Hybrid Sliding-Mode Control Of Double Mode EV Based On Sensorless BLDCM

The controlling system requires high performance on robustness and adaptability as factors of variable driving mode, complex working environment and vulnerability on interference exist in electric vehicles (EV). As widely use of brushless DC motor (BLDCM) in EV, controlling system with high performance for BLDCM has become the focus on recently research.In order to realize the accurate commutation control, position sensor is needed to get position feedback in traditional EV used BLDCM. As the position sensor will cause reduced working life, limitation of working environment and other defects, controlling strategy of sensorless BLDCM has gained a lot attention of researchers.After deep research on controlling system of EV, this thesis presents results of study as follows:(1) The theory of EKF application on nonlinear system is studied in this thesis. And the mathematical model of BLDCM is discretized to build the estimation principle of EKF on BLDCM, and a M-estimation principle is proposed to improve the robust of EKF. Then this strategy is verified and researched through simulation.(2) This thesis presents a hybrid high-order terminal sliding-mode control strategy with robustness and efficient performance for the EV using BLDCM under normal driving and energy regeneration mode. Mathematical model with perturbation is built under normal driving and energy regeneration mode, and a small-signal analysis is done. Then the nonlinear terminal and high-order sliding-mode control are combined to devise the hybrid terminal sliding-mode control strategy (HTSM), which is designed separately for two different driving modes.(3) The whole controlling system and experimental platform of EV is designed in this thesis, which is composed of hardware and software parts. And hardware system contains TMS320F DSP and CM200DY-12H and other functional modules. Software system consists of HTSM controlling and EKF estimation algorithm. Results show that the proposed control solution produces wide system suitability and has a good performance in convergence time and chattering restraint.