The energe storage system with combination of large-scale grid-connected wind farms will be the developing trend of renewable energy in future. The flow battery has becoming the most potential advanced chemical energy storage technology among the storage method. This paper is mainly introducing about the work principle, characteristics and structure of the VRB system. Futhermore, the control mechanism of the power quality and stability used in wind farm connected to power grid by battery energy storage is illustrated in the end of paper.

The weight of evaluation index plays a key role in condition assessment and maintenance control of power transformer. A new approach of determination of comprehensive weight is proposed in this paper. The approach combines the entropy objective weight with the expert subjective weight together in a specific form, which not only avoids the situation that single weight determines the overall weight, but considers the primary and secondary problem between the two weights. The comprehensive weight calculated by this approach can reflect the place of every index in condition assessment of power transformer well. Empirical results show that the approach is reasonable and available.

In this work, a porcelain enamel coating material for high temperature resistant on 1Cr18Ni9Ti stainless steel is designed and processed. The structure and properties of the material are analyzed by SEM, EDAX, XRD and FTIR. The results show that the surface of the enamel glaze and the enamel coating are smooth and bright, there is no obvious crystallization characteristics in porcelain enamel. There is litter oxidation and inter-diffusion in the interface between 1Cr18Ni9Ti stainless steel and porcelain enamel coating material after coating enamel.

Since traditional power is non-renewable and unfriendly to environment, renewable energy power which overcomes defects of traditional energy will gradually replace the conventional thermal power. Based on the utilization problem of renewable energy in Smart Grid, this paper builds an Energy Internet which supports real-time, high-speed, two-way transmission of power data and more renewable energy. The Energy Internet achieves reliable two-way transmission of power and realizes intelligent management of the grid. This paper proposes the concept and characteristics of the Energy Internet and completes the design of the Energy Internet network structure and system components. Key issues, such as Renewable Energy Management System, energy storage devices, will be discussed, and finally the paper will point out the direction for further research.

In this paper, the problem about the distribution network planning considering distributed generators is researched. Firstly, distribution network planning model is formulated based on economy and security objectives. Secondly, an improved hybrid algorithm is proposed based on ant colony algorithm and genetic algorithm in order to get better performance. Finally, the method has been tested on a typical radial distribution system to demonstrate the effectiveness of the proposed method.