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Regen under sail
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Hi all,? Very interesting discussions going on, thank you for your inputs. I was told that AC induction motors like mine are very bad /useless for regen. Would you agree? Aren't AC induction motors used in EVs with "relatively good" regen? Cheers Mich On Sat., 1 May 2021, 07:17 Randy Cain, <randylcain@...> wrote: Cycling through 4x series-connected 12v batteries will require a high current, isolated multiplexing circuit. The loss generated by the switching components will likely be as great a loss as a buck converter from 48v to 12v. And, the electrical noise introduced onto the DC bus will need to be handled because it will be pretty extreme since overlapping during the switch won't work due to the need to be isolated (so as not to get 24v when the circuit expected 12v). I recommend multiple smaller (~50a) buck conveters because they run nicely in parallel and can give you some redundancy. I run 4x 50a 96v to 12v converters on a main 12vdc bus and 4x 15a 96v to 12v converters on 4x isolated special purpose 12vdc busses. |
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Sailing Uma talked about this in one of their episodes. ? The problem is that you have to energize an AC motor which requires some draw on the system. Until the prop is spinning fast enough to generate net energy, regen isn't doing anything but depleting your bank. I think Dan had some crazy system where they ran the motor in reverse at a low draw to energize the motor and get the (folding) prop spinning, and then if the prop turned faster due to the motion of the boat through the water they'd get some regen. But I think they wrote the whole scheme off as not worth the effort. (This was on their original forklift motor, not their current saildrive). |
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I'm not familiar with regen with AC motors. But, on my boat with the 48 volt DC Thoosa 9000 system. I just move the forward control a little to say maybe a 10 amp draw which gives me a little forward speed in light winds and eliminates any prop drag. I then watch as the current goes down as the wind picks up until it finally switches positive and regens back to the battery. It's a beautiful thing to watch Mike BIANKA 1986 30U ?
On Saturday, May 1, 2021, 02:14:17 PM EDT, Ryan Scott Dancey <rsdancey@...> wrote:
Sailing Uma talked about this in one of their episodes. ? The problem is that you have to energize an AC motor which requires some draw on the system. Until the prop is spinning fast enough to generate net energy, regen isn't doing anything but depleting your bank. I think Dan had some crazy system where they ran the motor in reverse at a low draw to energize the motor and get the (folding) prop spinning, and then if the prop turned faster due to the motion of the boat through the water they'd get some regen. But I think they wrote the whole scheme off as not worth the effort. (This was on their original forklift motor, not their current saildrive). |