AC PLC – Why do Europe and the United States need AC charging piles that comply with the ISO 15118 standard?

In standard AC charging stations in Europe and the United States, the charging status of the EVSE (charging station) is typically controlled by an onboard charger controller (OBC). However, the application of AC PLC (power line communication) technology establishes a highly efficient communication method between the charging station and the electric vehicle. During an AC charging session, PLC manages the charging process, including handshake protocol, charging initiation, charging status monitoring, billing, and charging termination. These processes interact between the electric vehicle and the charging station through PLC communication, ensuring efficient charging and enabling payment negotiation.

PLC standards and protocols described in ISO 15118-3 and DIN 70121 specify PSD limits for HomePlug Green PHY PLC signal injection on the control pilot line used for vehicle charging. HomePlug Green PHY is the PLC signal standard used in vehicle charging specified in ISO 15118. DIN 70121: This is an early German standard used to regulate DC communication standards between electric vehicles and charging stations. However, it lacks transport layer security (Transport Layer Security) during the charging communication process. ISO 15118: Developed based on DIN 70121, it is used to regulate the safe charging requirements of AC/DC between electric vehicles and charging stations, with the goal of becoming an international standard for global communication protocols. SAE standard: Mainly used in North America, it is also developed based on DIN 70121 and is used to regulate the communication standard for the interface between electric vehicles and charging stations.

Key Features of AC PLC:

Low Power Consumption: PLC is specifically engineered for low-power applications, making it the optimal choice for smart charging and smart grid systems. This technology operates throughout the entire charging session without excessive energy expenditure.

High-Speed Data Transmission: Based on the HomePlug Green PHY standard, it supports data transfer rates of up to 1 Gbps. This capability is vital for applications requiring rapid data exchange, such as reading vehicle-side State of Charge (SOC) data.

Time Synchronisation: AC PLC enables precise time synchronisation, essential for smart charging and smart grid systems requiring accurate timing control.

Compatibility with ISO 15118-2/20: AC PLC serves as the key communication protocol for AC charging in electric vehicles. This facilitates communication between EVs and charging stations (EVSEs), supporting advanced charging functions such as demand response, remote control, and future smart charging features like PNC (Power Normalisation Control) and V2G (Vehicle-to-Grid) capabilities for smart grids.

Advantages of AC PLC implementation for European and American charging networks:

1. Enhanced energy efficiency and utilisation AC PLC charging points increase the proportion of smart charging points among existing standard AC chargers (over 85%) without requiring capacity expansion. This improves energy distribution efficiency at target charging stations and reduces energy wastage. Through intelligent control, AC PLC chargers can automatically adjust charging power based on grid load and electricity price fluctuations, achieving more efficient energy utilisation.

2. Strengthening grid interconnectivity: PLC technology enables better integration of European and American AC charging points with smart grid systems, facilitating cross-border power interconnection. This promotes complementary use of clean energy across broader geographical areas, enhancing grid stability and reliability. Particularly in Europe, such interconnectivity optimises the allocation of clean energy sources, such as northern wind power and southern solar energy.

3. Supporting smart grid development AC PLC charging points function as integral components within smart grid ecosystems. Through PLC technology, charging stations can collect and analyse real-time charging data, enabling energy management, optimised charging strategies, and enhanced user services. Additionally, PLC facilitates remote monitoring and control, improving operational efficiency at charging stations.

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Post time: Sep-13-2025