Module Maximum Power Modelling

Nominal Power Modelling Discrepancy

\(P_{\text{mod,nom,ref}}\) will typically differ from the module maximum power obtained from the module performance model when the module power is queried supplying the chosen reference conditions as inputs. Denoting modelled module power (as opposed to nominal or "datasheet" module power) under reference conditions as \(P_{\text{mod,mpm,ref}}\) we calculate the Nominal Power Modelling Discrepancy for a specific module type as:

$$\Delta_{npmd,mtype} = \left( \frac{P_{\text{mod},\text{mpm},\text{ref}}}{P_{\text{mod},\text{nom},\text{ref}}} - 1 \right) \bullet 100%$$

Where a plant array is composed of more than one type of module, the Plant Array nominal power modelling discrepancy values are automatically calculated using an average of the values for the composite module types, weighted by capacity using total nominal MPP installed.

The Plant Array nominal power modelling discrepancy is reported in the Effects Diagram immediately below Plant Array Nominal Energy.

Nominal Power Modelling Correction

The user can enter Nominal Power Modelling Correction to compensate for any nominal power modelling discrepancy, as it is often desirable to base the calculation around nominal (datasheet) maximum power. We denote the Nominal Module Performance Correction for a particular module type \(D_{\text{npmc,mtype}}\) This value is a percentage; where no correction is desired, this will equal zero; a positive value indicates that the module performance model maximum power point is considered too low and a positive correction is to be applied to the results it yields (a negative value indicates the opposite).

Where the module performance model is used to obtain voltage and current for a specific module or submodule, then \(D_{\text{npmc,mtype}}\) is to be applied to the current (\(I\)) value.

Where a plant array is composed of more than one type of module, the Plant Array Nominal Power Modelling Correction is calculated using a weighted average of the values for the composite module types, with capacity (using total nominal MPP installed) as the weighting factor.

The Plant Array Nominal Power Modelling Correction is reported in the Effects Diagram immediately below Plant Array nominal power modelling discrepancy (see example above).

The power output of a submodule at maximum power point after the Module Performance Correction has been applied is denoted \(P_{\text{submod,npmc}}\):

$$P_{submod,npmc} = \left( 1 + \frac{\Delta_{npmc,mtype}}{100%} \right) \bullet P_{submod,mpp}$$

To consider the Power Binning Effect alongside other conversion effects in the mismatch calculation, an adjustment to the current from each submodule is calculated as:

$$\eta_{submod,npmc} = \left( 1 + \frac{\Delta_{npmc,mtype}}{100%} \right)$$