Electrical Mach...

A three-phase alternator has generated emf per phase of 230 V with 10% of third harmonic and 6% of fifth harmonic content. The rms line voltage for star connected is ______ (in V)

An alternator an open circuit generates 360 V at 60 Hz when the field current is 3.6 A. By neglecting the saturation, the open-circuit emf when the frequency is 40 Hz and field current is 2.4 A, is ______ (in V)

The following test results are obtained for a 3ϕ, 25 kV, 750 MVA, 60 Hz, 3600 rpm, star connected synchronous machine at rates speed.

A star connected synchronous generator is tested at the rated field current of 5 A. The open circuit voltage and the short circuit current are measured to be 540 V and 300 A respectively. If DC voltage of 10 V is applied across the terminals causes a current of 25 A, then the value of armature resistance is__ (in Ω)

The following test results are obtained from a 3-phase, 6000 kVA, 6600 V, star connected, 2-pole, 50-Hz turbo alternator.

With a field current of 125 A, the open circuit voltage is 8,000 V at the rated speed. With the same field current and rated speed, the short circuit current is 800 A. At the rated full load, the resistance drop is 3 percent.

A 3-phase 16-pole alternator has a star connected winding with 144 slots and 10 conductors per slot. The flux per pole is 0.03 Wb, sinusoidally distributed and the speed is 375 rpm. The line to line emf is _______ (in V)

A 3000 kVA, 3 – phase, star connected 6600 volt, 8-pole, 50 Hz alternator has a synchronous reactance of 20% and is running in parallel with infinite bus. The Synchronizing torque per mechanical degree of phase displacement at no load is ________ (in kN-m)

Two 600 kVA alternators operate in parallel to supply the following loads.

(i) 300 kW at 0.8 pf lagging

(ii) 150 kW at 0.6 pf lagging.

A synchronous generator has its effective internal impedance Z_s = 10 Ω and resistance r_a = 1 Ω. Its generated voltage E_f and terminal voltage V_t are both 500 V. The maximum power output is___ (in kW)