When it comes to power distribution networks at mine sites, some of the key challenges and risks that organisations face are safety in operation, reliability and sustainability of equipment, says Warren Utteridge, who has over 35 years experience in the electrification field, and is the Sales Manager for Mining – Electrification at ABB Australia.
“Safety is the priority for all of us in this sector,” he stresses. “In medium voltage substation environments it is important to manage these risks by planning substation layouts, with the correct application of the selected switchgear, and ensuring the personnel managing this equipment on site are trained to a certain level of knowledge on switchgear operation and maintenance procedures.”
While the above seems logical, Warren acknowledges that zero harm is still an unrealised target in Australian mining. In September 2022, a process operator in a Northern Territory mine suffered an electric shock when accessing an electrical cabinet. In 2020, the New South Wales resources regulator reported five electric shock incidents in mines that year. These are just a few examples that demonstrate the danger that electrical equipment in mines can pose to personnel.
“Until there are no more injuries, there is room for improvement when it comes to risk controls around switchgear in mines,” he says. “There are solutions that can reduce this risk in the design, including products that are tested to have passive safety features with options to overlay active safety measures, to create safe zones for operation.”
While zero harm is the priority with electrical switchgear in mines, Warren points out that reliability and sustainability are related challenges. This is because understanding the equipment condition can be a predictor to operational reliability and power availability at a mine, which determines when maintenance should be performed.
“Whilst the focus there would be on maximising mine production output, condition monitoring is still very much connected to safety, as it will help determine when and how long personnel will be performing maintenance on the switchgear, prior to the inconvenience of an unplanned shutdown due to unmonitored failures,” he explains. “Remote operation and condition monitoring also take people out of harm’s way.”
As a company with 130 years of electrification experience in mining, ABB can support miners in addressing these challenges, says Warren.
“ABB medium voltage switchgear and compact secondary kiosk substation solutions are designed to protect operators and safely manage overpressure, which can be caused by events such as internal arc faults,” he explains. “Although very rare, such events can be destructive and can cause serious bodily harm. Interrupting the fault as quickly as possible is the key to achieving higher levels of safety, whilst limiting potential equipment damage, resulting in reduced downtime after such faults.”
He mentions the ABB REA arc detection units, which can send a trip signal to circuit breakers in less than 2.5 milliseconds, and the ABB TVOC-2 arc guard system, which sends an electrical signal within 1 millisecond to a nearby breaker after detecting the light of an arc. Additionally, he says there is the option of protection relays within ABB’s Relion series which incorporate light detection inputs and issue a trip signal in 7 to 10 milliseconds.
“These detection speeds are faster than conventional protection relay output times,” he says. “Added to the circuit breaker opening times, these technologies speed-up interruption of current considerably, limiting damage and downtime, whilst importantly increasing operator safety.”
Warren says collaboration between suppliers, mining customers and their key stakeholders is key to support correct product selection and application for critical plant applications.
“Ultimately, the best outcome is achieved by using type-tested products correctly installed to maintain, the safety of the type test certification, with validation from design to operation,” he elaborates. “The second step ABB promote is familiarisation training around the operation and use of our products.”
According to Warren, training is essential for safety and reliability. This can be challenging for mining companies with an increase in staff turnover and contracted fly in, fly out workers.
“One of the difficulties that mining organisations face is maintaining a level of experienced and trained personnel on site,” he says. “As a global manufacturer and local market supplier, we take this responsibility seriously and can support miners with localised service support and training to ensure appropriate skill levels are upheld on site.”
In addition to training, Warren says there are also benefits with digitalisation, such as the remote monitoring of switchgear. ABB ZS1 air insulated switchgear can be fitted with a condition monitoring system SWICOM which is a solution that converts real time data from sensors into diagnostic information.
“To maximise medium voltage switchgear reliability, the ABB SWICOM condition monitoring system digitally communicates switchboard health and trending on compartment temperatures, partial discharge and – with the use of ABB Relion protection relays – circuit breaker condition in real time,” he explains. “SWICOM provides data visualisation on local or cloud-based systems over IEC 61850 connections.”
By detecting any developing issues early, Warran says mine operators can plan their inspection or maintenance at optimal intervals. “From a reliability point of view, it is preferable to perform planned maintenance tasks that are driven by trending data at optimal times, rather than potentially be faced with a mine shutdown,” he adds. “And from a safety point of view, you’re not putting people in potentially hazardous situations due to an emergency intervention.”
In terms of sustainability, Warren points out that a reduction in the structural footprint of substations is possible when switching to ABB digital switchgear solutions. “This is because ABB’s solutions use current and voltage sensors, rather than conventional instrument transformers, which provides a weight reduction on the switchboard of about 20 per cent,” he says. “Instrument chamber wiring is also reduced using sensors, which equates to less materials being used in the switchgear manufacture and in substation construction.”
Moreover, digital switchgear can further increase safety by combining remote functionality such as remote circuit breaker racking, remote opening and closing of circuit breakers and motorised earth switches. To provide an example of where ABB has delivered a solution with clear safety, sustainability and reliability benefits, Warren references a case of where ABB ZS1 switchgear was supplied to a major Australian mining company.
“In line with safety and sustainability, ABB supplied ZS1 air-insulated switchgear fitted with remote circuit breaker racking, remote open and close of circuit breaker and motorised earth switches – all of which can be operated from a simple remote control console,” he explains. “Operation of the ZS1 Switchgear is error-free due to the electrical, mechanical and digital interlocking. And the remote operation console is positioned safely outside of the high voltage substation room.”
The ABB ZS1 medium switchgear was supplied within a modular switch room and fitted with an overpressure relief duct that was vented outside of the substation. This offers maximum operator protection whilst maintaining structural integrity of the substation building in the rare case that an internal arc fault developed.
Warren closes by saying that ABB partners with miners to empower them in achieving their zero harm and sustainabilty goals. “ABB engages in whole of mine electrification process control, and motion control, and supplies a full suite of electrification products from low voltage to medium voltage distribution levels. Consider collaborating with ABB to improve the safety and reliability of your mine site and by reducing project integration risks through introducing the ABB product portfolio, with connected digital solutions.”
For more information on the medium voltage solutions that ABB has to offer, please click here.
This feature appeared in the on the MiningMonthly.com website in September, 2023.
