Concept explainers
Videos
A Y-connected load bank with a three-phase rating of 500 kVA and 2300 V consists of three identical resistors of
Trending nowThis is a popular solution!
Chapter 8 Solutions
Power System Analysis and Design (MindTap Course List)
- 5. The figure below shows two star connected loads with three phase power. The voltage source is 120Z0°. The loads are Z₁ = 10 + j4 № and Z₂ = 2 +j3 №. The cables are negligible. Calculate: a) the line and phase current. b) the real power from the source. c) the reactive power of the circuit. Is V N Z₁ Z₁ Z₁ Z₂ Z₂ N N Z₂arrow_forwardThree single phase loads are connected to the 400 V, three phase lines, 60 Hz. Load 1 operating at 3 kVA, 0.8 power factor lagging and is connected at line "a" and "b", Load 2 is a 5 kW heater and is connected at line "b" and "c", Load 3 is 4.5 kW machine that operates at a power factor of 0.6 lagging and is connected at lines "c" and "a". a. What are the line currents Ia, Ib, and Ic in Amperes (in Polar form) b. What is the total power factor.arrow_forwardMatch the following Each load wilI be connected between two phase wires Choose... Power measured by two wattmeter method Choose... Each load will be connected between a Phase wire and Neutral wire only unbalanced Load Both Balanced and Unbalanced Load Current in the neutral wire is zero Star connection Junction Point where one end of all three phase loads joined together Delta Point Delta connection Only Balanced Load Series Connection Neutral pointarrow_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_forwardTwo balanced Y-connected loads, one drawing 10 kW at 0.8 power factor lagging and the other IS kW at 0.9 power factor leading, are connected in parallel and supplied by a balanced three-phase Y-connected, 480-V source. (a) Determine the source current. (b) If the load neutrals are connected to the source neutral by a zero-ohm neutral wire through an ammeter, what will the ammeter read?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
- Figure 3.32 shows the oneline diagram of a three-phase power system. By selecting a common base of 100 MVA and 22 kV on the generator side, draw an impedance diagram showing all impedances including the load impedance in per-unit. The data are given a follows: G:90MVA22kVx=0.18perunitT1:50MVA22/220kVx=0.10perunitT2:40MVA220/11kVx=0.06perunitT3:40MVA22/110kVx=0.064perunitT4:40MVA110/11kVx=0.08perunitM:66.5MVA10.45kVx=0.185perunit Lines I and 2 have series reactances of 48.4 and 65.43, respectively. At bus 4, the three-phase load absorbs 57 MVA at 10.45 kV and 0.6 power factor lagging.arrow_forwardWhen working with balanced three-phase circuits, per-phase analysis is commonly done after converting loads to Y loads, thereby solving only one phase of the circuit. (a)True (b)Falsearrow_forwardR 20 B Y R 20 400V, 60Hz B IR ZB = 55 < 0° 0 Figure 4: Star Unbalanced Load IR ZR IB ZY ZR = 30 < 0° 0 Fault Zy17 <0°02 = A balanced load with ZR = ZB Zy = ....<00 Q was supplied a three phase 50 Hz, 100 V between line (balanced source). A fault on phase 'B' causes an open circuit, which unbalanced the load as shown in Figure 4. Similarly, a fault on the load of phase 'Y' cause a short-circuit, which unbalanced the load as shown in Figure 5. Using complex notation determine and analyse the individual phase currents and the neutral current in both figure.arrow_forward
- A 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_forwardindow Help 2019-2020 sem I_a5ed088cade3f4... Q Search 99 Example 20 MVA 60 MVA 20 MVA 0.08 pu 0.1 pu 0.09 pu Find the short circuit current at G3 G1 G2 the fault in the point F for the 11.8 kV power system shown in figure. F.arrow_forwardThree unequal single-phase loads are connected across the lines of a balanced, 3-phase, 230 volts (line) circuit. The first load takes 106 A at 0.78 pf lagging and is connected across lines 1 & 2. The second load takes 142 A, at 0.82 pf lagging and is connected across 2 & 3. The third one takes a load of 28.4 kW at 0.77 pf lagging. Solve for the following a. The line currentsb. The equivalent wye connected impedance of the connectionc. The total complex power absorbed by the loadarrow_forward
Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage Learning