Electromagnetic time reversal for on-line partialdischarge location in transmission and distribution networks

Overview

Energy is crucial for the developing World and must be provided when needed to avoid serious impact on society.

Among all energy forms, electricity has an increasingly central role.

Electricity security is the power system’s capability to withstand disturbances or contingencies with an acceptable service disruption and represents a crucial concern forpolicy decision-making at all levels.

Usually, service disruption is due to cables insulation damage, often caused by, or accompanied by, a partial discharge (PD) event that is a localized electrical discharge that partially bridges the insulation between conductors. Since PD is one of the best early warning indicators of insulation damage, the on-line PD location is the most suitable method of monitoring network integrity and a desirable network protection method to guarantee electricity security.

The project’s main objective is to develop a new method for online PD location based on the innovative electromagnetic time reversal
(EMTR) theoy.

Effects of Partial Discharge

✓ Cable premature failure within 3 years of operation
✓ Localised heating/moisture into the cable
✓ Interruption of power supply
✓ Reduction of power quality and customer satisfaction
✓ Reduction of Electricity Security of Power Networks.

On-Line Partial Discharge Location in
Power Networks

On-line PD location is a desired feature in modern protection schemes’ power networks to guarantee:

  • a fault preventive action, improving reliability
  • a continuous monitoring condition for grid integrity
  • an increase of equipment lifetime and network resilience
  • a reduction of overall operating costs increasing plant productivity
  • a reduction of outage duration of supply,
    improving power quality, customer satisfaction and life quality.

  • Design of EMTR Method to Locat Partial
    Discharge on Power Networks

  • EMTR methods, in source-location identification, take advantage of the time reversibility of Maxwell’s equations and the spatial correlation property of the time-reversal theory to refocus the time reversed back-propagated electromagnetic waves into the original
    disturbance location: when the electromagnetic wave is time reversed and back injected into the original system, it refocuses back to the location of its source.

  • The new method to on-line locate PD source based on EMTR theory and using the Transmission Line Matrix (TLM) method
    to model PD signal propagation, under development at DMU.