Transformers are generally considered to be the costliest assets in a power network. The lifetime of transformer is mainly attributable condition its solid insulation, which turn measured and described according degree polymerization (DP) cellulose. Since determination DP index complex time-consuming requires taken out service, utilities prefer indirect non-invasive methods determining based on...

Partial discharge is the commencement of failure of insulation of electrical devices used at high voltage. If such discharge is not detected then fault may increase at the working duration. Basically partial discharge is the cause of failure of insulation in electrical equipment. The insulation of electrical equipment deteriorates due to thermal, mechanical, electrical and environmental stresse...

Partial discharge (PD) events happen inside the power cables and cable terminations with the insulation degradation. The PD detection can effectively supply the information of cable status. According to the electrical and electromagnetic emission of PD activities, high-frequency transformer (HFCT) and ultrahigh-frequency (UHF) methods are employed to detect the PD signals. Besides, a portable P...

Impulse generator is an indispensible high voltage set. It simulates the voltage due to lightning and switching surges and used for testing of insulation of various electrical equipments like transformer, insulators etc.The standard impulse waveform could be used to test the strength of electrical equipments against the lightning.Lightning characteristics and standard impulse wave form are rela...

Optical detection is reliable in intrinsically characterizing partial discharges (PDs). Because of the great volume and high-level power supply of the optical devices that can satisfy the requirements in photosensitivity, optical PD detection can merely be used in laboratory studies. To promote the practical application of the optical approach in an actual power apparatus, a silicon photomultip...

Signal injection method (SIM) is widely applied to the insulation parameters’ measurement in distribution network for its convenience and safety. It can be divided into two kinds of patterns: injecting a specific frequency signal or several frequencies’ groups, and scanning frequency in a scheduled frequency scope. In order to avoid the disadvantages in related researches, improved signal injec...

The insulation condition monitoring of a power transformer has an important role for insulating materials which are subjected to extensive breakdown stress. In this study, a test setup has been constructed in order to simulate real world breakdown characteristics of transformerboards which are widely used as the insulating material. During the service life transformerboards may display undesire...