69 results about "Sinusoidal current" patented technology

The invention discloses a battery peak power prediction method and system based on multi-modal data coupling mapping, and relates to the technical field of lithium ion power battery management. The method comprises the following steps: acquiring electrochemical parameters and thermophysical parameters of a battery to be detected, and constructing a single-particle thermal coupling model; injecting a plurality of sinusoidal current disturbances with different frequencies into the battery to be detected, synchronously sampling voltage and current, and extracting an impedance real part under each frequency; mapping an impedance real part and the decomposed total DC internal resistance according to a mapping relation among impedance, temperature and aging; performing closed-loop correction by using an extended Kalman filter to obtain a dynamic total internal resistance; and calculating the maximum allowable current according to the dynamic total internal resistance based on the current open-circuit voltage and cut-off voltage constraint, and further outputting the instantaneous peak power of the load end. According to the method, accurate online estimation is carried out on the instantaneous peak power of the battery under the conditions of the full life cycle and the full weather of the vehicle.

The invention discloses an open-circuit fault diagnosis method for a motor driving system, and the method comprises the steps: constructing a fault index of each phase through mathematical transformation, filtering and sliding average processing according to a zero-state conservation equation of a multi-phase motor; according to the characteristic value expression of the fault index under the fault condition, a threshold value judgment method is designed; meanwhile, performing absolute value, average value and filtering processing on the fault index of each phase to construct a fault diagnosis index of an upper switch and a lower switch of each phase; and finally, integrating the upper and lower switch fault diagnosis indexes to obtain each phase fault flag variable, and combining the fault diagnosis table to obtain a fault diagnosis result of the multi-phase motor driver. In a fundamental wave period, the open-circuit fault position of the motor winding and the power device can be rapidly and accurately detected, the universality is high, the diagnosis precision is high, the algorithm is simple, the real-time performance is high, particularly, the robustness to non-sinusoidal current is high, and an effective basis is provided for further fault-tolerant control and system fault processing.

The invention provides a non-power-cut test method for mutual inductance parameters of a power transmission line under excitation of different-frequency signals and a related device, and solves the problems of difficulty in accompanying stop and high safety risk of adjacent lines. The method comprises the following steps: selecting one circuit in the same corridor for power failure, connecting the head end with an induced electricity suppression device, and performing three-phase short-circuit grounding at the tail end; injecting a different-frequency sinusoidal current of 45-55Hz into the power failure line; the synchronous measurement device collects head and tail voltage and current of a running line based on a satellite synchronous clock; extracting pilot frequency signals through two-stage notch filtering and Fourier transform; and different-frequency zero-sequence self-impedance and mutual impedance are calculated and converted into power-frequency impedance. According to the invention, accurate test without power failure can be realized, and safety and power supply reliability are guaranteed.

The invention provides a motor detection method and device, electronic equipment and a storage medium, and the method comprises the steps: controlling a motor to operate under a first identification parameter, and calculating a phase resistance value of the motor under the first identification parameter; controlling the motor to operate under a second identification parameter, and collecting a sinusoidal current response signal of the motor under the second identification parameter; calculating a d-axis inductance value and a q-axis inductance value based on the sinusoidal voltage excitation signal, the sinusoidal current response signal and the phase resistance value; the motor is forcibly dragged in a current-frequency ratio control mode, so that the rotating speed of the motor is increased to the target rotating speed; and calculating the flux linkage coefficient by combining the steady-state voltage and the current value of the motor at the target rotating speed with the d-axis inductance and the q-axis inductance. According to the method, the detection precision of the motor parameters can be improved.

The invention discloses a domestic high-power IGBT rectification system and method, and relates to the technical field of IGBT rectification, and the method comprises the steps: constructing an active front-end rectification main circuit; a direct current side hybrid harmonic modulation auxiliary circuit is integrated; performing multiple delay signal elimination operation on the sampled signal, filtering out a harmonic interference signal, and locking the frequency and phase of the fundamental voltage of the power grid through a phase-locked loop; establishing a control structure of a voltage outer loop and a current inner loop, generating an instruction amplitude of a grid-side active current and an ideal sinusoidal current reference waveform, and controlling an IGBT in an active front-end rectification main circuit in real time; real-time fast Fourier transform analysis is carried out on the actual input current of the grid side, and residual harmonic components are identified; and feedback management of regenerated energy is realized. The invention provides a fused high-adaptability active front-end IGBT (Insulated Gate Bipolar Translator) rectification method and system which can stably operate under the condition of power grid voltage distortion and realize deep harmonic suppression and efficient energy bidirectional flow.

The invention relates to the technical field of circuit board detection, in particular to a printed circuit board drilling quality detection method and device, and the method comprises the steps: injecting sinusoidal current signals with preset frequencies into a plurality of test points of a to-be-detected drilling region of a printed circuit board, extracting impedance values under each frequency component, and calculating the drilling quality of the printed circuit board; constructing an equivalent impedance spectrum containing a real part and an imaginary part according to the impedance value; according to the interlayer structure and the equivalent impedance spectrum of the printed circuit board, calculating equivalent resistance and equivalent capacitance of the drilling area to be measured to form a characteristic parameter set; comparing the data of each grid point in the characteristic parameter set with a preset threshold value, and integrating the grid points exceeding the preset threshold value to generate a defect state mark; and performing electrical topology constraint on the defect state mark to generate a defect positioning result. According to the invention, hidden defects in the drill hole and interlayer structures can be deeply detected, the electrical performance of the drill hole can be comprehensively evaluated, and accurate defect positioning and state marking can be provided.

The invention discloses a servo motor system high-precision control method and device based on disturbance perception, and belongs to the technical field of motor control, and the method specifically comprises the steps: building a high-precision PMSM equivalent magnetic circuit model containing eddy current response based on a vector magnetic circuit theory; the method comprises the following steps: taking three-phase symmetric sinusoidal current as stator winding excitation, generating a relation model of a stator current amplitude and dq-axis current, and extracting a nonlinear characteristic of alternating-direct-axis dynamic inductance along with current change; constructing a dynamic leakage item nonlinear extended state observer DL-NIESO based on a filtering mechanism, and providing high-precision disturbance and dynamic compensation for a sliding mode controller; and establishing a self-adaptive reaching law and realizing self-adaptive control of speed error compensation and buffeting suppression according to disturbance and dynamic compensation results of the sliding mode controller. The control method provided by the invention has good response performance, robustness and smoothness, and is suitable for a high-performance servo control system.

The invention relates to the technical field of new energy automobiles, and discloses a full-life-cycle health monitoring method and system for a battery of a battery swap station, and the method comprises the steps: applying a small-amplitude sinusoidal current to a preset charge window, collecting an infrared temperature sequence, calculating the average temperature of a region, extracting the amplitudes and phases of first and second harmonic waves, and building phase equal penetration mapping in a historical stage; forming a thermalization state index and determining a biharmonic phase crossing frequency; and constructing a life function by combining the battery operation quantity. In the monitoring stage, the cross frequency predicted value of the target battery is obtained, the service life is calculated, real-time visual monitoring is achieved through cloud collaboration, and the prediction accuracy and the battery replacement safety are improved.

The application discloses an online permanent magnet flux identification method of a permanent magnet synchronous motor considering cross coupling effect and belongs to the permanent magnet flux identification technology of the permanent magnet synchronous motor. The application aims at solving the problem that the existing permanent magnet synchronous motor flux identification method does not consider the cross coupling influence of the motor, thereby causing the error of the flux observation result to be large. The application comprises the following steps: under the online stable working condition of the motor, injecting a sinusoidal current signal into the dq axis of the motor to realize three-phase direct current signal injection; calculating the motor stator resistance; injecting two groups of direct current bias voltage into the d-axis of the motor through the current loop, establishing three motor voltage equations, and then obtaining two motor voltage difference equations which eliminate the flux terms; solving to obtain the motor d-axis self-inductance L d and the motor dq-axis mutual inductance L dq ; establishing the dq-axis voltage equation considering the cross coupling, calculating the motor permanent magnet flux based on the motor stator resistance, the motor d-axis self-inductance L d and the motor dq-axis mutual inductance L dq . The application is used for the online identification of the permanent magnet flux of the permanent magnet synchronous motor.

The invention relates to a semiconductor lamp control method and an intelligent electric appliance, which are applied to the field of intelligent electric appliances, and the semiconductor lamp control method comprises the following steps: driving a semiconductor lamp to illuminate through a high-frequency sine wave current signal; the high-frequency sine wave current signal is obtained by modulating an original current signal for driving the semiconductor lamp to illuminate; collecting a current output signal output by the photoelectric sensor when the semiconductor lamp illuminates; determining the attenuation degree of the semiconductor lamp through a lock-in amplifier based on the phase difference between the high-frequency modulation current signal and the current output signal; and controlling the semiconductor lamp based on the attenuation degree. According to the invention, the problem of illumination response delay caused by aging of the semiconductor lamp is solved.

The invention discloses a pulsating voltage-based current transformer secondary circuit disconnection fault detection method, and belongs to the technical field of power distribution network fault detection. According to the invention, the correlation between the real-time voltage signal induced by the voltage transformer and the reference voltage is considered on the basis of the current transformer secondary circuit disconnection difference current criterion; the method has the core effects that the current transformer secondary circuit disconnection fault and the high-resistance grounding fault of the power transmission current are distinguished according to the pulsation rhythm with the specific length in the correlation coefficient between the real-time voltage signal and the reference voltage information, so that the small-amplitude sinusoidal current distinguishing capability of a power transformation secondary system device is improved; and the detection accuracy of the secondary circuit disconnection fault of the current transformer of the power transmission line is greatly improved.

The application relates to a method and device for calculating frequency domain amplitude and phase angle in a memristor array, wherein the method comprises the following steps: obtaining a time domain input signal corresponding to a target memristor array, and calculating a cosine mixing signal and a sine mixing signal based on the time domain input signal, a preset cosine signal and a sine signal; applying the cosine mixing signal and the sine mixing signal to corresponding row lines of the target memristor array respectively, so as to calculate cosine current data and sine current data based on a discrete Fourier transform matrix of the corresponding row lines; obtaining current information of each frequency point in the target memristor array based on the cosine current data and the sine current data, and reading phase information and amplitude information corresponding to each frequency point in the current information through a preset phase discriminator and a peak value detector respectively. Thus, the problems that the prior art cannot directly calculate the amplitude and the phase without increasing additional hardware overhead and operation delay, and the efficiency of frequency domain amplitude and phase angle calculation is greatly affected are solved.

A current mode sinusoidal oscillator includes a current amplifier with distinct current input and four output terminals. The amplifier includes a current input terminal X, a first and a second negative current feedback terminals Ifo1 and Ifo2, along with a positive current output terminal Iop and a negative current output terminal Ion. The oscillator is characterized by a first feedback path that transmits a portion of a current at the first negative current feedback terminal Ifo1 to the current input terminal X of the oscillator. Additionally, a second feedback path, interlinking Ifo2 and X, comprises a three-stage phase lag network designed to confer a phase shift of negative 180 degrees to the current signal at a frequency of oscillation determined by capacitor and resistor values of the three-stage phase lag network. A load is connected between Iop and Ion, which receives the sinusoidal current at the frequency of oscillation.

This invention discloses a flexible low-frequency-flexible DC hybrid power transmission system and its control method. The hybrid power transmission system of this invention includes a receiving-end converter station, a low-frequency AC renewable energy power station, and a high-frequency DC renewable energy power station. The power conversion unit of the receiving-end converter station adopts a modular design. Each power module is combined in series / parallel to form the power frequency AC, low-frequency AC, and high-voltage DC ports of the converter station. Each port is connected to the power frequency main grid, the low-frequency AC port, and the DC renewable energy power station through transmission lines, respectively. The receiving-end converter station achieves voltage stability of the low-frequency AC port and the high-voltage DC port, sinusoidal current of the power frequency AC port, and DC bus voltage stability of each power module through multi-level control at the system level, bridge arm level, and module level. This invention achieves coordinated operation of flexible low-frequency and flexible DC power transmission modes, is suitable for efficient transmission from renewable energy power stations at different distances, and realizes integrated operation of different types of converter stations.

A method for controlling an electric machine, the electric machine comprising a rotor and a stator, the stator comprising a plurality of coils isolated from each other. The method comprises the following steps: applying a dynamic adjustable sinusoidal current to each motor coil; obtaining an electrical parameter for each motor coil, the electrical parameter being an average voltage over the coil or an instantaneous voltage over the coil; and utilizing a feedback-based vector control algorithm. The algorithm receives the electrical parameter and the applied sinusoidal current for each motor coil to calculate a target current vector, the target current vector determined based on the electrical parameter and the applied sinusoidal current for each motor coil. The method further involves dynamically adjusting, for each motor coil, the sinusoidal current applied to that motor coil based on the target current vector.

This invention discloses a double-layer mutually inducted coupled planar eddy current detection sensor. First, an external excitation source provides AC power input to the detection coil layer, causing the LC resonator, composed of the detection coil and a parallel resonant capacitor, to resonate, generating a sinusoidal current and forming a primary magnetic field. When the test piece is in the primary magnetic field, eddy currents are generated on its surface, creating a mutual inductance effect with the sensing coil. Changes in lift-off or disturbances in the flow direction of eddy currents at defects lead to changes in the mutual inductance coefficient, causing a change in the equivalent inductance of the sensing coil and a change in the resonant frequency. Finally, the resonant frequency is detected and extracted to obtain the detection signal. Similarly, a set of detection signals is also extracted from the reference coil. By comparing the changes in the signals detected by the reference coil and the detection coil, lift-off and defect signals are separated to obtain defect information.

The application discloses a kind of high-power IGBT rectifying system and method, it is related to the technical field of IGBT rectification, including active front-end rectification main circuit is constructed;Integrated dc side hybrid harmonic modulation auxiliary circuit;Multiple delay signal elimination operation is carried out to the signal obtained by sampling, filter harmonic interference signal, the frequency and phase of grid fundamental voltage are locked by phase-locked loop;Establish the control structure of voltage outer loop and current inner loop, generate the instruction amplitude of net side active current and ideal sine current reference waveform, and real-time control IGBT in active front-end rectification main circuit;Actual input current of net side is analyzed in real time by fast fourier transform, and residual harmonic component is identified;Realize the feedback management of regenerative energy.The application proposes a kind of active front-end IGBT rectification method and system with high adaptability of fusion type, which can operate stably under grid voltage distortion conditions, and realize deep harmonic suppression and high efficient energy bidirectional flow.

A muscle and bone dredging instrument disclosed by the present invention comprises a host and a pole piece, the host is provided with a display screen and a host power line, the host is provided with an adjusting key, a display lamp, a plurality of keys and a wire plugging hole, the pole piece is provided with an electrode socket, one end of the electrode socket is provided with a pole needle, and the other end of the electrode socket is provided with a wire. The invention relates to the technical field of physiotherapy equipment, and the core principle is that positioning electric energy is output through a body-controlled high-energy biological electro-therapeutic apparatus and is conducted to the body of a patient by a professionally trained electro-therapist through self-adjustment of current intensity, and sine wave current matched with human body cell bioelectricity waveform is utilized to excite essence and qi to dredge the channels and collaterals, so that the body-controlled high-energy biological electro-therapeutic apparatus can be used for treating body diseases. Therefore, the treatment effect that pain is not caused by general communication is achieved.

The invention belongs to the technical field of motors, and provides a method for calculating variable-frequency power supply loss of a permanent magnet synchronous motor, which comprises the following steps of: S1, establishing a finite element simulation model of the motor by utilizing simulation software, and taking sinusoidal current as excitation; s2, extracting a three-phase flux linkage in an electric period, and calculating quadrature-axis and direct-axis incremental inductances; s3, calculating the loss of the motor according to a simulation result, and calculating a loss coefficient in combination with a flux linkage; s4, calculating harmonic flux linkage under PWM harmonic voltage power supply according to a simulation result; and S5, calculating the variable-frequency power supply loss of the motor by combining the harmonic flux linkage, the loss coefficient and the frequency. The invention discloses a built-in permanent magnet synchronous motor variable-frequency power supply loss rapid calculation method based on quadrature-axis and direct-axis equivalent circuits, and aims to calculate the loss of a built-in permanent magnet synchronous motor in a variable-frequency power supply mode in a short time and ensure the accuracy of a calculation result.

The invention discloses a high-frequency constant current source generation circuit and power supply equipment, and belongs to the technical field of constant current sources. A high-frequency sinusoidal current output circuit; a DC bias current output circuit; the output end of the high-frequency sinusoidal current output circuit and the output end of the direct-current bias current output circuit are both connected with one end of the current detection resistor, and the other end of the current detection resistor is used for being connected with a load; the input end of the feedback loop is connected with the current detection resistor, and the output end of the feedback loop is connected with the controller; the feedback loop is used for extracting differential voltage at the two ends of the current detection resistor and converting the differential voltage into a direct current value; and the controller is used for adjusting the output amplitudes of the high-frequency sinusoidal current output circuit and the direct-current bias current output circuit according to the direct-current value. By arranging the feedback loop for extracting the differential voltage at the two ends of the current detection resistor and converting the differential voltage into the direct current value, the problem of amplitude control lag existing in the high-frequency constant current source is solved.

A vernier reluctance motor, comprising a stator and a rotor, wherein a tooth portion of the stator and a tooth portion of the rotor are both of a double salient pole structure; the stator is sleeved on the periphery of the rotor, and an air gap is formed between the stator and the rotor; the stator comprises a plurality of stator teeth and a plurality of stator windings; a two-layer stator winding is wound in a stator slot between every two adjacent stator teeth; each stator winding uses three-phase sinusoidal current with direct-current bias.

The invention discloses a pulsating current-based current transformer secondary circuit disconnection fault detection method, and belongs to the technical field of power distribution network fault detection. According to the invention, the correlation between the real-time current induced by the current transformer and the reference current is considered on the basis of the differential current criterion of the disconnection of the secondary circuit of the current transformer in the prior art; the method has the core effects that the current transformer secondary circuit disconnection fault and the high-resistance grounding fault of the power transmission current are distinguished according to the pulsation rhythm with the specific length in the correlation coefficient between the real-time current and the reference current, so that the small-amplitude sinusoidal current distinguishing capability of a power transformation secondary system device is improved; and the detection accuracy of the secondary circuit disconnection fault of the current transformer of the power transmission line is greatly improved.

The utility model relates to the technical field of motors, in particular to a permanent magnet synchronous motor for an air compressor. The motor comprises a stator assembly and a rotor assembly, the rotor assembly is arranged in the stator assembly, the stator assembly comprises a stator iron core, twelve uniformly distributed stator grooves are arranged on the inner circumferential surface of the stator iron core at intervals along the circumferential direction, the rotor assembly comprises a rotor iron core, and ten groups of permanent magnets are uniformly arranged along the circumferential direction of the rotor iron core. The outer diameter of the stator core is 70-130 mm, and the ratio of the inner diameter of the stator core to the outer diameter of the stator core is 0.47-0.55. By means of the technical scheme, the motor has large inductance, is suitable for FOC sine wave current control, can restrain current fluctuation of the motor, and solves the problem that the motor of the air compressor is poor in stability.

This invention discloses a method, apparatus, device, and storage medium for early warning of battery capacity drops. The method includes: detecting particulate crack features in a target battery based on acoustic emission signals to generate a crack event rate time series; measuring the electrochemical impedance spectroscopy of the target battery based on a multi-frequency sinusoidal current excitation signal, and determining a crack sensitivity index time series based on the electrochemical impedance spectroscopy; time-series fusion of the crack event rate time series and the crack sensitivity index time series to construct a dual-feature time series matrix; and quantitative identification of the dual-feature time series matrix based on preset crack event rate thresholds and crack sensitivity index thresholds to determine whether the target battery has entered the early stage of capacity drops. This invention can accurately determine whether a target battery has entered the early stage of capacity drops, thereby achieving quantitative characterization and reliable early warning of battery capacity abrupt changes.

The invention provides a control method of a three-phase rectifier and a power conversion module, and relates to the technical field of rectifiers. The control method comprises the following steps: determining a three-phase sinusoidal current reference signal according to the input voltage of a three-phase rectifier, the voltage of a first capacitor of a direct current bus and the voltage of a second capacitor of the direct current bus; determining a common-mode signal according to the voltage of the first capacitor and the voltage of the second capacitor; according to the sinusoidal current reference signal, the carrier signal and the common-mode signal of any phase in the three-phase sinusoidal current reference signals and the input current of the corresponding phase, a gate signal of the corresponding phase is determined, and the gate signal of the corresponding phase is used for controlling the switch-on or switch-off of the switch unit of the corresponding phase. According to the invention, when the voltage of the power grid is distorted or unbalanced, the operand required for control and the control difficulty of the rectifier can be reduced.

A method for controlling a motor comprising a rotor and a stator, the stator comprising a plurality of coils which are isolated from each other. The method includes applying a dynamically adjustable sinusoidal current to every motor coil, obtaining an electrical parameter for each motor coil, which is either an average voltage over the coil or an instantaneous voltage over the coil, and utilizing a feedback-based vector control algorithm. This algorithm receives the electrical parameter and the applied sinusoidal current for each motor coil to calculate a target current vector, which is determined based on the electrical parameter and the applied sinusoidal current for each motor coil. The method further involves dynamically adjusting for each motor coil the sinusoidal current applied to that motor coil based on the target current vector.

A current mode sinusoidal oscillator includes a current amplifier with distinct current input and four output terminals. The amplifier includes a current input terminal X, a first and a second negative current feedback terminals Ifo1 and Ifo2, along with a positive current output terminal Iop and a negative current output terminal Ion. The oscillator is characterized by a first feedback path that transmits a portion of a current at the first negative current feedback terminal Ifo1 to the current input terminal X of the oscillator. Additionally, a second feedback path, interlinking Ifo2 and X, comprises a three-stage phase lag network designed to confer a phase shift of negative 180 degrees to the current signal at a frequency of oscillation determined by capacitor and resistor values of the three-stage phase lag network. A load is connected between Iop and Ion, which receives the sinusoidal current at the frequency of oscillation.

The permanent magnet synchronous motor parameter identification method based on fuzzy adaptive control has the following steps: inputting a frequency value f0, an amplitude value, and a bias value of a d-axis current signal at a set angle, performing PI setting of a current loop, and obtaining K p , K i of the current loop; giving a d-axis step current instruction, adopting a mean value and difference method to obtain an identification resistance; giving a d-axis sinusoidal current instruction, and utilizing a least square method with a forgetting factor to obtain an identification d-axis inductance; giving a q-axis sinusoidal current instruction, and obtaining an identification q-axis inductance according to a q-axis voltage, a q-axis feedback current and the identification resistance; and giving a q-axis step current instruction, and obtaining a flux according to the q-axis voltage, the q-axis feedback current, a motor rotating angular velocity and the identification resistance. The method is a closed-loop offline parameter identification method, and has the advantages of simple and reliable identification process, universality, controllable current, high safety, no motor rotation except for identification of the flux, and applicability to different occasions.

This invention relates to a rapid heating device for lithium-ion batteries that also supports EIS measurement. It includes a battery module, a DC / DC voltage regulator module, a heating module, a heating control system, and an EIS detection and control system. The DC / DC voltage regulator module integrates an isolation transformer, switching components, an independent control logic unit, and an energy storage capacitor to form an isolated boost structure, achieving voltage boost and maintaining stable high-voltage DC bus voltage. The heating module includes an H-bridge structure, a heating inductor, and a heating capacitor. It achieves two operating modes through a switching control strategy: in heating mode, it generates AC current to heat the battery module; in EIS measurement mode, it generates sinusoidal currents of different frequencies to facilitate EIS measurement. The heating control system adjusts heating parameters in stages. The EIS detection and control system obtains EIS data by detecting the voltage response of the battery module, enabling the detection of the battery's health status. This invention integrates low-temperature rapid heating with EIS measurement, providing precise temperature control and ensuring battery performance and safety.

The invention relates to a power transmission line overhead ground wire impedance measurement circuit and method and a ground wire state monitoring device. The power transmission line overhead ground wire impedance measurement circuit comprises a single-chip microcomputer, a full-bridge circuit, a measurement transformer, a voltage detection circuit and a current detection circuit. The single-chip microcomputer drives the full-bridge circuit to work and outputs a sinusoidal current signal, and after the sinusoidal current signal passes through the measuring transformer, a secondary coil of the measuring transformer outputs a sinusoidal voltage signal to the line segment to be measured; meanwhile, the primary side current of the measuring transformer is detected through the current detection circuit, and the induced voltage of the line segment to be measured is detected through the voltage detection circuit; and calculating the primary side current and the induced voltage through the single-chip microcomputer to obtain an impedance value of the line segment to be measured. Primary side current is collected through the current detection circuit, ground wire induced voltage is collected through the voltage detection circuit, the impedance value can be calculated according to the primary current and the induced voltage, and the ground wire impedance measurement precision is improved.