Have you seen the code at all
Dear Sougata,
I haven't seen the entire code at all but just one table of delays for
sinewave. Also I have faint recollection of the block diagram.
Truly speaking Im not much PIC er. Im doing everything with ATMEL
micros. I have found this forum while searching for sinewave inverter.
I think it doesn't matter which company U use but design is more importatnt.
So I can understand code very well.
I also have Transformer Unit but it is for HT Instrumentation type.
I think that varying amplitude with delays and error adding will work only
maximum upto 70% of basic amplitude. After that U will have gross THD due
to most of delays at zero crossing very small.(It appears in class D amplifiers
of analog kind). I haven't seen whether such approach works with truly
variable amplitude or from 0 to 120% of the amplitude.
What I m saying is not double conversion but switchng of Buck Boost
mosfets with 2 ports from same PIC outputs and CORRECT amplitude there.(See attached bmp file.) In this s1 and s2 are mosfets whose timings is controlled to vary the voltage.
Im in India but near Mumbai so here not much Inverter brouhaha is there.
Melanie has agreed that this DSP method is not so good although everybody
is claiming otherwise.
I am also looking for design in which there should be no such bulky
transformer of 50Hz. If I have read right then proper driving of mosfets
would result in 20-40Khz output which is double modulated. this can use
high frequency transformer with centre tapped secondary and demodulator cum filter circuit which will give 50Hz output!!
As presently the transformer is costing about 50% of the total invertor
cost and one can imagine savings. Also as many circuits are having SMPS type charger for battery the advantage is obivious.(Compare APLAB 30V 1A
regulated supply with 250W computer smps,)
Hope to have more discussion on this.
regards,
dayama
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