UK Insight EV Conversion

[retepsnikrep]

Thanks for feebback.

I have to discuss all the intricate engineering with my engineering contact with all the bits on the bench and some detailed measurements. I have no problem paying to get aluminium parts recess machined to form a suitable bearing support. If we say the pulley end plate we have a pattern for that at the other end of the engine It could be machined out a 2-3" block of aluminium and all the internal mass machined out to give a lightweight but strong. support. Ditto the intermotor bearing support. The total length of the 5 motors and bearing supports must roughly equal the present length of the engine with single ima attached. As there won't be a pully on the end that gives us a couple more inches at the water pump end.

I'm dumping the aircon I never use it. To save weight and avoid the complexity.

The box on top will have 5 stripped out MDM's in place.

They will consist of the Voltage converter modules (igbt driver), IGBT's and filter caps/for each motor. I may use civic filter caps as they are smaller and higher rated.

Only the master motor (the one on the clutch end as now) will have commutation sensors and phase sensor. All the stacked motor internals will be perfectly alligned at assembly.

I'll only be using one MCM it will only recieve feedback from the master motor but the drive signals will be fed to all the Voltage converter modules.

I'm going to start off by getting one motor working properly on the bench then in the car and do some testing on performance with one ima motor others unconnected. Then i will add them in stages. I may use an Insight nimh pack for limited testing on the bench. I may make up a larger nimh pack using the 4 packs worth of nimh cells I have kicking about for road testing. Once it's all sorted then i might be able to afford the lithium cells!!

I think around 120-125hp peak may be achievable with a ~220v pack and stacked A123 cells.
250ft/lb Torque might be an issue for gearbox and clutch!!

If you look at the Honda CRZ race car specs they have upped the voltage from 108 to 173 to go from 13-25hp which is basically what i have been doing

Peter

[retepsnikrep]

Had a long chat with my engineer today and left him the short engine block, two ima motors and clutch assembly. He's now going to do some measuring, thinking and costing and then get back to me in a few weeks! Good job it's a long term project. The aluminium bearing support plates should not be an issue, as we have discussed though getting the rotor alignment and mounting sorted is more tricky. He seemed pretty optimistic and enthusiastic about the whole project so fingers crossed.

[Hugh-Falls]

Originally Posted by retepsnikrep

.........If you look at the Honda CRZ race car specs they have upped the voltage from 108 to 173 to go from 13-25hp which is basically what i have been doing Peter

Would the additional horsepower gain be desirable if a 100.6 volt stator (GenII Insight) were installed in your PHEV Insight and would the present existing electronics be able to handle the additional current? Casual measurements done recently here comparing the GenI and GenII stators suggest interchangeability is possible. The rotors and sensors, of course, are different. Another question: Can the GenII stator windings handle the additional current?

This interchangeability (if possible) also suggests that a shorter lighter stack of comparable horsepower could be built using fewer IMA motors.

[retepsnikrep]

Interesting Idea Hugh. Unless you are racing the current issue is probably a non issue for road use as by the time the stator burns out you would be in jail for speeding anyway.

A direct swap of the stators would be interesting. The present electronics will only allow a set current to flow unless you hack it so a simple stator swap would not release more power (beyond the effecieny improvements between gen1 and gen 2 motors) unless you could up the current/voltage as well.

Using gen 2 or crz stators could be for MK2

I have my work cut out with the gen1 stuff and some more hacking. My machine shop guy is flat out at the minute so no progress there until winter probably

[retepsnikrep]

Well I took my motors and old engine block to Newcastle university Engineering dept the other day and had good chat with a couple of the Academics and some students there about the problems and ideas for assembling them into a block of 5 stacked.

I had made contact after helping some of the students with a BMS for their EV entry in an upcomming international competion. I left my motors and drawings and they are going to take some measurements and a few notes.

Whilst there though we looked at their EV project car a lightweight open single seater. The motor and batteries they are supposed to use for the competion are being donated by a UK EV firm who don't seem that interested or ammenable but the lead academic slipped one of my IMA motors into the vehicle and we discussed a direct drive setup with two per driveshaft and two independenty controlled IMA drive units. The academic had a serious glint in his eye when he slotted an IMA motor into the car!! LOL If fitted like a proverbial glove so I can see I might have to lend them to the students for a year.

I have stated if they can initially assemble two IMA motors into a single unit with one commutation sensor disc fitted that can be run on the bench then i can develop/modify the IMA drive system at my workshop. So we might kill two birds with one stone. I get to develop the drive electronics for my own project and lend it to them and they assemble the motors.

In escence they would end up with two or more motors per side driving the associated driveshaft directly. As the motors develops 98nm at 10kw that could equate to over 350NM per wheel when driven at 18-20kw. I also mentioned the IMA start mode which spins the motors upto 1000rpm very quickly and that perhaps it could be a sort of launch/start mode

They are going to do a feasabilty study on the idea and some clever calculations on torque acceleration etc etc etc I'm happy to assist as much as I can. All very interesting.

[nasphere]

That sounds like tons of fun! I think maybe after a year or so, we may be able to get specs on how the MDM interface works, and reprogramming the MCM's processor to accept serial commands might be possible then. Most inverters that i've seen have both RPM and torque inputs. Most of the time you set RPM to max, and attach the torque to the gas pedal.

Keep up the good work on this! I know it's slow, but it's important!

[retepsnikrep]

Now finally some progress and have had some motors on the axis measuring gizmo and got some basic drawings and some parts are being made next week or so. Starting off with bolting two motors together with one sensor plate for bench testing setup. See if one MCM can drive more than one lot of power electronics or one IGBT can drive two motors with stators in parallel.

[nasphere]

Originally Posted by retepsnikrep

or one IGBT can drive two motors with stators in parallel.

I have to interject, my experience with paralleling PM brushless motors killed a controller. I would suggest two IGBT (MDM) units for two motors so the slight difference in inductance and flux between the two motors isn't relayed to the single IGBT unit.

[retepsnikrep]

Well like anything delays again.

Found with a remeasuring of two motors clamped together with dowels etc so cases perfectly aligned that stators were out of line by over 2mm. I suspect if i just bolted these together that would cause an imbalance and also be critically close to fouling the rotor if they were all perfectly aligned on a shaft.

Now measuring a further two motors to see if this misalignment is common, or i have a rogue motor. One certainly has come out of a crash damaged car which had sustained a severe frontal impact perhaps distorting or shifting the stator. It's heavy part to suddenly stop moving in a frontal impact.

[Hugh-Falls]

Peter: To start with, you need to mark each stator and rotor as a discreet pair/assembly before you separate them. There seem to be variations amongst rotors and they may not be interchangeable in other stators.

You may want to try measuring the alignment of the stators using the 13mm mounting holes as locators rather than the dowels. The two engine side OEM mounting dowels are the only ones used in my motor and only to locate the two adapter plates. Adjacent motor sections are located to each other and to the adapter plates using 5/8 od x .527 id stainless steel tubular dowels at two oposite (L & R) mounting holes which are reamed to a depth of about 3/8 inch on both mounting surfaces. The dowels are easily made by slicing them 5/8 long from the tubing and manually beveling the ends at a grinding wheel. The 1/2"-20 threaded rods slip through these tubular dowels.

Peter, I'm glad you discovered this problem and I will now go back and check out the alignment of the stators again to make sure they line up. If they do not line up, I will have to re-align the stators within the cases and repin them.