How big the motor need?

[kubing]

inverter shown on picture are for testing purpose only and soon will be use to power up my diy lathe.

since i built my own controller to communicate with x-sim via usb. so i need to test every single things before i burn USD400 inverter .from datasheet my inverter is input single phase 240v and output 3phase 240v. 150% over current mean i need at least 0.55kw to 1kw inverter for 0.37kw motor? can you explain that

[vicpopo]

Hi Kubing,
With the SEW inverter MovitracB you setup this parameter overload current at 150% directly when you start parametring it.
If you can validated this value that means that is possible to reach this current value without burning anything.
That the reason why often with an inverter configuration you have a thermic monitoring into the stator.
Normally when you use a motor from 0.37 kW you choose an inverter according with the same power value 0,37 kW(it accepts 150% overload current and I don't have all the values in head but for a 0,25 kW the regular load current is 5 A and with 150% we are speaking about max 7A)
The inverter from Sew(single phase to 3 phases) is done for a range of power from 0,25 kW to 2,2kW (0,25 -0,37-0,55-0,75-1,1-1,5-2,2).
Best regards

[kubing]

Normally when you use a motor from 0.37 kW you choose an inverter according with the same power value 0,37 kW(it accepts 150% overload current and I don't have all the values in head but for a 0,25 kW the regular load current is 5 A and with 150% we are speaking about max 7A)

I think you invertor is also monophase so you could have the same problem we have. Make sure to allow an overcurrent of 150% and buy motors that have a thermal safety

here is my inverter basic data spec. seems like they can't power up 0.37kw motor. the max current only at 2.3A for continuous run. as you know this may vary according motor brand.

*Overload capability: 200% for 3 s and then 150% for 60 s (related to nominal current)

[Mertensbart20]

Hello kubing,

Your invertor is fine. The nominal current of a 0,37kW motor is 2.15A. The problem you can face is that if you are not going to apply forced cooling you torque will fall in the lower frequencies (see the first page of characteristics I included). Also above 50Hz the torque will drop.

If you would use 3-phase invertors you can look at the characteristic on the second page and thus the torque will not drop even at 87Hz. The reason is the U/f rules of invertors but that is rather technical.

In conclusion, if you use forced cooling and don't go above 50Hz your invertors are fine. I assume ofcourse that you motors are strong enough. What type of motors are you going to use?

[vicpopo]

Hi Bart,
I don't know if you can choose different kind way for driving the motor with the inverter.
Don't ask me to explain you what is the vector flow control but as I know with my inverter I don't use the rule U/f for driving the motor (torque limitation you describe).
I use the VFC mode which is recommended for dynamic applications.I write what the starting guide says:
-high torque
-continuous duty at low frequencies
-Accurate slip compensation
-More dynamic behavior
There are 4 kinds of VFC driving -VFC ,VFC DC braking,VFC flying start function, VFC hoist.
I use ( not yet tested in full motion) the VFC mode.
I use too a breaking resistance with the inverter (recommended with this application)
Best Regards

[Mertensbart20]

Hi vipopo,

You are right about the vector control invertors. Those are the most suited for that kind of application and the most expensive . But the question is also how far you want to go. We want to create an arcadestyle racesimulator, not a realistic one. So scalar invertors will do the job for us. Last year we build one by the design of Thanos with wipermotors and this works also pretty good (considering the motors and the control loop):

https://www.youtube.com/watch?v=q6HtIFWxAf4

And you can always change the the invertors at a later point in time.

Bart

[vicpopo]

Hi Bart,
You're right and I saw your project.My target isn't to sell inverters!
If it's what someone could make as interpretation reading this post it's not my goal!
My target is just to share what I learned using this material and I know (I said that several times) that this material is very expensive.
The Xsimer beginner doesn't want to pay so much and with DC motors ,Thanos AMC board you can reach very good motion ,I agree with you.
Personaly I've got a 2DOF simulator with k8055 and sabertooth with bigworm motors.
I'm impatient changing this configuration with amc 1.6 and dual h-bridge designed by Speedy (I don't want buy Pololu driver and it's funny doing all by myself)
The ac motors is the next step probably with 3 DOF or more and I want to keep dc motors for a motion seat project !
Best Regards

[Mertensbart20]

For the motorcontroller you could also take a look at this site:

http://www.dimensionengineering.com/

The sabertooth2x25 could be interesting. With a special USB-connection you can change te responsivenes of the controller to your needs. If the Sabretooth is not strong enough you can go for the sabertooths2x60. We used the sabertooth2x25 in our first project and I was very satisfied with the results.

Bart

[motiondave]

JRKS run 14v at 30 amps continuous, just add some decent size motors like these http://www.motiondynamics.com.au/worm-d ... orque.html

[kubing]

In conclusion, if you use forced cooling and don't go above 50Hz your invertors are fine. I assume ofcourse that you motors are strong enough. What type of motors are you going to use?

Sew eurodrive on my short list * but still looking for cheapo solution if any. I'm okay with DC but its not an option for *.

My target is just to share what I learned using this material and I know (I said that several times) that this material is very expensive.
The Xsimer beginner doesn't want to pay so much and with DC motors ,Thanos AMC board you can reach very good motion ,I agree with you.
Personaly I've got a 2DOF simulator with k8055 and sabertooth with bigworm motors.

just like you. I wish to share the knowledge and lesson (especially the bad one so you wont repeat my mistake) with community. the price for new vfd is very expensive. But here in Malaysia with so many Japanese and Singaporean factory around. i can get the USED inverter with the price of pololu dual motor driver . But i still need to buy super expensive gearmotor.

JRKS run 14v at 30 amps continuous, just add some decent size motors like these http://www.motiondynamics.com.au/worm-d ... orque.html

JRK is great. my friend use this controller for sumo robot. small and powerfull as far as i * But i have build my own controller with usb before and match it with pololu dual motor driver. serve me about 2 and half years i think.