Creating a One-Line Diagram Part I

Creat ing a One-line Diagram The purpose of this tutorial is to show the fundamentals of building and manipulating a one-line diagram in ETAP. Various elements will be added to the one-line view (OLV), and an introduction to composite networks will be made. The figure below displays the one-line which we will create. Final one-line diagram Creating a New Project ÿ Start ETAP Demo and select the option “New Project” for this tutorial. Adding Elements to the One-Live View ÿ To build or edit a one-line diagram in ETAP, you must be in Edit Mode. Click the Edit button on the Mode toolbar. ÿ On the AC Edit toolbar, select a Power Grid (Utility) element by clicking on the Power Grid button. The cursor will change to the Power Grid icon when moving over the OLV. Click anywhere in the OLV to place a Utility on your one-line diagram. ÿ By following the same procedure, insert the following elements until your one-line appears as follows: ☺Helpful Tips… Double-clicking on an element button allows you to drop it more than once. When finished just press the Esc key. ☺Helpful Tips… You can zoom in out , zoom , and zoom to fit page the OLV by clicking on the respective buttons located in the Project Toolbar. ÿ You can stretch buses by placing the mouse pointer over either end of the bus, until a double arrow appears. Then click and drag to the desired length. Connecting Elements ÿ Now connect the elements in the one-line. Place the mouse pointer over the connection pin of an element, and it will turn red. Then click and drag to the connection pin of another element. Follow this procedure to connect all the elements on the one-line. In the case of buses, the entire element graphic functions as a connection point. Notice that a node is automatically inserted when connecting the cable to the transformer. ☺Helpful Tips… You can change the size, orientation and symbol standard for an element by right-clicking on the element and selecting the attribute you would like to change. Node automatically inserted Power Grid U1 1250 MVAsc X/R = 120 Cable1 NEC 5.0kV 3/C CU, 133% Size = 4/0 Length = 200ft Transformer T1 Prim. kV = 4.16kV Sec. kV = 0.48kV 20 MVA %Z = 6 X/R = 17 Motor Mtr1 400 HP ÿ Enter the values for the elements shown in the figure above referring to the Editing Element Properties leaflet. Notice how the voltage of the buses are automatically updated to the value of the primary and secondary kV entered into the transformer properties. Adding Elements into a Network ÿ Populating a composite network is very similar to populating the first one-line. To open the composite network, double-click it’s graphic. The title of this window will be OLV1=>Network1. You may change its name by double-clicking anywhere inside the network’s OLV or by right-clicking on its graphic and selecting Properties. Connect the elements shown below to create a one-line diagram as was done previously. Now, to make this one-line look cleaner, you can right-click and select Hide Unconnected Pins. ☺Helpful Tips… Using composite networks helps making large one-line diagrams manageable. Cable2 NEC 5.0kV 3/C CU, 133% Size = 4/0 Length = 100ft Lump1 MVA = 5 %PF = 80 Motor Mtr2 150 HP Adding a Protective Device (PD) to your One-Line ÿ Ensure that there is enough room between the elements you wish to add a PD. Adding a PD to your one-line does not require you to delete the line connecting the elements, instead, insert the PD on to the line where you like it to be. The PD will automatically connect to the line. Follow this procedure to add the remaining PDs shown in the final one-line. ÿ To check if an element is energized click on the continuity icon located in the project toolbar. All elements that are not energized will be grayed out. For example, with the continuity check on, open CB4. As shown in the figure to the right, CB4 and elements downstream are grayed out ÿ Creating a one-line diagram in ETAP is fast and easy. Once complete, you can take full advantage of all the powerful tools that ETAP has to offer. Edit ing Elem ent Propert ies The purpose of this tutorial is to show the fundamentals of editing the properties of four elements: Motor, Cable, Transformer, and Lumped Load. For this tutorial you should select “Example Project (ANSI)” option when starting ETAP Demo. Motor Properties ÿ Open the editor for Mtr2 by double-clicking on the element or right-clicking on the element and selecting Properties. Doing so will open the property editor for Mtr2 as shown below. ☺Helpful Tips… You can navigate to other motor editors by using the navigation tools provided at the bottom of the editor. ÿ When the editor opens, you are taken to the Info page. In this page you can place the motor in service or out of service, edit the ID of the motor (must be unique), change the bus it is connected to, and enter the equipment information. You can also specify the connection type and quantity of motors under the connection section of the page. ÿ Click on the Nameplate tab to go to the Nameplate page. On this page you can enter the motor rating in horsepower (HP) or kilowatts (kW). As shown below the units are in horsepower. To change the units to kilowatts, click on the HP button. ☺Helpful Tips… You can change the name of the loading categories by going to Project & Settings & Loading Categories. ÿ As shown above in the Nameplate page there is a section called “Loading”. In this area you can define the % Loading for different loading categories which you can run a study on. For example, if you want to run a Load Flow Analysis under Full Load you would open the study case editor and select Full Load under Loading Category. As a result Load Flow Analysis will run with the motor having 80% Loading as defined in the motor editor. ÿ Once you are finished making changes in the Mtr2 editor, click OK to exit the editor and save the changes. Cable Properties ÿ Open the editor for Cable22, which is located in Sub2A-N. As shown below you will be taken to the Info page. Here you can edit the ID of the cable (must be unique), the buses it is connected to, the equipment information, and length. You can also place the cable in service or out of service from this page. ÿ Instead of entering the properties of the cable in the editor manually, you can select a cable from our library to automatically fill in the required information. To select a cable from the library, click on the Library button located on the Info page. A new editor will open called Library Quick Pick – Cable where you can select the cable you want to use. Once you select the cable, click OK to close the library editor and transfer the cable properties to the editor. ☺Helpful Tips… Load Flow and Short Circuit require the cable impedance to be specified under the Impedance page. Transformer Properties ÿ Open the editor for T2 and go to the Rating page. On the rating page you can enter the value of the primary kV, secondary kV, primary winding rating in kVA or MVA, and the maximum transformer rating. Additionally, you can enter the impedance or substitute typical values for the transformer. Lumped Load Properties ÿ Open the editor for LUMP2, which is located in Sub2A-N, and go to the Nameplate page. The available fields in the rating section depend on the Model Type selected. When the Model Type is set to Conventional, the Nameplate page is as shown on the right. In the Ratings section enter the lumped load rating in MVA or MW. Furthermore, the % loading for various loading categories can be specified here. ☺Helpful Tips… You can adjust the amount of static and motor load by using the slider under Load Type. Running a Load Flow Analysis The purpose of this tutorial is to introduce the Load Flow Analysis module, and provide instructions on how to run a load flow study. In addition, an example of how to regulate bus voltage using transformer LTCs and how ETAP flags overload conditions will be given. Furthermore, there will be a brief look at the Load Flow Result Analyzer. For this tutorial you should select “Example Project (ANSI)” option when starting ETAP Demo. Example – ANSI after running load flow analysis Running Load Flow Analysis ÿ Click the Load Flow Analysis button on the Mode toolbar to switch to Load Flow Analysis mode. ÿ Running a Load Flow Analysis will generate an output report. In the Study Case toolbar, you can select the name of an existing output report to overwrite, or “Prompt.” If “Prompt” is selected, then prior to running the Load Flow Analysis you will be prompted to enter a new report name. ÿ You can customize your study by changing the options in the Load Flow Study Case editor. For example, different methods with maximum number of iterations and precision can be specified; loading and generation categories can be individually selected; load diversity factors can be applied; and finally adjustments can be selected for different elements, e.g. transformer, reactor, overload heater, cable, transmission line, and more. Viewing the Results ÿ To run the load flow study, click on the Run Load Flow button located in the Load Flow toolbar. After running the Load Flow Analysis, the results will be displayed on the one-line, as shown below: ☺Helpful Tips… Load flow analysis is carried out on all sub networks as well. ÿ The results shown on the one-line, and the format they are displayed in can be changed in the Display Options, which can be accessed from the Load Flow toolbar. ÿ To view any overload problems, simply click the Alert View button in the Load Flow toolbar. This will open a window containing a list of undersized equipment. Please note that the alert view button is disabled in the ETAP Demo. ÿ Output reports provide a way to view a more detailed and organized representation of the results. Click on Report Manager in the Load Flow toolbar, and go to the Result page and select Load Flow Report. As you can see we offer different file formats for the output report. Using the results ÿ Looking at the results on the one-line, note that the operating voltage of Bus1 is 97.89%. This caused the bus to be flagged as marginally under voltage in the Alert View window. The criteria for which a condition is flagged can be changed in the Load Flow Study Case editor. We will now use the bus voltage regulation feature of the Transformer Editor to improve our Load Flow results. ÿ ETAP allows Auto LTC settings to be applied to regulate buses that are directly or indirectly connected to a transformer. For example, we can use transformer T4 to regulate Bus1 at 100% of nominal voltage. Open the editor of T4 by double clicking on its graphic on the one-line. On the Tap page, enable (check) the Auto LTC box on the primary winding. ÿ Open the LTC settings window by clicking on the LTC box and change the Regulated Bus ID to Bus1. Click OK for both the LTC window and the Transformer Editor window. ÿ Run the Load Flow study again, with attention paid to the operating voltage of Bus1. Notice that the operating voltage of Bus1 is now within a tap step of the desired 100% regulation value. This is just one example of the many features of the ETAP Load Flow module. Analyzing the Results Load Flow Result Analyzer ÿ After running the Load Flow study, you can analyze the output data for different elements in a very compact and summarized way by using the Load Flow Results Analyzer. To do so, click on the Load Flow Result Analyzer button in the Load Flow toolbar. ÿ Select the different reports that you want to consider from the Study Reports field. If you want to compare output reports from other projects along with the current project, you can select All Project in Active Directory from the Project Report field. The other projects must be in the same directory as your current project. ÿ Select the report type from the Report Type field. The example above shows results for Loads. After selecting Loads, select the Load Types and Load Info to display. Select the units to display the results in, and the different fields that you want to display. In addition, you can create your own alerts and enable them from the Alert field. ÿ The commercial and nuclear versions of ETAP allow you to export the filtered results from the Load Flow Result Analyzer to an Excel spreadsheet.