Relation between electroluminescence and degradation in XLPE

In order to clarify the relationship between electro luminescence (EL) and degradation in crosslinked polyethylene (XLPE), the EL measurement was carr ied out using three kinds of samples, block samples with two different elec trode systems, and him samples. The spectral measurements revealed that the vv component of EL is below the detectable level of similar to 0.1 c/s (co unt per second), in contrast to partial discharge (PD) light from microvoid s or the tiny electrical tree which includes a uv component of greater than or similar to2 c/s. Secondly aging tests using XLPE block samples with nee dle-plane electrodes revealed that electrical degradation can take place ev en when the applied voltage is below the EL detection voltage. The above ex perimental results suggest that EL is not the origin of electrical degradat ion, i.e, photodegradation by the uv component of EL is not the dominant me chanism of electrical degradation.