Engineering the EV future

By Harvey Wilson   |   November 4, 2021   |   Provided By Avnet Silica

Worldwide annual sales in electric vehicles (EVs) set a new high in 2020, reaching 3.2 million units according to figures from Statista. That is approximately 65% up on the sales activity recorded for the previous year. The availability of a wider variety of different models with improved performance parameters, combined with government incentives aimed at lightening the costs involved, are leading to ever greater EV traction. There are still certain issues that need to be addressed, however, if further uptake is to be encouraged.

A series of webinars on EV charging infrastructure, hosted by Avnet Silica, is available for registration here.

EV progression - Navigating the road ahead

Though EV sales are now gaining greater momentum, there are a number of places where persistent technical or logistical obstacles exist. Effective ways need to be found to overcome them if things are to proceed as planned. Let’s look at each in turn.

Considered to be the most prominent of these issues is ‘range anxiety’. This is a term that describes the cautiousness of car buyers to embrace EV technology, because they do not have enough confidence that there is going to be adequate charging infrastructure available to ensure they can complete longer journeys. A greater density of publicly accessible charging points will help to deal with this and allay people’s doubts.

Another worry is how straightforward the charging process will be. People are used to being able to fill up the fuel tanks of their cars within just a few minutes. EV charging is a longer procedure. More widespread access to rapid charging equipment is therefore going to be mandated, thereby ramping up the speed in which charging can be completed and making it less of an inconvenience for users. To shorten the period that charging takes within a domestic environment, increasing numbers of DC wallboxes will be installed for use instead of conventional AC mains connections.

Whereas home chargers are generally limited to drawing power from a single phase supply, which is relatively restrictive, highway charging stations will be able to tap into the three phase supply network. The upshot of this is that 22kW (for fast charging) and 43kW (for rapid charging) power levels can be benefitted from, resulting in substantially quicker charging rates.

The incorporation of wide bandgap power discretes (based on either SiC or GaN technology, rather than conventional Si) and accompanying gate drivers in EV powertrains will be pivotal. These will allow higher voltage levels to be supported, with 400V systems being replaced by ones with 800V ratings. This will translate into EVs that are markedly more efficient, with less power losses experienced, as well as being lighter. As a consequence, the range such vehicles are going to be able to travel will be markedly extended, thereby, once again, tackling the range anxiety issue.

Implications for the grid

The additional impact that large-scale EV adoption will put on existing electricity distribution networks should not be overlooked. The European Union (EU) expects there to be over 30 million EVs on its roads by 2030. This will represent a considerable drain on the grids of its respective member states. There will be a need for smart metering technology, supported by advanced connectivity, to help balance supply and demand across the grid and avoid the risk of power outages occurring.

Greater use of on-site renewable energy generation will also have a significant role to play when it comes to resolving this problem. It seems certain that photovoltaic systems or wind turbines will be located at charging stations in the future, thereby supplementing the electricity coming directly from the grid. There will also be micro-generation sites at a large proportion of people’s homes.

It is now recognised that energy storage reserves are going to be responsible for assisting with the maintaining grid stability at times of highest consumption. The advent of smart chargers will permit regular communication with the grid, so that load being placed on it can be better managed and outage situations safeguarded against. There is even the prospect, through implementation of bidirectional charging systems, that the electricity stored in stationary EV batteries might be pushed back into the grid for load balancing purposes. That would mean supply could be better matched against the actual requirements during peak periods. It could result in EV owners generating revenue from the utility companies, which would allow them to compensate for some of the original costs of buying the vehicle.  

To make replenishing of vehicle batteries at charging stations as simple and secure as possible, appropriate LPWAN technology such as NFC fobs will need to be utilised. This will enable the charging equipment to get any necessary information, including the customer’s unique ID and key specifications relating to their vehicle, such as maximum battery capacity. This confidential data may then be securely transferred to the cloud to get user authentication. The user can get authenticated, with tariff information and local grid balancing settings being retrieved at the same time, before charging is subsequently initiated. Well-defined layouts for the human machine interfaces (HMIs) used in charging stations and home-based DC wallboxes will also be paramount. They must be rendered in such a way as to deliver enhanced user experiences - their operations being highly intuitive and responsive, with any potential for frustration being mitigated.  

The migration towards EVs becoming the dominant form of vehicle on our roads is now clearly underway, with genuine signs that they will become increasingly pervasive over the course of the next decade. Nevertheless, there are still several major engineering challenges that are holding us back from reaching wholesale adoption. The widespread roll-out of next generation charging infrastructure will be the foundation upon which vehicle electrification is dependent. Through accelerated charge times and introduction of EV models capable of supporting longer ranges between recharges, it will be possible for many of the concerns that car buyers still have about ditching their internal combustion engine cars to finally be alleviated.

Core technology for EV charging

The companies providing the core technology behind EV charging infrastructure - in terms of power electronics, wireless connectivity, microcontrollers, HMIs, power-line communication, web services and security - are continuing to find innovative new approaches that will drive further EV proliferation. Avnet Silica will be hosting a webinar series looking at all aspects of electric vehicle infrastructure later this month  (30 November to 2 December 2021). The ‘EV Charging Discovery Days’ webinars will feature representatives from valued supply partners like STMicroelectronics, Microsoft, Quectel, onsemi, NXP and Intech.

To get more details and watch this on-demand webinar series click here.

Follow Avnet Silica on LinkedIn

About Author

Harvey Wilson

Harvey Wilson is a Systems Engineer Professional (Smart Industry) for Avnet Silica in the EMEA regio...

View Bio