WEG CFW11 Applications Manual page 21

Parameters Description
5.1.2 Voltage PID Controller
This group of parameters allows the user to configure the PID controller gains for the DC voltage control
supplied by the photovoltaic modules. The PID controller always will attempt to search the work point defined
by Tracking Setpoint and for this will act on the output frequency of the motor.
P1024 – Voltage PID Proportional Gain
Adjustable 0.000 to 32.000
Range:
Properties:
Access groups via HMI:
Description:
This parameter defines the proportional gain value of the PID controller for the DC voltage control.
P1025 – Voltage PID Integral Gain
Adjustable 0.00 a 320.00
Range:
Properties:
Access groups via HMI:
Description:
This parameter defines the integral gain value of the PID controller for the DC voltage control.
P1026 – Voltage PID Derivative Gain
Adjustable 0.000 to 32.000
Range:
Properties:
Access groups via HMI:
Description:
This parameter defines the derivative gain value of the PID controller for the DC voltage control.
5.1.2.1 PID Controller Gain Adjustment
In controlling pumping systems, a Proportional-Integral (PI) velocity regulator is sufficient to achieve good
control performance. The proportional gain K
controller response is not satisfactory, i.e. if there are oscillations in the DC Bus Voltage (P0004) around the
setpoint, very slow response time or constant error in relation to the setpoint. Here are some suggestions for
regulator adjustment:
■ DC Bus oscillation: In most cases this is due to excessive gain of the PID controller, reduce the K
gains gradually and observe the response;
■ Very slow response time: Increasing the K
system may have surges;
■ Constant error in the output: In this case, increasing the gain K
ie when the output cannot reach the setpoint. Excessive K
decrease the gain K so that the total gain is reduced while maintaining gain K
P
5.1.2 Cloud/Load Controller
This group of parameters allows the programmer to enable and adjust the gain of the cloud/load controller.
The controller acts together with the DC Voltage PID controller, when the error between the SP voltage and
the DC Link voltage are above a threshold (P1038), the controller is enabled and will contribute the DC Voltage
PID, adding a value to its output according to a gain setting (P1039).
SPLC
SPLC
SPLC
(P1024) and integral K
P
gain the system must respond faster, however from a limit the
P
Application Default Setting:
Application Default Setting:
Application Default Setting:
(P1025) must be changed if the
I
eliminates the constant error of the output,
I
gain can generate oscillations at the output, then
I
.
I
1.000
20.00
0.000
and K
P I
Solar Pump Drive | 21