Lord Consulting

• Power Industry heavily dependent on SF6
• stewardship of SF6 needs urgent review…
  • aging GIE plant
  • greater awareness of role of gas quality in GIE life/reliability
  • …driving a trend toward improved, formalised, and more regular SF6 testing regimes
• SF6 a very significant greenhouse gas
• … and traditional gas managment practices have been lax

This paper describes the development and deployment of new portable on-line partial discharge (PD) monitoring devices for the condition monitoring of medium voltage (MV) cables and switchgear. In order to provide a complete MV network monitoring solution, devices for monitoring of PD at both primary and secondary substations are necessary. The authors describe the technologies and methodologies which have been developed to enable complete network monitoring to be achieved in both small and largeMV distribution networks.

With such technologies in place it is possible for the PD activity on a particular item of plant to be measured over a short periods of time (days/weeks/months) with advanced diagnosis and PD location carried out as a follow up, if and when required. The distributed monitoring devices which are used at secondary substations can assist in testing longer circuits (>1.5km in length) which cannot be solely monitored at primary substations due to the effects of PD signal attenuation on the cables. Precedence-based data capture with multiple PD sensors has also been applied for use at secondary substations which is of particular use in determining which circuit the PD is on and which direction the PD activity is coming from.

A Practical Technique FOR Battery Condition Assessment and Capacity Monitoring.

ABSTRACT:

The management of the condition assessment of standby lead acid battery systems using impedance methods is now a highly regarded and mature technology delivering an accepted compliment to load discharge methods. Offering the significant attributes of being a non-invasive diagnostic method implemented at modest per-cell costs to in-service battery systems, impedance testing may be applied both to absolute or trended ( CBM ) condition assessment philosophies. Given the often sudden nature of battery failure mechanisms, the success of failure prediction is proportional to sampling intervals. Studies have expanded the scope of impedance technology to the determination of deterioration in battery capacity.

Introduction to High Voltage Partial Discharge (HVPD) Ltd

HVPD Ltd is the new name for IPEC HV who specialise in the field of On-line Partial Discharge (PD) detection and monitoring of in-service mv and hv plant. The HVPD Directors (Dr Lee Renforth and Dr Ross Mackinlay) have, collectively, over 50 years of experience in Partial Discharge testing of mv and hv plant. Over the past decade the focus of this work has been on the application of on-line PD testing of in-service cables and plant with the plant ‘live’. This accumulated knowledge of on-line PD testing and monitoring of mv and hv cables has been used in the preparation of this document.

Instructions on how to get a copy of this paper can be found here

Often just viewed as a form of ‘insurance’, an appropriate on-line monitor can not only provide a timely detection of main tank issues but also provide, arguably, an even more signifi cant contribution in the subsequent management of the event with the transformer remaining energised throughout.

Transformers are vital components in our aging power network infrastructure. They often give little outward warning of impending failure. The failure frequency in older transformers requires a different approach to monitoring, in particular the need to sample more frequently if not continuously. Strategies that worked for the fi rst half of the asset’s life are not necessarily appropriate for the second half. The increasing availability of on-line monitoring systems can assist detecting potentially damaging faults in transformers early enough to take appropriate offsetting action. This paper overviews typical failure mechanisms in large power transformers and their associated auxiliary components and reviews some of the on-line monitoring systems now available.