Hi All,
My first post, so please forgive any faux-pas ( and correct me to what I should have done ) but I thought I'd introduce my project - It's an Electric-X ( Extended Range ) bicycle project. It combines an battery-electric system with a small generator that has the throttle controlled based on the load being presented to it, so it can charge the battery during use of the bicycle, so it's not technically a hybrid, which allows both petrol and electric motors - it's an Electric-Extended system.
I started with a cheap $80 bicycle that was already about a decade old, and began rebuilding it into what I need to test/develop my project.
OK, you can laugh... I does work though.
I've made a few daft mistakes already- and screwed up the output power from the battery-electric system - it's putting out around 130w at the moment, when I really want 200w ( I'm in Australia, so have to keep within local rules ) but that aside, it's only a platform for the extended system I'm playing with - And I intend to tweak the voltage as required anyway... Hopefully that will fix the issues.
The extended system contains a number of components - First, I've mated a 300w DC brushed generator to a 33cc petrol 4-stroke motor to provide the power - it's all COTS parts, except the couples and shafts, which are all custom-3D printed, and currently made of plastic ( and enhanced by metal components ).
This provides the power which is filtered by a rectifier and a LC circuit with a fairly large choke and a very solid capacitive array with over 20A RMS ripple current rating. It's not perfect for direct drive of sensitive electronics, but is more than suited to the battery charge requirements and the down-converters and charge controllers for different applications - The whole system should work with brushless as well, up to about 1.5kW, though the motor tops out at 1.2 and I have designed this one to run at 800W maximum, 300W continuous.
It's all still bench testing, except the bicycle, which did actually ride, but the rear rack I got to install the system was bent, and it takes several weeks for a new one to arrive -
Overall, voltage and power regulation comes from the autothrottle, which forms a wide-closed-loop system, using the capacitors and battery as a buffer and adjusts the motor output as necessary. This took a while to develop and uses 3D printed parts also - it's fairly quick and can keep the voltage within +1/-2v of the setting, though has been intended to work with a wide hysteresis value to avoid hunting. Still, it's quick enough that I can start the engine on WOT ( Wide open throttle ) and it will respond within a few 10ths of a second to drop it back to the correct power setting before it has a chance to over-current the batteries, so it seems pretty solid, though I'll include a "motor running" detector in future circuits to close the throttle automatically if the motor shuts down before the circuitry is disengages.
Well, it's still coming along, but the motor and controls can respond to a 250w load coming online instantly, with the engine throttling up as soon as the battery voltage begins to drop and supplying the power needed. It will also maintain suitable float voltages to maintain the batteries even at extended idle ( I usually set so float voltage is around 27~28v at very low power... ) - So the current version is suited to direct connect however later prototypes will include a charge/load controller and boost/buck circuit so I can run batteries at any voltage with any generator combination, and also have direct input capability for PV cells as well - since that will maintain charge and operation when the motor is off.
Overall, it doesn't look that impressive, but all the parts seem to work correctly and I'm hoping to start riding it around in about a month or so - perhaps to and from work. I'm aiming for 140km/liter of fuel, so the small included tank should get me 30km and back easy enough - Also, that will possibly make it one of the first practical road-legal super-low consumption vehicles around, but then again I'm new to this, so perhaps they are already everywhere and I'm just not noticing it. It does support automatic starting, so I could include an autostop when the power drops below 10w for more than a few seconds, meaning it would be good for traffic too -
The small cycles for the battery should be good as well - and I'm hoping a single set of batteries will last the bike's lifetime - since it can cope with a lot of capacity loss as the batteries are constantly being charged/protected from load by the petrol engine.
So, as the project progresses, I'm interested in what people think, any suggestions you can help with ( Most of the problems with this idea I have been finding in the same way you find furniture in a dark room ) and any suggestions regarding features I should include ( yes, I will be including USB output for my phone... But suggestions for good lights for the bike, at 12v or 24v, or the likes are greatly appreciated. )
Current status - Running and operational on the test bench - Just waiting to get a good rear-rack ( quick mount/dismount as the bicycle electrical system will remain on the bike - this is for a smart petrol-engine based charger with the capacity of around 300w continuous )
My first post, so please forgive any faux-pas ( and correct me to what I should have done ) but I thought I'd introduce my project - It's an Electric-X ( Extended Range ) bicycle project. It combines an battery-electric system with a small generator that has the throttle controlled based on the load being presented to it, so it can charge the battery during use of the bicycle, so it's not technically a hybrid, which allows both petrol and electric motors - it's an Electric-Extended system.
I started with a cheap $80 bicycle that was already about a decade old, and began rebuilding it into what I need to test/develop my project.
OK, you can laugh... I does work though.
I've made a few daft mistakes already- and screwed up the output power from the battery-electric system - it's putting out around 130w at the moment, when I really want 200w ( I'm in Australia, so have to keep within local rules ) but that aside, it's only a platform for the extended system I'm playing with - And I intend to tweak the voltage as required anyway... Hopefully that will fix the issues.
The extended system contains a number of components - First, I've mated a 300w DC brushed generator to a 33cc petrol 4-stroke motor to provide the power - it's all COTS parts, except the couples and shafts, which are all custom-3D printed, and currently made of plastic ( and enhanced by metal components ).
This provides the power which is filtered by a rectifier and a LC circuit with a fairly large choke and a very solid capacitive array with over 20A RMS ripple current rating. It's not perfect for direct drive of sensitive electronics, but is more than suited to the battery charge requirements and the down-converters and charge controllers for different applications - The whole system should work with brushless as well, up to about 1.5kW, though the motor tops out at 1.2 and I have designed this one to run at 800W maximum, 300W continuous.
It's all still bench testing, except the bicycle, which did actually ride, but the rear rack I got to install the system was bent, and it takes several weeks for a new one to arrive -
Overall, voltage and power regulation comes from the autothrottle, which forms a wide-closed-loop system, using the capacitors and battery as a buffer and adjusts the motor output as necessary. This took a while to develop and uses 3D printed parts also - it's fairly quick and can keep the voltage within +1/-2v of the setting, though has been intended to work with a wide hysteresis value to avoid hunting. Still, it's quick enough that I can start the engine on WOT ( Wide open throttle ) and it will respond within a few 10ths of a second to drop it back to the correct power setting before it has a chance to over-current the batteries, so it seems pretty solid, though I'll include a "motor running" detector in future circuits to close the throttle automatically if the motor shuts down before the circuitry is disengages.
Well, it's still coming along, but the motor and controls can respond to a 250w load coming online instantly, with the engine throttling up as soon as the battery voltage begins to drop and supplying the power needed. It will also maintain suitable float voltages to maintain the batteries even at extended idle ( I usually set so float voltage is around 27~28v at very low power... ) - So the current version is suited to direct connect however later prototypes will include a charge/load controller and boost/buck circuit so I can run batteries at any voltage with any generator combination, and also have direct input capability for PV cells as well - since that will maintain charge and operation when the motor is off.
Overall, it doesn't look that impressive, but all the parts seem to work correctly and I'm hoping to start riding it around in about a month or so - perhaps to and from work. I'm aiming for 140km/liter of fuel, so the small included tank should get me 30km and back easy enough - Also, that will possibly make it one of the first practical road-legal super-low consumption vehicles around, but then again I'm new to this, so perhaps they are already everywhere and I'm just not noticing it. It does support automatic starting, so I could include an autostop when the power drops below 10w for more than a few seconds, meaning it would be good for traffic too -
The small cycles for the battery should be good as well - and I'm hoping a single set of batteries will last the bike's lifetime - since it can cope with a lot of capacity loss as the batteries are constantly being charged/protected from load by the petrol engine.
So, as the project progresses, I'm interested in what people think, any suggestions you can help with ( Most of the problems with this idea I have been finding in the same way you find furniture in a dark room ) and any suggestions regarding features I should include ( yes, I will be including USB output for my phone...
But suggestions for good lights for the bike, at 12v or 24v, or the likes are greatly appreciated. )Current status - Running and operational on the test bench - Just waiting to get a good rear-rack ( quick mount/dismount as the bicycle electrical system will remain on the bike - this is for a smart petrol-engine based charger with the capacity of around 300w continuous )
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