Maximum Photovoltaic Penetration In Active Distribution Network Under Constraint Of Power Quality

Energy is an important strategic issue in the economic development of our country, and is the foundation of the sustainable development of economy and society in China. As the largest clean energy can be developed at present, solar energy resources have huge potential, and is a very promising way of resource utilization.With the rapid development of grid connected PV, the proportion of photovoltaic in distribution network is increasing day by day. When large scale PV connect to distribution network, the original one-way flow of radial passive distribution network will be transformed into multi-directional flow or even flow-reversed active distribution network. Moreover, since the energy transfer and conversion of photovoltaic power generation is based on the power electronic converter, the power output characteristics of PV are much different from the synchronous generators, which will cause serious power quality problems to traditional distribution network. And the larger the size of photovoltaic power generation, the more significant the effect of PV to the distribution network. So, the research on the maximum penetration of PV in a given power distribution network under the constraint of power quality is of urgent theoretical guiding significance to the construction and transformation of distribution network.Aiming at the problem of photovoltaic maximum penetration, the main work of this paper is as follows:1) Establish PV model for simulation research of distribution network, and the effect of photovoltaic (PV) connected to the distribution network were studied. Each node voltage and line current were calculated by three-phase power flow computation, and the effect of different location scenarios of photovoltaic and different penetration of photovoltaic on distribution network load node voltage deviation and voltage harmonic distortion is analyzed.2) different location models of photovoltaic are established, and the maximum photovoltaic penetration is calculated with several PV location scenarios under the constraint of voltage deviation and voltage harmonic distortion for several unbalanced distribution system in the OpenDSS platform. Based on this, the relationship between SVR, short circuit capacity and photovoltaic penetration is analyzed, and the corresponding rules are obtained.3) Giving full consideration to the voltage regulating ability of existing voltage regulating equipment in the distribution network. The partition strategy for SVR to regulating voltage is presented, on the basis of regulating voltage of SVR, the capacitor capacity is optimized with genetic algorithm, the maximum penetration of photovoltaic is further increased under the constraint of voltage with the proposed method and test method.The results of simulation shows that the penetration of photovoltaic is related with the line parameters of actual system. The closer the location of photovoltaic to the feeder source, the larger the penetration will be. For the cases considering the voltage and harmonic limits simulated, maximum photovoltaic penetration was at least 20% of peak load, and with the coordination between voltage regulating equipment and PV system, the penetration of PV will be increased significantly.The results of simulation shows that the penetration of photovoltaic is related with the line parameters of actual system. The closer the location of photovoltaic to the feeder source, the larger the penetration will be. For the cases considering the voltage and harmonic limits simulated, maximum photovoltaic penetration was at least 20% of peak load, and with the coordination between voltage regulating equipment and PV system, the penetration of PV will be increased significantly.