Underground Base Metals Mine and Surface Facilities Australia
Introduction
Engagement for a power provision study with four sub-studies including loadflow, fault level analysis, protection coordination and arc flash for an underground mine and surface facilities, with simulated scenarios run in SKM Power Tools software.
Mandate
Palaris had been providing statutory electrical engineering support to the Client’s underground base metals mining operation when it was engaged to further deliver a power provision study for one of the underground mines and related surface facilities.
The study comprised four sub-studies:
Loadflow study to determine the dynamic electrical loads throughout the mine under various operating conditions.
Fault level analysis study for computation of the three phase, line to line, line to line to ground and single line to ground fault levels at numerous locations around the mine. To assist in helping to determine the suitability of the switchgear installed is fit for purpose and will aid in protection setting development.
Protection coordination study to ensure that the protective device settings are ALARP and sufficient protection grading is achieved.
Arc flash study to analyse the prospective incident energy levels and arc flash boundaries at numerous installations throughout the mine. This will assist site in determining suitable controls for the respective installations.
Approach
Prior to conducting the power studies a series initial analysis and data collection was undertaken.
This comprised initial completion of a desktop analysis of the current models on file and compiled to suit the current mine’s high voltage single line diagram.
Secondly was data block report development as a tool which could be used onsite to verify that the current information on file was correct and identify areas with either missing or incorrect information.
Next Palaris undertook a site visit to gather all the missing information required to modify and enter missing information into the PowerTools (PTW) model.
Finally the studies themselves were completed with a number of simulations run in PTW for each.
Outcome
From the studies three key outcomes were: identification of a loadflow bottleneck in the underground cabling used, opportunities for protection optimisation to reduce unwanted trips and thus downtime, and proposed changes to reduce arc flash potential suggested.
Palaris has since been engaged further for a electrical risk assessment for the operation.