Small-Signal Stability Analysis With Approximated PV Model for Solar Array Simulator

Solar array simulators (SAS) equipment is used to mimic the characteristics curve for photovoltaic (PV) generators. However, an in-depth stability analysis of the SAS with respect to its reference signal is yet to be investigated. This is due to implicit and nonlinear mapping equations used to describe the <inline-formula><tex-math notation="LaTeX">$I\text{--}V$</tex-math></inline-formula> curve, which complicates the loop analysis. Our study proposes a super-elliptical method to approximate the <inline-formula><tex-math notation="LaTeX">$I\text{--}V$</tex-math></inline-formula> characteristic curve and provide an explicit PV equation that is straightforward to manipulate. Furthermore, this approximate model is then used for the dynamic performance assessment for the typical control architecture. Based on the comparative study using the approximate mode either in the theoretical analysis and the experimental verification, the resistance-sensing control scheme tends to reduce the effect of loop interactions in the SAS, thereby showing more consistent dynamic performance than the other control structure.