|
Power section of a DC drive....
|
|
|
Power section of a DC drive
consisting of power handling components can take any of the following shapes.
-single phase semicontrolled -single phase fully controlled -three phase semicontrolled -three phase fully controlled By ‘Semicontrol’ and ‘Full
Control’ we mean the type of control we have over the power controlling
devices, i.e. thyristors or diodes. In semicontrolled type, in a three phase
configuration, only half of the devices have control over the current flowing
through them. The sketch below shows that three out of six current carrying
devices are diodes and three are thyristors. Seventh component across the +ve
and -ve terminals is a diode and called FREEWHEELING diode. It is necessary
to freewheel the energy in the inductance of the motor. With all six devices
under control of gate pulses, the electronic circuit has total control over
the motor current. This configuration is also known as 6 pulse configuration. |
|
|
|
|
Download PDF version of these pages.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Speed control not satisfactory
|
|
|
|
|
|
|
|
|
|
|
|
|