1. A seperately excited DC motor operating from a single phase half controlled bridge at a speed of 1400rpm, has an input voltage of 33 sin 314t and a back emf of 80V. TheSCRs are fired symmetrically at an angle of 30 deg in every half cycle and the armature has a resistance of 4ohms. Calculate the average armature current and the motor torque.
The input voltage should be Vs=330sin314t volts.
If it was 33v peak then current will come as negative value so the machine will not work as motor this the question itself violates as it is mentioned as dc motor.
1. A seperately excited DC motor operating from a single phase half controlled bridge at a...
i. The speed of a separately excited dc motor is controlled by a one-phase full-wave converter. The field circuit is also controlled by a full-wave converter, see V supply) Vs pk-150V Ra-0.310 L Rf 152O E-63V α. 1-35A Figure 3 The AC supply voltage to the armature and field converters is one-phase, 150Vpeak, 50Hz. The armature resistance Ra-0.31Ω, the field circuit resistance Rf-152Ω, and the motor voltage constant is Kv-1.3V/A. The armature current corresponding to the load demand la-35A The...
Question 4 (Could be considered as Quiz 3- 4.5 pts). An armature-controlled DC motor of figure below has the following characteristics: Ra=1.2 ohms, L. - 0, KT = 0.06 N-m/A (motor-torque constant), K = 0.06 V-s/rad (back-emf constant). It has maximum speed of 500 rad's with a maximum current of 2 A. We suppose that all possible frictions are represented in friction torque Tr=0.012N-m. R: armature resistance, 2 La armature inductance, H is : armature current, A is: field current,...
Q1. Draw the equivalent circuits of a separately excited and a shunt DC motor. [20] Q2. Derive the speed-torque relation for a DC motor: [40] 0 = VR, Kø (KØ)??ind Q3. A DC motor's speed can be controlled by either changing the field resistance, changing the armature voltage or changing the armature resistance. Of these three, which one is the best method for DC motor speed control and which is the worst? Give reasons. [40]
Analyze a DC series phase-controlled motor drive with single-phase, full wave, controlled AC/DC rectifier in continuous conduction mode (CCM) of operation. Draw the motor voltage and current waveforms and write the equations (instantaneous and averaged). Please note that the waveforms and equations have been presented in class for a DC separately-excited motor drive.
The speed of a separately excited de motor is controlled by a one-phase full-wave converter. The field circuit is also controlled by a full-wave converter and the field current is set to its maximum value. The AC supply voltage to the armature and field converters is one-phase, 400V, 50Hz. The armature resistance Ra 0.232, the field circuit resistance Rf- 1812, and the motor voltage constant is Kv 1.3V/A - rad/s. The armature current corresponding to the load demand Ia 42A...
A power electronic converter used to drive a separately-excited DC motor for application in Sohar, Oman as shown in Figure Q2. Let R = 0.25 , K = 0.62 V/rpm.Wb, (flux per pole) = 175 mWb. The used converter is a single-phase, controlled full-wave bridge rectifier. Assume the firing angle is 45°, and the average speed is 1300 rpm and torque constant K is 9.55 of K. Assuming the motor current is continuous; calculate the armature current drawn by the...
3) A saperately excited DC motor has the following parameters: Ra = 10 Ke = 0.4 V/rpm. Wb O = 0.2 Wb The motor speed is controlled by a full-wave bridge rectifier. The firing angle is set at 45, and the average speed is 1500 rpm. The applied AC voltage to the input of the bridge rectifier is 220Vrms - 50 Hz. a) (10p) Please draw the complete circuit. (converter + motor) b) (10p) Please find the armature current. c)...
3) A saperately excited DC motor has the following parameters: Ra = 10 Ke = 0.4 V/rpm. Wb 0 = 0.2 Wb The motor speed is controlled by a full-wave bridge rectifier. The firing angle is set at 45°, and the average speed is 1500 rpm. The applied AC voltage to the input of the bridge rectifier is 220Vrms - 50 Hz. a) (10p) Please draw the complete circuit. (converter + motor) b) (10p) Please find the armature current. c)...
(i) A 220 volts, 825 rpm, 125 A separately excited DC motor has an armature resistance of 0.05 2. It is fed from a single phase fully controlled rectifier with an ac source of 225 Volts, 50Hz. Assuming continuous conduction calculate (a) Firing angle for 1/4"hrated motor torque and 750 rpm (b) Motor speed for a=160 degrees and rated torque 5 Marks (ii) Draw and explain with neat circuit diagram of a DC drive circuit, which works with positive output...
3. A controlled single-phase fiull-wave controlled rectifier is connected in a de motor drive in Figure 4. The de motor armature inductance can be assumed large enough such that any motor curent ripple is negligible. (a) Assuming negligible supply reactance, show that the average rectifier output voltage V, in tems of the supply ms voltage E and the firing angle a, is given by 2/2E (6 marks) cos a _ (b) Given that the supply voltage is 230V, 50HZ and...