Abstract: An analysis of a surface mounted permanent magnet (SPM) machine by a 2D meshless method is provided. The 2D meshless method includes steps: discrete nodes are arranged in the region to be solved; based on Taylor expansion and weighted least squares principle, the derivative value of vector potential can be approximated as a linear combination of vector potential values of each node in the support region; partial differential equations are converted into algebraic equations; by solving the algebraic equations, the vector potential of each node can be calculated, and then the distribution of the flux line and the flux density can be obtained. According to the electromagnetic calculation constraints of the machine, parameters such as the back electromotive force and electromagnetic torque of the machine can be obtained.

Abstract: The present disclosure provides a method for reducing the electromagnetic vibration of a fractional slot concentrated winding (FSCW) permanent magnet (PM) motor, which provides a guidance for the low vibration design of FSCW PM motor. The implementation of the method includes: Based on Nyquist Shannon sampling theorem, the modulation effect of electromagnetic force in the air gap is obtained, and the electromagnetic force component that contributes the most to the electromagnetic vibration of the FSCW PM motor is determined. The equivalent analytical model of PM flux density is established to obtain the phase relationship between different flux density harmonics. According to Maxwell stress equation, the internal relationship between each order of flux density harmonics and electromagnetic force harmonics is obtained. A new magnet structure of the PM motor is designed, and specific flux density harmonics are injected to reduce the electromagnetic force and electromagnetic vibration of the FSCW PM motor.

Abstract: The present invention relates to a fault-tolerant modular permanent magnet assisted synchronous reluctance motor (PMaSynRM) and provides a modular winding connection method. The modular winding connection is to change the positions of inlet and outlet coils based on the slot electrical potential star vectogram. Then, each module has a separate set of winding and the left and right relative distribution will be adopted on the winding connection. The invention has the advantages of modularization in structure, high independence between the modules, effectively avoiding overlapping of magnetic lines between the modules, and improving fault tolerance and reliability of the motor. The invention has the advantages of modularization in structure, high independence between the modules, magnetic decoupling between the modules, and improvement of fault tolerance and reliability of the motor.

Abstract: A field modulated doubly salient motor and a design method for a distribution of salient pole teeth thereof are provided. The motor includes a stator and a mover, wherein the stator includes a stator core, two sets of windings, and two sets of permanent magnets. Each of the stator teeth is split into two field winding teeth, and each of the field winding teeth is split into two salient pole teeth. The two sets of windings are respectively armature windings and field windings, wherein the armature windings are wound around stator teeth, and the field windings are wound around adjacent field winding teeth that are split from different stator teeth. The two sets of tangentially magnetized permanent magnets are respectively placed on openings and bottoms of field winding slots, and permanent magnets placed in the same slot or at the same positions of adjacent slots have opposite polarities.

Abstract: A field modulated doubly salient motor and a design method for a distribution of salient pole teeth thereof are provided. The motor includes a stator and a mover, wherein the stator includes a stator core, two sets of windings, and two sets of permanent magnets. Each of the stator teeth is split into two field winding teeth, and each of the field winding teeth is split into two salient pole teeth. The two sets of windings are respectively armature windings and field windings, wherein the armature windings are wound around. stator teeth, and the field windings are wound around adjacent field winding teeth that are split from different stator teeth. The two sets of tangentially magnetized permanent magnets are respectively placed on openings and bottoms of field winding slots, and permanent magnets placed in the same slot or at the same positions of adjacent slots have opposite polarities.

Abstract: A parametric equivalent magnetic network modeling method for multi-objective optimization of permanent magnet motor is provided. Firstly, the disordered region and the regular region of the magnetic flux lines in the motor are divided, and the dynamic mesh model of the disordered region and the magnetic circuit model of the ordered region is constructed. Then, the dynamic mesh model and the magnetic circuit model are connected, and the parametric equivalent magnetic network model of the motor is established. The nonlinear matrix is used to solve the equations, and the magnetic potential of each node is solved to obtain the torque characteristics of the motor. Then, the variable sensitivity analyses of the average torque and torque ripple are carried out by using the parametric equivalent magnetic network model, and the response surface models of the average torque and torque ripple are established by selecting the high sensitivity variables.

Abstract: A parametric equivalent magnetic network modeling method for multi-objective optimization of permanent magnet motor is provided. Firstly, the disordered region and the regular region of the magnetic flux lines in the motor are divided, and the dynamic mesh model of the disordered region and the magnetic circuit model of the ordered region is constructed. Then, the dynamic mesh model and the magnetic circuit model are connected, and the parametric equivalent magnetic network model of the motor is established. The nonlinear matrix is used to solve the equations, and the magnetic potential of each node is solved to obtain the torque characteristics of the motor. Then, the variable sensitivity analyses of the average torque and torque ripple are carried out by using the parametric equivalent magnetic network model, and the response surface models of the average torque and torque ripple are established by selecting the high sensitivity variables.

Abstract: The present invention relates to a fault-tolerant modular permanent magnet assisted synchronous reluctance motor (PMaSynRM) and provides a modular winding connection method. The modular winding connection is to change the positions of inlet and outlet coils based on the slot electrical potential star vectogram. Then, each module has a separate set of winding and the left and right relative distribution will be adopted on the winding connection. The invention has the advantages of modularization in structure, high independence between the modules, effectively avoiding overlapping of magnetic lines between the modules, and improving fault tolerance and reliability of the motor. The invention has the advantages of modularization in structure, high independence between the modules, magnetic decoupling between the modules, and improvement of fault tolerance and reliability of the motor.

Abstract: This invention proposes a method to regulate high efficiency region of permanent magnet motor. The internal relationship between the point with maximum efficiency and the points around it is firstly revealed. Then, the optimal combination of copper loss, iron loss and permanent magnet eddy-current loss is presented when maximum efficiency point moves toward different directions. Hence, the method for regulating high efficiency region can be obtained. This method can be suitable for any type of permanent magnet motors, which can adjust high efficiency region to the dense working point area of the motor under different operating conditions according to design requirements. If this method is used into electric vehicle, it can combine the high efficiency region with the electric vehicle driving cycle to reduce energy consumption and enhance the life mileage of electric vehicle effectively.

Abstract: A permanent magnet brushless motor has a stator, an armature winding, a rotor, and a permanent magnet. The stator is provided with an armature groove. The armature winding is placed in the armature groove. The stator and the rotor are spaced apart by an air gap; the permanent magnet is attached to the surface of the rotor, and is magnetized by a Halbach array structure. The motor is an eight-phase motor, and phases are evenly distributed at a phase belt angle of 45°. The motor and the proposed control algorithm have good fault-tolerant effects, and the average torque after fault tolerance is basically consistent with that in normal operation.

Abstract: An electric motor includes 3 stators and 1 rotor which employs distributed winding. The axial magnetic circuit generates permanent magnet torque, while the radial magnetic circuit generates reluctance torque. By decoupling the axial and radial magnetic circuits, the separation and the independent control of the permanent magnet torque and the reluctance torque are realized. Each stator and rotor can be processed independently, and modular installation can be processed, thereby reducing the difficulty of motor processing.

Abstract: The invention proposes a fault-tolerant field-oriented control method of five-phase interior permanent-magnet fault-tolerant linear motor (IPM-FTLM) with two nonadjacent short-circuit phase faults. Firstly, the extended Clark transformation matrix can be obtained according to the principle that magnetic motive force (MMF) keeps constant before and after the two-phase open-circuit faults, the constraint that the sum of healthy phase currents is zero and the adjacent two-phase current amplitude is equal. The back electric motive force (EMF) can be estimated by the transposed matrix. The nonlinear strong coupling system becomes the first-order inertia system when using the internal mode controller, the first-order inertia feed-forward voltage compensator and back-EMF observer, as the motor is with fault.

Abstract: Disclosed is a double-stator linear vernier permanent magnet (DS-LVPM) motor and method to increase the magnetic field modulation effect. The motor contains a primary, and first and second secondaries on both sides of the primary, spaced by an air gap. The motor secondary includes modulation teeth. The primary is bilaterally symmetrical, and permanent magnets (PM) are embedded in the yoke of the primary core elements. The design solves the inherent problem of flux leakage at the end of PMs for conventional VPM motors, so as to improve utilization of PMs, thereby increasing thrust density of the motors. Additionally, the motor secondaries are laminated by silicon steel sheet, which saves PM material and significantly reduces cost for linear long stroke applications. By adjusting PM structure parameters, the design can use finite element method (FEM) to calculate repeatedly to get PM structure parameters corresponding to maximum electromotive force (EMF).

Abstract: Disclosed are fault-tolerant permanent-magnet vernier cylindrical electric motors with an electromagnetic suspension and a fault-tolerant vector control method for a short circuit of two adjacent phases. The fault-tolerant permanent-magnet vernier cylindrical electric motor with an electromagnetic suspension and the fault-tolerant vector control method for a short circuit of two adjacent phases suppress motor thrust ripples caused by a fault of two adjacent phases of an electric motor. The dynamic performance and the steady-state performance thereof are consistent with those under a normal state, and the switching frequency of a voltage source inverter is constant.

Abstract: Disclosed are fault-tolerant permanent-magnet vernier cylindrical electric motors with an electromagnetic suspension and a fault-tolerant vector control method for a short circuit of two adjacent phases. The fault-tolerant permanent-magnet vernier cylindrical electric motor with an electromagnetic suspension and the fault-tolerant vector control method for a short circuit of two adjacent phases suppress motor thrust ripples caused by a fault of two adjacent phases of an electric motor. The dynamic performance and the steady-state performance thereof are consistent with those under a normal state, and the switching frequency of a voltage source inverter is constant.

Abstract: A permanent magnet brushless motor has a stator, an armature winding, a rotor, and a permanent magnet. The stator is provided with an armature groove. The armature winding is placed in the armature groove. The stator and the rotor are spaced apart by an air gap; the permanent magnet is attached to the surface of the rotor, and is magnetized by a Halbach array structure. The motor is an eight-phase motor, and phases are evenly distributed at a phase belt angle of 45°. The motor and the proposed control algorithm have good fault-tolerant effects, and the average torque after fault tolerance is basically consistent with that in normal operation.

Abstract: The invention proposes a fault-tolerant field-oriented control method of five-phase interior permanent-magnet fault-tolerant linear motor (IPM-FTLM) with two nonadjacent short-circuit phase faults. Firstly, the extended Clark transformation matrix can be obtained according to the principle that magnetic motive force (MMF) keeps constant before and after the two-phase open-circuit faults, the constraint that the sum of healthy phase currents is zero and the adjacent two-phase current amplitude is equal. The back electric motive force (EMF) can be estimated by the transposed matrix. The nonlinear strong coupling system becomes the first-order inertia system when using the internal mode controller, the first-order inertia feed-forward voltage compensator and back-EMF observer, as the motor is with fault.

Abstract: The invention proposes a new motor with separated permanent magnet torque and reluctance torque. Meanwhile, the optimal efficiency control method for this motor is proposed. This invention belongs to the field of motor and its drive system. The proposed motor includes 3 stators and 1 rotor (composed of 2 axial rotors and 1 radial rotor), the radial stator employs distributed winding, the axial stator adopts concentrated winding. The distributed winding and the radial reluctance rotor structure contribute to higher reluctance torque, while the concentrated winding and the surface mount permanent magnet structure offer higher permanent magnet torque. In the view of the magnetic circuit, the axial magnetic circuit generates the permanent magnet torque, and the radial magnetic circuit generates the reluctance torque. By using the decoupling of axial and radial magnetic circuits, the separation and the independent control of the permanent magnet torque and the reluctance torque are realized.

Abstract: Disclosed is a double-stator linear vernier permanent magnet (DS-LVPM) motor and method to increase the magnetic field modulation effect. The motor contains a primary, and first and second secondaries on both sides of the primary, spaced by an air gap. The motor secondary includes modulation teeth. The primary is bilaterally symmetrical, and permanent magnets (PM) are embedded in the yoke of the primary core elements. The design solves the inherent problem of flux leakage at the end of PMs for conventional VPM motors, so as to improve utilization of PMs, thereby increasing thrust density of the motors. Additionally, the motor secondaries are laminated by silicon steel sheet, which saves PM material and significantly reduces cost for linear long stroke applications. By adjusting PM structure parameters, the design can use finite element method (FFM) to calculate repeatedly to get PM structure parameters corresponding to maximum electromotive force (EMF).

Abstract: Disclosed are a ferrite catalyst and preparation methods thereof. The catalyst is provided with a formula below, wherein A is Mg atom, Zn atom or a mixture of both atoms at any ratio; D is one or more atoms selected from the group consisting of Ni, Co, W, Mn, Ca, Mo or V atom; Z is a catalyst carrier, which is one or more selected from the group consisting of calcium phosphate, calcium dihydrogen phosphate, aluminum phosphate, aluminum dihydrogen phosphate, ferric phosphate, magnesium phosphate, zinc phosphate, Mg—Al hydrotalcite, calcium carbonate, magnesium carbonate; a=0.01-0.6; b=0-0.30; c is a number balancing each valence; x, y represent the amounts of principal catalyst and carrier Z respectively, wherein the weight ratio y/x=0.5:1-7:1.