Can you guys do it by 28 th may
AV /2019 1 RMIT University, School of Engineering EEET2380/ EEET2381 Advanced Power Systems Assignment Objectives: The main objective of this assignment is applying your knowledge gained from Advanced Power Systems Course on following topics: Load-Flow Analysis, Power System Dynamic/ Transient Stability, Power System Voltage Control. Network Setup Download “AP_Assignment.pfd” and save it in your computer. Open the DIgSILENT Power Factory (PF) and then go to: “File>>Import>>Data (*.pfd,*.dz,*.dle)”. Then select the “AP_Assignment.pfd” file from the place where you saved it in the computer and then click “Open”. Then activate the project: “File>>Activate Project” and select the project “AP_Assignment” and press “OK”. A schematic of the network model is shown in Figure 1. Fig. 1: IEEE-14 Bus System. AV /2019 2 Assignment Tasks: Assume that you are a Power System Planning Engineer working for a Power Utility Company. The Chief Engineer in the power system planning department asked you to conduct a system study for a New 50 MW Wind-farm installation. Assume that your network model is the IEEE-14 Bus System and the 50 MW Wind Farm is connected to the MV Network (33 kV) of the IEEE-14 Bus System. The Wind Farm is connected to the IEEE-14 bus system through a 33 kV Feeder (See Fig. 2). The following connection options are available for the wind farm: Table 1: Wind Farm Connection Options IEEE-14 Connection Point Feeder Length Feeder Impedance Bus-13 45 km 0.3+0.3 Ω/km Bus-14 55 km 0.3+0.3 Ω/km Conduct following studies to determine the impact of the 50 MW wind farm installation on the network and determine the best connection point for the wind farm. 1. First determine the steady-state bus voltage magnitudes, voltage angles, steady-state rotor angle of each generator after running a load flow calculation. Record these values in a Table. Hint: Steady-state rotor angle could be determined by “Calculating Initial Conditions” and then placing the mouse over each generator result box. The variable name for steady-state rotor angle is “fipol” (i.e. The 3rd value in the synchronous generator result box). 2. Active (P) and Reactive (Q) Power sensitivity analysis: Keeping all other variables constant, change the active power P of load on Bus_3 & Bus _12. Starting from their initial values, increase the value of P in steps of 5 MW till you reach a value more than 30 MW from their initial value for each bus separately. At each step note the magnitude and angle of Bus_3 & Bus_12 and total power losses in the system. Record values in a Table. Now, set the P value of the Load at Bus_3 & Bus _12 to the original value. Keeping all other variables constant, change the reactive power Q of load on Bus_3 & Bus _12. Starting from their initial values, increase the value of Q in steps of 5 MVAR till you reach a value more than 30 MVAR from their initial value for each bus separately. At each step note the magnitude and angle of Bus_3 & Bus_12 and total power losses in the system. Record values in a Table. Draw graphs of Bus_3 & Bus _12 voltage magnitude and angle versus the Q MVAR of Load at Bus_3 & Bus _12. Also plot the total active power loss in the system versus the Q MVAR of the load at Bus_3 & Bus _12. Choose appropriate scales for the graphs. Based on the results you obtained, which network (HV or MV) is more sensitive to active and reactive power? Support your answer with a theoretical explanation. 3. Now apply 50 ms three-phase short-circuit faults at the following locations in the network; Set the P & Q values of the Load at Bus_3 & Bus _12 to the original value before the simulation. a) Bus_3; b) Bus _12. (apply separately for each bus) Plot the synchronous generator rotor angles for G1, G2, G3, G6 and G8 during these faults for a period of 10 s. Hint: Use “Dynamic Simulation Functionalities Guide” for conducting the dynamic simulations with DIgSILENT PF and Plotting Graphs. AV /2019 3 4. Now increase the fault duration for above fault cases (i.e. fault at Bus_3 and Bus_12) and determine the Critical Clearing Time (CCT) for both fault cases. Hint: Increase the three-phase short-circuit fault duration in 10 ms steps 5. Now connect the wind farm to the IEEE-14 bus system considering configuration shown in Fig. 2 and data provided in the Table-1. You can choose a value between 0.1 – 0.15 pu as the 0.69/ 33 kV Step-up Transformer Reactance (x1). 33 kV 33 kV0.69 kV 0.69/33 kV IEEE-14 Bus System (Bus-13 or Bus-14) 33 kV Feeder 50 MW Wind Farm Fig. 2: Wind Farm Configuration. Hint: You can use the DIgSILENT PF Wind Generator Model (“ ”), for the 50 MW Wind Farm. In the Wind Generator Load Flow Page set the “Local Controller” to “ConstQ”. Also set the Active Power to 50 MW. 6. After connecting the wind farm (for both Bus-13 & Bus-14 under separate instances), determine the steady-state bus voltage magnitudes, voltage angles, steady-state rotor angle of each generator after running a load flow calculation. Record these values in a Table. Are these values significantly different from the values you recorded for Step-1? (Prior Connecting the Wind Farm) 7. What is the steady-state voltage magnitude at the wind farm (for both Bus-13 & Bus-14 under separate instances)? If it is more than 1.1 pu, determine the best control mode for the Wind Generator “Local Controller” to maintain bus voltage below 1.1 pu. 8. Is there any impact on IEEE-14 bus system connection point (i.e. Bus-13 & Bus 14), voltage by the control mode you proposed for the wind generator? If such issues exist, what you wish to propose to fix it? Hint: Always bus voltages must be maintained between 0.95 – 1.10 pu. 9. With the proper “Local Controller” for the wind-farm (Step-7) and appropriate voltage control solution for the Step-8 repeat the same sensitivity study in Step-2 for both wind farm connection options (i.e. Bus-13 & Bus 14). Does the Active (P) and Reactive (Q) power sensitivity change substantially compared to Step-2 for both wind farm connection options (i.e. Bus-13 & Bus 14)? 10. With the proper “Local Controller” for the wind-farm (Step-7) and appropriate voltage control solution for the Step-8 repeat the dynamic simulations in Step-3 & Step-4. Does the CCT change substantially compared to Step-4? 11. Considering both the steady-state results (Stead-State Voltages, Active & Reactive Power Sensitivities) and Dynamic Results, determine the best location to connect the 50 MW wind-farm to the IEEE-14 bus system. Hint: For the best connection option, you should consider minimum voltage violations (maintained 0.95 – 1.1 pu), higher CCT, and minimum system losses. AV /2019 4 Notes: This Assignment is based on IEEE-14 System, and this system is originally designed as a 60 Hz system (Since it is a US based Test System). Therefore, for every NEW Element you include in the model, such as Wind Generator, Transformer etc. you should use 60 Hz as the system frequency. How to Submit the Assignment? You should present all the results obtained for each step (step 1 to step 11) in a report with sufficient discussion for each step. Submit your MS Word or PDF file with your DIgSILENT file through Canvas Assignment Submission System following the directions given in Canvas before the deadline. Assignments submitted after the deadline but within one week from the deadline will attract a penalty of 20 marks. Assignments submitted after one week from the respective deadlines will not be marked (0 marks). Network Setup Assignment Tasks: Assume that you are a Power System Planning Engineer working for a Power Utility Company. The Chief Engineer in the power system planning department asked you to conduct a system study for a New 50 MW Wind-farm installation. Assume that your network m... Table 1: Wind Farm Connection Options Conduct following studies to determine the impact of the 50 MW wind farm installation on the network and determine the best connection point for the wind farm. 1. First determine the steady-state bus voltage magnitudes, voltage angles, steady-state rotor angle of each generator after running a load flow calculation. Record these values in a Table. Hint: Steady-state rotor angle could be determined by “Calculating Initial Conditions” and then placing the mouse over each generator result box. The variable name for steady-state rotor angle is “fipol” (i.e. The 3rd value in the synchronous gener... 2. Active (P) and Reactive (Q) Power sensitivity analysis: Keeping all other variables constant, change the active power P of load on Bus_3 & Bus _12. Starting from their initial values, increase the value of P in steps of 5 MW till you reach a value more than 30 MW from their initial value for each bus separ... Now, set the P value of the Load at Bus_3 & Bus _12 to the original value. Keeping all other variables constant, change the reactive power Q of load on Bus_3 & Bus _12. Starting from their initial values, increase the value of Q in steps of 5 MVAR til... Draw graphs of Bus_3 & Bus _12 voltage magnitude and angle versus the Q MVAR of Load at Bus_3 & Bus _12. Also plot the total active power loss in the system versus the Q MVAR of the load at Bus_3 & Bus _12. Choose appropriate scales for the graphs. ... Based on the results you obtained, which network (HV or MV) is more sensitive to active and reactive power? Support your answer with a theoretical explanation.