Many have you seen a string of circular disc like structure on transmission line structure as shown below. Some are hanging vertically and some are horizontally arranged. These are called Overhead line insulators. Fig. Overhead Line Insulators Overhead Line Insulators are used to separate line conductors from each other and from the supporting structures or … Read more
DC machine whether it is motor or generator will have four essential parts. They are Field System Armature Commutator Brush and Brush gear 1. Field System The objective of field system in DC machine is to provide uniform magnetic field, within which armature rotates. For small rating motors permanent magnets are used and for large … Read more
AC power has become popular and advantageous because of easy generation, transmission with fewer losses to long distances due to stepping up voltage and stepping down the voltage to the desired level. In Industries 70% of the motors and drives used are Induction motors, hence ac motors in general means induction motors. Induction motors were … Read more
Traction is defined as ‘the act of drawing or pulling especially by a motive force‘ (drawing of carriage by horse constitute traction). In mechanical terms, it is defined as the ‘adhesive friction between the wheel and the surface on which it moves‘ (between a car tire and road). Traction system can be broadly classified as … Read more
Braking in DC motor is employed to make the dc motor to halt from operating condition by applying a brake. It is to be considered that significant difference exists between the words ‘braking’ and ‘breaking’, should not get confused. In dc motors we apply the brake to make the dc motor halt. Different braking methods … Read more
In DC series motor field coils or winding will be in series with the armature winding. The conductor size of the field winding will be having a thick wire (large cross section) with lesser turns. Advantages of DC Series Motors The main application where series motors are best suited is for traction applications. The torque … Read more
In spite of the wide use of AC supply, DC machines have some advantages compared to ac motors and are used in industries for some applications. Some of the DC Motor Applications in Industries are listed below. Applications of DC Series Motor DC series motors are widely used for electrical traction applications, i.e, these motors … Read more
In thermal power plants, dc motors are employed for certain control and critical emergency operations which are supplied by dedicated batteries. DC motors operate as backup drives for normal ac drive systems when AC power supply to the plant is lost. In thermal power plant, the dc motors find applications for performing control functions such … Read more
Magnetic field The Magnetic field is a force which is generated due to energy change in a volume of space. A magnetic field is produced by an electrical charge in motion e.g. current flowing in a conductor, orbital movement and spin of electrons. The magnetic field can be described by imaginary lines as shown in … Read more
Proportional-Integral (PI) controllers are used in many industrial control applications. The main purpose of using Proportional and Integral (PI) in process system is to improve the steady-state accuracy of the system without affecting the stability of the system. Proportional action responds quickly to the error deviation and the integral action will act slowly but offset … Read more