Sensorless Vector control; Sensorless Vector control Vs V/f control
Variable frequency drive Sensorless Control
recurrence drive designs of the sensorless control contain the accompanying
extra capacities, which supplement the conduct as indicated by the
parameterized V/f trademark.
subordinate distinction between the reference speed and the genuine speed of
the 3-stage engine is alluded to as the slip. This reliance can be remunerated
by the present estimation in the yield periods of the variable recurrence
The enactment of
Operation Mode for the slip remuneration empowers as speed control without
input. The stator recurrence and speed are revised relying upon the VFD stack.
recurrence drive slip pay is enacted amid the guided appointing. The Stator
Resistance is required to guarantee a right capacity and is estimated amid the
On the off
chance that no guided dispatching is executed, the slip pay can be enacted
physically. In these cases, enter the VFD esteem for the Stator Resistance
physically as indicated by the engine information sheet.
recurrence drive control conduct of the slip pay must be streamlined through
the parameters on account of particular applications. The VFD parameter
Amplification decides the rectification of the speed and the impact of the slip
pay relatively to the difference in stack. Parameter Max. Slip Ramp
characterizes the most extreme recurrence change every second keeping in mind
the end goal to stay away from an over-burden on account of a heap change.
parameter Frequency Lower Limit decides the recurrence as from which the slip
remuneration winds up dynamic.
Current limit value controller Through a heap subordinate speed control, as far as
possible esteem controller guarantees that the VFD framework isn't over-burden.
This is reached out by the astute current points of confinement portrayed in
the past section. As far as possible esteem controller decreases the heap on
the VFD, e.g. amid increasing speed, by halting the quickening incline. The
turn off of the variable recurrence drive which happens when the increasing
speed slopes have been set at an exorbitant inclination is in this way avoided.
recurrence drive control conduct of as far as possible controller can be set by
means of the relative part, parameter Amplification and the coordinating part,
parameter Integral Time. In the event that, in uncommon cases, advancement of
the controller parameters is required, continue with the accompanying advances:
•Change parameter Current Limit
with a major advance, dissect the adjustments in the Scope.
•For a more unique conduct
increment Amplification or potentially diminish Integral Time.
•For a less powerful conduct
diminish Amplification and additionally increment Integral Time.
Behavior in motor operation: On the off chance that the VFD current set by means
of parameter Current Limit is surpassed, the initiated current point of
confinement esteem controller will lessen the yield recurrence until the point
when as far as possible is never again surpassed. The yield recurrence is
decreased as a most extreme to the recurrence set by the parameter Frequency Limit.
On the off chance that the present esteem dips under the variable recurrence
drive Current Limit, the yield recurrence is raised back to the reference
Behavior in generator operation: In the event that the VFD current set through
parameter Current Limit is surpassed, the enacted current breaking point esteem
controller will expand the VFD yield recurrence until the point when as far as
possible is never again surpassed. The yield recurrence is expanded, as a most
extreme, to the set Maximum Frequency. On the off chance that the current is
underneath the variable recurrence drive Current Limit, the yield recurrence is
decreased to the required reference esteem once more.
In a Scalar drive
(V/Hz just), the drive releases a Voltage a Frequency as indicated by the speed
you have chosen. In any case, the VFD has no clue regardless of whether that
had the coveted impact on the engine and load; it does it's thing and trusts in
the best. On the off chance that the heap ends up being more than the engine
can deal with, the engine backs off, the slip increments and the engine pulls
more present and makes more torque, yet this is a "messy" process,
best case scenario. So basically the drive gives a yield, the heap makes a
"blunder" in execution, yet the drive doesn't generally make a move.
The final product isn't generally compelling.
control, the VFD utilizes input from the engine to see the blunder, at that
point to decide the correct vector of voltage and recurrence to deliver
precisely what is expected to adjust the mistake. It has a rapid processor to
do the math and rapidly change the yield voltage and recurrence example to
augment the torque and/or fix the speed control. Along these lines, you can
work an engine at Breakdown Torque at any speed, even zero if vital.
can be proficient with outer input from encoders called Closed Loop Vector or
Field arranged Control (FOC), as you are doing, or with what is called
"Sensorless Vector Control" (SVC) or "Open Loop Vector
Control". The two names are actually off base; there is dependably a
sensor and it is constantly shut circle. Yet, the distinction is in that what
is called SVC utilizes exceptionally delicate current sensors within the drive
to observe precisely what is happening, and contrasting it with a scientific
model it has made of the engine amid setup (the "tuning"
methodology). The two techniques work fine, yet the SVC has one restriction; it
can't watch the engine execution if the engine isn't moving, i.e. zero speed;
like what you would need with a lift. FOC, where you have the encoder
criticism, can do that.
So for you,
Starting Torque will dependably be most astounding and repeatable with Vector
control of any kind contrasted with Scalar control. On the off chance that you
require it at Zero Speed since you are expecting to discharge a brake and you
need full torque to start with, at that point you require FOC. If not, SVC will
likely work fine and you won't require the encoder.