Week 3 Session 7

Solution :

The different motor used in electric vehicle is

• Brushed Permenent magnet DC motor
• BLDC motor
• Permenent magnet synchronous motor
• Three phase induction motor
• Switched reluctance motor

1)Brushed Permenent magnet DC motor

The permanent magnet dc motor can be defined as a motor which includes a permanent magnet pole is called Permanent Magnet DC Motor. In this motor, the magnet can be used to make the flux working within the air gap in its place of the field winding. The rotor structure is similar to the straight DC Motor. PMDC Motor’s rotor includes armature core, commutator, & armature windings. Normally, in a conventional DC motor, there are two kinds of winding such as armature as well as Filed.

Advantage

• It gives the maximum torque at low speed.
• easy speed control

Disadvantages

• Bulky structure
• Low efficiency
• Heat generation at brushes

2)Permenent Magnet BLDC motor

A brushless DC motor consists of a rotor in the form of a permanent magnet and stator in the form of polyphase armature windings. It differs from the conventional dc motor in such that it doesn’t contain brushes and the commutation is done using electrically, using an electronic drive to feed the stator windings.

Advantages

• No rotor copper less
• More efficiency than the induction motors
• It is lighter
• Smaller
• Better heat dissipation
• More reliable
• High starting torque

Disadvantages

• Short constant power range
• When speed increases torque decreases
• Expensive

3) Permenent magnet synchronous motor

The permanent magnet synchronous motors are one of the types of AC synchronous motors, where the field is excited by permanent magnets that generate sinusoidal back EMF. It contains a rotor and stator same as that of an induction motor, but a permanent magnet is used as a rotor to create a magnetic field. Hence there is no need to wound field winding on the rotor. It is also known as a 3-phase brushless permanent sine wave motor.

Advantages

• can be used without using gear systems in a different speed range
• More efficient
• Compact
• Best suitable for in-wheel application
• Gives high torque even at least speeds

Disadvantages

• During the in-wheel operation at high speed it losses the high amount of iron

4) Induction Motor

The electric motor which runs asynchronous speed is known as induction motor, and an alternate name of this motor is the asynchronous motor. Induction motor mainly uses electromagnetic induction for changing the energy from electric to mechanical. Based on the rotor construction, these motors are classified into two types namely squirrel cage & phase wound.

Advantages

• It is the most mature commutator less motor drive system
• By employing the field operation control it can be operated like separately excited DC motor
• It is cheap
• High efficiency
• Less Maintenance
• Don't require starter
• it can withstand rugged environmental condition

5) Switched Reluctance Motor(SRM)

Switched reluctance motor works based on the variable reluctance principle. The rotating magnetic field is created with the help of power electronics switching circuit.

The main concept is the reluctance of the magnetic circuit is depending upon the air gap. Hence, by changing the air gap between the rotor and stator, we can change the reluctance of the motor.

Advantages

• It is simple
• Robust construction
• High speed
• Low cost
• Constant long power range
• Fault-tolerant
• Higher power density

Disadvantages

• Makes so much of noise
• Low efficiency
• Larger
• Heavy
• Complex and design control
• Problem creating in manufacturing and controllability
• Low power