The electric drive system is one of the key technologies for electric vehicles. First, the energy flow of an electric vehicle is analyzed in the driving, braking, and charging working states. After that, a drive topology that can achieve 3 working states is proposed based on the driving characteristics of a switched reluctance machine. In the driving state, the boost mode of a front-end converter is used to achieve different operating conditions, including low speed with a light load or high speed with a heavy load. In the braking state, the front-end converter is used to implement smooth switching between initial excitation and braking energy feedback. In the charging state, a new power factor correction circuit is proposed, and the motor windings and power converter constitute the onboard charger, whose power factor is correctable. According to the proposed drive topology, the control strategies for 3 working states are put forward. Finally, an experimental platform is built to verify the correctness of the control strategies as well as the flexibility of the whole system.
CHENG, HE; CHEN, HAO; MA, LEI; and YU, GUOJUN
"Research on switched reluctance machine drive topology and control strategies for electric vehicles,"
Turkish Journal of Electrical Engineering and Computer Sciences: Vol. 24:
2, Article 19.
Available at: https://journals.tubitak.gov.tr/elektrik/vol24/iss2/19