Simulation

Last modified: 2026-08-20

About the simulation

The simulation in VCOM provides a real-time target value of expected power/energy for each of your PV systems. Both the sensor-based and satellite-based simulations are based on the interval defined for your system (e.g. 5/10/15 min).

The simulation affects the following areas of VCOM:

• Expected power (simulation) chart

• Expected energy (simulation) – level comparison chart

• Loss breakdown chart

• Expected AC energy range (simulation) chart in the section Inverters.

• Control visualization chart

• Current system status portlet

• Total outage alarms and Misproduction alarms: Separate configuration required. See Calculation methods for total outage and misproduction alarms.

Simulation parameters

Target range

The Target range defines the acceptable deviation from the simulated expected power or energy. The target value itself is a single, exact value generated by the simulation. You specify the target range as a percentage of that value, and it is applied symmetrically as a positive and negative tolerance around the target.

Values that fall below the lower limit of the target range are considered yield losses. Values within the target range are considered acceptable.

Example

1. The exact simulated target value for Expected energy is 100%.
   e.g. 990.95 kWh

2. You specify a general Target range.
   e.g. 10%

3. The acceptable target range is calculated as 100% ± 10%, resulting in a target range of 90% to 110%.
   e.g. 891.85 kWh-1,090.04 kWh

Simulation methods

The following methods are used to estimate theoretical production. The method you choose depends on your system setup and preferences.

Target performance ratio (PR)

This is the default method and is a basic simulation based on the Target performance ratio.

Physical simulation

The physical simulation uses additional parameters to provide more accurate results:

• Sensor irradiance: All irradiance sensors defined in a system are taken into account, depending on how they fit the production. This includes sensors connected to the data logger and sensors defined as a term.

• Number of modules

• Module power: maximum power points in the subsystem setup

• Number of inverters

• Inverter output power: rated output power

• Power control correction value

Machine learning simulation (artificial intelligence optimized simulation)

Machine learning algorithms analyze the historically measured data of the PV system and optimize the physical simulation. The machine learning simulation allows you to learn site-specific characteristics such as shading, clipping, and degradation.

Expand for further details on the machine learning simulation

Prerequisites

• All inverters are assigned to a subsystem

• If using irradiance sensor data: at least one working irradiance sensor. Otherwise, satellite data is used.

• 70% or more of the daytime data points are valid.

• At least two weeks’ worth of valid daytime training data within the last 30 days is available. Valid means, for example, no snow, power control, or outages.

Note

Because this simulation method requires a sufficient amount of training data, it can only be selected for new systems after a certain amount of time has passed: a minimum of 2 weeks and a maximum of 4 weeks.

Comparison of the physical simulation and machine learning simulation

The graphics below show how the physical simulation can be improved with machine learning, using clipping and shading as examples.

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Examples

Clipping

Shading

Configure the simulation

Select the simulation method you want to use to calculate the expected power in the evaluation charts.

1. At System level , go to System settings > Calculations > Simulation.

2. Select a percentage for the Target range.

3. Select the Simulation method.

4. Select Save.

The selected method is now applied to calculations. The expected power/energy is displayed in the charts accordingly.

Recalculate simulation values

If you change a term, for example, an irradiance term, you may need to recalculate the simulation.

1. At System level , go to System settings > Calculations > Simulation.

2. Under Recalculation, select the period you want to recalculate.

3. Select Start recalculation.

The recalculation will appear in the table below, and the recalculated values will be applied to the relevant charts.