GB/T 38775.3-2020Electric vehicle wireless power transfer—Part 3: Specific requirements (English PDF)

3.1 Stationary Magnetic Field Wireless Power Transfer; MF-WPT

Stationary magnetic field wireless power transfer refers to a power transfer mode which uses magnetic field as a medium to transfer wireless power from a power source to a power load through magnetic coupling; the physical position of the power source and the power load is in the stationary state.

3.2 System Frequency

System frequency refers to the frequency range of wireless power transfer system for power transmission.

3.3 Nominal Frequency

Nominal frequency refers to the operating frequency of system design. In terms of systems with an adjustable frequency, when the primary device and the secondary device are aligned, and all components are stably operating with the designed parameters, the system will operate at the nominal frequency.

3.4 Secondary Device Ground Clearance

Secondary device ground clearance refers to the minimum vertical distance between the lower surface of the secondary device and the ground.

3.5 Automatic Charging Mode

During the charging process, the wireless power transfer system, in accordance with the data provided by the electric vehicle, dynamically adjusts the charging parameters and executes corresponding operations to complete the charging process.

3.6 Wireless Charging Control and Management System; WCCMS

Wireless charging control and management system is responsible for charging coordination control, operation and maintenance monitoring management, business operation management and system management functions of one of multiple electric vehicle wireless power transfer systems.

4.1 By Magnetic Pole

In accordance with magnetic pole, the classification of MF-WPT is shown in Figure 1.

4.2 By Resonance Compensation Topology

The resonance circuit of MF-WPT system is shown in Figure 2. The primary device and the secondary device may adopt these resonance topologies.

4.3 By Input Power Level

The classification by input power level shall comply with the stipulations of 6.2 in GB/T 38775.1-2020.

4.4 By Service Environment

The classification by service environment shall comply with the stipulations of 6.3 in GB/T 38775.1-2020.

4.5 By Installation Mode

The classification by installation mode shall comply with the stipulations of 5.4.1 in GB/T 38775.1-2020.

5.1 System Efficiency

At the rated operating point system efficiency shall be not lower than 85%. When the system is output at the rated power, under the condition of all allowable deviations in the vertical and the horizontal directions, system efficiency shall be not lower than 80%.

5.2 System Frequency

System frequency of MF-WPT system shall satisfy the requirements in Table 1.

5.3 Mechanical Air Gap

Mechanical air gap of primary and secondary devices of MF-WPT system shall satisfy the requirements in Table 2.

5.4 Ground Clearance

Ground clearance of secondary devices of MF-WPT system shall satisfy the requirements in Table 3.

5.5 Offset Range

Within the offset range shown in Table 4, primary and secondary devices of MF-WPT system shall satisfy the requirements of 7.6 in GB/T 38775.1-2020.

5.6 System Structure MF-WPT

system structure shall take Appendix A of GB/T 38775.1-2020 as a reference.

5.7 Primary Devices

5.7.1 Installation mode

Installation mode of primary devices is shown in the stipulations of 5.4 in GB/T 38775.1-2020.

5.7.2 Installation location

Installation location of coil of primary devices shall take A.1 of Appendix A as a reference.

5.8 System Functions

5.8.1 Charging mode

MF-WPT system shall be equipped with the mode of automatic charging.

5.8.2 Standby awaken

When MF-WPT system is in standby state, it shall be able to be awaken by the off-board devices.

5.8.3 Parameter detection

In accordance with information exchanged during the initialization stage, detect interoperability parameters between the primary devices and the secondary devices,

5.8.6 Protection of living body

The off-board devices of MF-WPT system should have a function of living body protection, which can judge whether a living body exists in Protection Area 1 and 2 in GB/T 38775.4-2020. If a living body is detected, then, MF-WPT system sends out a warning, and stops charging, or, does not initiate charging.

5.8.7 Safety interlocking

The state of being charged and the vehicle's driving mode shall be in an interlocking relationship.

5.8.8 Man-machine interaction function

MF-WPT system shall display the following information or state.

5.8.9 Abnormality protection

The off-board devices and on-board devices of MF-WPT system shall all be equipped with a function of abnormality protection. See the specific requirements below.

6.1 Command and Control Communication

MF-WPT system shall be equipped with the capability of wireless communication between the off-board devices and the on-board devices.

6.2 High-level Communication

In high-level communication, MF-WPT system shall be equipped with the capability of wireless communication among the off-board devices, the on-board devices and the wireless charging control and management system.

7.1 System Efficiency MF-WPT

system efficiency shall comply with the stipulations of 5.1. This Clause is applicable to power level. MF-WPT1, MF-WPT2 and MF-WPT3.

7.2 Power Factor

Under the rated input and rated output conditions, MF-WPT system's input power factor shall be not lower than 0.98.

7.3 Input Harmonic Current

Merely applicable to the following categories of wireless charging devices.

7.4 Electromagnetic Environment Limits

Electromagnetic environment limits of MF-WPT system shall satisfy the requirements of Chapter 5 in GB/T 38775.4-2020.

7.5 Protection against Electric Shock

The requirements for protection against electric shock of MF-WPT system shall comply with the stipulations of 10.2 in GB/T 38775.1-2020.

7.6 Dielectric Strength Characteristics

The requirements for dielectric strength characteristics of MF-WPT system shall comply with the stipulations of 10.2.3 and 10.2.4 in GB/T 38775.1-2020.

7.7 Overcurrent Protection and Short-circuit Protection

The overcurrent protection and short-circuit protection function of MF-WPT system shall satisfy the requirements of 10.3 in GB/T 38775.1-2020.

7.8 Temperature Rise and Overheating Prevention

Temperature rise and overheating protection function of MF-WPT system shall satisfy the requirements of 10.4 in GB/T 38775.1-2020.

8.1 Test Conditions and Environment

8.1.1 Test system

A schematic diagram of wireless charging test system is shown in Figure 3.

8.1.2 Test platform

Test platform can accommodate.

8.1.3 Ambient conditions

The test shall be conducted under the following ambient conditions.

8.1.4 Power source conditions

During the test, the power source conditions are as follows. […]

8.1.5 Test instrument requirements

Unless it is otherwise stipulated, the precision of the instruments used in the test shall satisfy the following requirements. […]

8.1.6 Test load

The load described in the test shall select resistance load or electronic load.

8.2 System Efficiency

8.2.1 System efficiency test of MF-WPT system without offset

Under the rated input conditions, the system efficiency test of MF-WPT system under the conditions of no offset under different power sections and different mechanical air gaps is shown in Table B.1 in Appendix B.

8.2.2 System efficiency test of MF-WPT system with offset

The system efficiency test points are shown in Figure 4.

The requirements and recording of system efficiency test points with offset are shown in Table B.2.

8.2.3 System efficiency test of MF-WPT system with Deflection

Test the system efficiency under the condition that the secondary coil deflects around the Z axis. During the test, the deflection angle is 10°; the selection of test points is shown in 8.2.2.

8.3 Power Factor

Under the rated input conditions, the power factor test of MF-WPT system under the conditions of no offset under different power sections and different mechanical air gaps is shown in Table B.4.

8.4 Harmonic Current

Under the rated input and rated output conditions, the harmonic current limit test of MF-WPT system under the conditions of nominal air gap and no offset is shown in Table B.6.

8.5 Electromagnetic Environment Limits

The test method of electromagnetic environment limits of MF-WPT system shall comply with the requirements of Chapter 6 in GB/T 38775.4-2020.

8.6 Protection against Electric Shock

8.6.2 IP level of enclosure

The IP protection level of the enclosure of charging cabinet and cold-source cabinet shall comply with the requirements of 10.2.5.2 in GB/T 38775.1-2020. The test method shall comply with the stipulations of Chapter 13 and Chapter 14 in GB/T 4208-2017.

The IP protection level of the various modules of the on-board devices shall comply with the requirements of 10.2.5.4 in GB/T 38775.1-2020. The test method shall comply with the stipulations of Chapter 13 and Chapter 14 in GB/T 4208-2017.

8.6.3 IP level of primary devices

The IP protection level of primary devices shall comply with the requirements of 10.2.5.3 in GB/T 38775.1-2020. The test method shall comply with the stipulations of Chapter 13 and Chapter 14 in GB/T 4208-2017.

8.6.4 IP level of secondary devices

The IP protection level of secondary devices shall comply with the requirements of 10.2.5.4 in GB/T 38775.1-2020. The test method shall comply with the stipulations of Chapter 13 and Chapter 14 in GB/T 4208-2017. […]