The oil/paper insulation system in a transformer degrades under various chemical, thermal and electromechanical stresses during its operation. Dielectric response measurements like the Return Voltage Measurement (RVM) and Polarisation and Depolarisation Current (PDC) measurement are currently being used for condition assessment of the insulation. In the current research project, the ageing cond...

The power transformer is a major apparatus in a power system; it is of great importance to detect incipient failures in power transformers as early as possible in order to minimize system outage. In this paper, the modified grey model was applied to predict the oil-dissolved gas trend of power transformers. Then, the future fault of power transformer can directly be identified by the trend anal...

C2H2, C2H4, and C2H6 are important oil-dissolved gases in power transformers. Detection of the composition and content of oil-dissolved gases in transformers is very significant in the diagnosis and assessment of the state of transformer operations. The commonly used oil-gas analysis methods have many disadvantages, so this paper proposes a Ni-doped carbon nanotube (Ni-CNT) gas sensor to effect...

A distributed transformer networks remote monitoring system(DTRMS) is developed and constructed, for monitor and record the parameters like temperature, oil level status, of a distribution transformer. The system consists of a microcontroller based circuit, with solid-state components for handling sensors, power back-up, real time clock and data communication module which based on ZigBee protoc...

Usually, acoustic partial discharge (PD) and vibration measurements take place on the outside tank wall of power transformers. This contribution determines new approaches for acoustic PD measurements within the oil volume of the transformer combined with electromagnetic in-oil measurements. Scope of the work is an acoustic and ultra-high frequency (UHF) detection of PD and additional recording ...

Transformers are one of the more expensive pieces of equipment found in a distribution network. The transformer’s role has not changed over the last decades. With simple construction and at the same time mechanically robust, they offer long term service that on average can reach half a century. Today, with the ongoing trend to supply a growing number of non-linear loads along with the notion of...

Dry-type transformer becomes the preferable choice in many applications due to its construction specific advantages over oil-cooled transformers. However, the inherent low thermal conductivity of dry-type transformers gives the rise to high operating temperatures. The temperature rise of a transformer is an important factor deciding its safe operation and the useful life span. With the increase...

Original scientific paper In electrical power system, variety of solid, liquid and gaseous materials are used for insulation target to protect the incipient failure inside the high voltage power transformers. The insulation is practically ended when the insulation system has become fragile enough to flourish cracks under the electrical and mechanical stresses to which it is subjected. The elect...

The reliability of electrical energy networks depends on the quality and availability of electrical equipment like power transformers. Local failures inside their insulation may lead to catastrophic breakdowns and can cause high outage and penalty costs. Beside the strength and type of a PD, the geometric PD position is of major interest concerning risk evaluation of the flaw. Conventional PD m...

A rotating cylindrical electrode apparatus, which provided cylindrical Couette flow, was used to simulate flow electrification in an electric power transformer. The apparatus had Shell Diala A transformer oil filling the annulus between coaxial cylindrical stainless steel electrodes that were either bare metal, or covered by a thin copper sheet and/or EHV-Weidmann HiVal pressboard insulation. E...