Mismatch losses in PV power plants

• The electrical mismatch loss of two different PV arrays have been evaluated.
• Two methods have been applied to calculate the mismatch losses.
• Static and dynamic simulation with real meteorological data have been made.
• The electrical mismatch is small compared to the ohmic and inverters losses.

In this paper, two different PV arrays have been simulated in order to quantify the electrical mismatch loss in each one of them. The simulations have been performed both in the standard condition (STC) and in the dynamic conditions which implement the meteorological data from the two different locations. Two methods have been applied to calculate the mismatch losses. The first one (the simplified method) assumes that all modules are at the tolerance limit and the second one (the I–V curve method) calculates the loss instead from the I–V   characteristic of the modules or of the module series/parallel. Also an ordering procedure starting from the ImpImp value of the module has been evaluated. The results show a very small mismatch loss in the small PV plant of 40 modules, furthermore the ordering does not influence so much the loss in this case. Instead, the loss in the larger array of 320 modules is bigger and the ordering method presents a more significant influence.