Success Story | EV Wireless Power Transfer Testing

The electrification, connectivity, and smartification of vehicles have become important indicators of the global automotive industry. Among them, wireless charging and fully automated driving (both safe and convenient) match the requirements of various Internet of Vehicles scenarios, enabling the full advancement of EV wireless power transfer (WPT). Recently, EV WPT has undergone some major breakthroughs: in May 2020, Mainland China officially released GB/T 38775; July of the same year saw the announcement of the UL 2750 Outline of Investigation for Wireless Power Transfer Equipment for Electric Vehicles; and it is estimated that in 2021, there will be EVs with standard WPT systems on the market.

Pain Reliever for Customers

Before introducing Chroma’s EV WPT test solution, this EV manufacturer could only semi-manually test the wireless charging quality. The fixture for the DUT misalignment position had to be adjusted by hand, and the fixture could not be altered under electricity - the input power needed to be turned off to stop the output load of the device. Additionally, manual adjustment may also easily cause alignment inaccuracies and affect the test results, which is inconvenient and timeconsuming. Before considering Chroma’s EV WPT test solution, this customer also evaluated other solutions. However, they could not support integration of an input source and output load, except providing a 3-axis WPT test platform without VA bracket or GA/VA alignment, and required manual control of the input source and output load. After comparing these test functions, the EV manufacturer firmly choose Chroma’s solution.

WPT Test Functions Comparison

With the Chroma 8000 Automated Test System as the core, Chroma’s EV WPT test system can configure a complete series of AC and DC power supplies and electronic loads. The test system covers the power requirements of WPT such as SAE J2954 and GB/T 38775. It can test the power effect of the wireless charger’s inlet, the stability and accuracy of the outlet, as well as the voltage and current limit protections. Equipped with a 2-in-1 power grid simulator and battery simulator, the EV WPT test system can also achieve G2V (Grid to Vehicle), V2G (Vehicle to Grid), and V2L (Vehicle to Load) WPT bidirectional charging and discharging simulation tests.

In the early stages of EV WPT semi-finished product development, input and output characteristics and offset efficiency tests must be repeated over and over. Chroma ATE provides test software dedicated to EV WPT, with features such as traceable viewing of real-time data monitoring records, 2D/3D chart generation, and a userfriendly operation interface.

Overall test time reduced by 96%. Test efficiency increased by 54 times

Upon Chroma’s assistance with EV WPT testing, the customer could reduce their number of testers from 2 to 1. The test time was shortened from 3 hours to 7 minutes, cutting down the overall test time by 96%. Moreover, the test efficiency was increased from 108 seconds per point to 2 seconds per point, enhancing test efficiency by 54 times.

In addition, the WPT test platform for simulation of EV WPT vehicle efficiency and parking misalignment offset can also be fitted with a multinational-patented, laserassisted center alignment fixture. It can so facilitate rapid alignment of wireless transmitters and receivers for WPT vehicle testing. Therefore, the test platform has been favored by multiple Japanese and Korean international automakers and China's indicative laboratories. The electric vehicle market continues to expand, and new innovative technologies are developing in ever diverse and rapid ways. Chroma actively continues to improve our accurate, reliable and unique test strategies based on successful and sustainable power supply technology.

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