when a secondary bus is fed from many transformers connected in parallel, what kind of secondary...
19. Three single-phase transformers are connected in A - A. Each of these transformers has a secondary phase current of 10 A. The value of the secondary line current is 19. Three single-phase transformers are connected in A - A. Each of these transformers has a secondary phase current of 10 A. The value of the secondary line current is
Two 3-phase transformers are proposed to be connected in parallel to serve a large load. Transformer 1 is wye-delta, and Transformer 2 is wye-wye. Which of the following statements is most correct? (A) The transformers should not be paralleled. (B) The transformers may be. paralleled if the neutral of Transformer 2 secondary is unconnected and the turns ratio of Transformer 2 is 1.732 times the turns ratio of Transformer 1. (C) The transformers may be paralleled if the neutral of...
Problem #4-The primaries of two ideal 240/120 v, 60 Hz single phase transformers are connected in series and the combination is fed from a 480 v supply. The secondary of one transformer is connected to a resistance of 10 ohms and the secondary of the other to a resistance of 20 ohms. a-Calculate the currents in the two resistors. b-How does the 480 v divide between the primaries of the two transformers?
Problem #2 An industrial system bus is fed from an infinite bus thru a 150 MVA, 115kV/38kV, X=5% substation connected to a 75 MVA, 38kV/13.8kV, X-6.5% substation. A 25 MW, 13.8 kV, pf=.85, 3-phase, x=16% diesel generator is also connected to the industrial system bus. Several feeders are connected to the 38kV bus. If a fault occurs in one of such feeders, plot sag voltage at the 13.8kV bus vs. distance to fault with and without the generator contribution. The...
10. In order to meet an emergency, three single-phase transformers with 12.4707.200 Vrms are connected in A-Y to form a three-płuase transformer wluch is fed by a 12,470-V transmission line. If the transformer supplies 60 MVA to a lood, find (a) the tum ratio for each transformer, (b) the currents in the primary and secondary windings of the transformer, (c) the incoming and outgoing transmission line cuarents
A 100MVA synchronous generator is connected to a 25kV infinite bus through two parallel transmission lines. The synchronous reactance of the generator is 2.5Ω. Each transmission line has inductive reactance of 2Ω and 0.2Ω resistance. The generator delivers 90MVA to the infinite bus at 0.8 power factor lagging. For the above conditions, calculate: a. The terminal voltage of the generator b. The equivalent field voltage and power angle c. The real power output at the generator terminals d. The reactive...
Qustion 2.120 marks) a) Figure I below shows a system with plant-I and plant-2 connected to bus-1 and bus-2 respectively. There are two loads and 3 branches. The bus-I is the reference bus with 1.040° pu voltage. Base MVA is 100 If the branch currents and branch impedance values are as follows -2.5-j0.50pu -2-j040 pu I 1.5-j0.3 pu Calculate: 7-0.05+j0.20 pu -0.02+j0.08 pu Z 0.025+j0.10 pu i. Current distribution factors (4 marks) ii. Power factor angles at bus 1 and...
Ring Mesh Star Fully Connected Line Tree Bus When a message is to be sent from Node A to Node B and one of the links between A and B goes down true Ofalse - in a Ring network, the message may still be sent true Ofalse - in a Tree network, the message may still be sent true false - in a Fully Connected network, the message may still be sent true Ofalse - in a Bus network, the...
1. In order to meet an emergency, three single-phase transformers with 12.470/7.200 V are connected in Delta-Wye to form a three-phase transformer which is fed by a 12.470 V transmission line. If the transformer supplies 60 MVA to a load, calculate: (3 marks) a. The turns ratio for each transformer b. The currents in the primary and secondary windings of the transformer c. The primary and secondary transmission line currents 2. A Wye-Delta transformer is connected to a 66 kV...
5.3 A 13.8 kV, three-phase bus is supplied from a solidly grounded system with an effective reactance of 0.4. A 5.4 MVA capacitor bank is connected to the bus. During switching operation to disconnect the capacitor from the bus, the switch reignites, the reignition occurring when the voltage across the switch is 18 kV. What wil be the peak value of the reignition current? What voltage will be left trapped on the capacitor if this reignition current is interrupted? PROBLEMS...