Economic Dispatch Using Lambda Itteration Method Neglecting Generation Limits & Transmission Losses Using Matlab

a)    Calculation Using Lambda Iteration Method

Lambda Iteration method Uses an Initial Assumption of Lagrange Multiplier and uses Continuous iterations to find correct value of Lambda. This correct value is found at Satisfaction of Demand.

Steps of Calculation Include

Ø  1^st Step to Solve a Dispatch Problem is to write cost characteristic equations of committed units for Meeting Demand .(Refer To Equal Incremental Cost Criteria)

Ø  Assume a Value of Lagrange Multiplier and Calculate Generation Sharing (Generation Allocation) at that value of Lambda 

Ø  Calculate Difference in Value of Power demand and Total Generation.(Error)

MATLAB Program

clc

clear all

Pd=input('Total Power Demand = ');

Lambda=input('Assumed Value of Lagrange Multiplier = ');

n=input('No of Units Commited to Satisfy Demand = ');

x=Pd*0.10:10:Pd;

for i=1:n;

    a=input('No Load Speed Cost of Unit($/h) = ');

    b=input('Slope of linear line of unit ($/MWh) = ');

    c=input('Coefficient of 2nd order term of Unit(($/h)/MW^2) = ');

    A(i,:)=[a b c];

    y=[2*c*x+b];

    plot(x,y)

    hold on

end

a=A(:,1);

b=A(:,2);

c=A(:,3);

DelP=5;

iter=0;

while abs(DelP) >=0.01

    iter=iter+1;

    P=(Lambda-b)./(2*c);

    DelP=Pd-sum(P);

    X=sum(1./(2*c));

    Del_Lambda=DelP/X;