Research On The Control Strategy Of The Driving Motor In The Shift Process Of Pure Electric Vehicle

As the energy and environmental problems restrict the development of the traditional automotive industry,the major automobile manufacturers are competing to develop new energy vehicles.In recent years,multi block becomes one of the development trend of new energy vehicles,PMSM+ AMT power system structure is gradually replacing the original PMSM + reducer,and compared with conventional vehicles,pure electric vehicles do not need to shift clutch,the driving motor control performance put forward higher requirements.In this thesis,the permanent magnet synchronous motor control of the pure electric vehicle equipped with two block AMT was studied.In this thesis,the PMSM-AMT drive control system,around the permanent magnet synchronous motor vector control,mainly carried out the following aspects of the study:Firstly,the mathematical model of PMSM in different coordinate systems was established.The vector control method of PMSM and the control strategy based on vector control method were introduced.Then,the basic principle of space voltage vector pulse width modulation algorithm was described and the simulation was carried out.Secondly,a speed controller with sliding mode variable structure control was proposed for the shortcomings of traditional PI controller in speed control.The effect of the two controllers was compared and analyzed.In order to solve the chattering of sliding mode variable structure control in this thesis,the fuzzy control was used to adjust the size of the switching gain in real time,and the designed fuzzy rules can weaken the chattering amplitude of the sliding mode control.Thirdly,in view of the slow response of speed regulation to load disturbance,a reduced load torque observer was designed to identify the load torque,and then feed-forward compensation was applied to the torque current.The designed reduced load torque observer had better identification accuracy,and the system had better anti-interference ability and better robustness after the current feed-forward compensation.Finally,the whole model was simulated by combining the whole vehicle model with complete shift process and several models of PMSM-AMT power system shift.The simulation results showed that the method can achieve the expected control effect and help to realize the gearshift.At the same time,through the experimental platform of PMSM-AMT power system,the experimental results showed that the control method and strategy used in the experiment were in good performance and the control was stable and accurate.