Before we get started with learning adding string inverter, ensure that the design has been created and modules are also added in the design.
Step 1. Click on the inverter menu(or use shortcut 'i' from keyboard) on left tool menu.
Step 2. Select string inverter from right sap pane based on system capacity.
Step 3. Search the required inverter. In this case we will choose a 15 kilowatt inverter. As soon as we will select inverter, a 2D model of inverter will get added on the mouse pointer. Now, we can place the inverter at the required location.
Step 4. Now to add strings click on the inverter. On the right sap pane go to inverter section and here we have two options that is to add an optimizer or create strings. If we want to add optimizers as well, then you can click on select optimizers option or we can directly go to add string option and create strings.
Step 5. Let's start with adding string. To add string we will click on MPPT(Maximum Power Point tracker) dropdown.
So, we can see we have three MPPT in the selected inverter. It's always recommended that we create strings of similar string length and add it in a single Maximum Power Point tracker. It's always recommended that you create strings on individual facets. If you create strings with different module tilt or azimuth then it will reduce your losses because of the increase in mismatch losses.
It is recommended that if there are any shadow causing objects on or around the roof then also we should attach all the shaded modules in one string and add them in one maximum power point tracker. Or we can do it based on available unshaded modules. First create strings of the modules which are not shaded and then the shaded panels can be added into the other maximum power point tracker.
So in this case we will use all the facets and also if you are using optimizer then you don't need to worry about shading on modules. Because optimizers take care of stringing on different tilt and azimuth as well.
Step 6. Before we start creating strings just make sure to check what is the maximum and minimum number of strings that can be created.
Click on the dropdown icon beside MPPT for which you want to check minimum and maximum string range.
Step 7. To start adding string, click on 'Add string' button.
This will take us to stringing mode. Hover the mouse pointer over modules. This will show the no. of modules getting added in string. There is a minimum and maximum limit to the no. of modules we can connect in one string. Therefore if the strings that you have created is below recommended size or exceed maximum string length then the string color will turn red indicating wrong string sizing.
Let's start creating strings. It is recommended that first add all the strings in a single MPPT, and create strings of the same string length.
When strings lie within supported string range it will show green in color, when it exceeds maximum string range it will appear red.
Step 8. You also have the flexibility that you can add or delete the existing string or make any edits. Clicking on edit will take you to the string edit mode. You can edit the existing string and then click on complete.
Based on the MPPT available, minimum and Maximum string length we have created all the strings.
These strings that we have created:-
In MPPT 1, we have 1 string that we have created, string length is 6(6 modules connected in one string).
In MPPT 2, we have 2 strings that we have created, string length is 8(8 modules connected in each string).
In MPPT 3, we have 2 strings that we have created, string length is 11(11 modules connected in each string).
Also if we zoom in a bit we would be able to see that all the strings are labeled. So the color of MPPT and the color string connected to this MPPT is same.
NOTE: The central inverter and hybrid inverter work similarly to the string inverter. That is the steps to be followed will be the same as that would be for string inverters.