189 results about "Overmodulation" patented technology

The invention discloses a micro-grid power control method, system and device based on fuzzy modulation and a storage medium, and relates to the technical field of intelligent grid integration of a photovoltaic system and a micro-grid, and the method comprises the steps: firstly obtaining the real-time power data of a photovoltaic system, carrying out the control processing through fuzzy logic, and calculating a reference instruction; according to the reference instruction, hysteresis time is dynamically adjusted through modulation hysteresis control, and an inverter switching signal is generated; converting direct current into alternating current based on the switching signal and a power switching device, injecting the alternating current into the micro-grid, calculating active and reactive power reference values, ensuring that the system operates according to a unit power factor, and giving active power to the reference value; according to the method, the power control precision and adaptability of the micro-grid are improved, excessive switching of the inverter is avoided, loss is reduced, the service life is prolonged, power matching and stable transmission are achieved, reactive loss is reduced, bus voltage is stabilized, harmonic waves can be reduced, the electric energy quality is improved, and efficient and stable operation of the micro-grid is guaranteed.

The invention discloses a converter grid following-grid construction control mode smooth switching method suitable for wide-range source-grid state change. The method comprises the following steps: constructing a phase-locked loop control loop, a power outer loop control loop and a current inner loop control loop of a grid following type converter based on constant power control; constructing a voltage control loop, a phase control loop and a voltage and current double-closed-loop control loop of the network construction type converter based on the virtual synchronous generator VSG; calculating real-time output active power P and reactive power Q of the converter; constructing a voltage phase synchronization loop switching control loop and a current instruction tracking loop, and realizing smooth switching of dq-axis current instruction values output by a power outer loop of a following network type and a voltage outer loop of a construction network type; and the output dq-axis current instruction value is transmitted to a current inner loop to generate a final voltage signal, and a PWM wave is output to the converter through a modulation link. According to the method, a voltage phase synchronous switching compensation mechanism is adopted, a voltage amplitude and a phase signal are synchronously corrected in the mode switching process, and smooth change of an inner ring current reference signal is achieved.

The invention discloses a low-harmonic high-voltage speed regulation system based on a multi-pulse phase-shifting transformer, and particularly relates to the field of power electronic technology and motor speed regulation, which is characterized in that the primary side of the multi-pulse phase-shifting transformer is in star connection, and N groups of windings on the secondary side are in extended delta connection, so that phase difference is realized; the multi-path low-voltage alternating current is converted into multi-path low-voltage alternating current and low-order harmonics are High voltage is output through cascade H-bridge topology series connection, and reliable conversion is guaranteed through rectification filtering inversion and device redundancy design; the motor control module collects signals through multiple sensors, and PWM drive signals are generated through a vector control algorithm and coordinate transformation. The harmonic detection and compensation module detects harmonic waves based on an FFT algorithm, and injects a reverse compensation component through a modulation strategy to offset the harmonic waves; and the auxiliary protection module integrally realizes low-harmonic and high-precision high-voltage motor speed regulation through multi-dimensional monitoring and hardware protection.

The embodiment of the invention discloses a multiplex type three-stage starting power generation controller, and relates to the technical field of aviation three-stage starting power generators. In the starting stage, an H-bridge inverter in the starting power generation controller provides single-phase alternating-current exciting current for a main exciter stator exciting winding through SPWM modulation so as to establish a pulsating magnetic field to provide exciting current for a main motor, and a three-phase full-bridge inverter provides armature current for a main motor stator armature winding through SVPWM modulation. In a power generation stage, an anti-parallel diode of the three-phase full-bridge inverter is used as a rectification circuit of the auxiliary exciter, and the H-bridge inverter adopts a PWM chopping mode to operate as an asymmetric half-bridge circuit. A power generation controller and a starting controller are integrated into a whole, and by changing the modulation mode of a hardware circuit, the control function of the three-stage starting generator at different stages can be realized by only one controller, so that the structure of the starting power generation controller is simplified, the system integration degree of the three-stage starting generator is improved, and the volume and the weight of the system are reduced.

An assembly and method are disclosed for generating and detecting a modulated pressure signature in a fluid transported to a subsurface injection zone. The assembly includes a pump, a pulsation dampener, and a pressure modulation device that oscillates pressure to produce a frequency-modulated signature in the fluid, resulting in an alternating current streaming potential (AC-SP) at the injection zone. The method includes recording modulated electromagnetic signals at an array of electromagnetic field receivers on a surface above the subsurface injection zone, processing the data to identify source frequency signals, and correlating these signals to image subsurface fluid or pressure distribution, enabling three-dimensional mapping of subsurface structures.

A control system for an electric motor of an electrified vehicle includes an inverter of the electrified vehicle, the inverter comprising a set of switches and being configured to receive three pulse-width modulation (PWM) signals and to control the set of switches to generate an alternating current (AC) output voltage from a direct current (DC) link voltage provided by a battery system of the electrified vehicle, and a control system configured to determine a torque command for the electric motor, determine commanded d-axis and q-axis voltages based on the torque command, generate a trapezoidal wave modulating signal for carrier-based PWM based on the commanded d-axis and q-axis voltages, generate the three PWM signals by performing carrier-based PWM using the trapezoidal wave modulating signal, and control the electric motor using the AC output voltage generated by the inverter.

The application belongs to the technical field of power electronic control, and particularly relates to a kind of energy storage converter parallel control method and system.The method comprises: after Clark transformation, Park transformation of three-phase voltage signal and three-phase current signal output by inverter, active power and reactive power are calculated;Reference value of voltage loop and current loop is calculated, and prediction value is superimposed on current loop to obtain direct axis front end voltage and cross axis front end voltage, and then direct axis voltage and cross axis voltage are calculated;Direct axis voltage and cross axis voltage are subjected to SPWM modulation, and inverter bridge arm switch tube is driven to turn on and off to control inverter output.The prediction value superimposed in the application can quickly compensate the reference value required by current loop when load mutates, and then maintain the stability of voltage.

The invention relates to the technical field of multimode interference, and provides a central wavelength tunable multimode interference device which comprises an input waveguide region, a multimode interference region and an output waveguide region which are connected in sequence, the multimode interference region comprises a core layer, the core layer is made of a high-refractive-index material, and the output waveguide region is made of a high-refractive-index material. And a modulation electrode structure for modulating the refractive index of the core layer is arranged on the multimode interference region. The invention further provides a manufacturing method of the multimode interference device with the tunable central wavelength and a coherent modulator. Refractive index modulation is carried out on the core layer of the multi-mode interference area through the modulation electrode structure, in the multi-mode interference area, the effective refractive index directly determines the self-mapping point positions of different wavelengths, therefore, the effect of tunable central wavelength can be achieved through refractive index modulation, and through selection of different bias voltages, the tunable wavelength of the multi-mode interference area can be achieved. And the output effect of the optical power in the output waveguide is tuned.

An oxidation corrosion product thickness on-line measurement method based on a photoacoustic effect comprises the following steps: modulating laser with a specific frequency to irradiate on the CRUD surface of a fuel cladding, monitoring an acoustic wave signal emitted by the CRUD surface by using a piezoelectric sensor, and establishing an on-line conversion model of the acoustic wave signal and the CRUD thickness so as to obtain visual thickness real-time data. On the condition that the original environment of the CRUD is not damaged, online in-situ measurement is carried out on the thickness of the CRUD, and it is ensured that the real thickness of the CRUD in the growth environment can be accurately reflected by measurement data. Through the method, the dynamic growth behavior characteristics of the CRUD thickness can be obtained, so that more accurate monitoring and guidance are provided for safe operation and fuel management of a reactor.

The invention discloses a boost converter and a transient response circuit and a control method thereof, and relates to the technical field of switching power supplies, and the boost converter comprises a voltage detection circuit and a control circuit. The circuit comprises a voltage detection circuit and a control circuit, and the voltage detection circuit can monitor abnormal drop or overshoot of the output voltage in real time and immediately generate a level signal. The control circuit responds to the signal and provides a'lead 'or'lag' correction value for the feedback control circuit by modulating the reference voltage, so that the response delay of the system is effectively compressed, and the recovery process of the output voltage is accelerated. On the premise that the original bandwidth and phase margin of a main loop are not changed, the transient response speed is increased, the recovery process of a system is accelerated, and the contradiction that stability and fast transient response cannot be considered at the same time due to zero point limitation of a right half plane of a traditional boost converter is solved.

The application discloses a modulation and control method for improving short-time overload capacity of an ANPC topology. In view of the problem that the overload capacity improvement method of the existing grid-connected converter of the ANPC topology is high in cost and poor in universality, the application actively reduces the switching frequency, an operating parameter, at the software algorithm level, effectively reduces the output loss of the grid-connected converter in the overload operating state, and effectively improves the short-time overload operating capacity of the grid-connected converter by switching the modulation mode to effectively uniformly distribute the switching loss of each device without substantially increasing the cost and performance of the grid-connected converter.

The application discloses an online measurement method for the thickness of oxidation corrosion products based on the photoacoustic effect, which comprises the following steps: modulating laser irradiation of a specific frequency on the CRUD surface of a fuel cladding, monitoring the sound wave signals emitted by the CRUD surface by using a piezoelectric sensor, and establishing an online conversion model of the sound wave signals and the CRUD thickness, so that intuitive real-time thickness data can be obtained. The thickness of the CRUD is measured online and in situ without destroying the original environment of the CRUD, so that the measurement data can accurately reflect the real thickness of the CRUD in the growth environment. Through the method, the dynamic growth behavior characteristics of the CRUD thickness can be obtained, so that more accurate monitoring and guidance can be provided for the safe operation and fuel management of a reactor.

The invention discloses a modulation and control method for improving the short-time overload capacity of ANPC topology. Aiming at the problems of high cost and poor universality of the existing method for improving the overload capacity of the grid-connected converter of the ANPC topology, the method disclosed by the invention effectively reduces the output loss of the grid-connected converter in an overload operation state by actively reducing an operation parameter, namely switching frequency, on a software algorithm level; and the switching loss of each device is effectively and uniformly switched through a modulation mode, so that the short-time overload operation capability of the grid-connected converter is effectively improved on the premise that the cost and the performance of the grid-connected converter are not greatly improved.

The invention discloses a motor linear overmodulation method and device, a vehicle and a storage medium, and the method comprises the steps: obtaining a reference voltage component and a DC bus voltage of a motor, and obtaining a reference voltage amplitude and a reference voltage phase angle according to the reference voltage component; a modulation coefficient is obtained according to the reference voltage amplitude and the direct-current bus voltage, the working area of the motor is judged according to the modulation coefficient, and the working area is divided into a linear modulation area, an overmodulation I area and an overmodulation II area according to the modulation coefficient; and when the working area is the overmodulation II area, obtaining a dynamic weight coefficient according to the reference voltage phase angle, and controlling the motor according to the dynamic weight coefficient. Therefore, when the working area of the motor is the overmodulation II area, the motor is controlled according to the dynamic weight coefficient obtained by the voltage phase angle, so that the voltage jump of the overmodulation II area is eliminated, the power performance of the electric vehicle driving system is improved to the maximum extent, and meanwhile, the output smoothness is ensured.

The class AB amplifier device includes an input chopper switch circuit that performs a chopping operation in synchronization with a first and second chopper clock signal, and outputs first and second modulated signals obtained by modulating the first and second differential input signals to a first and second node; an input amplifier circuit that receives the first and second modulated signals via the first and second nodes, and outputs a differential amplified signal obtained by amplifying the first and second modulated signals; an output chopper switch circuit that receives the differential amplified signal, performs a chopping operation in synchronization with the first and second chopper clock signals, and modulates the differential amplified signal to output a demodulated signal demodulated to the frequency band of the first and second differential input signals; and an output amplifier circuit that outputs a first output signal obtained by amplifying the demodulated signal.

The invention provides a communication method and device, and the method comprises the steps: generating an auxiliary synchronization signal which is a signal obtained based on a first sequence; the waveform of the auxiliary synchronization signal is a single carrier waveform; and sending the secondary synchronization signal. Wherein the first sequence is determined according to the second sequence, the lengths of the first sequence and the second sequence are L, and an element d (m) of the second sequence and an element x (n) of the first sequence meet the following conditions: m = (n + c) modL, 0 < = n < L, 0 < = m < L, and d (m) = 0, 1, 2 or 3; c is p * ID. In the method, the first sequence satisfying the form has low cross correlation after being modulated, and the waveform of the auxiliary synchronization signal is a single carrier waveform, so that the PAPR performance of the auxiliary synchronization signal can be improved, the PAPR of the auxiliary synchronization signal can be reduced, and the coverage range of the auxiliary synchronization signal can be improved.

The invention relates to the technical field of soft start control of resonant converters, in particular to a soft start control method of a CLLC resonant converter with a short-circuit protection function, which comprises the following steps: S1, establishing a time domain model of the CLLC resonant converter; s2, calculating an output frequency based on the actual output of the CLLC resonant converter through a PI controller; s3, building a gain-minimum frequency curve based on the time domain model of the CLLC resonant converter, and obtaining the minimum switching frequency based on the voltage gain of the CLLC resonant converter; s4, determining the switching frequency based on the output frequency and the minimum switching frequency; and S5, a driving signal is calculated based on the switching frequency through a PWM modulator, and the CLLC resonant converter is driven, so that the peak resonance current of the CLLC resonant converter does not exceed a set value. According to the invention, the peak resonance current of the CLLC resonant converter can be limited not to exceed the set value, and the peak current control is realized in the starting and operating processes, so that the peak of the resonance current can be accurately limited under all working conditions.

The present invention relates to the technical field of wireless communications, and provides a communication circuit, method, apparatus, and system. The communication circuit comprises a modulation element, an energy convergence network, and a second resonant network. The modulation element disperses energy of a first microwave signal at a first frequency at a first port and transmits same to an energy network via a second port. The energy convergence network converges the dispersed energy to obtain a second microwave signal. The second resonant network performs secondary frequency selection on the second microwave signal and generates an oscillation signal at a second resonant frequency, and transmits the oscillation signal to the modulation element via a third port to mix with the first microwave signal, thereby obtaining a frequency-converted signal at a second frequency. The present invention provides multiple signal transmission paths from the energy convergence network to the second resonant network that bypass the modulation element, thereby reducing the loss of the second microwave signal and acquiring a frequency-converted signal with increased power, and correspondingly lowering the transmit power requirements of a transceiver apparatus and the microwave drive power threshold of the communication circuit.

A control system for an electric motor of an electrified vehicle includes an inverter of the electrified vehicle, the inverter comprising a set of switches and being configured to receive three pulse-width modulation (PWM) signals and to control the set of switches to generate an alternating current (AC) output voltage from a direct current (DC) link voltage provided by a battery system of the electrified vehicle, and a control system configured to determine a torque command for the electric motor, determine commanded d-axis and q-axis voltages based on the torque command, generate a rectangular wave modulating signal for carrier-based PWM based on the commanded d-axis and q-axis voltages, generate the three PWM signals by performing carrier-based PWM using the rectangular wave modulating signal, and control the electric motor using the AC output voltage generated by the inverter.

a conversion unit that calculates a duty cycle corresponding to each of the plurality of pulse-width modulated signals in dependence on the instruction; a gain unit that selects a gain that produces a linear relationship between the required voltage of the pulse-width modulated signal and the voltage achieved by the plurality of pulse-width modulated signals, even when the required voltage of the pulse-width modulated signal is in an overmodulation region, and applies the gain to each of the duty cycles to produce an adjusted duty cycle; and an output unit that outputs the adjusted duty cycle for generating the plurality of pulse-width modulated signals.

A method (100) for determining a power dissipation value of an electronic power circuit during an electrical period of a modulated control signal is disclosed, comprising: determining a linear mean switching energy value (110) of the electronic power circuit based on a modulated control signal with linear modulation; determining a nonlinear mean switching energy value (120) of the electronic power circuit based on a modulated control signal with nonlinear modulation, in particular overmodulation; determining a scaling factor value (130) based on the linear mean switching energy value and the nonlinear mean switching energy value; and determining the power dissipation value (140) based on the linear mean switching energy value and the scaling factor value.Furthermore, a computing unit designed and equipped to execute the procedure (100) is disclosed.

A photovoltaic air conditioner and its DC component suppression method, electronic equipment, and dielectric are disclosed. The suppression method includes: building a bus ripple detection circuit on the DC side of a single-phase inverter to obtain bus ripple sampling results; performing primary compensation of the DC component by generating a compensation current based on the DC bus voltage; subtracting the current from the collected actual grid-connected current to obtain a grid-connected current error value, which is then combined with a grid voltage feedforward signal and a capacitor current feedback signal to generate a duty cycle signal, which drives the inverter through SPWM modulation; performing secondary compensation of the DC component by using a SOGI-PLL with an FLL to perform phase tracking of the grid voltage and generate a phase-synchronized current modulation signal; adding this signal to the difference between the current and the current to obtain a compensation signal, which adjusts the inverter's duty cycle. This invention effectively reduces the grid-connected DC component of a photovoltaic household air conditioner.

The invention discloses an ultrasonic backscattering type metal-separated signal and energy wireless simultaneous transmission system and method, the system comprises a transmitting end and a receiving end, the transmitting end comprises a signal generation device, a power amplification circuit, a first impedance matching circuit and an ultrasonic transmitting transducer which are arranged in sequence; the first impedance matching circuit is used for ensuring conjugate matching of load impedance and source impedance of the transducer and realizing maximum power transmission, and the ultrasonic transmitting transducer is used for converting an electric signal into mechanical vibration by utilizing an inverse piezoelectric effect and generating ultrasonic waves; the receiving end is arranged in the closed metal and comprises an ultrasonic receiving transducer, a second impedance matching circuit and a rectifying, voltage stabilizing and energy collecting circuit which are arranged in sequence; and the ultrasonic receiving transducer end converts the received ultrasonic waves into electric energy by utilizing a direct piezoelectric effect and controls the reflectivity of an incident carrier wave through OOK modulation to transmit a binary signal to the transmitting end. The system is simple in structure and low in power consumption, and synchronous transmission of energy and data is achieved.

The invention discloses a permanent magnet synchronous motor torque ripple suppression method based on SVPWM (Space Vector Pulse Width Modulation) overmodulation region optimization, and belongs to the technical field of power generation, power transformation or power distribution. The method comprises the following steps: establishing a table look-up model of torque about shaft current and rotor position and an equal-torque line cluster; a stator current instruction model containing multiple harmonic components is constructed, a harmonic current coefficient is used as a decision variable, and a multi-objective optimization function considering torque ripple minimization, voltage vector angle alignment constraint, voltage vector amplitude minimization and maximum current and voltage constraint at the same time is established; and solving by adopting an optimization algorithm to obtain an optimal harmonic current coefficient, and generating a current instruction to drive the motor to operate. By optimizing the current track, the output voltage vector required by the inverter is matched with the maximum output capability point of the SVPWM overmodulation area, the torque fluctuation is effectively suppressed, the requirement for the direct current bus voltage is remarkably reduced, and the system voltage utilization rate and the operation stability are improved.

Embodiments of the present application disclose a kind of overmodulation processing method, device, electronic equipment and storage medium.The method comprises: obtaining the initial voltage output by current regulator, and determining the initial voltage state of the initial voltage;In the case where it is determined that the initial voltage state is transient saturation state, a preset adjustment angle is obtained, and the target voltage direction of the initial voltage in overmodulation process is determined based on the preset adjustment angle;Determine the limit voltage of the initial voltage on the voltage hexagon circumscribed circle, and determine the target voltage output after overmodulation of the initial voltage based on the limit voltage.The technical scheme disclosed in the embodiments of the present application improves the accuracy of the output result after overmodulation by considering the case where the voltage is in transient saturation, thereby improving the dynamic response of the vehicle control system.

The invention discloses an interference technical scheme based on GMSK signal characteristics, and relates to the technical field of wireless communication interference. According to the scheme, firstly, differential coding is carried out on a binary random code to obtain a relative code, then a GMSK baseband signal is generated through GMSK modulation, and carrier modulation is carried out; the method is characterized in that a self-adaptive phase modulation forwarding interference signal generation mechanism is designed based on the characteristics of constant envelope and continuous phase change of GMSK signals, and interference signals are generated by constructing a time-varying amplitude disturbance model, a dynamic time delay model and an interference phase model; and finally, superposing the interference signal with the GMSK signal passing through the Gaussian white noise channel to realize effective interference on the GMSK communication signal. According to the method, the GMSK signal characteristics are fully utilized, the interference pertinence is high, the interference effect on a GMSK communication system can be remarkably improved, the interference parameters can be flexibly adjusted according to actual scenes, and the applicability is wide.

The application discloses a kind of modular multilevel converter double-port network configuration control method belonging to the technical field of converter control.It includes the following steps: obtaining MMC AC output voltage additional amount Δu ac,d / q , and then calculating the reference value u ac,ref,d / q of MMC AC side output voltage;Obtaining MMC DC output voltage additional amount Δu dc , and then calculating the reference value u dc,ref of MMC DC side output voltage;u ac,ref,d / q And u dc,ref Respectively sent to AC side and DC side voltage and current double closed loop control link, respectively obtain MMC modulation signal differential mode amount u diff,d / q And common mode amount u sum,j At the output end of two links;According to u diff,d / q And u sum,j , using bridge arm output voltage reference value calculation method to obtain the expected value of MMC bridge arm capacitor module output voltage, and then generate the trigger pulse signal of all switching devices in MMC through modulation part.The application is simple to operate, low in computing resource requirement, high in control algorithm implementability and strong in engineering applicability.

The invention relates to the technical field of inverter pulse width modulation, and particularly provides a random pulse width modulation method and system and a storage medium, and the method comprises the steps: collecting an initial bus voltage and a three-phase current based on an ADC module; solving a difference between the initial bus voltage after filtering and the initial bus voltage before filtering to obtain a random number seed; calculating to obtain a random number; calculating a three-phase voltage based on the three-phase current, and performing sector judgment to obtain a maximum voltage value and a minimum voltage value in different sectors; calculating an overmodulation phase voltage based on the voltage maximum value and the voltage minimum value; calculating a common-mode voltage based on the initial bus voltage, the random number, the maximum voltage value and the minimum voltage value; injecting the common-mode voltage into the over-modulation phase voltage to obtain a three-phase modulation voltage, and performing normalization processing to obtain a modulation voltage; and carrying out carrier period distribution based on the modulation voltage to obtain conduction time of upper and lower bridge arms. The random number calculation is simplified, the carrier frequency does not need to be changed when the electromagnetic noise is reduced, and the consumed calculation resources are less.

A method for the servo control of an optical device includes a cavity exhibiting resonance around a center frequency ƒc, a laser and a phase modulator, the method being designed to servo-control the cavity to the laser or vice versa and to compensate for an amplitude modulation introduced by the phase modulator, the method comprising, inter alia, the following steps: A. varying a difference δν between the optical frequency of the laser radiation and the center frequency, such that the optical frequency scans the resonance, the difference being controlled by a parameter of an element of the device, and for each difference δνi i. modulating, at a modulation frequency ƒmod, a phase of the laser radiation, through a modulation phase φmod, with the phase modulator, ii. injecting the phase-modulated radiation into the cavity, iii. using a photodiode to detect radiation reflected or transmitted by the cavity and generating an electrical signal (St, Sr) representative of the intensity of the detected radiation, iv. demodulating the electrical signal at the modulation frequency ƒmod by synchronously generating a first demodulated signal and a second demodulated signal representative of the demodulated electrical signal, respectively at a first demodulation phase φdem,1 and at a second modulation phase φdem,2φdem,2≈φdem,1k, where k∈[0; 2π] is different from the first phase, and by filtering the first and the second signal so as to retain only a DC component of the first demodulated signal Vϵ1, called error signal 1, and of the second demodulated signal Vϵ2, called error signal 2.

The invention provides an output shaft of a screwdriver and an electric tool, and relates to the technical field of electric tools. An output shaft of the screwdriver is used for driving a workpiece to rotate and provided with a signal transmitting module and a transmitting coil. The signal transmitting module comprises a signal transmitting circuit used for collecting an analog signal, performing digital processing on the analog signal to generate a digital signal, and generating a control signal according to the digital signal; the load effect circuit is connected with the signal transmitting circuit and is used for adjusting the load state of the transmitting coil by controlling the on and off of a switching device according to the control signal so as to generate a modulated pulse signal represented by an electromagnetic signal in the transmitting coil; and the transmitting coil wirelessly transmits an electromagnetic signal to the signal receiving module in an electromagnetic induction mode. According to the scheme, the transmission mode that analog signals are subjected to digital processing and then modulated is adopted, the transmission precision of sensor signals is improved, and high-precision and high-stability dynamic signal transmission in the screwdriver is achieved.