Continuous Positive Space Charge in Silicone Rubber Insulation

In the case of silicone rubber, the space charge measurement is confronted with difficulty due to the elasticity of the material. Moreover, it has been found that the space charge presents critical behaviors with respect to the hard material. This work focuses on the positive space charge characteristics of silicone rubber, and try to further understand the positive charge dynamics in silicone rubber material. The space charge profiles were measured by a typical pulsed electro-acoustic (PEA) system under room temperature. A critical positive charge injection and positive charge packet occur in the sample with a low injection field. Negative charge injection also occurs, and the negative homo charge accumulation locates near the electrode. The positive charge packet indicated an enhancement by the field and migrated faster under the high field. Non-uniform distribution of traps and deep hole traps contribute to the positive space charge dynamics in silicone rubber sample.