How to Implement OCPP Protocol in Your EV Charging Applications

How to Implement OCPP Protocol in Your EV Charging Applications

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To implement the OCPP (Open Charge Point Protocol) in your charging application, you’ll need to follow a structured approach involving protocol understanding, architecture design, and integration with charging stations and back-end services. Here’s a step-by-step guide:

1. Understand OCPP Protocol

OCPP is an open-source communication standard used between EV charging stations (Charge Points) and Central Systems (CS). It enables interoperability between different charging hardware and software providers.

Versions:

  • OCPP 1.6: Widely used, stable, supports WebSockets and SOAP.
  • OCPP 2.0.1: Newer, supports JSON over WebSockets, improved security, and better smart charging capabilities. 

2. Choose OCPP Libraries or SDKs

Instead of building everything from scratch, you can use existing libraries that handle OCPP messages and protocol specifications. Some popular ones include: 

  • Python: 
  • Java: 
      • STEVE → Open-source Java OCPP implementation with a web interface
      • OCPP-J → Java OCPP client library 
  • Node.js 
      • OCPP-js → Lightweight library to build OCPP-compatible applications 
  • C#/.NET: 
    • OCPP.NET → Open-source C# library with OCPP 1.6 support

🛠️ 3. Architecture Design

You’ll need the following core components:

  • Charging Station (EVSE): Acts as the client, running OCPP code to connect to the backend.
  • Central System (CS): Backend server that handles communication, transactions, and data processing.
  • WebSocket/SOAP Communication Layer: OCPP uses WebSocket’s or SOAP for bi-directional communication.
  • Database: Store charge point details, session history, energy consumption, etc.
  • Authentication and Security: Secure data transfer using TLS (Transport Layer Security) and proper authentication.

4. Implement OCPP Communication

📍 For a Charging Station (EVSE) Client:

  • Establish a WebSocket connection to the central system.

📍 For the Central System (CS):

  • Handle OCPP messages, log them, and respond accordingly.

5. Implement Key Features

Once you have the basic OCPP communication in place, you’ll need to add features like:

  • Remote Start/Stop: Control charging sessions remotely.
  • Meter Values: Collect and store charging data (kWh, voltage, etc.).
  • Heartbeat: Periodic signals to verify that the charge point is still connected.
  • Reservation & Availability: Allow users to reserve charge points.
  • Smart Charging: Control charging rates based on grid load or tariffs.

6. Testing and Simulation

Use OCPP simulators for testing:

  • OpenOCPP → Simulates charge points and central systems.
  • OCPP-Tester → GUI-based simulator for testing OCPP communication.
  • EVSE Protocol Tester → Ideal for compliance testing.

🚀 7. Deployment and Scaling

  • Cloud Infrastructure: Deploy the central system on cloud platforms (AWS, Azure, GCP) for scalability.
  • Monitoring & Logging: Use tools like Prometheus, Grafana, or ELK stack to monitor charging activity.
  • Security: Ensure encrypted WebSocket connections and proper access controls.

Tech Stack Recommendations

  • Backend: Python (Django/FastAPI), Node.js (Express.js), Java (Spring Boot)
  • Database: PostgreSQL, MongoDB, or MySQL for storing charge point data
  • Frontend: React.js, Angular, or Vue.js for the admin panel
  • Cloud: AWS IoT or Azure IoT Hub for handling charge point connections

Sunstream embedded development services team has extensive experience in OCPP implementation. Talk to us today to understand how we can support you.