Honda EU series - stator voltage

[NRGdreamer]

Greetings all,

Very excited to find this forum!

I see that there is a 36V/48V DC charging version of the Honda EU3000is, the AplhaGen DCX3000. Seeing that the PMA on the eu3000 must be able to develop ~48V, has anyone modified these generators to tap into their PMAs directly?

Anyone know what kind of voltages the smaller EU series can develop at the PMA?

[Mike]

Good question.   If these units can be modified for a reasonable quality DC output to feed some Midnite Controllers I would be interested.
I wonder if it would be possible to " break out " the DC, and make the unit "switchable " between a 70 Volt DC output to its usual inverter output ?

Mike.

[SPSInc]

I'd be willing to bet the output of the PM is a high voltage providing a minimum of 200V rectified DC to the inverter. Probably even closer to 300 - 400Vdc. The inverter can then switch the high voltage DC rail through an IGBT H-Bridge to produce the 120Vac / 60 Hz output. The 120Vac sine wave has a peak of 170V so the inverter will likely require a greater than 200Vdc rail to account for voltage loss in the IGBTs and filter.

I have an older version of the Alpha unit. Its PMG had 3 outputs on it each being 3 phase. One set for 48Vnom, one set for 36Vnom and one high voltage for an inverter. It is a 3KW output with a honda 6.5HP engine with a variable speed controller on it. It can regulate at 39 or 52 Vdc. They (Alpha) ran the output of the PMG into a control board that has a bunch of SCRs on it. The SCRs control which set of windings is rectified (36 or 48) and also help to regulate the voltage during load dumps until the engine speed can slow. I would assume the new 36/48Vdc would work about the same way. Only concern I would have is these were meant for maintaining the load on the batteries and not really charging. I don't know if there is any adjustment to increase the battery voltage to an acceptable charging point.

I'm not using the generator if anyone has interest in it. It only has a few hours on it.

[NRGdreamer]

Hello SPSInc.

Great info about the AlphaGen DCX3000. I have been watching these on Ebay and they sell for considerably less than EU3000s, and I envisioned this unit as my standby generator for the house, being that it is able to meet average electrical consumption. It feeds a 48V battery bank (a small bank ~200AH) that is connected to a Xantrex XW6048 along with a 4kW PV array.

Anyways, staying on topic. From looking at pictures of the stator, it looks like many high density coils that generate higher voltage and rely on their massive parallel arrangement to meet current requirements. So that is pretty much in line with what you said about generating higher voltage than the final output. Coming from the industrial world with variable frequency drives, the "DC link" is higher voltage than the AC output (600VDC on a 480VAC drive). IGBTs modulate this at high frequency to produce three sinusoidal waves for the three phases.

I thought hard about the voltage ranges that these guys probably produce, and considered feeding the rectified DC into a higher voltage MPPT controller (like Schnider's 600VDC PV to 48V charge controller). Seems like it would be well suited to handle transient spikes during demand drop-offs.

So does the DCX3000 have a different stator than the EU3000is? When you say "older" has it gone through several evolutions?

Have you ever checked out Kholer's 6VSG DC generator? Too bad it is $5k... but not a bad price considering the cost of the PMG and the enclosure.

I might be interested in your DCX3000... but it is really early for me to buy it. Still haven't pulled the trigger on the alternate energy system.

[SPSInc]

Here are some pictures of the version I have.

[NRGdreamer]

Fascinating! That is not a EU3000is based design whatsoever.

I think it will be too noisy for my use. How much do you want for it?

I would be really happy if I could find an AlphaGen curbisde 3.5kW

[SPSInc]

I will send you a PM