GB/T 38775.6-2021Electric vehicle wireless power transfer—Part 6: Interoperability requirements and testing—Gground side (English PDF)

3.1 Interoperability

Interoperability refers to the capability of off-board supply device and on-board supply device of the same or different models and versions of wireless power transfer system in implementing the interconnection of electric vehicle wireless power transfer through information interaction and process control.

3.2 Primary Coil

Primary coil refers to a coil formed by one or multi-turn winding and capable of generating an electromagnetic field.

3.3 Secondary Coil

Secondary coil refers to a coil formed by one or multi-turn winding and capable of receiving electromagnetic field.

3.4 Off-board Reference Device

Off-board reference device refers to a test device that forms the MF-WPT system with the on-board supply device to be tested.

3.5 On-board Reference Device

On-board reference device refers to a test device that forms the MF-WPT system with the off-board supply device to be tested.

3.6 Positioning Detection; PD

Positioning detection is actuated when the primary device and the secondary device are separated by a certain distance to realize the detection of the relative position of the primary device and the secondary device. It is used to guide the process of aligning the secondary coil and the primary coil.

4.1 Symbols

The following symbols are applicable to this document.

ACCGA-VA. the detection accuracy of the relative position of the primary device and the secondary device, which is composed of the X-axis detection accuracy and the Y-axis detection accuracy.

4.2 Abbreviations

The following abbreviations are applicable to this document.

CN. Compensation Network CSU. Communication Service Unit EMF. Electric and Magnetic Field INV. Inverter IVU. In-Vehicle Unit

5.1 System architecture

Figure 1 shows the system architecture and components of the MF-WPT system.

5.2 Classification

5.2.1 Input power level classification

The input power level classification of the MF-WPT system shall comply with the requirements of power level in 6.2 of GB/T 38775.1-2020. This document merely specifies the interoperability of MF-WPT1, MF-WPT2 and MF-WPT3 systems.

5.2.2 Classification of off-board supply device

The off-board supply device may be divided into Type-A and Type-B, in which.

5.2.3 Classification of ground clearance

For the MF-WPT system composed of Type-A off-board supply device and on-board reference device, the classification of ground clearance supported by the off-board supply device shall satisfy the ground clearance range of the secondary device that it can support, as it is shown in Table 1.

6.1 Requirements for Off-board Reference Device

The off-board reference device shall be designed in accordance with the requirements of Appendix A. The interoperability of the off-board reference device and the on-board supply device with different ground clearances shall satisfy the requirements of Table 2.

6.2 Requirements for Preparation Stage before Charging

The requirements for the preparation stage before charging of Type-A off-board supply device shall be tested in accordance with the test methods specified in 8.1.

The safety test results of Type-A off-board supply device shall comply with the safety requirements of Chapter 10 in GB/T 38775.1-2020, vehicle rolling in 12.3, living body protection in 5.8.6 of GB/T 38775.3-2020, and protection areas and limit compliance requirements in Chapter 4, and limits in Chapter 5 of GB/T 38775.4-2020.

6.3 Requirements for Charging start-up Stage

When Type-A off-board supply device and on-board reference device compose MF- WPT system, the following conditions must be satisfied before it is allowed to enter the charging state.

6.4 Requirements for Charging Transmission Stage

6.4.1 General requirements

The manufacturer of Type-A off-board supply device shall provide the following information.

6.4.2 Requirements for power transmission control loop

For the MF-WPT system composed of Type-A off-board supply device and on-board reference device, the power transmission control loop shall adopt the circuit shown in Figure 2.

6.4.3 Requirements for output power

The output power test of the MF-WPT system composed of Type-A off-board supply device and on-board reference device shall be carried out in accordance with the test method in 8.3. During the test, the on-board reference device shall support the off-board supply device to start with a power of not lower than 0.25 kW/s.

In addition, the rated output power of the MF-WPT system composed of Type-A off-board supply device and on-board reference device shall satisfy the stipulations of

6.4.4 Requirements for system efficiency

MF-WPT system efficiency refers to the ratio of the output power of on-board reference device (module 25 in Figure 1) to the input power of off-board supply device (module 15 in Figure 1); the test points shall be selected in accordance with the stipulations of 5.2 in GB/T 38775.1-2020.

The efficiency of the MF-WPT system composed of Type-A off-board supply device and on-board reference device shall be tested in accordance with the test method specified in 8.3.2. During the efficiency test, the charging voltage range (from the

6.5 Requirements for Charging Stop Stage

Under the following circumstances, the off-board supply device shall stop charging.

a) When the on-board reference device sends a request to stop charging;

b) When the off-board supply device sends a request to stop charging;

c) When the communication between CSU and IVU is disconnected;

d) When a foreign object is detected;

e) When a living body is detected;

f) When a failure is detected.

The off-board supply device shall retain a mode of allowing the user to actively stop charging, for example, the installation of a stop charging button on the off-board supply device.

7.1 Frequency Setting

The working frequency of the off-board supply device shall be set in accordance with the nominal frequency specified in Table 5.The working frequency of the MF-WPT

7.2 Setting of Alignment Tolerance Area and Alignment Point

The alignment tolerance area of Type-A off-board supply device shall be provided by the device manufacturer, and the provided offset range shall at least satisfy the range required by Table 6.

7.3 Selection of Output Voltage Measurement Point

During the interoperability test, for the test load with a charging voltage range of Uout-min ~ Uout-max, the output voltage test point of the on-board reference device of MF-WPT system shall at least include.

7.4 Layout of Test Device

During the interoperability test, the material or component of simulated chassis shall be adopted to replace the vehicle chassis; the on-board reference device shall be installed on the material or component of the simulated chassis. The material or component of the simulated chassis includes two parts. shielding component and steel plate. The shielding component may use the shielding plate shown in Figure 4, or it may also be provided by the device manufacturer. If the shielding component is provided by the device manufacturer, it shall be indicated in the test report. In the interoperability test, the off-board supply device shall include all components, for example, the enclosure. The test load should use an electronic load. The on-board reference device, shielding layer and simulated vehicle chassis shall be closely attached.

8.1 Test of Pre-charging Preparation Stage

When the MF-WPT system is composed of Type-A off-board supply device and on-board reference device, the safety test shall be carried out in accordance with the safety requirements in Chapter 10 and the stipulations of vehicle rolling in 12.3 of GB/T Ground (concrete or asphalt) 38775.1-2020.

8.2 Test of Charging Start-up Stage

8.2.1 Test of foreign object detection

8.2.1.1 General rules

The test object of foreign object detection shall comply with the stipulations of Table 7 in GB/T 38775.3-2020.

8.2.1.2 Test area

The test area of foreign object detection shall include the area shown in Figure 6 of GB/T 38775.3-2020.

8.2.2 Test of living body protection

8.2.2.1 General rules

In the test of living body protection, the primary coil and the secondary coil shall be in the maximum offset state under the maximum ground clearance. For the on-board reference device of the corresponding power level, it shall be ensured that the MF- WPT system is working at the maximum output power level.

8.3 Test of Charging Transmission Stage

8.3.2 Test procedures of system output power and system efficiency

For the MF-WPT system with a system output voltage range of Uout-min ~ Uout-max, the test procedures of system output power and system efficiency shall be.