Impulse voltage distribution on disk winding: Calculation of disk series capacitance using analytical method

Nonlinear voltage distribution along the transformer winding during a lightning overvoltage can cause severe electric stress specially to the area of the winding close to the high voltage terminals. For high voltage transformers different methods such as interleaved winding, electrostatic shield wires, and wound-in shield wires are implemented...

Cable Capacity Enhancement by Utilizing Trapezoidal Voltage Waveform

To avoid installation of expensive new underground cable connections in locations where peak load exceeds existing cable capacity, it is advantageous to transfer more power through a cable than its nominal power capacity, without endangering its reliability. Dynamic current rating of cables is a typical approach that is used to exceed the...

Future Challenges for Cable Accessories in Medium Voltage Networks

In recent years, the architecture of the power system has been the subject of a major change. The commonly known structure with centralized generation and one directional power flow, gives gradually the place to the new concept of the power network where both the energy generators and consumers are distributed. Particularly, the continuously...

Frequency-independent breakdown strength of dielectric elastomers under AC stress

Soft insulators are the main component used in dielectric elastomer actuators (DEAs). It follows that dielectric properties like permittivity and dielectric strength of the insulator can strongly influence the maximum dynamic actuation performance of DEA devices. We observed an increasing breakdown voltage with increasing driving AC voltage...

Multi-electrode lens optimization using genetic algorithms

In electrostatic charged particle lens design, optimization of a multi-electrode lens with many free optimization parameters is still quite a challenge. A fully automated optimization routine is not yet available, mainly because the lens potential calculations are often done with very time-consuming methods that require meshing of the lens...

Mechanical stretch influence on lifetime of dielectric elastomer films

Film pre-stretching is a widely adopted solution to improve dielectric strength of the DEA systems. However, to date, long term reliability of this solution has not been investigated. In this work it is explored how the dielectric elastomer lifetime is affected by film pre-stretching. The dielectric loss of soft polydimethylsiloxane (PDMS) films...

Motion magnification techniques for aeolian vibration measurements

Aeolian vibration of power line conductors is a known phenomenon but damping it properly can still present a challenge in some cases. What sets Norway apart from most other countries is a large number of long spans, some of them having very high every day tension. Eight out of the ten longest spans in the world are in Norway and the everyday...

Insulation Reliability of Superconductive Cables

High current capability, good integration in urban area and zero external magnetic field are advantages of HTS cables that make them interesting for implementation in the Netherlands. So far experience with HTS cable projects is good, but still limited. Yet there is a need for a proper testing practice. Due to limited operational experience,...