Electrical engineering

Many of us know that, in electrical power generation the frequency must be kept constant for satisfactory operation of power system. But, the question is, why the frequency is to made constant?  Before this, let us first understand the basic operation of the alternator. Operation of alternator: An alternator (synchronous generator) is a machine which converts mechanical energy into electrical energy at a particular voltage but at a constant frequency. The rotor part consist of field winding and stator part consist of armature winding. The field winding is excited with D.C supply. The turbine is mechanically coupled with the rotor to give the mechanical power input to the alternator. Now, when rotor rotates the flux due to field winding cuts armature conductors and according to the faraday's law of electromagnetic induction, an emf is induced in the armature conductors. The frequency of induced emf is given by: So, to generate constant frequency, the machine must always be driven at...

Which are the must conditions to be fulfilled for the operation of an Electric Motor? An electric motor is an electro-mechanical energy conversion device i.e converts electrical energy into mechanical energy. The motors are generally classified as: D.C motors. A.C motors. Operating principle It works on the principle of lorent'z force law i.e " Whenever a current carrying conductor placed inside a magnetic field experiences a force". Conditions for the operation of an electric motor For any type of motor, the two conditions are must to be satisfied. They are as follows: There must be the interaction of two magnetic fields. Both the magnetic field must be stationary with respect to each other i.e relative speed between two fields must be zero. The number of stator poles and rotor poles must be same. What happens if this conditions are not satisfied? The operation of an electric motor depends on the presence of electromagnetic torque. The expression for electromagnetic torq...

Power efficiency and all day efficiency of transformer The definition of  Power efficiency and all day efficiency of a transformer is as given below Definition: Power efficiency is defined as the ratio of Output power to the Input power. Mathematically, it is represented as  All day efficiency  is defined as the ratio of Output energy to the Input energy calculated over 24 hours. Mathematically, it is represented as  Q) Now, the question is why two efficiencies are required for the transformer? Let us first know about the types of transformers based on the location. They are as listed below: Power transformer. Distribution transformer. Power transformers are located on the sending end/generating end side of power system  whereas the distribution transformer are located on recieving end/load end side. What is the need of Power efficiency? The power system is an interconnected network and the power transformer is located on the sending end side of the system. Henc...