Spatial-temporal Charging Pattern Analysis for Electric Taxi Grid Integration Study

Many cities in China are planning to adopt electric vehicles on a large scale. It is foreseeable that electric taxis will be an integral part of smart grids in the near future. However, due to the lack of historical data, the charging load of electric taxis is highly uncertain. This paper proposes a charging behavior simulation framework for electric taxi based on trajectory data of conventional internal combustion taxis currently in operation. The framework consists of battery discharging model, battery charging model and charging event decision model. Under this framework, dynamics of state of charge can be simulated and rational charging decisions can be derived. A case study is performed using GPS data of a taxi fleet in Shanghai, China. Spatial and temporal distribution of charging load is obtained and the effect of charging price is examined.