An Analysis of the Carbon Emission of PHEV Based on Travelling Pattern in China Mega Cities

The high thermal power ratio in China’s power grid and the complexity of PHEV driven energy make the study of PHEV’s carbon emissions complicated. The existing researches lack the analysis based on the actual PHEV driving data, which leads to inaccurate calculation results. This paper aims to accurately assess the carbon emission levels of PHEVs in typical mega cities in China and to analyze the potential for carbon reduction under different driving patterns. This study investigated the carbon emission levels of PHEV vehicles with different driving range and charging frequency from the perspective of the automotive energy production and use processes. Study is based on the characteristics of Shanghai’s 50 PHEV70 and cumulative mileage of 130,000 km, and the carbon emission levels of PHEV, HEV and ICE are compared. As for the method, distribution of driving range and battery state of charge (SOC) was achieved by cleaning and cutting the PHEV monitoring big data. Based on this, electric drive ratio was calculated. Combining the carbon emission levels of electricity and gasoline in the energy production to the use, the carbon emission levels of different driving frequency and electric vehicle driven mileage and oil-driven mileage at different charging frequencies can be calculated during the energy production of PHEV vehicles of different driving ranges. Carbon emissions of PHEV vehicles with different driving ranges at different charging frequencies can be derived combining the carbon emissions of electricity and gasoline from energy production to use. The result shows that the average carbon emissions of PHEV70 vehicles in Shanghai are 155 g/km, including 71 g/km for electric distance and 84 g/km fuel distance, which is 5% and 16% lower than those of HEV and ICE respectively. PHEV carbon emissions decreases with the increase of charging frequency and driving range, the carbon emission of charging more than once a day can be improved by 4.0% over the average charging frequency. Considering carbon emission and marginal revenue comprehensively, the optimal driving range of PHEV is 100 km, which is 4% lower than that of PHEV50. Therefore, increasing the PHEV driving range to 100 km is possible to achieve emission reduction level similar to that provided by the carbon effect of increasing the charging frequency.