This paper presents a two-phase evaluation model called cluster analysis data envelopment analysis (CA-DEA) for renewable energy in power generation projects which combines cluster analysis and data envelopment analysis, to achieve the optimal resource exploitation sequence in the stage of planning and the effective evaluation during the period of operation. On the basis of a designed comprehensive evaluation index system, the fuzzy AHP is introduced to analyze the qualitative indices, such as the coordination level with local condition. The dominant factors can be determined by applying cluster analysis (CA); the non-parametric DEA model is adopted for the assessment of project input-output efficiency, which makes the production function determination easier. According to the comprehensive values of the ratio of input to output, the effective assessment to the performance of the projects could be implemented. Finally, a practical case is presented to verify the effectiveness and practicability of the model.

With the accelerated pace of the electric taxi,the growing charging power demand will have certain influence on the grid. As a precondition of safety operation for power grid,studies on electric taxies' charging load model is also the theoretical basis of electric taxi charging. Firstly,based on the analysis of Poisson process,random sequence of charging start time is expressed; then,the calculation model of electric taxi charging serving time is set up. Finally,charging power demand model of electric taxi is build. According to this model,electric taxi charging power curve within a day was calculated and presented with the operating data in a demonstration electric taxi charging station. The results of the simulation examples show that the modeling method of the charging power demand model is effective.

Power quality problems could cause enormous amounts of economic cost to electricity consumers. Taking voltage dips as an example, this paper presents a general overview of methods to quantify economic impact of power quality problems. It also presents in detail several ways how to collect power quality economic data. At last, suggestions on how such researches could be done in China are represented.

随着电动汽车的普及和发展,大规模的电动汽车充电将会给配电网带来一定地影响.科技部201 1年发布的国家十二五规划中预计,到2015年电动汽车保有量将达到100万辆.北京将在2015年前建设466个电动汽车充电站,以应对日益增加的电动汽车充电需求.

Energy storage capacity of batteries in an electric vehicle (EV) bring in lots of difference comparing with conventional electric power loads. These features provide new ideas for development of active distribution systems and renewable energy. In this paper, firstly, load model EV charging is established. Based on operation data from EV charging station, rules of EV charging are analyzed secondly. Considering human behavior, the features of EV charging compared with conventional load is summarized. In the end, combining features of EV charging and active distribution systems, applications of EVs in active distribution systems are explored. It can be expected that integration of EV will play an important role in active distribution systems in improving the shock resisting ability of power system, increasing operation efficiency and renewable energy penetration, as well as reducing construction cost.

With the accelerated pace of the electric bus, the growing charging power demand will have a certain influence on the grid. As a precondition of safety operation for power grid, studies on electric bus charging load model are also the theoretical basis of electric bus charging orderly. Firstly, based on the analysis of arriving time and state of energy, power demand model of electric bus charging station was set up. According to this model, electric buses charging station power curve within a day was calculated and presented with the operating data in a demonstration electric bus charging station. The results of the simulation examples show that the modeling method of the charging power demand model is effective.