33results about How to "Reduced torque ripple" patented technology

A power conversion apparatus (2) includes: an inverter unit (20) having high and low potential-side switching elements (21-26) corresponding to each phase of a winding (15) of a rotating electrical machine (10); a current detecting unit (40); a current obtaining unit (42) obtaining a current detection value with a fixed interval sampling timing; and a control unit (60) controlling the switching elements based on a PWM reference signal and a duty instruction value. The control unit (60) includes: a phase current computing device; voltage instruction value computing devices (63, 64); and a duty computing device. The phase current computing device computes a correction current based on positive and negative side corrected current detection values. The positive-side corrected current detection value is obtained when a duty is adjusted to a positive side, and the negative-side corrected current detection value is obtained when the duty is adjusted to a negative side.

The invention relates to the technical field of petroleum drilling and well cementation, in particular to a composite drill bit which comprises a PDC drill bit body and roller cones. The roller cones are installed on the PDC drill bit body. The roller cone and PDC composite drill bit is composed of the roller cones and PDC, the advantages of roller cone drill bits and PDC drill bits are combined, the aggressivity is high, the cutting efficiency is high, the mechanical drilling speed of the composite drill bit is 2-4 times higher than the roller cone drill bits when the composite drill bit operates on poor-drillability stratums (such as igneous rock and mud and sand interbeddings containing gravels), and the mechanical drilling speed and the rotation speed are in direct proportion. When a motor is adopted by the roller cone and PDC composite drill bit for drilling, the mechanical drilling speed is increased remarkably. Another advantage is reflected in the influences of the roller cones on drill bit dynamics, compared with the conventional PDC drill bits, the torque fluctuation degree can be reduced by as much as 50%, the torsional vibration degree is lowered under the low rotation speed condition, and the whirling vibration degree is lowered under the high rotation speed condition.

The invention provides a high-performance permanent magnet servo motor, which comprises a stator and a rotor, wherein the stator comprises a stator core and a coil; the coil is wound on the stator core; the rotor comprises a rotor core and a permanent magnet; the permanent magnet is arranged on the periphery of the rotor core; the high-performance permanent magnet servo motor is characterized in that the stator core is formed by laminating stator punching plates; each stator punching plate is formed by splicing at least two stator tooth punching plates; the rotor core is formed by laminating rotor punching plates; a permanent magnet groove is formed in the periphery of the rotor core; and the permanent magnet is embedded into the permanent magnet groove. According to the high-performance permanent magnet servo motor, improvement of the utilization rate of a silicon steel sheet is facilitated; the offline production rate is improved; the slot space-factor can be improved; the coils in a slot are arranged regularly and densely; and heat dissipation of the coils is facilitated.

The purpose of the invention provides a permanent-magnet type rotating electrical machine. Magnet inserting holes (7a-7c), into which a plurality of permanent magnets are to be embedded for each pole, are formed on a rotor iron-core (6) in protrusion towards the center of the rotor, and pairs of magnetic-flux controlling holes (20a, 20b) that are symmetrical with respect to the centerline between magnetic poles are formed at inter-pole sections (22) of the rotor iron-core (6), for each of the magnetic poles. When the diameter of the magnetic-flux control holes (20a, 20b) is assumed to be d, the distance between the centers is assumed to be m, the width of the inter-pole sections (22) is assumed to be b, and the pitch between the magnetic poles is assumed to be tau, the magnetic-flux control holes (20a, 20b) are formed so that the value of m/tau, which is a value resulting from standardizing the distance between the centers (m) with the pole pitch (tau), will satisfy a relationship of 0.08 (m/tau((b-2d)/tau.

The invention relates to an intermediate-speed large-torque radial plunger hydraulic motor which comprises a casing (1), a crankshaft (2), a roller (3), a bearing bush (4), a cylinder head (5), a telescopic sleeve (6), a retainer ring (7), a hanger rod (8) and a drive shaft (10).The telescopic sleeve (6) is arranged along the radial direction of the bearing bush (4), and the upper end and the lower end of the telescopic sleeve (6) are respectively abutted against an external spherical surface (501) of the cylinder head (5) and an external spherical surface (402) of the bearing bush (4).The lower end of the telescopic sleeve (6) is closely attached to the external spherical surface (402) of the bearing bush (4) by the retainer ring (7).The upper end of the telescopic sleeve (6) is closely attached to the external spherical surface (501) of the cylinder head (5) by the hanger rod (8).Two ends of the drive shaft (10) are respectively connected with the crankshaft (2) and an oil distributing mechanism (9).The roller (3) is inserted in an inner bore (401) of the bearing bush; and the crankshaft (2) comprises an eccentric section (201).Compared with the prior art, the radial plunger hydraulic motor has the advantages of highly increased revolution speed and compact structure.

Systems and methods directed to improved battery management, motor control, energy storage and battery charging. The systems and methods enable vehicle electrification and provides a paradigm changingplatform that enables integration of battery management, charging and motor controls with means to manage regenerative braking, traction and handling. In embodiments, systems and methods are directedto a unified modular battery pack system having a cascaded architecture comprising an integrated combination of a networked low voltage converter/controller with peer-to-peer communication capability, embedded ultra-capacitor or other secondary energy storage element, battery management system and serially connected set of individual cells as the fundamental building block.

The invention provides a switched reluctance motor including a U-shaped rotor magnetic pole structure. The switched reluctance motor comprises a stator and a rotor, wherein the stator and the rotor are coaxially arranged. The stator comprises a number of stator magnetic poles uniformly distributed in the circumferential direction. Each stator magnetic pole comprises a stator magnetic pole root anda number of stator magnetic pole teeth extending radially from the stator magnetic pole root toward the rotor. Each stator magnetic pole is wound with a coil. The rotor comprises a number of rotor magnetic poles uniformly distributed in the circumferential direction. Each rotor magnetic pole comprises a rotor magnetic pole root and a number of rotor magnetic pole teeth extending in the circumferential direction from the same side of the rotor magnetic pole root, wherein the rotor magnetic pole teeth and the rotor magnetic pole root share the same curvature. A number of stator magnetic pole teeth and a number of rotor magnetic pole teeth are axially aligned with each other. According to the switched reluctance motor provided by the invention, radial vibration and torque ripple of the motor can be significantly reduced; noise generated by radial vibration can be reduced; and the motor efficiency is improved.

The invention relates to the technical field of permanent magnet synchronous motors, in particular to a torque pulsation compensation method based on current harmonic analysis and open-loop torque control, which comprises the following steps of: calculating a-phase current, b-phase current and c-phase current, calculating phase current, substituting the phase current into a current fundamental wave and torque formula to obtain torque, converting a three-phase static coordinate system into a rotating coordinate system, and calculating the torque pulsation. 24-order torque pulsation is obtained, and the value of the 24-order torque pulsation is shown in the specification; 24-order torque pulsation is substituted into an open-loop torque control compensation formula to obtain torque harmonic waves, a torque harmonic wave formula is obtained, the torque harmonic wave formula is adopted to replace the torque harmonic waves of open-loop torque control in an original model, and a 24-order noise compensation model is established. Compared with the prior art, the torque pulsation compensation method based on current harmonic analysis and open-loop torque control is designed, compensation of torque pulsation is achieved by establishing a relation formula of current harmonics and torque harmonics and establishing a model, and therefore the torque pulsation and noise of the electric power steering system are reduced.

The invention relates to a permanent magnet synchronous motor sliding mode control method based on a combined reaching law and a storage medium, and the sliding mode control method comprises the steps: 1, obtaining the actual rotor angular speed and rotor angle data of a permanent magnet synchronous motor; 2, establishing a mathematical model of the permanent magnet synchronous motor under a three-phase static coordinate system, and obtaining current component data under a two-phase static coordinate system; 3, obtaining voltage component data through a speed loop and a current loop; 4, obtaining inverter switching signal data through the voltage component data; 5, enabling the switching signal data to pass through a three-phase inverter, and then outputting three-phase stator voltage data; and 6, controlling the rotating speed and the torque of the permanent magnet synchronous motor by using the three-phase stator voltage data to realize the speed regulation of the motor. Compared with the prior art, the method has the advantages of being good in control effect, high in response speed, good in robustness and the like.

A single-phase permanent magnet synchronous motor and dust collector. The single-phase permanent magnet synchronous motor includes a plurality of stator teeth, the plurality of stator teeth include at least: a first-type and second-type stator tooth; the first-type and second-type stator teeth enclose an annular working cavity for accommodating a rotor part, where the size of a central angle corresponding to a first contour line of an end face of the first-type stator tooth facing the rotor part is different from the size of a central angle corresponding to a second contour line of an end face of the second-type stator tooth facing the rotor part The motor has a significantly reduced cogging torque, a greatly reduced torque ripple, and an obviously increased motor output torque. The single-phase permanent magnet synchronous motor is small in size, light in weight, simple in structure, convenient for large-scale manufacture and low in manufacturing cost.