Research On The Solar Cell Equation Explicit Approximate Solution

Since the photovoltaic effect was raised for the first time by humans, then the solar cellI-V characteristic was regard as the foundation of the solar cell theoretical research. And now,the solar cell I-V equation derived from the solid state physics is generally accepted. But theequation is an implicit transcendental equation, we can not express the current versus voltageor the voltage versus current with the elementary functions, which leads to the further troublefor the future research in calculation and derivation. Therefore, many researchers come upwith a lot of approach to obtain the explicit solution of the current or voltage. But we can seethat these expression which is achieved after mathematical treatment is complex, moreoverthe expression lacks of clear physical meaning, and furthermore the calculation precision isnot very high.For the previous studies raised by the predecessors is not comprehensive enough, thesolar cell equation approximate solution theory is presented in this paper, which is easy todraw the explicit expression of the current and voltage. Meanwhile the expression is of clearphysical meaning, and the expression parameter values are approximate to the initialparameter values of the solar cell I-V equation.Finally, in the paper, we use the theoretical model of the approximation solutionmentioned above to come up with the explicit expression of the maximum power current andvoltage. For the maximum power output problem of the solar cell, the processors havepresented three algorithms based on the maximum power tracking algorithm, but thesealgorithms have some deficiencies. Based on this, in the paper we present another trackingalgorithm: half step perturbation method.