Need circuit diagram for automatic electronic phase switch designed to supply an industrial and domestic single phase 230 V, 50 Hz load from three-phase four-wire mains 3х400+N in order to maintain uninterrupted power supply of essential single-phase loads and protect them against unallowable voltage variations in the mains.

 

need triac based only, not relay based and it must be cost effective and best quality

 

This request seems very much to be asking for a serious design effort that would cost quite a bit from even a low priced engineer consultant.
What can be found are published circuits to do this cyclo-conversion. They are called cyclo-converters and some of the designs are public domain available. That is the extent of my free engineering consultant service. Now the TS has the keywords to use in a search.

 

for automatic phase selector switch development, should I go with atmega328 or pic microcontroller???? which one would be the best to achieve the goal???? out of 3 phases, this switch must automatically select single ideal phase in no time for the smooth operation of the connected load

 

should I go with microcontroller based circuit or opamp comparator based automatic phase selector switch design?final pcb must be highly cost effective and best in terms of performance

 

Micro controller will offer many more options/wider range for control.

 

Is this home work?

 

With the TS claiming to be "executive management/owner", this sounds a lot like a request for engineering support of s for-profit project.
The tried and proven scheme is indeed a triac arrangement often called a Cyclo-Converter. This is a mature scheme that has been well documented and has published designs.
Considering that all of the triacs will be controlling 400 volt phases, very consistent delay isolation will be required.Another option could be a simple 3-phase rectifier followed by an inverter.

 

Micro controller will offer many more options/wider range for control.

should we go for stm 32 or atmega 328 or arduino uno ???? which one would be better to choose?

 

should we go for stm 32 or atmega 328 or arduino uno ???? which one would be better to choose?

Not really that familiar with those choices, I deal mainly with the Picmicro range of processors.

 

Not really that familiar with those choices, I deal mainly with the Picmicro range of processors.

which pic microcontroller will be the best to choose????? can you help me with the pin no???

 

I think the Arduinos are cheap toys for kids.

 

A perusal of the PicMicro web site APP notes may provide an answer, This is not a trivial circuit/project.
A search of the web may bear fruit.

 

which pic microcontroller will be the best to choose????? can you help me with the pin no???

It is highly likely that you are in a better position to make that determination than any of us are. Particularly since you have not deigned to supply even a soupçon of information about your project.

 

Once again: The TS has requested quite a few hours worth of work, just to sketch and select the triacs. The isolation of the triggers will not be a small thing, either.
And no details about that 400 volt 3-phase, plus neutral, either. What frequency? Y or Delta?
Protection against "unallowable variations"is an interesting way to put it.
The simple method would be star connected constant voltage transformers, close to a unity ratio.

interestingly, with 400 volts delta connection the line to neutral is 231 volts. Done with no triacs or arduino toy computers.

OR the TS can use that circuit published for that failedsine wave AC supply that broke, in that other thread. Except no need for the inverter, just three phase bridge rectifier, and then the H- bridge amplifier with the oscillator driving it.Some adjusting of component values required, of course.