Zbus using bus building algorithm

Zbus for a particular n bus power system is found

There are four types of modifications possible:

1. Type 1 modification: between a new bus and the reference bus
2. Type 2 modification: between a new bus and an old bus
3. Type 3 modification: between an old bus and the reference bus
4. Type 4 modification: between two old buses

For each type of modification, the code performs the necessary calculations to update the Z-bus matrix.

After each modification, the code displays the updated Z-bus matrix using the disp function.

Finally, the code prints a message indicating that the Z-bus matrix has been calculated using the bus building algorithm and displays the calculated Z-bus matrix using the disp function.

Overall, this code implements the bus building algorithm for calculating the Z-bus matrix for a power system network. The code uses MATLAB functions such as xlsread, zeros, disp, and input to read data from an Excel sheet, initialize the Z-bus matrix, display the output, and prompt the user for input.