Linear and nonlinear light sensors in SCC based maximum power point search algorithms

Photovoltaic panels have nonlinear characteristics. Therefore, there is only one point where the output power from photovoltaic panel at its maximum. This point is called the maximum power point (MPP). There are many of the maximum power point search algorithms in literature. The simplest methods are the open circuit voltage (OCV), the short circuit current (SCC), the perturb and observe method or the incremental conductance method. The most complicated methods use neutral networks or genetic algorithms. The maximum power point current depends on the short circuit current. However, to measure the short circuit current, the photovoltaic panel must be disconnected from the load. Some of methods use an additional module that represents the whole solar panel. The short circuit current depends on the solar irradiation mainly. Therefore, by the measurement of the irradiation the maximum power point current can be estimated. In this work the hybrid method that uses the solar irradiation measurement to determine the initial operating point and then the perturb and observe algorithm for the final seeking is used. The smaller initial seeking error, the smaller perturbation step of the perturb and observe method can be used and the seeking time is shorter. Therefore, in the testing algorithm the solar sensor is the critical element. In this article the linear and nonlinear light sensors in the short circuit current are tested. The integrated sensors like linear BH1603FVC, OPT3001IDNPRQ1, VEML6030 or nonlinear ISL29009 through phototransisors like TEPT4400, photodiode like BPW21 or photoresistor like GL5516 are compared.