The Research Of Explicit Expression For The Two-Diode Model Of Solar Cells

Due to widely distributed, clean, without geographical restrictions and other unique advantages, solar photovoltaic power generation is developing rapidly in recent years. In order to make the solar photovoltaic power generation system to realize optimization design and operation, we need to use an accurate simulation model of solar photovoltaic power generation system to test to obtain related parameters. Solar photovoltaic component is the core part of the solar power system and also is the most valuable part of the solar power system. It is composed of multiple single solar cell according to the need to be up in series or parallel. Therefore, we need to model an accurate solar photovoltaic cell simulation model. The solar cell model usually has two kinds: single-diode model and two-diode model. The current-voltage( I ?V) characteristics of two models on the mathematical description are implicit and nonlinear. According to I ?V characteristic equation, the current(voltage) corresponding to different voltage(current) can be obtained by using numerical methods. However, even with relatively good initial guess, these numerical methods are often difficult to converge. Therefore, in the actual solar power system design and operation of application, design engineers need a simple, rapid and efficient solar cells explicit model.In this paper, we main research the explicit modeling method of solar cell models. Firstly, we propose a new analytical method to determine the series resistance of solar cells. Combined with other four parameter models(the shunt resistance, the saturation current, the photo current density, the ideality factor) proposed by other authors to effectively evaluate I ?V characteristics of single-diode model. Secondly, Taylor’s series expansion is used to express the exponential function of the two-diode model of solar cells and the explicit expression of two-diode model is obtained. Then we propose two new parameter extraction models based on Taylor’s series expansion. Finally, Padé approximants method is used to express the exponential function of the two-diode model of solar cells and the explicit expression of two-diode model is obtained. Then we propose two new parameter extraction models based on Padé approximants method. For the above proposed explicit modeling method, the silicon photovoltaic modules with different technology are tested. The simulation results shown that the models proposed in this paper are accurate, effective and feasible.