We're back at another episode of Problem Solved. I'm Jake. And I'm Carlton. And we
are going to tackle another topic. What's the topic for today? The quick stop
function inside an s6 Drive. All right let's do this.
So Carlton, why don't you explain a little bit of what the quick stop
function is in a VFD. Yeah, Jake. So the quick stop function is a function that's
available in KEB VFD products that is used to rapidly stop a motor from normal
operation. The quick stop function is normally employed after an abnormal
condition or a system failure. Quick stop is not to be confused with an
emergency stop, however. It's just a way to rapidly decelerate the motor from its
normal condition quicker than normally stopping the motor. Where and when would
this quick stop function be used? Yeah, Jake. Really, the quick stop function is
best suited whenever you want to rapidly decelerate or bring the motor to a stop
in a quick fashion. If something outside of the scope of the S6 or the motor were
to fail, or an operation were to fail, or a part. The S6 can be quickly decelerated
using the quick stop function. If you have long and extended deceleration
rates per a normal operation and you want to shorten those and bring the
motor to a very controlled stop, the quick stop function is also very
beneficial. Excellent, so let's dive into it. Can you demonstrate how quick
stop works with our demo? Of course, let's do it.
In order to configure and enable our quick stop function there are a few
parameters we need to set in our COMBIVIS 6 software. so let's get to it.
the first parameter we're going to look at is "state machine properties". And
opening this parameter we will need to enable quick stop by setting this bit to
"on." This will activate the quick stop function inside the S6 drive for us to use.
Next we need to determine the quick stop stopping method, and we do so by
using the parameter "quick stop option code." These three parameters at the
bottom of the parameter list configure the quick stop mode to be selected via
digital input, rather then over the control word. Now depending
on the "quick stop option code," we can program the quick stop function to
decelerate following the "fault reaction ramp" that is presented here. Depending on
the system the quick stop function and fault reaction ramp can be configured to
be as aggressive or soft as desired. For example, we can have the deceleration
ramp be much more aggressive and sharp than the acceleration ramp. And as you
can see here the deceleration ramps are more aggressive and sharper than the
acceleration ramps. On the other hand, we can also have the deceleration ramps
be more elongated and gradual than their acceleration ramps. And as you can see
here the s-curve is presented for the deceleration ramps are much more gradual
and elongated than the acceleration ramps. When using the quick stop function
in the S6 there are essentially two methods that can be used to bring the
motor to a stopped position. In the first method, the drive immediately removes
output to the motor and allows the motor to coast to a stop. This is really useful
in any horizontal application, mixer, rotary wheel, or any system that has low
inertia, but some friction to be able to stop the motor pretty quickly. So this is
an example of quick stop method one, where modulation is just removed from
the motor. In this case since there's no load the motor will come to a quick stop.
But if there was high inertia the motor would Coast and spin for a little while
until it stops. In the second method of the quick stop mode, you can actually
have the quick stop deceleration follow the fault reaction ramp. This method is
beneficial because the drive can also provide some holding torque as well - if
encoder feedback is used - which is really beneficial for a vertical axis
application, to provide some holding torque before a brake is applied.
This ramp can be programmed to be as aggressive or soft as desired for the
application.
So, hopefully you learned a little bit about the quick stop function in a VFD.
If you enjoyed this video, like and subscribe, follow us on social media, and
check us out at KEBamerica.com Have a great day!