Tischer's EV project
Updates
My chassis
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| 2008-06-14 I bought a 2001 VW Passat with a siezed cam on Craigslist for $1800. It even has a full tank of gas! The trunk and engine compartment are nice and roomy, which is great for carrying lots of batteries. Curb weight is 3141 lbs and GVWR is 4322 lbs. The cast iron engine, automatic transmission, exhaust and gas tank should free up a good 600lbs leaving me 1800 lbs to work with. Drag (Cd) is a very low 0.27; this is less drag than a 2006 Corvette, 2006 Civic, and a 2001 Prius. Landy didn't struggle too bad towing it home, she even got 14 MPG! |
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| 2008-06-14 Heated leather seats and sun roof! Germans know a thing or two about making a beautiful interior. |
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I plan to install a manual transmission. I will use the automatic shifter mechanism with the manual transmission to select 1st gear, 2nd gear and Neutral. If I decide to get creative, I will try for 2nd and 3rd gear selection instead; this requires more than just a push - pull on the shift linkage, its a push - twist - pull The new shifter will work like this: (P) = 2nd gear engage (R) = no action (N) = disengage 1st gear if selected (D) = no action, but allows regen brake by shifting gear selector to right (4) = disengage 2nd gear if selected (3) = no action (2) = 1st gear engage I want to use the tiptronic side (right side) of the shifter to enable different levels of dynamic braking. (+) = 50% braking motor torque (-) = 20% braking motor torque Reverse will be selected by a seperate switch most likely. |
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| 2008-06-15 I got the front end off. I should have done this before stripping the engine, I didn't realize how easy the job would be. The engine and tranny are ready to pull. All the fluids have been drained, hoses disconnected; alternator, and power steering pump have been removed; entire exhaust system has been removed. Siphoned the gas tank down to 1/4 tank. |
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| 2008-06-21 I pulled the engine and transmission out as one piece. I used a chain hoist looped over a beam in the garage, making sure to reinforce the beam. This picture shows the two engine mounts, the two transmission mounts, and the 2 half shaft cv joints from the automatic transmission. This pic was taken after two hours of degreasing and pressure washing. The steering rack is tucked up where the heater core hoses go. This is the perfect place for it since the rack and the steering shaft are completely out of the way. |
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| 2008-07-11 I pulled out the entire engine wire harness and brain. There are some signals I will still need like alternator light, water level, throttle position... but those are easy to find on the cars wire harness. The only toughy right now is vehicle speed and engine rpm. I have the sensors but I suspect the computer is needed to make the gauges work. Hopefully I can emulate the signals, and if Im lucky, it is just an analog signal. The cableless throttle could still open and close with the gas pedal, pretty neat. |
My Transmission
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| 2008-06-22 Today I bought a 5 speed manual transmission for $600 bucks, ouch! Hopeuflly I can sell my Automatic tranny and break even. I also found out I need different axles and transmision mounts. The 5 speed manual is much smaller than the automatic, my existing half shafts are not long enough. The manual transmission will probably be left in 2nd gear the entire time. Once the electric motor is above 3500 rpm (max torque), the motor is constant horsepower up to 14000 rpm. In this constant horsepower range, there is only a slight advantage to selecting a higher gear. A higher gear would be quieter, and a lower gear would accelerate faster from a stop. Since I am limited to selecting two gears with the automatic shift linkage, I will wait till it is running to decide which is more useful; 1st and 2nd, or 2nd and 3rd. |
My motor
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| 2008-06-23 Received my motor today. It's a Siemens liquid cooled 42hp (90hp peak) 3 phase motor. Part No: 1PV5133-4WS20 W11 215 - 380 Volt, 282 Amp RMS (400 peak) 6 pole, 3 Phase AC Induction 67 Kw peak (33 Kw continuous) 3500 - 9700 (13,000 Max) RPM Weight: 178 lbs Used on the EV Ford Ranger |
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| The backside. The motor shaft is hollow. The EV Ford Ranger had the left side axle shaft shaft running though this hollow motor shaft. The bearings in the motor have barely any friction, it spins so easy. |
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| This is a picture of the motor with the front cover removed. Bottom right shows the water cooling channel. |
Bearing upgrade
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| This pic shows the tools I used to replace the bearings in the motor. The old open style bearing is shown at the base of the rotor, the new sealed bearing is installed on the motor shaft. Why did I need to replace the bearings? The motor's bearings were lubricated and cooled with an oiling system integral with the planetary gear box on the Ford Ranger. Oil was supplied by flooding the hollow shaft, little holes in the shaft would drip oil into the bearing race. The bearings must be replaced with sealed, lubricated for life bearings, since I do not have an oiling system. The mechanical limit of the sealed bearing is 11,000 RPM. The thermal limit of the sealed bearing is 70 Deg C, this coresponds to a steady state speed of 17,000 RPM. The original planetary gear box with helical gears would put a large thrust load on the bearings. Since I now have a splined shaft, the bearings will have virtually zero thrust and zero radial loading, they should be fine without the need for external lubrication and cooling. Thanks to Russ Sciville from across the pond for noticing these bearings needed to upgraded. |
Motor-to-Tranny Coupling
Motor side of the coupling |
| After weeks of consideration, I determined the best way of interfacing with the motors output gear is with a taper lock. The taper lock is rated to handle 1160lbft of torque. I will likely attach an adapter to the face of the taperlock and bolt it on using the 9 allen bolts.
here is a closeup of the motor shaft |
Transmission side of the coupling |
| 2008-06-22 This is the clutch disc inside the transmission. I plan to drill the 12-hole hole pattern from the rotoflex coupling into the clutch disc. The rigid coupler is easier to build than my rotoflex idea, but since there is no flex, everything needs to be very precise. I'll be sure to leave space in the adapter plate for the rotoflex if I decide to use it later. |
Simple Rigid Coupler |
| 2008-08-04 This design looks like it should be easier to machine. |
Completed coupler - transmission side |
| 2008-10-18 The non-essential parts of the clutch disc were removed. 3 dowel pins locate the cltuch disc to the coupler. |
Completed coupler - motor side |
| 2008-10-18 3 dowel pins locate the taperlock fitting to the coupling. Six bolts clamp the assembly together. |
Completed coupler - mounted |
| 2008-10-18 Coupling clamped onto the motor shaft. The unused bolt holes in the coupler are used as jacking threads when removing the taperlock fitting. You can see an imprint in the taperlock fitting from the gear teeth. |
Bell housing adapter
Taking measurements |
| The transmission and motor were mounted in a CNC. All dowel pins, shaft centerlines, and bolt holes were located using a dial indicator mounted to the spindle head. |
Bell housing adapter - Motor side |
| The adapter plate was made from 3/4" aluminum plate. 2 dowel pins, and a centering ring locate the plate to the centerline of the motor shaft. The plate is bolted to the motor using 14 counter bored allen bolts. |
Bell housing adapter - Transmission side |
| Three dowel pins were machined into the bell housing adapter and match the existing dowel pins on the transmisison. 7 bolts will attach the plate to the transmission. |
Bell housing adapter - Just Married |
| Another completed milestone! |
Motor mount   |
| Motor and tranny mounts are done! |
Motor Controller (VFD)
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| Eurotherm (SSD) drives 2 horsepower 690 variable frequency drive VFD will not be run from 230vac, I will connect a 300vdc battery pack to the internal dc bus. Two of these drives will be used, one for the traction motor, and one for a motor running accessories like power steering and air conditioning |
Tischer's Motor Controller Upgrade
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I will disconnect the VFD's 7 Amp internal IGBT packs (high power switching transitors) and connect them to my custom 600 Amp external IGBT pack. Six of these IGBT's will be required, one for the top half of a sine wave, one for the bottom half, and three pairs will be used to make three phase power for the electric motor.
The original ford motor controller looks like it uses similar IGBTs. One side shows some big capacitors and the IGBT packs. The other side a small firing circuit which converts the signal from the hall effect sensors into PWM signals for the IGBTs. ---UPDATE--- I'm not using these modules anymore, see below. |
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| A bridge circuit to convert AC to DC. This will allow me to test my car by using an AC outlet instead of a battery pack. |
 (from wikipedia) |
| According to this drawing, I have everything I need to build my external IGBT pack! This is going to be so easy... Yeah... How hard could it be... |
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2008-07-06 Started modifying my VFD (motor controller). I removed one of the circuit boards from my drive, and it still runs fine. ---UPDATE--- Motor runs about 4x normal current, Im using this board again. The only important thing on the removed board are two curent sensing devices (two black boxes). These current sensors will need to be upgraded and I will have to trick the drive into thinking it is only outputting 10 Amps when its really outputting 200. Hopefully these black boxes are just a shunt. Since the drive still functions, maybe these current sensors are only used when performing an auto-tune in a vector mode? Here's a video of my midnight smoke test. |
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2008-07-08 I wired up and tested my precharge circuit. I also got my IGBT to turn on a lamp. Lamp current starts to flow though the IGBT at 6.5 volts, and stops flowing at about 6 volts. In between 6 and 6.5 the IGBT puts out a varying current, this is bad because it means half the power is going to my lamp, the other half of the power is heating up the IGBT. I need to make sure my circuit is either above 6.5 or below 6, I want the IGBT either fully on, or fully off. This is the circuit I used. |
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2008-07-19 Shown above is the IGBT pack I removed from the VFD (data sheet). The IGBT packs I bought are only IGBTs, they dont' have the supporting circuits. (data sheet) The supporting circuits are needed. See the waveforms below. |
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2008-07-19 That's what the signal looks like going to the input of the original IGBT. The scope is connected between Vvpc and VP. This waveform replicates the top half of a sine wave. The signal is about 14 Volts peak to peak. Here is another view showing multiple cycles. When I stop the drive, the output going to the IGBT goes to constant 14v, instead of 0v. This leaves the IGBT 100% on, instead of off, this seems backwards. |
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2008-07-19 Here is the same waveform as above, but zoomed in. I also have the original IGBT disconnected. The signal is now 18.4 Volts peak to peak because there is no load. The frequency is about 3kHz. |
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2008-07-19 Now when I connect my external IGBT, the signal looks like it is overloaded. The signal is now only 5.4 Volts peak to peak. |
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2008-07-21 Bought one of these " Smart Power Modules ". This more closely represents the IGBT device I pulled out of the VFD. It has onboad signal conditioning which was lacking in the IGBT's that I originally bought. This should solve the problem of my square wave turning into a triangle wave. This Power Module also eliminates alot of wiring since the six IGBTs are prewired internally. I only have to connect the battery and the motor, and I only have to mount one device to a heat sink. |
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2008-08-17 This is my working prototype. I have six 400V 3,900uF caps providing a low inductance bus to the IGBT power module. The capacitor wiring is what caused my previous power module to blow up, the copper bus bars and short cable length from the capacitors to the power module should solve my problem. |
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The back side of my prototype.
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I wire wraped the pins on the IGBT power module because the pitch and pin diameter didn't work well with standard connectors. A loose connection here would destroy the power module.
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2008-08-20 This is what the IGBT firing waveform looks like with my new power module. The corners aren't as sharp as they used to be with the old power module but I think it will work. The old signal was 14v pk-pk. Looking at the lowest peak and the highest valley, (curser a and b) the voltage is 12.3 pk-pk. |
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A picture of my watercooled heat sink.
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Aux Motor
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| Dayton Washdown rated 2 Hp 3 phase motor This is the drive which will run my power steering, alternator and AC compressor. I will use a second 2 Hp Eurotherm VFD to run this motor. Since the motor is rated 3450 RPM I may use a smaller pulley, or run slower speed with the VFD. |
Battery Decision Matrix
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Specs |
to Empty |
| 13,000mAh "F" NiMH 40A Discharge Rate 60A for "short time" Limited to 500 cycles |
4 in parallel per group * 250 groups | 1000 cells | $11,1600 | 525 Lbs | 300v, 52Ah, 240A |
43 Miles |
| 4,200mAh "Sub C" NiMH 30A Discharge Rate Limited to 500 cycles |
8 in parallel per group * 250 groups | 2000 cells | $7,196 | 299 Lbs | 300v, 33.6Ah, 240A |
28 Miles |
| 1,100mAh "2/3A" NiMH 12A Discharge Rate Limited to 500 cycles |
30 in parallel per group * 250 groups | 7500 cells | $5,987 | 337 Lbs | 300v, 33Ah, 360A |
28 Miles |
| 2,600mAh "AA" NiMH 2.6A Discharge Rate |
92 in parallel per group * 250 groups | 23000 cells | $25,399 | 1419 Lbs | 300v, 239Ah, 240A |
201 Miles |
| 10,000mAh "M" Li-Fe-PO4 20A Discharge Rate 50A Discharge for 30s |
5 in parallel per group * 100 groups | 500 cells | $18,730 | 429 Lbs | 320v, 50Ah, 250A |
45 Miles | 4,500mAh "F" Li-Fe-PO4 90A Discharge Rate 110A for 30s |
7 in parallel per group * 100 groups | 700 cells | $18,347 | 271 Lbs | 320v, 31.5Ah, 700A |
28 Miles | 2,600mAh "D" Li-Fe-PO4 60A Discharge Rate 75A for 30s |
12 in parallel per group * 100 groups | 1200 cells | $19,752 | 285 Lbs | 320v, 31.2Ah, 720A |
28 Miles |
| 10,000mAh Flat, Li-Fe-PO4 20A Discharge Rate 40A for 18s |
6 in parallel per group * 100 groups | 600 cells | $26,976 | 341 Lbs | 320v, 60Ah, 240A |
50 Miles |
| Optima Blue AGM 55Ah @ 20 hr |
25 battteries | 25 battteries | $4,725 | 1095 Lbs | 312v, 30Ah (@72A discharge) | 27.5 Miles |
| 75Ah Optima Blue AGM 75Ah @ 20 hr |
25 battteries | 25 battteries | $5,725 | 1495 Lbs | 312v, 48Ah (@72A discharge) | 40 Miles |
| 12Ah 6v Sealed Lead Acid Note: With 1c (12Amp) load, capacity drops to 7Ah due to Peukert effect |
6/group * 52 groups | 312 batteries | $5,988 | 1363 Lbs | 312v, 42Ah (@ 72A discharge) | 35 Miles |
| Trojan T-105 (Flooded Golf cart 6V) 225Ah @ 20hr 143Ah @ 2hr |
50 Batteries | 50 Batteries | $6,400 | 3100 Lbs | 300v, <143Ah | 120-40 Miles |
I decided to use the Optima 55Ah Blue AGM batteries.
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These four batteries fit where the gas tank used to be. I have ribs under the battery box which snugly fit my floor jack to help safely lift the pack.
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Cost
Parts |
Description |
Cost |
| Chassis | 2001 VW Passat, Automatic, fried engine | $1800 (craigslist) |
| Transmission | EHV code. 5 speed manual | $640 VW Recycler |
| Exchange Axles | Longer axles for the smaller Manual Transmission | Not purchased yet est $200 |
| Battery | 25 Optima Blue Batteries | Not purchased yet est. $5,0000 |
| Electric Traction Motor | Siemens - Ford Watercooled 3 phase 90 hp | $975 + $300 shipping (ebay) |
| Upgraded Traction motor bearings | SKF 6209 2Z/C3 | $100 (MotionIndustries.com) |
| Motor Controller | Eurotherm Drives 2 hp 230v 3 phase for Traction motor |
$36 + $15 shipping (ebay) |
| Controller upgrade | (7) IGBT packs | $279 (ebay) (unused) |
| Electric Accessories Motor | Dayton Washdown rated 2hp 230v | $28 + $18 shipping (ebay) |
| Motor Controller | Eurotherm Drives 2 hp 230v 3 Phase for Accessory motor |
$68 + $15 shipping (ebay) |
| 12v Vacuum pump | Used to make brake booster work | $140 (ebay) |
| 60A bridge, (2) 2700uF 450v Caps | Used to make 300vdc powersupply | $40 (ebay) |
| Fuses, Fuse holders, (2) 12v 3ph contactors | Used for 300vdc precharge & safety circuit. | $40 (ebay) |
| Smart Power module IGBT 6 pack | Replaces IGBT pack removed from drive | $440 (Powerex) |
| Tyco /Kilovac Contactor | 12v coil, contacts rated 500A 1200V | $95 (ebay) |
| 12v Supply | Replaces alternator (or I may use the OEM Alternator) | $100 |
| Taperlock | McMaster Carr 2328K18 | 51.34 * 2 |
| Machine shop services | $800 | |
| Misc angle iron | $200 |
Calculations
 Download my EV Calculator spreadsheet |
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From my calculations I should beable to achieve 0-50mph in 13 seconds, the EV Ford Ranger is spec'd at 11.6. My calculations assume I'm not exceeding 100% rated torque, I plan on pulling 150% for atleast a few seconds =) The Ford Ranger EV effeciency is rated 356Wh/mile @ 60mph, 237Wh/mile @45mph. With the small Optima pack above, I should get a range of about 35 miles. Interestingly the Ford ranger with a similar battery pack advertises a range of 65 miles. Their numbers don't add up, 337wh/mile * 65 miles = 22kwh, but their battery is only 19kwh which you'd be lucky to get 15kwh out of. |
