f=4.44fqm
In dc motor, the armature conductors are revolving in the magnetic field and emf is induced in the armature conductors. The direction of the induced emf is in opposite direction to the applied voltage as per Flemings left hand rule. So, the induced emf in motor is called as back emf or counter emf. Vydehi
equation of ac machine
ediot
leakage reactance in induction motor depends on the reluctance of the path in which the leakage flux is establishing. with the increase in stator current the leakage flux also increases but it cannot maintain linear relationship because of saturation of the leakage flux path, even though current is increasing the flux will not increase and it'll be constant after saturation. this leakage flux links with the stator winding and induces emf which will be opposite to the supply voltage causes drop in applied voltage , the drop in the applied voltage is represented with the leakage reactance. as flux is responsible for the induction of emf , the increase in current does not increase flux after saturation and therefore emf also doesnot increase so the leakage reactance is not constant throughout the machine operation...
It is defined as when the conductor is placed between the magnetic field and since when the conductor cuts the path of the magnetic field emf is produced... The basic Faraday's Law of electromagnetic induction...
The equation that best describes the induced emf due to the movement of a rod in a magnetic field is given by Faraday's Law of Electromagnetic Induction, which states that the induced emf () is equal to the rate of change of magnetic flux () through the loop formed by the rod. Mathematically, it can be expressed as -d/dt.
How many methods can be used to control the speed of Single Phase Induction Motor? 1.injecting emf method 2.by frequency control method 3.induced voltage method
induction motor never runs at synchronous speed, if it does so there would not be any relative speed between stator flux and rotor and no emf will induce in rotor and we can not apply motor principle as we need current carrying conductor in magnetic field.
How do you proof of the existence of back emf ?
The emf equation of signal phase transform
Electromagnetic induction
The current in an induction motor decreases as it accelerates due to reduced rotor impedance and increased back EMF. As the motor speeds up, the rotor reacts with the rotating magnetic field produced by the stator, causing a decrease in the current needed to maintain acceleration. This decrease in current helps to improve the motor's efficiency and reduce energy consumption.
The electromotive force (EMF) equation of a synchronous reluctance motor can be expressed as ( E = 4.44 \times f \times \Phi \times T ), where ( E ) is the induced EMF, ( f ) is the frequency of the supply voltage, ( \Phi ) is the magnetic flux per pole, and ( T ) is the number of turns per phase winding. In synchronous reluctance motors, the EMF is generated due to the rotor's reluctance variation in the magnetic field, rather than traditional winding-induced EMF, which is typical in other motor types. The motor operates at synchronous speed determined by the supply frequency and number of poles, contributing to its efficiency and performance characteristics.
In dc motor, the armature conductors are revolving in the magnetic field and emf is induced in the armature conductors. The direction of the induced emf is in opposite direction to the applied voltage as per Flemings left hand rule. So, the induced emf in motor is called as back emf or counter emf. Vydehi
There is a motor in a generator which carries out this electromagnetic induction,as we switch on the generator the magnetic field lines between that motor get cuts off by the rotating coil which cause change in flux and change in flux cause induced emf,cue to emf at different points of coil cause current to get flow and then generator will get on.
the phenomenon of generation of emf by means of change in flux.
equation of ac machine