Single-axis tracker PV layout creation

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Single-axis tracker- PV layout creation

Prior to starting with frame creation, it is necessary to set up the Layout generation settings. This can be done by clicking on the Layout generation settings button and adjusting the information that is present there.

In the Layout and generation settings menu it is possible to proceed with the following selections:

• Select Distance units (millimeters/meters or inches/feet).

• Select Slope units (degrees, percentages).

• Select the Restriction zone layer (boundaries on this layer will be avoided by frames).

• The Optimized frames option hides unnecessary objects (3D modules, poles) to increase the performance of AutoCAD.

• The Topographic layout option allows generating on a terrain survey, or on a flat surface when you don't have terrain data.

• Using the Select button you can select or reselect the terrain data to be used.

• Change from Existing (original) topography to Proposed topography (after performing the grading).

The next necessary step before area generation is to set up the Frame & park settings. This can be done by clicking on the Frame & park settings button and adjusting the information that is present in the three tabs there. 

This includes the physical parameters of your frames, placement setup, park's settings, and reference height setup.

Frame creation

Using the Current preset field and adjacent icons, you can:

• Use custom names for frame presets;

• Duplicate the current frame preset;

• Import and export preset configuration:

  

  For more information about importing and exporting settings: Import and export settings

   

• Copy a selected frame’s information;

• Delete an existing preset;

The Module Parameters section allows you to define custom module parameters to match those that are provided by your module manufacturer of choice.

The Frame parameters section allows us to specify:

• The framing type (fixed-tilt, single-axis tracker, or east-west); In our example, we will use a Single-axis tracker.

Here we can also select the subtypes Multi-row trackers and Terrain following trackers and access the corresponding settings:
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Check the following articles for more details on these:
​Multi-row trackers
​Terrain following trackers
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• The module orientation - either portrait or landscape.

• The grid size of the frame - we can specify the number of rows and columns in our frame.

  

• You may also choose to modify the horizontal and vertical gaps between modules.

  

   

• The motor gap allows us to adjust the size of the gap for the motor. You may also opt to not use one by disabling the checkbox.

• The number of joint gaps and their size can be configured as needed.

• In the field Table length, we can see the full length of our frame

   

  

   

• The frame power is determined by the power of the individual modules, multiplied by the number of modules per frame.

We then go to the Custom Piling menu to adjust the piling information for this specific frame.

We are provided with the option to adjust the motor position based on the application. This is referenced in the drawing on the right-hand side of the window.

In the Pole setup window, we can specify the Overhang for the far ends of our frames.

We can also adjust the Pole amount. We are also free to adjust the distances between the poles as we see fit. This is referenced in the drawing on the right-hand side of the window.

Just below, we have the option to toggle on equal margins - this will make it so that the distance from the ends of the frame to the closest pole is the same.

Also, we are able to toggle on Mirror from the middle - using this, the software will mirror the values we input in the first half of the spacing table and the second half will be auto-populated to match.

Under Torque tube setup, we can define

• the turning angle range and if desired

• torque tube diameter

• top gap, from back of the frame

• bottom gap, from head of the pile

   

  

With the torque tube configuration, it is possible to represent in more detail trackers that use concentric bearings, which have the widest market adoption so far.
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Once satisfied with the piling options, we click Okay to finalize the process.

Placement setup

Having explored the Frame Creation capabilities of PVcase, we can now explore the placement setup options. Firstly, we open the Placement Setup menu tab and select Single-axis trackers.

Here we see the Preset Library field which contains all the presets we created just before for this specific DWG file. From here you can select which of the available presets we should use when creating new PV areas. You can select one or multiple presets that you would like to utilize, as long as they have matching row counts, vertical gap size, and tilt angles.

As with our example, we can see that we are not able to select one of the presets as it has 2 rows rather than 1.

There is also an option to choose a specific color for each preset. To do so, just click on a color box, choose the specific color and press okay to finalize.

Just below the Preset Library field, we can see the option to select the frame placement order.

For Single-axis trackers, there is only one option available - Descending from the alignment line denotes that when populating the PV area, the software will put larger frames closest to the alignment line and will keep the smaller frames on the opposite side.

Park settings

Having created and selected our frame presets, we will now proceed to the Park settings options.

We can see that the two main sections are Inter-row settings and Corridor settings.

The inter-row settings allow you to define the Pitch, Inner spacing (East-West displacement of frames), and Row spacing (North-South displacement of frames).

If we change the Pitch value to 10m, the inner spacing will automatically be calculated. Changing the inner spacing will consequently affect the pitch value - they are directly linked.

Additionally, Alignment type is an important feature, which allows us to specify how the frames will be organized.

Line will better utilize the available PV area to achieve as much capacity as possible, at the cost of alignment and orderly design. It may be advantageous to do so in smaller PV areas.

Grid and Motor will follow an orderly grid pattern, which we can control in the Corridor settings.

Grid uses the top of the frame as the reference point while in Motor, motor gap are used as the main alignment reference.

Note: please note that for Motor to work as intended, the number of modules on either side of the motor should be matching as well as the size of the motor gaps or joint gaps between the presets.

We are also able to set or draw azimuth for the trackers - up to 89.9°.

Corridor settings, if enabled, allow us to space our frames in the PV area in a more efficient, orderly fashion, allowing us to account for maintenance road clearances as well as splitting the PV areas into a grid. You can also control the size of every second gap independently of the main vertical corridor gap, which gives more flexibility.

Once we enable the Tracker corridors, we can edit the parameters, which will be illustrated and updated on the right-hand side of the window. Finally, we may also enable Corridor lines - these may be converted to roads if needed.

Note that it usually makes sense to use Grid or Motor when creating Corridors.

Height & Optimization

The Height & Optimization settings section allows us to define the reference frame height for the PV area we intend to generate.

When we open the tab, we will see there are two layout generation modes:

• Standard: this option will use the Frame reveal value on the edges of the axis line of the table, considering overhangs if they exist.

• Optimized: this option will open up a range for which the reference height can vary. This option will prioritize placing frames to the lowest reference height, but if any collision is detected, the frame will be lifted to avoid collisions, up to the maximum range value.

  

For more information about the optimized generation mode, visit Layout generation: optimized mode

Additionally, layouts where tracking systems are used can have the torque tube enabled or disabled, and the values displayed for each scenario are different.

• Without torque tube enabled:(Pile and Frame reveal are considered to be equal)

• With torque tube enabled:

In the following image, an illustration of what the Pile and frame reveal is displayed. 

(Pole reveal + Torque tube diameter + Top gap + Bottom gap = Frame reveal)

Please note that this is a reference, not a minimum height. The input field is for the lowest frame height on a flat terrain rather than the minimum clearance height. PVcase places frames based on the frame reveal height, without taking mid-frame terrain collision into account. However, terrain collision can be analyzed at a later stage, as part of our Civil analysis section.

To read more about Civil analysis click on the button below:

Area generation

The first step in generating areas is to define the PV area in which we will be working. A PV area in PVcase should be defined by a closed polyline. This can be done by using the default AutoCAD polyline function. This can be summoned by typing PLINE, pressing Enter and drawing the desired perimeter of the PV area, ensuring that the polyline is finished at the starting point. This will yield a closed polyline, suitable for PV area population.

Once the Frame & Park Settings are configured to your specifications and we have a suitable PV area perimeter polyline, we can generate the PV areas in one of these ways - either one at a time or multiple PV areas simultaneously.

First, let us showcase the creation of singular PV areas. While the single area option is the default, you can select whether you want to generate a single area or multiple areas by clicking on the drop-down menu and choosing Generate single area.

Having chosen this option, we are prompted to select our PV area boundary - select our newly-drawn polyline and press Space or ENTER on the keyboard. You will then be prompted to define an Alignment line.

An alignment line is used to indicate the alignment bias of PV frames when creating PV areas. We can draw alignment lines on the PV area perimeter polyline as well as inside of it and outside of it. In our example, we will draw the Alignment line in the middle of our PV area - once we have our line, we press Enter or Space on the keyboard - this will initiate the generation of our frames in the PV area. Depending on the size of the area, this should only take a few seconds - you will then be able to see our newly-generated frames in the PV area we defined.

For our next example, let us clear the PV area by right-clicking on the PV area perimeter line, going to the PVcase sub-menu, and clicking on the Clear PV area option.

Then, for illustration purposes, we can generate frames for the remaining PV areas with the Generate multiple areas button. By clicking on the dropdown menu, we select the Generate multiple areas option, which prompts us to select our PV areas. Once all areas are selected, press Space or Enter on the keyboard and draw the alignment line for both areas - when generating multiple areas simultaneously, you are restricted to having a singular alignment line for both. Once we have the alignment line, press Space or Enter on the keyboard and we will have all PV areas populated shortly.

Generate multiple areas - this generation should be used when multiple areas are next to each other and need to have rows aligned between them.

Generate with Capacity iteration - This mode allows to calculate different scenarios based on varying row spacing and tilt angle.
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Learn more in Capacity iteration

Row alignment

PVcase has the option to enforce row alignment, meaning that PVcase will make an effort to keep the same layout as much as possible. The software will opt to keep the uniformity of the layout, choosing not to populate areas with objects in the PVcase Offsets layer (for example, trees/buildings) or if the PV area is non-rectangular, it may opt not to populate certain regions of the area. With alignment type Grid or Motor, rows are aligned, but there are empty areas because of restriction zones and keeping the alignment:

Meanwhile, alignment type Line will make a greater effort to populate the entire PV area more densely at the cost of uniformity, especially when having to respect the PVcase Offsets layer restrictions. In the example below, the area is filled up better, especially around the restriction zone, however, the rows are misaligned which might not be ideal:
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Show piling

Once the PV areas are generated, we can proceed to generate our piling. This can be done by clicking the Show piling button, selecting the PV area perimeter line, and pressing Space or Enter on the keyboard. Soon enough, your frames will be populated with their poles.

To see what the piling looks like, we may choose an isometric view (SW Isometric, for example) and/or while holding the Shift key and Middle Mouse button to rotate the view manually using the mouse.

Pile grouping by length

This function allows us to see how many piles belong to each length group and how they're spatially distributed, allowing us to spot problematic areas in need of changes to either pole lengths or grading.

• Run Show piling as described above

• Open the Pile grouping window from the same drop-down menu:

  

   

• Define the start and end values of the length groups and the increments between each and customize group colors:

   

  

   

• Select PVarea(s) and run Group piles - this will color each pile according to its length group and populate the pile count in the table:

  

   

   

• Export to CAD model space and/or to the BOM Excel sheet

  

Frame grouping with power station placement

Frame grouping allows you to quickly and easily group PV frames and place a power station to serve them. You can quickly "block out" a PV area for the initial phase of the design. There's no need to add any electrical devices (strings, combiners, inverters) at this stage. It's just to get an idea of where to place the power stations. This is useful at the preliminary design stage, where there is no time to do a full electrical design, but you need to give an idea of the power station locations for project stakeholders or authorities.

On the ribbon, select "Frame grouping" and a window will open.

First, you can decide whether your Frame groups will contain power stations or not.

If enabled, you can set up the details of the power station. It can be modelled in two ways:

• You can select an existing AutoCAD block object.

• Alternatively, you can define the dimensions of the unit, and a block will be created for you.

The AC Power is used to determine DC/AC ratio when selecting the PV frames that will be assigned to the power station. The offset setting will displace any frames with the defined offset area. You can also choose the coloors that your frame groups will be created with.

When you want to start grouping the frames, hit "Group."

First, select your PV frames, until you are happy with the DC/AC ratio and press Enter.

Then, if enabled, you can choose the position of your power station. Wherever you place it, PV frames will be automatically removed from the offset area that you have chosen.

If you choose not to place power stations, you will be prompted to pick frames for the next area. You can keep adding frame groups and power stations until you are done. The colors for the areas will be chosen according to your settings.

The grouping will also be displayed in the Electrical devices overview if you have enabled powerstation placement:​
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