reserved. Source

Zhang H.,Shanghai Maritime University | Zhang H.,Ohio State University | Shi Y.,Ohio State University | Wang J.,University of Victoria
IEEE Transactions on Fuzzy Systems

This paper focuses on the filter design for nonuniformly sampled nonlinear systems which can be approximated by Takagi-Sugeno (T-S) fuzzy systems. The sampling periods of the measurements are time varying, and the nonuniform observations of the outputs are modeled by a homogenous Markov chain. A mode-dependent estimator with a fast sampling frequency is proposed such that the estimation can track the signal to be estimated with the nonuniformly sampled outputs. The nonlinear systems are discretized with the fast sampling period. By using an augmentation technique, the corresponding stochastic estimation error system is obtained. By studying the stochastic stability and the energy-to-peak performance of the estimation error system, we derive the linear-matrix-inequality-based sufficient conditions. The parameters of the mode-dependent estimator can be calculated by using the proposed iterative algorithm. Two examples are used to demonstrate the design procedure and the efficacy of the proposed design method. © 2013 IEEE. Source

Hu Z.-H.,Shanghai Maritime University
Expert Systems with Applications

Various disasters with serious results are reported and happen around our lives. Most of them are unconventional contingency events. Emergency relief is an important activity dealing with the disasters to transfer a large number of materials to the destroyed places for casualties and reconstruction for the country, even the world. Container multimodal transportation will play an important role because of its superior characteristics. The relations in the process of supply and transportation build up the container supply chain. It is critical to schedule the multimodal transportation flow of the chain with time efficiency of higher reliability. In this study, the system of container multimodal transportation emergency relief is modeled as an affinity network inspired by the immune system. An integer linear programming model is proposed to build the path selection for container supply chain in the context of emergency relief. The simulation study shows the promising effects of the model. The study is valuable for designing the emergency logistics management system with optimal path selection and flow design of container supply chain in disaster environments. © 2010 Elsevier Ltd. All rights reserved. Source

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