Stäubli has sponsored this post.
Electric vehicles (EV) seem to be taking over the world, not only on highways with consumer vehicles but also in industrial and commercial uses. One of the most significant challenges to sustained EV adoption is how to make them more efficient.
But there’s another factor that could have an equally profound impact on EV market growth: the availability of powerful and efficient chargers. And the key to maximizing the effectiveness of chargers could be the connectors that link the battery to the power source.
In fact, a disproportionate number of challenges—and costs—arise from the interface between various EV systems, such as the powertrain, the battery and the charging station.
Those interfaces—the connectors—play a significant role, and not only for the EV that may be charging in your garage right now. They are also critical components of commercial EVs that operate in sectors such as industrial facilities, renewable energy, power transmission and distribution, rail, ports, welding automation (including the robots that actually weld EVs), testing and measurement as well as E-Mobility.
The connector is assumed to be a mature technology—but in fact, it’s not. Engineers need to tackle challenges including performance, durability, production, qualification and regulatory requirements and, of course, cost.
A company may consider solving its connector challenges with in-house solutions. But does your in-house design team have the resources it needs to create solutions, working with multiple combinations of polymers and metals? And what is the opportunity cost that comes with going in-house? For assembly lines creating products that have connectors, can the in-house team deliver a solution with production-ready parts for line start while coordinating a supply chain to deliver enough components? There is also the human factor to consider: can assembly line personnel reliably install connector after connector accurately and safely, without damaging a potentially sensitive component?
If an in-house solution doesn’t meet a company’s needs, it can bring in an outside vendor that specializes in high-current connector design, such as Stäubli —and the earlier such a consultant is brought into the process, the more likely your connectors will be the least of your worries when the assembly line starts producing the final product.
When designing a connector, it’s more than just the ampacity, which is the maximum amount of current it can carry continuously without exceeding its temperature rating. Connectors also have to be designed to withstand worst-case scenarios when it comes to peak and continuous current, heat rise and management, fluctuations in power cycles, ambient conditions (ranging from moisture in humid or winter environments, corrosive salt in coastal regions, as well as sand and dirt), and safety and human factors.
Heat rise can be monitored and controlled by software using current sensors or embedded sensors. However, this requires that the engineer balance competing complexities; For example, added complexity in the charging algorithm versus added cost of high-temperature materials in the connector itself.
These connectors also have to factor in a new opportunity and challenge: automation. Current battery technology limitations mean that vehicles need to charge frequently, and robotic connections are gathering more interest. These machines could connect to a charger while a vehicle stops for loading and unloading. It also opens possibilities for mobile charging, where a robot comes to the vehicle to charge it. Connectors in these scenarios could require different design elements and standards than the ones currently on the market.
These are just some of the puzzles that a specialist such as Stäubli can provide expertise on—and components—in order to create solutions.
For example, for demanding operations related to vehicle powertrain, Stäubli offers its PerforMore electric drive train connector that is purpose-built to enable stable high-current transmission between batteries, inverters and high-voltage charging inlets.
“This connector is the highest power rated connector available on the market,” said David Rababy, head of sales for E-Mobility in North America for Stäubli Electrical Connectors. PerforMore is rated to 600 amps at 40 degrees C and features a two-stage lock for safety—and does so in a compact design while maintaining the clearances and distances required for high operating voltages.
It also displays excellent vibration resistance thanks to Stäubli’s Multilam connector technology. This connector is comprised of a series of louvers and contact points that can concentrate the current and minimize contact resistance, resulting in a stable and consistent current with minimal power loss.
As a result, the PerforMore is well suited for use on a variety of DC interfaces that have high technical requirements, such as batteries, and applications that involve lots of vibrations or where the connector is in a harsh environment.
For applications that require some customization, Stäubli also offers the CombiTac modular connector, which can be easily adapted to meet the requirements of each application. It can be configured to connect electrical power and electric signal, as well as fluids such as coolants, fiberoptics, thermocouples and Ethernet lines. They can also be configured to terminate in different housings.
“These types of connectors are rated for about ten times the mating cycles that a standard charge plug is rated to,” said Rababy. “They are rugged and robust, and can also be configured to whatever the requirements are.”
Stäubli also offers the option to configure the CombiTac online—from planning to inquiries to commissioning to after-sale communication. This enables users without much prior knowledge to create their very own CombiTac solution and tailor it to their individual needs.
This connector is ideal for applications that need unique charging solutions such as automated guided vehicles (AGV) or robotics systems. Most applications that use the CombiTac are industrial, such as mining, utility power, construction and agriculture. They can also be found e-mobility for battery swapping for commercial vehicles. In addition, this component is well suited for battery pack testing; it can be plugged and unplugged hundreds of thousands of times for testing.
With regard to automated operations, Stäubli offers its Quick Charge Connector (QCC), a connection device purpose-built for automation that can be integrated into a variety of vehicles and applications. Despite its compact size, it allows for high power transfer; in fact, the charge it can handle is an order of magnitude higher than the level 1, 2 and 3 chargers currently on the market. The QCC is fully insulated against touch and water contamination, enabling use in public areas and exposure to elements. This connector can be found in operations from ferries to ports to heavy duty mining and commercial equipment, and is not meant for use in consumer vehicles.
“The QCC is best suited for rugged, high-power and/or mission-critical applications where downtime and unscheduled maintenance are costly, where it makes sense to remove the end user from the charging connection process, and where high-power is needed to optimize OPEX” said Rababy.
In fact, the QCC has been incorporated into high power chargers for a fleet of 33 electric tractors at the Port of Long Beach, California. The QCC system features an enclosed pin-and-socket design that is touch-protected on both sides of the connector and is able to quickly and easily correct for misalignment when the tractors attempt to connect with the chargers. The system enables automatic connection between the chargers and the charging ports that have been retrofitted to each vehicle.
As mentioned above, connectors are still an evolving technology. A critical challenge in the connector industry—particularly in the age of Industry 4.0—is scaling up through standardization across different systems that use different technologies. Europe, Asia and North America all follow different industry standards; a cross-jurisdictional standard would enable interoperability over time and would help companies avoid having equipment that can’t be used with different or newer OEM products.
Stäubli is leading a working group focused on developing the Megawatt Charging System (MCS), a new charging standard being championed by the CharIn E-Mobility stakeholder association. The MCS leverages the QCC system to create a new solution for charging electric heavy-duty vehicles efficiently. It would provide up to four megawatts of charging power and is expected in 2024.
For companies operating in the fast-growing and quickly evolving EV sector, finding the right connector for the right operation is an essential decision to be made. Fortunately, these solutions are in reach—whether it’s an in-house solution or a product brought in via a specialist company such as Stäubli.