Peter Stepien and Richard Griffiths Senior R&D Engineer's with ResTech will present on the History of Earthing and the Impact on Coal Mining...Read More
ResTech in conjunction with Ampcontrol have been awarded the 2013 National Engineers Australia Innovation Award for our project on the management of VSD earth leakage currents in fault limited networks.
ResTech’s submission covered seven years of research including analysing phenomena, developing simulations, conducting underground research, educating the industry and developing VSDguard a protection regime to monitor VSDs and protect plant and personnel.
The judges described the project as ‘an excellent example of engineering problem solving resulting in the development of a product with international marketing potential. Ampcontrol with ResTech took information that all others saw as "noise" and used it to identify and clear potential hazardous situations in underground mines. The company has applied advanced investigative techniques, modelling and design to produce the product.’
Novecom recently introduced the QuattroSound directional noise monitor, the latest addition to their SentineX range of environmental monitoring solutions.
QuattroSound is the next generation in directional noise monitoring systems, providing unparalleled source detection and analysis. The QuattroSound directional noise monitors enable up to four separate sound sources to be resolved simultaneously, with detailed spectral data available for further characterisation of each source.
ResTech completed a proof of concept realtime data collection and analysis system, implementing algorithms developed by the University of Newcastle School of Electrical Engineering and Computer Science. On successful field trial, Novecom then integrated the data acquisition and signal processing modules from the pilot electronics into the SentineX system, which is now available for commercial sale.
ResTech completed a proof of concept video image processing system to automatically detect failure of a coal wagon to properly empty while over the dump station hopper.
The proof of concept video included an overlayed, synthesised video image of a coal hangup inside a wagon, with the algorithm and decision code to highlight wagons failing to empty. There are approximately 30 different wagon types which significantly complicates conventional detection techniques based on absolute measurements.
ResTech used a heuristic interpretation of video image data (in some ways similar to human recognition) which did not rely on absolute measurements, and so coped well with the various wagon geometries, locomotives and inter-wagon coupling spaceswithout significant complexity or additional non-contact measurement equipment.
Following success of the proof of concept video, ResTech assisted local company Power Control Engineers to complete a commercial implementation. Two video analytic systems based on the ResTech proof of concept are now installed and operational at Port Waratah.
Variable Speed Drives generate high frequency currents that circulate through the cabled and physical earth. With standard earth leakage protection relays and electrical system assessments based only on consideration of faults driven by the supply system (50Hz), protection performance is unlikely to be adequate when variable speed drives are used in mining applications.
Computer modelling has indicated that when powered from a common supply the combined effects of multiple VSDs and EMI filters during fault conditions on the load side of the VSD can excite resonances that cause large circulating currents to flow between the EMI filters. This modelling suggests that currents several times the maximum value of the limitation device can flow at the substation NER.
Therefore, during an earth fault on the output side of an operating VSD high fault currents could also have the effect of generating higher than expected prospective touch potentials at machinery associated with the supply system, not just at the location of the earth fault. There is also an increased risk of sparking between machines, if machines are in close proximity to each other at the time an earth fault occurs on the VSD supplied motor or cable.
ResTech has been investigating this issue for a number of years and are uniquely positioned to help you. We offer:
- Independent assessments of your system to help you understand the effect your earth protection system has on the touch potentials on electrical equipment and ensure your protection system is compliant with the step and touch potentials specified by AS/NZS4871.1:2010. Contact us to find out more.
- A two day seminar exploring the principles and pittfalls associated with earth leakage protection in the high resistance earthed networks common in mining environments. Contact us to find out more.
For more information on this issue refer to Mine Safety Bulletin No: SB11-04 issued 21/12/11
ResTech was commissioned by Aerogenesis Australia to provide electrical engineering expertise to assist with improving efficiencies of their range of small wind turbines.
This included input into the design of the electronic controller and electrical system to allow for the turbine to become commercially viable and operational.
ResTech improved the efficiency of the electrical components of the wind turbine by incorporating a commercially available generator with customised adjustments.
ResTech's support included the design and testing of electrical components such as lightning and surge protection, underground and in-tower cabling, overspeed protection device, excitation system, central controller, user interface and the output filter.
A third continuously running turbine has been commissioned for commercial use after it demonstrated safe and autonomous performance over several months at two earlier sites.
ResTech’s ongoing involvement includes investigating further efficiency improvements, establishing supply chains, streamlining construction and installation processes and exploring connections to electrical grids.
ResTech is a partnership between Ampcontrol and The University of Newcastle and is an Australian provider of R&D to industry in electrical and electronic engineering.
For further information or to discuss how ResTech can provide proof of concept business development for your organisation contact us.