Study On Permanent Magnet Synchronous Motor Control In Electric Vehicle Application Based On The ADRC

Automobile industry is one of the largest and the most important industry all the world, and it is also the main support industry in almost every developed country. Because motor is the core of the electric vehicle power system, naturally the motor's control technology is the core technology in the field of electric vehicle. Motor used in electric vehicle consists of DC motor, induction motor, permanent magnet synchronous motor (PMSM), switched reluctance motor, and so on. Permanent magnet synchronous motors have numerous inherent advantages over other machines that are conventionally used for AC servo drives. High efficiency, high power density (kw/kg) and high torque to inertia ratio are some of the PMSM characteristics responsible for its wide utilization in different domains.Torque control is a key problem to be solved in PMSM speed regulating system. Coordinate transformation is a valid method to describe the torque characteristic of the PMSM. Using three phase static coordinate to two phase static coordinate, and two phase static coordinate to two phase rotational coordinate, the mathematic model can be represented as the model of DC motor, which has a similar torque characteristic as DC motor. Recently, there are many sensorless control algorithms for the control of PMSM, but most of them have the disadvantage of over-complicated and lack of robustness, then they can not be used widely. The active disturbance rejection strategy is independence of plant models. By using the extended state observer, the AC system has stronger robustness, which can overcome nonlinearity and coupling of the parameters of PMSM. Also, it can surmount parameters excursion caused by temperature change.Based on the corresponding research achievements abroad and domestic status of the technology, this paper addresses the study of PMSM control for electric vehicle on the aspect of active disturbance rejection strategy in sensorless control in PMSM and the corresponding hardware and software of the control system. By using the Simulink and Advisor software, the simulation is performed. And part experiment is done with a test vehicle. The specific work of this paper is as follows.First, based on the comprehensively deep research on the PMSM mathematic model, a novel speed and current regulator, namely the active disturbance rejection controller (ADRC), is proposed to achieve high performance PMSM drive by using the coordinate transformation technique. To make the speed and the d axis current in q axis current equation as disturbance, then the speed disturbance model and its structural diagram is set up based on the q axis current regulator to estimate the speed the PMSM. Compared to the traditional PI controller, the ADRC has better adaptability, low static and dynamic error, and good anti-disturbance ability. What's more, the speed estimation based on the ADRC is more accurate and applicable than the EKF method.In order to restrain the disturbances in PMSM servo drive caused by the changes of load, friction and rotor inertia, a speed control method based on ADRC techniques is presented in this dissertation, and the speed ADRC model is proposed. Based on ADRC, these parameter changes are regarded as disturbances of the related loop in PMSM servo system, which are estimated and then compensated by the ADRC. The MatLAB simulation results show that the servo system robust to those disturbances from 0r/min to 2000r/min, and the friction torque is compensated by the control method. The effect of dead-time in the speed tracking system has been restrained. Compared to the PI control method, the ADRC is also better in static and dynamic response and anti-disturbance ability with internal parameters changed, such as the increase of inertia, or external disturbance occurring.A new electric vehicle power system with lead acid battery and PMSM is also designed. By the simulation software Advisor, the battery, electromotor drive system and whole vehicle models are set up. The simulation results have shown that the vehicle can got a maxim speed 89.2 km/h and a acceleration 2.7 m/s~2, and the actual speed can track the speed of duty cycle. These proved that the design of the power system is practical and feasible.Lastly, part experiment is done based on the TMS320LF2407A DSP with a IPM power converter and using the space voltage vector PWM method. The experiment configure is composed of the interface circuit, the control loop circuit, the measurement circuit and the CAN communication module. The ADRC and the speed estimation algorithm are realized in the DSP. The idiographic software flow charts are given in this paper. The communication between the Host Computer and the DSP is realized through the CAN bus which can accomplish the instructions running, the parameters setting and the data capture function. The CAN receiving box and sending box of DSP is MB0X1 and MBOX4 respectively. The Host Computer can supervise the running condition of servo system on line. The experimental results obtained by the TDS-220 oscilloscope have further proved the speed estimation scheme proposed in this paper is accurate and have fast response in wide speed range. To summarize, this paper offers a powerful assist for further research and establishes the foundation for future analyses and development of PMSM control in electric vehicle.