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Forum Index : Electronics : Turning a Toyota Prius into a "portable" generator
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Haxby Guru  Joined: 07/07/2008 Location: AustraliaPosts: 423 |
Poida can you elaborate on the Vfb? I'm reading it as not the same as the warpverter feed forward 2 to 4v input correlating to (in my case) 200 to 400vDC input. Yours is a feedback derived from the output voltage yes? What voltage range is best? |
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poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
I have zero warpverters. I used a microcontroller to take one phase's gate control signals and construct a simulated voltage from any of the 8 half bridges being ON+, ON- or SHORTED. In my case I used 2 Arduino Due boards, I needed 3 digital to analog output channels. (one board gives 2 channels only) wronger than a phone book full of wrong phone numbers |
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| poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
The feedback system needs a low voltage sample of the AC output voltage as seen at the toroid secondary winding. I use a 240V to 12V small power transformer, then a full bridge to rectify and maybe a 10uF cap to smooth. Then this is fed into a voltage divider, maybe a 5K multi turn pot and this is set to give 2.5V for when the AC output voltage is 240V (or whatever you want) The control code is of a type called closed loop. The code compares Vfb with 2.5V and if Vfb is less, the code increases the AC output voltage until it equals or exceeds 2.5V. And if Vfb is greater than 2.5V, the code reduces the AC output voltage to bring it down. the 2.5V I mention is sort of what it is, when you build something using my code (nanoverter) you can see what it actually is. The test inverter on my bench has it as 2.76V. wronger than a phone book full of wrong phone numbers |
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Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 648 |
It is wise to select the voltage divider resistors and pre set the multiturn trimpot for the 2.5VDC *before* the inverter is fired up for the first time. Use the very same small transformer as mentioned above. I neglected this and as luck has it the trimpot wiper was at the wrong end, resulting in well over 300VAC output. This blew the fan external temperature controller which was only rated for 260VAC. All happened before I had a chance to wind back the trimpot wiper. |
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| Haxby Guru Joined: 07/07/2008 Location: AustraliaPosts: 423 |
I hope Warp is still here, I haven't seen him for a few days! After lots of hesitation, I'm testing at high voltage and with some light loads. Over around 250vdc I'm getting quite a lot of buzzing from the transformers. Is this to be expected? This is with or without a load. Video here I'm monitoring the gate drive and sine wave and all that looks good. |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
Yes, I've been wondering the same thing, I hope he is ok. Mark has mentioned visiting him a few times in the past, maybe he might have his phone number or could check on him. I do have his address in Melbourne but I'm half way across the country from there. From what I could make of the hum, it doesn't sound like a distress hum ... more of just a rattly transformer noise ... hopefully anyway. Cheers, Roger |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Ah, had a really interesting experience today. Was just reversing out of my driveway to go to the supermarket, and a police car parked right across my driveway blocking my exit. Couple of coppers got out and asked me if I was Tony. Anyhow, it seems I have been missed on the internet, and the cops came around to see if I was dead or still alive. My internet connection went down a week ago and everything here looked normal, all the lights on my modem are lit saying I had internet connection, but no actual network connection could be made. Different computer with different operating system did not fix it either, and neither did different cables. Being almost deaf does not help as I cannot use a telephone, so I just waited for my ISP to fix the problem which appeared to be at their end. Anyhow the cops had a go at fixing it, and were as baffled as I was as to the cause. Then doing a full modem reset and restart fixed it. Funnily enough I had already tried that several times myself but with no improvement. Just as I was writing this Phil (Haxby) rang my front doorbell. So after a week of wondering, everything has happened in just the last hectic hour or so. So guys, I am back on the internet again. Edited 2021-03-03 14:10 by Warpspeed Cheers, Tony. |
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| Haxby Guru Joined: 07/07/2008 Location: AustraliaPosts: 423 |
For the record, Rogerdw raised the alarm with the police after not being able to make contact. It's great to see the thebackshed community coming together like this. Tony, I guess you will have to let this forum know whenever you go on holidays, otherwise we will come looking for you  |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
The police said it was "Roger" so I figured out who that was. I did a similar thing myself a few years ago. A mate in Queensland suddenly dropped off the radar, and I contacted the local police. The local sergeant (of a small regional town) sent me a very nice e-mail saying my mate was still alive and kicking and "well known" in the community. I don't know if that is quite the same thing as "known to the police" haha, as he is a medical doctor, although also a bit of a colourful character. Cheers, Tony. |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
Glad to hear all is well Tony, as you can see I was a little concerned. Hopefully it was not too much of an embarrassment having the boys in blue turn up. I did look for Mark's email knowing he had visited at times but his message bank is full, so no joy there. So thanks Phil (Haxby) for taking the initiative to go knock on your door, it's great to see some care taken in an often miserable world that we live in. And I have to compliment the Vic police too, as I just rang to ask how I could go about checking and they took it all very seriously and had people around there inside probably 20 minutes ... then rang me back to say all was well. Great job. Cheers, Roger |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Not an embarrassment, more of a surprise really. My conscience is completely clear, but I do wonder what the neighbors thought. I also wonder how often the coppers knock on someones door to find some poor devil stone dead. So its probably a pretty routine occurrence for them. Its also a reminder how dependent we have all become on the internet for almost everything we do these days. Cheers, Tony. |
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CaptainBoing Guru Joined: 07/09/2016 Location: United KingdomPosts: 2075 |
I hate to read when the police finally breakdown someones door to find some poor soul has turned to soup after 3 months and no-one noticed, so this is by far the better option. Glad everyone is OK. perhaps we should have a "roll call" thread... lots of names not posting |
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InPhase Senior Member  Joined: 15/12/2020 Location: United StatesPosts: 178 |
I'm just glad you're not black Tony. Because then the cops would have shot you dead in front of your house. Because, you know, they're all foaming-at-the-mouth racists that execute innocent black men for no reason. Saw it on the news. |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
Yeah I try and avoid the news, but I still see that it happens from time to time. Very sad. And you're right about lots of names not posting, it's very quiet here at the moment. Cheers, Roger |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
These were actually two really nice guys. When I said my internet was busted, they offered to come in and try and fix it for me. How about that !! And they did try too, spent about half an hour trying. I score the cops eleven out of ten for that effort. Cheers, Tony. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
O/k just catching up on a few things. Peter built a "Warpverter simulator" that takes the eight gate driver waveforms and converts these via a lookup table into an analog voltage via a D/A converter. I did this myself just using an eprom and a bipolar digital to analog converter. This will produce a low voltage sine wave directly from the control board, requiring no power mosfets, no transformers, and no high battery voltage. Much safer when experimenting with control strategies and software. It can all be done on the workbench with all low dc voltages, and there is nothing expensive or dangerous that can really blow up if you make a little mistake... Voltage feedback is more accurate, but its slow to react, and must be made slow to ensure stability. Feedforward is much faster, and the extra speed goes a long way to reducing light flicker whenever heavy loads switched in or out. The grid voltage is up and down all the time, and household appliances do not seem to care one way or the other, as long as there is at least 200v. But light flicker can be really annoying if you are (say) reading, and the refrigerator is constantly cycling on and off. Phil was also asking about transformer buzzing. My Warpverter buzzes, the laminations have loosened up considerably over the last 3+ years, but as I am deaf as a post, and the inverter is out in the shed, It does not matter. Toroids should buzz less, but buzzing may still occur if the windings are loose. There is nothing peculiar about the Warpverter that makes a Warpverter buzz any more than any other inverter, or in fact working off a grid sourced sine wave. The transformer voltage waveforms are all rectangular and very abrupt, but ALL the primary and secondary windings see a continuous smooth unbroken sine wave current, once all four inverters and transformers are in full operation. Its why during construction and some initial testing running only one or two inverters the waveforms look pretty horrible. But with all four inverters running together in harmony, the ragged waveforms all suddenly go through a miraculous change into a clean sine wave with less than 1% total harmonic distortion. If your transformers still buzz, try running them directly off the grid. If it still buzzes, and it probably will, its the transformer itself that is the problem, not the Warpverter drive waveforms. Assuming of course all your mosfets/IGBTs are working properly. Cheers, Tony. |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
A very wise and interesting topic ( checking up on close members) . Aaron and myself chat every week ,just to check how the property is for water, horses, and any stuff we are working on .. You are right to be concerned, as we crowd do play with some fairly "touchy" stuff_Now I don't want to get into a slinging match ,,, but you know what I mean.. My wifey(Ilda), often comes down to my workshop or taps a broom handle on the floor to check if I'm stiff OK. I'd be happy to check on anybody that sort of lives alone if they feel that would be helpful, even just to have a chat . So, if you want, drop me a line and we'll check now and then .. Have a nice day, Bruce Bushboy |
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| solarsim Newbie  Joined: 10/01/2021 Location: AustraliaPosts: 10 |
Very Pleased that warp is fine!.... I'm just checking in from time to time waiting for parts from china. Mostly arrived now... I should be getting on with a few plans shortly.. |
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| Haxby Guru Joined: 07/07/2008 Location: AustraliaPosts: 423 |
Update: So I'm testing with small loads of 100 watts and virtually everything is going well with my warpverter. Hooray! But.... I think my warpverter voltage sense input is sensitive to picking up noise. At around 320vdc in, and when I'm actively turning the scratchy Variac knob, sometimes the warpverter turns off all IGBTs for just a split second. The warpverter is running from a hi-link 5v smpsu and that supply is filtered through a common mode filter. The warpverter sense terminals are not filtered at all. Should I add another filter or a capacitor for the sense terminals? Red circle in the photo shows filtered HVDC input. Yellow line shows voltage sense wires.  |
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| Haxby Guru Joined: 07/07/2008 Location: AustraliaPosts: 423 |
Vsens resistors are 3.3k and 400k. Could these high values be the problem? |
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