What about the 11" Kostov neutrally-timed, interpoled, series-wound motors?
Adding Regen to DC? Not for range...
I live in the foothills of SoCal and I notice that while I drive any of my ICE vehicles, auto or stick, I use downshifting to control my speed. I do this for traffic or hills. Since I am seriously considering a DC electric conversion, I would like some resistance from the drivetrain when operating under zero throttle. I would use the transmission to select the amount of drag, lower gears for more deceleration, just the same as the ICE vehicles. My intended pack voltage will probably be 156V (48 lithium cells). I know that a controller will be needed to prevent overcharging, the max regen (charging) voltage should be no higher than 168V - 170V.
Since I typically care about efficiency, I don't want to just drag the brakes all the way downhill or approaching a traffic signal (I don't do that today in my Suburban, Fit, Insight or 914-V8). So for the sake of driveability, how can I get the conversion to feel more like a regular car? I'm not impressed with the AC systems that are available today, none seem to match the power of a WarP9 for a similar weight.
I've spent a day reading way too many threads that barely touch on the subject (please don't mention perpetual motion) and the only practical advice that I mined from all that has been the guy with the S-10 that rewound his own alternator. I was hoping that I could buy most of the components necessary to build a similar finished product. I'm not looking for a kit, just some sources for the major components. I'm also open to alternative strategies. Anybody else headed down this path before?
Thanks,
Eric
Since I typically care about efficiency, I don't want to just drag the brakes all the way downhill or approaching a traffic signal (I don't do that today in my Suburban, Fit, Insight or 914-V8). So for the sake of driveability, how can I get the conversion to feel more like a regular car? I'm not impressed with the AC systems that are available today, none seem to match the power of a WarP9 for a similar weight.
I've spent a day reading way too many threads that barely touch on the subject (please don't mention perpetual motion) and the only practical advice that I mined from all that has been the guy with the S-10 that rewound his own alternator. I was hoping that I could buy most of the components necessary to build a similar finished product. I'm not looking for a kit, just some sources for the major components. I'm also open to alternative strategies. Anybody else headed down this path before?
Thanks,
Eric
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That motor can do regen. Not a lot of vehicles use such large DC motors so there are not very many series DC motor controllers designed to offer regen.What about the 11" Kostov neutrally-timed, interpoled, series-wound motors?
I do love my systemJust a suggestion, but have you considered dropping your system low enough to run a sepex or AC motor like JRP3? His Fiero has fully functioning regen setup and seems to have enough pow - well, I'll let him tell you how it runs
Just put it in second gear and go, all the way to 65 mph. Doesn't have the off the line pull of a DC series motor but it's plenty for normal driving, and there is always first gear if I want a quick shot from 0-35 mph.
My take is that this isn't terribly practical for two reasons:I live in the foothills of SoCal and I notice that while I drive any of my ICE vehicles, auto or stick, I use downshifting to control my speed.
...the only practical advice that I mined from all that has been the guy with the S-10 that rewound his own alternator.
...
1. The average automotive alternator is ~1kW in size and about 50% efficient (typical "claw pole" design) and that power capability applies no matter what voltage you re-wind it for. This means you can develop a maximum of about 2kW of braking power with the average alternator.
2. 2kW of braking power, alone, can decelerate a 1000kg vehicle from 60mph to 0 in about 138 seconds. My guess is you would barely notice the difference between that rate of deceleration and simply coasting.
Well, how about two Automotive alts on the rear wheels?
You could have them charge the batteries directly using maybe a diode bank, if using 12v batts.
Also, you can change the voltage output by controlling the voltage input. Build a new voltage regulator that can charge at the whole pack voltage
You could have them charge the batteries directly using maybe a diode bank, if using 12v batts.
Also, you can change the voltage output by controlling the voltage input. Build a new voltage regulator that can charge at the whole pack voltage
IMHO the highest gear ratio that the alternator can use without damaging it by over spinning would be desired in order to multiply the braking force. An average ice alternator is geared at around 3:1 X 3.5 final drive ratio equals >10:1 So wouldn't 1kw of stopping force also be multiplied by 10? I realize it would be less as the vehicle speed is reduced.
That raises an interesting question, how much decelerative hp comes from a regular 4 cylinder engine at zero throttle? In my experience, not that much, certainly way less than our Insight in it's regen mode. Since 2 minutes sounds about right for my car to coast down from 60mph on level ground in neutral, 2kW added to the regular coasting drag may be close to what a ICE adds (subtracts?), i.e. slowing down twice as fast.My take is that this isn't terribly practical for two reasons:
1. The average automotive alternator is ~1kW in size and about 50% efficient (typical "claw pole" design) and that power capability applies no matter what voltage you re-wind it for. This means you can develop a maximum of about 2kW of braking power with the average alternator.
2. 2kW of braking power, alone, can decelerate a 1000kg vehicle from 60mph to 0 in about 138 seconds. My guess is you would barely notice the difference between that rate of deceleration and simply coasting.
That said, after evaluating how much braking would actually be needed during my regular commute without engine decel (shifting into neutral every time I lifted my foot off the throttle), I find that I had over-estimated the amount of braking that a regular DC conversion would require. So unless the regen for driveability solution is both cheap and easy, it won't make it onto the build list.
Eric
ICE deceleration depends on what gear you're in... Certainly, you won't feel much if you're coasting down in fifth or sixth, but the engine compression braking in first and second is very noticeable. Remember, it's safer (with an ICE car) to coast down a mountain pass in a lower gear than ride the brakes in a higher gear.
It would also seem that electric regen would be able to provide a constant level of deceleration, while an ICE's compression deceleration diminishes with engine speed.
It would also seem that electric regen would be able to provide a constant level of deceleration, while an ICE's compression deceleration diminishes with engine speed.
EV deceleration is also gear dependent, you won't get much in 4th or 5th, another reason I do most of my driving in second. The nice thing about regen is the way you can modulate the intensity with the accelerator pedal. I can hold the pedal neutral for zero regen and coast, or I can use varying amounts of regen depending on what I need. Takes a little getting used to and some practice but I like it. Adds another dimension to driving.
Yes... I'd love for the Soliton-1 to be able to provide regen with my neutrally-timed, interpoled-Kostov (hint, hint ). As it stands I have to rely on drum brakes designed in the fifties to slow an SUV (a small SUV, granted). Or... figure out how to engineer disc brakes on... it's possible.
). As it stands I have to rely on drum brakes designed in the fifties to slow an SUV (a small SUV, granted). Or... figure out how to engineer disc brakes on... it's possible.Takes a little getting used to and some practice but I like it. Adds another dimension to driving.
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