365 results about "Harmonic mitigation" patented technology

The invention provides a big data intelligent decision analysis method and system. The method comprises the following steps: acquiring vibration data and mechanical node stress distribution data in power equipment transportation, and extracting high-frequency harmonic distortion characteristics aligned with a vibration data timestamp; performing cross-domain correlation analysis on stress data fluctuation and harmonic characteristic dynamic change, and identifying a symbiotic mode of mechanical stress abnormality and electrical harmonic distortion by using a machine learning model; based on logistics path planning and equipment constraints, a cooperative control instruction for adjusting the transportation path and the power supply loop parameters is generated through a multi-target cooperative optimization algorithm; and constructing a joint risk assessment matrix, and dynamically adjusting the cooperative relationship between the transportation path and the harmonic suppression parameter according to the quantitative analysis result and the cooperative control instruction to realize the closed-loop decision of the power equipment. According to the technical scheme provided by the invention, the power equipment transportation data processing efficiency is remarkably improved.

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 discloses a decoupling control method and system for a matrix motor with harmonic suppression capability, and belongs to the technical field of motor driving systems, and the method comprises the steps: building a matrix motor current loop mathematical model which considers a DC disturbance term and an AC disturbance term at the same time; based on the matrix motor current loop mathematical model, establishing a self-adaptive quasi-resonance extended state observer which simultaneously considers direct current disturbance observation and alternating current disturbance observation and performs self-adaptive adjustment on control parameters; the direct current and alternating current lumped disturbance of a matrix motor current loop is observed in real time through an adaptive quasi-resonance extended state observer; compensating the observed direct current and alternating current lumped disturbance in a forward controller of the current loop and obtaining a voltage control quantity; and controlling the matrix motor through a voltage vector space transformation and SVPWM modulation method according to the voltage control quantity. The method is improved and optimized based on an existing matrix motor vector control system, and the system does not need to be modified on a large scale.

The invention discloses a GaN totem-pole bridgeless PFC converter harmonic suppression method based on adaptive virtual admittance, and belongs to the technical field of converter control. The invention aims to solve the problem that LC resonance in a GaN totem-pole bridgeless PFC converter in a wide load range causes power grid voltage distortion to be converted into grid-side current harmonics. Comprising the following steps: decoupling a virtual admittance vector in a polar coordinate system, and optimizing under different load working conditions to obtain an optimal virtual admittance set; the system delay influence is compensated to ensure the robustness of the proposed method under different operation conditions; and a load power adaptive virtual admittance mechanism is constructed based on a segmented cubic Hermite interpolation method, so that suppression of network-side specific current harmonics in a wide load range is realized. The self-adaptive suppression method is used for self-adaptive suppression of the grid-side current harmonics of the GaN totem-pole bridgeless PFC converter.

The invention discloses a harmonic control method and system of a frequency converter. The method comprises the following steps: acquiring an output voltage signal and a bus voltage signal of the frequency converter in a current time period; performing spectral analysis on the output voltage signal, and constructing a first frequency distribution characteristic curve; correcting the first frequency distribution characteristic curve according to the bus voltage signal to obtain a second frequency distribution characteristic curve; if the output frequency signal of the frequency converter generates frequency drift, tracking the frequency drift of the output frequency signal to obtain a frequency drift rule; performing voltage waveform distortion analysis on the output voltage signal to obtain a total harmonic distortion rate; performing parameter optimization on the filter according to the total harmonic distortion rate and the frequency drift rule, so that the third frequency distribution characteristic of the filter is matched with the second frequency distribution characteristic; in the next time period, the optimized filter is adopted to carry out frequency converter harmonic suppression; the harmonic suppression effect of the frequency converter can be effectively improved, and the power supply quality of a power grid is improved.

The invention discloses a power supply reliability analysis method and system based on operation and maintenance characteristics of a power distribution network, and particularly relates to the technical field of power supply analysis of the power distribution network. Harmonic data, including harmonic current, harmonic voltage and frequency components, of each node in a power distribution network system are collected in real time; in combination with the topological structure of the power distribution network, the sparse linear equation set is solved through L1 norm optimization, and the main source of harmonic waves is identified; the contribution degree of each nonlinear load to the harmonic distortion of a power distribution network system is calculated, a list of key harmonic sources is screened out through Pareto analysis, a filter configuration optimization model is constructed based on the identified key harmonic sources, and the harmonic distortion level and the filter installation cost are used as constraint functions to optimize the filter configuration. The installation position and the parameter configuration of the filter serve as decision variables, an optimization algorithm is adopted for solving, and the recommended installation position and the parameter configuration of the filter are output; the harmonic suppression effects under different load conditions are evaluated, and the problem that the power supply reliability is reduced due to harmonic distortion is effectively solved.

The invention discloses a power-saving device and method for high-voltage power utilization, and relates to the technical field of power grid control, a self-adaptive dynamic control strategy and a load prediction function are introduced, and a reactive compensation module can adjust the compensation amount according to the real-time change of the load demand; when the load fluctuates violently, a response can be quickly made, unnecessary energy consumption is reduced, the main line and the load end are respectively provided with compensation equipment, and distributed compensation and main line compensation are dynamically matched through load fluctuation prediction and a self-adaptive control technology; when the load changes, the load end equipment preferentially and quickly responds, the coordination of compensation is effectively improved, redundant power loss is avoided, and the harmonic management module realizes accurate harmonic suppression through real-time harmonic data monitoring and parameter adaptive adjustment of the intelligent filter; the intelligent filter automatically adjusts the damping coefficient and the frequency gain according to the frequency and the power density of each harmonic component, and the harmonic component of the specific frequency is inhibited in time; and the harmonic wave fluctuation coping capability of the system is improved.

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 discloses a harmonic suppression method for a network construction type optical storage converter, and belongs to the technical field of new energy. According to the method, the operation of the photovoltaic inverter is adjusted through a constant voltage control strategy, remarkable advantages are shown, the energy loss is effectively reduced by inhibiting the photovoltaic inter-harmonics, and the operation stability of the system is improved. The photovoltaic power fluctuation can be obviously reduced, the energy storage control cost is effectively reduced, and the service life of energy storage equipment is prolonged. Meanwhile, the grid-connected performance is excellent, the distortion rate of grid-connected voltage and current can be reduced, and the electric energy grid-connected quality is improved. In addition, a network construction control method is introduced into the system, the network voltage can be effectively supported, the network frequency can be flexibly adjusted, and the adaptability and supporting capacity of the system to network operation are enhanced. According to the invention, stable operation requirements in different grid-connected environments can be met. The method has important technical innovation in the aspects of improving the operation efficiency, the reliability and the system coordination, and has extremely high application and popularization values.

The invention provides a three-phase SVPWM grid-connected inverter harmonic control method based on an improved particle swarm algorithm, and relates to the field of grid-connected control. On the basis of double closed-loop control of a three-phase SVPWM grid-connected inverter, a main circuit topological structure of the grid-connected inverter is firstly provided, and a mathematical model of the grid-connected inverter is determined; then determining a double-closed-loop control strategy based on space vector modulation according to the mathematical model; and aiming at a voltage outer loop and a current inner loop of the double-closed-loop control strategy, an improved particle swarm optimization algorithm is adopted to optimize PI parameters. According to the improved inertia weight, the minimum value, the maximum value and the fitness function of the inertia weight are comprehensively considered, a harmonic suppression performance index is added to the fitness function, and the improved particle swarm optimization algorithm enhances the global search capability and the accurate search capability, so that the probability of falling into a locally optimal solution is reduced. According to the control method, the grid-connected process of the grid-connected inverter can be more stable, the anti-interference capability is enhanced, the static error is reduced, and the electric energy quality is improved.

The invention discloses a high-frequency current harmonic suppression method for a modularized double-winding permanent magnet synchronous motor, and relates to the field of double-winding permanent magnet synchronous motor control. The problems that the cost is increased and energy conversion is not considered due to the fact that multiple inverters are adopted in an existing control strategy are solved. The method comprises the following steps: constructing a double-winding permanent magnet synchronous motor control system, wherein the power supply topology of the double-winding permanent magnet synchronous motor control system is an isolated interleaved parallel topology; obtaining a motor rotor position angle and a rotating speed signal, and calculating a difference value between a rotating speed given signal and a rotating speed feedback signal to obtain d-axis and q-axis current given values of two sets of windings; 6-phase current values are obtained, actual values of d-axis current and q-axis current of the two sets of windings are obtained according to the coordinate transformation matrix, and the difference value of the d-axis current and the q-axis current is solved to serve as input of a current loop PI controller; performing coordinate transformation on the output of the current loop PI controller, and calculating a voltage modulation ratio; and selecting a proper voltage modulation strategy and a carrier phase shift angle to carry out high-frequency current harmonic suppression. The method is applied to the high-frequency current harmonic suppression field.

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 provides a harmonic suppression method and device for a network-forming converter, and belongs to the field of power grids. The method comprises the following steps: acquiring a three-phase output voltage of a target converter, and determining a harmonic component according to the three-phase output voltage of the target converter; determining a first reference voltage correction value according to the harmonic component; correcting the target reference voltage according to the first reference voltage correction value to obtain a corrected target reference voltage; and inputting the corrected target reference voltage into a control loop, and controlling the target converter. According to the method, the target voltage reference value is adjusted according to the harmonic component, feedback is introduced, and the impedance of the grid-forming converter is equivalently reduced, so that the impedance of the power grid is equivalently increased, more harmonic current is absorbed by the grid-forming converter, and the quality of grid-side current is effectively improved.

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 harmonic suppression method and device, a permanent magnet synchronous motor and a storage medium, and relates to the technical field of motor control, and the harmonic suppression method is applied to the permanent magnet synchronous motor, and comprises the steps: carrying out the harmonic extraction of a stator current of the permanent magnet synchronous motor, and obtaining a fifth harmonic current component of the stator current; determining the quintuple harmonic voltage compensation amount of the stator current according to the quintuple harmonic current component of the stator current; and performing voltage feed-forward compensation on the permanent magnet synchronous motor based on the quintuple harmonic voltage compensation amount of the stator current. On the basis of ensuring that the influence of the higher harmonic current generated in the operation process of the permanent magnet synchronous motor on the rotating speed and the torque of the motor is controlled within an acceptable range, the engineering realization difficulty is effectively reduced.

The invention discloses a harmonic suppression predictive control method and module for a three-phase grid-connected inverter system, and belongs to the field of power electronic control. The method comprises the following steps: firstly, establishing a continuous domain state space model of a three-phase grid-connected inverter system under a dq coordinate system, discretizing the state space model at a k moment, and obtaining a prediction model of a k + 1 sampling power grid current; enabling the power grid current prediction model to reach a power grid current reference value at a k + 1 sampling moment, and calculating a reference inverter voltage control reference value; calculating a voltage control reference value of the inverter integrated with harmonic suppression by combining the voltage control reference value of the reference inverter and the discretized quasi-resonance controller; determining an optimal voltage vector and action time of an inverter voltage control reference value capable of synthesizing the integrated harmonic suppression; and generating a control pulse signal and applying the control pulse signal to a switching tube of the three-phase grid-connected inverter to realize harmonic suppression prediction control of the three-phase grid-connected inverter system. The steps are simple, and the harmonic prediction and suppression control effect is good.

The invention discloses an SVG converter valve parameter configuration method and device. The method comprises the steps that the capacity and rated working voltage of a converter valve are determined according to the basic function requirement of an SVG; according to the capacity and the rated working voltage of the converter valve, determining the type and the rated working voltage of each sub-module, and combining third harmonic injection and harmonic suppression to determine the number of the sub-modules; determining the capacitance value of the sub-module and the parameters of the bridge arm reactor according to the volatility of the capacitance voltage of the sub-module in the steady state and the harmonic suppression requirement; according to overvoltage and overcurrent characteristics of the SVG, the number of sub-modules, capacitance values and bridge arm reactor parameters are optimized; and according to overvoltage characteristics of the SVG after parameter optimization, determining lightning arrester configuration, and obtaining converter valve parameter configuration of the SVG. The method is suitable for extra-high voltage SLCC direct current power transmission system design, and the system design efficiency and standardization can be effectively improved.

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 ship propulsion motor sensorless control algorithm based on harmonic suppression, and the algorithm comprises the steps: introducing a compensation coefficient through the analysis of fifth and seventh harmonics, constructing a novel PIR controller, and suppressing the formulated frequency harmonics; the external disturbance of the system is regarded as a system expansion state, a novel observer is constructed by combining cascade ESO and PLL to estimate the position of a motor rotor, it is guaranteed that the system accurately compensates for the deviation angle in a dynamic state and a static state, and the performance of the position-sensorless driving system is improved. According to the invention, a compensation coefficient is introduced, a novel PIR controller is constructed, and control links for five-frequency multiplication and seven-frequency multiplication are added, so that the effects of suppressing PMSM phase current harmonics and reducing the total harmonic content of phase current are achieved. And then external disturbance of the system is regarded as a system expansion state, and the rotor angle of the motor is estimated by combining cascade ESO and PLL. Therefore, the system can accurately compensate the deviation angle in a steady state and a dynamic state, and the performance of the position-sensorless driving system is improved.

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.

To reduce cost of an entire harmonic filter facility and downsize the harmonic filter facility.SOLUTION: A harmonic filter facility suppressing harmonic components included in AC voltage of a bus that is a harmonic suppression target has an LC series circuit composed of a first reactor element connected to the bus and a capacitor element connected to a low pressure side of the first reactor element, and a second reactor element connected to the capacitor element in parallel in the low pressure side of the first reactor element. Anti-resonance orders of the capacitor element and the second reactor element are set to a higher order than a fundamental frequency.SELECTED DRAWING: Figure 1

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.