Problem 1 The no-load curve VNL = f(!m) of a 4-pole, 2-hp, star-connected squirrel cage induction...

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Problem 1 The no-load curve VNL = f(!m) of a 4-pole, 2-hp, star-connected squirrel cage induction machine with rated values of: 220 V, 60 Hz, 1725 rpm, 6.1 A. 300.0 250.0 200.0 150.0 100.0 50.0 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 Phase Current (A) The excitation current of the machine was supplied from star-connected capacitors connected in parallel with the machine. Calculate: a) The minimum capacitance required for self-excitation of the machine at the synchronous speed? b) The capacitance required to obtain the rated terminal voltage at the synchronous speed? c) On the same no-load characteristics graph, plot the capacitance load-line for (a) and (b). Problem 2 Consider the induction generator given in Problem 1. Find the capacitance bank required when it is connected as delta and the generator and bank reactive powers and then draw the equivalent diagram showing the direction of the power flow for each of the following operating conditions: a) At no load condition at rated voltage. b) When it is supplying a three-phase Y-connected load with 4 A at 0.8 pf lagging at rated voltage. c) Redo (a) and (b) at a 200 V line to line. Line Voltage ( v) Problem 1 The no-load curve VNL = f(!m) of a 4-pole, 2-hp, star-connected squirrel cage induction machine with rated values of: 220 V, 60 Hz, 1725 rpm, 6.1 A. 300.0 250.0 200.0 150.0 100.0 50.0 0.0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 Phase Current (A) The excitation current of the machine was supplied from star-connected capacitors connected in parallel with the machine. Calculate: a) The minimum capacitance required for self-excitation of the machine at the synchronous speed? b) The capacitance required to obtain the rated terminal voltage at the synchronous speed? c) On the same no-load characteristics graph, plot the capacitance load-line for (a) and (b). Problem 2 Consider the induction generator given in Problem 1. Find the capacitance bank required when it is connected as delta and the generator and bank reactive powers and then draw the equivalent diagram showing the direction of the power flow for each of the following operating conditions: a) At no load condition at rated voltage. b) When it is supplying a three-phase Y-connected load with 4 A at 0.8 pf lagging at rated voltage. c) Redo (a) and (b) at a 200 V line to line. Line Voltage ( v)