A 30- kVA, 8000/230-V trans urmer has the iulint cient N, N on A 30- kVA, 8000/230-V trans urmer has the iulint cient N, N on
Q1: A 20-kVA 8000/480-V distribution transformer has the following resistances and reactances: Rp 322 X,-45 Ω R,-0.05 Ω X,-0.06 Ω The excitation branch impedances are given referred to the high-voltage side of the transformer. (a) Find the equivalent circuit of this transformer referred to the high-voltage side. (b) Assume that this transformer is supplying rated load (20kVA) at 480 V and 0.8 PF lagging. What is this transformer's input voltage? What is its voltage regulation? (c) What is the transformer's...
6. A 20 kVA. 60 Hz, 8000/277 V transformer has the following impedances referred to the high voltage side: Req-320, xe,-45Ω,R.-250kQ,Xm-30kQ. A) Calculate the voltage across rated load impedance with PF= 0.707 lagging when the transformer is connected to rated input voltage. B) Draw the phasor diagram showing the load voltage and current, voltage drop across the series impedance and voltage at the low voltage side of the ideal transformer, C) Calculate the efficiency of the transformer D) What adjustments...
Given: A 12.5 kV circuit has a load of 8000 kVA with a lagging power factor of 0.8. Required: How much capacitive reactive power is needed to correct the power factor to 0.92 lagging? Solution: Q= O kVAR's
2.3 (20 points) A separately-excited de motor is mechanically coupled to a three-phase, 4-pole, 30-kVA, 460-V, round-rotor synchronous generator. The de motor is connected to a constant 230-V de supply The ac generator is connected to a 460 V, fixed-voltage, fixed-frequency, three-phase supply. The synchronous reactance of the synchronous generator is 513 Ω/phase. The armature resistance of the de motor is 30 m2. The 4-pole de machine is rated 30 kW at 230 V. All unspecified losses are to be...
Electric Machinery Problem 2: [50 points] A 15-KVA, 230/2300-V transformer is considered. The following test data have been taken: | OC Test (on Primary) Voc = 230 V loc = 2.8 A Poc = 100 W SC Test (on Secondary) Vsc = 47 V Isc = 9.5 A Psc = 350 W (a) Find the equivalent circuit of this transformer referred to the high- voltage side. [10 points] (b) Find the equivalent circuit of this transformer referred to the low-...
P7.16 A 10-kVA three-phase VSI is supplied from a 230-V ac line through a si SIX- pulse diode rectifier. The inverter is designed for a unidirectional powee fer, from dc to ac. Assume the voltage safety margin of 40%, the cures, safety margin of 25%, and determine the minimum required voltage and cur- rent ratings of switches and diodes in the inverter. P7.16 A 10-kVA three-phase VSI is supplied from a 230-V ac line through a si SIX- pulse diode...
A 230 V, 1000 rpm, 30 A separately excited motor has armature resistance and inductance of 0.7 Ω and 50 mH respectively. Motor is controlled in regenerative braking by a chopper operating at 800 Hz from a dc source of 230 V. Assuming continuous conduction a) Calculate duty ratio of chopper for rated torque and the speed of 800 rpm. b) What will be the motor speed for duty ratio of 0.6 and rated motor torque? c) What will be...
3. The following measurements have been performed through the open-circuit test of a 15 kVA, 2300/230 V transformer: Voc 2300 V,loc 0.21 A, Poc 50 W, What parameters can be calculated through the open-circuit test of a transformer? Calculate the parameter values from the given data. (The equivalent circuit of a transformer is very similar to that of the induction motor shown above. The only differences are that there is no slip term's' and there is a resistance Rc representing...
Problem 1 A 60Hz transformer is rated 30 (kVA), 4000(V)/120(V). The open circuit test, with the high voltage side open, gives Po= 100 (W), loc = 1.1455 (A). The short circuit test, measured with the low voltage side shorted, gives Pse = 180 (W), Vse = 129.79 (V). a) Determine the equivalent circuit for the transformer (both open and short circuit) b) Calculate the circuit components. (Req, Xeq, Rc, Xm)
Rework problem 3.4 if the load connected to the 240-V secondary winding absorbs 110 kVA under short-term overload conditions at an 0.8 power factor leading and at 230 volts. Reference of problem 3.4 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 60kVA at 0.8 power factor lagging and is at 230 volts. Assuming an ideal transformer, calculate the following: a) primary...