ELECTRIC DRIVE
Electric drive is electrical energy is generated, transmitted, distributed and is utilised in the various fields.some of this electrical Energy is utilised in domestic uses but large part of this generated electrical energy is utilised in the industrial applications.
Electrical energy is finding its extensive use in the industry for driving the electrical machines.
Electric motors used as drive for various machines in industries are khown as electric drive.
Concept of electrical drive:
System employes for motion control is called drive.
An electric drive is defined as a form of machine equipment designed to convert electrical energy in to mechanical energy and provide electrical control of this process.
Electrical drives was first designed in russia in the year 1893 by B.S.lakobi.
Block diagram of electrical drives:electric drive
(1) source:it is either d.c. or a.c. supply.
(2)power modulator: it performs the following function:
-it convert electrical energy received from the source in the form suitable to the motor i.e. if the source is d.c. and an induction motor is to be employed then it converts d.c. into a variable frequency a.c.
-it selects the mode of operation of motor i.e. motoring or braking.
(3) load: load is usually a machinery to accomplish a given task. Eg-fans, pumps, washing machine etc.
(4)motors:motors commnly used in electrical drives are DC motors-shunt series , compound and permanent megnet .induction motor- squirrel cage and wound rotor ; synchronous motor- wound field and permanent magnet ; brushles dc motors ; stepper motors ; and switched reluctunce motors.
(5) sensing unit : it is employed for sensing the drive parameters, such as speed motors current etc. Which may be required either for protection purpose or for closed loop operations. These signals are fed to control unit.
(6) control unit: it controls the power modulator besides generating commands for the protection of motor and power modulator. It usually operates at much lower voltage and power levels.
0 Comments: