Introduction to electric machines

First here are a few key terms:

In an example like UoN super bike we start with an energy source to provide energy which is connected to a battery management system to ensure batter last for as long as possible.

Then you have a DC to AC power electronic converter which is controlled by the control computer that is affected by the speed of the motor bike

Why do we need electric drive?

Four Quadrant operation

Lets use a car as an example

Three main components:

Speed of motor

Direction of the torque

Direction of the torque of the load

Torque is positive if it is in the direction of motion

There is 4 different ways of driving car

Going forwards,Reverse, Down hill and up hill

1st Quadrant

When driving the car forwards your torque will be forward as there is a forward accelaration

2nd Quadrant

When going downhil you are breaking so car doesnt go too fast so you may be going upwards but the torqur is going to be negative

3rd Quadrant

Reversing,

Torque is negative and speed is negative as u are accelerating backwards

4th Quadrant

Your going up hill but reversing so Torque is positive

Another example is an elevator

Introduction on power electronics

This is universal speed equation

N(rpm) = 120f/P

N = speed of the machine

f = supply frequency to the machine

P = number of poles in the machine

With VSI you can change the voltage and frequency . 90% of applications use this because CSI needs a Large inductor.

Introduction to Electrical Machines

Applications

Anything that moves, Anything that rotates , Anything that converts Electrical to Mechanical or vice versa

There are 3 types of electrical machines

Universal Motor

Single Phase motors and

Three phases

These aren’t the actual terminologies

Conventional Machines(1st gen)

• 1. DC Machine

• 2. Induction Machine

• 3. Synchronous Machine

Second generation Machines

• Brushed PM DC machine

• PM AC Machines

Third Gen Machines

1. Brushless PM DC Machine

2. Brushless PM AC machine

3. Reluctance MAchines