Needed Database Entries

The Electric module requires specific device records in the database, such as grids, cables, transformers, inverters, and combiner boxes. With the exception of grids, these devices can also be created while creating a layout; however, it is recommended to create the records in the component management of the Helios database application.

In the final step of this section, we explain how to create a grid record. Since a grid is not a physical device but rather an abstract one, it must be created in the choice list module.

The procedure for creating devices is the same as for any other component in the component management. Therefore, this section focuses on the data specific to each component type.

In the first version of the Electric module, most of the input fields for electrical devices are not yet used in calculations. However, we recommend entering as much information as possible to avoid the need to update all records whenever the program’s functionality changes.

All inputs that are essential for the device to function will be marked with a red frame. An example of this is the input for the count of any electrical device, as transformers, inverters, or combiner boxes cannot be used without this value.

Other values, such as the conductor material and resistivity of a cable, are optional. If these values are missing, the cable can still be used to calculate the total cable required. However, the loss calculation will not be accurate without these inputs, which is why they are marked with an orange frame.

Values that are optional but contribute to a more accurate yield assessment calculation are marked with a sky-blue frame.

Transformer

Transformers are automatically inserted into device areas based on the assignments in the layout.

The input for count and rated voltage is required to use the transformer. The efficiency value reduces the power on the output cable before the cable loss calculation begins. All other entries are optional.

Nominal Voltage [V]

Insert the nominal input voltage (low-voltage side).

Nominal Current [A]

Insert the nominal input current (low-voltage side).

Input Count (required)

Insert the number of inputs.

Power Rating [VA]

Insert the rated power at 25°C (medium-voltage side).

Nominal Power [VA]

Insert the nominal output power at 40°C (medium-voltage side).

Rated Voltage [V] (required)

Insert the rated grid voltage (medium-voltage side).

Nominal Voltage min/max [V]

Insert the nominal AC voltage range (medium-voltage side).

Nominal Current [A]

Insert the nominal output current (medium-voltage side).

Rated Power Frequency [Hz]

Insert the rated power frequency (medium-voltage side).

Efficiency [%]

The efficiency of the device reduces the power delivered to the output cable and decreases the losses in the cable due to its characteristics and length. A value of 0.00% is interpreted as 100%, meaning there is no internal loss.

Inverter

For inverters, most of the input values displayed below are not yet used in Helios 3D. Currently, only the input count is considered. The following values are required:

• Input Count
• Maximum Voltage (Udc MPP)
• Nominal Voltage (Vac nom)
• Euro Efficiency

The other values, marked in bold, will improve the results of the internal yield assessment.

MPPTs can be added to the list below the input fields.

Input Values Voltage (DC-PV-Field)

Max. Voltage (Voltage Cut, Udc MPP max) [V] (required)

Insert the maximum MPP voltage (Voltage Cut). If the voltage exceeds this value, the inverter is disabled for safety reasons (see the following Figure at Voltage Cut min).
This value is considered for the yield assessment if set.

PV Voltage (Voltage Limit, Udc max) [V] (optional)

Insert the maximum PV voltage (Voltage Limit). If the voltage exceeds the Voltage Limit but not the Voltage Cut, the voltage will be reduced to the Limit value (see the previous Figure at Voltage Cut min).
This value is considered for yield assessment if set.

Min. Voltage [V] (required)

Insert the minimum voltage at rated power. Below this value, the device will not be active, meaning strings cannot be connected if the STC string voltage is too low.

Input Count (required)

Insert the number of inputs. Helios uses this value to calculate the number of inverters required. Each input can connect a single module string (for string inverters) or a combiner box (for central inverters). Depending on the placement settings, the device will be inserted behind the last string assigned to it.

Power values

Max. Power (Power Cut) [kW] (required)

Insert the maximum power (Power Cut). If this limit is exceeded, the inverter will be disabled for safety reasons (see the following Figure 165 at Power Cut min).
This value is considered for yield assessment if set.

Power (Power Limit) [kW] (optional)

Insert the maximum PV power (Power Limit). If the Power Limit is exceeded but not the Power Cut, the power will be reduced to the Limit value (see the previous Figure at Power Cut min).
This value is considered for the calculation of cable losses and additionally for yield assessment if set.

Min. Power (Power Cut) [kW] (optional)

Insert the minimum power (Power Cut). Below this value, the inverter will not be active.
This value is considered for yield assessment if set.

Output Values (AC-Grid)

Frequencies (Fac) (not used)

Select the possible frequencies.

Nominal Voltage (Uac nom) [V] (required)

Insert the nominal voltage for the inverter output. This value is used in the calculation of cable losses.

Nominal Current (Iac nom) [kW] (not used)

Insert the nominal current for the inverter output.

Max. Current (Iac max) [kW] (not used)

Insert the maximum current for the inverter output.

Efficiency

Max. Efficiency [%] (not used)

Insert the maximum efficiency of the inverter.

European Efficiency [%] (required)

Insert the European efficiency of the inverter. This value is mandatory for the yield assessment!

Combiner Box

For inverters, most input values are still not used in Helios 3D. Currently, only the input count is considered. The required inputs are the input count and the absolute maximum PV voltage (Vdc max).

Input Values

Input Count (required)

Insert the number of inputs. Helios uses this value to calculate the number of combiner boxes needed. Depending on the placement settings, the device will be inserted behind the last string assigned to it.

Max. Input Current per String [A] (not used)

Insert the maximum input current per string.

Abs. Max. PV-Voltage (Udc max) [V] (required)

Insert the maximum PV voltage. If this value is set, it will be checked when creating a new string definition.

Max. PV-Current (Idc max) [A] (not used)

Insert the maximum PV current.

Max. Wire Cross Section (not used)

Insert the maximum wire cross section.

Type

Current Type (not used)

Select the current type. A combiner box can be used for either the AC or DC side.

Output Values

Max. Wire Cross Section (not used)

Insert the maximum wire cross section.

Ambient Conditions

Temperature Min. / Max. [C°] (not used)

Insert the minimum and maximum ambient temperature.

Cable

Cables are essential for electrical design and for calculating the total cable lengths per article for material lists. Additionally, losses based on the input power and the length of the cable are calculated.

For AC losses, the impedance value is used when available. In the DC part or if no impedance value is provided, the resistance in Ω/km is used. If the resistance is missing, the conductor material (its resistivity value) and cross-section are used instead. The values in Ω/km have been added starting with program version 2024.

Resistance (Ω/km)

This value is used for calculating power losses due to the cable length in the DC part or in the absence of an impedance value.

Impedance (Ω/km)

This value is used for calculating power losses due to the cable length in the AC part.

Conductor Material (required)

Select the conductor material from the choice lists. The resistivity value of the material is defined there.

Resistivity (Ω * mm²/m) (required)

This shows the resistivity value defined for the conductor material, which is set in the choice lists.

Conductor Cross Section Area (required)

Insert the conductor cross-sectional area. This value is necessary for calculating power losses caused by cable lengths.

Grid

Grids can only be created in the choice list module

of the Helios 3D database application.

In the folder structure, select the entry „Electrical Grid“ as shown in the figure below.

In the list to the right of the folder structure, you can create or edit entries using the „Edit“ buttons or the context menu.

The following figure shows the creation dialog. At this stage, the values for voltage and the number of phases are not yet considered.

A good example entry might be:

• Short: 1000/3
• Description: 1000 V, 3 Phases
• Voltage: 1000
• Phases: 3