Research on the Output Characteristics of Photovoltaic Array under the Non-Uniform Light

Abstract

The output characteristics of photovoltaic array was related with the topology of array, shadow distribution and illumination level. The theoretical analysis and simulation modeling of output characteristics of photovoltaic array including series array, parallel array and series-parallel array were made under the non-uniform illumination environment based on the circuit analysis. The photovoltaic cell was modeled by use of the improved two-diode model. Non uniform illumination is expanded from two illumination levels of traditional to N illumination levels and from the single series array to any number series-parallel array. The different analysis methods were adopted in different arrays for mathematical modeling and simulation. The current analysis was used in series arrays and voltage analysis used in parallel arrays. Analysis of current in branches and voltage between branches was used in series-parallel array. Then the mathematical models were established and programmed in m-file by MATLAB. The simulation models had a high computational accuracy, and were suitable for any simulation output characteristics of PV in different light environment and array topology. They could provide a theoretical basis for constructing the topological structure on the same condition and studying MPPT of PV array under non-uniform illumination.