What are the condition for parallel operation of alternator?

What are the condition for parallel operation of alternator?

The phase sequence of the busbar voltages and the incoming machine voltage must be same. The busbar voltages and the incoming machine terminal voltage must be in phase. The terminal voltage of the incoming machine and the alternator which is to be connected in parallel or with the Busbar voltage should be equal.

What happens to the power factor of an alternator operating in parallel with other alternators if its excitation is increased above the normal value of excitation?

If the excitation of an alternator operating in parallel with other alternators is increased above its normal value of excitation, its power factor changes in the lagging direction and its current output increases with no appreciable change in its kW load.

Why parallel operation of the alternators is needed in our power system?

Alternators are operated in parallel for the following reasons: Several alternators can supply a bigger load than a single alternator. Parallel operation of the alternator, reduces the operating cost and the cost of energy generation. It ensures the greater security of supply and enables overall economic generation.

What are the conditions of parallel operation of alternators also state advantages of the parallel operation?

Parallel generators provide the maximum output when the power demand peaks and minimum output when the load necessities are low. Hence, parallel generators increase the reliability of power systems and make them more efficient.

How does excitation affect power factor?

A change in the excitation, thus, affects only the power factor of its output. This reduces the terminal voltage slightly, so let the excitation of the first alternator be increased so as to bring the terminal voltage back to its original value.

What are the advantages of parallel operation of transformers?

The advantages of parallel operation of transformers are:Increased reliability and maximized electrical power system availability. This is because it is not necessary to disconnect the whole system if fault occurs with one of the transformers.

When two alternator are running in exact synchronism the synchronising power will be?

When two alternators are in exact synchronism, the alternator will run on synchronism. A synchronizing torque will be developed if any of the alternators drops out of synchronism and will bring it back to the synchronism.

Which type of rotor is suitable for low speed alternators?

The salient pole type of rotor is generally used for slow speed machines having large diameters and relatively small axial lengths. The poles, in this case, are made of thick laminated steel sections riveted together and attached to a rotor with the help of joint.

Why do alternators have to be connected in parallel?

Due to the synchronous speed of rotation of field poles, it is also known as synchronous generator. Here, we can discuss about parallel operation of alternator. When the AC power systems are interconnected for efficiency, the alternators should also have to be connected in parallel.

What are the two modes of an alternator?

Operation modes of Alternator or generator – Grid mode & Island mode. An alternator or generator generates power might be used to supply either two purpose. The first is to supply power directly to the load or to consumer. The second one is to supply power to the grid.

When does the alternator supply power to the consumer?

When the alternator supplies power to the load or consumer directly, the criteria of the load affects the alternator. We can not control the load (KW or MW) and power factor but the terminal voltage and frequency can be controlled. This is called ISLAND mode.

What is the relation between frequency and power factor?

Ratio of active power to the apparent power is the power factor. The common component between frequency and power factor is active power. If active power generation increases, frequency increases, according to the ratio, the power factor also increases. This is the relation between frequency and power factor.