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Consider a three-phase generator rated
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Chapter 3 Solutions
POWER SYSTEM ANALYSIS+DESIGN-EBK >I<
- An ideal transformer has no real or reactive power loss. (a) True (b) Falsearrow_forwardThe ratings of a three-phase three-winding transformer are Primary(1): Y connected 66kV,15MVA Secondary (2): Y connected, 13.2kV,10MVA Tertiary (3): A connected, 2.3kV,5MVA Neglecting winding resistances and exciting current, the per-unit leakage reactances are X12=0.08 on a 15-MVA,66-kV base X13=0.10 on a 15-MVA,66-kV base X23=0.09 on a 10-MVA,13.2-kV base (a) Determine the per-unit reactances X1,X2,X3 of the equivalent circuit on a 15-MVA,66-kV base at the primary terminals. (b) Purely resistive loads of 7.5 MW at 13.2 kV and 5 MW at 2.3kV are connected to the secondary and tertiary sides of the transformer, respectively. Draw the per- unit impedance diagram, showing the per-unit impedances on a 15-MVA,66-kV base at the primary terminals.arrow_forwardA single-phase, 50-kVA,2400/240-V,60-Hz distribution transformer has the following parameters: Resistance of the 2400-V winding: R1=0.75 Resistance of the 240-V winding: R2=0.0075 Leakage reactance of the 2400-V winding: X1=1.0 Leakage reactance of the 240-V winding: X2=0.01 Exciting admittance on the 240-V side =0.003j0.02S (a) Draw the equivalent circuit referred to the high-voltage side of the transformer. (b) Draw the equivalent circuit referred to the low-voltage side of the transformer. Show the numerical values of impedances on the equivalent circuits.arrow_forward
- A bank of three single-phase transformers, each rated 30MVA,38.1/3.81kV, are connected in Y- with a balanced load of three 1, Y-connected resistors. Choosing a base of 90MVA,66kV for the high-voltage side of the three-phase transformer. spify the base for the low-voltage side. Compute the per-unit resistance of the load on the base for the low-voltage side. Also, determine the load resistance in ohms referred to the high-voltage side and the per-unit value on the chosen base.arrow_forward1 Two transformers A and B are connected in parallel to a load of (2+j1.5)2. Their impedances in secondary terms are ZA = (0.15 + j0.5)2 and ZB= (0.1 +j 0.6)2. Their no-load terminal voltage are EA 207 /0° volt and EB = 205/0° volt. Find the power output and power factor of each transformer.arrow_forwardTwo transformersA and B are connected in parallel to a load of (2+j1.5) ohm.Their impedances in Secondary terms ZA = (0.15+j0.8) ohm and Zb = (0.1+j30.6)ohm Their no-load termind voltages are EA=200<0 V and EB=210<0 Volt.Find the power and Power factor of each transformer? %3D %3Darrow_forward
- Two single-phase transformers whose phase electrical equivalent circuits are given below are connected in parallel and ZL= 0.8+j0.6ohm is feeding a worth of load. Idle operating voltage of Transformer 1 is 220 V and Transformer 2 idle operating voltage is 240V.a.) Find the currents flowing from transformers to the load.b.) Find the active powers that transformers transfer to the load.arrow_forwardNo-load operation and short circuit tests were performed on three-phase, 50 Hz 480/220 delta / Y connected transformer. In these testsThe line voltage, line current and three-phase total power have been measured from the high voltage windings and the test results are below.pictures. 100 A DC current when 1.08 V DC voltage from non-transferable software is applied to the low voltage windingshas attracted.Find the single phase equivalent circuit parameters of this transformer.idle test:Voltage: 480V Power:114w current: 0.71Ashort circiut test:V: 10v P: 78w c: 18.3aarrow_forwardNEAT EXPLAIN NEEDED( CORRECT ANSWER NO GPT PLEASE)arrow_forward
- in distribution transformers; What is 30 degrees phase shift in delta-star connection? What are the disadvantages? (can you explain with drawing?)arrow_forwardََQ/ 400/200 V, single-phase transformer is supplying a load of 50A at a power factor of 0.866 lagging. The no-load current is 2A at 0.208 p.f. lagging. .. Find The primary current is ...... A * The primary power factor is ........ lagging *arrow_forward1-A single-phase power system is shown in Figure below. The power source feeds a 100- kVA 14/2.4-kV transformer through a feeder impedance of 40.0 + j150 &. The transformer's equivalent series impedance referred to its low-voltage side is 0.12 + j0.5 &. The load on the transformer is 90 kW at 0.80 PF lagging and 2300 V. 40n j150n 0.12n j0.5n Load 90 kW 0.85 PF lagging source Source Feeder Transformer Load (transmission line) (a) What is the voltage at the power source of the system? (b) What is the power losses in the feeder?arrow_forward
- Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage Learning