Per Unit Definition - System quantities defined as the fraction of the base quantities.
Three advantages -
1. Easy for handling large calculation
2. Per Unit impendence of Hv or Lv side of transformer remains the same
3 Per unit values can be easily used in digital computation
QUESTION 5 a) Define the Per Unit system and list three (3) main reasons of using Per Unit system...
1. The one-line diagram of a three-pha se power system is shown in Figure 3.29. Select a common base of 100 MVA and 15 kV on the motor side. Draw an impedance diagram with all impedances including the load impedance marked in per-unit. The manufacturer's data for each device is given as follow:The three-phase load at bus 4 absorbs 57 MVA, 0.6 power factor lagging at 10.45 kV. Line 1 and line 2 have reactances of 48.4 Ω and 65.43...
The three-phase power and line-line ratings of the electric power system shown in Figure 2 are given below T2 2 Line Vm G M 1 BA Figure 2 One-line diagram for problem 2 G: Ti: T2: Line: M: 60 MVA 50 MVA 50 MVA 20 kV 20/200 kV 200/20 kV 200 kV 18 kV X=9% X=10% X=10% Z=120+j2002 X=8% 43.2 MVA (a) Draw an impedance diagram showing all impedances in per unit on a 100-MVA base. Choose 20 kV as...
2 - The three-phase power and line-line ratings of the electric power system shown in Figure 2 are given below. Ti T2 VA Line 2 G M Vm BE BE Figure 2 One-line diagram for problem 2 G: T: T2: Line: M: 60 MVA 50 MVA 50 MVA 20 kV 20/200 kV 200/20 kV 200 kV 18 kV X=9% X=10% X=10% Z=120+j2002 X=8% 43.2 MVA (a) Draw an impedance diagram showing all impedances in per unit on a 100-MVA base....
The three-phase power and line-line ratings of the electric power system shown in Figure 2 are given below. T1 T2 V. 1 2 vm 9 Line G M Figure 2 One-line diagram for problem 2 G: T1: 60 MVA 50 MVA 50 MVA T2: Line: M: 20 kV 20/200 kV 200/20 kV 200 kV 18 kV X=9% X=10% X=10% Z=120+j200 12 X=8% 43.2 MVA (a) Draw an impedance diagram showing all impedances in per unit on a 100-MVA base. Choose...
Transformer TI : 50 MVA, 10 kV Y/138 kV Y, X=0.10 per unit; Transformer T2: 100 MVA, 15 kV D/138 kV Y, X-0.10 per unit; Each 138-kV line: X1-400 A three-phase short circuit occurs at bus 5, where the prefault voltage is 15 kV. Prefault load current is neglected. (a)Draw the positive-sequence reactance diagram in per-unit on a 100-MVA, 15-kV base in the zone of generator G2. Determine: (b) the The'venin equivalent at the fault, (c) the subtransient fault current...
Consider the single-line diagram of the three-phase power system shown in Figure 1. Component ratings are as follows: Generator G1: 750 MVA, 18 kV, X0.2 per unit Generator G2: 750 MVA, 18 kV, X 0.2 per unit Synchronous Motor M: 1,500 MVA, 20 kV, X-20% A-Y Transformers Ti, T2, T's, & T.: 750 MVA, 500 kV Y/20 kV A, X = 10% Y-Y Transformer T's 1,500 MVA, 500 kV Y/20 kV Y, X-10% ne L:X (a) Using bases of 100...
Please show all the clearly step Y11 ist j30 and Y44 isnt -j12.85 Consider the 4-bus power system shown in Fig. 1. The system parameters are given below: 50 MVA, 20 kV, X-2090 40 MVA, 20 kV, X-20%, X, = 5% 50 MVA, 20 kV Δ /110 kV Ý, X= 1090 50 MVA, 20 kV MI 10 kV Ý, X= 10% Xi-24.2 Ω Generator G: Motor M: Transformer T1 : Transformer T2 : Transmission line: 3 4 T2 nu)M Fig....
Fig Qshows the one-line diagram of a three-phase power system. As shown in Fig. Q3. the two zones are connected by a 400 MVA, 240-kV/24-kV, Ý-A three phase transformer. The Y-A three phase transfonmer has an equivalent series impedance of ZTH - 1.2 + j1.6n per phase referred to the high voltage side (primary side). The three-phase power system can be studied with per unit quantities using base values of S-500 MVA and 240 kV in zone 1. By using...
3) The single-line diagram of a three-phase power system is shown in Fig. 1. Equipment ratings are given as follows: G1 1,000 MVA, 15.0 kV, 20.18, o 0.07 pu G2 : 1,000 MVA. 15.0 kV, 攻=エ1 =エ2 = 0.20, ro = 0.10 pu G3 : 500 MVA, 13.8 kV. 1" = 띠 z2 = 0.15, zo 0.05 pu G4 : 750 MVA, 13.8 kV. ェd =ェ1 = 0.30, T2 = 0.40 ro = 0.10 pu Ti : 1,000 MVA. 15.0Δ/765Y...
Please answer the following question, box your answers, and show all work!! Thank you. 2 - The three-phase power and line-line ratings of the electric power system shown in Figure 2 are given below. T T2 V Line 2 Vm G M Figure 2 One-line diagram for problem 2 60 MVA 20 kV 50 MVA 20/200 kV 50 MVA 200/20 kV 200 kV 43.2 MVA 18 kV TI: T: Line: M: X=9% X=10% X=10% Z=120+j2002 X=8% a) Draw an impedance...