92 results about "Air gap flux" patented technology

In a rotary electric motor, a stator contains a plurality of separate electromagnet core segments disposed coaxially about an axis of rotation. The core segments are affixed, without ferromagnetic contact with each other, to a non-ferromagnetic support structure. The rotor is configured in a U-shaped annular ring that at least partially surrounds the annular stator to define two parallel axial air gaps between the rotor and stator respectively on opposite axial sides of the stator and at least one radial air gap. Permanent magnets are distributed on each inner surface of the U-shaped rotor annular ring that faces an air gap. A winding is formed on a core portion that links axially aligned stator poles to produce, when energized, magnetic poles of opposite polarity at the pole faces.

Embodiments of the invention can include methods and systems for detecting rotor field ground faults in rotating machinery. In one embodiment, a system can include a rotor of the rotating machine comprising a plurality of field windings substantially disposed therein and a stator of the rotating machine comprising a plurality of stator windings substantially disposed therein, with an air gap existing between the rotor and the stator. The system can include a high-impedance grounding circuit at least temporarily connected between the rotor and a ground. Additionally, the system can include an air gap flux probe positioned at least temporarily between the rotor and the stator for measuring a magnetic flux density generated in the air gap during operation of the rotating machine. Finally, the system can further include an analyzer in electrical communication with the air gap flux probe for receiving an output of the air gap flux probe.

A starter-generator system may be used to supply sufficient starting torque to start an aircraft main engine. The main starter-generator stator winding may be connected to a constant frequency (CF) power source to create a rotating field in the main starter-generator air gap. This rotating field, in turn, may induce current on the main rotor winding, which may be a closed circuit formed by main rotor field winding and exciter armature winding. The interaction between the main rotor current and the air gap flux may give rise to the starting torque to start the main engine. Adjusting the voltage supplied to the exciter stator field winding can modify the induced voltage and current on the rotor circuit to control the rotor current and starting torque. The starter-generator system may also be used to start an aircraft main engine by directly connecting the main stator winding to a power source without powering the exciter stator.

A high temperature superconducting synchronous motor having an inductor topology that increases the air gap flux density in direct relation to motor power density by trapping flux and concentrating it in the air gap to obtain more power in the same volume or smaller volume for the same power, and whose geometry enables the induction motor to be lighter than superconducting motors without the inductor topology, the motor being positioned in a housing, and the motor comprising: a) stator means having an armature winding to provide a stator field; b) rotor means positioned within the stator field and on which is disposed at least two polygon shaped ring or coil means along the same axis to provide separated and spaced apart relationship field solenoids; c) at least three high temperature superconducting plate means disposed in alternating relationship between the ring or coil means to hold the ring or coil means together to trap magnetic field and shape flux lines; and d) cooling means to cool the superconducting in the rotor to a temperature below the critical temperature of the superconducting plate means.

The invention relates to a BSRM modeling method considering the edge diffusion effect. The method includes the following steps that: Maxwell stress method integral paths considering the edge diffusion effect are selected respectively according to a stator movement region and a rotor movement region of a BSRM air gap when an angle theta by which rotor tooth poles deviate from stator tooth poles is equal to 0 degree and when the theta is not equal to 0 degree; based on the Maxwell stress method integral paths, air gap flux densities when theta is equal to 0 degree and when the theta is not equal to 0 degree are calculated; alpha-direction levitation forces and beta-direction levitation forces which are borne by the rotor tooth poles, and electromagnetic torques can be obtained through calculation according to the air gap flux densities; and an alpha-direction and beta-direction levitation force and electromagnetic torque analytical model of a BSRM is established. With the BSRM modeling method adopted, BSRM analytical modeling is realized, and the edge diffusion effect is considered, and therefore, modeling accuracy is high.

The invention discloses a bearing-free magnetic flux switching permanent magnet motor rotor eccentric displacement compensation controller. A real-time rotating speed is input into an adaptive LMS filter, and the output of the adaptive LMS filter is a displacement compensation value; a rotor radial eccentric displacement and a rotor displacement command value and a displacement compensation valueare subjected to error comparison, and an error value is input into a corresponding PID controller; the PID controller converts the error value into two control components of the suspension force andinputs the suspension force into a suspension force winding current calculation module; a three-phase torque winding control current and a three-phase torque winding phase voltage are input into a torque winding air gap magnetic field estimation module, and the torque winding air gap magnetic field estimation module obtains rotor winding air gap flux linkage amplitude and phase and inputs the rotor winding air gap flux linkage amplitude and phase into the suspension force winding current calculation module; the suspension force winding current calculation module obtains a suspension force winding control current command value, and an inverter performs compensation control on the eccentric displacement of the suspension force rotor; the actual eccentric position center of the rotor does notneed to be detected, and the detection precision is improved.

The invention discloses a linear Halbach permanent magnet-arranged superconductive eddy-current brake device with a superconductive switch, which is used for the non-contact electromagnetic braking of levitated bodies and comprises linear Halbach combination magnets and a superconductive eddy-current brake, and the superconductive eddy-current brake is arranged on a levitated body for braking. The two linear Halbach combination magnets adopted as the sidewalls of a linear Halbach combination magnet track are vertically mounted over the sides of permanent magnet guide rails for levitation along the longitudinal extension direction of a line; and eddy-current coils of the superconductive eddy-current brake adopt superconductive material to form superconductive coils. The linear Halbach permanent magnet-arranged superconductive eddy-current brake device can obtain higher air gap flux than the conventional arrangement method within an available space, and meanwhile, a good magnetic shielding effect can effectively reduce the affection of a magnetic field on a magnetic levitation system. Moreover, the linear Halbach permanent magnet-arranged superconductive eddy-current brake device has the advantages of high eddy-current braking electromagnetic force and controllability.

The invention relates to an electromagnetic property testing simulator for a hydro-generator, wherein a stator winding is embedded in a stator core slot, the end of the stator winding is provided with a plurality of taps, a rotor winding is sheathed on a rotor pole and provided with a plurality of taps which are led out by multipath slip rings; a damper winding is embedded in a damping slot of the pole; the end and body of the damping winding are provided with a high-precision Hall current sensor and a temperature measuring element of a current measuring element series; a testing signal is emitted by a multichannel wireless digital telemetering device and enters a peripheral monitoring device; the rotor shaft extension end is provided with a torque and an online rotate speed telemetering device; and a stator core inner circle is provided with a magnetism-measuring element air-gap flux detector. The testing simulator can measure the rotate speed and torque of the generator under operating conditions; and simultaneously, the testing simulator can conduct false synchronization experiments of various short circuits and small angles, which are difficult to be conducted on true hydro-generator.

A 2-pole machine arrangement (10) has a stator (100) with windings (101) in conventional form, wound either in a single phase or three phase configuration. The rotor is formed of stacked laminations. The laminations include rotor pole pieces (107) located between the two magnetic poles. Each pole is formed by a pair of (embedded) permanent magnets (103), angularly spaced-apart by inter-magnet segments (106). The rotor pole pieces (107) include a series of evenly-spaced slots (109) and a central void (108). The slots (109) are of various lengths to direct the flux from the magnets (103) into the air gap (121) at a desired angle normal to the rotor surface. The slots 109 may be varied in width and angle to achieve the desired lowest waveform distortion under load and the highest air gap flux. The slots (109) also contribute to changing the saliency of the rotor.

The invention discloses a direct suspension force control method for a permanent-magnet-type bearing-free motor, and the method belongs to a bearing-free motor control method. The method controls the crest value and the direction of the space vector of a suspension winding stator flux through properly selecting the switch state of an inverter while maintaining the invariableness of an air-gap-flux composed by motor winding, and the suspension is controlled by adopting a closed loop, thereby further decoupling the torque control winding and the suspension winding. The invention is a control method with high suspension control precision, fast dynamic response and small motor parameter influence.

The invention discloses an air-gap field oriented control method and a system of an electrically excited synchronous motor, comprising the following steps: obtaining t-axis component of a given statorcurrent and a given air-gap flux linkage of the electrically excited synchronous motor, and obtaining m-axis component of the given stator current according to a unit power factor control relation; The phase angle and amplitude of the air-gap flux linkage are obtained by observing the flux linkage of the motor with the full-order flux linkage observation model. According to the phase angle of theair-gap flux linkage and the t-axis and m-axis components of the stator current, the pulse vector corresponding to the three-phase inverter connected with the motor is obtained by the vector controlalgorithm, so as to control the on-state of the switch in the three-phase inverter according to the pulse vector. The excitation voltage of the motor is controlled according to the magnitude of the air-gap flux linkage so that the magnitude of the air-gap flux linkage tracks a given air-gap flux linkage value. The present application can realize unity power factor control, and based on a full-order flux linkage observation model, the air gap magnetic field is accurately oriented, is less affected by parameters, can realize complete decoupling control, and has better performance.

An initiative risk protection system for a variable flow type vector control device of a high-capacity thyristor comprises a chip-level encryption and decryption control unit, a multisource/heterogeneous type industrial control network gateway, a compact type embedding type processing unit, an embedding type analyzing system, a risk evaluation and typical operation state analyzing unit and the like. The chip-level encryption and decryption control unit is used for supplying high-capacity synchronous motor rotor mechanical positions and rotating speed data information. The compact type embedding type processing unit is used for performing flow control and filtering on dynamic data of alternating current. The embedding type analyzing system is used for analyzing a current regulating type expert type rule base within half cycle of natural commutation. The risk evaluation and typical operation state analyzing unit is used for obtaining real-time information of voltage feedforward compensation and air gap flux linkage tracks. The initiative risk protection system aims at solving the problem of security holes, attack and virus invasion of industrial control networks of main mills and the like in the steel and iron industry, can perform initiative protection and remote real-time monitoring, and is safe, reliable, autonomous and controllable. An industrial equipment level information security control technique of the initiative risk protection system is further provided.

The invention discloses a direct controller of a radial displacement of a bearing-less asynchronous motor rotor. The direct controller is composed of a rotary speed controller, a radial displacement closed-loop controller and a torque winding air gap flux linkage estimation module; the rotary speed controller outputs a three-phase current to an electric motor torque winding; the radial displacement closed-loop controller is composed of a rotor eccentric displacement and eccentric angle computing module, a neuron PID controller, a levitation force winding current computing module, a three-phase power pulse-width modulation (PWM) inverter, a radial displacement sensor and a photoelectric encoder; according to the levitation force winding current computing module, five variables such as the radial levitation force amplitude, the rotor eccentric angle, the torque winding air gap flux linkage amplitude, the phase and the rotor position angle serve as inputs, three-phase levitation force winding current command values i'<2A>, i'<2B> and i'<2C> serve as outputs, and three-phase levitation force winding currents i<2A>, i<2B> and i<2C> required for stable rotor levitation are obtained through the three-phase power PWM inverter; the direct controller is simple and practical in structure, and independent control of the electromagnetic torque and the radial levitation force of a bearing-less asynchronous motor is achieved.

The invention discloses a bearingless asynchronous motor direct suspension force control method based on model prediction. The method comprises the following steps: obtaining radial suspension force amplitude and phase xi after PID adjustment and polar coordinate conversion of difference values of displacement signals x and y and given displacement signals x* and y* through suspension control; calculating synthesis air gap flux linkage psi 1m and phase eta through torque winding flux observer and vectorial resultant of three-phase current; inputting radical suspension force amplitude and phase xi, air gap flux linkage psi and phase eta into a suspension force calculating module, carrying out rectangular coordinate conversion treatment to obtain a suspension winding flux linkage reference value, screening a difference value with a suspension winding flux linkage reference value at the next moment through a target function to obtain a flux linkage in an optimal switch state, obtaining the voltage signal of a drive inverter after SVPWM modulation of the flux linkage, and finally obtaining three-phase voltage required for a control motor so as to realize bearingless asynchronous motor direct suspension force control. The method can solve the problem that precision is insufficient and is greatly influenced by motor parameters caused by traditional suspension force indirect control.

The present invention relates to a Halbach permanent magnet linear oscillation motor, which comprises a housing, a stator main iron core, a rotor iron core and a linear axis. The stator main iron core is fixedly held in the housing and a winding is wound onto the stator main iron core. The rotor iron core is accommodated in the housing and is arranged opposite to the stator main iron core. A Halbach permanent magnet array is arranged outside the rotor iron core. The linear axis runs through the housing and is pivotably connected with the housing through a pair of linear bearings. The rotor iron core is fixedly arranged onto the linear axis and is in linkage with the linear axis. The Halbach permanent magnet array is adopted by the Halbach permanent magnet linear oscillation motor, so that an air gap flux larger than that of a conventional magnet can be obtained. Meanwhile, the Halbach permanent magnet linear oscillation motor is good in magnetic shielding effect and can reduce the thickness of a rotor magnetic-conductive yoke.

The invention discloses a current harmonic injection type vernier reluctance motor and system. The vernier reluctance motor body comprises a stator, a rotor and a winding. The stator and the rotor arein salient pole structures. The winding is a single-layer concentrated winding. Two sinusoidal alternating currents with different frequencies are injected into each phase of the winding. On the basis that the current in the winding is three-phase symmetrical current, two sinusoidal alternating current components with different frequencies in the winding are used to produce armature magnetomotiveforces with the same number of pole-pairs but different rotation speed. One magnetomotive force produce a space magnetic field with the same number of pole-pairs and the same rotation speed with theother armature magnetomotive force through the modulation of an air-gap flux guide, and a certain angle is between the space magnetic field and the other armature magnetomotive force. The magnetic field interacts with the other armature magnetomotive force to generate torque and realize electromechanical energy conversion. Compared with the prior art, the motor has the advantage that the current utilization ratio is increased by 11% compared with a direct current injection type vernier reluctance motor. In addition, the complexity of the controller part of the motor system is significantly reduced, and the cost is greatly reduced.

The invention relates to a synchronous AC electric motor with concentrated windings (2), whereby one primary side pole is comprised of a series of toothed-modules (4) with each toothed-module (4) being connected in the correct electrical phase sequence to a corresponding phase (11) of the motor electrical supply (5). In order to provide a highly optimized concentrated winding motor design applicable equally to either linear or rotating machines, which retains the performance benefits of existing concentrated-winding motors it is proposed that neighboring modules (4) are wound so as to have alternating polarities, whereby the number of toothed-modules (4) comprising a primary side pole is exactly equal to twice the number of motor phases (5), and that the motor is designed to operate using an air-gap flux component which is harmonic of the fundamental phase current frequency.

The invention discloses an excitation synchronous motor rotor initial position estimation method. The method includes the following steps that: under a condition that alternating current is not introduced into stator windings, excitation step current signals are introduced into a rotor winding; after an excitation synchronous motor generates a magnetic field due to the excitation step current signals, the induced electromotive forces of the three-phase stator windings are detected through a voltage sensor, and the induced electromotive forces of the three-phase stator windings are transformed into stator back-electromotive force components in an alpha-beta coordinate system through 3/2 coordinate transformation, and the stator back-electromotive force components are inputted into a voltage model, the position angle of air gap flux is obtained, and the position angle of the air gap flux is a rotor position angle, and therefore, the initial position of a rotor can be estimated. According to the method of the invention, the initial position of the rotor can be realized without a position sensor required, and therefore, the method is simple and practical, can accurately estimate the initial position of the rotor and is suitable for various kinds of electric excitation synchronous motors.

The invention provides a method for calculating load electromagnetic excitation force waves of a built-in permanent magnet synchronous motor, and the method comprises the steps: carrying out the calculation of air gap flux density under a no-load condition through a finite element to obtain the relation between magnetomotive force and magnetic conductance under the no-load condition; simulating toobtain a d-axis magnetic conductance model of an armature magnetic field by utilizing a method of freezing magnetic conductivity, accurately calculating a magnetomotive force and magnetic conductancerelationship generated by independent action of a winding under a load condition according to the model, and solving an air gap flux density generated by the winding; superposing the air gap flux densities generated by the permanent magnet and the armature winding by using a superposition principle to obtain a built-in load air gap flux density expression; according to a Maxwell tensor method, putting magnetomotive force and air gap magnetic conductance component results into an electromagnetic force density expression to accurately obtain force wave amplitudes under different frequencies anddifferent orders.

The invention provides a permanent magnet synchronous machine (PMSM) possessing an assembled magnetic effect. The PMSM comprises a stator and a rotor. Air gaps exist between the stator and the rotor. The stator includes a stator core and a stator winding. The rotor includes a rotor core, a rotating shaft and permanent magnet steel. The stator winding is a centralized winding. The rotor is an eccentric rotor. Ends of the permanent magnet steel are directly connected with each other. The air gaps between the stator and the rotor are non-uniform air gaps. The invention has the following positive effects that: (1) distribution of air-gap flux density can be optimized through improving a rotor structure and the air gap flux can be very close to a sinusoidal waveform by using the non-uniform air gaps; (2) magnetic flux leakage on the ends can be effectively reduced because the ends of the permanent magnet steel are directly connected with each other, and simultaneously a magnetic isolation bushing is not needed to be installed on a rotating shaft side so that a requirement of a rotating shaft material can be reduced, wherein the rotating shaft can adopt a magnetic conductive material and/or a non magnetic conductive material.

The invention discloses a control method of a spherical electric vehicle use magnetic suspended flywheel battery. In the working processing of the spherical flywheel battery, a control mode that a magnetic field laminates differential is adopted, that is, a pair of upper stator poles and a pair of lower stator poles are provided with bias coils and control coils respectively, the bias coils of the two stator poles are in series connection, and through a constant current, a bias magnetic field for a magnetic spherical faced bearing to work is provided; the control coils on each pair of the stator poles are in series connection, magnetic fluxes generated by the control coil and the control current in the control coil are added up in the pair of stator poles, and the magnetic fluxes of the control coil and the control current generated in the control coil are subtracted in the other pair of stator poles, therefore an air gap flux between the pair of the stator poles and a spherical flywheel is increased, an air gap flux between the other pair of the stator poles and the spherical flywheel is reduced, according to a formula I, B is a magnetic induction intensity, S is a stator spherical face area of the spherical faced bearing, mu0 is an air permeability, electromagnetic force bore at one side is increased, and electromagnetic force bore at the other side is reduced, therefore the position of the spherical faced flywheel is adjusted to be always at a balanced position.