VFD single phase input three phase output

[Al_The_Man]

Can a standard 3ph ac motor + encoder be used like a vector duty motor in combination with a sensored vector drive?

I have purchased Mitsubishi VFD's with the encoder option and used a standard 4pole 3ph motor with success.
The reason I used Mitsubishi at that time, they had an Ebay account and they would dump last years models of CNC equipment, I would pick up a pallet of 10 VFD's for $1000.00.
Unfortunately they don't anymore.
Max.

[mactec54]

For my application I want to run the final output at around 60 to 100rpm, basically its an unwinder application so I want to maintain constant velocity of the process. But the rpm of the motor would need to change to maintain the process velocity of certain m/s. As the spool starts getting empty the motor would need to speed up to keep the process velocity.

If this is what you want to do then you need a Servo Motor and Drive, Not a VFD driven AC motor

[mactec54]

So If I get you right is an inverter duty motor same as vector duty motor?

Yes, the only difference is one has an Encoder the other does not

Does vector duty motor have better insulation and better cooling and an encoder attached. I mean apart from these 3 differences is there anything more to a vector duty motor ?

Yes they have /use different heaver wire in the windings better insulation better cooling and an Encoder usually 1024 PPR, so over all a very different built motor

Can a standard 3ph ac motor + encoder be used like a vector duty motor in combination with a sensored vector drive?

No it could never have the performance of a Vector or Inverter Duty motor especially at the lower speeds, you can add an Encoder, to a regular AC motor, and use a vector drive, but would be a light weight in comparison to a real Vector Duty or Inverter Duty motor, so if you need good torque at low RPM it's not going to last very long

[Al_The_Man]

r?
Can a standard 3ph ac motor + encoder be used like a vector duty motor in combination with a sensored vector drive?

Incidentally the Mitsubishi drives with the encoder and standard 3ph motors were implemented 15yrs ago and in daily production today.
As I posted in a previous post, I have watched in person a VFD demo of a gantry crane lift, holding a load stationary with a standard motor!

Closed-loop vector control uses a vector algorithm to determine output voltage, much like the open-loop control.
The key difference is that closed-loop vector uses an encoder. Encoder feedback, paired with the vector control, means 200% of the motor’s rated torque is available at 0 rpm.
This is a selling point for apps required to hold a load without moving, such as elevators, cranes, and hoists.

Encoder feedback allows for speed responses over 50 Hz and speed control ranges of 1:1500, the highest of all the control methods.
Closed-loop control can also run a motor in torque-control mode. Torque control lets the VFD control motor torque rather than motor speed.
This is needed in any application where torque is more important than speed. Winders, rewinders, capping, and web applications are good examples of where torque control is used.
Al.

[Jim Dawson]

For my application I want to run the final output at around 60 to 100rpm, basically its an unwinder application so I want to maintain constant velocity of the process. But the rpm of the motor would need to change to maintain the process velocity of certain m/s. As the spool starts getting empty the motor would need to speed up to keep the process velocity.

Since accurate rotational position is not needed, then I would use a 15:1 gearbox, an inverter duty motor, and a sensorless vector VFD. That would keep the motor in the 900 to 1500 RPM range, or use a 20:1 gearbox and run the motor 1200 to 2000 RPM. The RPM control will be very good, and the cost would be less than going with a full on vector motor. The speed control method would be the same no matter what system you finally decide on.

[ZeroBacklash]

Thanks everyone for your highly valued suggestions, I really appreciate it!!

Since accurate rotational position is not needed, then I would use a 15:1 gearbox, an inverter duty motor, and a sensorless vector VFD. That would keep the motor in the 900 to 1500 RPM range, or use a 20:1 gearbox and run the motor 1200 to 2000 RPM. The RPM control will be very good, and the cost would be less than going with a full on vector motor. The speed control method would be the same no matter what system you finally decide on.

Thanks for the feedback Jim, would a motion controller do the job? I mean I would need to measure the diameter of the spool with a sensor and also a sensor to measure the process velocity in m/s to keep the m/s constant. So if i use a motion controller I would need to write gcode right?. However I guess the sensor outputs would need to be compatible to be read by a motion controller. So around 4 - 20ma or 0-10V. I am thinking should I use a regular Arduino or Motion Controller or a plc?
I have a motion controller from CNCDrive, the UC400ETH. Basically I'm trying to ask what would be the best control for this job?

[ZeroBacklash]

If this is what you want to do then you need a Servo Motor and Drive, Not a VFD driven AC motor

I need to understand this why is a VFD not well suited for this application?

[Jim Dawson]

Thanks for the feedback Jim, would a motion controller do the job? I mean I would need to measure the diameter of the spool with a sensor and also a sensor to measure the process velocity in m/s to keep the m/s constant. So if i use a motion controller I would need to write gcode right?. However I guess the sensor outputs would need to be compatible to be read by a motion controller. So around 4 - 20ma or 0-10V. I am thinking should I use a regular Arduino or Motion Controller or a plc?
I have a motion controller from CNCDrive, the UC400ETH. Basically I'm trying to ask what would be the best control for this job?

My pleasure

Is the unwinder required to keep tension on the material as it spools off? Or, is it supposed to keep some slack, but not too much, in the material as it spools off? There are a couple of ways to handle either scenario.

My go to device is always an industrial class motion controller. No, G code would not be required, you would want to write the constant surface speed code in the native motion controller code, the output to the VFD would normally be 0-10V. Exactly what that would look like would be dependant on the specific motion controller, and the overall sensor/control method chosen.

An Arduino or pic might do it. My prefered motion controller is the Galil Motion Control product line. Easy to program, and relatively inexpensive. Depending on your budget for this project, available from new from Galil or used from Ebay.

[ZeroBacklash]

My pleasure

Is the unwinder required to keep tension on the material as it spools off? Or, is it supposed to keep some slack, but not too much, in the material as it spools off? There are a couple of ways to handle either scenario.

My go to device is always an industrial class motion controller. No, G code would not be required, you would want to write the constant surface speed code in the native motion controller code, the output to the VFD would normally be 0-10V. Exactly what that would look like would be dependant on the specific motion controller, and the overall sensor/control method chosen.

An Arduino or pic might do it. My prefered motion controller is the Galil Motion Control product line. Easy to program, and relatively inexpensive. Depending on your budget for this project, available from new from Galil or used from Ebay.

Thanks again! Could the Kflop be considered an industrial grade motion controller, I beleive you can program it in C, but not sure if it has "Galil" like capabilities. Also can custom code be written for LinuxCNC along with the MESA cards?

[mactec54]

I need to understand this why is a VFD not well suited for this application?

Because of how you want to control what is happening with your process

[mactec54]

Thanks again! Could the Kflop be considered an industrial grade motion controller, I beleive you can program it in C, but not sure if it has "Galil" like capabilities. Also can custom code be written for LinuxCNC along with the MESA cards?

A simple PLC is all you need to use for your control or a stand alone indexer card like this from Dmm you can program with simple code todo what ever you want

I have a motion controller from CNCDrive, the UC400ETH. Basically I'm trying to ask what would be the best control for this job?

Then seeing you have a motion controller and a good one, that is all you need to get yourself going, and a good servo motor and drive that uses step / Dir from the control you have, this is a good place to start DMM | Technology Solutions | AC SERVO DRIVE | AC SERVO MOTOR | ROTARY ENCODER why make it more complicated than it needs to be

[Al_The_Man]

Thanks again! Could the Kflop be considered an industrial grade motion controller, I beleive you can program it in C, but not sure if it has "Galil" like capabilities. Also can custom code be written for LinuxCNC along with the MESA cards?

Kmotion/Kflop is gets pretty close to the Galil Motion products.
Closes the PID loop and enables simple ±10vdc analogue drives.
Al.

[Jim Dawson]

Thanks again! Could the Kflop be considered an industrial grade motion controller, I beleive you can program it in C, but not sure if it has "Galil" like capabilities. Also can custom code be written for LinuxCNC along with the MESA cards?

What Al_The_Man said above

ZeroBacklash, is this unwinder part of your carbon fiber winding machine? If so we should be taking a look at the whole system rather than individual pieces of it. In the end everything needs to work together with a single controller.

There are 3 primary responders to this thread and we don't always agree on the way things should be done. But between us, we proabaly have over 100 years of combined experience in motion control and machine/system design. I have to agree with mactec54, the DMM servos are nice units, are inexpensive, and if they meet your requirements for speed and torque then I would use them throughout the entire system. I'm using those for the axis drives on my lathe, also I have another custom machine in process right now and am using DMM servos for all of the functions. It's just easier when all of the hardware matches.

There is nothing wrong with using a Kflop/Kanalog system, UC400ETH, Galil, MESA, or a PLC. I personally lean towards the Galil products because I have been using them for the last 25 years or so. Given the custom nature of your requirements, you will most likely need to move away from thinking in terms of G code and actually do the programming in the native controller language. This may also require a custom user interface to operate the machine.

Your budget for this project may dictate the hardware you actually use in the end.

[Tonymc]

Most modern Vfds with 3 phase input will run with only two legs but will pull more amps the output has to be 3 phase

[ZeroBacklash]

A simple PLC is all you need to use for your control or a stand alone indexer card like this from Dmm you can program with simple code todo what ever you want



Then seeing you have a motion controller and a good one, that is all you need to get yourself going, and a good servo motor and drive that uses step / Dir from the control you have, this is a good place to start DMM | Technology Solutions | AC SERVO DRIVE | AC SERVO MOTOR | ROTARY ENCODER why make it more complicated than it needs to be

Thanks for your valued inputs Mactec54, I beleive you are an expert in automation. However with the limited expertise that I have in this field I fail to comprehend how to feed the sensor inputs (the one that wourd be sensing tension of the fibre) back to the PLC. Do simple PLC's have analog inputs?
The DMM indexer card you linked is also interesting but can't find it on their website, discontinued? perhaps?

[ZeroBacklash]

What Al_The_Man said above

ZeroBacklash, is this unwinder part of your carbon fiber winding machine? If so we should be taking a look at the whole system rather than individual pieces of it. In the end everything needs to work together with a single controller.

There are 3 primary responders to this thread and we don't always agree on the way things should be done. But between us, we proabaly have over 100 years of combined experience in motion control and machine/system design. I have to agree with mactec54, the DMM servos are nice units, are inexpensive, and if they meet your requirements for speed and torque then I would use them throughout the entire system. I'm using those for the axis drives on my lathe, also I have another custom machine in process right now and am using DMM servos for all of the functions. It's just easier when all of the hardware matches.

There is nothing wrong with using a Kflop/Kanalog system, UC400ETH, Galil, MESA, or a PLC. I personally lean towards the Galil products because I have been using them for the last 25 years or so. Given the custom nature of your requirements, you will most likely need to move away from thinking in terms of G code and actually do the programming in the native controller language. This may also require a custom user interface to operate the machine.

Your budget for this project may dictate the hardware you actually use in the end.

Thanks Jim, I beleive you and mactec54 are recommending a servo based system. I would like to understand if a sensorless vector drive + ac motor won't give sufficient accuracy for a tension unwinder / winder application?
With regard to native controller language, Galil seems to have its own native language, Kflop has C, dotnet interfaces, what other motion controllers provied software interfaces for their controllers? I mean so we can program the controller in C, C# or native high level language?

[ZeroBacklash]

Kmotion/Kflop is gets pretty close to the Galil Motion products.
Closes the PID loop and enables simple ±10vdc analogue drives.
Al.

Thanks Al. I was considering between Kflop and / or Linux CNC, advantage of Kflop being you can program it in C, C# ..

[Al_The_Man]

Re-reading the posts, I now get the idea you need to control a motor for an unwinding or spooling application?
, I would think this would be an ideal job for a Galil controller using the gearing function, IOW one encoder (mounted to the spool) would be the master and the motor controller would be the slave,
The appropriate electronic gearing ratio would be entered as needed for motor to synchronize, For a motor, a larger DC motor from a Treadmill etc withan encoder added and a A-M-C analogue drive may do the trick.
I also believe Kflop can do gearing, an email to Tom would confirm it.
Al. .

[ZeroBacklash]

Re-reading the posts, I now get the idea you need to control a motor for an unwinding or spooling application?
, I would think this would be an ideal job for a Galil controller using the gearing function, IOW one encoder (mounted to the spool) would be the master and the motor controller would be the slave,
The appropriate electronic gearing ratio would be entered as needed for motor to synchronize, For a motor, a larger DC motor from a Treadmill etc withan encoder added and a A-M-C analogue drive may do the trick.
I also believe Kflop can do gearing, an email to Tom would confirm it.
Al. .

Electronic gearing is an amazing concept thanks for re-introducing it I had somehow forgotten about it, I have been asking too many questions and some expert on this forum had referred to it, I don't remember the thread though.
What about the tension sensor, that would also be one of the inputs to the motion controller no?

[Jim Dawson]

Thanks Jim, I beleive you and mactec54 are recommending a servo based system. I would like to understand if a sensorless vector drive + ac motor won't give sufficient accuracy for a tension unwinder / winder application?

The 3 phase motor / VFD combination should give more than adequate accuracy for an unwinder. But if you are using servos for the rest of the system, using a servo motor for the unwinder just makes sense for control consistency throughout the system. The cost difference would be minimal if any.

With regard to native controller language, Galil seems to have its own native language, Kflop has C, dotnet interfaces, what other motion controllers provied software interfaces for their controllers? I mean so we can program the controller in C, C# or native high level language?

All of the industrial class controllers have a software interface, many can be programmed with a .net type interface. I know that Rexroth and Allen Bradley require their own, very expensive, development software, the Galil controller can be programmed in NotePad or any text editor. I don't know what is available in the hobby class controllers.