Abstract:
In this research, a non-linear model for the guide vane electro hydraulic actuator
of turbine no.4 at Rosaries Hydro Power Station has been developed using
MATLAB/SIMULINK integrated environment, and the performance of the model
is compared with the real plant using a state feedback controller and a PID
controller with the same (PID) gains as built in the real plant. The performance
of the two controllers is investigated.
To understand the dynamic behaviors of the system, it has been represented by
3ed order differential equations defining the dynamics of plant, and using a fact
that the dynamic pressure changes in the hydraulic cylinder chambers becomes
linearly dependent on cylinder chambers volumes above and below some
prescribed cut off frequencies, the order of system equations reduced to 2ed
order. Then these equations were used to design the state feedback controller,
so as to control the non-linear model.
For the position control of the single rod hydraulic actuator, state feedback
gains are determined by using the linear reduced order system equations.
The dynamic performance of the system is investigated by running open loop
and closed loop frequency response and step response tests.