PV system modeling and a global-planning design for its controller parameters

The conventional mathematic model of PV (Photovoltaic) cells contains logarithmic terms, which is not conducive to derivation calculation in small-signal modeling. The parameters of PV system are coupling due to its double-loop control method, and it's hard to precisely choose controller parameters. To solve these two problems above, this paper is based on PV system connected to an infinite power grid, uses the linear-fitting model of PV cells which is conducive to derivation instead of the original engineering one in small-signal modeling, and analyses the small-signal stability of the entire system. Meanwhile, a global-planning design for controller parameters is proposed to globally provide the optimal controller parameters. Simulation results show that the linear-fitting model of PV cells is very similar to the original engineering one, and the proposed design for controller parameters can provide a solution to calculate the global optimization.