Analysis of Brake Characteristics of Light-Duty Vehicles in Typical City in China

In November 2022, the European Union released the draft of the seventh stage emission regulations of light-duty vehicle. For the first time, non-exhaust emissions from light-duty vehicles were included in the regulation. In order to more accurately measure brake particle emissions, the European Union developed WLTC-Brake cycle based on the WLTC database for brake particle emissions measurement. This cycle unified the test conditions and avoided differences in test results caused by the lack of unified test cycle. In order to verify whether WL TC-Brake cycle is suitable for China's real roads, this paper collected real road driving data of 100 pure electric passenger cars in ten typical cities in China and analyzed the brake characteristics of the collected data. Results shown that China's real road brake characteristics are lower than those of WL TC-Brake cycle in terms of initial brake speed, average brake deceleration, brake duration, and brake interval. Therefore, it is necessary to develop a brake cycle that conforms to China's real road conditions to evaluate China's real road brake particle emission levels.