New Tech Tuesdays: Scaling High-Voltage Interconnection Systems for EV Architectures
Key Highlights
- High-voltage interconnects must handle substantial current while minimizing heat, mechanical stress, and space requirements in EVs.
- Scalable contact architectures allow for tailored power delivery, supporting different vehicle sizes and performance needs without unnecessary complexity.
- Design considerations include routing, accessibility, environmental sealing, and touch safety to ensure reliable and serviceable high-voltage systems.
New Tech Tuesdays
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The increasing trend toward vehicle electrification has changed the demands placed on high-voltage interconnects. Beyond carrying substantial current between the battery, inverter, motor, and power-distribution equipment, these systems must fit within limited installation space while controlling electrical losses, heat, and mechanical stress.
In this week’s New Tech Tuesdays, we examine how scalable contact architectures and flexible connector packaging help engineers optimize high‑voltage interconnects for different vehicle platforms, and why electrical, thermal, mechanical, and serviceability requirements must be balanced to achieve reliable EV power distribution.
High-Voltage Interconnection Systems Carry More Than Current
In an electric vehicle (EV) or hybrid electric vehicle (HEV), the high-voltage network connects multiple power-conversion and propulsion subsystems. The US Department of Energy states that vehicle power electronics process and control electrical energy flow, with inverters converting battery-supplied direct current into alternating current for the traction motor.[1]
Every connection along that path contributes some electrical resistance. Since resistive power loss increases with the square of current, even a small connector resistance can become significant as current rises. The resulting heat affects conductor selection, terminal design, surrounding materials, and the thermal margin available under sustained load.
Rated current by itself provides incomplete selection criteria. Engineers need to consider conductor cross-section, ambient temperature, duty cycle, terminal resistance, and the connector’s validated operating conditions. Changes in any of these conditions can affect the connector’s current-carrying capacity and thermal performance.
Matching the EV Connector to the Architecture
A mid-power passenger vehicle and a heavier all-wheel-drive vehicle place distinctly different demands on EV power distribution. Acceleration, towing, hill climbing, and sustained operation under load can require higher current delivery, but selecting the largest available connector for every vehicle may add unnecessary cable mass, packaging volume, integration complexity, and cost.
A tiered high-voltage interconnection system gives engineers another option. An EV/HEV platform can use an interconnect sized for its expected load profile while retaining a related, higher-capacity architecture for more demanding vehicle options. This approach supports design reuse without forcing every model to carry the penalties associated with the highest power tier.
The US Department of Energy identifies reduced weight and volume, improved efficiency and reliability, and modular, scalable design as important objectives for electric-drive systems.[2] Connector selection contributes to each of these factors since the interconnect can influence cable size, routing, thermal performance, assembly space, and mechanical interfaces.
Packaging and Serviceability Join the Circuit
Selecting the conductor size is only one part of high-voltage cable integration. High-voltage cables also require routing clearance, bend space, strain management, shielding continuity, and access for assembly. Connector orientation can determine whether the cable follows a practical path or competes with structural members, coolant lines, and other nearby electronics.
Service access deserves equal attention. Lever-assisted mating, visible assurance features, and configurable cable exits can simplify installation and help technicians verify that a connection is fully seated. For high-voltage equipment, touch protection and environmental sealing are also essential design considerations. International Electrotechnical Commission (IEC) 60529 defines the IP Code, which classifies enclosure protection against access to hazardous parts, ingress of solid foreign objects, and harmful effects caused by water ingress.[3] By addressing routing, accessibility, and protection early in the design process, engineers can create safer and more serviceable high-voltage systems.
The Newest Products for Your Newest Designs®
TE Connectivity’s HC-STAK 25 XE High-Voltage Interconnection System targets mid-power EV and HEV applications. The system supports up to 1,000VDC and up to 296A continuously at +85°C with a 70mm² conductor. Its layered 2.5mm fork-terminal architecture provides up to 40 contact points per circuit, while optional bidirectional cable routing permits 180° plug rotation. A cam-driven lever and front-facing connector position-assurance feature support installation and service access.
For higher-output and heavier vehicle platforms, the TE Connectivity HC-STAK 35 High-Voltage Interconnection System supports up to 1,000VDC and up to 400A continuously at +85°C with a 95mm² conductor. Its 3.5mm double-ended fork terminals provide up to 64 contact points per circuit. Both systems specify a −40°C to +125°C operating range and incorporate shielded, touch-safe, vibration-resistant construction for demanding vehicle environments.
Tuesday’s Takeaway
Selecting a high-voltage interconnection system is ultimately an exercise in balanced engineering. The best choice provides sufficient current capacity and design margin while controlling resistance, heat, cable mass, packaging demands, and service complexity. Connectors with different current tiers allow engineers to use a common design approach while matching interconnect performance to each vehicle’s specific power requirements.
Sources
[1] https://www.energy.gov/cmei/vehicles/power-electronics-research-and-development
[2] https://www.energy.gov/cmei/vehicles/electric-drive-systems-research-and-development
[3] https://www.iec.ch/basecamp/ingress-protection-ip-ratings-guide
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