14-03-2012, 03:17 PM
dc motor speed control
ABSTRACT
Every country needs the industrial development which keeps the country at high level. The entire world move with the help of the electronic and electrical equipment which makes the life of a man very simple.
One of the component (or) device that makes work very simple of the entire industries is simply a machine called motor. That means a motor is now ruling the industrial world. There are so many types of motor are there, now we discuss about the most important motor that is DC separately excite motor whenever there is a motor there must be a fine control of speed. To get the required speed of the motor we are using a fully controlled converted by using triacs which gives our quadrant operation of DC. Motor which is very useful in industries where variable speeds are require.
DC motor will give very accurate and easy control of speed we are using armature voltage control of DC motor which gives above and below rated speed. Then by controlling voltage we can control speed. In order to control the armature voltage we are controlling firing angle which decides where we have to starts conducting of triac. Four quadrant operations is done by triggering he triacs in a proper time. To run the motor in forward direction we give the pulses to triacs in such a way that during +Ve cycle (T1, T3) get the pulses and during –Ve cycle (T2, T4) get the pulses. Similarly for reverse direction of motor we are giving during +Ve cycle (T2, T4) get pulses during –Ve cycle (T1, T3) get pulses.
These pulses are interchange simply using a single switch ‘S1’. The four quadrant operation is get by a single switch ‘S1’ and speed control that means different speeds are obtained by varying the reference voltage, that is by varying the potential meter.
