| The Doubly Salient Electro-Magnet Motor (DSEM) widely applies to the aerospace system,because of its large power density,simple structure, and starter-generator integrated superiority. Inorder to reduce the volume and expense of the starting system, improve reliability and broaden theapplications, research on sensorless control of DSEM is researched in this project.The2D finite element analysis (FEA)model of DESM is firstly introduced in this thesis.Then themagnetic-field,flux linkage,and inductance in no-load and load are resolved by using FEA.Meanwhileboth the mathematical model and three-state electric-control strategy are studied which laid thetheoretical foundation for research on sensorless control of DSEM below.The initial position of the rotor sector is accurate identified by using the methods of injectinghigh-frequency low-voltage pulse vector and non-conducting phase terminal voltage.Both methodsare used to detect the bus current response and non-conducting phase terminal voltage response toidentify rotor sector.While the advantages in the hardware circuit, anti-interference and theimplementation of the method of non-conducting phase terminal voltage are highlighted. As themutation and transient of the starting process making the research of starting at low speed intodifficulty.So the current slope difference method for chopper control mode to identify full-cycleinductance and the commutation point current detection method for injection pulse vectors areproposed in the thesis to close-looped accelerate the motor steadily.Meanwhile the thesis describesthat the second method is more simple and reliable by comparative analysis.In addition, a kind of new high-speed unified sensorless control technology for DSEM is studiedwhich is applied to different chopper control modes.The characteristic of the terminal voltage underON-ONã€PWM-ONã€ON-PWM control strategies is analyzed and reconstructed by the coordinatetransformation based on different angles, then the commutation logic is discerned by capturing thezero crossings of reconstructed voltage. The method can not only identify the rotor commutationpoint, but slao can eliminate the effects of DC bias component under different control strategies.Finally, platform of hardwareand software of the control system is detailed descriped. |
