EVSE

Overview

An Electric Vehicle Supply Equipment (EVSE) delivers electricity via EVSE ports to charging inlets located on electric vehicles (EVs). An EVSE may also be referred to as a charging station, charge point, or an EV charger. The meaning of these names often vary and are subject to interpretation within the industry.

There are three commonly referred to Types of EVSE. However, EVSE are modeled in Project Haystack using various combinations of evse-powerConverter, evse-dispenser, evse-port, and evse-cable. See the chapter Modeling EVSE for more details.

Types of EVSE

Level 1 AC EVSE

A Level 1 AC EVSE may deliver up to 2.5kW of AC power to an EV's charging inlet. The EV's onboard converter transforms the inputted AC power to DC power, which is used to recharge the EV's battery. This EVSE typically requires a 1-phase, 120V electrical input from a standard wall outlet.

Level 2 AC EVSE

Similar to a Level 1 AC EVSE, a Level 2 AC EVSE delivers AC power to an EV's charging inlet. However, a Level 2 AC EVSE is capable of delivering more AC power due to it's support for a higher input voltage or a 3-phase electrical input. Faster recharging times are possible as a result.

Level 3 DC EVSE

A Level 3 DC EVSE delivers DC power directly to an EV's charging inlet, eliminating the need for a converter onboard an EV. It is also referred to as a Direct Current Fast Charger (DCFC). In some cases, such as when an EV has a battery pack that is greater than 500VDC, there is still a DC-to-DC converter onboard the vehicle to allow recharging the EV using an earlier generation Level 3 DC EVSE that is not capable of delivering more than 500VDC output.

Typically Level 3 DC EVSE deliver more power and recharge EVs considerably faster than Level 1 or Level 2 AC EVSE. This is because they convert AC power to DC power with fewer space, weight, and cost constraints than converters designed to be onboard an EV.

Tagging EVSE Types

It is often difficult to estimate how long it would take to recharge an EV when referencing these EVSE types, or levels, for reasons including:

• The range of power that each EVSE type may deliver has increased in recent years
• Several available EVSE products may be considered a Level 2 AC and Level 3 DC type simultaneously
• These EVSE type definitions do not clearly convey what electrical input and output specifications apply to the EVSE
• Variety in EV battery sizes

Consequently, Project Haystack does not currently describe EVSE types, or levels, using standard tags to avoid ambiguity or repeated data.

Modeling EVSE

EVSE Power Converter

An evse-powerConverter models the power modules used to convert an electrical waveform to a dc form that is applied to a dc-evse-port. It may be contained within an evse-dispenser or in a separate dedicated equipment enclosure. An evse-powerConverter can contain zero or more evse-port.

EVSE Dispenser

An evse-dispenser dispenses electricity to an EV. It consists of a physical EVSE enclosure and its contents to which an evse-cable attaches. An evse-dispenser can contain zero or more evse-port.

EVSE Port

An EVSE port is modeled with the evse-port tags. An evse-port delivers electricity to a single EV charging inlet at a time. More than one evse-cable may be connected to a single evse-port, but only one may be energized at a time.

Electrical output specifications for an evse-port are described using attributes. An evse-port is described to deliver AC or DC power to an EV's charging inlet using the ac or dc tag, respectively. An evse-port may only have the ac or dc tag, but not both.

EVSE Cable

An EVSE cable is modeled with the evse-cable tags. An evse-cable models the electrical cable between an evse-port and an EV charging inlet used by an EV driver. evseCableType distinguishes the type of cable.

Example 1: All-in-one Level 2 AC EVSE with One AC EVSE Port

Example 2: All-in-one Level 3 DC EVSE with Two DC EVSE Ports

Example 3: Split System Level 3 DC EVSE with Two DC EVSE Ports for Sequential Charging

Future Work

The EV charging working group recently formed. The definitions presented should be considered preliminary and subject to change. We plan to add more definitions related to EV charging in the future. Specifically, future work will describe how to define attributes for evse-equip and may establish entities that address pantograph, socket, and wireless EV charging applications, which are less common.

If you are interested in contributing to the EV charging working group, then please reach out to WG 982 on the Project Haystack forum here.