Electrical drives, what exactly is a drive?
An electrical drive is an electronics control system of electrical motor speed and torque.
In many industrial applications its important to control electrical motors speed in the production process
Where does electrical drive work?
Electrical drive is used in factories, electrical trains, robotics and many other industrial applications such as assembly lines must run at different speeds.
How can a 3 phase induction motor speed be controlled?
Speed control of 3 phase induction motor can be controlled by one of the following methods:
- Number of poles of the motor changing, as induction motor speed if function of poles number (Speed = 120 Frequency / poles number)
- V/ f controlling or frequency control
- Voltage controlling, but reducing voltage reduces motor torque
Three phase induction motor speed equation
Speed of induction motor is function of frequency and poles number of motor windings
N = 120 * f / p
While 120: is a constant.
f : is source frequency
p : number of poles number of the motor winding
How to control AC motor speed with an electrical drive?
An AC motor speed and torque are constant, but it can be controlled by controlling input frequency and voltage, The drive which controls the motor is called VFD or VSD
VFD (variable frequency drive), while VSD is (variable speed drive), this drive is used from smal applications to large ones
VFD drive is based on power electronics and is programmable, while motor parameters such as motor speed, voltage, frequency and connection type are set to the VFD.
