# MATLAB Application for Load Frequency Dynamics of Two Area Power Systems | EE1404 – Power System Simulation Laboratory

AIM:
To become familiar with modelling and analysis of the frequency and tie-line flow
dynamics of a two area power system without and with load frequency controllers (LFC) and to
design better controllers for getting better responses.

THEORY:
Active power control is one of the important control actions to be perform to be normal
operation of the system to match the system generation with the continuously changing system
load in order to maintain the constancy of system frequency to a fine tolerance level. This is one of
the foremost requirements in proving quality power supply. A change in system load cases a
change in the speed of all rotating masses ( Turbine – generator rotor systems) of the system
leading to change in system frequency. The speed change form synchronous speed initiates the
governor control (primary control) action result in all the participating generator – turbine units
taking up the change in load, stabilizing system frequency. Restoration of frequency to nominal
value requires secondary control action which adjust the load - reference set points of selected (
regulating) generator – turbine units. The primary objectives of automatic generation control
(AGC) are to regulate system frequency to the set
nominal value and also to regulate the net
interchange of each areas to the scheduled value by adjusting the outputs of the regulating units.
This function is referred to as load – frequency control(LFC).

PROCEDURE:
1. Enter the command window of the MATLAB.
2. Create a new Model by selecting File - New – Model
3. Pick up the blocks from the simulink library browser and form a block diagram.
4. After forming the block diagram , save the block diagram.
5. Double click the scope and view the result.

EXERCISE:
1. A two area system connected by a tie line has the following parameters on a 1000MVA
common base
The units are operating in parallel at the nominal frequency of 60Hz. The synchronizing power
coefficient is computed from the initial operating condition and is given to be Ps = 2 p.u. A load
change of 187.5 MW occurs in area1.
(a) Dertermine the new steady state frequency and the change in the tie-line flow.
(b) Construct the SIMULINK block diagram and obtain the frequency deviation response for
the condition in part(a).