| With in-depth study and wide application of distributed generation, the micro-turbine power generation system based on high-speed permanent magnet synchronous motor has received widespread concern. The performance of micro-turbine power generation system depends on the control performance of high-speed PMSM. The high performance control system of high-speed PMSM needs reliable and accurate detection sensor. However, mechanical sensors may not only increase the cost of the system but also decrease the system's reliability. Sensor-less control is popular in the field of AC motor control. Sliding model observer is favored by scholars as a result of the advantages of robust performance, simple algorithm and easy implementation. However, it also brings the problem of chattering. Thus the paper mainly studies on PMSM sensor-less control system based on sliding mode observer (SMO) and research on the methods of inhibiting the problem of buffeting and improve performance of whole system.Firstly, the vector control system of PMSM is described in brief including SVPWM modulation and the mathematical model and vector control principle of PMSM. And then SMO is illustrated in detail, especially causes and suppression of buffeting. And PMSM sensor-less control system based on SMO is established.Secondly, in order to restrict chattering effectively, a new SMO based on Quasi-sliding mode is proposed, which substitutes a sigmoid function for the sign function with a variable boundary layer. In order to eliminate the amplitude and phase effect of low pass filter on EMF and suppress buffeting, an extended SMO which contains the structure of EKF is designed.Thirdly, In view of perturbations of resistance parameter, SMO with parameter identification online is devised to improve the steady state performance. And the effect of perturbations of resistance parameter is studied. And two ways of estimate rotor information is also evaluated there.Finally, the model of PMSM sensor-less control system based on SMO is build to verify the theoretical analysis. Simulation results show that the design of SMO and extended SMO can restrain the chattering validly and that SMO with parameter identification online can improve the steady state performance. Further, the experimental platform of PMSM vector control system is established. The experimental results verify that S-shaped functions of SMO can track rotor position accurately and restrain buffeting better and that the dynamic and static performance of speed is good. |
