6results about How to "Reduce harmonic components" patented technology

This application discloses a grid-connected inverter control method based on a notch filter phase-locked loop (PLL) for weak grid conditions. The method first designs a notch filter with adjustable notch depth and bandwidth, setting its notch frequency to the grid power frequency. It then acquires the three-phase voltage at the grid connection point, subtracts the voltage after notching, and extracts the power frequency component of the three-phase voltage. The power frequency component is phase-locked in a synchronous reference frame to obtain the modulation wave phase signal. The inverter output voltage and current are acquired, and active and reactive power are calculated. A dual closed-loop control circuit with an outer power loop and an inner current loop is constructed, outputting the modulation wave voltage amplitude signal. Finally, the modulation wave phase signal and amplitude signal are combined to generate a pulse modulation wave signal. Thus, this invention can accurately lock the grid phase when the weak grid voltage contains harmonics and DC components, effectively improving the stable grid-connected operation capability of the grid-connected inverter under large disturbances.

The utility model belongs to the technical field of artificial heart-left ventricle auxiliary circulation equipment, and particularly discloses an LVAD motor stator system, which comprises an outer stator, an inner stator and a winding arranged between the outer stator and the inner stator, the inner stator is formed by stacking a plurality of silicon steel ring sheets, an axial modulation groove is arranged along the circumferential direction of the inner side of the inner stator, and the inner side of the inner stator is connected with the winding. According to the utility model, the modulation grooves are arranged in the inner stator, so that the harmonic amplitude is reduced, and the fluctuation of the torque is reduced. The utility model also discloses a motor which is filled with epoxy resin, so that the relative positions of related parts are ensured, the coaxiality and dynamic balance of the related parts are ensured, the motor is stable in high-speed operation, the vibration can be reduced, the motor has relatively good biological safety, relatively high heat conductivity coefficient and chemical stability, and the heat is quickly dissipated when the motor is in high-speed operation. The device is suitable for being placed in a human body.

The utility model belongs to the technical field of industrial automation measurement and control, and discloses an isolation type thermal resistance temperature signal conditioning system, which comprises a constant current source circuit; an amplification circuit; a VF conversion circuit; an FV conversion circuit; a low-pass filter circuit; and a linearization circuit. According to the utility model, the instrument amplifier with a high common-mode rejection ratio is adopted to suppress common-mode noise, the hardware filtering design is optimized, multi-stage low-pass filtering is adopted to eliminate power frequency harmonic waves, and a mirror image constant current source is adopted to enhance the stability; a reverse protection circuit is added in a double-TVS diode clamping mode, and a wide input voltage range power supply chip is properly selected. VF / FV conversion time sequence control is adopted, a scheme of dynamically adjusting cut-off frequency is adopted, filtering parameters are automatically switched according to a signal variable rate, and noise suppression and response speed are balanced.

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 utility model discloses a rotor assembly and a motor, and relates to the technical field of motors, the rotor assembly comprises a rotor yoke, a plurality of radial magnetic shoes and a plurality of circumferential magnetic shoes, and the rotor yoke is configured to be annular and rotates around a rotation axis; the plurality of radial magnetic shoes are connected to the inner side of the rotor yoke and configured to be magnetized in the radial direction of the rotating axis, and the plurality of radial magnetic shoes are arranged at intervals in the circumferential direction of the rotating axis; the plurality of circumferential magnetic shoes are connected to the inner side of the rotor yoke and configured to be magnetized in the circumferential direction of the rotating axis, and the plurality of circumferential magnetic shoes are located between every two adjacent radial magnetic shoes respectively; one side surface, facing the rotating axis, of each radial magnetic shoe comprises a first arc surface, and a first surface and a second surface which are connected to the two sides of the first arc surface in the circumferential direction, the distance between the first surface and the rotating axis is gradually increased in the direction away from the first arc surface, and the distance between the second surface and the rotating axis is gradually increased in the direction away from the first arc surface. The rotor assembly of the utility model can enhance the electromagnetic performance and improve the mute effect.

The application discloses a low-tooth-groove primary permanent magnet linear motor and belongs to the technical field of motors. The application aims at the problem of high tooth groove force of the primary permanent magnet linear motor. The primary permanent magnet linear motor comprises a primary and a secondary, the primary comprises a primary iron core, an armature winding and permanent magnets, the armature winding is wound on the armature tooth of the primary iron core, the armature winding is composed of concentrated windings, the tooth top of the armature tooth is processed with a plurality of unequal-width split teeth to form an odd number of split tooth grooves, the permanent magnets are embedded in the split tooth grooves, the permanent magnet in the middle split tooth groove is higher than the permanent magnets in the split tooth grooves on the two sides, and the plurality of permanent magnets form a non-uniform air gap magnetic field between the primary and the secondary. The application is suitable for high-precision direct drive motion control occasions.