The series motor has poor speed regulation. When the load speed of the machine increases, the DC shunt motor keeps its constant speed from no load to full load. The dc series motor’s Torque drops sharply when the speed increases.
What is the main disadvantage of series wound generator?
The main disadvantage of series generators, Output voltage varies as the load varies The e. mf induced in the armature winding is constant with . time Inter pole winding is connected in series with main poles of d.c machine Series motor maintains a more constant speed under varying load.
What is the advantage and disadvantage of generator?
AC is very easy and efficient to transmit over a long distance rather than DC. The design of the AC generator is fairly simpler than DC generator type. No need for matching a voltage. Cost of ownership is lower.
What are the disadvantages of DC generators?
Like other machines, DC generators have some disadvantages, such as:
- DC generators can’t be applied to a transformer.
- DC generators have low efficiency because there are copper losses, eddy current losses, hysteresis losses, and mechanical losses.
- A voltage drop over long distances would occur.
What are the disadvantages of a shunt?
It has poor efficiency for large load currents. It has high output impedance. The output DC voltage is not absolutely constant because both VBB and VZ voltages decrease with increase in room temperature.
What are advantages and disadvantages of a series motor?
The series motor has the highest starting torque for a given power rating. When the motor is overloaded, the speed drops and the torque increases. While delivering high torque during an overload, the series motor draws less current and power from the source compared to a shunt or compound DC motor.
What is series generator?
When the field winding of a DC generator is connected in series with the armature, the generator is called a series-wound generator (Figure 10).A series generator has poor voltage regulation, and, as a result, series generators are not used for fluctuating loads.
What are the disadvantages of electric generator?
- Requires very large space to collect sufficient energy.
- Lower efficiency in the generation of electricity.
- Intensity of sunlight is dependent on seasonal changes, climate and latitude of the region.
What are the disadvantages of alternating current?
The disadvantage of Alternating Current
- It is less dangerous than DC but more attractive.
- Working with AC is much more dangerous than high voltage DC.
- AC can not be used for electrofishing, electroplating, etc.
- Cannot charge batteries directly from AC.
- Fatal accidents can happen with the slightest disregard.
What are the advantages and disadvantages of alternating current?
(i) The generation of AC is cheaper than that of DC. (ii) When AC is supplied at higher voltages, the transmission losses are small compared to DC transmission. (iii) AC can easily be converted into DC with the help of rectifiers.
What are the advantages and disadvantages of separately excited DC generator?
Separately excited DC generators have many advantages over self-excited DC generators. It can operate in stable condition with any field excitation and gives wide range of output voltage. The main disadvantage of these kinds of generators is that it is very expensive of providing a separate excitation source.
What are the disadvantages of DC motor?
Disadvantages of DC motors
- High initial cost.
- Increased operation and maintenance cost due to the presence of commutator and brush gear.
- Cannot operate in explosive and hazard conditions due to sparking occur at brush (risk in commutation failure)
What are the advantages of compound generators?
Advantages of Compound DC Generator
In compound generator, the armature voltage decreases automatically, when load current increases, due to which magnetic field produced by shunt winding decreases. But the same increase in load current flows through the series winding causes an increase in the magnetic field.
What is the main disadvantages of a series motor?
The series motor has poor speed regulation. When the load speed of the machine increases, the DC shunt motor keeps its constant speed from no load to full load. The dc series motor’s Torque drops sharply when the speed increases.
What are the demerits of a series voltage regulator?
Disadvantages:
- It has not so good voltage regulation for large loads currents.
- The series pass transistor should be power transistor and it has to be mounted on a suitable heat sink. This makes the series regulator circuit bulky and heavy.
- The output voltage cannot be changed easily as no such means is provided.
What is the main disadvantage of a shunt motor?
As the load changes, a shunt wound motor runs at a predictable speed. If variable speed is desired, constant speed can be a disadvantage. The lifetime of the motor is usually not improved by brushes.
What is the advantage of a compound motor over a series motor?
Compound DC motor provides high starting torque and also provides good speed regulation. However, it is a compromise between both types of motors, which means it has good starting torque as compared to series DC motor but slightly lesser than shunt DC motor.
What are the characteristics of a series motor?
Series Motors
A characteristic of series motors is the motor develops a large amount of starting torque. However, speed varies widely between no load and full load. Series motors cannot be used where a constant speed is required under varying loads.
What are the advantages and disadvantages of speed control by armature voltage control method?
field control:
- Higher initial costs: The armature control method is often more expensive than the field control method.
- Low energy efficiency: One reason why armature control is most commonly used for shorter lengths of time is that speed variation tends to waste large amounts of power.
Where is series generator used?
Applications of series generator: Used for supplying field excitation current in DC locomotives for regenerative breaking. Used as boosters to compensate the voltage drop in the feeder in various types of distribution systems such as railway service.
Why does a series generator has rising characteristics?
It should be noted that the DC series generator has rising characteristics because its terminal voltage increases as the load current increases. However the terminal voltage starts to decrease at high loads due to excessive demagnetizing effect of armature reaction.
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