V2G Special Series (II): In-depth Analysis of the “Deterministic” V2G System Architecture

In the previous V2G topic series (1), “In the Year of Commercialization, China and Europe have taken different technological paths,” we explored the differences between V2G in China and Europe, as well as the macro background and commercial potential of vehicle network interaction. When the industry enters the ‘deep water zone’, the consistency of technological implementation becomes the core bottleneck for large-scale commercialization.

The essence of V2G is not charging and discharging, but turning cars into grid assets – in this issue, we will delve into the core technological elements that a mature V2G solution in Europe should possess.

In V2G (Vehicle to Grid) applications, communication protocols are crucial as they enable reliable, secure, and standardized data exchange between electric vehicles, charging stations, grid operators, and electric vehicle stakeholders. These protocols run through the entire communication chain and are used to achieve advanced communication between electric vehicles and charging stations for bidirectional power transmission.

ISO 15118-20 was released in 2022, laying the foundation for bidirectional charging and will be mandatory for all newly built public and private (Mode 3) charging stations starting from January 2027. ISO 15118-20 adds a detailed negotiation mechanism between electric vehicles and charging stations, including dynamic pricing and signals related to grid congestion.

ISO 15118-20 is the only legal evolution path for implementing V2G functionality. Compared to the traditional ISO 15118-2, the new standard has been given a core position, and its technological breakthroughs are mainly reflected in:

• ◉ Bidirectional power flow control (Dynamic Control): achieves finer P (active) and Q (reactive) regulation, supporting grid frequency response.
• ◉ Multi level security encryption: introduces stricter TLS 1.3 protocol and mutual certificate authentication to ensure the network security of vehicle assets when connected to the public power grid.
• ◉ Plug&Charge: In V2G scenarios, identity authentication is not only for billing, but also to establish the trust root of the vehicle as a “mobile energy storage unit”.

Engineering restructuring of three-tier architecture

The essence of V2G is not a hardware stack of “vehicle+pile”, but a reconstruction of distributed generation systems under the grid access system. A qualified grid connected V2G system must have three layers of collaborative capabilities: electrical layer (energy exchange): solving the high efficiency and low harmonic (THD<3%) injection of AC/DC bidirectional converters. Control layer (algorithm response): The focus is on the localized implementation of frequency droop control and fault ride through (FRT) algorithm. System layer (compliance certification): Addressing the overall consistency certification of the “vehicle cable pile” combination, which is a “mandatory ticket” for going global to Europe.

Building ‘deterministic’ control: three core algorithms

3、 Solution level application: Architecture design of V2G aggregation platform

A V2G solution with industry depth is not simply a “pile+vehicle” solution, but rather the construction of a closed-loop ecosystem of EV-EVSE-CPO-EMS.

4、 Deterministic V2G system architecture

The first engineering decision is: Where should the inverter be placed? This determines the certification process and technical responsibility boundary.

5、 Certification and Access

For decision-makers, whether a product can pass the review depends on their understanding of the standard system, including RfG (EU 2016/631), EN 50549-1, and EN 50549-10.

6、 Industry Insight: 2026 Turning Point Has Arrived

The competition of V2G is not a competition of power, but a competition of control accuracy and compliance depth. Prioritizing hardware platforms that support ISO 15118-20 and adopting a systems engineering approach is the true technological moat.