The electric vehicle charging station should be allocated based on traffic density, geographical distribution and other factors, and Voronoi diagram is adopted to set the service area of charging station. In combination with the actual situation of site selection of electric vehicle charging station, the comprehensive benefits index system is established. There are numerous factors influencing the site selection, among which there are uncertainty and fuzziness. The comprehensive evaluation method based on the fuzzy analysis and Analytical Hierarchy Process (AHP) is used to evaluate the comprehensive benefits in the site selection of electric vehicle charging stations, with the consultation of experts. This paper contributes to the best selection of comprehensive benefits and provides the reference for the decision-making of building the electric vehicle charging station. Actual examples show that the method proposed is effective.

Large-scale electric vehicle charging has a significant impact on power grid load, disorderly charging will increase power grid peak load. This article proposes an orderly charging mechanism based on TOU price. To build an orderly charging model by researching TOU price and user price reaction model. This article research the impact of electric vehicle charging on grid load by orderly charging model. With this model the grid's peak and valley characteristics, the utilization of charging equipment, the economics of grid operation can all be improved.

Nowadays with the improvement in the degree of emphasis on new energy, the wind power system has developed more and more rapidly over the world. Usually the wind plants are located in the remote areas which are far from the load centers. Generally series compensated AC transmission and high voltage DC transmission are made use of to improve the transmission capacity as two main effective ways which can solve the problem of large scale wind power transmission. The paper describes the three kinds of impact varieties and impact mechanisms in the sub-synchronous oscillation phenomena of wind power system based on doubly fed induction generator (DFIG) wind generators. At last, we point out the important problem that should be stressed in the wind power system.

The charger of electric vehicle is a power electronic device which consists of rectifying devices and DC-DC converters. This nonlinear diode rectifier circuit has low power factor and high harmonic content. In order to improve power factor and reduce the harmonic distortion rate of the AC side current, single-phase non-controlled rectifier charger needs to install the active power factor correction device. A piece of power system analysis software which is called PSCAD is used in modeling of an EV charger which contains Boost-APFC. By means of simulation and analysis, differences of APFC characteristics between the hysteresis current control mode and average current control mode which has an influence on the power grid are compared. The consequence of simulation shows that the two control strategies achieve power factor correction and harmonic reduction requirements; Boost type power conversion circuit employs the average current control mode is better, which has following features: relatively faster settling time of the output voltage, relatively smaller overshoot, lower current harmonic distortion rate on AC side, lower switching frequency and better control effect.

No abstract

No abstract