In order to solve the problem of active power optimization being usually single-object oriented and the coordination between distributed generators (DGs) and traditional voltage control method being poor,a comprehensive voltage control optimization using the two-stage planning algorithm is proposed.Firstly,the differential evolution algorithm is used to obtain the feasible state when the status of under-load tap changer (ULTC) and shunt capacitors is determined by the second stage. Then the DG optimal output from the first stage is fed back to the second stage,and the optimal values of the objective function are calculated by the dynamic programming algorithm while the voltage control plan for day-ahead is obtained.Finally,the proposed method is implemented in MATLAB,its effectiveness in the coordination of DG output verified by simulation cases.

The information model is an abstract description of existing physical objects and their relationship in a system, such as the common information model(CIM) in IEC61970, which is provided with broad applicability in power system. In order to track the real-time operation state of the system, this paper proposes a novel method for the analysis of the area of vulnerability based on CIM, which is widely adopted in standardization for power dispatching automation system, and programs it. Firstly, the design scheme and CIM parse method are introduced in detail. Then a new fault positions method based on interpolation is proposed to calculate the area of vulnerability, which has higher precision and faster computation speed and could overcome the blindness of setting fault points. Finally, the graphic and data-based result of the area of vulnerability is provided.

The common information model CIM in IEC61970 standard is an abstract description of existing physical objects and their relationship in power system, which has been widely used in the construction of computer application systems of power system. In order to track the real-time operation state of power system when analyzing the area of vulnerability (AOV) to voltage sags, this paper proposes a novel method to obtain the data required by AOV analysis through parsing source data defined with CIM, and source data are from the SCADA system, equipment management system and management information system of safe production. The design scheme of AOV analysis using CIM is introduced, and method of parsing CIM is also provided. Finally, the method is applied to a regional power system of China, and graphic results of AOV are shown under balanced and unbalanced faults.

This paper proposes an information fusion method of Common Information Model(CIM) for analysis of sag vulnerability area, in order to automatically track the operation state of system. Multiplayer structure of information fusion containing data fusion, feature fusion and decision fusion, is built to obtain basic data required by analysis of sag vulnerability area like topologies, equipment parameters, the measured values of bus voltage, etc. Then the flow chart for calculating sag vulnerability area is given and fault position method based on interpolation is adopted. Finally, the method is applied to a large region grid and results show its possibility. Based on such a mode of sag vulnerability area analysis, it is also discussed for further application research.