In this document
We will explain how to configure cable routes in your design and set losses for more accurate cost calculations.
The energy system designer enables you to set % losses for low voltage (LV) DC and AC cables, medium voltage (MV) AC, and high-voltage (HV) AC cables.
For MV AC and HV AC cables, you can decide if you want to use simplified % losses only or define complete cable connection definitions with full parameters such as cable routes, cross-sectional area, cable grouping, material, depth of cable laying, or ground ambient temperature. By setting these parameters, your calculations of losses will be more accurate, and CAPEX (cost) calculations closer to the real cost.
The cabling configuration uses Solargis cable sizing model to calculate the values.
Important: Values shown are not operational results. They are STC-derived inputs used solely for cable dimensioning (ampacity, voltage drop, short-circuit). Actual MV/HV losses are calculated only in the energy simulation.
Prerequisites
Before you begin the cabling setup, ensure you completed the following configuration steps:
Ensure you have editing rights for the given project and access to the Energy system designer.
Define and set up all individual photovoltaic arrays to determine their power output.
Select and configure the specific transformers for your project.
Define the grid connection voltage to determine if an additional power transformer is required.
Ensure that the power output and grid connection parameters are finalized before you proceed to cable dimensioning.
Cabling setup for MV AC and HV AC cables
We recommend following these steps to set up the MV and HV cabling for your project:
Adjust cable routes: Modify the cable paths based on the finalized positions of the inverter transformers, power transformers, and the grid connection point to ensure a realistic layout.
Set cable grouping and sizing: Begin the technical configuration of the cables in the cable configuration table.
Configure the cabling losses: Review and adjust cabling losses as required.
Review the Bill of Materials (BoM): Verify that the accumulated cable lengths appear in the CAPEX, where you can define specific costs for each item.
Note: You can access all cabling settings via the Cabling section of the main menu.
Adjusting cable routes
To adjust cable routes in your design, go to Cabling and click the “Edit routes” button in the Cable routing panel.
Go to Cabling section.
Click the “Edit routes” button to open the cable routing editor.
Click the edit icon of a cable route you want to adjust or click the cable on the 3D scene. The cable route color will change to purple.
Drag and drop the mid-points one by one until you place the cable in the required position. New points will appear as you adjust the path.
You can review the selected cable length and elevation in the editor in real time. Non-adjusted cables show a warning next to the length in the properties panel.
Adjust this way all cables in the design until you achieve the required layout. Use the “Finish” button to finish the cable routing setup.
Tips:
You can reset all cable routes to their default position using the “Reset cable routes” link in the route editor.
When you start adjusting the routes, you will always start with one drag point in the middle. As you adjust it, new drag points will appear in between the endpoints. The more points you drag around, the more points will appear.
Setting up MV and HV cable parameters
To set up cable parameters and sizing, click the “Open cable table”.
The table lists all MV and HV cables, their properties, and their losses. Default values are set in compliance with the International Electrotechnical Commission (IEC) technical standards. Here, you can change default grouping and parallel circuit values, cross section area, modify acceptance criteria setup (max power loss, voltage drop and expected maximum thermal short-circuit current), or other properties such as material, armoring, routing correction factor, and more.
You can change values in fields highlighted in blue.
Green calculated parameters are within the permitted ranges, and red outside of the ranges. Details about the calculated values are explained in the Calculated parameters list dropdown below.
Toggle expert mode to reveal more cable parameters in the table.
Set additional parameters in the right-hand-side panel. Switch between MV and HV panels if required, and scroll down to reveal more settings.
Automatically adjust the cable sizes to meet criteria using the provided button if preferred.
Use the “Apply” button to apply the changes.
Calculated parameters list
ICC criterion (%): The system calculates this value by dividing the derated cable current-carrying capacity by the nominal current and multiplying by 100. A result of higher than 100% indicates that the cable ampacity is sufficient, and the tool displays this in green.
Short-circuit criterion (%): The system determines this percentage by dividing the cable thermal short-circuit withstand by the expected maximum fault current and multiplying by 100. A value higher than 100% confirms the cable can withstand the specified 1-second fault current.
Voltage drop criterion (%): This parameter represents the actual voltage drop along the cable run as a percentage. The result is compliant and appears in green when it remains below the configured maximum voltage drop.
Power loss criterion (%): This figure shows the actual active power loss on the cable run expressed as a percentage. The result is compliant and appears in green when it remains below the configured maximum active power loss.
Adjustable parameters list
Cables in group: You must configure this parameter to account for thermal interference between adjacent cables, as proximity significantly reduces current-carrying capacity. Enter a value representing the total number of three-phase circuits laid side by side in proximity. This must be at least equal to the number of parallel circuits, but if other circuits from different sources are routed in the same location, you must increase this value to ensure the correct thermal reduction factor (K4)is applied.
Parallel circuits: This parameter defines the number of parallel electrical paths used to distribute the load across the system.
Cross section: You can select the cross-sectional area of the conductor to ensure it meets the required current-carrying capacity.
Max active power loss: This setting establishes the maximum allowable energy dissipated as heat within the cabling during operation.
Max voltage drop: You can set the maximum allowable voltage drop for the cable run.
Expected maximum thermal short circuit current for 1 sec. fault: The maximum 1-second fault current the cable can withstand. The system calculates this using the adiabatic method, assuming an initial conductor temperature of 90 °C and a final short-circuit temperature of 250 °C.
Material: You can choose the conductive material, such as copper or aluminum, used for the cable cores.
Armoring: This option allows you to specify the type of mechanical protection wrapped around the cable for durability.
Routing correction factor: You can apply an installation factor (rlcf) expressed in % to adjust the cable length. This accounts for bending radii, wavy laying patterns, and termination allowance.
Depth of laying: This parameter defines how deep you install the cables below the ground surface.
Core numbers: You can specify the number of individual insulated conductors contained within a single cable jacket.
Layout: Specifies the physical arrangement:
Trefoil formation (cables touching in a triangular shape).
Flat formation (cables laid side-by-side with specific clearance). For single-core cables, 3 cables create one three-phase circuit; for three-core cables, 1 cable creates one three-phase circuit.
Circuits centers spacing: You can define the physical distance between the center points of adjacent cable circuits.
Ambient ground temperature: This value represents the surrounding temperature of the soil where you install the cables.
Soil thermal resistivity: This parameter measures the soil's ability to resist the flow of heat generated by the cables.
Setting up cable losses
You can set cable losses directly in the Cabling properties panel. Cabling losses are set in percent:
Set low voltage losses.
Switch to the loss tab and set MV and HV losses.
Verifying cable presence in the Bill of materials
After successful configuration of the cable routes, verify if the cumulative length of all cables appears and is updated in the Bill of Materials (BOM). Once confirmed, you can set prices to include the accurate cabling lengths in the cost calculations.