Menu

Topic-icon Power saving

More
1 year 5 months ago #29534042 by glmnet
Power saving was created by glmnet
What are my options to reduce power consumption while the motors are not running?
My device has an electromagnetic brake connected to the motor shaft, so when I activate the brake (remove power to it) the brake engages. I've found out though that while the brake is not set the motors are quite hard to turn, like an electronic brake controlled by the driver.
Are there options to disable the power output stage?
I guess I could remove the power to the controller with a contactor or something else.
I am going to lose digital output control if I do this? In that case can I disable MOSFET output but keep digital output power?
Thanks.

Please Log in or Create an account to join the conversation.

  • Gabriel_Isko
  • Gabriel_Isko's Avatar
1 year 5 months ago #29534043 by Gabriel_Isko
Replied by Gabriel_Isko on topic Power saving
Can you clarify - are you trying to reduce power output from your motors or are you definitely trying to shut down the power output entirely? In open loop mode at 0 motor command in a brushless controller, the controller shouldn't be outputting any current, but the motor will still resist motion because its phase outputs are still tied together. This actually helps regenerate energy from the motor, and can be used to charge batteries.

In our controller, the power output stage should only be disabled (all output FETs in float state) during a fault condition. There are two ways I can think of to achieve this:

1) Throw an Emergency Stop. This isn't recommended for non-emergency conditions, but it is the only way to achieve the disabled condition internally from our controller.

2) Cut Power to VMot with a contactor. You mentioned this in your post. If VMot voltage is lower than the specified minimum for the controller, it will send the controller into an undervoltage fault condition and disable the motor output.

All of our Motor controllers implement a PwrCtrl bus that allows the logic stage of the controller to be powered even when sufficient power isn't available on VMot. Voltage available on PwrCtrl is not available to the motor output stage.

I recommend taking a look at the wiring recommendations in Sections 1 and 2 of our User Manual .

Please Log in or Create an account to join the conversation.

More
1 year 5 months ago #29534049 by glmnet
Replied by glmnet on topic Power saving
Thanks Gabriel

I'm trying to reduce power when AGV is not moving. I can feel the Roboteq Controller getting hot even when it was just powered up and set idle there.
May be the key here is the Open Loop mode, currently I always have the wheels in Closed Loop Speed. Should I switch the motor mode every time I am not going to command it to move?
Which commands should I use in this case?
Thanks again.

Please Log in or Create an account to join the conversation.

  • Gabriel_Isko
  • Gabriel_Isko's Avatar
1 year 5 months ago #29534052 by Gabriel_Isko
Replied by Gabriel_Isko on topic Power saving
You can change the operating mode of each motor output channel using the MMOD configuration command. It's documented starting on page 328 of our User Manual .

It's odd that the controller is drawing current at rest in closed loop speed mode. Do you know what the motor power and motor amps are when the AGV is stopped?

Please Log in or Create an account to join the conversation.

Moderators: tonysantoni
Time to create page: 0.091 seconds
Go to top