How Do EV Fast Charger Stations Work?

With the National Electric Vehicle Infrastructure (NEVI) Formula Program set to provide $5 billion in funding towards the rollout of EV charger infrastructure, fuel and convenience retail marketers around the United States are gearing up to incorporate EV chargers into their sites.

Access to these NEVI funds requires the recipient to include a minimum of four 150 kw DC fast chargers (also referred to as Level 3 chargers) and maintain a 97% charger uptime in their charging stations. Unlike the Level 1 or Level 2 chargers commonly found at in-home charging systems and shopping centers, L3 chargers require an enormous amount of utility power and station infrastructure. For more information on NEVI requirements visit the U.S. Department of Transportation Federal Highway Administration website to review the Bipartisan Infrastructure Law.

Let’s take a look at the equipment these L3 fast charging stations require.

DISTRIBUTION TRANSFORMER

A distribution transformer is a utility-owned piece of equipment that delivers 480 VAC power to the charging station. This pad-mounted distribution transformer is the final step in the electric power distribution system and is responsible for stepping down the voltage from distribution lines to the necessary voltage for the switchgear equipment.

TRADITIONAL POST-AND-FRAME SWITCHGEAR

The switchgear is responsible for receiving the 480 VAC utility power, distributing power to on-site equipment, protecting the site from electrical faults, and converting the high-voltage 480 VAC power to the lower-voltages necessary for the switchgear equipment.

Traditionally, these post-and-frame switchgear systems have been comprised of an arrangement of mixed-manufacturer electrical panels. These panels include a disconnect panel, current transformer (CT) cabinet, distribution panels and a transformer. All of which requires an engineering design, permits, on-site wiring, and installation.

DC FAST CHARGER

A DC fast charger / Level 3 charger receives the 480 VAC power, as well as the 120 VAC power in some models, from the switchgear. The lower voltage 120 VAC power may be required to power the charger’s electronics like the user interface, network communications, and payment processing. Because EV batteries require DC power to charge, the charger will typically also handle the job of converting the 480 VAC power to DC power which is then transferred to the EV. The charger will facilitate the transfer of EV battery charging power, ranging between 300-900 VDC, via a fluid-cooled cable which helps mitigate the heat created by this massive power transfer.

EV POWER CABINET

Some DC Fast Chargers do not include integrated AC to DC power conversion capabilities. These chargers require an additional EV Power Cabinet to convert AC to DC power.

Now that you understand the basics of DC fast charging station infrastructure, let’s take a look at how Franklin Electric is streamlining these systems with the NexPhase™ Smart EV Switchgear.

NexPhase™ SWITCHGEAR

The NexPhase™ Smart EV Switchgear provides the entire electrical switchgear infrastructure needed to support up to four 150 kW DC fast chargers in a single enclosure. NexPhase™ eliminates the lengthy design process of traditional post-and-frame systems, which require additional costs to design and source a mixed-manufacturer panel system. Compared to traditional switchgear, NexPhase™ requires minimal onsite connections for only the incoming power and outgoing charger connections. This drastically reduces the on-site installation time required for a certified EV electrical contractor.

REMOTE EV INFRASTUCTURE MONITORING, TROUBLESHOOTING, & CONTROL

Unlike any switchgear of its kind, NexPhase™ features cutting-edge grid intelligence for switchgear and EV charger remote monitoring and control. An embedded monitoring system provides remote access to real-time health data with remote power cycling capabilities and automated alarms to facilitate condition-based maintenance planning.

NexPhase™ securely communicates with the UNITE™ user interface, providing user-friendly access to monitoring information including transaction analysis, energy consumption, charge duration, EV charger state, utility power monitoring, and more. Armed with these capabilities, Utilities can increase the resiliency of their chargers and help achieve greater uptimes (another requirement for NEVI funding is 97% uptime).

If you are a Utility looking to fast-track your DC fast charger rollout initiatives, learn more about how NexPhase™ can help you mitigate up-front design and installation costs, facilitate condition-based maintenance planning, and well as bolster charger uptime.