Oct 25, 2023

What is OCPP?

OCPP stands for Open Charge Point Protocol. It is an application protocol for communication between Electric Vehicle (EV) charging stations and a central management system, also known as a charging station network. OCPP was created to establish a standardized approach to the networking of charging stations for electric vehicles, which allows for better interoperability between the charging infrastructure from different manufacturers.

OCPP has become the de facto standard protocol in the EV industry because it is open and vendor-neutral. This standardization is beneficial because it ensures that different charging station hardware can communicate with any central management software that also uses the protocol. Thus, it provides flexibility for EV charging station operators to switch between different software back-end vendors without the need to replace the charging stations.

What OCPP could cover?

OCPP covers a range of functionalities, such as:

  • Remote monitoring and management of the charging station.

  • Authorization of charging sessions (e.g., via RFID, mobile apps).

  • Meter values collection for billing and monitoring purposes.

  • Firmware updates and maintenance.

  • Reporting of events and alarms.

  • Smart charging capabilities (e.g., adjusting charge rate in response to grid demand).

How it works?

  1. Communication Setup:

    • The charge point establishes a connection to the central system using OCPP over a network, which can be the internet or a private network.

    • This is typically done using WebSockets for continuous two-way communication, although older versions might use SOAP/XML over HTTP.

  2. Session Initiation:

    • When an EV is plugged into a charge point, the charge point communicates with the central system to authenticate and initiate a charging session. This can involve checking the user's credentials and verifying if the user is authorized to start charging.

  3. Data Transfer:

    • During the charging session, data is continuously transferred between the EV charge point and the central system. This includes meter values for billing, charging speed, and status updates.

  4. Control Commands:

    • The central system can send commands to control the charge point, such as remotely starting or stopping a charge session, setting charging rates, or scheduling charge times.

  5. Firmware Updates and Maintenance:

    • The central system can also manage firmware updates, diagnostics, and maintenance remotely, reducing the need for on-site visits.

  6. Session Termination:

    • Once charging is complete, or if the session is stopped by the user or the central system, the session is terminated, and final data is sent to the central system for record-keeping and billing purposes.

Features of OCPP:

  1. Interoperability:

    • OCPP enables different charging stations and central systems to work together, even if they are made by different manufacturers.

  2. Open and Vendor-Neutral:

    • Since it's an open protocol, it encourages competition and innovation, preventing vendor lock-in.

  3. Scalability:

    • It can support a few chargers to several thousand, making it suitable for various sizes of charging networks.

  4. Real-Time Communication:

    • Enables real-time information exchange for operational efficiency and user convenience.

  5. Smart Charging:

    • OCPP supports smart charging, which allows the power that is delivered to an EV to be controlled. This is important for demand response management and grid stability.

  6. Security:

    • Newer versions, like OCPP 2.0, include improved security features like secure firmware updates, secure logging, and improved authorization mechanisms.

  7. Customization and Extension:

    • The protocol is designed to be extensible so that it can be adapted to specific needs and incorporate additional features over time.

  8. Cost-Effectiveness:

    • By using OCPP, the costs associated with the development and maintenance of proprietary protocols can be reduced.

  9. Support for Various Use Cases:

    • OCPP supports a wide range of use cases, including public charging, workplace charging, fleet charging, and home charging scenarios.

Who wrote OCPP?

The protocol is managed by the Open Charge Alliance (OCA), a global consortium of public and private electric vehicle infrastructure leaders that maintain and promote the OCPP. The OCPP continues to evolve with advancements in EV technology, with versions such as OCPP 1.6 and 2.0 providing more advanced features and enhanced security measures.