3. Three single-phase, 10 kVA, 460/120 V, 60 Hz transformers are connected to form a three-phase 460/208 V transformer bank. The equivalent impedance of each transformer referred to HV side is 1.0 + j2.0 Ω. The transformer delivers 25 kW at 0.9 pf lagging at rated voltage. Answer the following questions: (a) Draw a schematic diagram showing the transformer connection. Draw three separate single-phase transformers and complete their primary and secondary connections. (b) Determine the magnitude of transformer primary and secondary winding phase currents.
3. Three single-phase, 10 kVA, 460/120 V, 60 Hz transformers are connected to form a three-phase...
A single-phase 10 kVA, 460/120 V, 60 Hz, transformer has an efficiency of 96% when it delivers 9 kW at 0.9 pf lagging. The transformer is connected as an autotransformer to supply load to a 460 V circuit from a 580 V source. Show the autotransformer connection Determine kVA rating of the autotransformer Determine the efficiency of the autotransformer at full-load with 0.9 pf lagging
Ideal, single-phase two-winding transformer A single-phase two-winding transformer is rated 20 kVA, 480/120 V, 60 Hz A source connected to the 480-V winding supplies an impedance load con- nected to the 120-V winding. The load absorbs 15 kVA at 0.8 p.f. lagging Ideal, single-phase two-winding transformer A single-phase two-winding transformer is rated 20 kVA, 480/120 V, 60 Hz A source connected to the 480-V winding supplies an impedance load con- nected to the 120-V winding. The load absorbs 15 kVA...
Three single-phase transformers rated at 250 kVA, 7200 V/600 V, 60 Hz, are connected in wye- delta on a 12.47 kv, 3-phase line. If the load is 450 kVA, calculate: a. The currents in the incoming and outgoing transmission lines b. The currents in the primary and secondary windings 1. sratod t 200 w 3o0 v/6oO V 60 Hz are used to raise the Three single-phase transformers rated at 250 kVA, 7200 V/600 V, 60 Hz, are connected in wye-...
2. Three single-phase transformers rated at 300 KVA, 7200 V/600 V, 60 Hz, are used to raise the voltage of a 3-phase, 600 V line to 7.2 kv. a. How must they be connected? b. Calculate the line currents for a load of 750 kVA. C. Calculate the corresponding primary and secondary currents.
A tie breaker is accidently closed that parallels three single phase transformers each rated 500 kVA connected delta primary wye secondary, with a three phase 1500 kVA transformer connected delta-delta. The equivalent impedance of the delta transformer is 0.056 at an angle of 58o. The equivalent impedance of the wye transformers is 0.022 at an angle of 58o. Both transformer have 12.47kV to 480V. All feeder breakers are open. Calculate the magnitude of the current circulating in each transformer secondary,...
A single-phase 100-kVA, 2400/240-volt, 60-Hz distribution transformer is used as a step-down transformer. The load, which is connected to the 240-volt secondary winding, absorbs 80 kVA at 0.8 power factor lagging and is at 230 volts. Assuming an ideal transformer, calculate the following: a) primary voltage. b) load impedance. c) load impedance referred to the primary. d) the real and reactive power supplied to the primary winding
A three-phase, 5 kVA, 208 V, four-pole, 60 Hz, wye-connected synchronous machine has negligible stator winding resistance and a synchronous reactance of 8 Wper phase. It is operated in parallel with a three-phase, 208 V, 60 Hz power supply.Determine the excitation voltage and the power angle when the machine is delivering rated kVA at 0.8 pf lagging. Draw the phasor diagram
A three-phase Yy0 connected transformer has a nominal rating of 250 kVA and a voltage ratio 15:0.4 kV. After conducting the short-circuit test, where the secondary winding is short-circuited, it is found that the primary series resistance is 0.08 pu and the primary series impedance magnitude is 0.1pu. The effect of the parallel branch in the transformer’s equivalent circuit may be neglected. Explain what information ‘Yy0’ gives about the transformer. Draw the per-phase equivalent circuit of the transformer during the...
Q No.1: A 14,000/130-V, three-phase, ∆-Y transformer bank consists of three identical 100-kVA, 83l4/130-V transformers. It is supplied with power directly from a large constant voltage bus. In the short-circuit test, the recorded values on the high-voltage side for one of these transformers are Vsc = 510V, Isc = 12.6 A, Psc = 3000 W (a) If this bank delivers a rated load at 0.8 PF lagging and rated Voltage, what is the line-to-line voltage on the primary of the...
please solve the question in pu sysyem !!!! Solvein pu sysvem 2-10. A 13,800/480 V three-phase Y-A-connected transformer bank consists of three identical 100-kVA 967/480-V transformers. I is supplied with power directly from a large constant-voltage bus. In the short-circuit test, the recorded values on the high-voltage side for one of these transformers are Isc 12.6 A Pc3300 w (a) If this bank delivers a rated load at 0.85 PF lagging and rated voltage, what is the line-to-line voltage on...