Concept explainers
The three-phase source line-to-neutral voltages are given by
Is the source balanced?
(a) Yes
(b) No
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Chapter 2 Solutions
MindTap Engineering, 1 term (6 months) Printed Access Card for Glover/Overbye/Sarma's Power System Analysis and Design, 6th
- A parallel connection of a RL branch with a C branch is connected across a 100V AC mains. At first R = 10 ohms, L = 20mH and frequency of 1000rad / s, the current measured is 2.2361A at 89.44 leading power factor. A) Determine the initial capacitance. B) However, a fault occurs on the capacitor branch making its capacitance 20% lower and a resistance of 5 ohms is detected. If this faulty circuit is rerun but at a frequency of 500 rad / s, determine the new current that will flow through the circuitarrow_forwardA parallel connection of a RL branch with a C branch is connected across a 100V AC mains. At first R = 10 ohms, L = 20mH and frequency of 1000rad / s, the current measured is 2.2361A at 89.44 leading power factor. A) Determine the initial capacitance. B) However, a fault occurs on the capacitor branch making its capacitance 20% lower and a resistance of 5 ohms is detected. If this faulty circuit is rerun but at a frequency of 500 rad / s, determine the new current that will flow through the circuit.arrow_forwardTwo power system areas operating at a nominal frequency of 60 Hz are connected with a tie line, and have the following characteristics: Area 1: R1 = 0.02 pu and D1 = 1 pu on a base of 1200 MVA Area 2: R2 = 0.03 pu and D2 = 0.8 pu on a base of 700 MVA The power flow direction on the tie line is from Area 1 to Area 2. Using a common base of 1000 MVA, what is the change in tie flow (in MW) for a load increase of 200 MW in Area 1? Select one: a.-56.16 MW O b. None of these O c.-143.84 MW O d.-38.02 MW <arrow_forward
- Two power system areas operating at a nominal frequency of 60 Hz are connected with a tie line, and have the following characteristics: Area 1: R1 = 0.01 pu and D1 = 0.8 pu on a base of 1200 MVA Area 2: R2 = 0.02 pu and D2 = 1 pu on a base of 600 MVA The power flow direction on the tie line is from Area 1 to Area 2. Using a common base of 1000 MVA, what is the change in prime mover power (in MW) in Area 2 (APmech2) for a load increase of 125 MW in Area 1?arrow_forwardTwo power system areas operating at a nominal frequency of 60 Hz are connected with a tie line, and have the following characteristics: Area 1: R1 = 0.01 pu and D1 = 0.8 pu on a base of 1200 MVA Area 2: R2 = 0.02 pu and D2 = 1 pu on a base of 600 MVA The power flow direction on the tie line is from Area 1 to Area 2. Using a common base of 1000 MVA, what is the change in prime mover power (in MW) in Area 2 (APmech2) for a load increase of 125 MW in Area 1? Select one: O a. 51.67 MW O b. None of these c. 24.74 MW O d.204.24 MWarrow_forwardIn a balanced system, the phasor sum of the line-to-line voltages and the phasor sum of the line-to-neutral voltages are always equal to zero. (a) False (b) Truearrow_forward
- Three single-phase transformers, each rated 10MVA,66.4/12.5kV,60Hz, with an equivalent series reactance of 0.1 per unit divided equally between primary and secondary, are connected in a three-phase bank. The high-voltage windings are V-connected and their terminals are directly connected to a 115-kV three-phase bus. The secondary terminals are all shorted together. Find the currents entering the high-voltage terminals and leaving the low-voltage terminals if the low-voltage windings are (a) Y-connected and (b) - connected.arrow_forwardA single-phase source has a terminal voltage V=1200volts and a currentI=1530, which leaves the positive terminal of the source. Determine the real and reactive power and state whether the source is delivering or absorbing each.arrow_forwardDoes an open- operation, the kVA rating compared to that of the original thr-phase bank is (a) 2/3 (b) 58 (c) 1arrow_forward
- A single-phase, 120V(rms),60Hz source supplies power to a series R-L circuit consisting of R=10 and L=40mH. (a) Determine the power factor of the circuit and state whether it is lagging or leading. (b) Determine the real and reactive power absorbed by the load. (c) Calculate the peak magnetic energy Wint stored in the inductor by using the expression Wint=L(Irms)2 and check whether the reactive power Q=Wint is satisfied. (Note: The instantaneous magnetic energy storage fluctuates between zero and the peak energy. This energy must be sent twice each cycle to the load from the source by means of reactive power flows.)arrow_forwardX₂=0.1 1 XL +03 Soto X₁ = 0.2 X = 0.1 X = 0.1 Above is the one-line diagram of a simple power system. Each generator is represented by an emf behind the subtransient reactance. All impedances are expressed in per unit on a common base. All resistances and shunt capacitance are neglected. The generators are operating on no load at their rated voltage with their emfs in phase. A symmetrical fault occurs at bus 1 through a fault impedance Z, =j0.08 per unit. a) Using Thevenin's Theorem, determine the impedance to the point of fault and the fault current in per unit. b) Find the bus voltages and line currents during the fault. 2 O otoarrow_forwardA workshop from a 231/400 V transformer center with a 3-phase and four-conductor underground cablefed. The resistance of the phase conductors is 0.035 ohms and the resistance of the neutral conductors is 0.05 ohms.25 kVA at 0.8 reverse power factor from R phase of the supply line, 0.8 forward power factor from S phase 15Fully ohmic loads of 10 kVA are drawn from kVA and T phases.(a) Find the currents flowing through the phase conductors and neutral conductors.(b) Voltage drops between the transformer substation and the workshop and at the load terminals.calculate the voltages(c) Plot the supply line currents and phase voltages phasorally.arrow_forward
- Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage Learning