before finished two-hour simulation. For that, we will introduce two solutions for the original systemA: First solution :We fined that the first line overloaded was line 2-4.for that we have to let the power be transmitted through other line from bus 2 to bus 4, but we can not put it in parallel to the original line. There is another way to do that, by increasing the number of the circuit from 1 to 2.By doing this the power that transmitted through line 1-2 will be divided into two line. But the other lines stayed the same. After that I changed the number of the circuit in the other lines and the transformers. By this way the system works for two hours and this means the power transmitted through double line not in one line. But, the per-unit voltage at bus 3, and 4 were not in 1.05-0.95 ring. To increase the per-unit voltage I put capacitor bank at bus 3 and 4. Adding capacitor bank means we supply extra reactive power to these buses. The rating values for both capacitor bank is 80(MVAR).By doing that the system works for two hours without any problem as in the next diagram.B: Second Solution:From the bus-data table we fined that bus 2 has a limiting rang of (MVAR) between 20-60 (MVAR) and from the original single-line diagram we fined that the line 2-4 was the first line overloaded for that we can remove this line as the second solution. But, in this case the power will be supplies by the other lines to bus 2 and 4, which will caused extra power through the other lines that will let the other lines be overloaded. We can solve this problem by changing the circuit number from one to two, this means we doubled the lines and the transformers and this will transmit the power through two parallel lines no in one. The system after these change works without any overload in any line. But, the per-unit voltage at bus 2 and 4 were not in the rang. For that we put capacitor banks at bus 2 and 4 with rating value 80 (MVAR) each. After all thes...
