Concept explainers
Three identical impedances
Trending nowThis is a popular solution!
Chapter 2 Solutions
Power System Analysis and Design (MindTap Course List)
- There is an installation with two identical three-phase motors, 50 HP each and a power factor of 0.9 behind. When connecting a pure reactive element in parallel, the reactive power at the installation input is 50 kVARS, with a lagging power factor. We can say that: a) A capacitor bank was connected and the pf improved. b) A bank of inductors was connected and the pf improved. c) A capacitor bank was connected and the pf deteriorated. d) A bank of inductors was connected and the pf deteriorated. e) None of the above.arrow_forwardThree Impedances each of (14 – j18)N are connected in mesh across a three-phase 415V ac supply. Determine the phase current, line current, active power, reactive power drawn from supply. Also draw the Phasor diagram for the mesh connection and marks the Line current ,phase current line voltage and phase angle between phase current and pahse voltage. phase current (Ip) Line current real power reactive powerarrow_forwardTwo impedances Zi and Zz are connected in parallel across a 230 V, 50 Hz supply. The impedance, Zi consists of a resistance of 14 Q and an inductance of 16 mH. The impedance, Z, consists of a resistance of 18 2 and an inductance of 32 mH. Calculate the branch currents, line current and total power factor. Draw the phasor diagram showing the voltage and currents. Page 14 2 16 mH 18 2 32 mH 0000 230 V, 50 Hz Figure 2arrow_forward
- A load of 240 +j 120 is connected to a source of 240 V with a phase angle of 300, through a transmission line with an inductive reactance of 60 ohms. A Capacitor bank of a capacitive reactance of 120 ohms is connected in parallel to the load. Total reactive power supplied by the source to the line is: O A. None of choices are correct O B. 1440 vars O C. 0 vars O D. 480 vars O E. 960 varsarrow_forwardThe impedance Z1 = 6+j8, Z2 = 8 -j6 and Z3 = 10+j0 ohms measured at 50Hz from three branches of a parallel circuit. This circuit is fed from a 100-volt 50-Hz supply. A purely reactive (inductive or capacitive) circuit is added as the fourth parallel branch to the above three-branched parallel circuit so as to draw minimum current from the source. Determine the value of L or C to be used in the fourth branch and also find the minimum current.arrow_forwardA balanced load is connected in star across a 3 phasec415V 50Hz supply. The load consists of a coil of resistance 25 ohms and inducrance 0.5 henry in paeallel with a purw resistance of 28 ohms and a pure capaciror of 60microfarads capacitance ,in each branch. Calculate a. The line currents The answer has to be 9.3Aarrow_forward
- A balanced three-phase Delta connected voltage source supplies Delta connected three-phase symmetrical load through a three-phase line at 50 Hz as shown in the figure below. Please, answer the following using ZL=0.4+j 0.8 N and Zab = Zbc = Zca=10.3+j 14.1 N. A I a Zz Z. ca I 400 20° v +1 400Z-120° v Ic SOURCE LINÉ LOAD Part F: Calculate the reactive power of the three-phase Delta load in terms of VAr. 4002-240° varrow_forward1. What is the main direct cause of reactive power in AC system? A. Resistance of transmission lines B. Inductance and capacitance in the loads C. Ideal transformer connected in the system D. Power produced by generator 2. "Reactive power in a system is dissipated generally as thermal energy?" A. TRUE B. FALSE 3. Which of the following statements are correct for three phase circuit: A. Sum of all the three phase currents is zero in unbalanced network B. Total power transfer to load is constant with time C. Neutral conductor is same size in terms of material used as in single phase conductors D. Net apparent power consumed is equal to real powerarrow_forwarda. Y-Connected b. В 100kW Source 0.9 LAG 80KVA 0.8 LAG Figure 1 80kW 0.85 LAGarrow_forward
- For the reactance network shown in Figure 2, find element Y33 of its bus admittance matrix. Below are the given reactances: JA = 0.8 jB = 0.7 jC = 0.3 jD = 0.6 jF = 3 jG = 3 2) j B jc jD jA 8 1.2 1 28/0Oarrow_forward2. For the circuit shown in Figure 2 (a) Calculate the total average and reactive power delivered to each impedance in the circuit. (b) Calculate the average and reactive powers associated with each source in the circuit. (c) Verify that the average power delivered equals the average power absorbed and the magnetizing reactive power equals the magnetizing reactive power absorbed. Vị j40 20 j6n V, V- 401 -j120 V, = 150 0° V V1 = (78 – j104) V 1 =(-26 – j52)A I = (-2+ j6) A V2 = (72 + j104) V V3 = (150 – j130) V h= (-24 – j58) Aarrow_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