You are the engineer responsible for parameterizing the relay of a substation with a 500kVA transformer, transformation ratio of 13.8-0.38/0.22kV and impedance of 4.5%. The local network sent you a new equivalent impedance at the delivery point and the relay installed in the primary cabin activated function 50, disabling the medium voltage switch. Remembering that the primary cabin has a protective CT of 150:5A and TP with a transformation ratio of 13800/R3:115/R3 resulting in an RTP of 120:1. A) Calculate the symmetrical three-phase short circuit level in the primary cabinet to determine the current passing through the relay reading during a fault.

You are the engineer responsible for parameterizing the relay of a substation with a 500kVA transformer, transformation ratio of 13.8-0.38/0.22kV and impedance of 4.5%. The local network sent you a new equivalent impedance at the delivery point and the relay installed in the primary cabin activated function 50, disabling the medium voltage switch. Remembering that the primary cabin has a protective CT of 150:5A and TP with a transformation ratio of 13800/R3:115/R3 resulting in an RTP of 120:1. A) Calculate the symmetrical three-phase short circuit level in the primary cabinet to determine the current passing through the relay reading during a fault.

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter13: Transmission Lines: Transient Operation

Section: Chapter Questions

Problem 13.24P

See similar textbooks

Similar questions

3. A 220 V /345 kV, 200 kVA testing transformer to be used for cable testing has 10% leakage reactance and 2% resistance. The cable has to be tested at 600 kV, 60 Hz while charging current is 0.5A. Find the required value of the series inductor to be connected with the transformer to achieve resonance. Assume (Rind=1.8% of Xind). Find the primary voltage of the transformer during this test. Also calculate rated current of this transformer and the input power
Given three phase fullwave with center tapped transformer with 220 Vac source voltage, determine: Vdc, Vrms, Pdc, RF, and efficiency. D1 L1 D2 L1 L7 D3 220 Vac, 60 Hz Vo D4 RL=10 ohms L2 D5 L3 D6 m. L6 3 F12 87
A short transmission line connects a step-up transformer on the source side with a series impedance of j0.5 ohms (referred to the primary) to a step-down transformer on the load side with a series impedance of 50 ohms (referred to the primary). The turn ratio of the step-up transformer is 1:10 and a no-load primary voltage of 23 (line-to-line) kV. The step-down transformer has a turn ratio of 35:2 and it has a Y-connected, balanced load of 0.490 +j 0.0816 ohms connected to its secondary side. Assuming an ideal transmission line, compute the load voltage (line-to-neutral).
A short transmission line connects a step-up transformer on the source side with a series impedance of j0.5 ohms (referred to the primary) to a step-down transformer on the load side with a series impedance of 50 ohms (referred to the primary). The turn ratio of the step-up transformer is 1:10 and a no-load primary voltage of 23 (line-to-line) kV. The step-down transformer has a turn ratio of 35:2 and it has a Y-connected, balanced load of 0.490 +j 0.0816 ohms connected to its secondary side. A capacitor bank of -j0.171 ohms is added parallel to the load. Assuming an ideal transmission line, the load voltage (line-to-neutral) would be: O A. 7360 V O B. 6.2 kV O C. 12750 V O D. 4806 V O E. None of the other choices are correct
90KVA, 460/230 3Phase transformer, Determine the Primary Conductor Size (include the AWG size number), Secondary Conductor Size (include the AWG size number), Primary Protection Breaker, and Secondary Protection Breaker. uarn
A short transmission line connects a step-up transformer on the source side with a series impedance of j0.5 ohms (referred to the primary) to a step-down transformer on the load side with a series impedance of 50 ohms (referred to the primary). The turn ratio of the step-up transformer is 1:14 and a no-load primary voltage of 17 (line-to-line) kV. The step- down transformer has a turn ratio of 18:1 and it has a Y-connected, balanced load of 0.463 +j 0.0772 ohms connected to its secondary side. A capacitor bank of -j0.324 ohms is added parallel to the load. Assuming an ideal transmission line, the effective impedance (per phase) of the system seen by the source would be: O A. 0.292 + j0.375 O B. None of the other choices are correct O C. 0.584 + j0.750 O D.0.196 + j0.158 O E. 5.84 + j7.5
A short transmission line connects a step-up transformer on the source side with a series impedance of j0.5 ohms (referred to the primary) to a step-down transformer on the load side with a series impedance of 50 ohms (referred to the primary). The turn ratio of the step-up transformer is 1:14 and a no-load primary voltage of 17 (line-to-line) kV. The step-down transformer has a turn ratio of 18:1 and it has a Y-connected, balanced load of 0.463 +j 0.0772 ohms connected to its secondary side. Assuming an ideal transmission line, the real power absorbed by the load would be: A. 42 MW B. None of the other choices are correct C. 54 MW D. 37.4 MW E. 28 MW
answer for the question. Which of the following conditions would be necessary in order for you to use an r-f transformer as a very sharply tuned band-pass device? OA. A series-tuned LC circuit must be connected across the secondary winding. OB. The primary and secondary windings should be overcoupled. O C. The primary and secondary windings must be shielded from each other. OD. A capacitor should be connected between the primary and secondary windings.
- A 150 KVA, 0.4/250 kV testing transformer has 10% leakage reactance and 4% resistance on 150 kVA base. A cable has to be tested for 500 kV using this transformer at a resonant frequency of 50 Hz. If the charging current of the cable at 500 kV is 0.4 A. Assuming 1.5% resistance for the inductor to be used and the connecting leads and neglecting dielectric loss of the cable, calculate: 1.2.1 The series inductance required 1.2.2 The input voltage of the transformer and power (kW).
A short transmission line connects a step-up transformer on the source side with a series impedance of j0.5 ohms (referred to the primary) to a step-down transformer on the load side with a series imnedance of 50 ohms (referred to the primary). The turn ratio of the step-up transformer is 1:14 and a no-load primary voltage of 17 (line-to-line) kV. The step-down transformer has a turn ratio of 18:1 and it has a Y-connected, balanced load of 0.463 +j 0.0772 ohms connected to its secondary side. Assuming an ideal transmission line, the load voltage (line-to-neutral) would be: y50 O A. 14.2 kV O B. 6.52 kV O C. 17.2 kV O D. 5.07 kV O E. None of the other choices are correct
A single-phase transformer has a voltage ratio on open circuit of 7900/660 V. The primary and secondary resistances are 0.55 ohm and 0.035 ohm respectively. The corresponding leakage reactances being 4.22 ohm and 0.18 ohm. The load is equivalent to a coil of resistance 3.85 ohm and inductive reactance of 4.2 ohm. Determine the terminal voltage of the transformer and the output in kW when supplying a given load using approximate equivalent circuit when the applied voltage is 7912 V. Your answer
design 800v to 14.5v isolated bi-directional dcdc conveter a. choose the converter type with reason b. design each components with safety margin 30% (equations) c. calculate the efficiency (equations)