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answerhappygod
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Over? Question 1: [12 Marks] ick the correct answer for the following statements .) The equation of the induced e.m.f (E) of a stand-alone synchronous generator was the form (a) E=kx flux * speed (b) E = k/flux / speed (c) E = kx flux / speed 2) When should two of the phases on the synchronous generator be swapped This needs to be done when the grid to which the generator is to be connected has a correct clockwise-rotating field With the bright lamp circuit, this only needs to happen if the lights do not light up in a cyclic sequence • As soon as the lights light up in a cyclic sequence it becomes essential to swap two of the phases 3) What happens if the generator is connected to the grid without being in synch with it? . Due to the fact that is a motor protection switch in the circuit anyway, there is nothing that can happen If the generator is connected to the grid without being in synch, then the sort of high currents associated with short-circuits start flowing, risking both people/equipment 4) What conditions need to be fulfilled before the generator is switched through to the grid? (More than one statement may be correct) The sequences of phases and the phase relationship must be the same at the generator and on the grid • The voltage on the grid and from the generator do not necessarily need to match before synchronization since they will do after synchronization anyway The voltage being generated by the generator and its frequency need to be exactly the same as what is on the grid The absolute magnitudes of the RMS values for the generator voltage and the voltage on the grid need to be the same F) What is the correct method to reverse rotation direction of induction motor? Interchange the terminals for the rotor winding Interchange any random two terminals of the stator winding Only interchange L2 & LI on the stator winding
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Over? Question 1: [12 Marks] ick the correct answer for the following statements .) The equation of the induced e.m.f (E) of a stand-alone synchronous generator was the form (a) E=kx flux * speed (b) E = k/flux / speed (c) E = kx flux / speed 2) When should two of the phases on the synchronous generator be swapped This needs to be done when the grid to which the generator is to be connected has a correct clockwise-rotating field With the bright lamp circuit, this only needs to happen if the lights do not light up in a cyclic sequence • As soon as the lights light up in a cyclic sequence it becomes essential to swap two of the phases 3) What happens if the generator is connected to the grid without being in synch with it? . Due to the fact that is a motor protection switch in the circuit anyway, there is nothing that can happen If the generator is connected to the grid without being in synch, then the sort of high currents associated with short-circuits start flowing, risking both people/equipment 4) What conditions need to be fulfilled before the generator is switched through to the grid? (More than one statement may be correct) The sequences of phases and the phase relationship must be the same at the generator and on the grid • The voltage on the grid and from the generator do not necessarily need to match before synchronization since they will do after synchronization anyway The voltage being generated by the generator and its frequency need to be exactly the same as what is on the grid The absolute magnitudes of the RMS values for the generator voltage and the voltage on the grid need to be the same F) What is the correct method to reverse rotation direction of induction motor? Interchange the terminals for the rotor winding Interchange any random two terminals of the stator winding Only interchange L2 & LI on the stator winding