17results about How to "Harmonic reduction" patented technology

The invention provides a dead zone compensation method, device and equipment of an energy storage converter, a medium and a product, and relates to the technical field of energy storage systems. According to the method, the interval of each phase of current is determined according to the three-phase output current acquired by the current sensor, and the basic dead zone compensation amount is dynamically calculated by combining the preset linear function, so that the problem of overcompensation or undercompensation caused by the fact that the existing fixed compensation amount method does not consider the compensation demand difference of different current magnitudes is avoided; the compensation direction is determined by obtaining the instantaneous value of each phase of modulation wave so as to obtain the target dead zone compensation amount, and accurate matching of the compensation direction and the expected output voltage direction is ensured; and the target dead-zone compensation amount and the original modulation wave are superposed to generate a corrected modulation wave, and then a pulse width modulation signal driven by a switching tube is generated, so that the pulse width modulation waveform difference caused by dead-zone time can be effectively counteracted, the output current harmonic wave of the energy storage converter is reduced, and the energy storage efficiency is improved. And stable and reliable operation of the energy storage converter and the whole energy storage system is ensured.

The application discloses a random rotation DEM structure for reducing switch activity, comprising a digital-to-analog converter, a digital input of the digital-to-analog converter is divided into an input code and a random rotation number, the random rotation number is input into a switch activity reduction structure through a barrel shifter output result delayed by a D flip-flop for one period, a feedback output of the switch activity reduction structure is fed back to the barrel shifter as an input, and an output of the barrel shifter after rotation controls corresponding switches and is connected to a corresponding cell array. The application uses input data to replace a pseudo-random number generator, and uses relatively simple logic to realize a switch activity reduction function, so that the complexity is reduced.

The present application relates to a kind of functionization outer diameter unequal thickness magnetic ring and its magnetizing method, belong to permanent magnet motor technical field, the inner diameter of unequal thickness magnetic ring is circular, and the outer diameter is change curve, wherein, the change curve of outer diameter is constant in main magnetic pole portion thickness, and the thickness is reduced in the transition position between adjacent main magnetic pole portion;The unequal thickness magnetic ring adopts bonded neodymium iron boron material.The present application is composed of a functionization outer diameter bonded neodymium iron boron magnetic ring and its matching multipole magnetizing fixture, wherein the outer diameter of magnetic ring adopts two kinds of functionization size, by reducing the thickness of magnetic pole transition area, the harmonic component of surface magnetism of magnetic ring is controlled, and the amplitude of cogging torque is reduced.The multipole magnetizing core of matching magnetizing fixture can magnetize magnetic ring into surface alternately distributed multiple magnetic poles.

The application belongs to the technical field of electronic power, and particularly relates to a multi-target hybrid modulation method, system and device of a T-type three-level inverter. The method firstly judges whether the inverter is operated at an extremely low modulation degree; if yes, the theoretical midpoint currents of DPWM1 and DPWM3 modes are calculated in parallel, and the extended midpoint currents corresponding to four hybrid modulation modes generated after the introduction of VSVPWM sequences in the two modes are calculated; then, according to the numerical relationship between the real-time calculated midpoint compensation current and the midpoint currents, the optimal hybrid modulation mode is dynamically selected or the basic DPWM mode is returned to; finally, three-phase double modulation waves are generated, and PWM signals for driving all power switches are output after carrier comparison. The application realizes multi-target optimization of the midpoint potential, switching loss and output waveform under extreme working conditions, and significantly improves the system stability and performance.

The application provides a compact high-voltage generator with excellent heat dissipation performance, and belongs to the technical field of high-voltage generators, and solves the technical problems of complex structure and poor heat dissipation performance of the existing generator. The application comprises a water-cooled generator shell, the rear end of the water-cooled generator shell is provided with a rear end cover, the front end of the water-cooled generator shell is provided with a linkage heat dissipation end assembly, the rear end cover and the linkage heat dissipation end assembly are provided with a stator assembly, a rotor shaft is rotatably arranged in the stator assembly, the two ends of the rotor shaft are rotatably arranged between the rear end cover and the linkage heat dissipation end assembly, a plurality of rotor assemblies are arranged on the rotor shaft, the plurality of rotor assemblies are arranged in the stator assembly, an electric control box is arranged above the water-cooled generator shell, and a mounting base is arranged below the water-cooled generator shell. The application has a water-cooled main heat dissipation system and an air-cooled auxiliary heat dissipation system, has good heat dissipation effect, is deeply integrated, has a modular structure, significantly reduces the volume, and is stable in operation and reduces the maintenance cost.

This application provides a radio frequency (RF) device and its inductor. The RF device includes a power amplifier circuit, a signal coupling circuit, an extraction circuit, and a harmonic filter circuit. The power amplifier circuit amplifies a differential signal to output a signal to be filtered. The signal coupling circuit includes a primary inductor and a secondary inductor. The signal coupling circuit receives the signal to be filtered through the primary inductor and outputs a single-ended signal from the secondary inductor. The extraction circuit has a center tap. The extraction circuit couples with the primary inductor and outputs a common-mode signal from the center tap. The harmonic filter circuit performs harmonic filtering on the single-ended signal based on the common-mode signal, so that the secondary inductor of the signal coupling circuit outputs a filtered signal.

The application belongs to the technical field of communication, and particularly relates to a radio frequency front-end module and a radio frequency chip. The radio frequency front-end module comprises a power amplification circuit, a transceiving switch circuit, a filter circuit, an antenna switch circuit, a matching adjustment circuit, a low-noise amplification circuit and an antenna end; the antenna switch circuit comprises a switch unit, a coupling unit, a first trap unit, a second trap unit, a third trap unit, a first inductor and a second inductor; a first end of the switch unit is used as a first end of the antenna switch circuit, and a second end of the switch unit is connected with a first end of the coupling unit; a second end of the coupling unit is connected with a first end of the first trap unit, and the coupling unit is used for extracting part of power in a radio frequency signal for detection and calibration. Compared with the prior art, the radio frequency front-end module of the application precisely suppresses and blocks low-frequency multiple harmonics, cooperates with a high-low frequency dual-module filtering scheme, and greatly improves the harmonic suppression capability.

The invention discloses a permanent magnet synchronous motor and a single-resistor current sampling method. The permanent magnet synchronous motor controls a three-phase inverter based on an SVPWM strategy, and the method comprises the following steps: in a current control period, acquiring flow directions of A, B and C three-phase current; according to the flow direction of the ABC three-phase current and a sector where a target voltage vector is located, whether the minimum time window of single-resistor sampling in the current control period can cancel dead time or not is determined; and according to the determined minimum time window, determining whether to adjust the two-phase sampling in the current control period. According to the scheme provided by the invention, sampling can be carried out by directly utilizing the dead time under some conditions, so that the number of times of PWM waveform adjustment is reduced, the stability of the system is improved, and the collected current is closer to the same moment.

This invention discloses a scalable power very low frequency (VLF) transmitter device and its control method. It consists of multiple individual cabinets, with multiple units sharing a single main control system, facilitating expansion and allowing for power level adjustments, improved waveform quality, and reduced output waveform harmonics. The input terminals of multiple individual power cabinets can be connected in parallel to DC or AC power supplies, and the output terminals are connected in series to the load. Each cabinet includes a switching module, a voltage conversion module, an adjustable voltage module, multiple switching signal modules, multiple multi-tap high-frequency transformers, and a corresponding number of bypass switches. The unique design of the switching signal modules facilitates online expansion and replacement. The high-frequency transformers are multi-tap high-frequency transformers; adjusting the tap positions allows for graded adjustable output voltage after multiple units are connected in parallel. The main control system includes a command control unit, a stepped waveform generation and expansion unit, a storage unit, and a communication unit. The main control system can multiply the comparison value and pulse quantity based on the individual unit comparison value using interpolation methods to provide pulse signals to the switching signal modules.

A method and a sensor system for calibrating a magnetic sensor system are provided. The position of the magnetic structure varies within a calibration range when measuring at least four components of the magnetic field generated by the magnetic structure having a main orbit and a nonius orbit. The uncalibrated position of the structure is determined and compared with a corresponding reference position. A periodic function is obtained by calculating two coefficients of a function such that the function applied to the uncalibrated position minimizes the error caused by the comparison with the reference position.

The application provides a motor rotor, a self-starting synchronous reluctance motor, a compressor and a motor rotor. The motor rotor has a slit slot, a second filling slot and a first filling slot on a first rotor lamination. An outer magnetic barrier layer includes the first filling slot, and an inner magnetic barrier layer includes the slit slot and the second filling slot at both ends of the slit slot. Between the second filling slot and the slit slot in the same layer of the inner magnetic barrier layer, there is a separation rib. A side of the separation rib close to an outer circle of the rotor has a center point in an axial plane. The distance between two center points corresponding to two separation ribs in any two adjacent layers of magnetic barrier layers along a d-axis direction is L. The maximum distance between the filling slots in the two adjacent layers of magnetic barrier layers along a q-axis direction is W, and 0<=L<2W. According to the application, the saturation degree of the magnetic conduction channel between the filling slots can be reduced, the motor harmonics can be reduced, the torque ripple can be reduced, the harmonic loss can be reduced, the motor efficiency and the operation stability can be improved.

A method of operating a battery storage system having at least one multilevel converter having a plurality of battery modules, the method comprising the steps of: selecting at least one battery module from the plurality of battery modules, during a specified time interval between (1) seconds and (30) days or (5) minutes and (20) days, the selected battery module is set to be in a bypass state while maintaining the multilevel converter operation, and the selected battery module is released from the bypass state.

The application discloses a disc type motor and belongs to the technical field of axial flux motors, comprising a stator and a rotor arranged on the axial two sides of the stator; the axial permanent magnet and the circumferential permanent magnet are alternately arranged in the rotor in the circumferential direction to form the magnetization distribution of Halbach arrangement, so that the air gap magnetic field is enhanced, the inter-pole magnetic flux leakage is reduced, and the utilization rate of the permanent magnet is improved; the tooth top surfaces of the two stator teeth of the stator core are respectively arranged as arc surfaces with the same or different curvature radii, the air gap magnetic flux density distribution on the two sides is close to consistent after the arc surfaces are combined with the corresponding rotor pole surfaces, the axial magnetic pull difference is inhibited, the high power density of the motor is ensured, the double air gap magnetic flux density balance is realized, the dynamic balance performance under high-speed operation is improved, the noise and vibration are reduced, and the axial force balance and the service life of the system in the steady state operation are effectively improved.

A fault-tolerant vector control strategy for H-bridge driven motors is applicable to any motor where each phase winding uses H-bridge drive and the phase difference between the remaining two phases after a fault is 120°. Fault-tolerant control can be achieved by changing the current phase and amplitude of the remaining two normal phases. First, U... αn‑βn The establishment of the coordinate system, if U at this time αn‑βn with U α‑β If they do not coincide, perform a coordinate transformation; then continue using U. βn The system performs sector identification, selects three non-zero vectors acting on that sector, calculates the vector action time, and generates a PWM for motor fault-tolerant control. Furthermore, compared to traditional vector control, the number of sector identifications is reduced to two, and the PWM waveform is differentially complementary, resulting in stronger anti-interference capabilities. This invention not only ensures the system's ability to operate with faults, enabling it to resume normal operation after fault-tolerant control and improving system reliability, but also significantly reduces torque ripple after a fault. The torque ripple after fault tolerance is reduced by at least 40% compared to the fault state, and the calculation is fast and the anti-interference capabilities are strong.

This invention provides a filtering method, apparatus, frequency converter, and storage medium. The filtering method includes: obtaining a filtering capacitor based on the cable length between the frequency converter and the motor; obtaining a filtering inductor based on the motor's rated parameters; and filtering the voltage signal to be output to the motor using the filtering inductor, the filtering capacitor, and a pulse width modulation waveform determined based on both, to obtain a filtered voltage signal. This invention improves the accuracy of filtering parameter calculation, reduces computational complexity, lowers the waveform distortion rate and phase voltage amplitude of the input voltage signal at the motor end, and reduces harmonics in the voltage signal.

The application discloses a kind of permanent magnet synchronous motor double vector model predicted current control methods considering dead zone, it is related to motor drive control technical field, comprising the following steps: S1, establish PMSM discrete prediction model and sampling: derivation current prediction equation;S2, based on the classification strategy of cost function and torque current: voltage vector is divided into overshoot vector group and under shock vector group;S3, double vector screening strategy based on classification strategy: screening out optimal double vector candidate combination;S4, dead zone determination and beatless time synthesis: output final switch control pulse.The application adopts the above-mentioned permanent magnet synchronous motor double vector model predicted current control method considering dead zone, reduces the current distortion caused by dead zone effect, solves the local optimal problem in traditional strategy, and greatly reduces the calculation burden, provides a kind of efficient control scheme with high dynamic response, global steady-state accuracy and low harmonic characteristic for ship PMSM propulsion system.