MEP 831A 4x 3 Phase AC DC Rectifier Sample Circuit for the Genset connoisseur

[peapvp]

I thought we may through this sample wiring diagram as food for thought into the mix.

This AC DC Rectifier Sample Circuit will rectify each of the four individual 3 Phase Winding Sets of the standard 831A Genhead and bus them together on the DC side, then it will go through a 6th Order Chebyshev Lowpass Filter, to reduce the AC ripple to a bare minimum.



This circuit will allow you to keep using your current generator head after the Inverter failed

The DC Output can be used to either feed directly into a Solar Grid Inverter, if such inverter has a High Voltage DC Input (besides Solar Panel etc).
This would be a 200V Class Device

It could also be connected for instance to the WJ 200 Hitachi Series VFD's on Terminals P/+ and N/- and then using the VFD to provide 3 Phase 208/230 VAC 50/60 Hz Output

It can also connect to a wide variety of COTS Regen Units

The list here is basically endless and should get you inspired to figuring out of what to do with your 831A with a blown inverter

Cheers

 

[DD58]

This is very interesting. I wanted to do this but have no idea how to. I have a friend that’s an electrical engineer. I’m going to shoot him the print and see if he could get a board built. If he can I’ll pick up another 831 and try it. Thanks for this!!


Sent from my iPhone using Tapatalk

 

[Digger556]

Those are all good thoughts.

I had considered feeding the DC bus of a VFD, but it seemed kinda hacky. The grid-tied inverter is an appealing option, but I need to dig into these more. Do they make models that don't need a grid reference to operate?

Idealing, finding one that could run standalone or grid-tied could enable paralleling of multiple 831a's.

Maybe I need to start shopping for units with dead inverters, lol.

 

[Digger556]

Midnite Solar sells a MPPT charge controller, that works with wind or hydro generation, with 200 Vdc input and is programmable to work with 12-72V battery banks of various chemistry. The 831A's 24V battery could be rewired to be charged from the controller amd be used as a buffer supply for an off the shelf 24V inverter.


The 831 would mimic the wind or hydro generator. The charge controller would have programmable input power limits to keep it from overdrawing and stalling the engine.

Product - MidNite Solar

MidNite Solar Product Page.

www.midnitesolar.com

 

[peapvp]

Midnite Solar sells a MPPT charge controller, that works with wind or hydro generation, with 200 Vdc input and is programmable to work with 12-72V battery banks of various chemistry. The 831A's 24V battery could be rewired to be charged from the controller amd be used as a buffer supply for an off the shelf 24V inverter.


The 831 would mimic the wind or hydro generator. The charge controller would have programmable input power limits to keep it from overdrawing and stalling the engine.

Product - MidNite Solar

MidNite Solar Product Page.

www.midnitesolar.com

The US is far, far behind in this technology field compared to Europe and Japan especially.

In Japan all inverters used, have a 200V class DC Input (up to 370VDC) besides a AC connection to power the built in Battery Charger.

Europe is following this lead.

In Japan, they have been running a complete DC distribution grid in every manufacturing facility.

They convert incoming 3 Phase Utility either 200V or 400V class to DC
200V Class = up to 390VDC max
400V Class = up to 760 VDC max

any and all VFD’s, Servo Amplifiers etc etc from every machine are connected to this DC Building Grid.

this allows for a complete utilization of any Bemf, being available through the drive to DC Grid instantly.

Air Conditioning Compressors are now Permanent Magnet Surface Mount PMSM 96 Pole Motors, driven by PM capable VFD’s yielding a 98% efficiency

so, you may want to look at Japanese or German made Solar Inverters

 

[peapvp]

I am posting here as example the Manual for the Hitachi RCU’s for the interested reader.

The smallest 200V Class they have, has a 11KW capacity

the two outputs B+ and B- of the proposed 831A rectifier system would connect to the RCU P (B+) and N (B-) terminals.

RCU stands for Regenerative Converter Unit or simplified Regen

This is all food for thought and meant to be suggestive only, to expand the possible uses for these gensets