Development of electric machine duty cycles for parallel hybrid electric Beijing city bus based on Markov chain

The paper represents an integrated and detailed procedure of developing representative duty cycles for evaluating the electric machine installed on parallel hybrid electric buses. First, real world bus route speed data were collected from the all-electric bus running on the No. 121 route in Beijing. Optimal load cycles of the electric machine are obtained from dynamic programming algorithm. Then, Markov chain and subsequent statistical analysis are used to construct representative load cycles for the electric components from the extracted information from the optimal cycles. Finally, the representative duty cycles were constructed for the motor performance and reliability testing procedures.