Study On A Double-Sided Linear Flux-Switching Permanent Magnet Machine For Direct Drives

The linear flux-switching permanent magnet motor (LFSPM machine) and the switched reluctance motor (SRM) have a same operation principle. Their doubly salient structure with permanent magnets on the primary allow them having low costs. The permanent magnet-type of excitation makes LFSPM machines have excellent features as all tranditional PM motors. Based on the requirements of precision direct drives, we design a double-sided linear flux switching permanent magnet motor (DLFSPM machine). The motor performance and design parameters are optimized. Firstly, the operating principle of DLFSPM machine is validated with finite element method, also the flux linkage, the back EMF, the thrust forces, the cogging force and other performences. The cogging force is calculated by the finite element method for the reduction of DLFSPM motors. The model of unbalanced magnetic pull force (UMF) of DLFSPM machine is derivated. The UMFs under various phase currents and air gap are analyzed by FEM. Then, we have sdudied on manufacture process of DLFSPM machine. At last experiment are carried out to verify the simulation results.Main achievements of this thesis are as follows:? For the requirements of direct drives, the primary permanent magnet DLFSPM machine is selected, also its main parameters, the teeth numbers. The fluxlinkage, back EMF, cogging force, and the thrust force are optimized under diffrent length of the magnetization direction of the permanent magnet, the gap length, by using the FEM, etc.? For the double sailent structure of DLFSPM machine we used the method of asymmetrical distribution (ADST) and stator teeth displasement (SSPT) for cogging force reduction. The method of finite element method to calculate the core loss of DLFSPM machine at low speeds. Thus, the cogging force calculation considering hysteresis effects is carried out. The performances are compared, and verified the feasibility of the cogging force reduction and the calculation of hysteresis force.? The model of unbalanced magnetic force for DLFSPM machine is established. The expressions of UMF are obtained, and this explains the principle of UMF during the operation of DLFSPM motor. The characters of UMF under different curents and PM excitation are simulated by FEM. At last, the performances of DLFSPM machine are analyzed.? The manufacture process of DLFSPM machine is studied. Tests were carried out to verify the effectiveness and feasibility of DLFSPM motor design by using the control systems of DLFSPM machine.