How To Design Load Frequency Control of
Thermal/Hydro Power Plant Using Transfer
Functions in MATLAB/SIMULINK By Dr. J. A. Laghari
Power System
Modelling in MATLAB
This example is taken
from the book Power System
Analysis by Hadi Sadat.
Chapter 12,
Example 12.1.
 Example
An isolated power station has the following parameters.
Turbine Time Constant, Tt = 0.5 seconds,
Governor Time Constant, Tg = 0.2 seconds,
Generator Inertia Constant, H = 5 seconds,
Governor Speed Regulation
= R per unit.
The load varies by 0.8 percent for a 1 percent change in frequency, i.e. D = 0.8.
The governor speed regulation is set to R = 0.05 per unit. The turbine rated power
is 250 MW at nominal frequency of 60 Hz. A sudden load change of 50 MW (ΔPL =
0.2 per unit) occurs.
Construct the Simulink block diagram and obtain the frequency deviation response.
Solution:
 Transfer Function Model of Power Plant
Solution:
 Steady State Frequency Deviation
The governor speed regulation R = 0.05 per unit. Therefore, 1/R will become
1
1

 20
R 0.05
The steady state frequency deviation as calculated in the example is
f  0.0096 p.u.
Solution:
 Steady State Frequency Deviation
The steady state frequency deviation in Hertz will be equal to
f Actual  f p.u .  f Base
f Actual  0.0096  60  0.576 Hz
The steady state frequency in Hertz is given by
f Actual  f original  f Actual
f Actual  60  0.576  59.424 Hz
Solution:
 Load Change of 50 MW
The turbine rated power is 250 MW. A sudden load change of 50 MW
occurred. The value for step input function will become.
50
PL 
 0.2 p.u.
250
PL  0.2  250  50 MW
PL  250  50  300MW
 Research Projects Based on This Topic
Load Frequency Control of Thermal/Hydro Power
Plant Using PID Controller Tuning with Bode Plot.
Load Frequency Control of Thermal/Hydro Power
Plant Using Fuzzy Logic Controller.
Load Frequency Control of Thermal/Hydro Power
Plant Using Artificial Neural Network.
Load Frequency Control of Thermal/Hydro Power
Plant Using Radial Basis Function Neural Network.
 Research Projects Based on This Topic
Load Frequency Control of Thermal/Hydro Power
Plant Using Probabilistic Neural Network (PNN).
Load Frequency Control of Thermal/Hydro Power Plant
Using Adaptive Neuro Fuzzy Inference System (ANFIS).
Load Frequency Control of Thermal/Hydro Power
Plant Using Support Vector Machine (SVM).
 Research Projects Based on This Topic
Automatic Generation Control of Two Area Power
System Using PID Controller Tuning with Bode Plot.
Automatic Generation Control of Two Area Power
System Using Fuzzy Logic Controller.
Automatic Generation Control of Two Area Power
System Using Artificial Neural Network.
Automatic Generation Control of Two Area Power
System Using Radial Basis Function Neural Network.
 Research Projects Based on This Topic
Automatic Generation Control of Two Area Power
System Using Probabilistic Neural Network (PNN).
Automatic Generation Control of Two Area Power System
Using Adaptive Neuro Fuzzy Inference System (ANFIS).
Automatic Generation Control of Two Area Power
System Using Support Vector Machine (SVM).
THANK YOU VERY MUCH