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 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 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 are the advantages and disadvantages to use Series DC motor?
Speed regulation in the series motor is quite poor. With the increase in the load speed of the machine decreases. (DC shunt motor maintains almost constant speed from no load to full load). DC series motor should always require to be loaded before starting the motor.
What is the main disadvantage of 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.
Why is series generator not favorable?
Variation in load resistance causes the terminal voltage to vary. The terminal voltage will start falling, at saturation armature reaction effect becomes pronounced at large load current. Hence, series generators are not used for delivering power at a constant voltage.
What advantage does a shunt motor have over a series motor?
Compound motors have a field connected in series with the armature and a separately excited shunt field. The series field provides better starting torque and the shunt field provides better speed regulation.
Why is the chief advantage of a DC series motor?
The primary advantage of the DC motor is that it can develop constant torque over a wide speed application. Power supply is an important consideration in the application of DC motors.
What is significance of DC series motor?
A series motor has very high starting torque and is commonly used for starting high inertia loads, such as trains, elevators or hoists. This speed/torque characteristic is useful in applications such as dragline excavators, where the digging tool moves rapidly when unloaded but slowly when carrying a heavy load.
Why DC series motor is suitable for traction?
DC series motor has develops high torque at low speeds, low torque at high speed, this is the basic requirement of traction unit. Commutating property of series motor is good so we get sparkles commutation. Torque is unaffected by variation in supply voltage. DC Series motor maintenance cost is less.
What are the applications of DC series motor?
Application of DC Series motor
- Cranes.
- Air compressor.
- Lifts.
- Elevators.
- Winching system.
- Electric traction.
- Hair drier.
- Vacuum cleaner and in speed regulation application.
What are the disadvantages of shunt?
There are some disadvantages of a transistor shunt regulator are given below,
- 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 is the difference between shunt and series motor?
A series motor respond by decreasing its speed with small increase in current for a given load torque. A shunt motor holds its speed nearly constant with large increase in input current for same amount of load torque.
What are the advantages and disadvantages of shunt?
Zener Controlled Transistor Shunt Voltage Regulator
| Advantages of Linear Voltage Regulator | Disadvantages of Linear Voltage Regulator |
|---|---|
| Design is very simple | Low efficiency |
| Less output ripple | Space requirement is large |
| Response time is fast | Voltage cannot be increased |
| Less noise | A heat sink is sometimes required |
Why are generators not connected in series?
output voltage is sum of both i.e 2V. and current is zero. when we load it they can only provide max current C, larger current can damage them. in parallel connection they also very but in series current will flow from generator, while in parallel we can save generator or transformer.
What are series generators used for?
They are used for supplying field excitation current in DC locomotives for regenerative breaking. This types of generators are used as boosters to compensate the voltage drop in the feeder in various types of distribution systems such as railway service. In series arc lightening this type of generators are mainly used.
What are advantages of paralleling synchronous generators?
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.
What is series motor?
A series motor is a direct current motor that has two windings that are in series, with the same current flowing through each. Use of series motors is generally limited to cases where a heavy power demand is necessary to bring the machine up to speed, as in the case of certain elevator and hoist installations.
How does a series motor work?
A series DC motor converts electric energy to mechanic energy based on the electromagnetic principle. In this type of DC motor, a power supply terminal sits at one end of the armature and field coils. By applying the voltage, power starts in these terminals and passes through armature and field windings.
What are the disadvantages of DC motors?
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 disadvantages when a series motor specially designed for DC operation is placed across an AC supplies?
However, a series motor which is specifically designed for dc operation suffers from the following drawbacks when it is used on single-phase ac supply:
- Its efficiency is low due to hysteresis and eddy-current losses.
- The power factor is low due to the large reactance of the field and the armature winding.
Contents