50results about How to "Reduce output torque ripple" patented technology

The invention provides a four-phase doubly salient motor, which belongs to doubly salient motors. The four-phase doubly salient motor consists of a stator and a rotor which are arranged around the same rotating shaft; 8n salient teeth are uniformly distributed on the stator; exciting windings are embedded or permanent magnet steel is arranged in slots at every four salient teeth on the stator; centralized armature windings are sleeved on the salient teeth of each stator respectively; the armature windings on the salient teeth at the same position in a magnetic field are connected in series with one another to form a one-phase winding; and 6n rotor poles are uniformly distributed on the rotor, wherein n is a positive integer and more than or equal to 1. A motor unit has an 8/6 structure. The polar distance of the stator is triple the arc length of a stator pole; and the rotor pole is as wide as the stator pole. When the rotor poles are widened until the polar arc coefficient is 1/3, the output power is maximum when the motor is used as a generator. Compared with a three-phase 6n/4n polar doubly salient motor, the four-phase doubly salient motor has higher power density, lower winding copper loss, wider speed regulation range and smaller torque pulse.

The invention discloses a control method of a self-balancing man-riding electric unicycle. The method includes: acquiring data from an accelerator and a gyroscope disposed on the unicycle, subjecting the acquired data to Kalman filtering to obtain current tilt angle and tilt angular velocity of the unicycle, acquiring a given motor speed value through a nonlinear PD (proportional plus derivative) controller, acquiring a given torque current value from a difference between the given motor speed value and a currently measured motor speed fed-back value through a PI (proportional plus integral) controller, acquiring a drive signal through vector control, and allowing a motor to output a proper torque to keep the unicycle balanced. The control method has the advantages that a control strategy features good dynamic and static properties, system vibration and noise are reduced, and the unicycle is allowed to self-balance the attitude and to carry a man riding.

The invention discloses a method for reducing the torque ripple of a five-phase embedded permanent magnet motor. According to the invention, a stator magnetomotive force model is established. An equivalent magnetic circuit diagram of the motor is extracted, and an odd harmonic part in the rotor magnetomotive force is converted into an even harmonic part according to the interaction principle between the stator magnetomotive force and the rotor magnetomotive force of the motor. In this way, the permanent magnet torque ripple is reduced. Meanwhile, an optimal extreme arc coefficient ratio underthe condition of an asymmetric magnetic pole structure is solved. On the basis of the asymmetric magnetic pole structure, the repeated units of a permanent magnet magnetic pole are determined. The angle of one-time offset is calculated, and a proper offset method is selected for carrying out the magnetic pole deviation. The performances of the reluctance torque and the cogging torque are reduced.According to the invention, the equivalent magnetic circuit method is used for analyzing and calculating an optimal extreme arc coefficient. Not only the optimal permanent magnet torque performance isobtained, but also the design period is shortened. By adopting the magnetic pole offset method, the pulsation of the output torque of the embedded motor is further reduced.

The invention discloses a stator/rotor permanent magnetic type magnetic-flux-variable axial magnetic flux switching permanent magnetic generator. The generator comprises a first rotor, a first stator,a second rotor, a second stator and a third rotor which are installed coaxially in order, the first rotor and the third rotor are symmetric by taking the second rotor as the center, the first statorand the second stator are symmetric by taking the second rotor as the center, and each of the rotors and stators is of a salient pole structure. An aluminum-nickel-cobalt permanent magnet is low in acoercive force, so that different pulse currents are applied to change the magnetization magnitude and direction of the aluminum-nickel-cobalt permanent magnet, the magnetization level of the permanent magnet can be changed and memorized, and an air gap magnetic field of a motor can be controlled flexibly by adjusting the directions and magnitudes of the pulse currents. In addition, a pulse winding only applies a magnetizing/demagnetizing current in a very short time, there is nearly no exciting copper loss, and the problem that the power or torque density of an existing axial variable magnetic flux switching permanent magnetic generator is not high enough is solved.

The invention discloses a low-torque ripple sensorless control method for a synchronous reluctance motor, and belongs to the technical field of motor control. The invention aims to solve the problemsof high-frequency torque pulsation and noise pollution of a direct-axis high-frequency signal injection method used at a zero low speed in the position sensorless control of a conventional synchronousreluctance motor. The method comprises the following steps: simultaneously injecting predetermined high-frequency pulse voltages with the same phase and fixed amplitude proportion into a dq shaft system of the synchronous reluctance motor; obtaining a rotor position estimation error based on the extracted three-phase pulse current in the abc three-phase shaft system of the synchronous reluctancemotor; further obtaining a rotor estimation position and a rotor estimation rotating speed which are used for closed-loop control of the motor; and performing calculating to obtain q-axis compensationcurrent, and compensating for the q-axis current of the motor, so the actual rotating speed of the rotor better tracks the given rotating speed of the rotor, and the output torque ripple of the synchronous reluctance motor is reduced. According to the invention, the output torque ripple of the synchronous reluctance motor can be reduced on the basis of realizing sensorless control.

The invention belongs to the field of mining hydraulic motors, and especially discloses a same-distribution-angle hydraulic cylinder motor. A technical problem to be solved is providing a same-distribution-angle hydraulic cylinder motor with the advantages of simple structure, operation convenience, high safety coefficient, long service life and effective reduction of the coal mine underground accident rate. The motor comprises a case body, three hydraulic cylinders, a crankshaft, a case body front end assembly and a control system, the whole case body is a shell structure, the three hydraulic cylinders are arranged in the case body side by side, the front end of the case body is provided with a case body semicircle seat for installing the crankshaft, the case body front end assembly is fixedly connected with the case body to fix the crankshaft, the piston terminals of the hydraulic cylinders are connected with the crankshaft through piston terminal covers, the hydraulic cylinders move back and forth to drive the crankshaft to rotate, the crankshaft drives the control system to move, and the control system controls the reciprocating motion of the three hydraulic cylinders in order to drive the crankshaft to continuously revolve. The motor adopting the hydraulic cylinders to drive the crankshaft to rotate has the advantages of low rotating speed, large torque, and suitableness for the use requirements of coal mine underground equipment.

The invention discloses a virtual polarity fractional-slot concentrated winding spoke type permanent magnet motor and a torque ripple inhibition method thereof. A novel spoke type permanent magnet synchronous motor which is provided with a virtual polarity and is in hybrid connection with a star triangular winding is provided. The torque ripple of the motor is reduced by reducing stator and rotorharmonic orders respectively on the basis of determining the stator and rotor magnetomotive force harmonic orders influencing the torque ripple. The specific process comprises the step of determiningthe harmonic orders of rotor gap flux density influencing the torque ripple according to the relation that the rotor gap flux density is in direct proportion to rotor magnetomotive force. 11-th and 13-th harmonics in rotor magnetomotive force are eliminated by using unequal pole-arc coefficients, so that 12-th harmonics of torque ripple are eliminated. And then, 5-th, 7-th, 17-th and 19-th harmonics in stator magnetomotive force are eliminated by using the hybrid connection of the star triangular winding, so that 6-th and 18-th harmonics of torque ripple are eliminated, and the purpose of reducing the torque ripple integrally is reached.

The invention discloses a method for reducing torque ripples of a continuous pole permanent magnet synchronous motor, which specifically comprises the steps of firstly, determining the harmonic orderof the rotor magnetomotive force affecting the torque ripples starting from the principle of the generation of the torque ripples; then determining the harmonic order of the rotor air gap flux densityaffecting the torque ripples according to a relation that the rotor air gap flux density is in direct proportion to the rotor magnetomotive force; deducing a formula of the angle difference of unequal continuous pole permanent magnet pole-arc coefficients for weakening the main harmonic order of the specific torque ripple through deducing the Fourier expression of the rotor air gap flux density in the cases of equal continuous pole permanent magnet pole-arc coefficients and unequal continuous pole permanent magnet pole-arc coefficients; and furthermore, reducing the primary main harmonic waves of the torque ripples through the peak-valley cancellation generated by the unequal pole-arc coefficients between the torque ripples so as to achieve the purpose of reducing the overall torque ripples. Therefore, the method has high permanent magnet utilization rate and low torque ripples under the condition of ensuring that the average output torque of the motor is almost unchanged.

The invention relates to an electric wheel mining dump truck, in particular to a power control system of a new energy electric wheel mining dump truck. The defects and problems existing in an electricwheel mining dump truck which adopts a diesel generator set to provide power are solved. The power control system of the new energy electric wheel mining dump truck comprises a lithium battery, a hydrogen fuel cell engine, a direct-current bus, a first DC/DC triple chopper, a second DC/DC triple chopper and a third DC/DC triple chopper, wherein the lithium battery and the hydrogen fuel cell engine are respectively connected in parallel with the direct-current bus; the first DC/DC triple chopper takes power from the direct-current bus and supplies power to an armature winding of the first DC motor; the second DC/DC triple chopper takes power from the direct-current bus and supplies power to the armature winding of the second DC motor, and the third DC/DC triple chopper takes power from thedirect-current bus and supplies power to the excitation windings of the first DC motor and the second DC motor. The power control system adopts a hydrogen fuel engine and lithium battery hybrid energy system to replace the diesel generator set to provide power.

The invention discloses an asymmetrical excitation stator alternate-angle dual-salient-pole motor and a control method thereof, and belongs to the technical field of direct-current motors. The motor comprises a motor revolving shaft, a magnetic conductive material, a central electric excitation coil, two groups of salient pole stators, two groups of salient pole rotors and a stator winding, wherein four salient pole teeth are distributed on the rotors; six salient pole teeth are distributed on the stators; a second group of salient pole stators is staggered away from a first group of salient pole stators by a mechanical angle of 30 degrees; the stator winding is partitioned into a phase A, a phase B and a phase C; and the phases A, phases B and phases C of the salient pole stators on two sides are arranged in a staggered way. The method comprises the following steps: selecting a powered-on winding according to positions of the rotors; rotating the motor after powering on; performing phase change when a rotor tooth center line is deviated from a stator tooth center line on one side by 40 degrees; performing phase change at a phase change angle of 30 degrees; and rotating the motor continuously. The two groups of salient pole stators being staggered away by a certain mechanical angle are based on a torque overlapping principle, and torques generated by windings on both sides are overlapped, so that the torque of an axial excitation dual-salient-pole motor is increased, and the torque pulsation is reduced.

The invention belongs to the field of mining hydraulic motors, and particularly discloses a horizontal hydraulic cylinder type motor. The horizontal hydraulic cylinder type motor aims to achieve the technical purposes that the structure is simple, operation is convenient, safety coefficients are high, service life is long, and the underground coal mine accident rate can be effectively reduced. The horizontal hydraulic cylinder type motor comprises a box, three hydraulic cylinders, a crankshaft, a box front end assembly and a control system. An installing seat board is arranged at the bottom of the box, the hydraulic cylinders are arranged in the box side by side, the ends of pistons of the hydraulic cylinders are connected with the crankshaft through piston end covers, the output end of the crankshaft and the installing seat board are arranged on the same side, the hydraulic cylinders move in a reciprocating mode to drive the crankshaft to rotate, the crankshaft drives the control system to move, the control system controls reciprocating motion of the three hydraulic cylinders to drive the crankshaft to conduct continuous rotational motion, the hydraulic cylinders drive the crankshaft to rotate, the rotating speed is low, torque is large, and the horizontal hydraulic cylinder type motor meets the requirements for use of underground coal mine equipment.

The invention discloses a balance-adjustable bilateral drive axial plunger motor which comprises a cylinder, an oil distribution disc, shells, a transmission shaft and a pressure intensity micro-adjustment device. Multiple rows of plunger holes evenly distributed around concentric circles are formed in the cylinder. The oil distribution disc is provided with multiple rows of oil suction ports and oil drainage ports. The oil drainage ports in each row of the oil distribution disc are communicated with an oil outlet through the corresponding shell. The oil suction ports in each row of the oil distribution disc are communicated with an oil inlet through the corresponding shell. The oil suction ports in the outer row or the oil outlets of the oil distribution disc are communicated with oil outlets of the pressure intensity micro-adjustment device. The stability of the bilateral drive axial plunger motor under high pressure and large loads can be well guaranteed, the design difficulty of the bilateral drive axial plunger motor can be greatly reduced, the service life of the bilateral drive axial plunger motor is prolonged, and the bilateral drive axial plunger motor is simple, feasible and good in application prospect and popularization value.

The invention discloses a three-phase doubly salient motor with non-uniform stator pole width distribution. The three-phase doubly salient motor comprises a stator iron core, a rotor iron core, an excitation element, an armature winding and a rotating shaft, and is characterized in that the rotor iron core is arranged inside the stator iron core, the rotating shaft is arranged inside the rotor iron core, the excitation element is arranged at the yoke part of the stator iron core, the armature winding is wound on the stator pole of the stator iron core, a rotor pole is arranged on the rotor iron core, the pole width of the stator pole is unevenly distributed, the pole width of the rotor pole is evenly distributed, the maximum pole width dmax of the stator pole is equal to the pole width of the rotor pole, the minimum pole width dmin is two thirds of the pole width of the rotor pole, the rotor iron core and the stator iron core are both of a salient pole structure, the number of the rotor poles is 4N, the pole-arc coefficient of the rotor is 0.5, the number of the stator poles is 6N, and N is a positive integer. According to the invention, approximate sine of the induction electromotive force of the armature winding of the doubly salient motor is realized, so that the doubly salient motor can adopt sine wave power supply, the torque ripple of the doubly salient motor is reduced, and the iron core loss of the motor is reduced.

The invention discloses a built-in alternative-pole permanent-magnet motor based on a rotor complementary structure. In the motor, a permanent magnet pole S (7), a permanent magnet pole N (8) and an iron core pole (9) are respectively disposed in a first rotor (2), a second rotor (3) and a third rotor (4) in a heteropolar alternative-pole mode. The three-rotor structure is nested in a stator (1),and is coaxial with the stator (1). The stator (1) comprises armature teeth (5) and fault-tolerant teeth (6), wherein the armature teeth (5) and fault-tolerant teeth (6) are alternately arranged alongthe periphery of the stator (1). The armature teeth (5) is provided with an armature winding (10), and the armature winding (10) is wound in a mode of single-layer fractional-slot centralized winding. Compared with a multi-stator structure and a distributed winding, the alternative-pole rotor complementary structure is simple and reliable, is low in cost, has no magnetic circuit coupling, is small in copper loss, and is high in efficiency. Because the stator (1) is just provided with one single-layer fractional-slot centralized winding, a motor end part is small in loss, and the torque and power density are high.