Investigation on charging and polarization effects at dielectric interfaces in laminated HVDC insulation

Conduction current measurements in conjunction with space charge measurements provide deeper insight into the charging behavior of an insulation than one method alone. In this paper results from both test methods obtained for materials used in the construction of solid/liquid laminates are discussed. Special attention is given the comparison between measurable and theoretical values of the amount of charge that accumulates at the dielectric interface as well as the time constants for its build up and decay. Analyzing these differences, additional information is gained regarding the space charge and polarization in such laminated structures. Likewise, space charge distributions in laminates are more reliable assessed this way.