Selection of Lines to Be Switched to Eliminate Overloaded Lines Using a Z-Matrix Method

There are many ways in which a system can be adjusted to compensate for an overloaded line. Earlier studies have shown that shifts in generation or phase shifter adjustments can be calculated to correct an overload. These corrections are based on an analytical solution of the system. Many algorithms have been developed to use these techniques in optimal power flow solutions. Generation schedules are based on economic dispatch and any deviation from the proper schedule to eliminate overloads will result in an increase in production costs. There have been a considerable number of papers in the literature that have presented methods of solving large problems, such as the power system load flow problem, using different approaches with a large amount of numbers in storage and more computer time. Methods have been developed to identify overloaded lines and to select one or more lines to be removed in order to reduce the overload in a power system. Recent research in reference [1] indicated that a simple method of redirecting power flow to reduce the overload in a line is to selectively switch the network. A line can be added to or removed from the system in order to cause a shift in the power flow and to eliminate the overload. The selection of a line to be switched is a complicated process. The addition or removal of a line must not cause any other overloads on the system as it eliminates the original overload.