How to build a fast, flexible EV charging network

Article By : Henrik Mannesson

In the EV future, semiconductor-based designs will enable grid operators flexibility and speed to better manage energy distribution.

The transition to electric vehicles (EVs) looks inevitable as governments around the world commit to sustainability goals and the automotive industry plans to invest more than $330 billion through 2025 to advance vehicle electrification.

But what happens when thousands of EVs in a community plug in simultaneously and place unprecedented demands on the electric grid?

EV charging needs to be quick, affordable, safe, and robust. Therefore, providing a flexible infrastructure to generate, store, transmit and distribute the additional power is crucial for the electrification journey. And semiconductor technology is key to make charging more convenient, affordable, and sustainable.

Faster charging to put more EVs on the road

Change often creates uncertainty for consumers until they trust a product. Prospective EV buyers are no different. They need confidence about driving range, availability of charging stations and the time required to power up and get back on the road. Convenience and affordability are critical as the family car must be ready for a quick drive to the supermarket as well as a last-minute day trip. Here, cutting-edge semiconductor technologies will play a significant role in making that happen. Take, for instance, embedded processors like C2000 real-time microcontrollers, which work alongside isolated gate drivers and gallium nitride (GaN) power devices to boost charging efficiency.

Size matters when scaling up efficiency, so reducing the size of portable DC chargers like DC Wallboxes can mean big gains and better cost effectiveness. Here, GaN technology’s ability to operate at higher switching frequencies in multi-level power topologies means engineers can design smaller magnetics into their power systems, reducing the cost of components that use copper and other raw materials.

Not surprisingly, therefore, fully integrated GaN power devices are enabling faster and more efficient charging than traditional silicon-based materials. Also, multi-level topologies can be more efficient, which reduces the power required for heat dissipation or cooling. That, in turn, can also help reduce total cost of ownership.

Figure 1 GaN semiconductors are winning prominence in EV charging designs. Source: Texas Instruments

Meanwhile, the DC fast charging stations’ capacity has increased significantly. Where the standard was once 150 kW, we are now looking at capacities of 350 kW and beyond, and the improvements will continue. As a result, EVs will charge faster, which will help ensure chargers are not the bottleneck for getting more EVs on the road.

Technology to take the chore out of charging

On a macro level, optimal power distribution and load sharing are vital to ensure that infrastructure is flexible during peak usage. Smart designs and bi-directional charging will help manage these challenges by gauging consumers’ habits and adjusting in real-time.

Figure 2 Bi-directional charging designs are highly suitable for EV charging stations and energy storage applications due to merits such as power density, cost, weight, galvanic isolation, and high-voltage conversion ratio. Source: Texas Instruments

Since most people will be at home after work, their simultaneous charging needs will need to be managed. Semiconductor technology can enable more flexibility for managing energy distribution through smart energy metering that takes the chore out of charging.

Improved robustness in current sensing and voltage sensing technologies is helping provide connectivity with the grid to optimize energy consumption. Similar to smart thermostats that are sensitive to weather patterns, smart energy metering using Wi-Fi and sub-1 GHz standards such as Wi-SUN can track real-time adjustments in energy pricing and make better power-management decisions. In the United States and Europe, solar-powered homes are expected to be a big part of the equation in storing energy and charging EVs.

Bi-directional charging will allow consumers to send surplus power back to the grid. For that, energy metering technology must measure power distribution flows between EVs, consumers’ batteries, and the grid. So, bi-directional charging stations equipped with smart energy metering may be transformational for modern workplaces as EVs sit idle while their drivers work, allowing grid operators to match solar and wind power generation with demand.

A familiar transaction goes electric

Time is at a premium, so shortening the charging process is important. This means reducing charging time on the road and maximizing convenience. Drivers have long been accustomed to gas stations where they can fill up and pay in a swift, simple transaction. Technology can provide similar payment and connectivity convenience for EV drivers.

Take the example of Sitara processors with Linux software, which support Open Charge Point Protocol (OCPP) and the ISO 15118 standard vehicle-to-grid communication interface. That allows processors to enable seamless transactions and information exchange between EVs, charging stations, and utilities.

Ultimately, consumers will value the convenience and availability of charging stations. This will help reduce range anxiety and further drive demand for EVs. Whether improving accessibility, convenience or affordability, semiconductor technology will be a key part of the charging infrastructure that will power the transition to electrification.

This article was originally published on EDN.

Henrik Mannesson is general manager for worldwide grid Infrastructure at Texas Instruments.

Leave a comment