Why the armature winding is always connected in star and the neutral is connected to ground?
1. The neutral grounding system helps to balance the flow of current in each phase. When a fault occurs the excessive fault current goes to the ground through the neutral grounding system. So as the STAR connection provides a neutral point we prefer STAR connection for the alternator armature winding.
What is the advantage of star connected 3 phase supply?
Transformers for high voltage operation with the star connections has the advantage of reducing the voltage on an individual transformer, reducing the number of turns required and an increase in the size of the conductors, making the coil windings easier and cheaper to insulate than delta transformers.
What is 3 phase Star Connection?
In the Star Connection, the similar ends (either start or finish) of the three windings are connected to a common point called star or neutral point. The three-line conductors run from the remaining three free terminals called line conductors.
Why is the stator winding always connected in Wye?
The stator winding of an alternator is generally connected in star so as to obtain neutral which is properly earthed at the generating station. At the sub-stations, the neutral point of the star-connected winding of transformer is also earthed. Thus neutral completes its path through the earth.
What is the difference between Star and Delta Connection?
Star and Delta Connections are the two types of connections in a 3 – phase circuits. A Star Connection is a 4 – wire system and a Delta Connection is a 3 – wire system. Hence, most of the power generated and distributed is actually a 3 – phase power (but majority of households will receive a single phase supply).
Why alternator are star connected?
Alternators are connected primarily in star to achieve the following motives: Lesser stress on insulation and Copper saving: Voltage per phase is less for a given line voltage which reduces insulation requirement and this also reduces the number of turns hence copper is also saved.
What is advantage of star connection?
Advantages of star connections: Each phase is a separate circuit. Dual voltage applications. Star connection can distribute the load evenly. Star connection alternator requires lesser insulation.
What is the advantage of star connection?
Answer: Transformers for high voltage operation with the star connections has the advantage of reducing the voltage on an individual transformer, reducing the number of turns required and an increase in the size of the conductors, making the coil windings easier and cheaper to insulate than delta transformers.
What motor has the starting winding and capacitor connected in series at all times?
Single-phase induction motors are not self-starting without an auxiliary stator winding driven by an out of phase current of near 90°. Once started the auxiliary winding is optional. The auxiliary winding of a permanent split capacitor motor has a capacitor in series with it during starting and running.
Which connection is more powerful Star or Delta and why?
Star connections are mainly required for the Power Transmission Network for longer distances, whereas in delta connection mainly in Distribution networks and is used for shorter distances. In star connection, each winding receives 230 volts and in delta connection, each winding receives 415 volts.
What happens when it is star connected or delta connected?
If the delta connected motor is connected in star, the voltage across the stator winding get reduced to 1/√3 (58%) of the voltage when the stator is connected in the delta. The torque delivering capacity of the motor is proportional to the square of the stator voltage.
Why is alternator armature winding always connected in Star, not in Delta?
It is a very important question which frequently asked in Interviews that Why Alternator Armature Winding always connected in STAR, not in DELTA? Today we discuss all reasons with the explanation. We know that in three phase system there are two types of connections, one is STAR connection and Another is DELTA connection.
How are the windings connected in a three phase alternator?
Rather than having six leads coming out of the three-phase alternator, the same leads from each phase may be connected together to form a wye (Y) connection, as shown in Figure 1, view B. It is called a wye connection because, without the neutral, the windings appear as the letter Y, in this case sideways or upside down.
Which is more efficient wye or Delta Connection for an alternator?
In the delta connection, line voltages are equal to phase voltages, but each line current is equal to 1.73 times the phase current. Both the wye and the delta connections are used in alternators. The majority of all alternators in use today are three-phase machines. They are much more efficient than either two-phase or single-phase alternators.
Why is a three phase stator called a Delta stator?
Because the windings form only one path for current flow between phases, the line and phase currents are the same (equal). A three-phase stator can also be connected so that the phases are connected end-to-end; it is now delta connected ( fig. 1, view C ). ( Delta because it looks like the Greek letter delta, ∆.)
It is a very important question which frequently asked in Interviews that Why Alternator Armature Winding always connected in STAR, not in DELTA? Today we discuss all reasons with the explanation. We know that in three phase system there are two types of connections, one is STAR connection and Another is DELTA connection.
Rather than having six leads coming out of the three-phase alternator, the same leads from each phase may be connected together to form a wye (Y) connection, as shown in Figure 1, view B. It is called a wye connection because, without the neutral, the windings appear as the letter Y, in this case sideways or upside down.
In the delta connection, line voltages are equal to phase voltages, but each line current is equal to 1.73 times the phase current. Both the wye and the delta connections are used in alternators. The majority of all alternators in use today are three-phase machines. They are much more efficient than either two-phase or single-phase alternators.
Why is phase winding connected in Star not in Delta?
2) The insulation requirement in STAR connection is less. Since phase voltage is 1/√3 times i.e. 57.7% (100 / √3 = 57.7%) of the line voltage, therefore the insulation requirement of phase winding reduces. This is a great advantage from economic point of view.