Question

A power system consists of $2$ areas (Area $1$ and Area $2$) connected by a single tie-line. It is required to carry out a load flow study on this system. While entering the network data, the tie-line data (connectively and parameters) is inadvertently left out. If the load flow program is run with this incomplete data.

• A. The load flow will converge only if the slack bus is specified in area $1$
• B. The load flow will converge only if the slack bus is specified in area $2$
• C. The load flow will converge only if the slack bus is specified in either area $1$ or area $2$
• D. The load flow will not converge if only one slack bus is specified.

Answer 1

The correct option is D The load flow will not converge if only one slack bus is specified.

For load flow study to converge there must be one slack bus in the system. As while entering the network data the tie-line data is not considered, two areas will now be treated as seperate areas hence two slack bus (one in each area) are required.