- Studi Stud For The System Shown In Figure 1 And Starting From Data That Are Given There Carry Out The Following 1 Gi 1 (53.3 KiB) Viewed 29 times
Studi Stud For the system shown in Figure 1, and starting from data that are given there, carry out the following. 1. Give the equivalent diagram and calculate the RMS of the maximum short circuit current at busbar (lach. 2. Calculate the rated currents Is... and I 3. Select the transformation ratio (CTR) of the current transformers CT CT and CT. Standardized rated primary current: 5A, 10A, 15A, 20A, 25A, 30A, 40A, 50A, 75A, 100A, 150A, 200A. 250A. 300A 350A, 400A, 450A, 500A, 600A, 700A, 800A, 900A, 1000A, 1250A, 1500A. 4. Determine the Pickup current (TAP) of relays 1, 2 and 3. 5. Determine the instantaneous setting of relays 1, 2 and 3. 6. Determine the TDS of relay 1, 2 and 3 to answer a coordination protection arrangement Unstream 750 MVAS U69 kV Sse - 750 MVA Sect E: A Transformers TR and TR.) 69/13.8kV 20 MVA 7% -10 TR 8. TR B 1-10914.3A CTR OCR 3 Transmission Line (TL) Zin -1.25 (reference 13.8 kV) Load characteristics (Load) Rated power S=9 MVA Current Transformer characteristics (CTI, CT2 and CT3) Standard input = 5A Ce core transformer TL CTR OCR 2 с CTR Overcurrent Relay characteristics (OCRI) Current Setting: 125% Overcurrent Relay characteristics (OCR2) Current Setting: 150% Overcurrent Relay characteristics (OCR3) Current Setting: 100% OCRI Load Take into account the following considerations: The discrimination margin to be 0.3s Instantaneous setting: 1 to 300A in step of 1A. All relays have inverse time characteristics as shown in Figure 2 Figure 1 Page 1/4