Research On Sensorless Vector Control Technology Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor has many excellent characteristics,such as high power density,fast dynamic response,high efficiency and so on.It has been widely used in the electric drive field.Space-vector control method is capable to obtain excellent running performance,but it needs installing position sensor,which inevitably increase the complexity and cost of the system.In some applications,it is difficult to use the position sensors.So the sensorless vector control strategy of PMSM is studied in this thesis.In this thesis,the principle and defects of the open loop I/f control were studied.In order to achieve full speed range running,proposed an improved efficient I/f control strategy,which includes two aspects: one is adjusting the speed of current vector according to the disturbance component of the active power and the other is adjusting the amplitude of current vector according to the angle ? between current vector and q-axis,so as to increase the damping torque and improve the efficiency of the system.Also,using algorithm switching to achieve full speed range sensorless control is studied in this thesis.Analyzed the initial rotor position estimation,sensorless control method in low and high speed range and algorithm switching method.At last,the overall control scheme of PMSM sensorless drive is analyzed and designed.At last,the software and hardware of the PMSM sensorless control system which is based on Renesas DSP chip(RX62T)were designed.Two full speed range sensorless control scheme was evaluated by experiments.The experimental results illustrate the good anti-interference ability and high efficiency of the two control system.The proposed control scheme can meet the requirements of the compressor,pumps,fan and other applications,and it has promising practicality and reference value.