Speed control of dc series motor - motor control , Electrical Engineering

Assignment Help:

Speed Control of DC Series Motor

A half  wave  circuit  for the  speed  control of DC  series motor is  shown in figure and corresponding wave from  is shown  in figure  consists  diac  and diode  to give the  triggering pulses to the SCR. Here SCR  is used to  control the armature voltage  of the DC motor.  By varying R2 firing angle α can be  controlled  of SCR. During the positive  half  cycle of input  ac voltage capacitor C will through R1 and R2.

SCR will get  turned  on when the  capacitor voltage Vc is equal  to the addition  of back emf Eb  of motor  and break over voltage VBO of the diac. By  varying  the resistance R2 the charging  time of  capacitor (r= R2C)  hence the speed of motor can be controlled. Basically it is  the armature voltage control method. In case  when SCR  is not conducting the  armature voltage will be there due to  the residual flux which  is approximate proportional  to the speed .

Due to  the fluctuation  in load will results the  change  in speed of motor and according  back emf of the motor will change. Since  the break over voltage of  diac is constant and back emf is varying  means the difference of Vc and ( VBO + EB) may increase or decrease as EB is increased or decreased respectively. The  firing  of SCR  depends on this difference. As  a results  the average dc voltage  across  the armature will change  and speed  of motor  can control  accordingly.

 


Related Discussions:- Speed control of dc series motor - motor control

Calculate the voltage regulation, The per-phase synchronous reactance of a ...

The per-phase synchronous reactance of a three-phase, wye-connected, 2.5-MVA, 6.6-kV, 60-Hz turboalternator is 10 . Neglect the armature resistance and saturation. Calculate the v

Basic specifications of a ujt, The very basic specifications of a UJT are: ...

The very basic specifications of a UJT are: Vbb(max) - The maximum interbase voltage that can be applied to the UJT (b) Rbb-the interbase resistance of the UJT (c) n - The

Electric current vs magnetic field, When a current is passed through a cond...

When a current is passed through a conductor, a magnetic field is created in its surroundings. We can represent this magnetic field by drawing 'field (or 'flux') lines' with two

What are the different types of distributing frames, Q. What are the differ...

Q. What are the different types of distributing frames used in exchanges? Ans: Different distribution  frames  used  in  exchange  are  displayed in  figure.  Each subscribe

Find the modulated signal in each case, Let the message signal m(t) = α cos...

Let the message signal m(t) = α cos (2πf m t) be used to either frequency-modulate or phase- modulate the carrier Ac cos(2πf c t). Find the modulated signal in each case.

Why earthing is required for any electrical equipments, Why earthing is req...

Why earthing is required for any electrical equipments, domestic installation and service building etc? For TL coaches what is the minimum I.R. value needed for new wiring? An

Measurment, emitter followers regulator

emitter followers regulator

Functions of regulatory body, Functions of Regulatory Body Set sta...

Functions of Regulatory Body Set standards through setting codes, by miscellaneous orders, by license conditions and by directions in tariff orders; Determine the tari

Reduction of sequential monte carlo in medium voltage, how can optimized th...

how can optimized the system through the matlab software?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd