As shown in Figures 11 (A) and (B), users can add a Solar PV String either directly to a Solar PV Inverter or via a Junction Box component, which serves as a connection point for MPPT inputs or a DC Combiner Box. ElectricalOM features a dedicated input section in the Circuit Edit Module, allowing users to define the electrical characteristics of each string. This enables accurate sizing, performance evaluation, and compliance checks.


A screenshot of a computer??AI-generated content may be incorrect.

Figure 86 PV String Electrical Configuration in the Circuit Edit Module


  1. Number of Modules in the String – Specifies the number of PV modules connected in series within the string.
  2. Module Rated Power (Wp) – Indicates the nominal power output of each PV module under Standard Test Conditions (STC).
  3. Isc_STC (A) – Short-circuit current per module at STC, used for overcurrent protection checks.
  4. Imp_STC (A) – Operating current at maximum power under STC, used to determine the string’s output.
  5. I_MOD_MAX_OCPR (A) – Maximum allowable overcurrent protection rating for each module, based on standards or manufacturer data.
  6. Voc_STC (V) – Open-circuit voltage per module at STC, used for total string voltage calculations.
  7. Vmp_STC (V) – Voltage at the maximum power point under STC, relevant to string operating voltage.
  8. Voc_MAX (V) – Maximum calculated open-circuit voltage under worst-case environmental conditions, used for inverter input checks.
  9. Total String Power (Tot. kW) – Displays the total power output of the string based on the number of modules and their Wp.
  10. Voltage Drop at Design Voltage – Displays the voltage drop across the string at a specified voltage (e.g., 750 V), facilitating verification of compliance with design limits.


Info Icon (ℹ️) 

I_MOD_MAX_OCPR (A) (Point 5)

A screenshot of a computer error??AI-generated content may be incorrect.

Figure 17 Info Icon – PV Module Maximum Overcurrent Protection Rating as per IEC 61730-2