Medium Voltage Cable

5.5 Medium Voltage Cable

This function is mainly used to complete the electrical connection from the transformer box to the grid connection point. After completing this function, the length of the medium voltage cable can be counted, and the medium voltage connection diagram and medium voltage cable path diagram can be drawn.

5.5.1 Flow sheet

The flow sheet is shown in the following figure:

5.5.2 Put/Edit connection Points

Select the type and place it. Put a connection point for each circuit.

After clicking the "Edit device" button, you can perform operations such as moving and deleting the selected grid point through the right-click menu. You can select the device by clicking on it or the upper left legend.

5.5.3 Put/Edit middle points

Middle points may a MV connection box or towers.

1. If there is an overhead line, place a tower type midpoint in the overhead section in advance.

2. Drawing cable paths and pass through them.

3. Check the cable.

Attention: The overhead line requires at least 2 or more of towers.

Insert or pre-place the midpoint of the tower	Actual connection effect

After clicking the "Edit Middle Point" button, you can perform operations such as moving and deleting the selected point through the right-click menu. You can select the midpoint by clicking on the midpoint entity or the upper left legend.

5.5.4 Draw and Edit Paths

5.5.4.1 Draw Medium Voltage Paths

Starting from the center of the medium voltage grid connection point, it can be drawn in a tree like or circular structure, or a mixture of both. The path only needs to pass near the transformer (when the distance from the center of the transformer to the path is less than the "Max distance from trans.to MV trench", it can be connected to the path. The default value is 10 meters, which can be modified by viewing MV cable -- right-click menu or user settings).

When drawing a medium voltage path, attention should be paid to:

1) Multiple grid connection points can share a common path.

2) When a transformer has 2 or more paths passing through and the distance is less than the "Max distance from trans.to MV trench", the software will prioritize the closest path.

Enter the "Draw Path" tool and right-click to switch to the edit cable path mode, where you can delete paths and move the points of paths. To delete all paths, you can click on "Clear Paths" on the interface.

After completing the path drawing, you can right-click on "Show Connected Path Groups". The software will group the interconnected paths together and render them in different colors. This tool can be used to check whether the drawn paths are connected to the grid connection point.

5.5.4.1 Importing Medium Voltage Paths from Layers

Firstly, process the medium voltage cable path in CAD, requiring the path to start from the center of the grid connection point and be continuous and uninterrupted, with a polyline thickness and width of 0.

Click the "Draw Path" button on the above interface, press F2 to select the layer and complete the import.

When the distance between the end of the imported path and the start point is less than 5 meters, the start point will be automatically connected and the line segment from the end to the start point will be added. When it exceeds 5 meters, it is necessary to add the path manually.

5.5.5 Wiring

After clicking on "Manual wiring", select the power block and right-click to add it to the designated grid connection points. The results will be displayed in different colors.

Wiring process - select block 4 # and 8 # that have not wired yet
Wiring result - Block 4 # and 8 # are added into 1 # grid connection point

After selecting the power block or midpoint, right-click to bring up the menu where you can "Create MV Point", "Add to MV Point", etc..

Similarly, user can select the devices in the upper left corner legend and right clicking on the menu.

5.5.6 Medium voltage auto combine

1) Preparatory steps

Switch to "Normal Type";

② Put Start point (at least one), and place Middle Tower (if any);

③ Draw the path between the Start point, Transformer, and Middle Tower (refer to Section 5.5.4 for reference);

④ Manually combine the blocks and the middle towers to be auto created into a grid connection point;

After completing the above steps, click on "AUTO wiring" and select a Divided start point from the pop-up box.

2) Relevant parameter settings

Settings for "Parameter settings" and "Optimization target" need to be made.

① Parameter settings:

Setting the capacity of each circuit, two options are available: "Select by QTY. of Transf." and "Select by Capacity per Circuit".

"General/Maximum Allowable Cable Length between Transformers": This refers to the generally reasonable length and the upper limit of the cable length between transformers (it is recommended to Click on the recommended value).

② Optimization Objective:

Two optimization orientations are provided: "Based on the shortest cable route" and "Based on the lowest cable CPEX". When selecting "Based on the lowest cable CPEX", if you need to adjust the cable model, you can click "Cable settings" to reset the relevant parameters in the cable list.

3) Auto Combine

After completing the above parameter settings, click the "Calculate" button, and the software will display the AUTO wiring plan in the List of results.

Click the "Preview" button, and users can view the details of the current scheme.

Select the appropriate result based on the "Result combination" and "Total Cost/Total Length" displayed on the interface, and click the "Apply" button.

Note: If no results or the result does not meet the requirements, you can modify the relevant parameters and re-calculate. For details, see the "Usage Tips" on the Medium voltage Auto Combine interface.

5.5.7 Ring topology

This feature is a High-reliability Medium voltage topology solution provided by the software for medium to large-scale photovoltaic power stations.

1) Before initiating the Medium voltage ring network configuration, the following steps must be completed:

① Switch to "Ring Mode"

② Put Start point, and place MV connection box (if any);

③ Draw the path between the Start point, Transformer, and the intermediate connection box (refer to Section 5.5.4).

2) After completing the above steps, click on "Grid Point Pairing". Select two grid points to complete the pairing. The right-click menu allows you to clear "All/Current Grid Point Pairings" and delete "Medium Voltage Grid Points or all unpaired Grid Points".

3) Manual Combine

Click "Manual string", select the power block, and right-click to add it to the specified code of the Medium voltage Start point. The results will be displayed in different colors, with each color representing the electrical connection results of a different Medium voltage Start point (refer to Section 5.5.5).