Line switching reconfiguration corrective action for overloads in power systems

This paper proposes an on line technique to select the most effective lines to be switched out of service to reduce overloads in other lines in power systems. A partial rescheduling of spinning reserve generation is then carried out to a further reducing of line overloads using a proposed formula. A contingency analysis of switchable lines is introduced based on the sensitivity parameters of the N-matrix. Two proposed indicators are presented of line overloading following a line outage: the first indicator is derived from the N-matrix after a line outage, while the second indicator is derived from the N-matrix before and after line switching. The second indicator provides an estimate of line power flows after one or more lines have been switched out of service. A proposed recursive of the N-matrix is used to reflect the line switched out. The overall technique provides a simple new tool, with a substantial saving in computer time, which could be used in a control center to aid the operators whenever a power system is in distress due to overload. Results are presented for three standard test power systems to which the new algorithm has been applied.