Rugged Interconnects for Harsh Environments eBook

Factors for increased HEV and EV sales include favorable government policies and support in terms of subsidies and grants, tax rebates, and other non-financial benefits. Proactive participation by automotive OEMs is also starting to drive the global electric vehicle sales. Almost every automotive manufacturer has HEV or EV vehicles in its future production schedule, and many of these models are coming onto the market right now. Consumers are realizing that the latest electric vehicles offer many advantages over traditional internal combustion engines (ICE). POWERTRAIN BASICS The powertrain of an EV is a simpler and more efficient system compared to ICE systems. EVs can run solely on electric propulsion or they can work alongside ICE systems in HEVs. An EV system has fewer parts by up to 60%, and even fewer moving parts. At its core, a standard EV system contains a charger, battery pack, converter, controller, and motor. • The charger converts power received through the charge port from AC to DC and controls the amount of current flowing into the battery pack. • The battery pack is made up of multiple Lithium- ion cells and stores the energy needed to run the vehicle. Battery packs provide DC output. • The inverter transfers DC power from the battery pack to AC to power the electric motor. • The electric vehicle controller is the electronics package that operates between the batteries and the motor to control the electric vehicle’s speed and acceleration, much like a carburetor does in a gasoline-powered vehicle. • The electric motor converts electrical energy to mechanical energy to move the vehicle via

a simple single or dual speed transmission to reduce wheel speed and multiply torque.

POWERTRAIN CONNECTOR REQUIREMENTS In all automotive applications, connectors must offer high reliability performance in terms of resistance to heat, shock, vibration, and other environmental conditions. In addition, powertrain systems require rugged and reliable interconnect solutions that can handle higher currents. For example, an EV motor can run anywhere from 96 to 800 Volts DC. HEVs typically feature nominal pack voltages ranging from 96 V to 200 V, while EVs must support 400 V to 800 V and higher. A three-phase AC motor is most likely operating at 240 V with a 300 V battery pack.

One downside of higher voltages is the demand for higher-voltage-rated connectors.

POWERTRAIN CONNECTOR TREND: A SHIFT TO FLOATING BOARD-TO-BOARD Previously, wire-to-board connectors were commonly used in HEV and EV drivetrain applications. This includes connectivity for motor controllers, inverters, and more. However, wire-to-board connectors take up more real estate and can often be more taxing during the integration and assembly process. New board-to-board connectors that feature a floating contact system simplify assembly and reduce labor costs, all while offering space savings. These versatile board-to-board connectors combine high voltage ratings up to 125 V AC/DC in a small footprint with a 1 mm pitch. Offering high temperature resistance up to 140°C, new connector designs with a floating contact design provide superior vibration resistance for more reliable operation.


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