Electric vehicle (EV) product development has traditionally centred around improving range and performance. However, choosing the right fuse is essential for protecting the EV and its components, and for ensuring the continued development of the technologies.
Changing climate
An EV is comprised of a number of expensive components, notably the electric motor and the battery pack. An essential aspect of the EV powertrain is the choice of fuses, required to protect these components from power surges and faults, both of which could be significantly damaging, says Sam Mudge.
Mudge is Product Manager for Eaton Bussmann, the electrical division acquired by Eaton in 2012. In a recent Automotive Megatrends webinar, Mudge and his colleague Saffiya Osman, Application Engineer, explained the importance of fuse selection for EVs and hybrid vehicles, and highlighted the increased complexity in fuse selection as vehicle electrification has evolved.
“In order for hybrids and EVs to become a viable option and compete with internal combustion engine (ICE) counterparts, there are some significant technology advances to make in a relatively short space of time,” said Mudge.
He is certain that as the popularity of EVs and hybrids grows, there will be a greater need and demand for the vehicles to obtain higher power and speed, coupled with longer range. These factors present a number of challenges for companies, but to allow OEMs to address these, they must first choose the right fuse for the right application.
Don’t scrimp
OEMs have a choice of two main types of fuses. The first is supplied by companies like Eaton Bussmann, and is “designed specifically with the application in mind”, explained Mudge. It is also typically implemented into the system “early in the design cycle, to best protect all the equipment around the fuse”.
The second type of fuse is a cheaper alternative, which comes “off the shelf” and is not capable of protecting certain applications. Mudge admitted that these are “great, but do not always offer the critical protection that fuses are designed for in their application.”
When choosing the latter option, Mudge thinks that “OEMs start to compromise on quality and performance.” He also reiterated the fact that the cheaper fuse does not offer adequate protection for high value components, and suggested that spending a little more on appropriate fuses is a far more sensible investment: “When we look at the cost effectiveness of an item such as a fuse, you really can mitigate against technical issues with much more expensive items such as commercial batteries and motors.”
To put things into perspective, using Eaton Bussmann’s fuses to protect all the necessary components of an EV or hybrid vehicle will cost around US$100. Using “off the shelf fuses” will allow OEMs to save “a few dollars,” said Mudge, but when the fuse is protecting a US$10,000 EV battery pack, it’s “critical” to spend a few extra dollars spent on a better fuse.
“To scrimp on the choice of fuse could really impact what you have when you get to the roadworthy vehicle. You are compromising very expensive components in the car that will cost significant sums of money if they are damaged,” he cautioned.
Moving on up
The choice of fuse is not just important within the EV or hybrid vehicle itself.
“It’s absolutely critical to have the appropriate fuse both within the charging station and the charging circuit. We do, and have done developments, for fuses in charging circuits,” he said.
Mudge pointed out the fact that both the vehicle and the charging stations are very expensive, “and so you need to be adequately protected against a fault or a short circuit in both. Also, you’re in a little bit of trouble if you have an EV and your charging circuit goes, as you can’t charge your vehicle.”
In short, the growing popularity of EVs and hybrid vehicles will ensure there is a “high growth market” for fuses, concluded Mudge. As for whether the rising demand will make the cost of components like electric motors drop dramatically, and therefore see the fuse selection become less critical, remains to be seen. But for now, Mudge is adamant that fuses are one of the most important components in EVs and hybrid vehicles.
Michael Nash
