3. Draw an Impedance & Reactance diagram for the electric power system shown in the figure showing all the impedances in per unit. Choose the generator as the base. The three-phase and line-to-line ratings are given below G:100 MVA, 20 KV, X = 9% T1: 90 MVA, 20/200 KV, X-15% T2: 90 MVA, 200/20 KV, X=20% M: 90 MVA, 18 KV, X= 8% Line: 200 KV, X=120 22 GENERATOR TRANSFORMER T₁ LINE TRANSFROMER T₂ MOTOR

3. Draw an Impedance & Reactance diagram for the electric power system shown in the figure showing all the impedances in per unit. Choose the generator as the base. The three-phase and line-to-line ratings are given below G:100 MVA, 20 KV, X = 9% T1: 90 MVA, 20/200 KV, X-15% T2: 90 MVA, 200/20 KV, X=20% M: 90 MVA, 18 KV, X= 8% Line: 200 KV, X=120 22 GENERATOR TRANSFORMER T₁ LINE TRANSFROMER T₂ MOTOR

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

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.25P: Consider a single-phase electric system shown in Figure 3.33. Transformers are rated as follows:...

See similar textbooks

Similar questions

Problem 1 - Series en Parallel AC networks [19] Look at the circuit in Figure 1 and determine the following: (a) Total Admittance. (b) Total Impedance. (c) Total Current (l:). (d) Current (I1) through impedance Z2. (e) Current (12) through impedance Z3. (f) Current (I3) through impedance Z4. (g) Is this an inductive or capacitive circuit? A. B Zs 220V;50HZ Figure 1 (h) Voltage across Z1. (i) Voltage across A and B. G) Voltage across Zs. Z1 = 3 + j5 ohm Z2 = 10 + jo ohm Z3 = 5 + j15 ohm Z4 = 10 – j30 ohm Zs = 20 – j30 ohm Admittance and Impedance in rectangular notation. All currents and voltage in polar notation. Take voltage as reference.
In the system shown in Figure 1, the transformers are connected star-star with both star points grounded and the generators are connected in star with thier star points grounded. The system base is 15 MVA. The transformers all have reactances of 0.04 p.u. on this 15 MVA base. The reactances of all other elements are given in Table 1 (in 2) and the voltage levels are given in Table 2. p.u. G1 p.u. T1 jö Per-Unit Convert all values to p.u. on a 15 MVA base. Xa= p.u. Xc₂= XL = V BABE G1 2 X 9 T3 Figure 1: A section of the distribution system T1 L Table 1: Sequence reactances (2) 3 G1 L G2 0.3 0.59 0.01 4 L 9/10 10 Fault Voltage What is the voltage at bus 3 (in Volts) after the fault has occurred? Vp= V T2 5 T2 34 10/4 Table 2: Voltage bases (kV) G2 4 T3 10/9 | G2 Fault Current A three-phase fault with a fault reactance of 0.01 p.u. occurs at bus 3. Calculate the fault current flowing at the fault point in KA. Ip=-j KA So
Three zones of a single-phase circuit are identified in the figure with a generator voltage specification of 240 V. The zones are connected by the transformers T1 and T2, whose ratings are shown below.Using base values of 30 kVA and 240 volts in zone 1, draw the pu circuit and determine the pu impedance and pu source voltage. Then calculate the load current in pu and in amperes.*Round the final answer to four decimal places, polar form, and label it with the correct units.
e = 0 Q1: What does happen if we change two currents? a. Q2: What does happen if we have a three-phase four poles machine? Q3: What does happen if we have a two-phase two poles machine? e = 0 Q4: What does happen if we apply a capacitance in phase b and then use same voltage for both phase. Dr. Ali Ki. pw --
Connect three single-phase transformers in Y-Y, with subtractive polarity, so that the line-to-line voltages on the primary are 30 degrees delayed to their respective line-to-line voltages on the secondary. It should show each step that is needed to make this connection (example: the phasor diagram) and should show the final connection of the three transformers including the polarity markings. Assume phase A on the primary is terminal "H1".
What is the main direct cause of reactive power in AC system?A. Resistance of transmission linesB. Inductance and capacitance in the loadsC. Ideal transformer connected in the systemD. Power produced by generator
Q4/For the three-phase power network shown in Figure. the various components are: GI: 100 MVA, 0.30 pu reactance. G2: 60 MVA, 0.18 pu reactance. Transformers (cach): 50 MVA, 0.10 pu reactance. Inductive reactor X: 0.20 pu on a base of 100 MVA. Lines (each): 80 ohms (reactive); neglect resistance. with the network initially unloaded and a line voltage of 110 kV, a symmetrical short circuit occurs at midpoint E of line 2. Calculate the short circuit MVA to be interrupted by the circuit breakers A and B at the ends of the line. T3 38 L1 L2 G2 Bas 12 T4 Bus
If you have 3-phase power and you need to step down (or up) in 3-phase voltage, how many single-phase transformers are needed? Explain.
1. How do you measure three phase line currents by using two current transformers? Draw the connection scheme.
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
2) The one-line diagram of a three-phase power system is as shown in Figure. Impedance are marked in per-unit on a 100-MVA, 400-kV base. The load at bus 2 is S2=15.93 MW - j33.4 Mvar, and at bus 3 is S3-77 MW + j14 Mvar. It is required to hold the voltage at bus 3 at ...L0 kV. Working in per-unit, determine the voltage at buses 2 and 1. (Please determine the voltage magnitude within the specified limits: 410-450 V. By considering the voltage magnitude value you determined yourself, solve the question.) V₁ j0.5 pu V₂ j0.4 pu S₂ Figure V3 S3
The reactance of a generator is given as 0.25 per-unit based on the generator’s of 18 kV, 500 MVA. Find its per-unit reactance on a base of 20 kV, 100 MVA. a. 0.0505 b. 0.0605 c. 0.0405 d. 0.0606