Research On Photovoltaic Generation And Micro-grid Control Strategy

With the rapid development of globe economic, the scale of all industries is developed larger and larger. Therefore, the growth in electricity demand become more quickly. For now, the traditional power generation has some insurmountable disadvantages, large environment pollution, high cost of power grid construction, etc. While photovoltaic power generation can just be able to make up for the traditional power grid faults. But it’s a unstable energy source when connected to power grid. It will bring certain influence to power grid.In order to coordinate the contradiction between power grid and distributed power, the concept of micro grid arises at the historic moment.According to its operation modes, micro grid can be divided into isolated and connected micro power grid mode. To insure running coordinationally between these two modes, the choice of control related strategy becomes one of the key points. Only choose the right control mode, can reduce the conflict between the two modes, and that they can have the effect of mutual assistance.Firstly, this paper establishes the model of photovoltaic cells according analyzing the principle of photovoltaic power generation. Secondly through the Boost converter for disturbance observation method and conductance increment method is used for modeling, and comparing the differences between the two methods. Then starting from the micro grid operation control mode, respectively establishing the control strategy of simulation for the isolated and connected micro power grid. The isolated grid control strategies include V/f and Droop control strategy. The connected grid control strategies include P/Q control strategy and Dc voltage control. At last, on the basis of the simulation of active frequency shift in the island detection method, combinating the control mode switch for micro grid, analyzing the influence of the mode switch to the micro power grid.