Taking charge

Online Editor

Alain Schierenbeck showcases a novel charging solution for electrified mines.

The shift toward electrification within the mining industry appears to be unstoppable at this point. Encountering the harsh realities of cost, environmental harm, and work safety, mining is forced to take bold steps towards more sustainable practices. In the future, we can expect electrified mines to become the norm. Charging solutions for high-performance commercial vehicles and mobile machinery will be the key players in powering this shift toward sustainable mining practices.

Revolutionising the mining industry with electrification heavily relies on the charging capacity of mine vehicles. These high-tech electric-powered vehicles present unique hurdles, requiring seamless integration of charging cycles into day-to-day operations. The market is teeming with various charging solutions for electric mine vehicles: battery swap, stationary charging, opportunity charging, or a customised blend of all. Selecting the perfect solution requires a thorough assessment of the project to determine its needs, as each charging option comes with its own set of benefits and limitations.

Battery swapping

Battery swapping technology is a promising solution to cut down charging times. However, it faces some critical hurdles. One of them is that batteries are not standardised, leading to a plethora of variations in size, shape, and location within the truck. Moreover, battery swapping requires a station that comes at a steep cost.

Stationary charging systems

The stationary charging system requires vehicles to be taken out of circulation for charging, reducing overall efficiency and leading to increased costs. The lengthy process of connecting and disconnecting from a stationary charging station also translates to longer vehicle downtime, further impacting operations. This, in turn, compels mines to widen their fleets to prevent mining disruptions, adding to the costs associated with initial investment, maintenance, and storage space. Additionally, stationary charging stations may be inflexible and may not conform to the regular procedural demands of mining operations, thus requiring a charging station that can be easily relocated. This mobility enables movement to the optimal location, avoiding any unnecessary travel for charging that may arise from deepening mines or opening new shafts, ultimately leading to cost savings and improved efficiency.

Stationary charging does present challenges to mine electrification projects that are not present in battery-changing processes. However, automated, fast charging can overcome these difficulties and ultimately deliver improved performance over the battery-changing alternative.

Fast charging

Fast charging technology is the key to unlocking the potential of electrification in mining: it can reduce or even remove the problems associated with taking vehicles out of the cycle for charging. This is because charging can take place whenever the vehicle is not moving: during breaks, between shifts, and even during operation while loading and unloading or queueing to load and unload. This dynamic charging method is referred to as opportunity charging.

Opportunity charging must be carefully planned so that the battery cycle aligns with the mining operation cycle. A well-planned opportunity charging cycle can keep electric vehicle batteries topped up to acceptable levels in short bursts of charging whenever the vehicle is stationary. This kind of charging could achieve continuous operation for an electric vehicle fleet during shifts. It can also enable heavy-duty electric vehicles to operate with smaller batteries, as they are continually recharged throughout the shift. A smaller battery requirement enables a larger overall payload for haul trucks, improving productivity in the electrified mine. Not only this, but opportunity charging can also eliminate the need for extra vehicles and the costs associated with that need.

Robustness and safety matters

Due to the harsh environmental conditions such as dust, humidity, and heat, the various charging methods utilised must possess a ruggedness that can endure these circumstances and ensure steady operation of the electrified mine. Safety is a significant factor to consider along with the topic of robustness when implementing charging solutions. This involves ensuring the safety of workers on-site and during the charging of electric trucks. Automatic charging solutions can help enhance safety measures for workers in such environments.

A new approach

With the innovative QCC for high-performance charging system, Stäubli offers a solution that provides the high charging performance and maximum reliability and safety for high-performance commercial vehicles and mobile machinery. The advantages of the system overcome the challenges for stationary charging systems outlined above. The robust design of this solution ensures high reliability and durability, with low maintenance requirements. More importantly, the solution also prioritises safety for workers and battery charging cycles. Stäubli is currently working on upgrading its standard QCC range with even more power, enabling the system to charge up to 6MW. This will make even faster charging cycles possible.

The high charge capacity and full automation make the QCC system perfect for opportunity charging, enabling continuous operation of the mining fleet meeting the 7,000 hours
of annual uptime needed for haul trucks. The specific design of the QCC allows high protection of the contact parts at all stages (mated, unmated, and during mating), which guarantees high reliability under harsh conditions. This ensures that there are fewer failures, providing a more efficient and reliable solution.

The charger is designed for high numbers of mating cycles, so it represents an excellent long-term investment for electrified mines. Its small footprint makes it easy to retrofit the QCC system into existing mines, and installation does not require major construction.

Alain Schierenbeckis with Stäubli Electrical Connectors.