RIGENERATIVE
SINUS PENTA
APPLICATION
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3.3.
REFERENCE AND REGULATORS MENU
3.3.1.
O
VERVIEW
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. 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 error 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.