OCPP Guidelines (2024)

Introduction to OCPP

OCPP (Open Charge Point Protocol) is an open standard protocol designed to enable standardized communication between electric vehicle (EV) charging stations and central management systems. By using OCPP, charging stations can interoperate with central management systems, enabling remote monitoring, control, billing, and other functionalities. Over the years, OCPP has evolved through several versions, with OCPP 2.0.1, OCPP 1.6J, and OCPP 1.5 being the most common versions in use today.

Overview of OCPP Versions

OCPP 2.0.1

OCPP 2.0.1 is the latest version of the OCPP protocol, offering enhanced features and improved performance. This version supports various communication methods such as SOAP and JSON and introduces new security features. OCPP 2.0.1 provides more charging control options and a flexible billing mechanism, improved transaction handling, increased security, and advanced device management capabilities. It supports ISO 15118 for plug-and-charge and smart charging requirements.

OCPP 1.6 (SOAP/JSON)

The OCPP 1.6 version introduced JSON implementation and expanded smart charging capabilities. The JSON version communicates via WebSocket, allowing data exchange in any network environment. The most commonly used protocol is OCPP 1.6J, which supports JSON format data over WebSockets to reduce data traffic and enable operation over networks without charging point routing. Key features include load balancing, central and local smart charging, and the ability for charging points to resend their information.

OCPP 1.5 (SOAP)

OCPP 1.5 is an earlier version still widely adopted by many charging facilities. It provides basic charging control and monitoring functions but lacks some of the advanced features and performance of later versions. OCPP 1.5 communicates with central systems via SOAP over HTTP, supporting local and remote transaction initiation, including billing metering.

Differences Between OCPP Versions

OCPP 1.6 vs. OCPP 1.5

• Message Communication: OCPP 1.6 supports WebSocket and JSON data formats for lightweight data communication.
• Smart Charging: Introduced additional smart charging functionalities.
• Status Information: Enhanced status information capabilities.
• Data Resending: Charging points can resend their information, such as the latest meter values or status.

OCPP 2.0 vs. OCPP 1.6

• Message Transfer: OCPP 2.0.1 introduced new message types and modified existing ones to improve efficiency and performance.
• Digital Certificates: Introduced a security mechanism based on digital certificates for enhanced device authentication and message integrity.
• Data Model: Updated data models to support new device types and functions.
• Device Management: Comprehensive device management features, including configuration, diagnostics, and software updates.
• Component Model: Flexible component model for describing complex charging equipment and systems, supporting advanced functions like V2G (Vehicle to Grid).
• Smart Charging: Enhanced smart charging capabilities, allowing dynamic adjustment of charging power based on grid conditions or user demand.
• User Authentication and Authorization: Improved mechanisms for user identification and authorization, supporting multiple methods and higher data protection standards.

How OCPP Works

OCPP operates on a client-server architecture where charging stations (clients) send requests to and receive responses from central management systems (servers). These interactions follow the formats and procedures defined by the OCPP protocol.

1. Charging Request: When a charging session is initiated, the charging station sends a request to the central system, including parameters like charging power and user information.
2. Validation and Response: The central system validates the request and sends a response indicating whether the charging can proceed and under what conditions.
3. Status Updates: During charging, the station sends periodic status updates to the central system for real-time monitoring.
4. Completion Notification: Upon completing the session, the station sends an end-of-charge notification with the session details.

Role of OCPP in EV Charging

1. Communication: Facilitates communication between EVSE (Electric Vehicle Supply Equipment) and CSMS (Central Management Systems).
2. Authorization: Manages the authorization process for starting a charging session.
3. Remote Configuration: Allows remote modification of charging settings.
4. Real-time Monitoring: Provides real-time status of the charging station (e.g., available, stopped, paused).
5. Data Reporting: Sends real-time charging data and power consumption information.
6. Remote Control: Enables remote control of charging operations (e.g., start/stop).
7. Fault Management: Reports real-time EVSE faults.
8. Reservation: Allows the reservation of charging slots.
9. Smart Charging: Implements load balancing to reduce grid load.
10. Firmware Management: Supports over-the-air firmware updates.
11. Remote Unlocking: Facilitates remote unlocking of connectors.

Operational Steps for OCPP

1. Device Configuration: Ensure proper installation and network connection of the charging station.
2. Software Installation and Configuration: Install OCPP-compliant management software and configure parameters like backend URL and authentication credentials.
3. Session Initiation: Start a session with the backend system and establish a network connection.
4. Charging Request: Input charging request details and send to the backend system.
5. Receive Commands: Await and execute control commands from the backend system.
6. Status Monitoring: Periodically check and report the charging status.
7. Session Termination: End the session after charging and process settlement information.

Considerations

1. Stable Network Connection: Ensure reliable network connectivity between the charging station and the backend system.
2. Correct Configuration: Properly configure all parameters to avoid communication errors or charging interruptions.
3. Regular Monitoring: Frequently check the operational status of the charging station and promptly address any issues.
4. Maintenance and Updates: Regularly maintain and update the charging equipment to ensure compatibility and optimal performance.

OCPP Functional Overview

Smart Charging

1. Load Balancing: Controls the charging power distribution within a station based on pre-configured limits.
2. Central Smart Charging: Central system manages charging limits based on grid capacity predictions.
3. Local Smart Charging: A local controller manages charging behavior within a group of stations, modifying power limits as needed.

OCPP 1.6 Functional Profiles

1. Core: Basic functions like starting/stopping charging, changing configurations, and reporting status.
2. Firmware Management: Functions related to downloading and installing firmware updates.
3. Reservation: Functions for creating, canceling, and modifying reservations.
4. Local Auth List Management: Functions for managing local authorization lists.
5. Smart Charging: Functions for scheduling and reporting smart charging plans.
6. Remote Trigger: Functions for remotely starting and stopping charging.

OCPP 2.0.1 Functional Modules

1. Data Transfer: Ensures real-time and accurate data exchange.
2. Authorization: Manages user permissions and authentication.
3. Security: Provides encryption and identity verification to prevent data breaches.
4. Transaction Management: Handles charging transactions and records charging data.
5. Metering: Monitors and records key data like power and voltage.
6. Billing: Calculates charges based on usage and generates invoices.
7. Reservation: Supports booking of charging services.
8. Smart Charging: Implements load balancing and other smart charging functions.
9. Diagnostics: Detects and diagnoses faults.
10. Firmware Management: Manages firmware updates.
11. Display: Shows status, pricing, and other information to users.

These features make OCPP 2.0.1 a comprehensive protocol supporting all aspects of charging station operations and management.