249results about How to "Increase sine" patented technology

A magnetized salient pole type mixed excitation synchronous motor mainly comprises a stator and a rotor, wherein the stator is of structure identical with that of a stator of a conventional permanent-magnet synchronous motor, the rotor is similar to a rotor of a salient pole type excitation synchronous rotor in shape and provided with an electromagnetic winding, and quadrature axis air gap is larger than direct axis air gap. Each magnet pole of the rotor is respectively provided with two 'V'-shaped magnetic steel grooves, steel magnets with same polarity are respectively disposed in the magnetic steel grooves, and finally, the double 'V'-shaped mixed excitation magnetic pole structure with quadrature axis magnetic resistance higher than direct axis magnetic resistance. By means of the excitation magnetic winding, induced potential can be directly adjusted, and irreversible demagnetization on the steel magnets can be avoided. Further, on the condition of applying quadrature axis current and magnetizing direct axis current at the same time, magnetized magnetic resistance torque component can be generated so as to increase torque density of the motor.

The invention discloses a high-adaptability three-dimensional measuring method based on color structured light in a three-dimensional scanning system. The method comprises the following steps of: coding according to the Gray coding principle by use of 6 pure colors; performing sinusoidal modulation of three components R, G and B at the same time to obtain a color grating for projection; designing an auxiliary grating according to the color grating; projecting the designed color grating and auxiliary grating to a measured object; performing superposition operation of the collected two grating deformation diagrams to obtain the reflectivity of each pixel; compensating the grating deformation diagrams according to the reflectivity of each pixel; performing color image division of the compensated grating deformation diagrams; decoding the divided image to obtain corresponding phase period information; graying the compensated grating deformation diagrams and obtaining the wrapped phase value of each pixel by Fourier transform; realizing phase unwrapping according to the decoded phase period information of each pixel; and finally, realizing three-dimensional reconstruction according to the corresponding relationship between the phase and the object height information.

The invention discloses a double-stator permanent-magnet vernier wind driven generator, and belongs to the field of motor manufacturing. The double-stator permanent-magnet vernier wind driven generator comprises an outer stator (4), an inner stator (8) and a rotor (6), wherein the outer stator is provided with a pear-shaped groove and first stator teeth; the inner stator (8) is provided with second stator teeth (9), and each second stator tooth (9) is provided with a flux modulation electrode (10) and a flux modulation electrode groove (11); the rotor (6) is of a cup-shaped structure, and a Halbach-structure permanent magnet (7) is arranged on the rotor; the tooth number of the first stator teeth of the outer stator (4) is equal to that of the teeth of the flux modulation electrode (10); moreover, the pear-shaped groove of the outer stator (4) and the flux modulation electrode (10) are oppositely distributed and arranged, and the first stator teeth of the outer stator (4) and the flux modulation electrode groove (11) are oppositely distributed and arranged. The double-stator permanent-magnet vernier wind driven generator disclosed by the invention is capable of generating a high-sine air-gap magnetic field, and has the characteristic of a high output torque.

The invention discloses a bearing-free asynchronous motor RBF neural network self-adaptive inverse decoupling control and parameter identification method. An SVPWM module, a voltage inverter, a bearing-free asynchronous motor and a load of the bearing-free asynchronous motor form a whole serving as a composite controlled object. Two radial basis function neural networks are adopted to achieve inverse control and parameter identification conducted on the composite controlled object. A self-adaptive inverse controller is formed by using an RBF neural network through learning, and is serially connected in front of the composite controlled object, errors of a feedback signal and a given signal are input into an inverse controller, and accordingly closed-loop control is formed, then a self-adaptive parameter identifier is formed by using one RBF neural network through learning and identifies output quantity speed and displacement of the composite controlled object, speed-less and displacement-free sensor control is achieved, online learning of an estimation signal is aided by means of a learning algorithm, and non-linear dynamic decoupling control of the bearing-free asynchronous motor is achieved. The bearing-free asynchronous motor RBF neural network self-adaptive inverse decoupling control and parameter identification method is high in control speed and higher in identification accuracy, and a control system is excellent.

The invention relates to power technique fields, especially direct current power device with power factor emendation function, method of increasing power factor of power device and adjusting the output voltage of the power device. The method of increasing power factor of power device uses reactor to short alternating current to improve current wave before commutating bridge, and uses reactor to short alternating current at later evening, so the input current wave sinus degree is more higher, power factor is higher, harmonization emission extent is smaller. The invention increases power factor, and also provides method of adjusting said direct current power device output voltage, so the output voltage can be adjusted real time.

The invention discloses a method for rejecting the central potential drift of a three-phase four-bridge arm three-level inverter. The SVPWM vector of the three-phase four-bridge arm three-level inverter is reduced from the traditional three-dimension to a plane, the switch statuses of the first three bridge arm and the fourth bridge arm are separately selected, the vector table of the first three bridge arm three-level space is made full use of to select a zero vector and a length vector, small vectors are used in pairs while mid-sized vectors can not be used directly, neighboring vectors are combined into mid-sized vectors, and the switch status of the fourth bridge arm is selected according to the principle of the offset between the charge effect and the discharge effect of a capacitor. The algorithm is simple and easy to be realized, and can not only contain asymmetric load but also realize that the average value of the current which passes through the neutral point of a DC (direct current) side capacitor is strictly being zero under any load power factors and modulation ratio, thus effectively rejecting the drift of neutral point potential. No sample current is required in the algorithm, thus reducing the requirement of the system to the neutral point of the DC side capacitor. An open-loop control and a closed-loop control are respectively available.

The invention discloses a one-phase open-circuit fault-tolerant direct thrust control method for a five-phase permanent magnet linear motor. Firstly, a Clark transform matrix and an inverse matrix thereof are derived based on fault-tolerant phase current. On the above basis, a stator flux linkage on alpha-beta is derived, a stator virtual flux linkage is defined according to the requirements of acircular stator flux linkage trajectory, and thus the voltage compensation on alpha-beta is derived. The stator actual voltage on the alpha-beta is derived by a modulation function of a voltage sourceinverter, and voltage is combined with voltage compensation and stator current, and a stator virtual flux linkage and thrust are observed by a stator flux observer and a thrust observer. Then statorvirtual target votlage is calculated according to given thrust, a given stator flux linkage amplitude and the observed stator virtual flux linkage and thrust. Finally, the stator actual voltage is calculated by the voltage and the voltage compensation, and the motor is controlled by the voltage by the voltage source inverter. According to the method, a thrust fluctuation caused by a motor failureis suppressed, and more importantly, the dynamic performance and steady state performance are consistent with that in a normal condition.

The invention discloses a method for controlling the harmonic current of a full-power converter for suppressing wind power grid integration and a controller. The method comprises the following steps of: acquiring three-phase current and three-phase voltage of a grid-integrated converter, performing constant power conversion on an acquired network side three-phase current signal from a static three-phase coordinate system to synchronous, five-time, seven-time, eleven-time and thirteen-time rotary coordinate systems, and performing low pass filtering to obtain a dq axis component; and obtaining a dq axis control voltage by adopting a network voltage directional vector control way, performing constant power conversion on the control voltage from synchronous, five-time, seven-time, eleven-time and thirteen-time rotary coordinate systems to the static three-phase coordinate system to obtain a fundamental wave control voltage and five-time, seven-time, eleven-time and thirteen-time harmonic wave three-phase control voltages, adding the fundamental wave control voltage and the five-time, seven-time, eleven-time and thirteen-time harmonic wave three-phase control voltages to obtain a final control voltage, and modulating the final control voltage to obtain a control switch signal, so that accurate control of five-time, seven-time, eleven-time and thirteen-time harmonic current is realized.

The invention discloses a voltage-sharing and power-sharing control method of a single-phase multi-module cascading solid-state transformer. A power main circuit part of the single-phase solid-state transformer is composed of an AC / DC rectifying input stage, a DC / DC middle stage and a DC / AC output stage. The rectifying stage and the middle stage serve as a system for controlling and designing, a common duty ratio control strategy based on single-phase d-q vector control is adopted in the input stage, the output direct voltage of the middle stage serves as feedback quantity of an outer voltage loop, the stability of the output direct voltage of the middle stage is achieved, and a unity power factor of an input end of a power grid is achieved; a control strategy based on voltage feed-forward and voltage feed-backward is introduced into all modules in the middle stage at the same time, the voltage feed-forward serves the benchmark of the voltage feed-backward, and errors of the voltage feed-forward and voltage feed-backward serve as the benchmark of a module current inner loop after being output by a voltage PI regulator. The front stage control strategy is interacted with the middle stage control strategy, and therefore the purposes that voltage and the power of modules of an SST are balanced, the power grid side unity power factor is achieved, the power grid current sine degree is high, the voltage stress of a switch tube is low, and the ripple of the output direct voltage of the middle stage is low.

The invention discloses a thrust optimization design method for a tubular permanent magnet synchronous linear motor, which comprises: firstly, building a solid model of the motor and setting run option parameters including the length of the primary iron core of the primary iron core stator of the motor; secondly, resolving the run option parameters by using a finite element method and building a finite element geometrical model; thirdly, calculating the optimization phase difference between the end forces at the two ends of the primary iron core stator according to a formula, and regulating the length of the primary iron core to obtain the optimal length of the primary iron core, which corresponds to the optimization phase difference; and finally, obtaining the tubular permanent magnet synchronous linear motor with the smallest thrust fluctuation through magnetization by the optimal length of the primary iron core, the half-open, half-closed, round-bottom grooved tooth-groove structure and a Halbach structure. In the invention, the thrust fluctuation is minimized by relieving the influences of magnetic drag produced by an end effect and a tooth-groove effect on the thrust fluctuation; the method is simple and effective; and the calculation accuracy is high, and the motor can serve as both an electrical motor and a generator.

The invention discloses a gas-magnetic mixed suspension type of 6-DOF (degree of freedom) planar motor comprising a stator substrate placed on the horizontal XY plane and a mover substrate floating on the stator substrate and parallel to the stator substrate. The four angles on the upper surface of the stator substrate are respectively provided with a first permanent magnet array, a second permanent magnet array, a third permanent magnet array and a fourth permanent magnet array. The wavelength direction of the first permanent magnet array and the third permanent magnet array thereof is the same with X axis and the wavelength direction of the second permanent magnet array and the fourth permanent magnet array is the same with Y axis. The four angles of the lower surface of the mover substrate are respectively provided with a first thrust winding, a second thrust winding, a third thrust winding and a fourth thrust winding. The wavelength direction of the first thrust winding and the third thrust winding thereof is the same with X axis and the wavelength direction of the second thrust winding and the fourth thrust winding is the same with Y axis. The four angles of the lower surface of the moving substrate are respectively provided with a first aerostatic bearing air cushion, a second aerostatic bearing air cushion, a third aerostatic bearing air cushion and a fourth aerostatic bearing air cushion.

The invention discloses a rotor sectional type flux switching motor and a method for improving the sine degree of back electromotive force thereof, belonging to the field of stator permanent-magnetic motors. The motor of the invention comprises salient pole stators, an armature winding, salient pole rotors and an electro-magnetic winding, wherein a permanent magnet is embedded in a gap between every two salient pole stators; the armature winding is wound on two salient pole stator arms connected with the permanent magnets; the electro-magnetic winding is wound on the permanent magnets in a vertical direction of the armature winding, and the excitation directions of adjacent permanent magnets are opposite; and the salient pole rotors are sectioned according to a space mechanical angle alpha along the axial direction. In the method of the invention, the back electromotive force generated by the salient pole stator A and the salient pole rotor A in the armature winding and the back electromotive force generated by the salient pole stator B and the salient pole rotor B in the armature winding have a phase difference of 180 degree electric angle, and correspondingly, the excitation directions of the permanent magnets embedded in salient pole stator teeth are opposite, so the back electromotive force of a synthesized unicoil has high sine degree and high amplitude value with the synthesized coefficient of 1.

The invention relates to a gas-magnet mixing suspended planar motor with easily expanded horizontal stroke, comprising a stator basal body arranged along a horizontal XY plane and a mover basal body suspended on the stator basal body and is parallel with the stator basal body. Two degrees of freedom Halbach permanent magnet arrays with wavelengths along the axis X and the axis Y directions are embedded on the surface of the stator basal body; each pair of magnetic poles of the two degrees of freedom Halbach permanent magnet arrays are formed by arraying first magnet to sixth magnet according to a four* four matrix; four corners of the lower surface of the mover basal body are respectively provided with a first thrust winding, a second thrust winding, a third thrust winding and a fourth thrust winding, wherein the wavelength direction of the first thrust winding and the third thrust winding are in the axis X direction; the wavelength direction of the second thrust winding and the fourth thrust winding are in the axis Y direction; four sides of the lower surface of the mover basal body are respectively provided with a first aerostatic bearing air-cushion, a second aerostatic bearing air-cushion, a third aerostatic bearing air-cushion and a fourth aerostatic bearing air-cushion.

The invention discloses a motor with stronger torque output ability and higher power density, which consists of stator (1) and rotor (4), wherein the rotor (4) lies in the interior or exterior of the stator (1); the stator (1) and rotor (4) are double-salient pole structures with the gathered winding (3) and permanent magnet (2) on the stator (1); the radial of second and fourth winding coils are faced with each gathered winding coil in the U-shaped magnetic iron groove of two adjacent stators (1); four winding coils connect front head to end sequently; the permanent magnet (2) is set between two adjacent U-shaped magnetic iron core.

A purpose of the present invention is providing a permanent magnet synchronous motor rotor structure which has high air gap flux density and is easy to generate back electromotive force with a sine wave. In a permanent magnet synchronous motor, a circumferential surface of the rotor is uniformly provided with a plurality of magnetic steel grooves which are independently enclosed and do not contact mutually. Every two magnetic steel grooves are arranged to form a V shape, an opening of the V shape faces excircle of the rotor, and a tip of the V shape faces a rotor center. Each magnetic steel groove is provided with magnetic steel. In each group of V-shaped magnetic steel grooves, two magnetic steel facing the excircle of the rotor core have a same magnetic pole, and magnetic poles of magnetic steel facing the excircle of the rotor core in two adjacent groups of V-shaped magnetic steel grooves are opposite with the magnetic pole of the two magnetic steel. The excircle of the rotor goes down toward the center with depth delta and smooth transition at a crossing position of axes, which means that air gap width at the crossing position is less than air gap width at a straight axis position by delta. Through improving the rotor, the permanent magnet synchronous motor rotor has high mechanical strength and a large salient pole ratio, and weakened magnetism speed expansion is facilitated.

The invention relates to a Halbach array parallel rotor composite excitation brushless synchronous motor, which comprises a rotor and a stator for accommodating the rotor, wherein the stator comprises a magnetic groove sleeve, an annular exciting winding and the like; the magnetic groove sleeve is fixed on a motor end cover through bolts and is not contacted with the rotor; and the annular exciting winding is fixed at the groove of the magnetic groove sleeve. The rotor consists of a rotating shaft and a Halbach rotor and an electric excitation rotor which are arranged on the rotating shaft in parallel, and the Halbach rotor comprises a non-magnetic rotor supported by the rotating shaft and a Halbach array permanent magnet arranged on the surface of the non-magnetic rotor; the electric excitation rotor comprises a claw pole structure connected with the rotating shaft; and the Halbach rotor is separated from the electric excitation rotor by a separating magnetic ring formed by air gaps. The brushless synchronous motor can reduce the eddy current loss of the rotor, enlarge the adjustable range of a magnetic field and improve the power density of the motor, and has the advantages of high reliability and good energy-saving effect.

A defocusing projection grating measurement method based on a Sierra Lite dithering algorithm mainly aims to generate a two-value dithering grating through the Sierra Lite dithering algorithm, improve the sine performance of the grating after defocusing and then improve the quality of a phase position. The defocusing projection grating measurement method includes the implement steps of generating a sine grating by a computer, calculating dithering output starting from the pixel at the top left corner of an image of the grating, calculating a quantization error of the pixel according to a gray value of the dithering output, selecting an S-shaped scanning direction and a corresponding kernel function coefficient to diffuse the error according to the fact that whether the pixel is in an odd-numbered line or an even-numbered line or not, overlapping the error to a corresponding next pixel until the image of the whole grating is processed completely, obtaining a needed measured grating by defocusing and projecting the finally obtained dithering grating through a projector, obtaining a principal value phase position through a classic four-step phase shift method, unfolding the principal value phase position to obtain an absolute phase position, and finally obtaining three-dimensional information of a measured object according to a conversion formula between the phase position and height.

The invention discloses an implementation method of automatic resonance type electric power filtering and continuous reactive power compensation. When a resistant of an automatic resonance type electric power filtering and continuous reactive power compensation mixing system is designed, a medium voltage side winding equivalent impedance of a rectification transformer is equal to or approximately equal to 0, meanwhile the equivalent impedance under h harmonic frequency is equal to or approximately equal to 0 under the control of a multiple target mixture controller. By using the method, the restriction to an electric power filtering function by system impedance is eliminated, the influence caused by frequency fluctuations at an electric network side and a nonlinear load side to the electric power filtering performance can be avoided, and the high-efficiency operation of a power supply system is realized.

The invention relates to a disc-type coreless permanent-magnet synchronous motor controller based on a current inverter and a method. The disc-type coreless permanent-magnet synchronous motor controller comprises a control circuit, a three-phase inverting circuit and a step-down chopper circuit, wherein the three-phase inverting circuit is used for driving a disc-type coreless motor, and the signal input end of the three-phase inverting circuit is connected with the signal output end of the control circuit; the control signal input end of the step-down chopper circuit is connected with the signal output end of the control circuit, and the current output end of the step-down chopper circuit is connected with the current input end of the three-phase inverting circuit through an inductor L; the output shaft of the disc-type coreless motor is connected with the signal input end of the control circuit through an angle sensor; and the three-phase current outputs of the three-phase inverting circuit are respectively connected with the signal input end of the control circuit through a current sensor. The controller controls the speed regulation of the disc-type coreless permanent-magnet synchronous motor and increases the maximum speed of the motor. The controller has the characteristics of small current pulsation, good sinusoidal performance, convenience in energy feedback and the like.

The invention discloses a magnetic linkage motor of a parallel type composite excitation switch, pertaining to the field of composite excitation motors. The structure of the magnetic linkage motor comprises: a salient pole stator, an armature winding, an excitation winding and a salient pole rotor; wherein, the salient pole stator is formed by a U-shaped stator briquette and a bar-shaped permanent-magnet; an excitation coil is winded on the bar-shaped permanent magnet and a single-phase excitation winding is formed by 12 series-connected excitation coils; an integrated armature coil is winded on an adjacent U-shaped arm of the adjacent U-shaped stator briquette; and three-phase armature winding is formed. Under the condition of keeping the excitation magnetic structure of the permanent magnetic switch magnetic flux linkage motor to be unchanged, the magnetic linkage motor regulates the size of the air-gap magnetic field by introducing the electric excitation winding so as to improve the rotational speed operating range and the weakening magnet ability of the motor. The method has the advantages of high efficiency, high power density, high reliability and easy regulation on counter potential waveform sine and air-gap field and has wide application prospect.

The invention discloses a mixed SVPWM control method used for a three-phase grid-connected inverter. Based on a three-phase PWM wave controller, control is carried out according to the following three-phase PWM wave: in an alpha beta voltage vector distribution coordinate system, dividing twelve 30-degree sectors, and naming each sector with a number sequentially; defining first, fourth, fifth, eighth, ninth and twelfth sectors as a three-section type modulation sector, and commanding that a reference vector Vref which generates the three-phase PWM wave is synthesized by two basic vectors in the above six sectors; defining second, third, sixth, seventh, tenth and eleventh sectors as a five-section type modulation sector, and commanding that the reference vector Vref which generates the three-phase PWM wave is synthesized by three basic vectors in the above six sectors. According to the invention, without increasing hardware cost, through controlling a pulse width generating mode, power device switching loss can be decreased by 50% based on a present SVPWM control method.

The invention discloses a torque ripple weakening method for a concentrated winding outer rotor magnetic field modulation motor, and the method employs a method of building a target function to adjusta modulation polar coefficient combination and rotor axial segmentation for inhibition for main odd harmonics and even harmonics in the counter electromotive force of the motor. According to the method, the reduction of motor torque ripple is taken as an objective function, and an optimal modulation polar coefficient combination is obtained through a method of combining analytical calculation anda finite element method so as to suppress the influence of main odd harmonics. A rotor of the concentrated winding magnetic field modulation motor is divided into two sections in the axial direction,permanent magnets of the two sections are magnetized with N polarity and S polarity respectively, and the upper permanent magnet and the lower permanent magnet are arranged in a staggered mode by thedistance of one pole so as to restrain the influence of even harmonics. The torque ripple suppression method is easy to operate and obvious in effect, and the concentrated winding outer rotor magnetic field modulation motor has the advantages of being high in torque density and low in torque ripple.

The invention discloses a traction power supply system photovoltaic energy storage grid connecting device and a control method thereof. The method comprises detecting in real time the bus voltage and the feeder current of two power supply arms, the output power of a photovoltaic system and the charging and discharging power of an energy storage system to dynamically distribute the charging and discharging power set value of the energy storage system; computing the current set values of two four-quadrant converters to equate the internal feeder current of the two power supply arms with the sum of the phase quantity of the current of the four-quadrant converters as well as the phase of synthesized current with the voltage phase of a power system; controlling the charging and discharging power of the energy storage system to follow the set value, control the current of the two four-quadrant converter to follow the set values. Therefore, grid connection of the photovoltaic system and the energy storage system can be achieved, and meanwhile, the aim of reactive negative-sequence comprehensive compensation of a traction power supply system can be achieved.

The invention discloses a power spring power decoupling control method with an inner current loop. A power spring system comprises a bidirectional DC power supply vdc, a single-phase voltage source inverter module and an LC low-pass filter. A bypass switch S controls switching of a power spring. The power spring is in series connection with a non-critical load through a filter capacitor C and thenis in parallel connection with a critical load, and then a line impedor Z1 and a power grid vG are connected, in this way, a practical application system of the power spring is formed. The inventionprovides the power spring power decoupling control method with an inner current loop to solve problems of voltage and power fluctuation of a microgrid caused by intermittency and instability of new energy power generation. Therefore, power fluctuation of new energy power generation can be transferred to a power spring device and the non-critical load to guarantee voltage and power stability of thecritical load. Moreover, the adoption of the inner current loop makes current waveforms of the grid tend to be sinusoidal, and the system can obtain the better dynamic performance.

The invention discloses a one-phase short-circuit fault-tolerant direct torque control method for a five-phase permanent magnet motor. The one-phase short-circuit fault-tolerant direct torque controlmethod comprises the steps of: when an open-circuit fault of an A phase occurs, deducing a healthy-phase open-circuit fault-tolerant current, a fault-tolerant transformation matrix T4 / 2 and an inversematrix thereof T2 / 4 according to constraint conditions that a stator flux linkage vector is unchanged before and after the fault, a sum of healthy-phase currents is zero and the copper consumption isminimum; when a short-circuit fault of the A phase occurs, deducing a residual healthy-phase compensation flux linkage according to the principles that the stator flux linkage vector is unchanged before and after the fault and the copper consumption is minimum, or according to the constraint conditions that the healthy-phase compensation current amplitudes are equal and a sum of healthy-phase compensation currents is zero; and acquiring a stator phase voltage command through combining a stator flux linkage with a torque observer, setting torque and stator flux linkage amplitude and carrying out coordinate transformation, and combining the voltage with a pulse width modulation technology based on zero-sequence voltage injection to achieve consistent steady-state performance and dynamic performance before and after the motor short-circuit fault. The one-phase short-circuit fault-tolerant direct torque control method has the advantages of constant switching frequency of an inverter and small CPU overhead.

The invention discloses a non-AC voltage sensor control method of a grid-connected inverter. The non-AC voltage sensor control method of the grid-connected inverter is characterized by comprising the following steps of: collecting three-phase grid-connected current iabc and DC bus voltage udc in real time, observing power grid side AC voltage ealphabeta by an AC voltage observer and calculating reactive power Q; obtaining an active current instruction as shown in the specification and a reactive current instruction as shown in the specification, obtaining three-phase SPWM modulation signal as shown in the specification and modulating the three-phase SPWM modulation signal as shown in the specification; generating a switching signal Sa,b,c of driving the inverter and controlling on or off of a switch tube through the switching signal of driving the inverter, thereby achieving control on the inverter. On or off of the switch tube is controlled through the switching signal of driving the inverter, so that the control on the inverter is achieved; the AC voltage observer is constructed by applying a TOGI-OSG; the hardware cost is reduced; the power grid adaptability of the inverter under the distributed energy access condition is improved; the problems of an integral initial value, integral saturation and DC bias in the observation process are solved, and due to the filtering effect of a TOGI, the sine degree of the grid-connected current is good and the harmonic content is low.

The invention discloses a novel topology of an electric spring and a control method of the novel topology. Along with increase of grid connection capacity of renewable energy power generation of wind energy, solar energy and the like, the stability of a power system faces a severe test; and when large-scale distributed grid connection of renewable energy power generation is carried out, the probability that a power grid, particularly a micro grid is broken down is gradually increased, so that the electric spring is provided primarily aiming at the instability of renewable energy power generation in the micro grid. According to the novel electric spring topology structure and control strategy provided by the invention, the stability of critical load voltage can be ensured; fluctuation of input voltage can be transferred to non-critical load; and the condition that the energy consumption of the non-critical load is kept in accordance with the change trend of the input voltage can also be ensured. The monotonous change relationship between the active power and the input voltage realized by the novel topology cannot be realized by an existing electric spring, so that the novel topology of the electric spring has relatively high practicality when the amplitude of the voltage increases along with increase of generation power.

The invention relates to a high-power density permanent magnet motor belonging to the field of motors. The invention solves the problems of low efficiency and thrust density, large thrust fluctuation and high vibration and noises of the traditional double-edge ironless straight line permanent magnet synchronous motor, which are caused by low air gap magnetic density and poor sine degree of air gap magnetic density wave forms. An air gap is positioned between a primary pole and a secondary pole of a straight line motor; main permanent magnets and isolated magnets are sequentially arranged on the inner wall of a yoke plate at intervals; the inner sides of the main permanent magnets are provided with assembling magnets which have same widths along a motion direction; the inner sides of the isolated magnets are provided with auxiliary permanent magnets which have same widths along the motion direction; the outer side surfaces of m auxiliary permanent magnets and m assembling magnets are positioned on a same plane; the main permanent magnets are parallelly magnetized in magnetizing directions perpendicular to the motion directions of active cells, and every two adjacent main permanent magnets are in reverse magnetizing directions; the auxiliary permanent magnets are parallelly magnetized in the magnetizing directions parallel to the motion directions of the active cells, and every two adjacent auxiliary permanent magnets are in reverse magnetizing directions.

The invention discloses an H-bridge cascading STATCOM dead-beat control method based on a discrete state observer and a discrete sliding-mode observer, and relates to the H-bridge cascading STATCOM control technology. The H-bridge cascading STATCOM dead-beat control method aims to solve the problem that an existing dead-beat control method must be matched with a good reference current prediction method and a common prediction method needs to be dependent on an accurate mathematical model, so that the existing dead-beat control method is seriously limited in actual application. According to the H-bridge cascading STATCOM dead-beat control method, the discrete state observer is constructed according to a simple mathematical model of an H-bridge cascading STATCOM, and a reference instruction current at a k+1 moment is obtained by means of calculation at a k moment by adopting the prediction function of the discrete state observer, so that dead-beat control is realized in a true sense; the discrete sliding-mode observer is constructed for conducting real-time observation on ud (k) and uq (k) of three-phase voltage values output by the STATCOM under a dq coordinate system. The H-bridge cascading STATCOM dead-beat control method based on the discrete state observer and the discrete sliding-mode observer is applied to reactive compensation and harmonic wave filtering of a power grid.

The invention discloses a yoke-free closed slot type multi-plate permanent magnet motor comprising a motor housing, a plurality of rotors, and a plurality of stators. The motor housing consists of a rotating shaft, a bearing, a front end cover, a rear end cover and a casing; the plurality of rotors are fixed with the rotating shaft; and the stators are arranged among the adjacent rotors. Each stator has a yoke-free closed slot structure formed by two stator outer teeth, a stator inner tooth between the two stator outer teeth, a stator inner plug, a stator outer plug, and a winding. Each rotor with a combined oblique pole structure includes a plurality of rotor plates that are distributed coaxially at intervals along the axial direction and fan-shaped permanent magnets contacted to the rotor plates. According to the invention, the provided yoke-free closed slot type multi-plate permanent magnet motor has advantages of improved slot full rate, iron core material saving, torque quality improvement, torque density enhancement, and improvement of whole operation efficiencies of the low speed and light load.