Research On Model System For Active Distribution Network With Distributed Energy Resources Integration

With the distributed energy resources (DER) integrated gradually, traditional distribution system planning and operation face substantial challenges and new requirements. The passive distribution network has to change into active distribution network (ADN) which has the possibility to interact with loads in managing local power flows in order to adapt the new situation. For this reason, the impacts of DER integration should be taken into account by planners and operators.This paper carries on a discussion of the impacts of DER integration and the methodology on DER connected to the grid. To facilitate the analysis of the ADN planning, operation issues and to establish relevant technical standards, there should be a uniform test system, which was provided with flexible network topology, low system losses and good applicability for load shifts. Therefore, a model system for ADN with DER integration is established, and a benchmark for MV distribution network of China is described in detail, which consists of network structure, line and transformer parameters as well as the resources connected to its nodes. The platform can be used to serve the analysis, design, and validation of methods for the network integration of DER.To well design the model system for operation economy and good adaptability to load shifts, a new method of choosing the right set of MV feeder sizes is adopted and two new definitions, namely economic load range and load reach are also accepted. The new method overcomes many shortcomings of the traditional method of choosing feeder section by economical current density, which not only can minimize the life cycle costs, but also ensure the feeder system with appropriate load reach under voltage limits. The capacity of power and distribution transformer is chosen in the same way. The model system can be used to analysis both economic and technical issues. Compare to thermal power generation, DER seems to be uneconomical when society and environment benefit are not to be taken into account. Therefore, the model system is more widely used for technical issues in present stage.In this paper, influence on distribution system losses and feeder voltage distribution with DER integration are choosen as examples to be analyzed and calculated with the purpose of studying how to minimize losses and maximize the quality of power supply of ADN. The results of simulation are accordant with theoretical analysis, which demonstrates the study is effective for energy conservation and improvement of network operating efficiency. Meanwhile, it is proved that the platform provides good assisting analysis function of ADN planning and operation.