Question 1: (35 marks)
The following table provides single core copper conductors, PVC insulated cable.
For a 3 phase, 380V, 150kW synchronous motor with a 0.8763 p.f lagging which is located in a location 150 m away from the power generation station:
Calculate the size of a suitable PVC insulated aluminum cable and discuss using the available cable, should we start the motor using start-delta (Ist = 3 IFL) or VFD (Ist = IFL)? (10 marks)
Table 1: Physical and electrical properties of copper conductor cables
Open the given Cable sizing pdf file in PowerFactory software. Using Export in PowerFactory and make sure activate it.
Figure 1
You need to verify your calculation in Question 1(a) with the given model. Change the values of motor and cable as per your calculation. You MUST add screenshots for the changed motor power output page (as shown in Figure 2) and cable parameters page (as shown in Figure 3). (10 marks)
Change the motor power output as the given data. Instructions are given as follows:
Figure 2
Change the line data as per your calculation. Instructions are given as shown in Figure 3.
Figure 3
Click the Calculate Load Flow > Execute as shown in Figure 4:
Figure 4
Clarify the cable loading (in %) and Amps value, and voltage (voltage drop) at motor connection point and verify with your (10 marks)
Explain if there is any discrepancy in the simulated and calculated values and (5 marks)
Question 2: (35 marks)
Series and Shunt compensation and power factor improvement:
Shunt compensation: Open the given Series and Shunt pdf file in PowerFactory software. You will find the following MV/LV network.
Figure 5 Shunt compensation
Click Calculate Load Flow as shown in Figure 4. You will find that the voltages at points are not within 2% of its nominal value. You can check the nominal value by double-clicking the particular bus (line-line and line-ground value). Adjust the capacitor value and its location at Terminal (1) and Terminal (2) to determine the capacitor size to increase the voltage so that the value is within 2% of its nominal value.
Draw a table for capacitance and bus voltages for different values of (10 marks)
Provide a screenshot of the final load flow which satisfies the condition of 2% of the nominal (5 marks)
How to change the capacitor value: Double click the Shunt/Filter > Rated Reactive Power (MVar) and change the nominal voltage according to the voltage at the point of connection.
Figure 6
How to change the capacitor location:
Figure 7
Series compensation: To activate the series connection circuit, Click Series connection,
Activate as shown below (left) and network as shown on the right.
Figure 8
Now double click the Series Capacitor > Go to Load Flow tab > Change the value of
Capacitance (in F), beyond 1mF.
Draw a table for capacitance and bus (5 marks)
Provide a screenshot of the final load flow which satisfies the condition of 2% of the nominal value. (5 marks)
Explain the observed differences for series and shunt compensation. (10 marks)
More information on Modelling in PowerFactory can be found in the following links:
- Introduction to DigiSILENT PowerFactory – Basic Load Flow Analysis
- Load flow analysis using Digsilent PowerFactory
Question 3: Pre-recorded Presentation (20 marks)
Create and submit a Loom video with webcam ON (showing your face) and a screen capture showing how you run the simulation and change different parameters of the model. The video length for each requested question should NOT be more than 5 minutes. So, practice well before recording.
Guidelines on how to create a Loom video:
https://www.loom.com/share/159e007948ce4cb8acfee8a99615f388
Requirements:
Create a Loom Video:
(a) Introduce yourself.
(b) Demonstrate how you run the simulation model and change its
(c) Analyse/Explain (speak) the process while you are running the simulation/changing the parameters. Paste the link of your recording as a response to the corresponding
Create a 5-minute video demonstrating the following:
- Walkthrough the simulation setup process, explaining each
- Run the simulation while narrating what is happening in real
- Analyse the results, discuss key observations and explain what the data signifies in the context of the simulation.
- Provide insights or conclusions based on your
Question 4:
- What skills or knowledge did I gain from this project/task and how can I apply these in the future projects? (5 marks)
- What were the key challenges I faced during this project/task and how did I overcome them? (5 marks)
END OF ASSESSMENT