hello, i need the schematic diagram for bidirectonal thyristor converter PS( pulses system) and the way in which the circuit operates.I've tried through google but didn't find what i want exactly so i might have done wrong so plesae correct me to the right thing.
Well you know what a normal rectifier looks like...
Well replace the diodes with thyristors and you have the rectification stage
Now take another rectification stage and turn it up-side-down (so the thy are pointing the opposite direction to the rectifier-thy) and you have the inverter stage
connnect the together on a common DC-link and you have it
what i'm looking for is the pulse system circuit (which is intended for triggering the whole thyristors in such a way that enables the two sets to work in the desired way)
what i'm looking for is the pulse system circuit (which is intended for triggering the whole thyristors in such a way that enables the two sets to work in the desired way)
and here in lies the problem.. you have not once said what you concider the "desired way" is. There are loads of ways to fire thyristors, all dependent on their application (current-source, cycloconverter,slip-recovery....)
again I stress NOT ONCE! I for one am not a mind-reader and at a guess neither is anyone else
Even though they are controlling a DC motor via an AC sourced SCR bridge rectifier, you might want to look at the "universal firing circuit" descibed here:
**broken link removed**
But to control a DC motor using a DC supply, I think you should be using MOSFETs and not SCRs. To use SCRs you will need a large commutating capacitor to turn off the SCR because they are latching devices on DC.
In general; for a DC supply, use FETs. But it looks like from your other thread at: https://www.electro-tech-online.com/threads/designing-of-thyristory-converter.25233/
that you can use SCR's because your power supply is 3 phase AC....
The link to the PDF file I posted above should give you a starting point for driving the SCRs with a pulse transformer.
There are many pulse systems differ by changing firing angles between the set itself and also between the two sets(rectifier+inverter) but i think that the most useful practical way is "seperate control" which depends on sending pulses to one set and removing pulses from the other sequentially....
I need help concerning PSR and PSI cause all that i know is the chart symbols for each of them so i need the real practical circuit used in such cases.
where VA,VB,Vc are 120 phase-shifted of each other.