We recently had a discussion with Darren Simmons, VP Elec&Eltek Magnetic Products about some key points that you need to consider when designing an EV power supply relating to the magnetic components that might easily get missed and make the design stage more complicated.
Temperature
Temperature control is critical. In order to prevent thermal runaway in the inductor. This can be done by various different methods, utilising different core materials, alternate winding configurations, core gapping or the use of thermal potting compounds. Some of these will require the use of higher cost components, there is usually a price/ efficiency trade off to be made here.
Manufacturability
Its easy to over specify and push the envelope as to what the inductive materials can produce. Its better for long term use and ease of repeatability in manufacturing not to do this. Utilising a modular design, incorporating multiple functionality aids for a simpler PCB assembly when at the production line.
Lead-Time
When using higher specification materials and cores in your designs generally increases the lead times. Also, these EV charging components tend to be used in high volumes and therefore to reduce costs, sea freight is required. All these factors need to be taken into consideration early in the production planning.
Parasitic Capacitance
When potting compounds are used to help with heat dissipation there is also a secondary action.
The filters when potted lose impedance, this is called parasitic capacitance and there is a drop off in the performance of the components once potted, this needs to be taken into consideration when designing the inductors used.
Conclusion
As usual in these situations a lot of the problems can be alleviated by choosing the right design partners.
EEMPL being a market leader in the production and design of magnetic components for EV applications are experienced in spotting these issues early in the design cycle and their team of engineers are on hand to assist throughout.