This year has been very busy with work and house renovations, unfortunately it's taking time away from the bike project. I have updated the schematic and sourced a better suited IGBT for the drivers and added some on board capacitance after some good feedback(thanks Will). I am just setting up my subversion server and an ftp server here so that I can host the project files a bit easier.
I have setup a workbench and purchased some steel to make up the motor brackets. I am just saving some money for the batteries and components for the motor controller. I have made up a small low power encoder(this is a for another project) which will be able to detect motor direction and speed. It will have 2 encoder counts per revolution.
So the todo list ATM is:
- Purchase battery's and battery charger
- Make motor brackets
- Make battery cradle
- Extend chain by 2 links
- Make and test motor controller(lot of work here, build prototype and write software)
Friday, March 6, 2009
Wednesday, January 14, 2009
I have now completed the initial schematic for the 3-phase motor controller. I have to update some footprints and then it will be time to start on laying out the PCB. You can download stuff from here
Schematic PDF
gEDA project
gEDA symbols
The schematic is done on gEDA, the PCB will be done on PCB the PCB editor that is part of the gEDA package. The software will be written for avr-gcc. Both gEDA and the c complier are open source projects, and very good at what they do. Currently gEDA only works under Linux, but the compiler will work under windows with wan-avr(Just a side note I am designing and writing all the software for this project on a asus eee 901 with gentoo installed on it, a fantastic piece of hardware).
To get the gEDA project to run you need gEDA suite installed, uncompress the project and uncompress thje symbols. You need to make the gschem point to the schematic symbols directory. To do this you can simply uncompress the symbols tar into your linux home directory and everything should work. Otherwise you could just copy everything in the /lib/schematic directory into the /hardware/mc directory. Otherwise have a look in /hardware/commonrc and update/add the schematic directory to the component directories. One this is done change directory to the /hardware/mc directory and run make edit, this will open gschem. Have a look in /hardware/makefile for a list of other things you can use make to do.
Please if you do know anything about 3-phase motor control I would appreciate any feedback on the design, and I will post updates and corrections as I make them.
Schematic PDF
gEDA project
gEDA symbols
The schematic is done on gEDA, the PCB will be done on PCB the PCB editor that is part of the gEDA package. The software will be written for avr-gcc. Both gEDA and the c complier are open source projects, and very good at what they do. Currently gEDA only works under Linux, but the compiler will work under windows with wan-avr(Just a side note I am designing and writing all the software for this project on a asus eee 901 with gentoo installed on it, a fantastic piece of hardware).
To get the gEDA project to run you need gEDA suite installed, uncompress the project and uncompress thje symbols. You need to make the gschem point to the schematic symbols directory. To do this you can simply uncompress the symbols tar into your linux home directory and everything should work. Otherwise you could just copy everything in the /lib/schematic directory into the /hardware/mc directory. Otherwise have a look in /hardware/commonrc and update/add the schematic directory to the component directories. One this is done change directory to the /hardware/mc directory and run make edit, this will open gschem. Have a look in /hardware/makefile for a list of other things you can use make to do.
Please if you do know anything about 3-phase motor control I would appreciate any feedback on the design, and I will post updates and corrections as I make them.
Tuesday, January 6, 2009
Motor controller and batteries
I have got caught up over the holiday doing stuff on the house, but I have been researching and drawing up the schematics for the motor controller on gEDA. The first draft of the schematic is about 80% complete and I have layed out the components, I just need to do some tweeking and adding in component details(resistor and cap specs etc). I hope to have to up within the week for comments/feedback.
I am now looking at getting 18 of the EVH15120. These are a comprimise between price and performance. Since they are designed for EV use they should last a while, they will fit into the frame of the bike, and there not too heavy. The upside is there easy to get and at least half the price of Lithium. The downside will be the weight and the charge time.
I have attached the LED blinkers to the bike and here is a pic.
And the back...
I have bought some workshop equipment that will help me with the fabrication of the batttery case/tray and motor mounting brackets etc. I have got most of the electronic components that I need to build the controller too.
I am now looking at getting 18 of the EVH15120. These are a comprimise between price and performance. Since they are designed for EV use they should last a while, they will fit into the frame of the bike, and there not too heavy. The upside is there easy to get and at least half the price of Lithium. The downside will be the weight and the charge time.
I have attached the LED blinkers to the bike and here is a pic.
And the back...
I have bought some workshop equipment that will help me with the fabrication of the batttery case/tray and motor mounting brackets etc. I have got most of the electronic components that I need to build the controller too.
Thursday, December 4, 2008
Indicators, Grips and the Motor
I have been getting quite motivated lately to get some work done on the bike. I have just received some led blinkers. I have ordered the 0-5v hall effect twist grip throttle that should be arriving tomorrow. I have done some more research on Mosfets and IGBT's for the motor controller. At the moment I am leaning toward a 600V IGBT. I am switching 360V which is a little on the high side for mosfets, and there are some quite quick IGBT's. I am about to start the schematic for the motor controller.
The good news is that I have finally cracked open my 3kw 3 phase induction motor and had a peak at modifying the wiring to half the voltage I need to drive the motor with. I started by cutting the tape holding the wiring together and numbering each slot. The motor is a 4 pole motor with 36 slots. This gives me 12 slots per phase,and each slot is paired to make 6 coils per phase. There are the 6 wires coming into the motor and 9 wires that jump between coils. After writing all this down I then had to work out what it meant and what I have to cut to take the 6 in-series coils in half to get 2 3 in-series coils and run them in parrallel to get half the voltage. I figured out that each phase has 3 slots next to each other and then the next phase has 3, then the next and so on. This give me 4 sets of 3 slots per phase which is where the 4 pole comes from. So I have found the 3 wires I need to cut to halve the voltage. Yay!!!
The good news is that I have finally cracked open my 3kw 3 phase induction motor and had a peak at modifying the wiring to half the voltage I need to drive the motor with. I started by cutting the tape holding the wiring together and numbering each slot. The motor is a 4 pole motor with 36 slots. This gives me 12 slots per phase,and each slot is paired to make 6 coils per phase. There are the 6 wires coming into the motor and 9 wires that jump between coils. After writing all this down I then had to work out what it meant and what I have to cut to take the 6 in-series coils in half to get 2 3 in-series coils and run them in parrallel to get half the voltage. I figured out that each phase has 3 slots next to each other and then the next phase has 3, then the next and so on. This give me 4 sets of 3 slots per phase which is where the 4 pole comes from. So I have found the 3 wires I need to cut to halve the voltage. Yay!!!
Monday, November 24, 2008
Update On Battery Pack
After a long break I am looking at getting back into the bike conversion (been very busy with work and family). I am itching for a ride everytime I see the dust covered Across. I have re-evaluated the battery pack and after seeing some other conversions and considering the cost of the lithium batteries. I am now looking at a 336VDC @ 7AH battery pack. This will be either gel or SLA for cost purposes to begin with and then upgraded to a lighter and higher powered lithium pack if all goes well.
Running the battery pack at this voltage will allow for a simpler 3-phase motor controller since I won't have to increase the voltage. I can simply use PWM to lower the voltage and frequency to the required levels. The motor will be run in delta configuration which requires 230V AC and then re-connect each of the windings so that I run them in parallel not series so this will end up requiring ~120VAC which is about 340Vp-p and within the battery pack voltage.
Running the battery pack at this voltage will allow for a simpler 3-phase motor controller since I won't have to increase the voltage. I can simply use PWM to lower the voltage and frequency to the required levels. The motor will be run in delta configuration which requires 230V AC and then re-connect each of the windings so that I run them in parallel not series so this will end up requiring ~120VAC which is about 340Vp-p and within the battery pack voltage.
Thursday, November 22, 2007
The Battery Pack
After much investigation I have come to the conclusion that lithium rechargeable battery's are the battery of choice. They are the best value for money in terms of power to weight ratio. I have to keep the bike somewhere in the original weight range to get it registered, and i also want the bike to have as great a range as possible with the latest technology available. I am looking a making a battery pack consisting of 40 3.2V 40A lithium battery's that weight about 1.5kg each. So that gives me a total battery pack with a nominal voltage of 128V at 40A and a weight of 60kg. This works out to be a ~5kw battery pack. So it should run the 3kw motor for at least 1.5 hours.
I am going to make 40 fake batteries of the same dimensions that i am looking at using to make sure i can physically fit them in the bike. I have the leftover room where the electric motor is and petrol motor was, i also have some room up front near the headlight that I may be able to squeeze a few in and also where the air-cleaner was and of course under the seat where the petrol tank used to be. I also have to be careful to leave enough room for the battery charger and motor inverter.
I am going to make 40 fake batteries of the same dimensions that i am looking at using to make sure i can physically fit them in the bike. I have the leftover room where the electric motor is and petrol motor was, i also have some room up front near the headlight that I may be able to squeeze a few in and also where the air-cleaner was and of course under the seat where the petrol tank used to be. I also have to be careful to leave enough room for the battery charger and motor inverter.
Wednesday, October 3, 2007
3-Phase Motor
I have now got the electric motor. It is a 3-phase induction motor by CMG. I have had a cog machined up to fit onto the shaft of the motor. The motor will sit in the frame with the cog slightly forward of the original gearbox output, so i have to extend the chain by 3 links. I have had some motor mounting brackets made but they need some modification (the chain sits on the swingarm at the moment).
The motor is designed to take 380V-415v at 50Hz in star configuration. It is a 4-Pole motor and the speed of the motor when supplied with this is ~1425RPM at 82% efficiency. I am looking at running the motor in delta configuration which is 220V-240V at 50Hz, the efficiency is still 82%. Because the motor is actually 4-pole. I should be able to hopefully (this depends on how the motor is wound) make a modification inside to change the poles so that instead of in serial they are parallel. This will then bring the motor voltage into the 110V-120V range. Which is about the voltage of the battery pack that I'm planning on using. If i can do this it will simplify the inverter design.
I have also painted and fitted the mirrors.
The motor is designed to take 380V-415v at 50Hz in star configuration. It is a 4-Pole motor and the speed of the motor when supplied with this is ~1425RPM at 82% efficiency. I am looking at running the motor in delta configuration which is 220V-240V at 50Hz, the efficiency is still 82%. Because the motor is actually 4-pole. I should be able to hopefully (this depends on how the motor is wound) make a modification inside to change the poles so that instead of in serial they are parallel. This will then bring the motor voltage into the 110V-120V range. Which is about the voltage of the battery pack that I'm planning on using. If i can do this it will simplify the inverter design.
I have also painted and fitted the mirrors.
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