Reserve Power Control for Parallel Connected PV Modules under Partial Shading

To enable frequency regulation capability in photovoltaics (PV), the deloading based power control is well known. In this control, the operation of photovoltaics is conducted at a point lower than the maximum power point. Many deloading methods have already been reported for uniform shading conditions, whereas, the field of deloading for partial shading conditions is still less explored. However, these partial shading reserve methods have been designed by considering the usual series connection of different modules. Whereas, some applications may have modules connected in a parallel configuration. So far, for partial shading patterns, there has been no reported method for reserve generation in parallel connected photovoltaic modules. In this paper, a novel reserve method for the modules connected in parallel connection with partial shading patterns is presented. In this method, the power reserve is generated by a parallel modules reserve algorithm. This algorithm operates by continuously sensing the current of each module. Whereas, the reference power for the algorithm is obtained from a proposed droop control. The performance of these controls is validated with the help of simulation (MATLAB software).