xp677 wrote: ↑Fri May 22, 2020 9:04 pm
You can also just send a PWM signal to them (this is essentially what the economiser does). Start at 100% and then drop it to whatever keeps it closed.
Of course you need a suitable circuit to drive the coil. Best to keep the economiser. I run Kilovac contactors (with economiser), with a 10A relay to trigger them. The code above is used as an economiser for the 10A relay.
I'm barely understand this programming thing. Also contactor in this board activates true BTS117. Are they capable of handling PWM signal? Won't they overheat? I'll better solder those economisers back.
Most contactors require economizer functionality to minimise power consumption in the coil. This can be built into the contactor, an external circuit, or via software/hardware in the controller.
AFAIK none of the Open Inverter boards support software/hardware economizer functionality directly (they're just simple switched outputs) and therefore you need to implement this yourself with an external board or use a contactor that has the functionality built in.
This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
Kevin Sharpe wrote: ↑Sat May 23, 2020 11:08 am
AFAIK none of the Open Inverter boards support software/hardware economizer functionality directly (they're just simple switched outputs) and therefore you need to implement this yourself with an external board or use a contactor that has the functionality built in.
I used to program Curtis inverter and that guy wasn't happy about economiser. There are parameters as pull in and hold voltages, it also detects any failure within any circuit. Really bullet-proof design as it turns out=)
Kevin Sharpe wrote: ↑Sat May 23, 2020 11:08 am
AFAIK none of the Open Inverter boards support software/hardware economizer functionality directly (they're just simple switched outputs) and therefore you need to implement this yourself with an external board or use a contactor that has the functionality built in.
I used to program Curtis inverter and that guy wasn't happy about economiser. There are parameters as pull in and hold voltages, it also detects any failure within any circuit. Really bullet-proof design as it turns out=)
The great thing about open source is that you can change anything you want. Indeed, Damien and Johannes are using different contactor driver chips iirc. My approach is to use contactors with built in economizers and that's something we recommend on our courses
This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
BTS117 contains a load of extra components for the various protection measures, not sure how it would handle PWM, I imagine it would depend on your switching frequency.
The economisers which come with the Kilovac contactors are best suited for the job.
I was advised (probably in another thread on this forum) not to use transistor-based switching for the power input to the economisers on these contactors. Which is why I used a small relay.
The PWM code above is just there to reduce the power consumption of that relay. It reduced the relays coil power by about 1W, which is a good result for just a few lines of code.
xp677 wrote: ↑Sat May 23, 2020 12:18 pm
The PWM code above is just there to reduce the power consumption of that relay. It reduced the relays coil power by about 1W, which is a good result for just a few lines of code.
Just to be clear, was that code tested on non modified open inverter hardware and if so which boards?
This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
I'm struggling to find one of the commonly used Panasonic relays from the Leaf or Ampera for the precharge on my project - at least at what feels like a sensible price. Mostly £30-40 used from China. Is there any reason I couldn't use something like this? Not much more and it has the advantage of being new: https://uk.rs-online.com/web/p/solid-st ... s/0352496/
Those are only suitable for AC. The nature of these units is that once triggered, they remain on until the current falls to zero. in a DC application, this would make them impossible to turn off. This is what they mean by "zero crossing", they turn off as the AC waveform crosses zero.
One example of use for these SSRs is for intensity control (dimming) of high powered resistive lamps. If you trigger them with a pulse, they will remain on for the remainder of the AC half-cycle. Thus the power transferred is the area under the curve.
I used the EV200 contactors for my precharge - overkill for the application, but they are available second hand at reasonable cost.
DC-rated switchgear will always be more complex and expensive compared to that designed for AC, as any arc created during an opening event will not self-extinguish. Features such as arc chutes, vacuum chambers, plated contacts, magnets, etc are added to higher voltage DC rated contactors to help extinguish this arc. Also remember when installing them that they are often polarity-sensitive.
I have a bunch of the 800VDC/100A rated small contactors up for sale here: viewtopic.php?f=12&t=712 if you can switch off after pre-charge is complete you don't even need an economiser.
xp677 wrote: ↑Wed May 27, 2020 9:17 pm
Those are only suitable for AC. The nature of these units is that once triggered, they remain on until the current falls to zero. in a DC application, this would make them impossible to turn off. This is what they mean by "zero crossing", they turn off as the AC waveform crosses zero.
One example of use for these SSRs is for intensity control (dimming) of high powered resistive lamps. If you trigger them with a pulse, they will remain on for the remainder of the AC half-cycle. Thus the power transferred is the area under the curve.
I used the EV200 contactors for my precharge - overkill for the application, but they are available second hand at reasonable cost.
DC-rated switchgear will always be more complex and expensive compared to that designed for AC, as any arc created during an opening event will not self-extinguish. Features such as arc chutes, vacuum chambers, plated contacts, magnets, etc are added to higher voltage DC rated contactors to help extinguish this arc. Also remember when installing them that they are often polarity-sensitive.
Thank you. Really useful answer. Learning a lot here!
jnsaff wrote: ↑Thu May 28, 2020 7:29 am
I have a bunch of the 800VDC/100A rated small contactors up for sale here: viewtopic.php?f=12&t=712 if you can switch off after pre-charge is complete you don't even need an economiser.
Thank you. Already have a couple of contactors on their way from you! Will let you know on these.
xp677 wrote: ↑Wed May 27, 2020 9:17 pm
Those are only suitable for AC. The nature of these units is that once triggered, they remain on until the current falls to zero. in a DC application, this would make them impossible to turn off.
In a precharge application, the current would drop to zero once the main contactor closed. However the leakage current can be a problem.
I've used SCRs in series with relays. The relay contacts are closed under zero current conditions and then the SCR is triggered.
xp677 wrote: ↑Wed May 27, 2020 9:17 pm
Those are only suitable for AC. The nature of these units is that once triggered, they remain on until the current falls to zero. in a DC application, this would make them impossible to turn off.
In a precharge application, the current would drop to zero once the main contactor closed. However the leakage current can be a problem.
I've used SCRs in series with relays. The relay contacts are closed under zero current conditions and then the SCR is triggered.
In an ideal world, yes. However this would rely on the leakage being low enough to allow the SCR to open, and would necessitate the precharge completing with the "main" contactor closing (imagine if you turned the ignition key to "OFF" mid-precharge, for example).
Such events could perhaps be solved with logic (for example, opening a separate contactor elsewhere in the chain) and component choice, but the fact remains that components would have been chosen which are unsuited to the task at hand.
bobby_come_lately wrote: ↑Wed May 27, 2020 12:27 pm
I'm struggling to find one of the commonly used Panasonic relays from the Leaf or Ampera for the precharge on my project - at least at what feels like a sensible price. Mostly £30-40 used from China. Is there any reason I couldn't use something like this? Not much more and it has the advantage of being new: https://uk.rs-online.com/web/p/solid-st ... s/0352496/
I have used AEV52012 from Nissan Leaf in a lot of applications. It is really a good small relay for HV. Dont make a mistake, it is not a contactor. It can release up to 20A. As i presented it in the beginning of this thread you can get it for like $40 or so with shipping. I consider this a fair price. https://www.ebay.co.uk/itm/FedEx-DHL-ON ... SwnhFeeaCP
It has two magnets under silver contacts which pull down arc discharge before it fully forms.
Also i tried to use it for heater control and it worked ok. You need to keep the amps low though and use PWM so it doesnt release under full power.
I tried to use SSRs, even the mosfet version and they failed miserably when releasing under power. Dont reccomend them above 120Vdc.
I've gone ahead and ordered an AEV52012 but only place I could find one at that price was from China so it's going to take a few weeks to arrive. Surprised no UK breakers seemed to be selling them. Might have to get friendly with a local scrap yard. Miss the old days when you could just roam around and pay on the way out. If anyone knows of a yard like that in Manchester... Guessing health and safety might rule it out though.
Hi,
I'm not super happy with the stock HV cables for the LDU from Tesla, and am considering building my own bespoke cables, but there are some bit's I don't know how to source, or even what they are called. They are the connectors/Shielding terminators in the attached photos.
Hank wrote: ↑Thu Jun 04, 2020 6:24 pm
Any help would be appreciated.
I tried searching for terms like coroplast, screen termination, ferrule, HV crimp, etc., but didn't find anything useful
This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
Alrighty then....$20 Amazon gift card to the first person who can accurately help me source these little buggers for use on my project.
This is driving my crazy, and I'm 90% sure these are available off the shelf somewhere.
Hank wrote: ↑Mon Jun 15, 2020 4:23 pm
Thanks for the tip, couldn't find anything, but did get some good search terms.
Anyone else?
I'm still looking for the crimps. In the meantime I did find this;
This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
I have a similar problem, I need longer cables on the motor. My 70mm² cable has a larger outer diameter than the AWG 2/0. I will make stainless steel parts to make it fit.
Just got confirmation from Zero-EV that they expect to have these available in the next couple of weeks.
I'm on the notification list, very excited about this. Thanks @Tom91, appreciate it!
