Fried Travel Power

[dmr]

Probably power transistor rather than thyristors, but yes the topology is different since the voltage coming out of the alternator is 300v or so AC. So it has first to be rectified, then chopped (or shaped, since its a sine wave output) into 50Hz AC. An inverter tends to have lower voltage (12v or whatever) conversion into AC and then a transformer to step up the voltage - at least that's how smaller ones work, Ive never seen a circuit for a multi-kw inverter. It is the final stage of step-up transformer that makes the output floating on an inverter, whereas there is no need for an equivalent on the TP and that's why its not floating.

 

I did have a peep inside my black box travelpower.

In addition to the signal electronics (which I think includes a processor of some sort), there are two great big black things that look nothing like any transistor I have ever seen. Sadly I did not get any numbers off them. As they are turning DC into AC a simple thyristor would not do the job, so I reckon they are a "gate turn off" thyristor of some kind. There are also two substantial toroidal jobbies so this duplication fits in with the idea of separate Live and Neutral drives.

I believe Electrolux (or Dometic) would not disclose the circuit diagrams so Cox's spent ages tracing it from the PCB.

 

........Dave

[GUMPY]

Ahem! Dictionary definition of an inverter: Any device for converting a direct current into an alternating current. The device you metion will have another name that I forget, maybe transverter or something?

 

But I still maintain that in common Boatie parlance the word inverter carries with it the expectation of voltage increase, so to call a TP an inverter, whilst correct, is just going to cause confusion! Sometimes making yourself understood is more important that being exactly correct.

Better tell the maufacturer that they are wrong then.

In industrial circles its common to call any device that changes the operating frequency an inverter.

The toy stuff that we use on boats does not set the international standards

[jelunga]

Try dropping this guy an email. He is the customer service / technical bod at Victron in the UK and used to work with Gibbo. He was of help to me when my Heart Inverter died. I now have a Victron Phoenix 12-3000-120.

 

KWadsworth@victronenergy.com

 

His name is Kevin Wadsworth

[Tim]

Better tell the maufacturer that they are wrong then.

In industrial circles its common to call any device that changes the operating frequency an inverter.

The toy stuff that we use on boats does not set the international standards

 

I think you'll find that all industrial 'inverters' for motor applications convert the incoming AC to DC then re-convert to AC for the output.

[GUMPY]

I think you'll find that all industrial 'inverters' for motor applications convert the incoming AC to DC then re-convert to AC for the output.

Indeed they do but thats inside the box so as far as a user is concerned its ac-ac

[Tim]

Indeed they do but thats inside the box so as far as a user is concerned its ac-ac

 

I've always thought that in this case the term 'Frequency Converter' would be better.

[Timleech]

Not eveb dc to ac

We use 380v50hz in inverters to produce variable drive to 380v motors all that effectivly changes is tbe frequency of the op

Dont think it hits dc anywhere

 

The usual VFD Inverter drive arrangement is, AFAIK, to convert Ac to DC and then back again, much as is done in a Travelpower box, except that the inverter drive output is 3-phase and variable frequency.

 

Tim

 

I've always thought that in this case the term 'Frequency Converter' would be better.

 

They're also known as Variable Frequency Drives (VFD), but that is more the common usage in the US than here. I agree it tells you more about the purpose of the box, but it's main constituent is still an inverter.

 

Tim

[nicknorman]

The toy stuff that we use on boats does not set the international standards

No, but the dictionary probably does!

 

I think you'll find that all industrial 'inverters' for motor applications convert the incoming AC to DC then re-convert to AC for the output.

Yes, it's difficult to see how else they would work. And that is exactly what the TP does of course.

[smileypete]

I did have a peep inside my black box travelpower.

In addition to the signal electronics (which I think includes a processor of some sort), there are two great big black things that look nothing like any transistor I have ever seen. Sadly I did not get any numbers off them. As they are turning DC into AC a simple thyristor would not do the job, so I reckon they are a "gate turn off" thyristor of some kind. There are also two substantial toroidal jobbies so this duplication fits in with the idea of separate Live and Neutral drives.

I believe Electrolux (or Dometic) would not disclose the circuit diagrams so Cox's spent ages tracing it from the PCB.

May be a couple of IGBTs, either way could be worth getting the part no. soon before they might go pop! A hi res digital photo of the board may get a lot of useful info.

 

cheers, Pete.

~smpt~

 

I did have a peep inside my black box travelpower.

In addition to the signal electronics (which I think includes a processor of some sort), there are two great big black things that look nothing like any transistor I have ever seen. Sadly I did not get any numbers off them. As they are turning DC into AC a simple thyristor would not do the job, so I reckon they are a "gate turn off" thyristor of some kind. There are also two substantial toroidal jobbies so this duplication fits in with the idea of separate Live and Neutral drives.

I believe Electrolux (or Dometic) would not disclose the circuit diagrams so Cox's spent ages tracing it from the PCB.

May be a couple of IGBTs, either way could be worth getting the part no. soon before they might go pop! A hi res digital photo of the board may get a lot of useful info.

 

cheers, Pete.

~smpt~

[dmr]

May be a couple of IGBTs, either way could be worth getting the part no. soon before they might go pop! A hi res digital photo of the board may get a lot of useful info.

 

cheers, Pete.

~smpt~

 

 

 

Cox Automotive reckon they have stockpiled enough components to keep the TravelPower running for quite a few years, so I am going to rely on them.

Its my nature to fix everything myself but in this case, as Cox have taken time to acquire the expertise, I'm going to trust them. My own experience of power electronics is that its not always easy to fix! A component failure often takes a few others with it and if you don't replace all the bad ones the new ones just go pop.

 

..........Dave

[by'eck]

I did have a peep inside my black box travelpower.

In addition to the signal electronics (which I think includes a processor of some sort), there are two great big black things that look nothing like any transistor I have ever seen. Sadly I did not get any numbers off them. As they are turning DC into AC a simple thyristor would not do the job, so I reckon they are a "gate turn off" thyristor of some kind. There are also two substantial toroidal jobbies so this duplication fits in with the idea of separate Live and Neutral drives.

I believe Electrolux (or Dometic) would not disclose the circuit diagrams so Cox's spent ages tracing it from the PCB.

 

........Dave

 

Why wouldn't the main drive semiconductors be MOSFETS's as in the Dynawatt and also in this generic 12 volt DC to 230v AC inverter schematic?

 

[nicknorman]

Why wouldn't the main drive semiconductors be MOSFETS's as in the Dynawatt and also in this generic 12 volt DC to 230v AC inverter schematic?

 

 

Could be, but IGBTs seem to be the device of choice in high voltage applications, and the strange package shape alluded to supports that theory. They are quite similar in many ways but IGBTs have a lower forward voltage drop in high voltage devices.

Edited February 9, 2013 by nicknorman

[dmr]

Assuming I am correct about thyristors,

They might have been used rather than transistors because:....

Its quite an old design and MOSFETS where not well established/trusted at the time.

Its designed in Sweden and Scandinavians have always done odd electronic design???

The designer had a background in power electronics and new thyristor design well????.

and most likely....

Inverters work at low voltage and step up via a transformer whilst TravelPower is a high voltage system and there is very limited choice of big transistors at high voltage.

 

.........Dave

[nicknorman]

Assuming I am correct about thyristors,

They might have been used rather than transistors because:....

Its quite an old design and MOSFETS where not well established/trusted at the time.

Its designed in Sweden and Scandinavians have always done odd electronic design???

The designer had a background in power electronics and new thyristor design well????.

and most likely....

Inverters work at low voltage and step up via a transformer whilst TravelPower is a high voltage system and there is very limited choice of big transistors at high voltage.

 

.........Dave

I don't know what age device we are talking about, but IGBTs were available in the 80s. Can you do sine wave invertion with thyristors?

[dmr]

Yeah, I reckon IGBT too, though when did TravelPower first appear?????

Still IGBT and thyristor are both four layer semiconductors so I was on the right track!!!!!

 

.........Dave

[by'eck]

Yeah, I reckon IGBT too, though when did TravelPower first appear?????

Still IGBT and thyristor are both four layer semiconductors so I was on the right track!!!!!

 

.........Dave

 

Did they look like this?

 

[dmr]

Certainly a bit like that. I think they were International Rectifier devices.

Will need another look inside later this year to get dog hairs out of the cooling fan, will take photos.

Its said that 90% of Morris dancers are computer programmers, so what percentage of CWDF members are electronic engineers?????

 

..........Dave

[Philippe]

Quick update on progress with this issue.

 

I shared this thread with my mechanic and Cox's (thanks again for the useful discussion ) and it does seem that the most likely culprit is the connection between the Travel Power and Victron. Apparently this is not an isolated (no pun intended!) incident and there have been other reported instances of TPs being fried like this.

 

Next step is to get the TP box rebuilt again, refit it to the boat but without the connection into the Victron and then run an extension cable through to the galley. I'll then try running the washing machine and various other 240v appliances from this for a while. If everything works out okay without problems then a more permanent solution can be fitted to put a dedicated socket in the galley. If it doesn't work out then I'll just bin the TP completely and buy a suitcase generator.

 

I may get a suitcase generator (Honda EU20i/EU26i probably) anyway as emergency backup and so I don't have to run the engine if I moor up for a while when I depart CCing in a month or two.

[dmr]

If it does not work then do not literally bin the Travelpower, get one more fix from Cox's and put it on eBay

 

Black box jobby going for £750 "buy it now"

Silver box in an auction, currently at £250

 

............Dave

[Philippe]

If it does not work then do not literally bin the Travelpower, get one more fix from Cox's and put it on eBay

 

Black box jobby going for £750 "buy it now"

Silver box in an auction, currently at £250

 

............Dave

 

Would make sense except for the fact that it costs more than that to get it fixed each time

[Philippe]

Another quick update on this ongoing saga...

 

Travel Power fixed again and received end of last week but my mechanic not available until end of this week to refit.

 

In the meantime I purchased the USB interface for my Victron and took a look at the settings. Power Assist mode is set on and the Ground Relay switch is set on so that neutral/earth is connected when the inverter is running and disconnected otherwise.

 

Now the scenario for the last blow up of the Travel Power was that the ampage limiter on the Victron was set too low initially when the washing machine was running and the washing cycle began turning off and on. I then turned up the limiter to 16 amps and the Travel Power went bang!

 

I’m wondering if when I was running the washing machine the Travel Power wasn’t providing enough power as the Victron input ampage limiter was set too low and the Victron was “topping up” the required amps, meaning the inverter was on with neutral/earth connected. I then turned up the ampage limit on the input to the Victron allowing the Travel Power to provide all of the power for the washing machine. The inverter then wasn’t required and neutral/earth was disconnected causing the Travel Power to blow up.

 

If this is the issue, then I’m not sure how to get around it as the only available setting is to stop neutral/earth connection altogether on the Victron. Unless the issue with the Travel Power is switching from one to the other during operation. Maybe it would be happy with neutral/earth disconnected if it was always that way?

 

It does say in the documentation about the Relay Flag - “Connection between N and PE during inverter operation. To permit use of a Residual Current Device (RCD). During operation as and inverter, a connection between PE and N is required.”

 

Anyway, first thing to try when the TP gets reinstalled is connecting directly to the washing machine without any link to the Victron. It will be "interesting" to see if this works.

[nb Innisfree]

Take care, as far as I can remember E/N link is disconnected whenever 230 ac is present on Victron input, irrespective of whether Victron switch is set to 'on' 'off' or 'charger'

Edited March 11, 2013 by nb Innisfree

[GUMPY]

As I said before just because it says NE link in the VE software doesnt mean that its there.

Check combi software version and do the physical check as I said earlier.

[Philippe]

But what about when 240v is being supplied but not enough for the demand so that power assist mode is activated and the inverter is working as well?

 

As I said before just because it says NE link in the VE software doesnt mean that its there.

Check combi software version and do the physical check as I said earlier.

 

Software version is 1802140 so I'm led to believe that the switch is there.

 

Will check this when everything wired up again, hopefully later this week.

Edited March 11, 2013 by Philippe

[nicknorman]

But what about when 240v is being supplied but not enough for the demand so that power assist mode is activated and the inverter is working as well?

 

 

 

Software version is 1802140 so I'm led to believe that the switch is there.

 

Will check this when everything wired up again, hopefully later this week.

With 3.5kw available from the TP (provided the engine is a little above idle) surely that is enough, therefore turn off power assist, UPS etc - ie all the things that might cause the Victron to start inverting whilst the TP is on.