Application of Return Voltage Measurement for Space Charge Detection and Measurement in LDPE

The phenomenon of return voltage build-up in dielectric materials has been explained from the concept of space charge accumulation. Return voltage build-up was observed in thin low density polyethylene samples after they were charged and discharged for specific intervals. A simple model based on the migration of space charges due to the internal electric field inside the charged sample was presented to explain the build-up of return voltage. From experimentally observed results space charge quantities such as charge density and distribution inside the sample were estimated. The proposed technique can be used for space charge mapping and insulation diagnostics in polymeric insulators in industrial laboratory applications.