Study on control strategy for solar tracking system using variable tracking frequency

A new control strategy for concentration photovoltaic tracking system using variable tracking frequency was proposed in this article. In this strategy, the solar trajectory was discretized by sampling time and the threshold interval was built by using the incident threshold angle of photovoltaic panel. By setting the error of angle between the incidence light and the normal of photovoltaic panel surface as the controlled variable, the strategy uses the lookup table and iterative method to keep dynamic changes of the variable within the threshold interval, so that the solar tracking system can effectively track the solar position by using variable frequency. According to simulation results, the strategy performs better than the constant speed tracking strategy and fixed-step tracking strategy in the tracking accuracy, and keeps the PV modules output ratio above set value. Our proposal is also better than the traditional real-time tracking strategy in the tracking consumption. The system energy consumption and mechanical wear effectively can be reduced. © 2019, Editorial Board of Acta Energiae Solaris Sinica. All right reserved.