Motor Control; Common Functions; Ramps - WEG CFW100 Programming Manual

8 MOTOR CONTROL

The inverter feeds the motor with variable voltage, current and frequency, providing control of the motor speed.
The values applied to the motor follow a control strategy, which depends on the selected type of motor control and
on the inverter parameter settings.
The selection of the proper control type for the application depends on the static and dynamic requirements of torque
and speed of the driven load, that is, the control type is directly connected to the required performance. Additionally,
proper configuration of the selected control mode parameters is essential to reach maximum performance.
The inverter is equipped with three control modes for the three-phase induction motor, that is:
V/f Scalar Control: for basic applications without output speed control.
Quadratic V/f Scalar Control: for applications that reduce motor and inverter losses without regulation of the
output speed.
VVW Control: for applications that need high performance in the control of the output speed.
Section 8.2 CONTROLE ESCALAR V/f on page 8-18
these kinds of control, related parameters and directions regarding the use of each of these modes are described
in details.
P202 - Type of Control
Range: 0 = V/f
1 = Quadratic V/f
2 to 4 = Not Used
5 = VVW
Properties: cfg
Description:
This parameter selects the kind of three-phase induction motor control used.

8.1 COMMON FUNCTIONS

This chapter describes the functions common to all inverter control modes V/f and VVW and that interfere in the
drive performance.

8.1.1 Ramps

The inverter ramp functions allow the motor to accelerate or decelerate faster or slower. They are adjusted by
parameters that define the linear acceleration time between zero and the maximum frequency (P134) and the time
for a linear deceleration from the maximum frequency zero.
In the inverter, three ramps with different functions were implemented:
st
1 Ramp - standard for most functions.
nd
2 Ramp - it may be activated by the user, according to the drive requirement, by means of the inverter command
word or by a digital input.
Emergency Ramp - it is used for the inverter internal protection functions, such as: current limitation, DC link
regulation, etc. The Emergency Ramp has priority over the other ramps.
and Section 8.3 CONTROLE VVW on page
MOTOR CONTROL
8-25, each of
Micro Mini Drives | 8-1
8