Tricky but Easy Electrical Engineering!
DC Machines can be tested by three different methods namely Direct Method, Indirect Method and Regenerative Method. Direct Method of testing of DC Machine, also known as Brake Test (if carried out for a DC Motor) will be discussed in this post. Direct method is suitable for small DC machines. In Direct Method, the DC … Read more
In Permanent Magnet DC Motor or PMDC Motor, permanent magnet is used to create the working flux in the air gap instead of field winding. The construction of rotor is same as that of the Conventional DC Motor i.e. rotor of PMDC Motor consists of armature core, armature winding and commutator. Generally, there are two … Read more
DC Series Motors are widely used for the purposes requiring high starting torque like in Hoist, Crane, Electric Traction etc. In this post we will discuss the reason behind the high starting torque of DC Series Motor. For any DC motor, torque is directly proportional to the flux and armature current i.e. Ƭ = KaØIa … Read more
This may come in our mind that what exactly will happen if we operate a DC Motor at a speed more than the rated speed. In fact, the thermal capacity of the motor decides at what speed it can run and for how long. There is always a safety factor considered in the design which … Read more
As discussed in the previous post “Speed Control of DC Motor”, speed of DC Motor can be controlled by varying the terminal voltage Vt of the DC Motor. Ward-Leonard Method is the application of this principle where the terminal voltage Vtof DC Motor is varied to control the speed of DC Motor. Ward-Leonard Method of … Read more
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
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