Sensorless Vector Control Of AC Motors Based On DSPACE

Sencerless vector control (SVC), as one of the AC motor control technologies, combines vector control and general inverters. With the advantages of wide control range, high accuracy, fast response, controllable torque, low cost, high reliability and unrestricted of environment, the reaserch of sencerless vector control (SVC) methods have presently became the hotspot of the drive control aerea. While the control perfomence is required to be higher, the control algorithm becomes more complicated, which make the traditional developing methods, like DSP control methods, need a long developing cycle. The dSPACE is a software and hardware platform for the real-time control system based on the MATLAB/SIMULINK. It has the excellent real-time, extensible performance and the high reliability. So, as a control platform, dSPACE can completely satisfy the requirements of real-time system and generate algorithm codes automatically at the same time.Firstly in this paper, the motor control real-time model was established in MATLAB/SIMULINK using the rapid control prototype (RCP) method based on the dSPACE. Then the realtime experiments were carried on the motors, according to the experiments results, the limitation of the speed controller was analyzed and an improved one was designed. The improved speed controller can effectively improve the performance of the vector control system.Afterwards, two categories of SVC methods which are PI controller algorithm and MRAS algorithm were studied and improved. Both of the methods are based on fundamental excitation. For PI controller method, an PI controller with variable arguments was introduced to substitute the original liner PI controller in order to enhance the estimate performance. And for MRAS model, an improved voltage model was applied, which can avoid the disadvantages that pure integrator has caused, and then an estimate method which can simultaneously estimate the speed and the motor parameters was studied to solve the motor parameter changing problems in the actural operation. All the methods studied above were proved to be viable.Additionally, this paper studies an effective method to estimates speed and position to satisfy the needs of full-speed implement for surface mounted permanent magnet synchronous motors (SPMSM). This method is based on a speed-adaptive observer that is enhanced with a high frequency signal injection technique which is fit for SMPSM drive to operate at low speeds and standstill. This enhanced speed-adaptive observer combined the fast dynamic response of adaptive model with steady-state accuracy of HF (High Frequency) signal injection method can start up under close loop condition. When it works at full speeds it obtains a smooth transition between the two regions.In the last part of this paper, the software and hardware configuration of dSPACE platform were introduced in details. By application examples, the use methods of RTI and ControlDesk are enumerated as well.