Multi-Input Devices

We've recently introduced some added flexibility for micro inverters and optimizers. Previously, the number of modules per device was hard-coded into the device. With our latest release you can now customize the number of modules and their method of connection into the device.

The maximum input voltage, input current, and power rating of the device are used to determine the default number of modules that are automatically connected. HelioScope will automatically determine whether the modules should be connected in series or parallel depending on the voltage and current rating of the components.

Example 1

The SolarEdge P850 has the following specifications:

  • Maximum short circuit current (Isc): 12.5A
  • Maximum input voltage (Voc): 120V

Assuming a module with 40V Voc and 10A Isc, HelioScope will automatically select 2 modules in series for a total voltage of 80V and total amperage of 10A into the device.

Example 2

The SolarEdge P860 has the following specifications:

  • Maximum short circuit current (Isc): 22A
  • Maximum input voltage (Voc): 60V

Assuming the same module specifications, HelioScope will automatically select 2 modules in parallel for a total voltage of 40V and a total amperage of 20A into the device.

A Few Quick Points

  • These same principles will be applied for multi-input micro inverters.
  • Any automatic configuration can be manually overridden by the user
  • Manual configurations can set the number of modules in series and the number of modules in parallel
  • Parallel inputs need to have matching voltage, so HelioScope will automatically set parallel inputs to have identical module counts.
  • Users can now input one module into devices intended for multiple inputs (i.e. putting one large module on a 2:1 device).
  • When a max input is set (automatically or by the user) HelioScope may put less modules on a device to ensure flexible stringing (i.e. a design with 9 modules would have five 2:1 devices and the 5th device would only need one module).

Trackers Beta Improvement

Single-axis trackers are currently in beta and in the course of our testing we have identified an error in our simulator which caused it to report incorrect values for reflected irradiance. Since this is typically the smallest component of total irradiance the issue would result in a discrepancy in specific yield of about one percent or less from the now corrected value.

East-West Racking Bug Fix

We identified a bug for East-West racking designs when the module orientation was set to portrait. The output variance was very small; typically less than +/- 0.5%. The issue was caused by not properly accounting for the bypass diode orientation when the module was changed from landscape to portrait. The latest version of HelioScope now correctly accounts for the fact that bypass diodes trigger proportionally to inter-row shading when modules are in landscape, and all bypass diodes will trigger together when a portion of the module is shaded in portrait.