Question

Explain the difference b/w an A. C and a D. C generator.
For 3 marks!
No spams! ✨​

Answer 1

Difference Between AC and DC Generator

Sl. No.

Differentiating Property

AC Generator

DC Generator

1

Definition

AC generator is a mechanical device which converts mechanical energy into AC electrical power.

DC generator is a mechanical device which converts mechanical energy into DC electrical power.

2

Direction of Current

In an AC generator, the electrical current reverses direction periodically.

In a DC generator, the electrical current flows only in one direction.

3

Basic Design

In an AC generator, the coil through which the current flows is fixed while the magnet moves. The construction is simple and costs are less.

In a DC generator, the coil through which the current flows rotates in a fixed field. The overall design is very simple but construction is complex due commutators and slip rings.

4

Commutators

AC generator does not have commutators.

DC generators have commutators to make the current flow in one direction only.

5

Rings

AC generators have slip-rings.

DC generators have split-ring commutators.

6

Efficiency of Brushes

Since slip-rings have a smooth and uninterrupted surface, they do not wear quickly and are highly efficient.

Both brushes and commutators of a DC generator wear out quickly and thus are less efficient.

7

Short Circuit Possibility

As the brushes have high efficiency, a short circuit is very unlikely.

Since the brushes and commutators wear out quickly, sparking and short circuit possibility is high.

8

Armature

In case of AC generators, the armature is always the rotor.

In case of DC generators, the armature may be either rotor or stator.

9

Rotating Parts

The rotating part in an AC Generator is low current high resistivity rotor.

The rotating part in a DC generator is generally heavy.

10

Current Induction

In AC generator, the output current can be either induced in the stator or in the rotor.

In DC generator, the output current can only be induced in the rotor.

11

Output Voltage

AC generators produce a high voltage which varies in amplitude and time. The output frequency varies (mostly 50Hz to 60Hz).

DC generators produce a low voltage when compared to AC generator which is constant in amplitude and time i.e. output frequency is zero.

12

Maintenance

AC generators require very less maintenance and are highly reliable.

DC generators require frequent maintenance and are less reliable.

13

Types

AC generators can of varying types like 3 Phase generators, Single phase generators, synchronous generator, induction generator, etc.

DC generators are mainly two types which are Separately excited DC generator and Self-excited DC generator. According to field and armature connection, they can be further classified as DC series, shunt or compound generators respectively.

14

Cost

The initial cost of AC generator is high.

The initial cost of DC generator is less when compared to AC generators.

15

Distribution and Transmission

The output from AC generators is easy to distribute using a transformer.

The output from DC generators is difficult to distribute as transformers cannot be used.

16

Efficiency

AC generators are very efficient as the energy losses are less.

DC generators are less efficient due to sparking and other losses like copper, eddy current, mechanical and hysteresis losses.

17

Applications

It is used to power for smaller motors and electrical appliances at homes (mixers, vacuum cleaners, etc.)

DC generators power very large electric motors like those needed for subway systems.

Answer 2

HERE IS YOUR ANSWER:--------

SOME OF THE MAJOR DIFFERENCES BETWEEN A.C. GENERATOR AND D.C. GENERATOR ARE:-

FOR A.C. GENERATOR

1. "A.C. GENERATOR MEANS "ALTERNATING CURRENT GENERATOR".SO BY NAME ONLY WE CAN SAY THAT A.C. GENERATOR PRODUCES THE ALTERNATING CURRENTS WHICH REVERSES THE DIRECTION OF THE COIL.
2. AC GENERATORS ARE GENERALLY USED TO GENERATE ELECTRICITY OR CURRENTS FROM A.C. MAINS WHICH IS THEN SUPPLIED TO HOMES,TRANSPORT AND INDUSTRY.
3. IN THE A.C. GENERATOR WE CONNECT THE TWO ENDS OF THE COIL TO THE OUTER CIRCUIT BY TWO FULL RINGS OF COPPER KNOW AS THE SLIP RINGS .

FOR D.C. GENERATOR:-

1. IN D.C. GENERATOR THE CURRENT WHICH IS FLOWING FLOWS ONLY IN THE SINGLE DIRECTION THEY DON'T CHANGE THE DIRECTION OF CURRENT PERIODICALLY.
2. IT IS USED IN THE GENERATION OF ELECTRIC CURRENTS IN THE HEAVY MOTORS MOSTLY IN THE INDUSTRIES.
3. IN D.C. GENERATOR WE CONNECT THE TWO ENDS OF THE COIL TO A COMMUTAOR OF TWO HALF RINGS.

THESE THREE ARE THE MAJOR DIFFERENCES HOWEVER THERE ARE MANY MORE LET ME MENTION MORE:

• AC GENERATORS CAN'T PRODUCE THE DC POWER HOWEVER DC CAN PRODUCE AC POWER.