collection! In-depth discussion on the development of connector materials in the new energy vehicle sanelectric

collection! In-depth discussion on the development of connector materials in new energy vehicles###

The "three electric systems" of new energy vehicles, namely: electric drive, battery and electronic control system, which is also the core technology of new energy vehicles to distinguish traditional fuel vehicles, is a power system born as an alternative fuel vehicle starting system. In the past two years, the rapid growth of new energy vehicles has led to the sales of related supporting components. In this issue, on the development of connector materials in the new energy vehicle sandian, Powerwell Alloy has also brought corresponding material solutions.

Q: The connectors used in the three electric vehicles are developing in the direction of high voltage, high current and miniaturization, what are the requirements for the copper used in them?

The number of interconnect devices for new energy vehicles has multiplied, and power requirements are also rising. However, design space is still largely limited. Therefore, high voltage, high current and miniaturization are the main industry trends at this stage. Miniaturization requires copper to have a higher modulus of elasticity and strength to ensure connection reliability. In addition, the miniaturization of connectors makes the processing and molding conditions for parts more stringent, and while having high strength, it is necessary to have better formability, such as turning and bending. The increase in voltage and current requires further improvement of copper conductivity to reduce the temperature rise generated during the use of the connector. Therefore, balanced alloys that take into account both strength, conductivity and processability will be a major demand direction.

Powerway Material Solutions

EValloy60 copper-nickel-phosphorus alloy launched by Powerway Alloys, with a strength of >600MPa, a conductivity of ~60% IACS, and a cutting efficiency of ~80%, is one of the ideal materials for balanced alloys.

Q: New energy vehicle three electric is developing towards the trend of integration, lightweight and modularization, how do the materials used in connectors need to adapt to the development of this trend?

The integration and modularization of the new energy vehicle three-electric system makes the original chaotic variety of connectors realize the integrated panel integration through the top-level design of the platform, and there are more integrated connectors with customized ports. The integrated and integrated design has led to an increasing demand for large copper strips, including custom-shaped special-shaped copper rows.

In recent years, Bowei Alloy responds to the customized needs of customers with special-shaped copper, through the use of digital research and development platform, combined with digital simulation technology, multi-level simulation iterative optimization, rapid design tooling mold design and production process development, greatly shortening the product development cycle, meeting customer customization needs, and effectively supporting the integrated and modular design requirements of connector manufacturers.

Q: In practical applications, some connectors will be burned due to excessive contact resistance, or connector failure caused by irregular manual insertion, etc., how to solve Powerwell Alloy?

The strength of the connector material, the modulus of elasticity, etc. determine the size of the contact forward force. The positive force guarantees the reliability of the connection and is also a major factor affecting the contact resistance. If the mechanical properties of the connector material are insufficient, or the safety redundancy of the design is too low, the contact resistance caused by the reduction of the forward force will be too large during use, and then there will be serious failure problems such as heating and burning.

In addition, the use of automotive connectors is often harsh, such as: to adapt to cold weather and hot climates, as well as high-frequency vibration during driving. Therefore, the thermal stress relaxation and fatigue properties of the material are important factors affecting the contact forward force. In the design of connectors, the impact of these properties needs to be comprehensively evaluated and alloy materials with higher performance margins are selected.

EValloy46 copper-nickel-silicon alloy developed by Powerway has good conductivity, excellent mechanical properties, stress relaxation resistance and fatigue resistance, which can provide customers with higher performance redundancy design, and is an excellent copper alloy material for new energy vehicle connectors.

Q: Under the 800V platform architecture, what are the new requirements for connectors and the materials used in them?

The starting point for changing the voltage of the high-voltage system from 400V to 800V is the traditional way to increase the voltage. If the current is maintained, the charge and discharge power can be increased at the same time, thus achieving a super fast charge. If the same charge and discharge power is maintained, a smaller current can be used to transmit, achieving a lower line loss, thereby improving energy utilization efficiency.

However, the problem is that the entire set of electrical components, including connectors, requires higher electrical insulation strength to ensure safety during operation. At the same time, the local arc discharge problem of the connection part brought by the high voltage, the EMC electromagnetic interference problem of other sensitive components caused by the voltage and frequency increase, etc., will promote the reliability, volume and electrical performance of the connector to increase, and the design and quality upgrade of the connector is an inevitable development trend.

The 800V platform architecture has the most significant impact on HVDC relays/contactors. HVDC relays/contactors play a role in high voltage circuit control and safety protection. The voltage and current of the 800V platform is higher, the on-off arc is more serious, and the performance requirements of the high-voltage DC relay/contactor such as voltage resistance, current carrying capacity, arc extinguishing, service life, etc. The product needs to be improved in many aspects such as contact material and arc extinguishing technology. Related studies have shown that tellurium copper alloy in the high-voltage, high-current on-off process, can significantly reduce the probability of arcing and adhesion of the paired contact material, is an ideal contact material.

The tellurium copper alloy EValloy91 produced by Powerway Alloy can provide rods, wires and rows, with excellent conductivity, turnability and cold heading deformation, as well as excellent resistance to arc ablation and adhesion, which can effectively help the quality and performance upgrade of HVDC relays/contactors.

The electric drive system is another challenge for the 800V platform architecture. The increase in motor voltage will bring about an increase in current and temperature, and higher heat dissipation efficiency requirements have led to the widespread use of oil-cooled technology in 800V motors. The cooling oil of the motor is a common corrosion problem for the bearing. In addition, the increase in motor speed further affects the wear life of the bearing.

BearMet350, a high-strength, wear-resistant copper-nickel-tin alloy, is developed for complex and harsh service conditions, and its corrosion resistance is comparable to that of nickel-based alloys, while also having a very low coefficient of friction and ultra-high strength, which can provide sufficient strength, durability and stability under extreme load and corrosion conditions. The BearMet350 is therefore an ideal bearing material for 800V motors. More new energy vehicle material solutions,