A Novel Improved Variable Step Size INC MPPT Method for PV Systems

In order to solve the problem of maximum power point tracking (MPPT) of photovoltaic (PV) array, a MPPT method based on the combination of variable step size incremental conductance (INC) method and short circuit current method is proposed. When the external environment of the PV array suddenly changes, the short circuit current method is used for preliminary tracking. When the working point of the PV array approaches the maximum power point (MPP), in order to avoid large power oscillation, the variable step size increment conductance MPPT method is used for further tracking. The experimental results showed that, the improved method not only can make up for the shortcomings of the short circuit current method in accuracy, but also effectively solves the problem that the variable step size increment conductance MPPT method needs to weigh the power oscillation and response time. Thus, the improved method may enhance the efficiency of the PV system.