| Permanent magnet synchronous motors have no exciting current in the rotor, and are high efficiency and power density. But motion control of permanent magnet synchronous motors requires accurate position and velocity signals to accomplish field orientation. In conventional motion control systems, optical encoders or rotary transformer are used for this purpose. However, these additional sensors increase the costs of the system and reduce the reliability. With this background, the research based on the abolishment of these sensors to increase the reliability and decrease the costs is becoming popular.The mathematical model of the permanent magnet synchronous motor is built firstly, the theory of vector control on permanent magnet synchronous motor is studied further deeply. Aiming at the shortcomings of conventional vector control, a novel vector control system based on space-voltage vector pulse width modulation (SVPWM) is proposed in this dissertation. The SVPWM can help the inverter to realize continuous voltage vector modulation, decrease the current harmonic component, and restrain the torque ripples, and the DC bus voltage utilization can be improved and the speed range of the system can be expanded.The software and hardware platform of vector control system based on the DSP TMS320LF2407A is designed. The reasonable design can make the servo system work smoothly at the lowest speed and have a nicer speed regulation. In the part of hardware, the circuits design and debug are completed, including: current detector circuit, velocity detector circuit, FPGA display design, driving circuit and protecting circuit etc. As for software, the control algorithm of PMSM was implemented by DSP program. It adopted the id = 0 vector control method to realize the decoupling control of PMSM. The general PI control method was used in the speed and current loop, and SVPWM modulation was used in the inverter. The motor's current analog signals and speed signal are transacted into digital signal firstly. The DSP programs are compiled, such as the main program of the system, the initialization program and the interrupt process subprogram. The program have done debugged largely base on the hardware platform.We have done a lot of studies of experiments and system simulation which is based on sensorless Vector Control system. Experiment and simulation waveforms are analyzed deeply. The result indicates that the system has many fine characteristics such as fast response, run after giving speed quickly, smoothly at the lowest speed and fine antijamming ability, can satisfy the demand of driver design . |
