This paper presents the modeling of photovoltaic power system elements. The solar cell is modeled mathematically for determining its electrical behavior. Current voltage and power voltage characteristics of each solar cell are determined by aiding of the model at different isolation levels. The solar cell model is then extended to obtain the module along with the array model. Experimental verification of the model indicates a good fitting of the model.
The battery plays an important role in photovoltaic power system. Hence, the paper illustrates the modeling of one cell of a lead acid battery. The cell model is built up for discharging and charging processes. The two models are a function of the state of charge of the cell during charging and discharging conditions. These models give the cell voltage at any desired value of state of charge and hence against the operating time. The cell model can be extended for obtaining the whole battery model depending upon the number of battery cells. The battery models are very important for determining the battery electrical performance. For obtaining the battery performance experimentally, this needs a very large period of time for the experiments need. The models exhibit a good fitting with the battery experimental performance.
The inverter model gives the relationship between its output and input. The inverter output is time dependence. Conversely its input is independent of time. The inverter model depends upon the pulse width modulation used. The pulse width modulation can be obtained by using rather triangular carrier or ramp carrier wave. The technique of pulse width modulation is used for improving the inverter output waveform and for reducing the harmonic contents. The importance of inverter model is for giving good strategy of pulse signals used for triggering the inverter switches. The model exhibits good conforms between the theoretical pulse strategy and the experimental strategy obtained by the inverter triggering circuit constructed in the laboratory.