Research And Design Of Solar Cell Simulator

Using the solar cell s imulator instead of the real so lar cell can greatly reduce theresearch cost of the solar system, shorten the research cyc le, and improve the researcheffic ie ncy. So, the study on so lar cell s imulator had become a n important researchcontent in the fields of solar photovoltaic power generation and application.The working princ iple o f solar cell was introduced firstly, and establis hed thesimulation model based on its equiva le nt c ircuit a nd engineering mathematicsmodel.The I-V, P-V characteristic c urves o f solar ce ll in sta ndard test condition andchanging environme nta l conditio ns had been simulated by means of the s imulationmodel. The above stud ies had la id a good foundation for the research of s imulatorsystem.Then, the merits and drawbacks of severa l algorithms commo nly used in so larce ll simulator had been ana lyzed. To overcome the shortcomings of trad itiona l pointby point approximation method in tracking speed and range of osc illation, a variablestep co mmand vo ltage point by point approximation method was put forward. Thismethod utilized the difference of load current and solar ce ll’s characteristic current tocontro l the duty ratio of BUCK circuit so as to adjust the output vo ltage of emulator,and make the working point of solar cell s imulator approach referenced working pointof I-V curve gradually, so that the simulation o f the outp ut characteristics of solar cellcould be achieved.In this study, a prototype of solar ce ll s imulato r was designed and produced byus ing DSP contro ller and BUCK circ uit. The working princip le of BUCK circ uit, DSPcontro ller’s A/D ca libration and protection circ uit were analyzed in detail, and thedesign and para meter calculatio n of hardware circuit were comp leted.In addition, thedesign method of software and the flow charts of ma in progra m as well as a kind ofsubprograms were also offered in this thesis.In order to verify the va lid ity o f the algorithm, the matlab simulating models andan experime nt prototype of the simulator were establis hed. The static and dyna miccharacteristics o f the algorithm were tested by means o f the s imulatio n and prototypeof simulator, while the load, light inte ns ity and enviro nmenta l te mperature werechanged. Besides, the comparison with the traditiona l algorithm was made. Accordingto experime nt data, the I-V, P-V curves of the solar cell were obtained, and the errorbetween theoretical data and experimenta l data were analyzed and calc ulated. It was indicated that the new algorithm can track the change of the reference working pointrapid ly and accurately, also can realize the co mplete I-V curve simulation underdifferent environme nta l conditions, and had better performance than traditio nal pointapproximation algorithm.