GB/T 38775.2-2020

Electric vehicle wireless power transfer—Part 2: Communication protocols between on-board charger and wireless power transfer device (English Version)

Standard No.

GB/T 38775.2-2020

Language

Chinese, Available in English version

Release Date

2020

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Latest

GB/T 38775.2-2020

Scope

This part of GB/T38775 specifies the communication protocol for wireless charging control between the ground communication control unit (CSU) and the in-vehicle communication control unit (IVU) of the static wireless charging system of electric vehicles; it also specifies the wireless charging control management system (WCCMS) Communication protocol involved in wireless charging control. This section applies to the management and control between the ground communication control unit (CSU) and the control management system (WCCMS), and between the in-vehicle communication control unit (IVU) and the ground communication control unit (CSU).

Introduction

Analysis of the core architecture of the standard

The wireless charging system defined by the standard adopts a layered architecture:

• Ground system: includes WCCMS (control management system), CSU (ground communication unit), PTC (power transmission controller) and other equipment
• Vehicle system: includes IVU (in-vehicle communication unit), PPC (power receiving controller) and other components

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Communication mode	Participating unit	Typical application scenario
Mode A	CSU↔IVU	Private charging pile, basic communication
Mode B	WCCMS↔CSU↔IVU	Public charging station, remote management

Key Technical Parameters

Communication Interface Specifications

• CI interface: IEEE 802.11 physical layer protocol is adopted between CSU and IVU
• Keep-alive mechanism: The default timeout detection is 1 minute to ensure connection reliability

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Safety Control Requirements

The system must implement a triple protection mechanism:

1. Two-way authentication of equipment (digital signature + random number challenge)
2. Encrypted transmission of communication data
3. Real-time fault monitoring (including 21 types of vehicle system faults and 15 types of ground system fault codes)

Typical communication flow

Charging startup process (mode B)

1. IVU registration→CSU→WCCMS
2. Interoperability detection (coil matching verification)
3. WCCMS issues charging instructions
4. PTC activates energy transmission

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Exception handling mechanism

Fault type	Handling method	Response time
Communication interruption	Automatically stop charging + status reporting	≤60s
Liveness detection	Immediate termination + fault code 0x21/0x02	Real-time

Implementation suggestions

Key points for device development

• CSU should support simultaneous management of multiple PTC devices (the maximum number needs to be configured according to the actual scenario)
• IVU needs to integrate vehicle driving mode detection (OFF/ACC/ON/LOCK status)

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Test and verification requirements

It is recommended to verify in stages:

1. Protocol consistency test (message format/state machine)
2. Interoperability test (networking of devices from different manufacturers)
3. Security stress test (simulating malicious attack scenarios)

GB/T 38775.2-2020 Referenced Document

• GB/T 38775.1-2020 Electric vehicle wireless power transfer—Part 1:General requirements
• GB/T 38775.3-2020 Electric vehicle wireless power transfer—Part 3: Specific requirements

GB/T 38775.2-2020 history

• 2020 GB/T 38775.2-2020 Electric vehicle wireless power transfer—Part 2: Communication protocols between on-board charger and wireless power transfer device

GB/T 38775.2-2020 -All Parts