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Why electromagnetic torque opposes prime mover torque in dc generator?
Wiki User
∙ 11y ago
It's a practical example of the conservation of energy, and is explained by Lenz's Law. The direction of the load current is such that its magnetic field will create a force acting in the opposite direction to the force causing the conductor to move in the first place.
Wiki User
∙ 11y ago
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Operation of DC generator?
1) PRINCIPLE:Whenever a conductor cuts magnetic flux, dynamically induced emf is produced in it. ( Faraday's Laws of Electromagnetic Induction ). This emf causes a current to flow if the conductor circuit is closed.2 ) OPERATION:Field winding produces magnetic field in D.C. generator. Armature is coupled to the prime mover. Prime mover produces torque so the armature rotates. The armature cuts the magnetic field so the emf is induced in the armature. When load is connected to the armature, electric current flows from the armature conductors, through load and back to the armature conductors. Now, as current flows through the armature and it is in the magnetic field, torque is produced due to it. (This torque is called back torque). If the load on the generator is increased, the back torque increases so the torque of the prime mover also increases and the input power to the prime mover increases. In this way, the generator converts mechanical energy into electrical energy.It should be observed that the emf induced in D.C. generator, is A.C. ( so the emf induced in the armature is alternating in nature. ). Then with the help of commutator, it is converted into D.C. Rings and brushes are used to take the emf outside.
Why the synchronous machine rotate at synchronous speed?
The spatial distribution of the windings in the armature is designed in a way such that it produce a rotating field when a three phase source is applied to its terminals. The field windings have a DC field applied to it and it is rotated mechanically by a prime mover. If the prime mover tried to rotate the synchronous machine at speed higher than its synchronous value then the power output of the generator will increase and this causes the speed to "lock" again to the synchronous one. If the prime mover applied less torque then the machine will slow down but the power output will decrease DUE TO DECEASE in the applied torque and this cause the machine to "lock" again to synchronous speed of the grid. The same principle can be applied to synchronous motors except that torque is negative (i.e. the prime mover is applying negative torque)
What is reverse power of generator?
It is wise to start thinking of power in DC circuit. If a load is connected to a power source in a DC circuit, the corresponding VOLT CURRENT plot both will be in the positive quadrant. Of course, polarity must be correct. Now if the CURRENT (in the same polarity arrangement) happens to be in the negative quadrant, the power is said to be reversed. The same can be thought in an AC circuit. Taking a half wave cycle of both VOLT and CURRENT, one can apply the same understanding as in the DC circuit. If the AC circuit is capacitive or inductive, VOLT and CURRENT waves will be shifted according to the value of the capacitive or inductive load, and here one has to be aware. Adel Aljassar adel@al-jassar.net
Which statement describes an AC generator?
AC generator is a rotating machine with a rotor and stator winding, driven by another prime mover, which generates alternating current at a specified voltage.
What happen if a prime mover fails when two generators are in parallel?
It acts as synchronous motor by consuming power from the other generator....
Operation of DC generator?
1) PRINCIPLE:Whenever a conductor cuts magnetic flux, dynamically induced emf is produced in it. ( Faraday's Laws of Electromagnetic Induction ). This emf causes a current to flow if the conductor circuit is closed.2 ) OPERATION:Field winding produces magnetic field in D.C. generator. Armature is coupled to the prime mover. Prime mover produces torque so the armature rotates. The armature cuts the magnetic field so the emf is induced in the armature. When load is connected to the armature, electric current flows from the armature conductors, through load and back to the armature conductors. Now, as current flows through the armature and it is in the magnetic field, torque is produced due to it. (This torque is called back torque). If the load on the generator is increased, the back torque increases so the torque of the prime mover also increases and the input power to the prime mover increases. In this way, the generator converts mechanical energy into electrical energy.It should be observed that the emf induced in D.C. generator, is A.C. ( so the emf induced in the armature is alternating in nature. ). Then with the help of commutator, it is converted into D.C. Rings and brushes are used to take the emf outside.
What is relationship between load and frequency?
Speaking in plain english: as load increases, frequency decreases and vice versa. To understand it technically, you need to know what lenz's law and faraday's law of electromagnetic induction is. For a generator, as load (current drawn) increases, opposing (len's law) electromagnetic induced emf (faraday's law) in generator windings increases and hence it opposes the movement of prime mover. Thus the speed (rpm) of rotor decreases and hence the frequency of generated power output. Pranav saraswala.
Prime movers for power generating operation?
A "prime mover" is part of a generator - specificially the thing that's causing the generator to spin (such as a turbine). It is called the prime mover because it is what is causing the generator's rotation.
What is prime mover in a dc generator?
The prime mover in a DC generator is the mechanical device or system that provides the initial energy required to rotate the generator's armature. It could be an engine, turbine, or any other source that converts mechanical energy into rotational motion. The prime mover rotates the generator's rotor, inducing a magnetic field and generating electrical power.
What Turns the arm of a generator?
It is called the prime mover.
How generator run?
By help of prime mover which supplies the mechanical energy to the shaft of generator(in case of dc generators).
Antagonists are muscles that resist the actions of what and cause movement in the opposite direction?
Antagonist: A muscle that opposes a prime mover
What fuel used in DC generator?
Any generator, d.c. or a.c., is driven by a 'prime mover'. It's the prime move that uses fuel, not the generator! There are lots of different types of prime mover, including combustion engines (petrol, diesel), turbines (gas, water, air), etc.
Why the synchronous machine rotate at synchronous speed?
The spatial distribution of the windings in the armature is designed in a way such that it produce a rotating field when a three phase source is applied to its terminals. The field windings have a DC field applied to it and it is rotated mechanically by a prime mover. If the prime mover tried to rotate the synchronous machine at speed higher than its synchronous value then the power output of the generator will increase and this causes the speed to "lock" again to the synchronous one. If the prime mover applied less torque then the machine will slow down but the power output will decrease DUE TO DECEASE in the applied torque and this cause the machine to "lock" again to synchronous speed of the grid. The same principle can be applied to synchronous motors except that torque is negative (i.e. the prime mover is applying negative torque)
Muscle group antagonistic to the quadriceps femoris?
Quadricepts
What is reverse power of generator?
It is wise to start thinking of power in DC circuit. If a load is connected to a power source in a DC circuit, the corresponding VOLT CURRENT plot both will be in the positive quadrant. Of course, polarity must be correct. Now if the CURRENT (in the same polarity arrangement) happens to be in the negative quadrant, the power is said to be reversed. The same can be thought in an AC circuit. Taking a half wave cycle of both VOLT and CURRENT, one can apply the same understanding as in the DC circuit. If the AC circuit is capacitive or inductive, VOLT and CURRENT waves will be shifted according to the value of the capacitive or inductive load, and here one has to be aware. Adel Aljassar adel@al-jassar.net
How do generators run?
By help of prime mover which supplies the mechanical energy to the shaft of generator(in case of dc generators).
