A Wi-Sun Network-Based Electric Vehicle Charging Station Using Open Charge Point Protocol (OCPP)

Key Technological Concepts and Protocols:

• Wi-SUN (Wireless Smart Utility Network):
  • A mesh network communication protocol operating in the sub-GHz ISM band (865-868 MHz in India) based on IEEE 802.11 standards.
  • Enables devices (such as EV chargers) to connect to the internet via a mesh of nodes, ensuring robust and wide-area connectivity without relying on Wi-Fi or LTE.
  • Deployed extensively across the Tri Hyderabad campus with about 60 nodes integrated into street lights, providing continuous cloud connectivity for devices.
• Open Charge Point Protocol (OCPP):
  • An open international protocol used for communication between EV charging stations and central management systems.
  • Handles authentication, transaction management, and charging control messages between the EV charger and backend servers.
• OneM2M Platform:
  • A middleware layer recognized as the de facto standard by India’s Smart City Mission for smart city infrastructure.
  • Acts as a data lake and structured database for managing and querying data from various city sensors and devices, including EV chargers.
  • Supports user authentication, wallet management (for payments), and transaction logging in a structured tree format separating users and chargers.

Product Features and System Architecture:

• The EV charging station integrates all three protocols:
  • Wi-SUN for communication,
  • OCPP for charge point messaging and authentication,
  • OneM2M for middleware services like user management and data storage.
• Hardware includes a Raspberry Pi microcontroller for computation and control, a Silicon Labs Wi-SUN module for communication, a power meter for consumption tracking, a relay for switching, and a user interface display.
• The system operates like an ATM: users authenticate via RFID, check wallet balance, input the desired charging amount, and the system manages charging sessions accordingly.
• Safety features include an emergency stop switch and power line tapping for powering the electronics.
• The solution currently supports 16 Amp chargers primarily for electric bikes.

Innovations and Advantages:

• The combination of Wi-SUN, OCPP, and OneM2M provides an interoperable and scalable EV charging solution suitable for smart city deployments.
• The mesh network ensures connectivity without dependency on cellular or Wi-Fi infrastructure.
• OneM2M’s structured data model allows seamless user and charger management, enabling users to charge at any station in the network, akin to using any ATM with a single card.
• The entire software stack and middleware have been developed in-house and made open source by the Tri Hyderabad team.

Deployment and Use Case:

• The system is deployed at the Tri Hyderabad campus as part of a smart campus initiative with extensive sensor and IoT deployments.
• The EV charger prototype is demonstrated with an electric bike.

Main Speaker:

• Afab Husin, Faculty Member at Tri Hyderabad, presenting the research and development of this Wi-SUN network-based EV charging station using OCPP and OneM2M middleware.

Summary of content: The video is a technical presentation and tutorial on an innovative EV charging station solution integrating Wi-SUN mesh networking, OCPP for charging protocol, and OneM2M middleware for smart city data management. It highlights the architecture, protocols, hardware design, user flow, and deployment in a smart campus environment, emphasizing interoperability and scalability for future smart city applications.