ISO 15118-21:2025

Overview

ISO 15118-21:2025 - "Road vehicles - Vehicle to grid communication interface - Part 21" provides a formal conformance test plan (abstract test suite, ATS) for implementations of the vehicle-to-grid (V2G) communication interface defined in ISO 15118-20. Published jointly under the ISO/IEC framework, this document defines the network-layer and application-layer conformance tests for Electric Vehicle Communication Controllers (EVCC) and Supply-Equipment Communication Controllers (SECC) that are common across charging types (AC, DC, ACD, and WPT).

Key points:

• Defines an abstract test suite (ATS) to verify capabilities and behaviour of a system under test (SUT) implementing EVCC or SECC.
• Covers ISO/OSI layers 3–7 (network to application) and maps test architecture to test cases.
• Focuses strictly on conformance to ISO 15118-20 normative requirements; it is not a performance, robustness, or interoperability test.

Key Technical Topics and Requirements

• Capability vs behaviour testing: ATS contains capability tests (static conformance) and behaviour tests (dynamic conformance within the SUT’s declared capabilities).
• Test architecture and adapters: Describes test system (TS) architecture, platform adapter, and SUT adapters (including references to IEC 61851-1 and ISO 15118 family adapters).
• Protocol-level coverage: Test cases include SDP (service discovery), V2G Transport Protocol (V2GTP), and common V2G message flows for both EVCC and SECC.
• Test suite structure: Includes PICS (Protocol Implementation Conformance Statement) and PIXIT (Protocol Implementation Extra Information for Testing), test profiles, identifiers, verdict types, and timer/timeout handling.
• Abstract, tabular test cases: Test cases are specified in a descriptive tabular format and reference relevant external standards (IETF RFCs, W3C) only where required for conformance assessment - but do not extend the scope to those external standards unnecessarily.
• Limitations: Does not assess physical power flow, implementation internals, performance, robustness, or reliability; uses a black-box SUT testing paradigm.

Practical Applications and Users

Who uses ISO 15118-21:

• EV and EVSE (charging station) developers validating protocol conformance of EVCC/SECC stacks.
• Test labs and certification bodies developing automated conformance test suites and test tools.
• System integrators and quality engineers verifying network/application layer compliance before interoperability testing.
• Standards engineers and protocol implementers preparing PICS/PIXIT declarations and test plans.

Practical value:

• Establishes a consistent baseline to increase confidence that implementations conform to ISO 15118-20 protocol rules.
• Helps streamline downstream interoperability testing by verifying protocol behaviour across representative message flows and timers.

Related Standards

• ISO 15118-20 (normative reference for covered requirements)
• ISO 15118 series (other parts, e.g., -3, -5, -8, -9 related by cross-layer dependencies)
• IEC 61851-1 (charging interface adapter requirements)
• Relevant IETF RFCs and W3C Recommendations (referenced where required for conformance checks)

Keywords: ISO 15118-21, V2G, vehicle-to-grid, conformance test, EVCC, SECC, abstract test suite, ISO 15118-20, network layer, application layer, conformance testing.