Control based doubt

Wind & Water Controls
1

Dear all

i am manikandan, working for control of NREL 5MW Offshore wind turbine, i am having following doubt , please help me

For power maximization in region 2 -energy capture is maximized by regulating generator speed, also need to limit plat form movement , here only i am having doubt , which came from discussions with one of my friends.

1.how platform motions related with maximization power problem, what is relation , if we using some control techniques to limit platform motion-in what way it will help to improving power what is the relation or physics behind it , kindly visualize the problem

2.second question -if i will implement LQR or PID or Sliding Mode controls, how i am physically incorporating in real time environment(I want to tel , i am familiar FAST simulation and numerical analysis but not in experimental scenario )

i request, please help me to sort out the problem

2

Dear Mani,

Minimizing the motion of the platform is likely more important for minimizing loads than maximizing power. (The inertia and gravity loads from large motion could increasing the structural loading of components.) The impact of motion on power capture is likely only a problem for very large motions such that (1) the swept area of the rotor normal the wind is being dramatically reduced by the platform motion, (2) it is not possible to maintain optimal tip-speed ratio in region 2, or (3) it is not possible to maintain suitable speed regulation in region 3.

I’m not sure I understand your section question.

Best regards,

3

Dear Jason Jonkman,

Thanks for your immediate reply, my second question is ,

if i will implement the PID controller to limit the pitch angle or control the generator speed(by using fortran codes or simulink model i am able to do it ), in experimental or real time environment , how to implement this type of active control to limit pitch angle in real time turbine?,

If i will implement MIMO PID to control to limit platform motion with generator speed in real time model , how can i implement in practically , like if am using some interfacing software to link my model ,which device will receive this computer output , and how it establish the command passed from the code

4

Dear Mani,

On a real machine, the controller logic would likely be implemented in hardware, e.g., with a PLC. Alternatively, we’ve set up our controls research turbines at NREL (the CARTs) to interact directly with LabVIEW for implementing controls.

Best regards,

5

Dear Jonkman
Thanks for timely help

6

Dear Jonkman,

I’ve been working on the PID Gains Scheduling control design for the WindPact 1.5 MW wind turbine. Following the procedure published on [url]http://www.nrel.gov/docs/fy08osti/42437.pdf[/url] page 32, i built a clásic PID controller and a Gain Scheduling PID controller. As per this document, it should be a difference for several step wind response between the clásic and gain scheduling. Please find below the graphics for each case.

ClasicPID.JPG
ClasicPID.JPG616×607 26.6 KB

GSPID.JPG
GSPID.JPG645×602 27.5 KB

Additionally, please fin attatched the Gain Scheduling Diagram i created on Simulink.

PID_GS_Diagram.JPG
PID_GS_Diagram.JPG768×256 15.4 KB

Once explained the situation i have several questions:

  1. Did i follow correctly the procedure?
  2. Am i missing something on the diagram?
  3. Should be there any difference between the graphics?

thanks in advance!