232 results about "Harmonic mitigation" patented technology

The invention discloses a DC voltage divider parameter anomaly detection method based on harmonic characteristics, and the method comprises the steps: deploying an isolation type voltage sensor at a bus of a DC power transmission system, carrying out the voltage sampling through combining with an ADC, carrying out the data buffering and preprocessing, extracting a fundamental wave component and a target harmonic component through the fast Fourier transform, and calculating the harmonic distortion rate. And constructing a low-voltage arm capacitance and harmonic distortion rate model based on a voltage divider secondary circuit equivalent circuit and an energy distribution principle, and calibrating the low-voltage arm capacitance and harmonic distortion rate model. And designing a multi-objective optimization scheduling algorithm based on energy storage capacity and capacitance characteristics, and realizing dynamic power distribution and harmonic suppression of the system. And after abnormal triggering, the system automatically loads a capacitance compensation coefficient, adaptively adjusts algorithm parameters in combination with a measurement loop PI control link, reduces a harmonic amplification effect, and ensures that a measurement error is within an acceptable range. Harmonic monitoring precision and capacitance compensation optimization capability of the direct-current power transmission system are effectively improved, and stable operation of the system is guaranteed.

The invention relates to a rectification harmonic suppression control method for a double reverse star transformer. The method comprises the following steps: establishing a rectifier bridge arm phase characteristic parameter table in a control platform, and recording a theoretical conduction phase, winding attribution and waveform synchronization characteristics of a bridge arm; in the operation process of the rectification control unit, the output current of a transformer and the conduction state of a bridge arm are collected, and a rectification operation state data set is generated; and calculating bridge arm conduction phase deviation, and analyzing a corresponding harmonic component to obtain a mapping relation between a bridge arm state and harmonic distribution. And judging whether the current bridge arm configuration meets the phase coverage requirement of the target rectification pulse number or not according to the mapping result, and if not, selecting a standby bridge arm group with a preset phase difference and generating a switching instruction. And the rectification control unit responds to the instruction to lock the current bridge arm conduction path and release the target bridge arm group so as to realize bridge arm resource dynamic reconstruction and rectification performance optimization. Harmonic waves can be effectively suppressed, and the topology adaptability and the output quality of the rectification system are improved.

The invention provides a wide-voltage self-adaptive closed-loop vector swimming pool pump anti-interference method, and relates to the technical field of motor control and power electronics, and the method comprises the steps: collecting three-phase power supply voltage fluctuation characteristic parameters and motor operation state parameters in real time; performing amplitude compensation and phase synchronization correction on the voltage parameter based on the dynamic voltage compensation factor; a closed-loop vector anti-interference control model is constructed, and model parameters are adjusted in real time through a vector immunity coefficient; dynamically correcting control output by adopting a multivariable feedback regulation mechanism; executing an anti-interference instruction and synchronously updating PWM modulation parameters, and verifying a control effect in combination with hardware-in-the-loop simulation; and parameter self-learning optimization is realized through a genetic algorithm. The dynamic anti-interference capability under power grid voltage fluctuation and harmonic interference is improved, intelligent thermal management is realized through a temperature-voltage-current multi-dimensional coupling model, full-life-cycle self-adaptive optimization of the system is guaranteed, and the problems of compensation lag, insufficient harmonic suppression and poor long-term stability are effectively solved.

The invention discloses a micro-grid electric energy quality global optimization method, which comprises the steps of collecting real-time data, dividing the real-time data into a plurality of segments according to frequency, and calculating harmonic compensation capacity of each frequency band according to the real-time data; according to the harmonic compensation capacity obtained through calculation, priority distribution is carried out on the compensation sequence of the polluted nodes in the micro-grid; the virtual impedance and the injection damping resistance of the inverter are adjusted, and the harmonic current and the resonance phenomenon in the micro-grid are suppressed in different frequency bands; and according to the adjusted virtual impedance and damping resistance, updating a node admittance matrix, monitoring the compensation capacity of the inverter in real time, comparing real-time monitoring data with a threshold value, if the real-time monitoring data exceed the threshold value, correcting the inverter, otherwise, not changing. Through frequency-band-divided control, pertinence and effect of harmonic suppression are improved, frequency-band-divided suppression of micro-grid harmonic and high-frequency resonance is realized, residual capacity of an inverter and harmonic compensation requirements are dynamically matched, and safe and stable operation of a system is ensured.

The invention relates to a coordination method and device for harmonic suppression and reactive power compensation in a power distribution network. The method comprises the steps of obtaining power grid operation parameter information of a power distribution network; according to the power grid operation parameter information, the total current harmonic distortion rate, the power factor and each harmonic current information of the power distribution network are detected; detecting to-be-optimized parameters of the power distribution network according to the total current harmonic distortion rate, the power factor and the current information of each harmonic, the to-be-optimized parameters including at least one of each harmonic and reactive power; and according to the to-be-optimized parameters, suppressing each harmonic in the power distribution network and compensating reactive power in the power distribution network. The method can accurately perform cooperative control on harmonic suppression and reactive power compensation in the power distribution network.

The invention provides a permanent magnet frequency conversion double-sine modulation swimming pool pump energy-saving control method, and relates to the technical field of motor driving and control, and the method comprises the steps: building a double-sine carrier modulation model of a permanent magnet synchronous motor, and calculating a dynamic harmonic suppression factor and a double-sine modulation depth in real time; feedforward compensation is carried out on the inverter current based on the DHSIF, and a q-axis current reference value is generated by adopting double-closed-loop vector control; dynamically adjusting a carrier frequency range according to the DSMD, generating double sine carriers with a phase difference of pi / 3, and superposing the double sine carriers into a composite modulated wave; the modulation wave amplitude is corrected through a DHSIF, and fifth and seventh harmonics are eliminated in combination with an adaptive filtering algorithm; a carrier wave ratio is dynamically optimized to generate a PWM signal, and a transient compensation mechanism is triggered to correct a voltage instruction when a load suddenly changes; and an energy efficiency optimization database is constructed to call historical optimal parameters, and nonlinear mapping of DHSIF and motor characteristics is established through parameter self-tuning. According to the invention, cooperative control is realized through dynamic harmonic suppression, modulation depth optimization and intelligent thermal protection.

The invention relates to the technical field of power electronics and power transmission, and discloses a distributed multi-device differentiation and anti-interference cooperative harmonic suppression method, which comprises the steps of establishing a power generation data module, a power generation data analysis module, an execution module, an execution feedback module and an optimization upgrading module, the power generation data analysis module calculates data collected by the power generation data module and then establishes a harmonic impedance model in combination with the operation condition and historical data of the equipment, the execution module designs a specific harmonic suppression execution scheme of the harmonic impedance model, and the execution feedback module timely corrects the harmonic impedance model. And the model optimizing and upgrading module performs continuous optimizing and upgrading on the harmonic suppression method of the harmonic impedance model based on the power generation data accumulated for a long time, the feedback information of the execution feedback module and the actual operation experience of the execution module.

The invention discloses a method and device for preventing inverter harmonic waves from affecting operation of an electric energy meter, and the method comprises the following steps: a harmonic attenuation device is installed on an inverter line bus, and the harmonic attenuation device comprises an LC resonance circuit and a control circuit; dynamically matching the winding inductor and the safety capacitor based on the harmonic frequency spectrum characteristic of the inverter; a temperature sensing module is integrated on the body of each power resistor branch; the MCU microcontroller judges whether to trigger power resistor branch switching or not based on the temperature data and a preset temperature control strategy; after a relay switching action is triggered, a dynamic compensation strategy is generated to dynamically adjust inductance, capacitance and resistance topology so as to realize frequency stabilization and impedance matching; and executing closed-loop feedback optimization and health assessment based on the harmonic suppression effect after dynamic compensation and the system operation state. The invention has the following advantages and effects: the dynamic tracking of the LC resonant frequency on the harmonic dominant frequency is realized, and the thermal runaway problem of the harmonic energy absorption unit is synchronously solved.

The invention relates to the field of permanent magnet synchronous motor control, in particular to an RANF adaptive harmonic suppression method based on dustpan line optimization, which comprises the following steps: S1, establishing a d-q axis control model for a permanent magnet synchronous motor, listing voltage, current and electromagnetic torque equations, giving a harmonic current equation, and adopting an ANF adaptive notch extraction algorithm to obtain a harmonic current control model for the permanent magnet synchronous motor; obtaining estimated values of specific-order harmonic amplitude and phase, and generating harmonic compensation quantity from the estimated values by adopting a PI regulator so as to realize a steady-state indifference-free harmonic suppression effect; and S2, in order to solve the problem that the ANF adaptive harmonic suppression algorithm is difficult to follow the d-q axis current rapidly changing along with the direct current amount, an RANF adaptive harmonic suppression algorithm adopting an R regulator is proposed, the ANF following performance is greatly accelerated, and the practicability of the ANF is improved. When the motor load or the rotating speed changes, quick response can be achieved, system instability is avoided, the dynamic stability of the system is remarkably improved, and the application scene of ANF adaptive harmonic suppression in the permanent magnet synchronous motor is widened.

The invention discloses a vector reconstruction harmonic suppression method for a three-level inverter power supply permanent magnet synchronous motor, and relates to the technical field of motor harmonic and noise suppression. Calculating action time of three basic vectors, selecting the three basic vectors, adjusting an original vector synthesis sequence in a single carrier period into a vector reconstruction synthesis sequence, calculating three time nodes of a fifth-segment sequence and a sixth-segment sequence according to the original vector synthesis sequence, and calculating the time nodes of the fifth-segment sequence and the sixth-segment sequence; the action duration of the two basic vectors after adjustment is calculated according to the vector reconstruction synthesis sequence, the numerical value of a switching time node of a three-level inverter switching tube is updated according to the action duration, and the assigned value of a time register is calculated and updated in a circulating mode in the operation process of the permanent magnet synchronous motor system. And generating a PWM (Pulse Width Modulation) driving signal to control a three-level inverter switching tube to drive a motor. Improvement is carried out based on a traditional SVPWM technology, the high-frequency harmonic performance of the three-level inverter and the motor driving system can be remarkably improved, system cost and operation difficulty do not need to be increased, and the method is simple and easy to implement.

The invention provides a network construction type bidirectional low-harmonic energy storage converter based on virtual synchronous control and an intelligent load identification method thereof, and belongs to the field of power electronics. The converter comprises a power module and a control module, wherein the power module is used for bidirectional conversion and output of electric energy; the control module comprises a virtual synchronous control module and a harmonic suppression control module, and the virtual synchronous control module adopts a virtual synchronous generator technology to realize active / reactive power bidirectional adjustment during electric energy bidirectional conversion of the power module and network construction level voltage and frequency support during electric energy output; and the harmonic suppression module is provided with a parallel QPR controller group (comprising a first QPR controller, a second QPR controller and a third QPR controller) which are used for processing third-time, fifth-time and seventh-time characteristic harmonics respectively and suppressing the characteristic harmonics of the electric energy output side of the power module. According to the invention, the dual modules are arranged in the control module, so that the cooperation of a network construction function and low harmonic output is realized, and the electric energy quality and the system operation stability are effectively improved.

The invention relates to the technical field of power quality control, and discloses an inverter harmonic suppression cooperative control method, device and equipment and a storage medium, and the method comprises the steps: employing sliding window recursive discrete Fourier transform to decompose output voltage harmonic waves in real time; generating a reverse compensation voltage for the detected harmonic component; dynamically adjusting the sampling frequency according to the load current change rate; and superposing a high-frequency jitter signal in the modulated wave. Therefore, the problem of balance among harmonic suppression efficiency, dynamic response speed and system loss of a traditional inverter is solved. The dynamic switching frequency is adaptive, and various switching frequencies can be switched to replace traditional fixed frequency modulation based on the load current change rate; harmonic compensation is adopted, PR, namely SMC double closed-loop control is matched, low-harmonic high-quality waveform output is achieved, and meanwhile the anti-interference performance of the system is improved.

The invention discloses a harmonic suppression method and system based on feedforward control and virtual impedance, and belongs to the field of electric energy quality control, and the method comprises the steps: constructing a harmonic extraction model based on the cascading of double third-order generalized integrators, and obtaining a voltage harmonic component based on the harmonic extraction model and real-time power grid data; based on a preset power outer loop control strategy, a preset voltage and current double closed loop control strategy, a preset harmonic voltage feed-forward control strategy and the voltage harmonic component, constructing a network construction type charging pile control model, and obtaining an initial output current; obtaining each virtual impedance based on the initial output current, the harmonic extraction model and the voltage harmonic component; and obtaining a harmonic suppression model based on each virtual impedance and the network construction type charging pile control model, so as to obtain a harmonic suppression output current based on the harmonic suppression model and the real-time power grid data. According to the harmonic suppression method and system based on feedforward control and virtual impedance provided by the invention, grid-connected output current harmonics controlled by a network-forming type charging pile are effectively suppressed.

The invention discloses a harmonic suppression and dynamic reactive compensation control method for an energy router, which is suitable for a micro-grid and a distributed energy access system. According to the method, three-phase current and voltage signals of an alternating current port of the energy router are collected, five-time and seven-time main harmonic components are extracted through fast Fourier transform, harmonic compensation current instructions equal in amplitude and opposite in phase are generated and injected into an inverter to be output, and active counteracting of main harmonics is achieved. Meanwhile, the bus voltage deviation and the change rate thereof are detected, a reactive current instruction is adjusted on line by adopting a fuzzy self-adaptive PI controller, rapid and smooth dynamic reactive compensation is realized, and the bus voltage is stabilized. Decoupling control of active / reactive and harmonic components is realized in combination with Park conversion, and virtual impedance is introduced to enhance system damping and harmonic suppression capabilities. Compared with the prior art, harmonic suppression and voltage support can be simultaneously realized under a single control framework, the response speed is high, the stability is high, and the method is suitable for high-performance grid-connected operation of the multi-port energy router.

The invention discloses a six-phase motor driver harmonic current suppression method based on multi-subspace control, and belongs to the technical field of motor control. In order to solve the problem that low-order harmonic current of a six-phase motor in a z1-z2 subspace is difficult to effectively suppress, the invention provides a scheme that a mathematical model of the six-phase permanent magnet synchronous motor is established, multi-subspace decomposition is carried out, and stator current is divided into a d-q subspace and the z1-z2 subspace; a double-closed-loop control architecture with a speed loop as an outer loop and a current loop as an inner loop is constructed, a d-q subspace adopts a PID regulator to realize fundamental current control, and z1-z2 subspaces realize suppression of fifth and seventh harmonic currents through a parallel structure of PI and a quasi-proportional resonance controller; and a PWM signal is synthesized through inverse transformation and dual three-phase space vector pulse width modulation, and an inverter is driven to realize stable output of fundamental wave energy and harmonic suppression. The method effectively reduces the harmonic distortion rate, improves the operation efficiency and stability, and is suitable for occasions of new energy vehicles, ship propulsion, rail transit and the like.

The invention relates to the technical field of data center energy storage, and discloses a data center flywheel energy storage system and method based on an LCL filter, and the method comprises the steps: collecting a power grid side current signal, decomposing a harmonic component, and dynamically adjusting the parameters of the LCL filter to suppress harmonic waves; determining and executing a charging and discharging control strategy according to the direct-current bus voltage and the flywheel rotating speed; flywheel vibration and acceleration are monitored in real time, operation stability is evaluated, and a control strategy is corrected; and the harmonic suppression effect is optimized by combining rotating speed feedback and voltage data compensation filter parameters. The system comprises a harmonic suppression module, a charge and discharge control module, a stability evaluation module and a filtering parameter optimization module. Through multi-parameter dynamic adjustment and multi-module cooperative control, composite suppression of power grid harmonics and accurate adjustment of the flywheel energy storage state are achieved, the system operation stability and the filtering effect are improved, and the method is suitable for a data center energy storage scene.

The invention relates to the field of three-level inversion twin-trawling systems, and particularly discloses a harmonic current suppression method, system and product of a three-phase three-level inversion twin-trawling system, and the method specifically comprises the following steps: S1, a bus voltage balance control step; s101, acquiring a bus voltage error value; s102, acquiring a bus voltage error correction value; s2, a neutral current harmonic suppression step; s201, acquiring a common-mode current flowing through a node connected with the power side and the load side; s202, acquiring a higher harmonic component in the common-mode current; s203, obtaining a higher harmonic component suppression correction value; and S3, superposing the corrected value and a three-phase voltage output modulation wave to obtain a three-phase inverter circuit modulation signal of a power side in the three-phase three-level inverter twin trawling system. The harmonic suppression algorithm of the output current can be provided based on the single-power three-phase dragging system, the cost can be reduced, and the current distortion can be reduced, so that the real current output condition can be simulated.

The invention discloses a high-linearity low-noise amplifier based on harmonic suppression, relates to the field of communication and the technical field of electronic devices, and is used for solving the problem that the noise coefficient of an existing Darlington structure is large. Comprising a noise matching and input matching network, a linearity enhancement structure, a negative feedback structure and a pre-distortion structure. Wherein the linearity enhancement structure at least comprises a first amplification transistor and a second amplification transistor which are arranged in parallel, and is used for improving the linearity of the circuit through harmonic cancellation; the negative feedback structure is connected with the noise matching and input matching network and the pre-distortion structure and is used for expanding circuit bandwidth and optimizing output matching; the pre-distortion structure is used for stabilizing the bias voltage of the third amplification transistor. According to the invention, the linearity of the whole circuit is effectively improved, and the source microstrip lines of the two circuits are utilized to improve the minimum noise matching and improve the noise performance. Noise is reduced, linearity is improved, low-frequency gain is suppressed, and bandwidth of the whole circuit is improved.

The invention discloses a dual three-phase permanent magnet synchronous motor harmonic suppression method based on virtual back electromotive force identification, and the method comprises the following steps: S1, building a driving system model of a DTP-PMSM; s2, constructing a harmonic model of the DTP-PMSM, analytically decomposing the nonlinear characteristic and the non-sinusoidal counter electromotive force of the inverter into dq and dqz subspaces, introducing the concept of virtual harmonic counter electromotive force, and unifying the nonlinearity of the inverter, the space harmonic counter electromotive force and cross coupling terms related to harmonic current into a single expression form; and S3, developing an identification principle based on current mapping, including amplitude and phase estimation, gain design and delay compensation, so as to estimate the amplitude and phase deviation of the virtual harmonic back electromotive force on line to realize harmonic suppression and avoid a complex algorithm and a large amount of parameter adjustment. According to the method, the operation effect is good in a wide rotating speed range, and meanwhile complex algorithms and a large amount of parameter adjustment are avoided.

The invention discloses an electric energy quality optimization method and system based on carrier modulation, and relates to the field of electric energy quality optimization, and the method comprises the steps: obtaining bridge arm information of a distributed energy storage type electric energy quality controller, and determining a carrier amplitude adjustment strategy; determining a target zero-sequence component needing to be injected through carrier characteristics based on the carrier amplitude adjustment strategy; according to the target zero-sequence component, performing superposition on the original modulation wave to generate a target modulation wave; adjusting the power of the power grid based on the target modulating wave, and carrying out dynamic compensation on the capacitance voltage deviation; the harmonic suppression capability is improved, and the power distribution dynamic response efficiency is enhanced, so that the optimization of the electric energy quality is realized, and the problem that the real-time performance and the reliability of the electric energy quality regulation are reduced due to the limitation of harmonic compensation and the lack of real-time dynamic response in the conventional pulse width modulation method is solved.

The invention discloses a harmonic suppression method based on virtual impedance cooperative control, relates to the technical field of power grid harmonic control, and is used for solving the technical problems of high harmonic time variation, high treatment energy consumption and parameter solidification in a high-permeability photovoltaic scene. The method comprises the following steps: acquiring an original electric signal and an impedance parameter of a power grid side and a filtering parameter of an inverter side; performing real-time phase correction according to the original electric signal to obtain a multi-band harmonic frequency; virtual impedance is constructed based on the multi-band harmonic frequency, and an impedance characteristic matrix is generated based on the impedance parameters and the filtering parameters; performing parameter optimization based on deep reinforcement learning on the virtual impedance by adopting the impedance characteristic matrix to obtain an optimal virtual impedance parameter; and changing the equivalent output impedance of the inverter through the virtual impedance under the optimal virtual impedance parameter so as to realize harmonic suppression.

The invention discloses a long-time-domain predictive control and undisturbed switching method for a hybrid system networking converter, and belongs to the technical field of power system control. In order to solve the problems of poor dynamic performance and easy impact of mode switching of a grid construction / grid following converter hybrid system under new energy high-proportion grid connection, the method specifically comprises the following steps: constructing long time domain model prediction current control, replacing a traditional PI current inner loop, performing discrete modeling based on a dq coordinate system, performing double-step prediction compensation delay, and updating reference current through Lagrange extrapolation. The current tracking precision and the harmonic suppression capability are improved; designing an undisturbed switching strategy, unifying an alpha-beta coordinate system and a current control loop, locking a switching angle, synchronizing an initial value of an integrator, and dynamically adjusting reference voltage to ensure that variables are continuous; two strategies are integrated in a hybrid framework, and stable operation and smooth switching under strong / weak power grids and transition working conditions are realized. According to the invention, the total harmonic distortion rate of the grid-connected current is reduced to below 0.85%, and the method has the advantages of no voltage and current impact in switching and enhanced stability and flexibility of the power system.

The application discloses a multi-port impedance optimization-based harmonic suppression method for a non-electrolytic capacitor permanent magnet synchronous motor driving system, and belongs to the technical field of motor control. The application is aimed at the problem that active damping control will cause the increase of machine-side harmonics when used for the network-side current harmonic suppression of a non-electrolytic capacitor motor system. The machine-side port impedance regulation voltage and the network-side port impedance regulation voltage are calculated. The entropy weight TOPSIS method is used to calculate the optimal angle of the machine-side and network-side port impedance regulation voltage, and the machine-side and network-side port impedance regulation voltage is synthesized into a cooperative voltage. The cooperative voltage is decomposed into a d-axis component and a q-axis component, and then is superimposed on the dq-axis voltage given value, so that the controlled dq-axis voltage given value is obtained. The regulated alpha-beta axis voltage given value is obtained through the inverse Park transformation link, and then the pulse control signal of the inverter is obtained through the SVPWM control, so that the machine-side and network-side harmonic suppression of the driving system is realized. The application is used for the cooperative suppression of machine-side and network-side harmonics.

The invention relates to a converter grid-connected current harmonic suppression method and device for a traction power supply system, and is applied to the technical field of rail transit traction power supply. The method comprises the following steps: acquiring traction power supply electrical parameter information and grid-connected output current information of each slave controller in a grid-connected converter; determining a grid-connected reference current according to the traction power supply electrical parameter information; and based on the grid-connected reference current, performing harmonic suppression and phase lead compensation on the grid-connected output current information by utilizing closed-loop control of multiple quasi-proportional resonance based on multiple phase lead compensation, and determining the current grid-connected output current. Through multiple quasi-proportional resonance control, the harmonic content of steady-state current output by the grid-connected converter can be suppressed; and in order to avoid control time delay caused by multiple quasi-proportional resonance control, the phase is subjected to lead compensation, so that the obtained current grid-connected output current meets the response speed requirement, and the electric energy quality of the grid-connected current is improved. Therefore, the operation stability of the traction power supply system can be improved.

The invention discloses a five-phase permanent magnet synchronous motor current control method based on virtual impedance. Comprising the following steps: obtaining stability boundaries of virtual impedance of each axis in d1-q1 and d3-q3 synchronous rotating coordinate systems, and obtaining optimal virtual impedance of each axis through simulation; according to the optimal virtual impedance of each coordinate axis, obtaining a proportional-integral control parameter; in the operation process of the five-phase permanent magnet synchronous motor, reference currents and actual currents of all shafts in d1-q1 and d3-q3 synchronous rotating coordinate systems are obtained in real time and input into corresponding two-degree-of-freedom current controllers respectively, and control voltages of all the shafts are obtained; and generating a driving signal according to the control voltage of all coordinate axes in the d1-q1 and d3-q3 synchronous rotating coordinate systems, and controlling the five-phase permanent magnet synchronous motor. According to the method, high-performance harmonic suppression and dynamic response optimization control of the five-phase permanent magnet synchronous motor under the influence of multiple odd harmonic currents is realized.

The invention discloses a five-phase permanent magnet synchronous motor harmonic suppression control method based on machine learning, and the method comprises the following steps: S1, constructing a mathematical model of a five-phase permanent magnet synchronous motor drive system in a rotating coordinate system, and designing a five-phase permanent magnet synchronous motor control system based on a deep neural network; and S2, deeply fusing the physical prior information of the motor into a training process to enhance the generalization ability of the model, and proposing a hybrid optimization strategy to improve the fitting precision of the predicted network voltage and the actual working voltage, suppress the fluctuation in the prediction process, and enable the predicted value to better meet the actual operation requirement. The invention overcomes the limitation of the existing dual-plane current control method, and makes full use of the technical advantages of the method.

The invention relates to the technical field of energy storage systems, and discloses a harmonic suppression method and system of an energy storage converter. According to the method, harmonic disturbance generated during switching of the switching state is analyzed based on the voltage modulation instruction and the switching characteristic parameters, so that prospective prediction of voltage harmonics caused by switching action time sequence deviation is realized, and the problem of detection and control delay existing in a traditional method is solved; carrying out credibility evaluation on the obtained prediction information of the voltage harmonic wave based on the real-time current harmonic component and the voltage harmonic wave disturbance prediction quantity, and fusing the real-time current harmonic component and the voltage harmonic wave disturbance prediction quantity based on the result to generate a harmonic wave suppression target with a quick response characteristic and high precision; and a safety voltage control instruction capable of effectively suppressing a harmonic suppression target is obtained through a closed-loop iterative optimization mechanism, so that the inherent contradiction that the harmonic suppression effect and the safety constraint are difficult to consider at the same time is solved, and the comprehensive performance of harmonic suppression is improved.

The invention relates to the technical field of frequency converter resonance control, and provides a frequency converter long-line driving system resonance suppression method and device, and the method comprises the steps: obtaining time sequence data, carrying out the normalization processing, calculating a theoretical resonant frequency, and predicting the resonant frequency through an attention-enhanced long-short-term memory neural network. Calculating a frequency error compensation amount, and calculating a harmonic suppression comprehensive performance evaluation index according to the frequency error compensation amount and the predicted resonant frequency; the harmonic suppression effect is evaluated according to the harmonic suppression comprehensive performance evaluation index and the index threshold value, and the weight coefficient of the attention-enhanced long-short-term memory neural network is adjusted through an NSGA-II optimization algorithm; and adjusting the center frequency and bandwidth parameters of the frequency converter long-line driving system according to the predicted resonant frequency to realize resonance suppression of the frequency converter long-line driving system. According to the invention, the feature extraction capability of the LSTM network is enhanced through the attention mechanism, the accuracy of resonant frequency prediction is significantly improved, and the harmonic suppression effect is improved.

The invention relates to the technical field of flexible direct current transmission harmonic suppression, and provides a flexible direct current transmission control device with broadband harmonic suppression, the control device integrates inner ring control and harmonic suppression, and the harmonic suppression adopts data collected by the inner ring control to carry out harmonic suppression. Comprising an acquisition module, an inner loop control module and a harmonic suppression module, the acquisition module is used for acquiring power grid data in real time, and the inner loop control module is used for generating original bridge arm modulation waves according to the power grid data acquired by the acquisition module and transmitting the modulation waves to a valve control device for inner loop control; the harmonic suppression module is used for determining harmonic waves needing to be suppressed according to power grid data, generating compensation voltage according to current harmonic components and system impedance, superposing the compensation voltage and original bridge arm modulation waves and sending the superposed compensation voltage and original bridge arm modulation waves to the valve control device, and controlling switching of the converter valve sub-module by the valve control device based on superposed signals. Resonance suppression is realized while inner loop control is performed.

The invention discloses a direct-current bus harmonic suppression method and system for photovoltaic grid connection in an industrial park, and relates to the technical field of harmonic suppression of a direct-current bus of a photovoltaic power supply and improvement of the power quality of a power distribution network, and the method comprises the steps: generating required direct-current output through series voltage boosting and parallel current increasing, constructing a photovoltaic power generation unit, and adding a DC-DC converter, based on MPPT, a three-layer control method is adopted to track the maximum power point and control a DC-DC converter switching device; for a DC-DC converter and a DC-AC inverter, system mathematical modeling and theoretical analysis are carried out, and a DC side current is deduced; and based on the collected DC side current, extracting a specific harmonic component and generating a reverse compensation signal, and injecting the signal into a corresponding DC bus control link for harmonic suppression. According to the method, the DC bus voltage ripple coefficient is reduced, harmonic waves generated by MPPT, phase-locked loop disturbance and switch modulation are suppressed, the total harmonic distortion rate of the output current of the inverter can be reduced, and the stability margin of the system under the weak power grid condition is improved.