35 results about "Total frequency" patented technology

The invention, which belongs to the technical field of electromagnetic signal monitoring, relates to a rapid judgment method for a spatial spill electromagnetic signal, and the method specifically comprises the following steps: S1, receiving a spill electromagnetic signal in a space; s2, dividing the monitoring total frequency band into a plurality of sub-frequency bands with the same width, rapidly analyzing the obtained electromagnetic signal frequency spectrum in real time based on multi-scale spectrum entropy analysis, and positioning the frequency band where the characteristic signal is located; and S3, converting the frequency spectrum of the frequency band where the characteristic signal is located into a time domain signal, and simultaneously displaying a spectrogram and a time domain waveform. Through spectrum segmentation, multi-scale spectrum entropy analysis, adaptive threshold judgment and frequency domain-time domain combined display, the problems of poor real-time performance, weak anti-noise capability and single dimension in the prior art are solved.

The invention relates to the technical field of output sharing control, in particular to a multi-path power regulator control method and system, and the method comprises the following steps: collecting real-time data to establish a data queue, calculating a mean value and a standard deviation to generate a dynamic operation baseline, collecting the real-time data to establish the queue, calculating the mean value and the standard deviation to generate a dynamic baseline, the method comprises the following steps: calculating an adaptive over-current and open-phase alarm threshold based on a baseline, adding an external control quantity to obtain a total power demand, adjusting the number of cycles according to the stability of a load, reducing the number of active whole waves in proportion when the number exceeds the limit, and stopping a thyristor triggering instruction when the current or voltage abnormally and continuously reaches a preset count. According to the method, the self-adaptive threshold is calculated by establishing the dynamic operation base line in combination with the fluctuation amplitude and the sensitivity factor, current and voltage abnormity is specifically recognized, the total cycle number and the active whole wave number are adjusted in combination with the external power requirement and the load stability, single trigger angle control dependence is avoided, and power distribution balance and electric energy supply stability are achieved; and the equipment damage risk is reduced.

The application discloses a power distribution network communication fault type identification method and device, electronic equipment and storage medium, the method comprises the following steps: obtaining the voltage mode time-frequency matrix before and after the occurrence of the power distribution network communication fault, extracting the voltage fundamental wave amplitude, the voltage main harmonic amplitude and the voltage main harmonic amplitude frequency before and after the occurrence of the communication fault; obtaining the current mode time-frequency matrix before and after the occurrence of the power distribution network communication fault, extracting the current direct current amplitude, the current main harmonic amplitude, the current main harmonic amplitude frequency and the current total frequency band amplitude before and after the occurrence of the communication fault; based on the above parameters, a criterion is constructed to determine whether the power distribution network communication fault type is a lightning flashover communication fault or an insulator pollution flashover communication fault. Through the implementation of the application, the lightning flashover communication fault and the insulator pollution flashover communication fault in the power distribution network can be effectively identified, thereby significantly improving the operation reliability of the power distribution network and ensuring the safe and stable operation of the power system.

The invention discloses a method and a system for constructing a collision-zone-free frequency hopping sequence set in a '1 + M' form, and mainly solves the problems that in the prior art, frequency point collision is generated when time delay deviation is large, and new collision is introduced in a secondary mapping or expansion process. The implementation scheme of the method comprises the following steps: generating two frequency hopping sequence set sums with different collision-free regions by adopting a collision-free region construction method; combining the two sequence sets to obtain 1 + M frequency hopping sequences; segmenting 1 + M frequency hopping sequences according to a set length to obtain sequence segments of the first sequence; setting random numbers which are uniformly distributed between 0 and 1, and constructing a zeroth dynamic frequency slot set and a first dynamic frequency slot set by utilizing the sum of the frequency slot sets, the size of the total frequency slot set and the sum of frequency slot elements in the total frequency slot set; and performing frequency slot mapping by using the sum sequence segment to obtain a collision-zone-free frequency hopping sequence set consisting of 1 + M frequency hopping sequences. According to the method, effective expansion of the collision-free area can be realized while the consistency of the sequence structure is kept, and the method can be used for orthogonal frequency hopping networking when the relative time delay difference between users is relatively large.

Method for exciting one or more, preferably piezoelectric, transducers (7), which transducers (7) are designed to generate sound waves and have operating frequencies which define a converter frequency range, in which a generator (9) which has an electrical connection (8) to the converters (7) and a frequency sweep function for generating an electrical excitation signal with a variable excitation frequency (1) generates an electrical excitation signal for the converters (7), which excitation signal is supplied to the converters (7), wherein the generator (9) with an adjustable sweep rate performs a total number of frequency sweeps in a frequency sweep range between a minimum frequency (f min ) and a maximum frequency (f max ) carries out, within which frequency sweep range a target frequency (f Ziel ) is defined, characterized by the fact that the minimum frequency (f min ), the maximum frequency (f max ) and the target frequency (f Ziel ) are chosen such that a first frequency difference (Δf1) exists between the minimum frequency (f min ) and the target frequency (f Ziel ) during a first number of frequency sweeps from the total number of frequency sweeps, preferably during substantially all frequency sweeps, in magnitude from a second frequency difference (Δf2) between the maximum frequency (f max ) and the target frequency (f Ziel ) differs, and where the minimum frequency (f min ) and / or the maximum frequency (f max ) and / or the target frequency (f Ziel) is modified after at least one frequency sweep such that an arithmetic mean of the first frequency differences (Δf1) and an arithmetic mean of the second frequency differences (Δf2) formed over all frequency sweeps are essentially equal in magnitude.

The application relates to the technical field of AD sampling, and discloses a fast high-precision AD sampling method based on statistics, an AD sampling device and a storage medium, the method comprising the following steps: acquiring sampling data; counting N AD sampling values with the highest sampling frequency ranking in the sampling data; combining X AD sampling values adjacent to each AD sampling value in the N AD sampling values into a group of data to form a plurality of groups of data; accumulating effective sampling frequencies in the plurality of groups of data to obtain a plurality of total frequencies; and taking an AD sampling value located at a middle position in a group with the maximum frequency among the plurality of total frequencies as a sampling result. The AD sampling value obtained by the method is relatively stable, the system stability can be ensured by using the calculation mode in medium-scale sampling, the calculation amount is small, the anti-interference capability is good, and the output result is more accurate.

The application provides a non-destructive size measurement method for underground targets by combining frequency coding and half-integer phase control, and belongs to the field of non-destructive size measurement of underground targets. The method solves the problem that the prior art cannot effectively overcome the near distance blind area and suppress the frequency domain sidelobe. The method comprises the following steps: constructing an equal-interval frequency grid; generating a transmission frequency sequence by using a step parameter coprime with the total frequency point number for coding sorting; defining the effective transmission duration of each frequency point time slot, so that the near distance blind area range is determined by meeting the half-integer period condition; in each frequency point time slot, a linear sweep signal is generated, and the cumulative phase of the signal at the end of the time slot is controlled to meet the half-integer circle constraint; the signal is transmitted in sequence, and the echo signal is received synchronously; the complex frequency response of each frequency point is extracted, and after frequency domain coherent synthesis, the phase information is differentially approximated to obtain the group time delay; and the target geometric size is calculated according to the medium propagation speed and the group time delay. The method is used in the field of pipe network detection.

The invention discloses a method for automatically measuring impedance of a power electronic converter based on a real-time simulation platform, which comprises the following steps of: adding a disturbance injection module and a data acquisition module into a simulation model, and calculating load flow or performing time domain simulation to obtain a steady-state working point; parameters needing to be measured are determined in the disturbance injection module; according to the measurement starting time, the wave recording starting time, the real-time simulation step length, the sampling factor, the storage file size and the storage file of a data acquisition module in the real-time simulation platform are determined, and according to the measurement starting time, the frequency disturbance duration of each time, the disturbance interval waiting time and the total frequency number of the frequency sequence, the real-time simulation total duration is determined; injecting disturbance, and acquiring a voltage and current data set of the tested port; and calculating the impedance value of the total frequency number of the frequency sequence, and generating a full-band impedance characteristic curve. According to the measurement method disclosed by the invention, the impedance scanning efficiency is improved, and the impedance of the new energy equipment is quickly and accurately acquired.

The invention is a kind of wind farm droop control frequency modulation method with pitch angle protection function, wind farm control center receives the load shedding mode and adjustable power of wind turbine; the wind turbine is divided into two groups by whether to use pitch angle load shedding, and the total frequency modulation power of the wind farm and the two groups is calculated according to the calculation; the control center determines the total droop coefficient of the wind farm according to the total adjustable power of the wind farm; the total droop coefficient of the two groups is determined according to the adjustable power of the two groups, and the relationship between the frequency modulation participation rate ρ and σ and the maximum adjustable frequency modulation power of G1, G2 and the maximum adjustable frequency modulation power of the wind farm is calculated; the droop coefficient of the wind turbine is determined according to the adjustable power of the wind turbine, and it is sent to each wind turbine; finally, the wind turbine adjusts the droop coefficient in real time according to the received information, and completes the frequency modulation work. The invention preferentially makes the wind turbine without pitch angle load shedding to perform frequency modulation, reduces the pitch angle action amplitude and frequency of the wind turbine with pitch angle load shedding, protects the mechanical device of the wind turbine, and prolongs the service life of the wind turbine.

This invention proposes an adaptive collaborative frequency regulation method and system for ship-to-shore power systems based on panoramic perception, relating to the field of collaborative control technology between ship-to-shore power and power systems. The key technical points of this invention include: collecting multi-source heterogeneous operating status data from the ship, port, and power grid; constructing a fused state variable set after preprocessing the multi-source heterogeneous operating status data; determining whether frequency regulation is needed based on the fused state variables; if frequency regulation is needed, calculating the total frequency regulation demand of the ship-to-shore power system based on the fused state variable set; establishing an objective function with the optimization goal of minimizing frequency deviation and power fluctuation, solving it under constraints, and optimally allocating the total frequency regulation demand to the ship, port, and power grid layers. This invention significantly improves the observability of the shore power system status, increases response speed, alleviates the pressure on single frequency regulation resources, and improves the stability of the frequency recovery process. This invention can be integrated and deployed based on existing monitoring devices, energy storage converters, and shore power control platforms, facilitating implementation in port areas.

The invention discloses a transmitting and receiving end multi-resource power distribution method for optimizing a frequency modulation power distribution coefficient, and belongs to the technical field of power system frequency control. The method comprises the following steps: acquiring various frequency modulation resource parameters, and establishing a transmitting-receiving end power system frequency response mathematical model; constructing a target function and a frequency security constraint condition which take the minimum total frequency modulation cost as a target; establishing a particle swarm optimization model, and taking a target function as a fitness function; iteratively optimizing a frequency modulation distribution coefficient in combination with a particle swarm algorithm and transient simulation; and generating a distribution instruction according to the optimal coefficient. According to the method, the adjustable frequency modulation distribution coefficient is introduced, and the transmitting and receiving end coupling characteristics, the multi-resource cost difference and the transient safety index are considered, so that multi-resource cooperative frequency modulation is realized. An application result shows that the frequency modulation cost of the system is reduced by 2.61%, the frequency stability is remarkably improved, a new energy high-proportion grid-connected scene is adapted, and the defects of a traditional distribution mode are overcome.

The invention discloses a cooperative control method and system for a new energy unit and a station to participate in primary frequency modulation. Establishing a primary frequency modulation model of the new energy power supply based on the unit model of the new energy power supply, a frequency controller link and a configured load shedding operation algorithm; according to the output power variation of the new energy power supply, the output power variation of the traditional power supply and the load demand, calculating the frequency deviation of the power system; under the load shedding operation condition, the effective wind speed, the rotor kinetic energy reserve and the power reserve index of each unit are collected in real time, the standardization score of each unit is calculated, an entropy weight method and a variable coefficient method are combined for weighting, and the frequency modulation potential comprehensive score of each unit is calculated; and determining the total frequency modulation power demand of the new energy station based on the power grid frequency deviation, and calculating the frequency modulation responsibility proportion and responsibility power of each unit in real time through a dynamic weight distribution algorithm in combination with the frequency modulation potential comprehensive score.

Provided are a method and device for transmitting information, the method for transmitting information comprising: a first terminal device determining a first resource for transmitting information, so that a total frequency range corresponding to the first resource and a first control resource set on a frequency domain is less than or equal to a maximum channel bandwidth supported by the first terminal device; the first terminal device transmits information in the first resource, thereby solving the problem of frequent switching of the working frequency in the network access process of the communication device, effectively saving the power consumption of the communication device, and improving the flexibility of information transmission.

The invention provides a satellite multi-beam resource scheduling method based on reserved groups, which comprises the following steps of: dividing available total frequency carrier resources of a satellite communication system into reserved frequency resource groups and flexible frequency resource groups, and allocating non-overlapped frequency bands for the divided groups to realize frequency isolation; dynamically determining the number of channels which should be occupied by the reserved frequency resource group according to the historical traffic data of each beam; for a received new user access request, allocating resources of the used beam in the reserved frequency resource group; and if the reserved frequency resource group cannot meet all the access requests, transferring the remaining requests which cannot meet all the access requests to the flexible frequency resource group for resource allocation. The invention further provides a satellite multi-beam resource scheduling system based on the reserved grouping. Therefore, the resource scheduling complexity can be remarkably reduced, the system resource utilization rate and the operation stability are improved, and flexible and efficient on-demand allocation is realized.

This application provides a communication method and related apparatus. The method includes: generating a trigger frame; the trigger frame includes user information fields corresponding to one or more users, the one or more users including a first user using joint source channel coding; the first user corresponds to multiple user information fields, one user information field corresponding to the first user is used to indicate the first user's layer frequency domain resources in one source layer; or, the first user corresponds to one user information field, the one user information field corresponding to the first user is used to indicate the first user's total frequency domain resources in all source layers; sending the trigger frame to receive trigger-based physical layer protocol data units from the first user, the trigger-based physical layer protocol data units including jointly source channel coded data located in the first user's layer frequency domain resources, thereby realizing joint source channel coded transmission based on the trigger frame.

There are provided measures for efficient utilization of spectrum extension resources. Such measures exemplarily comprise: generating an uplink signal, where the uplink signal is a spectrally spread signal corresponding to a total frequency band allocation comprising an in-band portion and at least one out-of-band portion, where the at least one out-of-band portion corresponds to the spectral spread; and transmitting the uplink signal, and in relation to the generation, such measures exemplarily comprise: dividing a data stream to be transmitted into a first data substream and a second data substream; modulating a symbol of the uplink signal based on the first data substream; arranging the symbols in the in-band portion; copying the symbols arranged in at least one predetermined sub-portion of the in-band portion to the at least one out-of-band portion; determining a first state subcarrier of the total band allocation and a second state subcarrier of the total band allocation based on the second data substream, wherein a first subset of the second state subcarriers is located in the at least one out-of-band portion; and modifying the symbols arranged on the second state subcarrier.

The invention discloses a frequency modulation equipment capability evaluation method and device based on an energy visual angle. The method comprises the following steps: acquiring equipment parameters, network parameters and preset fault information of a system, and initializing equivalent speed regulator model parameters by aggregating the equipment parameters; based on the equivalent speed regulator model parameters, the network parameters and preset fault information, establishing a vibration mechanical model of the power system; solving the vibration mechanical model according to a modal analysis method, and obtaining a common-mode component and an oscillation component of the frequency variation of the power system; determining the frequency variation of each unit in the power system according to the common-mode component and the oscillation component; according to the frequency variation and the equivalent speed regulator model parameters, calculating the total unit frequency modulation energy accumulated at the maximum frequency deviation moment of each unit; and calculating the frequency modulation capability contribution degree of each unit based on the total frequency modulation energy of each unit, and outputting a frequency modulation capability evaluation conclusion of each unit according to the frequency modulation capability contribution degree of each unit.

The invention discloses a time-frequency synchronization method and system for orthogonal frequency division multiplexing transmission of an unmanned aerial vehicle, and belongs to the field of communication. The method comprises the steps of obtaining a baseband receiving signal transmitted by an unmanned aerial vehicle end; the baseband receiving signal is generated according to a superposed signal generated by a pseudo-random noise sequence and a preset power distribution factor; generating a synchronization function according to the baseband receiving signal and a preset local time domain training sequence; performing coarse estimation on the phase difference between the cyclic prefix and the symbol main body according to the symbol starting point at the moment when the peak value of the synchronization function exceeds the preset threshold value to obtain coarse estimation frequency offset, performing coarse compensation correction on the baseband receiving signal, and performing fine estimation on the subcarrier phase rotation amount by the baseband receiving signal after coarse compensation to obtain fine estimation frequency offset; and performing frequency offset correction on the baseband receiving signal according to the total frequency offset obtained by adding the coarse estimation frequency offset and the fine estimation frequency offset. According to the invention, the problem that broadband offset coverage and high synchronization precision cannot be satisfied simultaneously in the prior art is solved.

The application discloses a kind of impedance automation measurement methods of power electronic converter based on real-time simulation platform, including in simulation model, disturbance injection module, data acquisition module, computing flow or time-domain simulation obtains steady state operating point;In disturbance injection module, the parameter that needs to be measured is determined;According to the starting time of measurement, the starting time of the recording wave of data acquisition module in real-time simulation platform, real-time simulation step, sampling factor, storage file size and storage file are determined, and according to the starting time of measurement, the duration of each frequency disturbance, disturbance interval waiting time, the total frequency number of frequency sequence, the total duration of real-time simulation is determined;Injection disturbance, and the voltage and current data set of measured port are obtained;The total frequency number of frequency sequence is calculated impedance value, and full-band impedance characteristic curve is generated.According to the measurement method disclosed in the application, the impedance scanning efficiency is improved, and the new energy equipment impedance is quickly and accurately obtained.

The invention relates to a primary frequency modulation method and system for fusion of a hydropower station and an energy storage power plant, and aims to overcome the defects of slow response and limited regulation capacity during independent frequency modulation of the hydropower station. The power grid frequency is collected in real time, a total frequency modulation output instruction is generated, real-time operation parameters of a hydropower station and an energy storage power plant are obtained, the total instruction is dynamically decomposed into a hydropower station sub-instruction and an energy storage sub-instruction based on a preset collaborative distribution strategy, output increasing and decreasing requirements are distinguished, and the energy storage charge state is combined. Energy storage is preferentially utilized to realize rapid initial response, then the hydropower station provides continuous support, meanwhile, the output proportion is dynamically adjusted according to the operation states of the two parties, and an optimization cooperation strategy is fed back by continuously monitoring the actual frequency modulation performance and comparing the actual frequency modulation performance with an assessment index. According to the invention, advantage complementation of two kinds of resources is realized, and the response speed, the capacity guarantee capability and the adaptability to power grid examination requirements of combined frequency modulation are improved.

The application discloses a real-time EQ curve forming method based on a mobile terminal, which comprises the following steps: dividing frequency bands into a first frequency band, a second frequency band and a third frequency band in sequence according to the frequency from small to large, and determining the first frequency band, the second frequency band and the third frequency band as the initial frequency point quantity of the EQ curve horizontal coordinate respectively; determining the width of the EQ curve according to the resolution of the mobile terminal, and screening the frequency points from the third frequency point quantity again according to the width to obtain the final third frequency point quantity; taking the frequency point as the horizontal coordinate, the audio amplitude corresponding to the frequency point as the vertical coordinate, and adopting a polygon method to draw the EQ curve according to the total frequency point quantity of the first frequency point quantity, the second frequency point quantity and the final third frequency point quantity, so as to obtain the EQ curve. The application can quickly generate the EQ curve, and can more quickly and smoothly display the EQ curve due to smaller calculation quantity, and the formed EQ curve is more coherent and smooth.

The invention provides a flight data jump detection method and device, equipment and a storage medium, relates to the technical field of aviation data detection, and can effectively improve the flight data jump detection accuracy. The method comprises the following steps: acquiring flight data, and preprocessing the flight data; short-time Fourier transform is carried out on the preprocessed flight data, frequency domain distribution information of each time window in a plurality of time windows is determined, and the frequency domain distribution information is used for indicating frequency domain signal energy distribution conditions in the time windows; determining a high-frequency frequency domain signal energy ratio of each time window based on the frequency domain distribution information of each time window; the high-frequency frequency domain signal energy ratio is used for indicating the ratio of the sum of squares of the frequency domain signal energy to the total frequency domain signal energy under the condition that the frequency is higher than a preset frequency threshold value; and under the condition that the high-frequency frequency domain signal energy ratio of at least one time window is greater than a preset energy ratio threshold, determining that the flight data has a jump behavior.

The application relates to the technical field of semiconductor device testing, and discloses a wide-frequency-range semiconductor device low-frequency noise precise measurement method, which comprises the following steps: bias voltage is applied to a device to be tested, and current is collected; a thermal equilibrium state is determined by calculating a current change rate; when the change rate meets a stability threshold, measurement is triggered, and thermal drift interference is eliminated. In response to a trigger signal, a load switching unit is controlled to access an impedance-matched equivalent resistance network; under the condition of maintaining device direct-current power supply and junction temperature thermal equilibrium, system background noise spectrum is collected in situ. Then, a total frequency band is divided into multiple sub-frequency bands, a preamplifier gain and a sampling rate are adjusted in cooperation, original data are acquired, and a full-frequency-band total measurement noise spectrum is synthesized. Finally, background noise spectrum is subtracted from the total spectrum to obtain a net noise power spectral density, and defect parameters are extracted by using a physical model. The application effectively expands the dynamic range of high-frequency measurement, and improves the detection precision and physical characterization capability of weak defect signals.

The invention discloses a frequency modulation control method and device for a virtual power plant, a storage medium and electronic equipment. The method comprises the following steps: determining the total frequency modulation power of a target virtual power plant at a target moment, and determining at least one first device to which the frequency modulation power is to be allocated; determining a second device from the at least one first device, and obtaining a transmission loss coefficient matched with the second device; determining a frequency modulation priority coefficient corresponding to the second equipment based on the transmission loss coefficient matched with the second equipment; and distributing the frequency modulation total power to at least one first device based on the frequency modulation priority coefficient corresponding to each first device. The technical problem that the reliability of external frequency modulation response of the virtual power plant is low is solved.

A method comprises receiving, by a first node from a second node, a request for a resource status of a cell of the first node. The cell operates in subband full duplex (SBFD). The method comprises determining a ratio or percentage of SBFD frequency resources used in the cell with respect to total frequency resources of the cell and transmitting, by the first node to the second node, a response comprising the ratio or percentage of the SBFD frequency resources used in the cell.

The present application relates to the technical field of output sharing control, in particular to a kind of multi-path power amplifier control method and system, comprising the following steps: real-time data is collected to establish data queue, mean and standard deviation are calculated to generate dynamic operation baseline, real-time data is collected to establish queue, mean and standard deviation are calculated to generate dynamic baseline, adaptive overcurrent and open-phase alarm threshold are calculated based on baseline, total power demand is obtained by summing external control quantity, according to load stability adjustment frequency, when exceeding limit, active whole wave number is adjusted by proportion to lower, when current or voltage abnormally reaches the designed number continuously, thyristor trigger instruction is stopped.The present application, by establishing dynamic operation baseline, combined with fluctuation amplitude and sensitivity factor to calculate adaptive threshold, current and voltage abnormalities are identified specifically, combined with external power demand and load stability to adjust total frequency and active whole wave number, avoid single trigger angle control dependence, realize power distribution balance and power supply stability, reduce equipment damage risk.

This invention relates to a noise control method, medium, and electrical equipment for a fan system. It calculates the noise difference between the average noise value and the total noise value within one-third octave bands of the noise frequency range at the motor's operating position. When this noise difference exceeds a preset noise difference threshold, and the current value of the area of ​​each sub-inlet area at the volute's rear cover is greater than or equal to the initial value of the corresponding sub-inlet area area, the absolute value of the noise difference between the average total noise value within one-third octave bands of the noise frequency range and the obtained average noise value is calculated. When this absolute value exceeds a preset threshold, all noise frequency bands exceeding the average total noise value within the sub-inlet area are taken as the total frequency range of the sensitive frequency band. Noise reduction is then applied to each sub-inlet area sequentially within the preset total frequency range of the sensitive frequency band, thereby enabling real-time detection of noise in the inlet area and targeted noise reduction.

The invention provides a cluster CPU cooperative frequency regulation method and system, computer equipment and a medium. The cluster CPU cooperative frequency regulation method of one embodiment comprises the following steps: generating a global total frequency modulation parameter through a trained time sequence regression model; synchronizing the global total frequency modulation parameter to all nodes of a whole cluster by adopting a seed relay diffusion mode based on an adjacent topological relation between the nodes, and updating an adjacent frequency modulation table locally maintained by each node; based on the adjacent frequency modulation table after all nodes of the whole cluster are synchronized, completing distributed optimal frequency modulation representative node election, executing inter-node distribution of global total frequency modulation parameters through the selected representative nodes, and generating target operation frequencies of all the nodes; and each node executes CPU frequency adjustment operation based on the allocated target operation frequency. According to the embodiment of the invention, the cooperative frequency of a plurality of nodes can be realized before the load tide comes.

The invention relates to a multi-connected air conditioner and a control method thereof, and belongs to the technical field of air conditioners. The actual running total frequency and the total upper limit frequency of the running compressors are obtained in real time, and the preset target total frequency of the outdoor unit is obtained; if the actual total operation frequency is not equal to the target total frequency, determining a load coefficient according to the ratio of the target total frequency to the total upper limit frequency; the operation number of outdoor units in the outdoor units is determined according to preset unit configuration logic; re-determining the load coefficient; and according to the re-determined load coefficient and the preset frequency configuration logic, the target frequency of each running compressor is configured, and each running compressor in the multi-connected air conditioner is controlled to run according to the corresponding target frequency, so that the output capacity of the system is accurately matched with the dynamic change requirement. And meanwhile, it is ensured that all the compressors operate in an efficient working interval, and therefore continuous optimization of the overall energy efficiency of the system is achieved on the premise that the comfort requirement is met.