Analysis of 3 Phase Induction Motor | Electrical Machines | EE
Real Life Application
A 3 phase induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor can therefore be made without electrical connections to the rotor. An induction motor's rotor can be either wound type or squirrel-cage type. A 3 phase induction motor is used widely. Basically they can be used in two ways:
1. A three-phase induction motor without any VFDs (Variable Frequency Drive). In this case, the speed and torque is constant at steady state. The cost of these types of motors is very cheap. Some of the examples of these types are fan of AHU (Air Handling Unit), circulation water pumps of HVAC, feed water pump of fire extinguish and so on.
2. There are so many types of VFD (Variable Frequency Drive) in the market and they
are really well-made, cheaper and small. Therefore, most of electrical engineers and customers want to adopt VFD in order to saving energy and control more accuracy.
To understand the concept with clarity it’s important to have basic idea of working of Induction Motor, which is explained in the video. There are many parameters in Induction Motor, where approximations can be taken without much deviation, which in turn makes the analysis of 3 phase induction motor very simple. For example, the analysis of the equivalent circuit, torque-slip characteristics, speed-control of 3 phase induction motor becomes very simpler. All these techniques are explained in the video.