Methods of Speed Control of Induction Motor

Out of all the electrical machines, Induction Motor is the most used machine in industries. More than 90% of motors used in industries are squirrel cage induction motor due to its rugged and maintenance free design. Generally an Induction Motor operates at almost constant speed as the load is varied. But in some industrial applications, … Read more

Stator Voltage Control of Induction Motor

Stator Voltage Control of Induction Motor is a method for the speed control of induction motor by changing the stator terminal voltage. Stator terminal voltage in this method is changed either by adding a series resistor, series inductor or auto transformer in stator circuit. But addition of series resistance is quite inefficient due to losses … Read more

Rotor resistance Control of Induction Motor

Rotor resistance control is one among the various methods for the speed control of induction motor. In this method of speed control, the rotor circuit resistance is varied by connecting a variable external resistance. This method is only applicable for slip ring or wound rotor induction motor (WRIM). As in squirrel cage induction motor (SCIM), … Read more

Pole Changing Method – Speed Control of Induction Motor

Pole changing method is a speed control scheme of induction motor. In this scheme, the number of pole pairs is changed by changing the field connection. In induction motor, field winding is wound on the stator while the armature winding is wound on the rotor. Therefore in this scheme, provision for changing the stator winding … Read more

Speed Control of DC Motor by Varying Field Flux

In previous post “Speed Control of DC Motor” we discussed the method of speed control of DC Motor by Armature Circuit Resistance Control Method. In this post we will discuss the method of speed control of DC Motor by varying the Field Flux which is known as Field Weakening Method. By Field Weakening Method of … Read more

Speed Control of DC Motor

DC Motor speed control means to have full control on the speed of DC Motor. The variation in speed of DC Motor because of variation in load is not the speed control. Therefore intentional variation in speed of DC Motor is called Speed Control. As we know that for a DC Motor having armature resistance … Read more