A new industrial development has decided to'use two 350 kVA single-phase transformers to serve as an interim 3-phase 13.2 kVu- 600 V step-down transformer bank. The transformers are to be connected open-delta on the HV side and open-delta on the LV side. (a) What are the voltage ratings of the two single-phase transformers? Determine the maximum balanced three-phase apparent power load that can be continuously supplied by this bank. (b) (c) If at a later date a third identical single-phase transformer is added to the bank, what will be the new three-phase apparent rating of the completed delta-delta bank?

A new industrial development has decided to'use two 350 kVA single-phase transformers to serve as an interim 3-phase 13.2 kVu- 600 V step-down transformer bank. The transformers are to be connected open-delta on the HV side and open-delta on the LV side. (a) What are the voltage ratings of the two single-phase transformers? Determine the maximum balanced three-phase apparent power load that can be continuously supplied by this bank. (b) (c) If at a later date a third identical single-phase transformer is added to the bank, what will be the new three-phase apparent rating of the completed delta-delta bank?

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

See similar textbooks

Similar questions

A 12 MVA, 132/6.6 kV, transformer having a reactance of 0.15 pu is fed from an infinite bus. The transformer feeds two motor each 6 MVA, 6.6 kV. Each motors has a transient reactance of 0.14 pu and a subtransient reactance of 0.30 pu based on its own rating. A three phase balanced fault occurs at the terminals of one motor as shown in the figure below. Find the subtransient fault current and subtransient current in breaker. M1) 132/6.6 KV СВ 38 CB Infinite Bus M2 Fault
The capacity of each transformer in a 3-phase A/A transformer bank is 250 kVA. If a balanced star load is connected across it and is taking 750 kVA. Now due to some reasons, the transformer bank starts operating as open delta connection. The percentage overloading on the bank in open delta connection is
2. Given three identical ideal single-phase transformers with each rated at 100KVA and 7kV/3.5kV, they are connected as a three-phase transformer bank. The three-phase transformer has high voltage side connected in delta and the low voltage side is connected in wye. A three-phase 200KVA, wye connected load is connected at the low voltage side of the transformer. Calculate the following: a. Rated line-to-line voltage on each side b. Line current on each side of the transformer
When the transformer is loaded in a balanced fashion up to its nominal rating (10 MVA), calculate the high side line-to-line phasor voltages (ab, bc, ca). and low side phasor voltages both line-to-line and line-to-neutral (ab, bc, ca, a, b,c). as a reference for calculations the low side A line to neutral voltage is 7620V at an angle of 0 degrees when the transformer is at rated power. The transformer has the following characteristics: V: 138kV delta high side/ 13.2 kV wye low side 9% impedance X/R ratio of 20
Two single-phase transformers, having equal turns ratio, in parallel supply a secondary load of 1,000 A at 0.8 pf lagging. For each transformer the secondary emf on open circuit is 3,300 V and their total leakage impedances referred to secondary are (0.10 + j0.20) ohms and (0.05 + j0.040) ohm, respectively. Determine the output current on each transformer.
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 13.2 (line-to-line) kV. The step-down transformer has a turn ratio of 15:1 and it has a Y-connected, balanced load of 0.667 +j 0.111 ohms connected to its secondary side. A capacitor bank of -j0.239 ohms is added parallel to the load. Assuming an ideal transmission line, the load voltage (line-to-neutral) would be: A. 5118 V B. 6.2 kV C. 8865 V D. None of the other choices are correct E. 4225 V
The required no-load voltage ratio in a 150 kVA single-phase 50 Hz core-type, two-winding transformer is 5000/250 V. Calculate the load kVA for maximum efficiency. The full-load I2R loss is 1800 W and the core loss is 1500 W. Round your answer off to the nearest whole number
2) 9.2Three - 25 KVA single-phase transformers are connected in delta – delta. One of the transformers has been defected. What is the maximum real power that the transformer bank can deliver at a power factor of 0.8?
Three single phase transformers are connected in a Delta-Wye configuration. Each transformer is rated 13kV/64kV. The transformers are connected to a 3 phase 13kV (L-L) supply and the balanced three phase load is 788KVA. What is the current magnitude in the secondary winding of each transformer? explain the steps too please
A 10 MVA three phase load is to be served by a three phase transformer at aline voltage of 13.8 kV. The supply side voltage(line-line) is 138 kV. Varioussingle phase transformers are available in the warehouse but all havewindings with voltage ratings under 100 kV and current ratings under 250 A.Is it possible to serve the load using only three single phase transformers? Ifso, specify the three phase connections and the low and high voltage ratingsof the single phase transformers.
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
In the system shown in Figure 1, the transformers are connected star-star with both star points grounded and the generator is connected in star with its star points grounded. The per unit impedances of each element on a 40 MVA base are given in Table 1 and the voltage levels are given in Table 2. Z [p.u.] 0 2 tööt Generator 0.01 +j0.08 p.u. L Figure 1: A section of the distribution system Transformer T1 Line V BASE [KV] 0.04 + j 0.03 + j 0.15000000000000002 0.06000000000000000 Generator Table 1: Sequence impedances (p.u. on 40 MVA base) 3 T2 181. Line 3 10 Table 2: Voltage bases (kV) Load 1 Transformer T2 Load Current A load current of 11.316 kA is flowing with a lagging power factor of 90 %. Convert this to a current vector in per-unit. IL = 0.04 + j 0.06000000000000000