Speed Control of DC Series Motor, Speed Control of DC Shunt Motor
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
Speed control means intentional change of the drive speed to a value required for performing the specific work process. Speed control is a different concept from speed regulation where there is specific natural change in speed due change in load on the shaft.
Types, Necessity, Working Principle, Construction | DC Motors
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
DC motors are self-starting motors, whenever the armature and field winding of a DC motor receives supply, motoring action takes place. So, DC motors do not require any additional device to start it.
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
The performance of a DC motor can be determined from its characteristics curves known as motor characteristics. Following are the three important characteristics of a DC motor. Why DC series motor is always started with load?
with Solved Example Problems
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
The types of DC motor: 1. Separately excited DC Motor 2. Self excited DC Motor
Types of DC Machine Excitation
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
The performance characteristics of a de machine are greatly influenced by the way in which the field winding is excited with direct current. There are two methods of excitation two methods of a dc machine.
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
The parallel paths of dc machine armature are symmetrical and each has an induced emf and a resistance. The armature can be represented by the DC Machine Circuit Model with voltage and a series resistance
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
Torque is nothing but turning or twisting force about an axis. Torque is measured by the product of force and radius which the force acts. Consider a wheel of radius 'r' meters acted on by a circumferential force 'F' Newton
Derivation
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
The armature conductors are generally connected in two different ways, viz. lap winding and wave winding. For lap wound armature, the number of parallel paths is equal to the number of poles
DC Machines
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
The basic principle of operation of DC motor is that "whenever a current carrying conductor is placed in a magnetic field, it experiences a force tending to move it".
DC Machines
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
Let us consider a single turn coil ABCD rotated on a shaft within a uniform magnetic field of flux density. It is rotated in an anticlockwise direction.
DC Machines
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
DC generator with its major parts as given below: i. Magnetic Frame (or) Yoke ii. Poles, Interpoles, Windings, Pole Shoes iii. Armature iv. Commutator v. Brushes, Bearings and Shaft.
Subject and UNIT: Electrical and Instrumentation Engineering: Unit II: DC Machines
An electrical generator is a rotating machine which converts mechanical energy into electrical energy. This energy conversion is based on the principle of electromagnetic induction.