Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

[thingstodo]

Originally Posted by MPaulHolmes

The soft start is a good idea. Right now I was just ramping up voltage at startup, but I didn't ramp up frequency too.

Does that work to limit the current on startup? With less voltage applied, I would expect that the startup current would be lower than 10 times rated amps ... but my experience is with 3 phase motors. I'm a bit iffy on single phase motors

My single phase motors all have capacitor start. Does yours?

[Stubby79]

Is it really that difficult to soft start a single-phase motor?

I suppose it's having a full load already present that makes it a headache.

I have a good sized motor to test it on...I'll have to muck around with it. Just what I need, another project!

Thyristor control not work? You could literally dial-up the power...

oh, wait, this is derailing the topic. Back to whatever you guys were discussing.

[thingstodo]

Originally Posted by Stubby79

Is it really that difficult to soft start a single-phase motor?

I'm not sure! I guess that's where the discussion starts - when no one actually knows ....

I suppose it's having a full load already present that makes it a headache.

Plus, in my case, trying to use a lower voltage, like 48V, to run what should be fed from a buss that's about 150V .... wait - that would be for single phase 120V not 220V. Paul - what voltage are you running your Buss at to get 220V?

Thyristor control not work? You could literally dial-up the power...

I think that's what my 3 phase soft starts do at work. That's a variation on what Paul does, reducing the voltage on start but not changing the frequency. We drop from about 10X rated current on a loaded start to around 3X rated current on a loaded start with the thyristor-based soft starts. With an AC controller, you should be able to stay under rated current the whole time and not heat the crap out of your motor .. in theory.

[oil pan 4]

It's very difficult to start a single phase capacitor start motor with a load attached.
The start circuit doesn't kick off till the motor is at least 75% to as much as 85% of running speed.

It's bad enough that I am switching one air compressor over to an ABB drive and 3 phase motor.
I have the motor and drive l, just need to get it on the compressor.

[Stubby79]

Originally Posted by oil pan 4

It's very difficult to start a single phase capacitor start motor with a load attached.
The start circuit doesn't kick off till the motor is at least 75% to as much as 85% of running speed.

It's bad enough that I am switching one air compressor over to an ABB drive and 3 phase motor.
I have the motor and drive l, just need to get it on the compressor.

Put a CVT or at least a centrifugal clutch on it? Just gotta make sure it doesn't slip under full load...at least the CVT would just "gear down" instead.

[MPaulHolmes]

thingstodo, for the pump, you have 3 phases to work with, so you could use one of the 3 for a boost converter, and then the other 2 for generating the 120v or 240vAC. I can do up the code when you are ready to do that.

[MPaulHolmes]

thingstodo, for the pump, you have 3 phases to work with, so you could use one of the 3 for a boost converter, and then the other 2 for generating the 120v or 240vAC. I can do up the code when you are ready to do that.

[oil pan 4]

Originally Posted by Stubby79

Put a CVT or at least a centrifugal clutch on it? Just gotta make sure it doesn't slip under full load...at least the CVT would just "gear down" instead.

I already did that and it works. I didn't use a CVT because they need their own varrible drive and driven pulleys and the problem with the small CVT clutches is they appear to be for 2 pole motor speeds and higher, I am now using 4 pole motors. I would use 6 pole motors but I can't really find any that fit my application.
But I did use a modified go cart clutch and a Dayton electromagnetic clutch with very good results.

Eliminating start up inrush current - EcoRenovator

[thingstodo]

Originally Posted by MPaulHolmes

thingstodo, for the pump, you have 3 phases to work with, so you could use one of the 3 for a boost converter, and then the other 2 for generating the 120v or 240vAC. I can do up the code when you are ready to do that.

I have a large (300 A, 800V rated) inductor that I can use for the boost ... it's actually bigger than the controller and *MUCH* heavier but I have it and it should work fine.

I should start on this project ... this weekend ... since I need the sump pump to run for our upcoming spring season

But I'll be loading the 3 phase code first and going through some testing to make sure all is wired correctly before I start with the experimentation.

[MPaulHolmes]

I'm heading up to washington/oregon for work until the 3rd, so I won't be horribly useful until then, but I might be able to do some stuff.

Oh! We just got a wrecked Nissan Leaf that was only $2900 at an auction (hurray for the line of credit haha).

It turns out that basically it was just the side panel that was damaged, and a cheap blinker. So, they totalled it out, and it is costing us around $200 to totally repair it to almost like new. Crazy insurance people!

I would like to stick the controller in there, but it's a veritable nanny state. I don't want to brick the car with error codes. Even the steering wheel is electronic. Does anybody know if I could just take the stock controller out, and stick mine in, and then disable some stuff, and drive around, or will that mess up other systems like the steering?