Effects of Payloads on Non-exhaust PM Emissions from A Hybrid Electric Vehicle during A Braking Sequence

Abstract

Vehicles equipped with internal combustion engines are known as important sources of particulate matter (PM) emissions. Many countries are aware of this issue. They are keen in converting internal combustion engine vehicles to electric vehicles (EV) to reduce PM problems. However, various past research works claimed that EV also emit PM like conventional vehicles due to their non-exhaust emissions from brake wear, tyre wear, road surface wear, and resuspension of road dust. In addition, strong evidence showed that there was indeed a positive correlation between the weight of vehicle and amounts of non-exhaust PM emissions. The current study is aimed to measure on-road non-exhaust PM emissions from a hybrid electric vehicle during a braking sequence at various payloads. An onboard PM measuring device is attached nearby the center cap bore of the left front wheel on the tested hybrid electric vehicle. PM1, PM2.5, and PM10 measurements are monitored during braking sequences in the electrified vehicle mode. The increase payloads that affect tendency of non-exhaust PM emissions are observed. The PM emission pattern during braking sequence is captured by the current PM measuring setup as seen in the literature. Based on this experiment, the additional payloads of 60-70 kg increase the amount of non-exhaust PM2.5 and PM10 emissions almost 25%. The effects of increasing payloads on PM2.5 and PM10 emissions can be clearly observed as a linear relationship. However, for PM1 emissions, when increasing payloads, a certain cut point is observed at the payload of 130 kg. Adding payloads more than 130 kg do not affect the amount of PM1 emissions.