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The world is well underway in transitioning over to electrification to power future transport systems, this is driven by the requirement to reduce carbon emissions associated with the use of fossil fuels and the impact on the environment, stricter international legislation is also helping to accelerate this transition. EV registrations have now overtaken new diesel vehicle sales in the UK, with this trend set to continue as we approach the ban on new petrol and diesel vehicle sales coming into force in 2030.

One key aspect of Electric Vehicles (EVs) is they are much less complicated than traditional internal combustion powertrains, this is primarily due to the removal of the thousands of mechanical components that make up an internal combustion engine and its supporting mechanical subsystems. However, whilst they are mechanically simpler, they now present a new set of engineering challenges. In particular, they require more sophisticated monitoring of key functions and parameters to achieve the high performance and efficiency needed to maintain safe and stable operation. At the same time, the voltages used in EV powertrain architectures are increasing from 400V to 800V in a bid to enhance efficiency and shorten charging times, thus making vehicle and user safety an even more critical requirement. These systems will require reliable, compact, lightweight and robust connectors that can handle the signals and power associated with electric powertrains.

These engineering challenges are not unique to eMobility powertrains, there are many other applications which they share common attributes with, for example automated guided vehicles (AGV), robotic systems and material handling equipment used in warehouse environments. These applications also use electric motors and powertrains often along with large battery packs, all of which require detailed monitoring, control, safety and power electronic systems. To a lesser degree, similar can be said for the charging infrastructure needed to keep this equipment running efficiently.

Interconnect selection

eMobility and the charging infrastructure equipment will require interconnect components that can handle power as well as high speed data signals used in the battery management system (BMS), they also need to be highly durable to cope with the harsh application environment which will include shock, vibration and the requirement to operate over wide temperature ranges. Additionally, due to the high level of integration needed in eMobility powertrain systems to achieve the required compact dimensions, the connectors will often be fitted in positions that make repair and maintenance work difficult and costly. Therefore, any interconnect components used must be highly durable to ensure long-term reliability at system and component level, specifying suitable connectors from a reputable brand such as Harwin is critical.

Several key criteria must be considered when specifying connectors for eMobility and charging infrastructure applications:

• High Speed - The safety-critical nature of EV monitoring activity means that data transfer must be carried out at high speed, with low latency and assured reliability. Therefore, connectors that support the data rates defined by the latest in-vehicle networking protocols should be selected. Superior signal integrity also needs to be attained, even with potential sources of electromagnetic interference (EMI) nearby.
• Multi-functionality – The use of connectors capable of delivering power and data is preferable, this allows further space-saving. Reducing the amount of board real estate utilised also means less wiring is needed.
• Compactness - Another aspect to be considered is the space-constrained environment. Specified connectors need to be compact, while still featuring a high number of contacts, and be rugged enough to cope with shocks, vibrations, and extreme temperatures.
• Reliability– Due to the application environment, the connectors need to be robust and reliable to cope with shock, vibration forces, and extreme temperature fluctuations. These can each have an impact on the equipment’s reliability and lifespan if the incorrect connector components are specified.
• Cost - As the expense of EVs can often be a concern for prospective vehicle buyers, keeping the overall bill-of-materials costs down is a high priority for automotive manufacturers. Therefore, the connectors must have all the described features and be positioned at acceptable price points. However, the “cost” of the connector must not be confused with price, cost of ownership should always be the key consideration, this encompasses reliability, convenience of use and functionality of the connectorsystem.

Harwin have several families of connectors which can be used effectively in eMobility powertrain and charger infrastructure applications:

Kona

The Kona 8.50MM pitch high reliability connectors expand the Harwin portfolio into new levels of current – 60A per contact.

At the heart of the Kona connector is a compact yet powerful 6-fingered male Beryllium Copper contact, turned in Harwin’s state-of-the art HQ facility. Capable of 60A per contact, with minimum PCB footprint and height above board the Kona family maintains the high quality standard set by other High-Reliability connectors in the Harwin range. Capable of power connections for demanding applications on land, sea and air.

Designed to withstand testing environments and conditions the connectors are currently offered in 2, 3 or 4 single row configuration, for vertical cable-to-board or cable-to-cable. The connectors feature excellent vibration and shock resistance.

Archer Kontrol

The Harwin Archer Kontrol family is a board-to-board connector system widely used in various EV models for powertrain monitoring and diagnostic tasks.

The connectors have a 1.27mm pitch and compact form factor, and they are available in vertical or horizontal orientation options to minimise space used in the system design. Stacking heights from 8mm to 20mm are available, giving system designers greater flexibility. The connectors utilise phosphor bronze contacts with a gold/tin finish offering prolonged durability and housings are constructed using robust high temperature plastic rated to UL94V-0. Contacts are also fully shrouded and polarized helping with blind mating or angled connection assembly and are designed to handle lateral and twisting forces that can be encountered during vibration and manual operation.

The connectors meet automotive applications’ Ethernet network infrastructure standards, with 3Gbps data rates supported. They have an operating temperature range from -55°C to +125°C, and high shock and vibration resistance of 20G for vibration, and 50G for shocks.

Ready-made cable assemblies in 150mm and 300mm (6″ and 12″) lengths – female-to-female are also available with latches for additional strain relief.

Gecko-MT connectors

The 1.25mm-pitch Gecko-MT series from Harwin is the most compact and lightweight combined power/data connectors in its class. These connectors are highly optimised for use in eMobility and industrial automation systems, they are available in board-to-board, cable-to-board, and cable-to-cable options.

The Gecko-MT connectors incorporate an array of 8x 2A-rated contacts for data transmission, accompanied by power contacts (either 2 or 4) capable of delivering 10A currents. They feature a proprietary four-finger contact design which assures interconnect integrity – even when exposed to heavy shocks (up to 50G) or continuous vibrations (up to 20G).

The data and power contacts the Gecko-MT uses are manufactured from Beryllium-Copper alloy, giving enhanced electrical performance alongside long-term durability. This allows to connectors to offer 1000 mating cycle durability. The Stainless-Steel jackscrews strengthen mating retention, and parts have an operational temperature range of -65°C to +150°C.

Click below to see an introduction of the benefits of mixing power and signal connections in one connector

Datamate Mix-Tek connectors

For applications that have greater power carrying requirements, Harwin offers the Datamate Mix-Tek series of connectors. These can be specified in configurations with single row power or 6GHz coax contacts alongside double row signal contacts.

The same 4-finger contact arrangement with Beryllium-Copper construction has been employed to mitigate the effects of shock and vibration. The Datamate Mix-Tek signal contacts can handle 3A currents, while different current levels can be supported by the power contacts – going from 5A up to 40A. 20AWG wiring can be used for 5A system designs, but for higher current levels (20A or above) 12AWG wiring should be used.

The Datamate Mix-Tek connectors can handle temperatures from -55°C to +125°C and are specified for 500 mating cycles. For additional security and robustness additional Jackscrews are optional, with both standard and reverse-fixing versions being provided. Fast mating 101Lok locking mechanisms can also be specified.

EMI Shielding Cans and Clips

As well as having compact and robust interconnects, eMobility and charging equipment must also be protected from electromagnetic interference (EMI) – otherwise, the quality and integrity of the data signals will be compromised.

For this reason, Harwin supplies Nickel-Silver shielding cans in various shapes and sizes. Attached via surface-mount clips, these are easy to fit and replace, with configurations adaptable to new design layouts. Additionally, through the shield can kits Harwin have also made available, developers are now able to quickly create custom shields for use in prototyping.

Click below to see how easy the EMI Shielding Cans are to remove and replace

Conclusion

EV powertrains rely on high performance power and data signalling capabilities. The real-time communications now needed between all the different powertrain subsystems, from the battery packs to the onboard and offboard chargers and DC/DC converters, result in higher efficiency and greater overall safety. Specifying the right interconnect solution is critical to allowing manufacturers to gain a competitive advantage, while safeguarding their brand reputation.

Anglia are offering customers FREE samples of the Kona, Archer Kontrol, Gecko-MT, Datamate Mix-Tek and EMI Shielding Can products from Harwin, please fill in the form below to register your interest now.