[Akshay677]

Hello I am working on my post graduation project related to conversion of Toyota Yaris(sedan)

What type of AC motor should I use in order to attain a maximum speed of 120kmph?
What type of battery pack should I use in order to obtain a range of 120kms or more?

Please help me with relevant calculations to support your answer

 

[arber333]

Hello I am working on my post graduation project related to conversion of Toyota Yaris(sedan)

What type of AC motor should I use in order to attain a maximum speed of 120kmph?
What type of battery pack should I use in order to obtain a range of 120kms or more?

Please help me with relevant calculations to support your answer

I have a 1200kg Mazda which goes 150km/h on a 30kW air cooled motor even 160km/h max is not a problem. BUT at that speed motor sinks cca 70kW. I am not sure how much it gives in Pm exactly, but wattmeter says 70kW.

What are you postgrad off? You can easily calculate needed power for level drive at certain speed. All the formulas are known. I bet there is a Cd for Yaris online as well as Ctr for tyres.
You can make a spreadsheet that calculates your power and range at certain speeds. I made one and i even put in GPS points at 1s intervals to get energy required for trip and calculate range. I could not make regen calculation work though . I just ignored it then.
What i did in the end was calculate all resistance for level drive and multiplied by 1.2 due to transmission and bearing losses. When i wanted power on a hill i just took the largest slope i will most likely be driving on and calculated hill force and added that to get P required.
The precision of calculation was scary!

It seems to manage largest highway hill my car requires 40kW of constant power. Thermal management of air cooled ACIM is well within that at least for 10 minutes.

I wish for a water cooled motor though. That would mean longer time under high power for those extended trips to the sea .

I imagine you would need 20kWh to reach 120km. Maybe Leaf pack? Since it is a light car you could get away with Volt pack for 100km range!
I have seen Smart EV top 120km with 16kWh but at speeds under 80km/h not more!

A

 

[MattsAwesomeStuff]

I have seen these types of questions in other forums from this place in the world...

In the end it turns out we were doing someone's homework.

I'm suspicious.

 

[arber333]

I have seen these types of questions in other forums from this place in the world...

In the end it turns out we were doing someone's homework.

I'm suspicious.

That is why i am willing to offer guidance not actual formulas. Lets see if they follow up.

 

[Akshay677]

These are the calculations I have done on my side.

I have assumed 10% gradient.
Mass of the vehicle is considered to be 1916 kg ( I have assumed the battery pack may weigh 30% of curb weight)
overall gear ratio=7.8066 (assuming car will run on 2nd gear)
wheel radius= 14"

Rolling resistance force= 187.026 N
Aero Drag= 517.477 N
Gradient Resistance= 1870.40 N

from above values Power= 84 kW
torque= 140 Nm

are these values correct? Please suggest corrections if any

 

[Akshay677]

Sir I will be glad if you guide me in this work.

 

[arber333]

Sir I will be glad if you guide me in this work.

It is late and i will offer quick guide. More tomorrow...

Motor industrial size 132M provides some 20kW nominal with inverter.
https://www.ebay.co.uk/itm/7-543TEC...390537?hash=item4d5586f849:g:lbYAAOSwOgdYvucB

For HV I would recommend Mes Dea motor with gearbox if you can get one, they are hard to get. It is water cooled and high rev. motor. http://www.metricmind.com/data/ac_induction_motors_carraro.pdf
They converted similar car than yours...
http://www.greencarcongress.com/2011/04/lupoel-20110409.html

And i know this motor is appreciated in Slovenia for smaller conversions up to 1000kg and 120Vdc. They couple them with Curtis 1238 controller. I know for a fact this motor is used in Renault Twizy.
https://eauto.si/metron-shop/product/mahle-letrika-conversion-kit/
http://www.evalbum.com/4728

Inverter i recommend you make one from kit
http://johanneshuebner.com/quickcms/index.html?en_inverter-kit,10.html

BUT i can even make life less complicated and offer you a kit from the same inverter design to be used with Opel Ampera/GM Volt inverter. That would shave some 500€ off inverter price and loads of time from power stage design and building. And i can offer even AC compressor drive in the same package. I am currently testing my design.

What is your preference LV or HV system and what motor can you get?

 

[Akshay677]

From above obtained values I am thinking of using HPEVS AC x 35 144 volts 500 amps electric motor. It offers a peak power of around 123 kw @ 5000 rpm

is it a good choice?

 

[arber333]

From above obtained values I am thinking of using HPEVS AC x 35 144 volts 500 amps electric motor. It offers a peak power of around 123 kw @ 5000 rpm

is it a good choice?

Yes that option is a good choice for your car. You should know your car will loose weight too. Engine, exhaust, fuel tank, spare tyre etc... weigh some 200kg. Also batteries at 20kWh energy also weigh about 200kg. So your car could come maybe 50kg heavier than stock if you are carefull.

 

[Akshay677]

Sir I have done certain calculations considering ev should travel 150 km and I have found out battery capacity to be 35 kWh.
Is this correct?

how can I check whether my calculations are correct?

 

[MattsAwesomeStuff]

how can I check whether my calculations are correct?

Why don't you show us the calculations you did, and then explain why you did each step, and then we can tell you whether that makes sense.

 

[arber333]

Sir I have done certain calculations considering ev should travel 150 km and I have found out battery capacity to be 35 kWh.
Is this correct?

how can I check whether my calculations are correct?

You are not physics student are you? That is oversimplifying things.
Make a diary of your project. Put in the formulas, check the route you will drive on and then add energy requirement as you drive along the road. You will see exactly at wat speed you can drive and how much a hill your motor fights. You will derive your energy requirements from there.
When you research this you will have more clear idea what is needed.
Othervise it is just doing the work because you must and that is not fun at all.

A

 

[henrykeultjes]

Use modular Switched Reluctance details keultjeshatgmall