A 1MVA, 11 KV, three phase wye-connected synchronous generator has a synchronous reactance of 5 ohms and a negligible reactance per phase. At a certain field current the generator delivers rated load at 0.9 lagging power factor at 11 KV. For the same excitation, what is the terminal voltage at 0.9 leading power factor full-load?

Three identical steam-turbine generators G1, G2, and G3 are operating in parallel. Each generator is: 7.2 KV, 21 MVA, 50 Hz, 0.85 PF lagging, 4-poles, Y-connected, with synchronous reactance of 2 Q and an armature resistance of 0.05 Q. Each of generators G1 , G2, and G3 has a characteristic power-frequency slope of 5.2 MW/Hz , 4.5 MW/Hz, and 4.9 MW/Hz, respectively The no-load frequency of each generator is set to 52.4 Hz. The load increases with no changes in the settings of the no-load frequencies, until a generator reaches its maximum rated power first. At what system frequency does this limit occur? Select one: O a. fsys = 48.97 Hz O b. fsys = 48.25 Hz c. fsys = 49.22 Hz O d. None

In a certain sub-station, there are 5 d.c. shunt generators in parallel, ench having an armature resistance of 0.1 0, running at the same speed and excited to give equal inducnd emfs Each generator supplies an equal share of a total load of 250 kW at a terminal voltage of 500 V into a load of fixed resistance. If the field current of one generator is raised by 4%, the others remaining unchanged, calculate the power output of each machine and their terminal voltages under these conditions Assume that the speeds remain constant and flux is proportional to field current

The amplitude of the sinusoidal symmetrical ac component of the three-phase short-circuit current of an unloaded synchronous machine decreases from a high initial value to a lower steady-state value, going periods through the stages of __________ and ________ periods.

A three-phase Y-connected synchronous generator is rated 120 MVA, 13.2 kV, 0.8 PF lagging, and 60 Hz. Its synchronous reactance is 0.9 Q, and its resistance may be ignored. (a) What is its voltage regulation? (b) What would the voltage and apparent power rating of this generator be if it were operated at 50 Hz with the same armature and field losses as it had at 60 Hz? (c) What would the voltage regulation of the generator be at 50 Hz?

i need the answer as fast as possible please.

A 1500 kVA, star-connected, 2300 V, 3-phase, salient-pole syn- chronous generator has reactances X4= 1.95 Q and X, = 1.40 2 per phase. All losses may be neglected. Find the excitation voltage for operation at rated kVA and power factor of 0.85 lagging.

2. Clear and complete solution.

A 60 MVA, 69.3 KV, three-phase synchronous generator has a synchronous reactance Xs = 15 ohm/phase. The generator is supplying its rated power (i.e. 60 MVA) to an infinite bus at 0.8 power factor lagging. Determine: a) The armature current Ia. b) The generator emf per phase (E). c) The power angle. d) The maximum power (P) that the generator can supply. Xs = j 150 la Vline = 69.3 KV

A 50 Hz three-phase Y-connected 4 pole synchronous generator is rated at 15 kVA, 400 V (line-to-line). The synchronous reactance Xs per phase is 20. The no-load (open circuit, line-to line) teminal voltage follows the magnetisation curve shown in Figure Q2a below. 500 E 450 400 350 300 250 200 150 100 50 0.5 1 1.5 2.5 Field current (A) Figure Q2a: Magnetisation curve for rotor of a synchronous generator. (i) Determine the rated speed. (ii) What is the field current required at full-load operation at 0.8 lagging pf. (iii) Draw the phasor diagram for the mode of operation described in (ii) above. (iv) If the field current is set to 1.5 A, calculate the total active power that is delivered by the machine when it is operating as a generator connected to a 400 V (line-to- line) infinite bus and making a torque angle of 5°. Open-circuit terminal voltage (V)