Different vehicle manufacturers are pursuing different routes towards the goal of low or zero emissions, and in doing so will place new demands on connector suppliers.
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BY MARC CUSSET
Several innovative high-power connector solutions have been developed to meet the booming demand for high performance but cost-effective interconnections from virtually all automotive OEMs worldwide, starting with electric vehicle (EV) programs scheduled for launch in 2010/11.
Driven by a host of commercial, environmental, and regulatory factors, the EV and HEV (hybrid electric vehicle) market is set for a period of rapid growth and development. Virtually all the world’s leading automotive manufacturers have a clear product development plan for EVs and/or HEVs, and the number of commercially available models is steadily increasing.
Technologies being pursued range from micro-hybrids (which automatically switch off the conventional engine at standstill and employ a special alternator driven by the battery to restart it) to full electric models. These will run exclusively on a rechargeable/replaceable battery and will be supported by the introduction of thousands of fast-charge service points located in various countries.
Although estimates for the speed with which EVs and HEVs will be adopted by consumers vary widely, even if low-emission models secure only a small share of the current global market for automobiles, a significant demand for low-emission vehicles and, therefore, new connector solutions will be created. In China alone, the government has set a minimum target for a 50% market share for low-emission vehicles by 2015. In addition, Western countries are actively promoting green technologies through a series of governmental and financial incentives, further supporting the trend toward HEVs and EVs.
 FIGURE 1. Terminals on FCI’s RCS-800 automotive connector feature an 8-mm round pin designed for more efficient use of space than an equivalent square terminal. |
Above and beyond the demands of a conventional automotive environment, EV and HEV systems place significant new demands on connectors. Uppermost among these is the high power requirement.
Large lithium-ion (Li-ion) batteries are a key feature of most emerging green vehicles. For connector design, this means handling operating voltages that range from 400 to 600 volts. This represents dramatic increases–at least tenfold–compared to the typical current of conventional cars with 14-volt lead acid batteries.
FCI Motorized Vehicles’ RCS-800 and APEX 280 high-power connector ranges are designed to incorporate a series of features that reflect the unique challenges presented by EV and HEV applications. RCS and APEX connectors are designed to cope with both low- and high-voltage applications, while withstanding any level of operating current, as high as 250 amps or above. Given that both technicians and end users will need to access the engine bay, exceptional levels of failsafe protection must be provided against the threat of electrocution.
Electromagnetic interference is another major issue that needs to be addressed, along with the requirement to keep size, weight, and costs to a minimum.
Terminal, housing design
RCS-800 terminals (Figure 1) feature an 8-mm round pin design that facilitates more efficient use of space compared to an equivalent square terminal. RCS female terminals also provide a high number of contact points and can operate up to 250 amps and above, depending on customer specification.
The housing for high-power interconnections incorporates a 2-step disconnecting device that guarantees the connectors cannot be unplugged while high currents are applied. Two separate user movements are required to ensure enough delay between the power being cut off and connector being free for release. This solution also features an “interlock” device, eliminating the risk of unmating during load.
Additionally, the ErgoMate axial mating system helps achieve a lower profile solution while reducing mating forces. Once connected, a Connector Position Assurance device must be activated to ensure a 100% safe mating. Last but not least, high levels of shielding and sealing are employed to offer best-in-class interconnect solutions for EVs and HEVs, while achieving the automotive industry’s usual, but tough, product and process cost challenges.
As a complement for EVs and HEVs, the APEX 280 (Figure 2) is designed to fulfill the same high-volt- age requirements, with 35-amp electrical performance. The connector addresses applications such as air conditioning, heating, and slow charge plugs. It is fitted with APEX 2.8-mm terminals, and the housing benefits from the same features as the RCS 800–2-step un-mating ErgoMate axial system, interlock device, Connector Position Assurance, and high-performance sealing and shielding features.
Despite a specification and quality standard that might typically be more associated with applications such as aerospace interconnections, these high-power connectors have been delivered at automotive-level pricing. Furthermore, the APEX and RCS solutions’ modular style is designed to ensure flexibility to match specific application requirements. For example, it is possible for different terminals from the company’s high-power automotive range to be employed within the same housing basis. As an example, APEX 9.5-mm terminals (Figure 3) able to handle up to 150 amps can be employed for high-voltage applications as well as X-by-wire applications requiring very high current under standard 14 volts.
Meeting new market demands
The fast developing EV and HEV market is set to generate a wide array of novel and challenging high-voltage connector applications. Different vehicle manufacturers are pursuing different routes toward the goal of low or zero emissions, and in doing so will place new demands on connector suppliers.
Common characteristics are likely to include the need for exceptional levels of safety and personal protection, combined with an on-going drive to reduce costs, as well as weight and space requirements. At the same time, manufacturers cannot afford to compromise the high standards of reliability and durability expected by consumers for a new generation of low-emission vehicles. CS
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MARC CUSSET is global sales and marketing director/line EDS housing and high-power interconnect for FCI Motorized Vehicles Division (www.fci.com). Over the past 15 years, he has held various sales, marketing, purchasing, and engineering positions in the automotive component industry, including Tyco-Raychem and Siemens VDO.
