This paper focuses on improving the solution techniques
for the AC　problem of active power dispatch by
using the DC approximation within the algorithm.
Our approach brings two benefits compared with benchmark
algorithms: it speeds up the solution of an iterative AC
algorithm thanks to a more efficient identification of
binding contingencies and allows improving the objective by an
appropriate choice of a limited number of corrective actions for
each contingency. The proposed approach is illustrated on five test
systems.