A 3-phase, 4-wire distributor supplies a balanced voltage of 400/230 V to a load consisting of 8 A at p.f. 0-7 lagging for R-phase, 10 A at p.f. 0-8 leading for Y phase and 12 A at unity p.f. for B phase. The resistance of each line conductor is 0.4 2. The reactance of neutral is 0.2 2. Calculate the neutral current, the suppl voltage for R phase and draw the phasor diagram. The phase sequence is RYB. VR Phasor diagram

A 3-phase, 4-wire distributor supplies a balanced voltage of 400/230 V to a load consisting of 8 A at p.f. 0-7 lagging for R-phase, 10 A at p.f. 0-8 leading for Y phase and 12 A at unity p.f. for B phase. The resistance of each line conductor is 0.4 2. The reactance of neutral is 0.2 2. Calculate the neutral current, the suppl voltage for R phase and draw the phasor diagram. The phase sequence is RYB. VR Phasor diagram

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 3.33P: Consider the three single-phase two-winding transformers shown in Figure 3.37. The high-voltage...

See similar textbooks

Similar questions

Consider a single-phase electric system shown in Figure 3.33. Transformers are rated as follows: XY15MVA,13.8/138kV, leakage reactance 10 YZ15MVA,138/69kV, leakage reactance 8 With the base in circuit Y chosen as 15MVA,138kV determine the per-unit impedance of the 500 resistive load in circuit Z, referred to circuits Z, Y, and X. Neglecting magnetizing currents, transformer resistances, and line impedances, draw the impedance diagram in per unit.
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.
GMR calculate
11
A 500 kVA, 1100 V, 50 hz, wye-connected 3-phasehas armature resistance of 0.1 02/phase and synchronous reactance/phase of 1.502. (i) What is voltage regulation if the load pf is 0.9 lagging ? (ii) what is voltage regulation if the load pf is 0.8 leading?
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
Consider the system shown in Figure 1. Assume the load voltage (VL) is 4720 V and the load consumption is 80 kVA at 0.85 lagging power factor. The line impedance (Zline) is 4.6+j8.5 2. The parameters of the 14,400/4800-V single-phase transformer referred to the secondary are: Req=0.95 , Xeq = 1.74 , Re = 48.5 kn, and Xm = 31.1 k. vp avs 4.6 +19.52 Zline Vs ~ P a:1 ele rmis alf Reais leee V₂ zí S Figure 1: System for Q1 I wad a) Find the current of the load. b) Find the primary and secondary voltages of the ideal transformer. nuomo I un cucc + Bline Xeq,s 1 V₂² 95, 74-32 1. VL 4720 Ponerlosture -> Pont IL = V₂ -V₂ Zine
i) Calculate V1 and V2 for the voltage across the string insulator having phase voltage of 33kV for transmission line using details tabulated in the Table 3(a). Table 3(a) Type of Insulator Shunt Capacitance between each unit 0.1 C String to junction Self -Capacitance of each insulator ii) With the help of a suitable schematic diagram and necessary theoretical explanation, illustrate how to improve the efficiency of the suspension insulator.
The one line diagram of power system is shown in Figure Q.1. Use a commonbase MVA of 100 MVA and base voltage of 230 kV at the transmission line. Findthe p.u values to be used for the transformer and generator reactances.
A 33 kV single core cable has a conductor diameter of 1 cm and a sheath of inside diameter 4 cm. Find the maximum and minimum stress in the insulation.
5. A two wire DC ring main distributor ABCDEA is fed at point C with 230V supply. The resistances of go and retum conductors of each section AB, BC, CD, DE and AE are 0.1 2 each. The main supplies the loads of 20A at A, 10A at B, 10A at D, 30A at E. Estimate: voltage at each load point i. minımum consumer voltage.
In developing per-unit equivalent circuits for three-phase transformers. under balanced three-phase operation. (i) A common Sbase is selected for both the H and X terminals. (ii) The ratio of the voltage bases Vbase/VbaseX is selected to be equal to the ratio of the rated line-to-line voltages VratedHLL/VratedXLL. (a) Only one of the above is true. (b) Neither is true. (C) Both statements are true.