Advanced Materials Research Vols. 1070-1072

Abstract: In order to solve the problem of carrying out heavy loads up and down stairs for city residents who live in ordinary building without elevators, this paper designs a special small electric vehicle driven by storage battery, which has dual functions of climbing-stairs and driving over roads with a relatively quick speed based on a key mechanism—triple-wheel mechanism. The main structure and work principle of the small electric vehicle are given and analyzed at first. Then the driving speed over roads and the driving tortures of climbing stairs, which are essential data to design the powers of the driving motors, are calculated and analyzed. Finally the finite element analysis of the most fragile part-trident shaped part is analyzed and interpreted with a simulation model of the software—Solidworks. Due to the adequate and detailed calculations and analysis, the small electric vehicle with the dual functions designed by this paper can offer enough abilities to climb stairs with heavy loads and drive over roads with a considerable speed for residents who living in those buildings without elevators.

Abstract: A design of 100 kHz-1350 W electric vehicle DC/DC converter using LLC resonant converter with integrated transformer is presented. The loss analysis based on theoretical derivation is performed to reveal the loss distribution. Integrated magnetic structure is adopted in the design to further increase the efficiency and power density. A 280 V-360 V input, 13.5 V/100 A output prototype is built to verify its advantage, and the efficiency at 320 V input, 13.5 V/100 A output is 91.5% at the switching frequency of 100 kHz.

Abstract: There are altogether three magnetic components in the resonant tank of LLC resonant converter: the series resonant inductor, the parallel inductor and the transformer. The method to realize the magnetic integrated transformer in LLC resonant converter is presented. The design process is provided, and a magnetic integrated transformer is constructed and the test results correspond well with the design values. A prototype of 1350 W, 100 kHz LLC resonant converter type electric vehicle DC/DC converter equipped with the magnetic integrated transformer is built to verify the performance of the magnetic integrated transformer, and the efficiency at 320 V input, 13.5 V/100 A output is 91.5% at the switching frequency of 100 kHz.

Abstract: Through constructing the battery system of electric vehicle, real-time simulation model of V2G charging converter topology, and combined with material object of hardware and software of V2G charger controller, establishing semi-physical simulation platform for V2G electric vehicle charging system based on RT-LAB real-time systems, which making use of real-time simulation platform to research the control mechanism of charger controller. The experimental results show that: the constructed semi-physical simulation platform is running well, its simulation results of charging and discharging process is relatively consistent with the actual output of V2G charging equipment, it can be used to verify the developed adjustment mechanism of V2G charger and the charging and discharging process of a variety of electric vehicle battery system, provides an ideal semi-physical simulation platform for the verification of the control strategy of electric vehicle V2G charger.

Abstract: As a new type of transport, electric vehicles are becoming an important way to implement the energy and sustainable development of the city. Aiming at the Battery Swapping Stations (BSS) for electric buses, a strategy for coordinated charging is proposed to reduce the charging cost and decrease the load peak-valley difference of Distribution Network (DN). The load model of BSS is built based on the operation analysis of BSS and the charging data of batteries. The optimization of charging behavior imposed by the coordinated charging strategy is also presented. Finally, studies are carried out considering the Beitucheng BSS (for Beijing Olympic Games); analyses are also presented considering different number of batteries to take into account the actual configuration. Simulations show that the coordinated charging, vis-à-vis uncontrolled charging provides satisfactory results, not only reducing the charging cost but also decreasing the load peak-valley difference of DN.

Abstract: For the bottleneck of electric vehicle short range and energy supply inconvenience to restrain the fast development of electric vehicle, from the perspective of the electric vehicle power charging model, through analyzing the current situation and developing trend of electric vehicle charging facilities, consulting the existing electric vehicle charging model of advice, and borrowing from the mature business operation model of other domestic industry, one kind of proposal of suitable for the domestic electric vehicle current situation of power supply mode is analyzed. The proposal can provide reference for domestic electric vehicle scale and rapid development.

Abstract: New energy vehicles are becoming the future of auto industry and acquire considerable significance in many fields including energy conservation, CO2 emission reduction, environmental protection, oil dependence reduction, cultivation of new economic growth point, etc.. Based on international comparison and investigation to China’s two major auto industry bases----Changchun and Hubei, this paper discusses and analyzes, from economic point of view, the world new energy vehicle development and its experiences to China. Compares China’s new energy vehicle policies with relevant US policies. Analyzes the success of Belgian high tech and green plastic auto development. Illustrates, from consumers’ and companies’ view respectively, influence of China’s policies to the new energy vehicle development. Finally, summarizes the characteristics of China’s development, studies problems existing, and puts forward certain constructive suggestions.

Abstract: As a promising transport in the future, electric vehicles plays an important role in people's lives and energy conservation. In recent years, the rapid development of electric vehicles, inevitably causes the overload problems to the original grid. This paper presents a transformer load models with the consideration of electric vehicle charging load. We analyze the transformer overload problem by the results obtained by simulation of the model.

Abstract: Compared with power system, post insulators used in High-speed Electric Multiple Unit (EMU) have unique features such as limited space, low number of sheds and complex pantograph, which produces high electric field at some part of post insulators. When the insulators electric field exceeds a numerical value, it will produce corona discharge and reduce the reliability of High-speed EMU. At the same time, a distinct discharge phenomenon has been observed on the surface of the small curvature radius for pantograph. For guiding optimization of electric field for post insulators and pantograph, a simplified model of post insulators as well as the pantograph is established to calculate the distribution of potential and electric field based on ANSYS. Because the applied voltage cycle is far less than the relaxation time of the dielectric, electrostatic field module can be used in the ANSYS Simulation. By simulating, the maximum electric field is occurred at the pantograph angle and some measures should be taken to reduce the electric field to assure the reliability of the EMU. The potential would decrease along the axis of the post insulator and the first umbrella bear the largest voltage drop.

Abstract: Planning of charging stations for electric vehicles (EVs) is the foundation of EV’s promotion and development. A novel multi-objective optimization model is proposed in this paper to better locate and size the charging stations for EVs from given alternative sites. Economic costs of charging station and the time wasted in waiting for charging are minimized in the model. The capacity constraints of the charging stations are included as main constraints. Pareto front is used to compare and estimate the practical value of the current substation locating and sizing plans. A calculation method based on rasterization and Voronoi diagram is proposed to make it clear where the jurisdiction of each charging station ends. Finally, the proposed model and calculation method are verified using case study.