13results about How to "Increase sine" patented technology

The invention discloses a three-phase alternating-current motor low-harmonic winding design method, which comprises the following steps of: determining the equivalent slot number qe of each pole and each phase of a three-phase low-harmonic winding according to basic parameters of a motor, dividing an area in an iron core slot of the motor into an upper layer, a middle layer and a lower layer, placing a phase coil of the three-phase winding in a single layer, and determining a phase belt distribution table and a winding connection diagram of the winding; according to the principle that slot current is distributed along the surface of an iron core in a sine mode, the numerical relation of the number of turns of all coils in a phase belt is determined, the turn ratio of all the coils is n1: n2: n3... nqe, the symmetry axis of slot electromotive force in the phase belt is determined, the electrical angles of slot electromotive force phasors relative to the symmetry line are respectively alpha1, alpha2, alpha3... alphaqe, and the range of the number of effective series turns of each phase meeting the motor performance is determined; in consideration of the design principle of the minimum harmonic magnetic potential and the limited slot filling rate, the actual number of turns of the coil in the phase belt is N1, N2, N3... Nqe. According to the invention, the third harmonic electromotive force amplitude of each phase of the motor is reduced, and the motor efficiency is improved.

The present application provides a motor rotor, a reluctance motor and an electric vehicle. The motor rotor comprises a rotor core (1), the rotor core (1) comprises an inner ring portion (2) and an outer ring portion (3), the inner ring portion (2) is provided with a plurality of magnetic barrier groups along the circumferential direction, each magnetic barrier group comprises at least two inner magnetic flux barriers (4) arranged at intervals along the radial direction, an inner magnetic conduction channel (5) is formed between two adjacent inner magnetic flux barriers (4), the outer ring portion (3) is provided with a plurality of outer magnetic flux barriers (6) arranged at intervals along the circumferential direction, an outer magnetic conduction channel (7) extending along the radial direction is formed between adjacent outer magnetic flux barriers (6). According to the motor rotor of the present application, the air gap waveform of the reluctance motor can be changed, the waveform can be optimized, the sinusoidal degree can be increased, the motor efficiency can be improved, and the motor torque pulsation can be reduced.

The invention relates to a stable and reliable food processor which comprises a permanent magnet direct current brushless motor, the motor comprises a stator and a rotor, the rotor comprises a rotor iron core and a permanent magnet, the inner side of the outer edge of the rotor iron core is provided with an installation groove for the permanent magnet to be inserted, and the position, opposite to the permanent magnet, of the outer edge of the rotor iron core is provided with a rotor salient pole protruding outwards. A groove is formed between every two adjacent rotor salient poles, the rotor further comprises a fixing cage which is arranged outside the rotor iron core and integrally formed, the fixing cage comprises end plates located at the two ends of the rotor iron core and fixing columns located on the outer side wall of the rotor iron core and connected with the end plates at the two ends, the fixing columns are located at the grooves, and the outer diameter of the fixing columns is not larger than that of the rotor salient poles. The fixing cage is provided with the fixing columns at the grooves to integrally wrap the rotor, the strength of the fixing cage is increased, the rotor iron core and the permanent magnets are fixed and limited, and the situation that the strength of the fixing cage is affected due to the fact that the periphery bears large centrifugal force when the fixing cage is fixedly connected only through the connecting column in the center and deforms is avoided.

A method for compensating installation errors of Hall sensors in a permanent magnet synchronous motor under disordered sequence includes the following steps: by energizing the three-phase stator windings in sequence and presetting a certain time, the back electromotive force of each phase is measured; the position of the rotor is obtained according to the back electromotive force value of each phase obtained in step 1; the value of the Hall sensor transferred to the corresponding sector is measured by injecting a fixed SVPWM, and the correct order of the Hall sensor is determined by the values ​​of the six groups of Hall sensors in step 3; when the motor starts normally, the position deviation of the Hall sensor is compensated. This method solves the problem that the Hall signal detects a rotor position that is inconsistent with the actual position due to the disordered sequence of the Hall sensor of the motor, and the rotor cannot be transferred to the corresponding sector and cannot start normally; through the position deviation compensation method of the Hall sensor, the sinusoidality of the current can be improved, the position deviation of the Hall sensor can be reduced, and the harmonic content of the current can be reduced.

The application relates to a rotor assembly, a rotor structure and a motor, the motor comprising a stator structure and a rotor structure, the rotor structure being formed by rotationally stacking an even number of rotor assemblies, the rotor assembly comprising a rotor core and a magnetic tile, the rotor core comprising an outer convex circular arc part and an inner concave circular arc part, a plurality of outer convex circular arc parts and a plurality of inner concave circular arc parts being arranged in sequence and staggered along the circumference of the rotor core, a magnetic tile being attached to each inner concave circular arc surface, and adjacent outer convex circular arc parts and magnetic tiles forming a pair of magnetic poles; the magnetic tile and the inner concave circular arc surface need to satisfy:;; the adjacent outer convex circular arc parts and the magnetic tile form a pair of magnetic poles, compared with the pair of magnetic poles using two magnetic tiles, the number of magnetic tiles used is effectively reduced; the angle of the inner concave circular arc surface and the outer convex circular arc surface and the width of the magnetic tile are limited, so that the area of the outer convex circular arc part is larger than the area of the magnetic tile, the width of the magnetic tile is reduced, the width of the magnetic tile is not too small, the volume of the magnetic tile is reduced, and the amount of permanent magnet material is reduced.

The invention discloses a rotor punching sheet and a permanent magnet motor thereof, the rotor punching sheet comprises a sheet body and even number of synthetic magnetic poles, and the even number of synthetic magnetic poles are distributed on the sheet body along the circumferential direction; an arc corresponding to the outline of the outer circle of each combined magnetic pole and the shaft hole of the sheet body are eccentric, and a first notch and a second notch which are concave inwards are formed in the two ends of the arc respectively and are symmetrical about the midpoint of the arc. The arcs of the outer circle outlines of the combined magnetic poles are eccentric to the rotor shaft hole, and each arc is provided with the first notches and the second notches which are symmetrically distributed, so that uneven air gap distribution which is in a specific shape and is in a certain regular size is formed, which is equivalent to that very ingenious pole cutting treatment is performed on the rotor; the sine degree of air gap flux density can be optimized, the effects of weakening harmonic waves of all orders and reducing cogging torque are achieved, and vibration and electromagnetic noise are reduced while the efficiency of the motor is improved.

The present invention proposes a method for measuring the alternating current magnetic properties of magnetic materials by improving the sinusoidality of the magnetic polarization intensity waveform, which belongs to the technical field of magnetic material magnetic property measurement. It can solve the technical problems that the method of improving the sinusoidality of the magnetic polarization intensity waveform through a programmable input power supply is difficult to ensure that a good measurement effect is maintained at different measurement points, the measurement process takes a long time, and it is difficult to achieve ideal measurement conditions. The technical scheme includes the following steps: measuring the current value of the primary coil, and obtaining the frequency, angle and third harmonic current angle of the fundamental current; measuring the induced voltage value of the secondary coil, and obtaining the virtual axis induced voltage value of the secondary coil; extracting the harmonic components in the induced voltage of the secondary coil; calculating the third harmonic voltage value that needs to be compensated in the primary coil input voltage, and outputting it through a programmable power supply. The present invention can be applied to improving the sinusoidality of the magnetic polarization intensity waveform in the measurement of the alternating current magnetic properties of magnetic materials.

The invention provides a control method of a power conversion circuit, power conversion equipment and a power supply system. The control method comprises the following steps: acquiring a real-time alternating-current voltage on a second end of the secondary bridge circuit, and when the real-time alternating-current voltage is in a preset transition region of a voltage zero crossing point, controlling each switching tube in the secondary bridge circuit to perform on-off action within secondary switching time so as to enable the secondary bridge circuit to perform power conversion; and when the real-time AC voltage is in the preset transition region of the voltage zero crossing point, controlling a part of switch tubes in the secondary side bridge circuit to be switched on within the secondary side dead zone time, so that the secondary side bridge circuit and the secondary side of the transformer form a follow current loop. By means of the method, the power conversion circuit is not prone to generating current oscillation near the voltage zero crossing point, and therefore overstress damage of a secondary side switch tube can be avoided, and the current waveform can be optimized.

The invention provides a rotor structure and a motor. The rotor structure comprises a rotor body and a plurality of magnetic bodies. The rotor body comprises a rotor yoke part and a plurality of rotor salient poles, the rotor salient poles are arranged on the outer circumferential surface of the rotor yoke part, and the plurality of rotor salient poles are arranged at intervals along the circumferential direction of the rotor yoke part; a mounting groove is formed between every two adjacent rotor salient poles; the magnetic bodies are arranged in the mounting grooves, and the plurality of magnetic bodies and the plurality of rotor salient poles are alternately arranged; grooves are formed in the side faces, making contact with the magnetic bodies, of the rotor salient poles. The motor comprises the rotor structure. The grooves are formed in the side faces, making contact with the magnetic bodies, of the salient poles of the rotor, magnetic leakage can be reduced, the sine degree of air gap flux density can be improved, the use amount of the magnetic bodies is reduced, meanwhile, counter electromotive force is effectively improved, the harmonic content of the counter electromotive force is reduced, and the operation performance of the motor can be improved, such as torque pulsation and noise reduction.

The embodiment of the invention provides an addition transformer, and relates to the technical field of electronic power. The addition transformer comprises a plurality of annular conductors; the multiple groups of input windings are in one-to-one correspondence with the annular conductors, and the annular conductors penetrate through the first axial cavities of the input windings; and the plurality of annular conductors all penetrate through the second axial cavity of the output winding, and the plurality of annular conductors are not intersected with one another. According to the adder provided by the embodiment of the invention, the performance of the adder transformer is improved from multiple dimensions such as capacity expansion, multi-stage voltage output providing, current / voltage ratio flexible adjustment, waveform optimization, voltage harmonic reduction and the like, the power supply requirements under multiple working conditions are met, and reliable electric energy conversion is provided for various high-power alternating-current transmission devices.

The present application relates to a current sharing method for a centralized control interleaved parallel circuit, comprising setting a duty cycle of a first parallel circuit in the interleaved parallel circuit as a first duty cycle, setting a duty cycle of a second parallel circuit in the interleaved parallel circuit as a second duty cycle; setting a second duty cycle compensation quantity for ensuring that currents of the two parallel circuits are equal at the end of one switching cycle based on a ratio between a bus voltage value of the interleaved parallel circuit and a voltage difference between a first duty cycle, an input voltage sampled at a zero-crossing point of a triangular carrier of the first parallel circuit and an input voltage sampled at a period value. The present application also relates to a computer readable storage medium and a centralized control interleaved parallel circuit. The present application can solve the problem of uneven current among circuits in a low-cost and easy-to-implement manner, and improve the sinusoidal degree of the second parallel circuit.

The invention discloses a position-sensorless control method based on an improved full-order sliding-mode observer, and relates to the technical field of motor control. Three-phase current is sampled and subjected to 3 / 2 conversion, and stator voltage is input into the observer; constructing a full-order sliding mode observer by taking the two-phase current and the two-phase counter electromotive force of the stator as state variables; designing a sliding mode surface based on the stator two-phase current error; designing a current control law and a back electromotive force control law; the convergence proof of the full-order sliding mode observer is improved; on the premise that convergence is met, the two opposite electromotive forces are observed and input into a phase-locked loop, and the estimated electrical angle and the estimated electrical angular speed of the rotor can be obtained. For a surface-mounted permanent magnet synchronous motor, on the basis of a full-order sliding mode observer, high-order terminal sliding mode control is introduced, so that the control precision of a position sensorless can be effectively improved.

This invention provides a rotor and a motor. The rotor (10) has multiple permanent magnet slots (11). Any two adjacent permanent magnet slots (11) are symmetrical about a second center line (2). The outer contour of the rotor (10) between any two adjacent second center lines (2) is symmetrical about a first center line (1), and includes: a first arc segment (101) located in the middle, two second arc segments (102) extending outward from both ends of the first arc segment (101), two transition segments (103) extending outward from the two second arc segments (102), and two third arc segments (104) extending outward from the two transition segments (103); the center and radius of the second arc segments (102) are different from those of the first arc segment (101). The rotor of this invention reduces torque pulsation and improves motor efficiency without increasing manufacturing difficulty and cost.