35results about How to "Improve weak magnetic properties" patented technology

The invention discloses a variable-speed permanent-magnet alternator system and a double-port voltage stabilization control method therefor. The system comprises a permanent-magnet alternator, a PWM (Pulse Width Modulation) rectifier, a DC filtering device and a controller, wherein the controller comprises a rotor position and rotational speed detection module, a DC voltage detection module, a DC current detection module, an AC voltage detection module, an AC current detection module, a coordinate transformation module, a first regulator, a second regulator, a current limit module and a PWM generating module. The method provided by the invention comprises the following steps: acquiring the position, the rotational speed, the DC voltage and current, and the AC voltage and current of the alternator rotor; and acquiring the quadrature-axis and direct-axis currents through coordinate transformation, so as to stabilize the DC and AC voltages for setting values and achieving amplitude limit to quadrature-axis and direct-axis currents generated by a target subjected to closed-loop control and generate PWM trigger pulses to control the PWM rectifier. By adopting the invention, double-port voltage stabilization of a DC and AC output terminal is maintained when the rotational speed of the alternator changes, the cost is low and the reliability is high.

The invention provides a vehicle built-in permanent magnet synchronous motor controlling method. The method comprises steps of 1, establishing permanent magnet synchronous motor mathematic models including a voltage equation model, an electromagnetic torque equation model and a torque balance equation model; 2, designing a sliding mode surface and a sliding mode control law, so as to achieve sliding mode control of the electromagnetic torque of a motor; 3, based on the electromagnetic torque value Te, performing decomposition to obtain a quadrature-axis current iq and a direct-axis current id; 4, based on iq, id, Udc, quadrature-direct axis voltage references U'q and U'd, obtaining quadrature-direct axis current reference values i<*>[q] and i<*>[d] by decomposition; 5, decomposing i<*>[q] and i<*>[d] to obtain the quadrature-direct axis voltage references U'q and U'd; and 6, based on the U'q and U'd, obtaining two phase stationary voltages U[alpha] and U[beta] by coordinate conversion, taking the U[alpha] and U[beta] as the input, and obtaining three phase reference voltages Ua, Ub and Uc after modulating the models to drive an inverter and the motor to work. The control method can ensure stable operation of the motor under any working condition.

The invention discloses a disc type motor rotor with a pole shoe composite magnetic pole structure, and relates to the field of motors. The disc type motor rotor comprises a rotor supporting disc, a hole is formed in the center of the rotor supporting disc, and a groove is formed in the surface of one side of the rotor supporting disc and used for installing a rotor core and composite magnetic poles; the rotor iron core is of an annular structure, is arranged at the bottom of the groove and is tightly attached to the rotor supporting disc, T-shaped baffles distributed in the radial direction are arranged on a surface of a side, away from the rotor supporting disc, of the rotor iron core, and the T-shaped baffles divide the rotor iron core into a plurality of fan-shaped spaces at equal intervals along the circumference; the composite magnetic poles are arranged in the fan-shaped spaces on the rotor iron core; the composite magnetic poles comprise permanent magnets and pole shoes, and the pole shoes made of composite soft magnetic materials are installed on the surface of the permanent magnet. The radians of the pole shoes on the surface of the permanent magnet can be adjusted, sinewave air gap flux density is generated, the output torque of a motor is smooth, the pole shoes can protect the permanent magnets against field loss under the action of a demagnetization field, the field weakening capacity of the motor is improved, and the motor is easy to machine and suitable for batch production.

The invention discloses a split type combined permanent magnet brushless motor for an electric vehicle. A rotor is coaxially positioned in the internal of a stator; a rectangular neodymium iron boron permanent magnet steel and two same rectangular ferrite permanent magnet steels are fixedly embedded in each pole of the rotor; the neodymium iron boron permanent magnet steels are close to air gaps and are symmetrical relative to the central line of the rotor poles; the two ferrite permanent magnet steels are close to a rotation shaft, are distributed on the two sides of the central line of the rotor poles and are symmetrical relative to the central line of the rotor poles; a magnetic conductive bridge is between the two ferrite permanent magnet steels; the permanent magnet steel on each pole is magnetized along the tangential direction of the circumference; the magnetizing directions on the same pole are the same, and the magnetizing directions on the adjacent two poles are opposite; the rare earth permanent magnet material and the non-rare-earth ferrite permanent magnet material are adopted at the same time; on the basis of ensuring the power density and the torque density of the permanent magnet motor with a small amount of rare earth, the cost of the motor is reduced by more than 50%; and in addition, the requirements on the torque and the power in the electric vehicle applications can be met on the premise of keeping the relatively high power density and the torque density.

The invention discloses a stator yoke-free axial flux permanent magnet motor comprising a stator, a first rotor and a second rotor which are coaxial. The first rotor and the second rotor are symmetrically arranged on the two sides of the stator. The first rotor and the second rotor respectively comprise a hollow annular first rotor core and a second rotor core which are used for coaxially connecting with a rotating shaft. The first rotor core and the second rotor core are alternately provided with permanent magnets and soft magnets along the circumference toward the end face of the stator. Theratio of the pole-arc coefficient of the permanent magnets to the soft magnets is greater than 1. The permanent magnets and the soft magnets on the different rotors of the two sides of the stator arearranged diagonally. According to the stator yoke-free axial flux permanent magnet motor, the flux weakening capability and the utilization ratio of the permanent magnets can be enhanced, the coggingtorque and the axial magnetic tension can be reduced and the bearing of the motor can be protected to a certain extent by using the diagonal alternating rotor structure with unequal pole-arc coefficient.

The invention discloses a Halbach array permanent magnet synchronous motor with high flux weakening property. The Halbach array permanent magnet synchronous motor structurally comprises a stator iron core, a three-phase armature winding, an air gap, a rotor iron core, a sectional Halbach array permanent magnet pole, and the like. The Halbach array permanent magnet synchronous motor has the advantages that the problem of difficulty in flux weakening in the traditional surface-mounted permanent magnet synchronous motor is solved; by additionally arranging a rotor iron core convex pole on a direct axis, the length of the air gap of the direct axis is effectively reduced, the reactance of the direct axis of the armature is increased, the flux weakening effect of the armature current is enhanced, and the irreversible demagnetizing of the permanent magnet in the demagnetizing magnetic field is avoided; the surface-mounted magnetic pole adopts the sectional Halbach array structure, so that the distribution of the air gap magnetic field is improved, the problems of overlarge torque fluctuating and the like due to the rotor convex pole are relieved, and the property of the whole motor is improved.

The invention provides a 12-slot 10-pole permanent-magnetic brushless motor. A rotor is provided with 20 slot wedges. 20 magnetic steel sheets are installed among the slot wedges. Each of the magnetic steel sheets is of a V-type embedded structure. Each V-type unit is formed by two adjacent magnetic steel sheets. 10 V-type units are uniformly distributed around the rotor. Polarity of two faces, arranged in the corresponding V-type opening, of the magnetic steel sheets is the same and each V-type opening is towards the surface of the rotor. The polarity of the opening of each V-type unit is different from that of openings of adjacent two V-type units. The thickness of each magnetic steel sheet is 3.0+/- 0.01mm. According to the invention, steel faces can be protected; demagnetizing resisting ability of the brushless motor is improved; stable operation life of the motor is prolonged; high-speed performance of the motor is improved; flux weakening ability of the motor is effectively improved; and constant-power operation range of the motor is extended.

The invention provides a high-strength magnetic-gathering permanent-magnet rotor according to the problem of limitation of overload capacity and rotor strength of an existing built-in tangential permanent-magnet motor. The high-strength magnetic-gathering permanent-magnet rotor comprises a rotor core and a permanent magnet, wherein a plurality of permanent-magnet grooves are uniformly formed in the rotor core along a circumferential direction, the permanent-magnet grooves are arranged along a direction of a rotation shaft in a penetrating way, adaptive tangential permanent magnets are arrangedin the permanent-magnet grooves, linear grooves are formed in the rotor core at intervals along a circumferential direction, the linear grooves are arranged along the direction of the rotation shaftin a penetrating way, linear permanent magnets are arranged in the linear grooves, at least two linear grooves arranged in a straight line way and two of the linear permanent magnets are arranged between two adjacent permanent-magnet grooves. A light and high-strength alloy material is embedded to an inner side of the rotor core, the rotor weight is reduced, and the rotor strength is improved. Thehigh-strength magnetic-gathering permanent-magnet motor has the characteristics of high overload capability, high rotor strength, high power density, high modular degree and the like and is suitablefor application occasions such as an aviation permanent-magnet starting power generation system.

The invention discloses a permanent magnet motor and a compressor. The permanent magnet motor comprises a stator and a rotor. The stator comprises a stator core, a plurality of coil groups, and two motor lead groups. Each coil group comprises a plurality of coils which are coiled on stator bulging teeth. Each coil group comprises an incoming line terminal and a leading-out terminal formed by joints in the same number. Each motor lead group has a plurality of joints used to connect with the coil groups, and a motor lead of a motor control circuit. An inverter with a control algorithm provides power input for the permanent magnet motor. An effective value Um of maximum voltage between terminals, provided to the permanent magnet motor by the inverter, and no-load back EMF ke value between motor line terminals satisfy 4<=Um/ke<=56, wherein unit of Um is volt, unit of ke is volt/thousand round per minute. The permanent magnet motor can also satisfy torque output capacity of a motor in high-frequency.

The invention relates to the technical field of a driving motor, and particularly provides a weak flux control method and device and a motor. The weak flux control method comprises the steps of acquiring an output value of a q-axis voltage and a setting value of the q-axis voltage under a weak flux state; determining a compensation value of a weak flux current according to the output value and thesetting value; and compensating the weak flux current according to the compensation value. According to the control method, the weak flux effect of the motor is improved by correction and compensation on the weak flux current on the basis of an existing weak flux method, the rotational speed of the motor is further improved, the rotational speed is higher compared with existing weak flux speed rising, the driving performance of the motor is improved, and more demand scenes are met.

The invention discloses an iron core and a disk type motor. Multiple groups of magnetic steel mounting sites are distributed on the iron core along the circumferential direction of the iron core uniformly; each group of magnetic steel mounting sites comprises a plurality of steel tanks; along the circumferential direction of the iron core, first iron core teeth are arranged between the adjacent steel tanks of the same group of the magnetic steel mounting sites; the steel tanks of the same group of magnetic steel mounting sites are used for mounting magnetic steel with the like magnetic pole; second iron core teeth are arranged between the adjacent group of magnetic steel mounting sites; and the steel tanks of the adjacent group of magnetic steel mounting sites are used for mounting magnetic steel with opposite magnetic poles. Each group of magnetic steel mounting sites comprises a plurality of steel tanks, and the same group of steel tanks are partitioned by the first iron core teeth along the circumferential direction of the iron core, so that the d-axis inductance is enhanced. When the motor performs weak magnetic control at high speed, the size of the needed current can be obviously reduced under the same voltage when the d-axis inductance of the motor is increased, or the highest weak magnetic rotating speed which the motor can reach to can be significantly increased.

The invention discloses an optimal field weakening control method based on the safety of a spring electric rudder system. The method comprises detecting current motor speed and load torque, obtainingthe output torque at the current speed, Current limit, d-axis inductance component and q-axis inductance component, defining a weak magnetic index J, giving the optimal weak magnetic control index based on rotational speed, output torque and load torque, calculating the J value of d-axis current component under different values, selecting the maximum value maxJ of J value, and taking the d-axis current component and q-axis current component corresponding to the value as the control output under the current rotational speed. Aiming at the characteristics of tactical missile, such as no reuse, fast maneuver, complex working condition and short endurance time under the same working condition, the invention fully utilizes the weak magnetic rising speed capability of the missile electric actuator under the condition of surplus power, designs the optimal distribution strategy of the straight axis current and the numerical calculation scheme, thereby improving the weak magnetic performance ofthe missile electric actuator system.