The secondary voltage control determines control device actions based on reference voltage values set at certain load buses denominated pilot buses. A key factor for the appropriate functioning of secondary voltage control schemes is the selection of the pilot buses. This paper addresses this problem taking into account system‐wide information, and different operating conditions regarding different load levels and different network topologies. The proposed approach improves previous approaches in two respects: the level of modelling detail and the computational efficiency. Two case studies based respectively on the IEEE 118‐bus system and the New England 39‐bus system are provided.