V/F Flying Start And Vvw; Vector Flying Start; P0202 = 3 - WEG CFW-11 Programming Manual

Functions Common to All the Control Modes

12.7.1 V/f Flying Start and VVW

In the V/f and VVW mode, the inverter imposes a fixed frequency at the start, defined by the speed reference,
and applies a voltage ramp defined at the parameter P0331. The Flying Start function will be activated after the
time adjusted in P0332 elapses (to allow the motor demagnetization), every time a "Run" command is driven.

12.7.2 Vector Flying Start

12.7.2.1 P0202 = 3

The behavior of the Flying Start function (FS) in the sensorless mode during acceleration and reacceleration
can be understood from the
The Figure 12.6 on page 12-14
with stopped motor shaft and small P0329 value (not optimized).
Operation analysis:
1. The frequency equal to the adjustment P0134 is applied with a current equal to 0.9xP0401 (I/f control).
2. The frequency is reduced down to zero using the ramp given by: P0329 x P0412.
3. If the speed is not found during this frequency scan, a new scan in the opposite speed direction is initiated,
in which the frequency goes from [-P0134] to zero. After this second scan the FS is finished and the control
mode changes to vector sensorless.
The Figure 12.6 on page 12-14
shaft already running in the desired direction, or with stopped shaft and an already optimized P0329.
Operation analysis:
1. The frequency equal to the adjustment P0134 is applied with a current equal to 0.9 x P0401 (I/f control).
2. The frequency is reduced using the ramp given by: P0329 x P0412 until reaching the motor speed.
3. In this moment the control mode changes to vector sensorless.
NOTE!
In order that the motor speed is found in the first scan, proceed with the P0329 setting in the
following manner:
1. Increase P0329 using 1.0 steps.
2. Enable the inverter and observe the motor shaft movement during the FS process.
3. If the shaft rotates in both directions, stop the motor and repeat the steps 1 and 2.
NOTE!
The used parameters are P0327 to P0329.
NOTE!
When the general enable command is activated, the motor magnetization will not occur.
12
NOTE!
For a better performance of the function, the activation of the braking without losses is recommended
by setting the parameter P0185 according to the
12-12
Figure 12.6 on page 12-14.
(b) shows the behavior of the speed reference when the FS function is started
(c) shows the speed reference when the FS function is initiated with the motor
Table 11.9 on page 11-32.