Start-Up In The Vector Modes Sensorless And With Encoder - WEG CFW-11 Programming Manual

Vector Control
Description:
The response time of the droop function is adjusted using P0334, which defines the constant time applied to the
filter used in the torque current.
The DROOP value in rpm can be obtained by means of the following equations:
iqf x P0333 x P0295
=
DROOP
When n > Nrated, the equation above must be multiplied by a ratio-corrector factor; thus, the value of the
ref
corrected DROOP is given by:
n
=
DROOP_cor
P0402
Where:
n – total speed reference
ref
iqf – torque current (iq) filtered according to the setting of P0334
P0333 – DROOP factor (%)
P0295 – HD rated current of the inverter
P0401 – motor rated current
P0402 – motor rated speed in rpm
The approximate calculation of the torque current (iq) is given by:
P0009 x
P0401
=
iq
P0295
For the DROOP calculation purposes, the iqf value can be considered equal to the iq determined in the expression above.
The influence of the DROOP function in the determination of the speed may be checked in
NOTE!
The setting of the DROOP factor (P0333) depends on the dynamics of each application, and it should be
set during on-load operation/installation. An empirical method to define the value of P0333 would be:
1. Set P0333 to zero and keep P0334 in its factory setting value.
2. Start the system operation with load and monitor the output currents of the inverters.
3. Modify the value of P0333, setting it to negative values until the output current values of the
4. In case it is necessary that the DROOP response to the speed and load variation be slower, the

11.9 START-UP IN THE VECTOR MODES SENSORLESS AND WITH ENCODER

NOTE!
Read the whole CFW-11 user's manual before installing, powering or operating the inverter.
Sequence for installation, verification, powering and start-up:
11
a) Install the inverter: according to the chapter 3 – Installation and Connection of the CFW-11 user's manual,
wiring all the power and control connections.
b) Prepare the inverter and apply power: according to the section 5.1 - Prepare for Start-Up, of the CFW-11
user's manual.
11-34
x 0.1 [rpm]
P0401
ref
x DROOP [rpm]
- P0410
2 2
inverters are similar.
value of P0334 must be increased.
Figure 13.8 on page 13-33.