Gas–solid interface charge characterisation techniques for HVDC GIS/GIL insulators

Design and selection criteria for HVDC overhead transmission lines insulators

Effects of Deposited Charge on Impulse Test Techniques for Polymer Insulators

The application of lightning impulses to polymer insulation, including composite insulators, can result in the deposition and retention of significant quantities of charge on the surfaces. This is very evident after withstand impulses near U50. The presence of retained charge means that the polymer test object has a memory of preceding impulses and this compromises the main requirement for dete...

Emerging superconductivity hidden beneath charge-transfer insulators

In many of today's most interesting materials, strong interactions prevail upon the magnetic moments, the electrons, and the crystal lattice, forming strong links between these different aspects of the system. Particularly, in two-dimensional cuprates, where copper is either five- or six-fold coordinated, superconductivity is commonly induced by chemical doping which is deemed to be mandatory b...

Fault Current Characterisation in VSC-based HVDC Systems

The DC-side line faults in high-voltage direct-current (HVDC) systems utilising voltage-source converters (VSCs) are a major concern for multi-terminal HVDC systems in which complete isolation of the faulted system is not a viable option. A number of challenges are posed by both pole-to-pole and pole-to-ground faults including the presence of very fast and high amplitude discharge current from ...

Understanding of tuning techniques of converter controllers for VSC-HVDC

A mathematical model of a voltage source converter is presented in the synchronous reference frame for investigating VSC-HVDC for transferring wind power through a long distance. This model is used to analyze voltage and current control loops for the VSC and study their dynamics. Vector control is used for decoupled control of active and reactive power and the transfer functions are derived for...