A 2850 hp, 4 kV induction motor is connected to the supply system through 2.5 MVA...
A 450 MVA, 26-kV generator is connected to a 345-kV power system through a 500MVA, 26-kV:345-kV transformer which can be represented by a series reactance of 95 m Ω when referred to its low-voltage terminals. The generator has a saturated synchronous reactance of 1.73 per unit and a rated-open- circuit-voltage field current of 2140 A. Under normal operating procedures, the generator is operated under automatic voltage regulation set to maintain its terminal voltage at 26 kV. In this problem you...
QUESTION 4. A single-line diagram of a power system is shown in Figure Q3 below, where negative and zero-sequence reactances are also given. The neutrals of the generator and A-Y transformers are solidly grounded. The motor neutral is grounded through a reactance X.=0.05 per unit on the motor base. Prefault voltage is VF1.05<Oº per unit whereas prefault load current is zero. Take A-Y transformer phase shifts into consideration. M Line tool X, - X2 - 200 100 MVA X =...
4.6. A 460-V, 75 kW, 4-pole, delta-connected, 60-Hz, three- phase induction motor has a full-load slip of 5 percent, an efficiency of 92 percent and a power-factor of 0.87 lagging at full-load. At start-up, the motor develops 1.9 times the full load developed torque but draws 7.5 times the rated current at the rated voltage. This motor is to be started with an auto- transformer reduced-voltage starter. Assume the stator resistance and the stator core loss to be negligible. Calculate...