Re: [pvusers] Re: Question on inverting DC to AC

[subu.muthu@philips.com]

Hello: I have good experience in working with the inverters both standalone and utility interactive types.
It is not easy to modify a 60Hz inverter to 50Hz inverters because you have to deal with changing the fundamental 
60Hz (either sinusoidal or modified)  waveform generation to 50Hz. With the current inverter technology, it is 
commonly implemented by firmware/software with microcontrollers.  With the microcontroller implementation, technically 
one can modify the software code to make the inverter to generate 50Hz waveform with the existing hardware and filter components, and
the same inverter platform can be used for different markets such as Japanese/North American with different firmware.

However, for you, you need to have the access to the program (source code) first,  and no inverter manufacturer supplies this.  
Code reverse engineering  is difficult.  In addition, you have to deal with the timing issues, programming the micro etc.

The same thing applies for the voltage, however, technically it will be easier to adapt a 120VAC inverter to 100VAC inverter.
This can also be achieved by modifying the software (timing is not an issue, you have to modify the modulation index)
 or just by adding a step down transformer (This is not the solution because  of the added cost with the magnetics).

In addition, You may have to make the inverter to comply with the Japanese utility and safety standards if required.

Hopefully this helps.

Subu Muthu./

Christopher Witmer <cdwitmer@spamcop.net> 09/09/02 05:48 PM

To:        pvusers@crest.org         cc:        (bcc: Subu Muthu/BRQ/RESEARCH/PHILIPS)         Subject:        [pvusers] Re: Question on inverting DC to AC         Classification:

I'm trying to build a system for use in Eastern Japan, which is
50Hz/100VAC. Inverters designed specifically for the Japanese market are
more expensive than others, such as 60Hz/120VAC inverters, since the
Japanese market is small. If I could obtain a (relatively) cheap
inverter designed for the USA market and then get it modified for
50Hz/100VAC operation, that could be a viable solution for me. Does
anyone have any idea about how difficult it would be to make such a
modification to an existing inverter?

Thanks,

Christopher Witmer

Robert Warren wrote:

>  If you were building an inverter (and I know you aren't from the
question you asked), then it is no big deal to step up the DC voltage
with a bridge rectifier/capacitor circuit: a lot of inverter
manufacturers have entirely gotten away from using big transformers.




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