Can anybody help me with the design of PI-IPC?

Hi all,

I am doing some research about Individual Pitch Control (IPC). Now I am trying to design an IPC system based Proportional-integral (PI) method and validated on the FAST software. I am using NREL 5MW wind turbine with baseline generator torque and pitch controller. My design is shown as the attachment.IPC design.jpg

Before the Coleman transformation, the flapwise bending moments are filtered with a notch filter tuned to the 1P frequency and scaled. After the reverse transformation, the signals are filtered again by a low-pass filter to obtain smooth control signals. According to the above design, the parameters of the I controllers has been tuned to the best. However, the performance of IPC controllers is not good. The magnitude of the flapwise blending moment of blade 1 is barely reduced.

Is there anything wrong with my IPC design? Can you help me with the possible faults and possible improvement methods? Thanks a lot.

Yanhua