Condition monitoring and diagnostics [Editorial]

This special issue of the IEEE Transactions on Dielectrics and Electrical Insulation (TDEI) is devoted to Condition Monitoring and Diagnostics (CMD) of high voltage insulation systems. Our intension was to pinpoint actual trends in this area of research and engineering. Especially the diagnostics of insulation systems of power equipment becomes particularly important, driven by multi-stress operational conditions and the strive for higher transmission capacity. Also the increasing requirements with respect to safety and reliability in electric power and industrial networks as well as their environmental compatibility set new and special demands.