98 results about "Carrier synchronization" patented technology

The invention discloses a communication-detection integrated sonar signal design method and device based on multi-pulse composite modulation, and the method comprises the steps: dividing a total frame period into a detection sub-frame and a communication sub-frame, enabling the detection sub-frame to achieve the high-resolution distance measurement through employing a bidirectional linear frequency modulation (BILFM) signal, a communication sub-frame adopts a multi-frequency multi-phase composite modulation (MTPM) signal to realize high-bit-rate data transmission; after band filtering, orthogonal demodulation, low-pass filtering and down-sampling preprocessing are carried out on detection sub-frame echoes, distance and speed information is extracted by adopting fast-time low-sampling two-dimensional fast Fourier transform (2D-FFT), unambiguous Doppler frequency is recovered by utilizing the Chinese remainder theorem (CRT), and accurate speed measurement of long-distance and high-speed targets is realized; a communication subframe receiving signal is subjected to IQ demodulation after down-conversion, Costas loop carrier synchronization and matched filtering, and multi-frequency multi-phase coded data are extracted. According to the method, the time-frequency collaborative design of detection and communication is realized, the distance resolution and the speed measurement range are considered, and the signal bandwidth utilization rate and the underwater information transmission reliability are remarkably improved while the system complexity is kept low. The device comprises a processor and a memory, and an executable program for implementing the method is stored in the memory. The technology can be widely applied to the fields of unmanned underwater vehicles, ocean monitoring, underwater sensing networks and the like.

This application provides an inverter carrier synchronization system, belonging to the field of inverter control technology. The system includes multiple inverter devices connected via cascaded communication. Each inverter device includes a CPLD unit, a drive unit connected to the CPLD unit, a fault output unit, and a fault identification unit. The CPLD unit generates or forwards a carrier synchronization signal. The first contact of the relay in the fault output unit outputs a fault status signal to the next-level inverter device. The first-level inverter device acts as the master, and the fault status signal output by any normal inverter device is low. When any inverter device loses power or malfunctions, its relay disconnects, causing the output fault status signal to be high. Upon detecting the high-level fault status signal, the next-level inverter device automatically switches to become the master of the downstream inverter device. This system effectively suppresses high-frequency circulating currents in the system, improving system operating efficiency and stability.

The invention discloses a communication physical link multi-protocol sharing method during parallel operation of energy storage converters. The method is based on two general physical links, and efficient sharing of multiple protocols is achieved through the steps of hardware standardization integration, protocol intelligent adaptation, automatic switching of a drive circuit and the links, protocol signal two-way transmission, real-time state monitoring and the like. A unified adaptation platform is built on the hardware level, a multi-protocol special drive circuit and a high-performance MCU are integrated, the protocol level supports dynamic switching and parallel work of multiple protocols such as CAN, I2C, RS485, RJ45 and carrier synchronization signals, and scene changes can be responded without changing hardware. And during operation, through a full-dimension state monitoring and redundancy protection mechanism, transmission stability and rapid fault recovery are guaranteed. Redundant configuration of a special link and a driving circuit is reduced, the space utilization rate of a circuit board and the flexibility of the system are improved, and the diversified communication requirements of large-scale parallel connection of the energy storage converter can be quickly met.

The invention discloses an encryption burst communication receiving method based on an FPGA, and belongs to the technical field of burst communication. According to the invention, the problems of poor synchronization performance and poor anti-interference capability at the receiving end in the existing method are solved. According to the method, the carrier synchronization range is expanded by introducing the pilot frequency to enable the synchronization heads to be '1', the limitation that a conventional frequency offset estimation algorithm can only work under the condition that the Doppler frequency shift is smaller than 0.5 times of the symbol rate is broken through, and the capacity of the system for adapting to the high-dynamic environment is improved. A spreading code continuous tracking working mode is designed, coarse estimation and synchronization are carried out in a frame header part, spreading codes are still adopted in an information part, and continuous tracking is carried out, so that the system can adjust the phase of the spreading codes in real time in the whole frame to solve the problem of phase error accumulation caused by adopting a low-precision clock; the problems that when one frame of data at the sending end is long, the synchronization performance is reduced when a low-precision clock is adopted, and even effective synchronization cannot be achieved are solved. The method can be applied to the field of burst communication.

The invention provides a signal-to-noise ratio estimation method and device suitable for PSK (Phase Shift Keying) modulation. The method comprises the following steps: calculating the average power of an input signal sequence; estimating the average power of the pilot frequency sequence; and calculating a signal-to-noise ratio. According to the method, the influence degree of noise on the distance between the PSK modulation signal and the original point in the constellation diagram is estimated, a traditional method for calculating the signal-to-noise ratio by estimating the deviation degree of the actual signal from the ideal signal due to the influence of noise is replaced, high accuracy can still be kept when the signal is influenced by Doppler frequency deviation and sampling deviation, the method is more suitable for an actual communication system, and compared with the prior art, the method has the advantages of simple operation and low cost. In an actual communication system, signal-to-noise ratio estimation is usually carried out after signal timing synchronization and carrier synchronization processing, however, the signal-to-noise ratio calculation method provided by the invention can be used for estimating the signal-to-noise ratio after synchronization before synchronization according to PSK modulation characteristics, and has certain application advantages in scenes such as switching modulation waveforms according to the signal-to-noise ratio.

The invention discloses an interference communication integrated waveform generation method based on spectrum dispersion-multi-system phase shift keying. The problems of difficult communication information demodulation and high hardware implementation complexity in interference communication integration research are mainly solved. According to the scheme of the invention, the SMSP interference signal is formed by periodically expanding the chirp signal on the time domain, the communication information is modulated on the phase of the chirp signal, and the plurality of chirp signals carrying the communication information can cause dense false target interference at random positions on the radar, so that the interference and communication integrated signal is generated. At a communication receiving end, a first linear frequency modulation signal is adopted to perform carrier synchronization, so that the synchronization effect can be improved by using the high time width-bandwidth product characteristic of the linear frequency modulation signal, and communication information can be demodulated directly by using a coherent demodulation mode; at a radar receiving end, the signal can generate a radar interference effect with dense false target characteristics.

The invention discloses an angle error demodulation method for a burst communication signal, and relates to the field of satellite random access. According to the invention, angle error demodulation of burst communication signals is realized through synchronous sequence detection, open-loop AGC control and frequency domain angle error calculation. The arrival of a burst signal and the starting boundary of the signal are determined through synchronous sequence detection, signal power is quickly estimated through open-loop AGC control, AGC coefficient adjustment is carried out, a sum path signal is kept at a constant level, and angle error demodulation is directly carried out in a frequency domain through frequency domain angle error calculation on the basis that carrier synchronization does not need to be established. The method is suitable for angle error demodulation of burst signals with short signal duration and unfixed signal intervals, carrier synchronization does not need to be established, and the applicable signal modulation system is wide.

The present application belongs to the technical field of very low frequency fluctuation detection, and discloses a very low frequency station signal information extraction method and system based on a phase-locked loop. The present application amplifies and samples a wide frequency signal containing a very low frequency station transmitting signal, sets local MSK demodulation parameters, uses phase-locked loop technology to respectively perform carrier synchronization on the upper and lower frequencies of the MSK modulated signal transmitted by the target monitoring very low frequency station, extracts a baseband synchronization signal and a carrier synchronization signal from the phase-locked loops of the upper and lower frequencies, respectively, calculates the amplitude information of the upper and lower frequencies using the baseband synchronization signal, and further obtains the amplitude information of the target monitoring very low frequency station. The carrier synchronization signals of the upper and lower frequencies are used to extract the frequency of the carrier synchronization signal of the MSK modulated signal transmitted by the target monitoring very low frequency station, and further extract the phase offset information of the target monitoring very low frequency station. The present application can improve the accuracy of very low frequency station signal information extraction.

The invention discloses a generator parallel operation control method and system based on carrier synchronization, and belongs to the technical field of power electronic conversion. A generator parallel operation control method based on carrier synchronization is characterized in that the method is applied to a system comprising a synchronous enabling unit, a synchronous signal transmitter and a plurality of parallel converters connected with the synchronous enabling unit and the synchronous signal transmitter respectively, and the method comprises the following steps: for each converter, determining a counting difference value and sending the synchronous enabling unit; the synchronous enabling unit feeds back an adjusting signal to the corresponding converter based on a comparison result of the difference value sent by the carrier wave processor of each converter and a count value threshold until the difference values sent by the carrier wave processors of all converters are smaller than the count value threshold; then, synchronous enable signals are sent to the converters respectively; and each converter drives the IGBT to realize current conversion based on the synchronous enable signal. According to the method, synchronous impact and circulation are reduced by simulating dynamic approximation of a carrier and an actual carrier.

The invention discloses a service-adaptive satellite-borne non-uniform multicarrier demodulation device, and belongs to the field of digital signal processing. The method comprises the following steps of: firstly, performing orthogonal down-conversion and resampling filtering processing on a digital intermediate frequency signal sampled by an ADC (Analog to Digital Converter), processing the digital intermediate frequency signal by a non-uniform channelization splitter, and then serially outputting the digital intermediate frequency signal to a spread spectrum ratio self-adaptive variable burst capturer according to fixed quadruple sampling to capture a leading head and identify the spread spectrum ratio; the method comprises the following steps: completing symbol synchronization and de-spreading processing on an input signal according to a spread spectrum ratio, then completing carrier coarse synchronization and pattern word identification, completing modulation mode identification and carrier synchronization according to a pattern word, performing channel decoding through a multi-mode decoder to recover to an information bit stream, and outputting the information bit stream. And the information bit stream is sent to a service frame recombination processor for search identification and recombination splicing, and output is carried out after whole-frame CRC check is carried out. The method has the advantages of flexibility in use, low resource occupation and capability of realizing adaptive demodulation of variable-rate, multi-modulation-mode and multi-coding-mode service transmission signals without parameter configuration.

The application provides a carrier frequency synchronization method applied to a frequency hopping data transmission system, the frequency hopping data transmission system comprising a transmitting end and a receiving end, and the method comprises the following steps: the transmitting end processes to-be-sent data into a data frame, adds a pilot head based on a ZC sequence to the data frame to form a frequency hopping data transmission frame, and sends a radio frequency signal carrying the frequency hopping data transmission frame to the receiving end; the receiving end acquires the radio frequency signal, processes the radio frequency signal into a digital signal; carrier synchronization processing is performed on the digital signal, carrier frequency scanning is performed on multiple frequency hopping points to screen effective communication frequency points; the starting position of the data frame is determined according to the effective communication frequency points, data demodulation and decoding are performed on the data frame, and original data is recovered. Through the application, the excellent autocorrelation characteristics of the ZC sequence and the intelligent double-peak detection mechanism are utilized to realize carrier frequency synchronization without strict time synchronization, and fast and anti-interference data transmission is completed.

This application discloses a receiver positioning method, apparatus, communication system, storage medium, and electronic device, relating to the field of satellite navigation technology. The method includes: determining second information after signal recovery based on first information before signal loss of the satellite; tracking the signal based on a carrier digitally controlled oscillator frequency control word, a code digitally controlled oscillator frequency control word, and a code start point to determine the frequency error; during signal tracking, detecting whether the second code phase is aligned by code phase sliding; and, in response to the frequency error being within a preset range, the second code phase being aligned, and carrier synchronization, performing navigation calculations based on code epoch values ​​and the tracked third code phase to position the receiver. This application solves the technical problems in related technologies where repositioning of lost-lock signals cannot be achieved in weak signal scenarios, and the repositioning time is slow.

The invention relates to an IGCT (integrated gate commutated thyristor) power unit parallel dynamic current sharing system and method, which ensure the carrier synchronization consistency of each inverter module by constructing a high-precision synchronous clock signal with an error less than 10ns, thereby reducing the difference of switching moments; meanwhile, the high dominant frequency operational capability of 50MHz of a field programmable gate array (FPGA) hardware chip is utilized, and the PWM pulse width adjusting quantity with the resolution reaching 20ns is output, so that accurate adjustment of multi-machine parallel current is realized. Compared with a conventional current sharing method, the current sharing method has the advantages that the output current of each module can be accurately adjusted with high real-time performance, the problem of poor active adjusting capability in the prior art is effectively solved, and the current sharing performance and the system reliability of the high-power parallel device are remarkably improved.

The invention provides a power electronic transformer carrier synchronization control method and system based on a DBA topological structure, and the method comprises the steps: carrying out the time domain feature extraction processing through obtaining a switching signal waveform, generating an initial synchronization reference sequence, obtaining the magnetic flux change rate data of a high-frequency transformer, and carrying out the time domain feature extraction processing; the method comprises the following steps: carrying out characteristic correlation on an initial synchronous reference sequence to obtain a carrier period correlation degree and a phase difference distribution curve, generating a matching parameter of a carrier period and a phase based on the two curves, obtaining parallel circulating current amplitude data of a target loop, carrying out segmented threshold determination, and obtaining a circulating current amplitude overrun interval and an amplitude change gradient; and generating a frequency adjustment parameter based on the two, fusing the frequency adjustment parameter and the system operation state data to obtain a fused feature vector, performing phase alignment information reconstruction, generating reconstructed phase alignment information, and generating a multi-stage synchronous control instruction based on the reconstructed phase alignment information to control a switch time sequence. The carrier synchronization precision and the system operation stability of the power electronic transformer are improved.

The application discloses a kind of based on dual three-dimensional memory hyperchaos SCMA-OFDM transmission system, the system includes sending end and receiving end, the user of sending end possesses respective codebook, J user shares K subcarrier, initial bit information and after the calculation of hyperchaos model of memristor triangle mapping chaotic codebook enter SCMA encoder and carry out codebook mapping processing, obtain encrypted SCMA-OFDM signal, for carrier synchronization, it is inserted pilot, after pilot, obtain frequency domain signal and information data using fast inverse fourier transform after the calculation of hyperchaos model of memristor triangle mapping, frequency domain signal is changed into time domain signal;Then to time domain signal is increased cyclic prefix CP and cyclic suffix CS to eliminate intercarrier interference, then parallel-serial conversion parallel signal is changed into serial signal, finally through up-conversion DUC complex signal mixing becomes real signal into transmission channel.The transmission system of regular hexagon chaotic codebook, its performance is improved by 2.5dB than traditional codebook.

The invention discloses a high-spectral-efficiency and high-speed FTN (Fourier Transform Network) transmission method based on pseudo code auxiliary carrier synchronization, which belongs to the field of high-frequency wireless communication, and comprises the following steps: a transmitting end composites a low-speed pseudo code pilot signal into a high-speed FTN signal by adopting a frequency division multiplexing mode to obtain a composite signal and outputs the composite signal; a receiving end performs down-conversion on the received composite signal, and the composite signal is separated by a filter to obtain a low-speed pseudo code pilot frequency sequence and a high-speed FTN sequence; carrying out carrier frequency offset estimation based on the low-speed pseudo code pilot frequency sequence to obtain a frequency offset estimation value; performing frequency offset compensation on a receiving end carrier by adopting the frequency offset estimation value to obtain a compensated high-speed FTN sequence; and carrying out symbol estimation on the compensated high-speed FTN sequence by adopting a forward backtracking continuous symbol sequence detection algorithm to obtain a received signal. According to the invention, the receiving sensitivity and the system robustness can be ensured while high-spectrum-efficiency transmission is realized.

The invention discloses a cascade frequency converter current-sharing and voltage-sharing control method, and belongs to the technical field of frequency converters. The cascaded frequency converter current-sharing and voltage-sharing control method comprises the following steps: S1, current-sharing control; and S2, performing voltage-sharing control. The maximum or minimum frequency converter is selected as a master frequency converter according to the ID numbers, other frequency converters are selected as slave frequency converters, the master frequency converter sends modulation waves to each slave frequency converter through RS485, and then the master frequency converter sends carrier synchronization signals to each slave frequency converter; after receiving a carrier synchronization signal, the slave frequency converter begins to compare the carrier synchronization signal with a modulation wave to generate PWM, and the master frequency converter calculates communication delay to ensure carrier synchronization with the slave frequency converter so as to achieve the purpose of current sharing; each phase of the cascaded H-bridge frequency converter is formed by connecting N power units of an H-bridge structure in series, each power unit is independently controlled, DC bus voltages of all the power units are sampled in each control period, and dynamic weight adjustment is carried out according to the power units with large deviation so as to achieve the purpose of voltage sharing.

The invention relates to the technical field of carrier synchronization, in particular to a carrier synchronization method and a synchronization control device based on an FPGA (Field Programmable Gate Array), and the method comprises the three stages of phase preprocessing, phase verification and dynamic synchronization regulation: the FPGA captures Sync0 signals generated by an EtherCAT distributed clock, the Sync0 triggering moment is calibrated to an effective regulation interval in the preprocessing stage, and the Sync0 signals are subjected to dynamic synchronization regulation in the dynamic synchronization regulation stage; phase stability is confirmed through continuous ten Sync0 trigger detection in the verification stage, and phase synchronization and frequency compensation are executed based on the Sync0 in the dynamic adjustment stage; the device comprises an MCU (Microprogrammed Control Unit) and an FPGA (Field Programmable Gate Array) which are integrated with the ESC and form a bidirectional link transmission signal through an IO (Input / Output According to the invention, the EtherCAT distributed clock compensation technology and the FPGA nanosecond time sequence control capability are combined, the Sync0 synchronization precision can reach up to 20ns, the synchronization stability and anti-interference performance are improved through a three-level adjustment mechanism, the dependence of a single host is eliminated, the multi-node cooperation is supported, the problems of low precision, poor stability and limited expandability of a traditional master-slave synchronization method are solved, and the synchronization precision of the Sync0 is improved. The method is suitable for scenes of multi-axis synchronous control, distributed parallel inversion and the like.

The embodiment of the invention provides a distributed dual-inverter carrier synchronization method and system based on common-mode voltage feedback, and belongs to the technical field of inverter control. According to the scheme, a total common-mode voltage signal of the distributed double inverters is obtained; performing signal preprocessing on the total common-mode voltage signal to obtain a preprocessed signal containing carrier phase difference information; performing proportional processing according to the pre-processing signal to obtain a frequency correction amount; frequency compensation is carried out on a target inverter according to the frequency correction amount, a carrier frequency control signal is obtained, and the target inverter is a sub-inverter in the distributed double inverters; and carrying out carrier synchronization control on the target inverter according to the carrier frequency control signal. According to the invention, carrier synchronization of the distributed double inverters can be realized without communication, and common-mode voltage is eliminated.

The application discloses a kind of multi-machine parallel adaptive carrier synchronization method, system, equipment and storage medium, wherein the method comprises: through the ECAP module of DSP, the synchronization signal sent by host computer is captured, and the time difference Δt (n) of the time from the time when the ECAP module is captured to the time when the synchronization signal enters interrupt is calculated;The time difference Δt (n) and the last time PWM period adjustment step S (n-1) are fuzzy operated to obtain the current time PWM period adjustment step s (n);According to the current time PWM period adjustment step s (n), the PWM period of slave machine is adjusted to realize carrier synchronization.The application not only has high speed, high precision, but also increases the stability when multi-machine parallel, has higher market promotion value.

The application relates to a demodulation device for continuous multicarrier signals aiming at efficient transmission in the field of digital signal processing, which comprises a digital shunt module, a multi-path matching filter module, a multi-path timing synchronization module, a multi-path frame header capture module, a multi-path descrambling and despreading module, a multi-path carrier synchronization module, a multi-path demapping and decoding and packet assembling module and a decoding module. The application can realize efficient transmission of FPGA, can extend to support demodulation of multiple modulation and spread spectrum coding modes and multiple rate continuous signals, can support 64-way or even more continuous multicarrier demodulation, and the performance loss of baseband demodulation is less than 0.5 dB. The application is suitable for processing more users and larger capacity high-throughput system gateway stations and satellite transponder load demodulators.

The invention discloses a signal denoising and carrier synchronization method and device of a continuous wave mud pulse system, and belongs to the field of measurement while drilling in petroleum drilling. The method comprises the following steps: S1, preprocessing a collected mud pulse signal; s2, adjusting a noise covariance matrix of an adaptive Kalman filter in real time based on an expectation maximization algorithm, and reconstructing and filtering harmonic waves of each order of pump noise through a pump noise linear time-invariant space state model by using the adjusted adaptive Kalman filter; s3, filtering random noise by adopting a wavelet threshold denoising method; s4, performing frame synchronization on the denoised signal by using the m sequence; s5, demodulating the mud pulse signal by adopting a BPSK (Binary Phase Shift Keying) orthogonal demodulation technology; and S6, adjusting a noise covariance matrix of the unscented Kalman filter in real time based on an expectation maximization algorithm, and estimating and compensating the phase offset by using the adjusted unscented Kalman filter through the nonlinear state space model of the phase offset and the frequency offset.

The invention discloses a multi-modulation system carrier synchronization integrated judging and locking device for satellite-to-ground data transmission, and belongs to the field of satellite-to-ground data transmission. The device comprises an AD conversion module, a digital down-conversion module, a low-pass filtering module, a half-band filter bank module, a digital resampling module, a matched filtering module, a carrier phase tracking module, a carrier phase error calculation module, a timing error calculation module and a carrier synchronization judging and locking module. According to the invention, the carrier synchronization integrated locking judgment function of multiple modulation systems in a satellite-ground high-speed data transmission CCM transmission mode and a VCM transmission mode is realized, the adaptability of the device is improved, and the device is convenient to realize and popularize.

The invention discloses a wired parallel operation high-frequency synchronization method for an inverter, which is used for realizing power frequency synchronization and high-frequency carrier synchronization through a group of power frequency synchronization signals and comprises the following steps of: configuring a circuit; after the plurality of inverters are connected in parallel in a master-slave working mode, the output ends of the inverters are connected to load equipment; the host device sends a power frequency synchronization signal to the slave device, and the slave device detects the power frequency synchronization signal; calculating the phase difference of the high-frequency carrier signals between the slave equipment and the host equipment; and the slave equipment adjusts own high-frequency carrier frequency according to the phase difference. Compared with a traditional scheme, the use number of IO ports is reduced, the circuit structure is simplified, and the requirement for circuit components is lowered. Meanwhile, synchronous signals are accurately captured and synchronous information is obtained through the capturing function of the main control unit, slave carrier wave frequency is adjusted through a software algorithm to achieve parallel operation, the influence of hardware circuit signal delay on parallel operation is greatly weakened, universality is higher, reliability is higher, and the parallel operation effect is better.

The invention discloses a high-complexity GNSS (Global Navigation Satellite System) induced deception detection method, device and equipment and a storage medium, and the method comprises the steps: carrying out the tracking monitoring of a plurality of same-frequency and same-phase GNSS satellite signals, constructing an AOSTL primary detection quantity based on the absolute value of an output result of a tracking loop of a receiver, the output result of the tracking loop comprises the output result of each correlator of an in-phase branch and an orthogonal branch, performing sliding variance processing on the AOSTL primary detection quantity, constructing an AOSTL-MV secondary detection quantity, determining a detection threshold based on Gaussian distribution characteristics, calculating a detection probability, and detecting whether a satellite signal has deception jamming based on the detection probability; the detection quantity is constructed based on the absolute value of the output result of each branch of the tracking loop, so that the detection quantity is not influenced by carrier synchronization, the detection sensitivity of the deception signal is improved, the deception signal with the same frequency and phase as a real signal can be accurately detected, and the concealment deception detection performance is improved.

The invention provides a converter control method and device, control equipment and a converter, and belongs to the technical field of power supplies. The converter comprises at least two inversion modules; a communication module is arranged between the midpoints of the DC buses of every two adjacent inversion modules, and the communication module comprises a first switch and a first buffer unit which are connected in parallel; the method comprises the following steps: acquiring a midpoint potential of a direct-current bus of each inversion module; for every two adjacent inversion modules, if the midpoint potentials of the DC buses of the two inversion modules are not equal, a first buffer unit between the two inversion modules is controlled to be switched on, and after the first buffer unit is switched on, a first switch between the two inversion modules is controlled to be switched on. According to the method, zero-sequence circulating current between the inversion modules can be avoided, carrier synchronization control in advance in a software control method and strict synchronization of a control process are not needed, and the control process is relatively simple.

The present disclosure belongs to the technical field of physical carrier synchronization, and relates to a trajectory prediction method and device, a storage medium and an electronic device. The method comprises the following steps: receiving first carrier movement data corresponding to a game carrier sent by a server, and determining second carrier movement data possessed by the game carrier at a current time; the first carrier movement data comprises a data sending time; if the current time is greater than the data sending time, the first carrier movement data and the second carrier movement data are calculated respectively, and a first carrier position corresponding to a first target time and a second carrier position corresponding to the current time are obtained; the first target time is different from the current time by a time interval; and the first carrier position and the second carrier position are mixedly calculated to predict a carrier position of the game carrier at the first target time. In the present disclosure, the accuracy of the predicted carrier position is increased.

The invention relates to the technical field of energy storage control, and discloses a centralized energy storage converter parallel application circulating current suppression method and system, and the method comprises the steps: a power synchronization strategy: building communication connection among a plurality of parallel energy storage converters, screening the operable energy storage converters based on a power direction and a power execution value, and carrying out the power synchronization strategy; stopping the other energy storage converters; wherein the operable energy storage converter adjusts self power output according to a preset power reference; according to a carrier synchronization strategy, one energy storage converter is designated as a host, the rest energy storage converters capable of operating serve as slaves, and the host keeps the PWM carrier phase fixed; the slave machine extracts common-mode circulating current parameters, the common-mode circulating current is in a stable state by adjusting the PWM carrier phase of the slave machine, and if the common-mode circulating current exceeds a safety range, abnormal early warning is given out. According to the invention, carrier synchronization and power synchronization of each energy storage converter can be ensured, so that common-mode voltage is reduced, and suppression of common-mode circulating current is realized.

The application relates to the field of parallel inverters and discloses a parallel inverter system and a synchronization method thereof. The synchronization method of the parallel inverter system comprises the following steps: a main inverter generates a synchronization signal and outputs the synchronization signal to a synchronization signal bus through a synchronization signal output port, wherein the synchronization signal is a PWM signal, and the synchronization signal cycle value is a preset output voltage cycle value; a slave inverter receives the synchronization signal from the synchronization signal bus through a synchronization signal receiving port, calculates an output voltage cycle reference according to a first preset jump edge of the synchronization signal, performs output voltage phase synchronization, and performs carrier synchronization according to a second preset jump edge of the synchronization signal. Thus, only a single synchronization signal line is used, the output voltage frequency, the phase synchronization and the carrier synchronization among multiple inverters can be realized, the interconnection wiring among the inverters can be simplified, the output voltage frequency, the phase synchronization and the carrier synchronization are time-multiplexed with the same synchronization signal, and time sequence conflicts can be avoided.

The application provides a motor working condition simulation device and method integrated with port switch voltage online monitoring. Through the integrated port switch voltage signal online monitoring circuit and the voltage sensor, the average value of the port voltage of the electric drive inverter, the pulse width modulation mode of the electric drive inverter, the carrier signal and the modulation signal and other key information can be extracted without relying on the voltage low-pass filter, the electric drive inverter carrier signal, the modulation signal or other voltage sampling devices. The motor working condition simulation device and method integrated with port switch voltage online monitoring provided by the application realize the carrier synchronization of the simulation inverter and the electric drive inverter to reduce the current ripple without the need of the electric drive inverter to provide the synchronization signal; and the extraction of the average value of the port voltage is realized without relying on the voltage sampling filter, so that the dynamic performance of the motor working condition simulation device is improved.