SINUS PENTA
GUIDE TO THE
REGENERATIVE APPLICATION
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150
5.3.
Reference and Regulators Menu
5.3.1. Overview
This menu contains the parameters relating to the DC-bus voltage control.
The setpoint is set for the DC-bus voltage stabilization. This depends on the mains voltage; always set a
value exceeding the max. rectified mains voltage. The recommended values are given in the section
covering the first startup of the equipment.
A PI (proportional-integral) regulator allows the DC-bus voltage to be kept constant. Factory setting suits
most applications. However, it can be changed when the DC-bus voltage is unsteady or when overvoltage
occurs due to sudden variations of the motor drive load. Increasing the proportional term allows a quicker
response of the system, but can cause fluctuations at constant speed. For a quicker response of the
regulator to power transients and for a steady control of the equipment at constant speed, you can use the
dual parameterization available for the regulator and set two error thresholds percent and two
proportional/integral gain sets.
The PI regulator will then have the following features:
1) For wrong values equal to or lower than the min. threshold (
P514
), the regulator parameters
P510
and
P511
will be used.
2) For wrong values equal to or higher than the max. threshold (
P515
), the regulator parameters
P512
and
P513
will be used.
3) For wrong values ranging from the min. threshold (
P514
) to the max. threshold (
P515
), the equipment will
use the following terms:
Integral coefficient
= (1/
P511
) + [(err
–
P514
)* (1/
P513
– 1/
P511
) / (
P515
–
P514
)]
Proportional coefficient
=
P510
+ [(err
–
P514
)* (
P512
–
P510
) / (
P515
–
P514
)]
The error percentage is computed based on the max. value that can be set as a DC-bus voltage reference
(
P500
):
Error% = (
P500
–VDC measured)/(Max
P500
)
NOTE
If the min. error threshold is the same as the max. error threshold (
P514
=
P515
), the PI regulator will only use the proportional term (
P510
) and the
integral term (
P511
) relating to the minimum error. The remaining terms of
the PI regulator become active and can be displayed only if a max. error
threshold greater than the min. error threshold (
P515
>
P514
) is set up.
