Wondering what are the different electric vehicle (EV) charging standards and protocols? In this blog, you will learn the various EV charging protocols and standards available and understand their differences and variations.
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As the electric vehicle industry grows, the adoption of global standards for EV chargers and network interoperability is increasing.
Standardized charging protocols are crucial for efficient and safe communication in the EV charging ecosystem. They help CPOs, EMSP, EV regulators, and EV drivers simplify access control and load management processes.
Participants In EV Charging System
We can identify various participants in the EV charging system who communicate with each other based on protocols.
|CPO||Charge Point Operator. Operates a network of charge points.|
|EMSP||E-mobility Service Provider. Gives EV drivers access to charging services.|
|Hub||Connects of multiple CPOs with multiple EMSPs.|
|SCSP||Smart Charging Service Provider. Provides smart charging services to other parties.|
|NAP||National Access Point. Provides an available database with all (public) charging locations.|
|NSP||Navigation Service Provider. Provides location information for EV drivers to find charge points.|
👉 Related read: Learn the key differences between CPOs and EMSPs.
The CPO bills the eMSP for the cost of charging sessions. Separately, the EMSP charges the EV driver for the session costs. The CPO does not directly set prices for the end driver.
In the picture below we show the use of protocols and standards in the EV charging system:
Why Are EV Charging Protocols Important
- Interoperability: They ensure that various EV infrastructure providers are compatible, allowing a wide range of EVs to use the same charging stations and seamlessly integrating different hardware and software systems.
- Communication & Data Exchange: They enhance coordination among participants by structuring communication and enabling secure, efficient exchange of crucial information, including billing details, user credentials, and technical directives.
- Seamless Transactions: They streamline the payment process for EV drivers, facilitating quick and effortless transactions during charging sessions.
- Monitoring: They monitor key parameters during charging to mitigate risks, facilitating communication and data exchange between the EV, charging station, and central or energy management systems.
- Smart Charging: They optimize the charging process for electric vehicles by making dynamic adjustments based on grid capacity and electricity rates, promoting energy efficiency.
- Plug & Charge Capability: They have features that automatically start charging when the vehicle connects to a charger, making it more convenient for users and reducing time waste.
- Safety: They enforce safety standards, addressing physical and cyber security concerns to protect vehicles, passengers, and data from potential hazards.
Central System – EV Charger Protocols
These standards and protocols cover communication between EV charging central systems and charging stations, primarily for infrastructure monitoring and management.
Examples of communication (Central System – charging station):
- One party requests an operation (e.g., start charging), and the other confirms or denies it.
- A party communicates its status to the other (e.g., connector available for charging).
- One party sends a charging summary to the other (e.g., CPO sends eMSP a summary).
Open Charge Point Protocol (OCPP) is an EV charging communication protocol between an EV charging station and a central management system. It’s a free-to-use protocol widely adopted by various vendors globally.
It was established by Open Charge Alliance (OCA) for the EV infrastructure market and has emerged as a must-have standard for ensuring interoperability among EV charging manufacturers, charging network operators, and software providers.
OCPP 1.6 is used for communication between EV charging stations and a central system.
OCPP 1.6 supports the extension of ISO 15118 (Plug & Charge) aka OCPP 1.6+.
OCPP 2.0.1 is the most recent version, released in 2020. It offers new features and improvements, such as support for ISO 15118 (Plug and Charge), enhanced security, and overall improved performance.
OCPP 2.0.1 has full support for ISO 15118 (Plug & Charge).
It’s a robust and flexible protocol that enhances the EV charging experience for everyone.
IEC 63110 is an international standard for the management of electric vehicle charging and discharging infrastructures by the International Electrotechnical Commission.
Like OCPP, it is expected that IEC 63110 will bring significant advancements to the EV charging industry. With its emphasis on interoperability and compatibility, it aims to refine business processes, enhancing the overall user experience and system efficiency.
EV Charging Roaming Protocols
These roaming protocols define various operations between CPOs and EMSPs. Most common examples are: searching for chargers from other operators, driver authorization, session management, and more.
Some other examples of communication:
Smart EV Charging: Unlocking Its Full Potential
1) EMSP → CPO:
- Request the initiation of charging at a station
- Request the termination of charging at a station
- Retrieve a list of charging stations for display
- Request an immediate reservation for charging (either reserve now or make an instant reservation)
- Request cancellation of charging reservation
- Request connector unlock (when physically stuck due to an electromechanical lock)
2) CPO → EMSP:
- Driver verification prior to charging (authorization at session start by RFID or Plug&Charge by vehicle certificate)
- Notification of charging initiation (session start event)
- Update on charging progress (session update event)
- Notification of charging termination (session end event)
- Send charging summary (charge detail record as CDR)
All the roaming standards listed below have the following common features:
- Roaming: Enables EV drivers to use any charging station, no matter who operates it or provides the service.
- Tariff Management: Allows CPOs to communicate their tariffs to EMSPs for cost evaluation between the two. While CPOs set prices for EMSPs, EMSPs establish prices for EV drivers.
- Session Management: They facilitate the process for EMSPs to initiate, terminate, and oversee charging sessions.
- EV Billing: Simplifies the billing process from CPOs to EMSPs for charging services.
- Cost Reduction: Provides standardized interfaces for clearing transactions with other EMSPs.
- Increased Efficiency: They provide standardized interfaces for clearing transactions with other EMSPs, enhancing efficiency in operations.
- Charging infrastructure availability: As long as the driver’s EMSP is part of the roaming network, he/she can access the chargers of all the other CPOs in the roaming network.
- Improved Security: Facilitates secure data exchange between EMSPs through digital signature authentication.
Open Charge Point Interface (OCPI) is a communication protocol for EV charging between CPOs and EMSPs, facilitating direct communication. Communication can also occur through a hub, connecting multiple CPOs, EMSPs, and more.
O.C.P.I. allows EV drivers to use any charging station, irrespective of the CPO or EMSP involved.
Expert’s View: OCPI is gaining traction globally. Through the evRoaming4EU project, it enhances EV charging services across Germany, Austria, Denmark, and the Netherlands.
In this protocol, participants can be CPOs, EMSPs, hubs, National Access Points (NAPs), National Navigation Providers (NSPs), and Smart Charging Service Providers (SCSPs).
Open InterCharge Protocol (OICP), developed by Hubject in 2012, ensures the interoperability of charging infrastructure.
This protocol provides a standardized means for CPOs and EMSPs to communicate and exchange essential information.
With OICP, users can effortlessly find and access charging points. They can also view dynamic data about these points, including real-time availability and pricing information, and can easily initiate and terminate charging sessions.
OICP operates differently from OCPI. While OCPI allows direct communication between CPOs and EMSPs, OICP channels all communications through a single Hub platform, serving as a central communication point for all transactions and interactions. This unique approach ensures streamlined and efficient communication within the EV charging network.
Open Clearing House Protocol (OCHP) connects EV participants in the field of electric mobility charging infrastructure. This protocol simplifies communication between parties’ back-end systems and a clearing house system.
OCHP is still under development, but many EMSPs in Europe and North America already use it. The latest version of OCHP is 1.4.
The eMobility Interoperation Protocol (eMIP) is an open communication protocol developed by GIREVE (France).
It facilitates interactions between Charge Point Operators (CPOs) and eMobility Service Providers (EMSPs).
IEC 61851 sets international requirements for conductive charging systems for electric cars.
This standard is divided into sections, each addressing a distinct aspect: general system requirements, connector types, and testing and certification criteria.
This protocol falls under both Central System – EV Charge Protocols and Roaming Protocols.
It’s notable for covering multiple areas in one, as it is divided into sections. Each section addresses a different aspect: general system requirements, connector types, and testing and certification criteria.
Electric Car Charger Standards and Protocols
These are EV charging standards and protocols that cover communication between charging stations and vehicles.
These are EV charging connector types highlighting the standards in North America, Europe, and the Asian region:
ISO 15118 Plug and Charge
ISO 15118 is an international charging standard for electric vehicles published in 2013 by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC).
This protocol establishes a communication interface for electric vehicles and charging infrastructure, promoting two-way power flow between EVs and the grid. It enhances the charging process by facilitating seamless communication between EVs and charging stations.
Key Features Of ISO 15118:
- Plug and Charge: Automates the authentication and authorization process for charging, eliminating the need for driver intervention.
- Smart Charging: Allows dynamic communication between EVs and charging stations, negotiating charging rates and schedules based on grid conditions and EV battery levels.
- Vehicle-to-Grid (V2G): Supports the ability of EVs to discharge energy back to the grid, aiding in grid stability and energy cost reduction.
Combined Charging System (CCS) stands as a foundational standard for charging electric vehicles, including AC and DC charging, communication between EV charging stations and cars, load balancing, authentication, authorization to charge, and vehicle couplers (connectors at the end of charging cables and corresponding inlets in vehicles).
“Combined” means the addition of rapid DC to Type 1 and Type 2 AC connectors, creating CCS1 and CCS2 connectors. These connectors can deliver up to 350 kW of power. While CCS1 is standard in North America, CCS2 is prevalent in Europe.
Milestone: In 2012 CSS was introduced by Audi, BMW, Daimler, Ford, General Motors, Porsche, and Volkswagen and quickly gained traction.
Tesla has incorporated this connector in all its North American vehicles since 2012, including its DC-powered Superchargers and Level 2 Tesla Wall Connectors for home and destination charging.
That’s why the North American Charging Standard (NACS) protocol is so popular.
It provides both AC and DC charging through a compact plug that uses the same pins for both types of charging and supports up to 1MW of power on DC.
Given Tesla’s dominance in the North American EV market and its extensive DC EV charging network in the U.S., NACS has become the most widely used standard.
The NACS protocol is a promising EV charger standard that improves EV charging in North America, aiming to enhance the user experience, reduce costs, and encourage innovation.
Expert’s View: NACS is making strides in the EV industry, especially with the support of Tesla. Automakers such as Ford, General Motors, Fisker, Rivian, Volvo, and Polestar will adopt NACS around 2025.
👉 Related read: Tesla Revenue & Production for 2023
CHAdeMO fast charging standard is prevalent in Asia, specifically in Japan and China.
It is faster than AC charging as it can deliver power directly to the EV’s battery through DC charging.
With CHAdeMO charging, an EV can range up to 100 miles in just 20 minutes.
ChaoJi, synonymous with CHAdeMO 3.0, represents a groundbreaking advancement in ultra-high-power charging technology for electric vehicles (EVs).
This protocol is designed to offer exceptional charging capabilities, focusing on high power and rapid charging.
SAE J1772, or Type 1 connector (IEC 62196 Type 1), is a North American EV connector standard maintained by SAE International.
It can charge single-phase AC at various rates, ranging from 1.44 kW for portable devices to 19.2 kW for hardwired equipment, based on the 5-pin J1772 protocol.
GB/T charger standard refers to a series of GB/T standards, specifically in the GB/T 20234 group, which govern the AC and DC fast charging of electric vehicles in China.
These standards were revised and updated by the Standardization Administration of China in 2015.
Choosing Your EV Charging Partner
Tridens’ EV charger software stands at the forefront of EV charging technology, maintaining 50.000+ charging stations and ensuring compatibility with 25+ charger models.
We hold certifications for Charge Point Protocols and are OCPP compliant (OCPP 1.6 J & OCPP 2.01). Also, we ensure your hardware compatibility and smooth vehicle-to-grid (V2G) communications through adherence to ISO 15118 (Plug and Charge standard).
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