DESIGN OF DC MACHINE

                   DESIGN OF DC MACHINE

 DESIGN OF DC MACHINES

DC GENERATORS, MOTORS, BRAKES NOW REPLACED BY AC GENERATORS DUE TO THEIR  LOWER GENERATION AND TRANSMISSION COSTS, HIGH DENSITY, GREATER RELIABILITY. HOWEVER, DC MACHINES DUE TO THEIR VERSATILITY CAN BE DESIGNED FOR VARIOUS RANGES OF VOLTAGE/CURRENT OR SPEED/ TORQUE CHARACTERISTICS FOR STEADY AND TRANSIENT STATE CONDITIONS. BUT SUPPLY FED TO THESE IS NOT FROM ROTATING DC GENERATOR BUT FROM AC FED POWER RECTIFIERS.

DC GENERATORS- SMALL BACKUP POWER IN REMOTE/ISOLATED AREAS OR IN STANDBY GENERATING PLANTS(LIKE UPS)

MAIN CONSTRUCTION

1. FIELD

2. ARMATURE

3. COMMUTATOR

- YOKE OR FRAME FORMS THE MAIN SUPPORT TO THE MACHINE MADE OF COST IRON/STEEL/FABRICATED ROLLED STEEL.

-FIELD WINDING MAGNETIZE THE POLES WHEN CURRENT IS PASSED THROUGH IT AND HENCE RESPONSIBLE FOR PRODUCING MAIN FLUX. IT IS LOCATED ON STATOR OF MACHINE

-ARMATURE IS THE ROTATING PART AND IS THE PLACE WHERE THE MAIN CONVERSION OF POWER OCCURS. IT CONSISTS OF:-

1. ARMATURE CORE WITH SLOTS

2. ARMATURE WINDING PLACED IN SLOTS.

FIELD AND ARMATURE SYSTEM SEPARATED BY AIR GAP.

-COMMUTATOR IS MOUNTED ON ROTOR AND PERFORMS RECTIFICATION THAT USED TO CONVERTS AC POWER INDUCED IN ARMATURE CONDUCTORS INTO DC POWER(FOR GENERATOR) AND ALTERNATING TORQUE TO DC TORQUE (FOR MOTOR)

DC GENERATOR- PRINCIPLE OF EMI (CONDUCTOR MOVED IN A MAGNETIC FIELD PRODUCES EMF)

DC MOTOR- PRINCIPLE OF INTERACTION (CURRENT CARRYING CONDUCTOR WHEN PLACED IN MAGNETIC FIELD EXPERIENCES A FORCE GIVEN BY(FLEMING'S LEFT-HAND RULE)