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Ericson 41 with electric motor driven by FS 75200

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Svein Utne
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Ericson 41 with electric motor driven by FS 75200

Hi,

My goal is to put a 10 KW motor 100V and 100A in the sailboat. I have tried several controllers, but I might have to upgrade the controller soon.

I am still waiting for the batteries to arrive from China, so in the waiting face I wanted to see if I could make the motor turn with only 4s LiFeO4 with only 14ah that I got laying here. I run it sensor less, and it is turning, but very strangely. I guess it takes 30 amps just to turn the motor, so maybe the BMS shuts the power off, or the ESC controller senses the drop in voltage and cuts the power. It run for 1 second, then cut of for one second, so the motor starts and run up til 100rpm, and stops and up again. 

If I turn the speed potentiometer further up, it stops completely. It only runs when the pot is just starting to start the motor. I guess this is a problem that will go away when I get more batteries or not?

I just found this problem on the forum, and it looks to be close to what I got? https://vesc-project.com/node/3407

I also noticed the Flipsky 75100 started to get warm, an this was under no load. So I ordered the Flipsky 75200 with water cooling. I also ordered the waterproof remote controller for it. Then I found the Tronic 250R that can handle more than 100V. I have not ordered it yet. I want to see how Flipsky 75200 is working first. Also I wonder if the remote controller I ordered with the Flipsky will work with the Tronic 250R.

I was planing to install a sensor on the motor, but I wonder if the VESC software is so good that it will run just fine sensor less?

As you see I have a lot of questions, so if some of you got some answers fell free to comment.

Regards

Svein Utne

frank
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Hi Svein, please note that non of the Flipsky controllers can deal with 100V. You always need a good portion voltage margin because of voltage spikes and inductance of the wires causing spikes.

So stay well below the rated voltage! Flipsky is third party stuff and they should give you the support you need to turn that motor. Software and HW interacts and the results can differ from HW to HW.

Svein Utne
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Yes, I know the Flipsky is only for 75 or 84 Volts, so I will only get 50% power from the motor in this first test phase. If I then go for a Tronic 250R and finely ends up with a TRAMPA VESC 100/250 I did not save any money. Maybe Trampa can then use me as an example how not to buy a cheap Chines controller.

I am new to this, so I do not know the market, but from what I have found so far, the price of the controller increase drastically when one go above 100 volt. The motor I got is rated for 100 volt, but can be pushed till 120 volt for a short time, as long as one manage to cool it. Its weight is above 30 kg. The battery pack I plan to use is not so large, about 20kwh, but if I run it at moderate speed it will be OK I hope. Time will tell, and also if I manage to regenerate power while under sail. So for me the ideal controller should be able to handle 120 volt and 150 Amp with out getting to warm.

When I have looked the price jump from 2-400  till 800 USD when going from 80 till 110 volt. 

If someone that know the market can recommend a controller with high quality and reasonable price. The weight is not so important. The sailboat weigh more than 9 ton, so some kg extra is no problem.

Looking forward for some recommendations.

 

frank
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100V Mosfets have around 3-5 times less resistance. The best 100V Fets have 1.2mOhm, the typical 150V Fets are around 9mOm.  So you need a lot more mosfets and dual gate drivers and good 150V+ rated voltage regulators are also not very available. Conclusion: if you go above 100V make sure to go all the way up to 140V and accept that the controller gets big and expensive. If you only surpass the 100V slightly, you will deal with all the downsides of the 150V Fets and gain little on the other hand side. So it is best to stay at 22S max in most cases. If you have little bit of patience you, your waiting time will pay out....

Svein Utne
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Thank you Frank. What you say makes a lot of seance. This summer I will only be in the fjord close to my home town Trondheim, so maybe the FS 75/200 will be enough, but next summer I was planing on a longer trip. I liked you last sentence. It gave me some hope.

Frank, I have been thinking on your last sentence. What is coming soon? Is it Gallium Nitride or Silicon carbide technology you are thinking of or just some improvements of the MOSFET?