142 results about "Harmonic control" patented technology

The invention relates to the technical field of frequency converter harmonic control, in particular to a harmonic control method, system and device applied to a frequency converter, and the method comprises the steps: obtaining the current data of a rectification input side and an inversion output side of the frequency converter; obtaining the difference coefficient of the overall pulsation amplitude change of each period and the irregular coefficient of the corresponding pulsation time change, and further obtaining the harmonic influence coefficient of the rectification input side current of each period with the pulsation amplitude difference and irregular characteristics; calculating a deviation coefficient and a jitter abnormal coefficient of the inversion output side current of each period so as to obtain a harmonic influence coefficient of the inversion output side current of each period having waveform deviation and rapid jitter; therefore, the harmonic delay superposition interference coefficient is obtained, and the output current of the inverter is corrected in combination with the current data of the inverter output side. The harmonic control precision of the frequency converter can be improved.

The invention discloses a self-adaptive harmonic current suppression method for harmonic waves of a photovoltaic inverter, which belongs to the technical field of power quality control of a power system and comprises the following steps of: compensating a control strategy through a self-adaptive harmonic component of the photovoltaic inverter by adopting a'detection-reverse injection 'framework; the difference between the residual apparent capacity of the inverter after fundamental wave power supply and the borne harmonic power is used as an adaptive quantity, and the total harmonic distortion rate of the grid-connected point is reduced to the maximum extent on the premise of no overload; the method comprises the following steps: firstly, constructing a real-time harmonic detector based on a cascade generalized integrator; secondly, an inverter impedance model is established from the aspect of impedance stability, and a control parameter stability boundary is determined; then, a self-adaptive harmonic control strategy is introduced into the single-inverter grid-connected system, and a reasonable parameter setting method is provided on the basis of considering stability limitation; afterwards, a capacity-matched harmonic power distribution algorithm is provided for a multi-inverter parallel system, and the efficiency and operation stability of a photovoltaic grid-connected power generation system are improved.

The invention provides a motor control device which can simultaneously realize reduction of time required for design and adjustment of correction amounts of amplitude and phase corresponding to response characteristics and guarantee of a torque ripple suppression effect. A motor control device (1) drives a motor (5) using an inverter (4). A motor control device (1) is provided with: a harmonic control command value calculation unit (8) that finds first harmonic control command values (i * dqh, phi * dqh) on the basis of a torque command value (tau *) and an electrical angle ([theta] e) of a motor (5); a response compensation unit (9) that calculates second harmonic control command values (i * * dqh, phi * * dqh) obtained by performing response characteristic compensation on the first harmonic control command value (i * dqh) in accordance with the rotational speed of the motor (5); and a voltage command calculation unit (3) that calculates a voltage command value (v * dq) on the basis of a torque control command for outputting the torque command value (tau *) and the second harmonic control command values (i * * dqh, phi * * dqh).

The present application discloses a method, apparatus, device and storage medium for cross-correlated harmonic control in power grids. The method includes: performing wavelet packet decomposition on subnet electrical signals to obtain the harmonic components of the subnet in each frequency band; calculating the harmonic phase difference between subnets based on the cross-correlation function and topological impedance matrix between the harmonic components of each subnet, and calculating the total harmonic distortion rate based on the harmonic components of the subnet in each frequency band; constructing a harmonic transfer equation based on the harmonic phase difference between subnets and the equivalent output impedance of the inverter to calculate the harmonic responsibility ratio of the subnet; solving a two-layer game model based on the total harmonic distortion rate and its reference value and the harmonic responsibility ratio of the subnet to obtain the output of the control equipment; inputting the output of the control equipment into the fuzzy controller to obtain the impedance adjustment amount of the subnet, and adjusting the virtual impedance according to the impedance adjustment amount to update the harmonic return path. The present application realizes the harmonic control between multiple subnets during high-penetration distributed grid connection, thereby improving the stability of power grid operation.

The invention provides a grid-side current harmonic suppression method and device for a motor driving system without an electrolytic capacitor. The method comprises the following steps: determining first and second bus voltage harmonics based on bus voltage obtained by sampling and inverter switching frequency; correcting the bus voltage according to the first bus voltage harmonic wave and the second bus voltage harmonic wave so as to determine a reconstructed bus voltage; according to the second bus voltage harmonic, the reconstructed bus voltage, an inverter output three-phase duty ratio and a motor three-phase current, first and second network side current harmonic regulation and control voltages are determined based on a self-defined closed-loop controller; and adopting a motor alpha-axis correction voltage and a motor beta-axis correction voltage determined according to the first and second grid-side current harmonic regulation and control voltages to participate in motor SVPWM modulation to output the three-phase duty ratio of an inverter so as to suppress grid-side input current harmonics. According to the method and the device, factors such as motor operation conditions, bus voltage harmonic waves and digital control delay are comprehensively considered, the quality of grid-side input electric energy is improved, and disturbance to machine-side rotating speed and torque is reduced.

The invention provides a photovoltaic inverter common-mode resonance suppression method and device and a storage medium. The method comprises the steps of obtaining resonance current data of a common-mode loop; determining a differential negative feedback control strategy of a common-mode loop based on the resonance current data and preset common-mode current data; determining a harmonic control strategy of the system according to the first voltage data of the DC unit and the second voltage data of the power grid; determining a pulse width modulation strategy of the system based on a differential negative feedback control strategy and / or a harmonic control strategy so as to suppress common-mode resonance generated during voltage fluctuation; according to the method, the problems of current oscillation and inverter damage caused by common-mode resonance are effectively solved by obtaining the common-mode loop resonance current data and adopting the differential negative feedback control strategy to suppress resonance frequency point oscillation, combining the harmonic control strategy to eliminate the alternating current component, and finally dynamically adjusting the pulse width modulation strategy; the method has the advantage of improving the stability and safety of the system.

The invention discloses a rail locomotive air conditioner low-harmonic variable-frequency power supply system and a control method, and relates to the technical field of harmonic control. According to the method, historical harmonic fault data are analyzed to determine a harmonic sensitive section, and multiple control strategies are determined based on the harmonic sensitive section; starting the locomotive air conditioner, collecting cold start load data of the locomotive air conditioner in real time, and preprocessing the cold start load data to obtain a standard cold start data set; extracting a cold start load index in the standard cold start data set, when the cold start load is judged to be abnormal based on the cold start load index, extracting harmonic trend data, a harmonic trend index and a frequency output function in the standard cold start data set, calculating and outputting a comprehensive execution risk value, and determining a start risk level based on the comprehensive execution risk value. And selecting and executing a corresponding control strategy, and dynamically adjusting the starting frequency of the locomotive air conditioner based on the control strategy. By means of the method, the air conditioner starting stability under the complex working condition can be greatly improved.

The invention discloses a power distribution system harmonic source positioning method based on subsystem division, and aims to improve the accuracy and anti-interference capability of harmonic source identification in a power distribution system. According to the method, firstly, an obtained voltage signal is preprocessed, frequency domain feature information is extracted, a subspace projection operator is constructed through singular value decomposition, and effective extraction of each harmonic component in the signal is achieved. Then, carrying out subsystem division on the power distribution system according to the position of the tail end measurement point, for each subsystem, respectively injecting simulated harmonic current into each candidate node by adopting a virtual harmonic injection method, and calculating the response of the node to the tail end voltage; and comparing a simulation result with a measured value, constructing an error vector, screening out a node with the minimum error as a backup harmonic source node, and finally positioning the harmonic source node through zero setting of a connection node and a correction strategy of the most downstream node. The method is suitable for a multi-node and multi-source coexistence large-scale power distribution network harmonic suppression scene.

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 relates to an AC motor synchronous modulation method based on a phase-locked loop and a PWM generator, and belongs to the technical field of motor control, and the method comprises the steps: determining a voltage phase angle outputted by an AC motor based on an output voltage of vector control of the AC motor, and converting the voltage phase angle into a synchronous phase angle of a carrier wave based on a carrier wave ratio; the synchronous phase angle is used for determining a sine input signal of the phase-locked loop; determining a cycle count increment adjustment value of the carrier based on the sinusoidal input signal; and correcting the cycle count increment value of the carrier based on the cycle count increment adjustment value. According to the alternating current motor synchronous modulation method based on the phase-locked loop, the period ratio and the phase relation of the carrier wave and the modulation wave are fixed, so that the harmonic content of the output voltage and the harmonic content of the output current are kept consistent in the synchronous modulation process, extra harmonic voltage and current cannot be generated, and overall harmonic treatment of a system is facilitated.

The invention discloses a novel power grid harmonic compensation method and system based on harmonic responsibility division, and relates to the technical field of power grid harmonic compensation, and the method comprises the steps: collecting voltage and current signals at a common connection point of a power grid, and extracting each harmonic component from the voltage and current signals; based on each harmonic component, identifying harmonic impedance of a system side and a user side, and calculating a responsibility factor sequence corresponding to each harmonic; performing statistical analysis on the responsibility factor sequence in a preset time window to generate responsibility fluctuation entropy representing responsibility stability; dynamically correcting the compensation priority of each harmonic according to the responsibility factor and the responsibility fluctuation entropy corresponding to the responsibility factor; generating a harmonic compensation instruction of a non-user responsibility part according to the responsibility factor and the harmonic component after priority correction, and distributing available compensation capacity according to the priority when the capacity of a compensation device is limited; the method is applied to a system comprising a plurality of distributed power supplies with harmonic regulation and control capability.

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 an integrated intelligent power management system and a harmonic control method. The method comprises the following steps: acquiring analog signals of voltage and current; digital signal sequences of voltages and currents in the N power distribution nodes are generated; obtaining a K-order frequency domain harmonic component of each power distribution node; judging abnormal harmonic nodes; if the abnormal harmonic nodes exist in the N power distribution nodes, constructing a harmonic description matrix for abnormal harmonic source positioning; inputting the harmonic description matrix into a pre-trained abnormal harmonic source positioning model, and outputting an abnormal node identifier where an abnormal harmonic source is located; according to the method, the judgment of the abnormal harmonic nodes is converted from single-index passive alarm to multi-feature driven active identification, and the management level of a power system is improved.

The embodiment of the invention provides a harmonic control method and device of an electric power system and a storage medium, the electric power system comprises a converter for converting direct current into alternating current, and the method comprises the following steps: determining a frequency range of a resonance point of the electric power system; under the condition that the switching frequency of the converter falls into the frequency range, determining a target resonant frequency of the resonant point; determining the type and electrical parameters of a nonlinear device needing to be added by taking the target resonant frequency as an optimization target; and setting the non-linear device in the power system. According to the method, a relatively serious resonance point in a power system is identified, and the vibration frequency of the resonance point of the power system is changed in a mode of increasing a nonlinear device, so that the frequency point of an original resonance source in a circuit is avoided, and the harmonic problem in a specific scene is solved in a low-cost mode; and long-term stable operation of a power system can be ensured.

The application discloses a variable frequency device dead zone compensation method, which acquires real-time data of a load current, obtains characteristic harmonics of dead zone generated current according to the real-time data of the load current, inputs the characteristic harmonics after taking the opposite to a regulator, then obtains a characteristic harmonic control quantity, and finally obtains a compensation time point or a compensation amplitude of the dead zone compensation according to the characteristic harmonic control quantity. The application improves the precision of the dead zone compensation, further reduces the harmonics of the system, has low sensitivity to the load characteristic change, and does not need to acquire a special dead zone compensation table.

The application relates to a continuous inverse class-F power amplifier based on source harmonic phase difference control and belongs to the wireless communication field. The power amplifier uses a special source matching network to control a transistor gate waveform, the source matching network is composed of a DC blocking network, a bias network and a harmonic control network; under the condition of a continuous inverse class-F load impedance, the source matching network designed by the application controls the second harmonic phase difference value of the transistor input end by using a series ladder microstrip line to form a T-shaped structure, so that excellent efficiency can be obtained, the load impedance design space can be expanded, and the complexity of a load matching network can be reduced.

This invention discloses a high-efficiency power amplifier with extended harmonic modulation bandwidth and its modulation method. A harmonic control circuit unit is added to the input terminal of the final stage die of the power amplifier. The extended harmonic control unit includes a second harmonic modulation circuit and a first parasitic element of the power amplifier back hole. The second parasitic element of the source back hole of the final stage transistor participates in modulation. Considering the parasitic effect of the power amplifier and the back hole at the source of the die, the harmonic modulation bandwidth is further widened by adjusting the harmonic control circuit unit, which effectively improves the working efficiency of the amplifier.

The invention relates to the technical field of power distribution cabinet internal harmonic control, in particular to a power distribution cabinet harmonic suppression method based on multi-source data fusion. By extracting amplitude and phase information at each harmonic frequency point, branch equivalent admittance is calculated, and an admittance distribution state is formed; judging an abnormal branch with admittance deviation at each frequency point, and establishing a corresponding relation between the adjustable electrical parameters and the admittance deviation; in the operation process of the power distribution cabinet, the admittance distribution state and the abnormal branch set are periodically updated, the equivalent admittance of the target branch is dynamically adjusted according to the corresponding relation, and the distribution of the harmonic current among the branches is changed; through the method, the harmonic peak value and the multi-node superposition effect in the power distribution cabinet can be actively reduced, online operation under the condition of multi-frequency and multi-node load fluctuation is adapted, harmonic flow direction reconstruction is achieved on the premise that complex filtering or hardware devices are not added, and the electric energy quality and the system stability of the power distribution cabinet are improved.

The invention discloses a broadband high-voltage direct-current side impedance characteristic measuring device and a control method thereof. A direct-current voltage control module is used for generating a direct-current voltage instruction value; the harmonic current control module is used for generating a harmonic voltage instruction value; the starting control module is used for charging the half-bridge MMC module group and the full-bridge MMC module group in sequence by taking the sum of the direct-current voltage instruction value and the harmonic voltage instruction value as an output voltage instruction value, and enabling the output voltage of the half-bridge MMC module group to reach the output voltage instruction value after charging is completed; the valve-level modulation control module is used for generating modulation waves of the full-bridge MMC module group according to the harmonic voltage instruction value, so that the full-bridge MMC module group outputs harmonic current; after the harmonic current is injected into the tested equipment, harmonic voltages of the tested equipment at different frequencies are obtained, and the impedance characteristic of the broadband high-voltage direct current side is determined by using the harmonic current and the harmonic voltages. The harmonic control precision is improved, the cost is saved, the equipment structure is simplified, and the method is suitable for impedance measurement in a high-voltage direct-current scene.

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate, and a class-F amplifier (500) according to an embodiment of the present disclosure may comprise: an input matching network (IMN) (510) including an input harmonic tuning network (511) and an input fundamental matching network (512); a power amplifier (PA) (520) electrically connected to the input matching network (510); and a class-F output matching network (F-OMN) (530) electrically connected to the power amplifier (520).

The invention discloses a harmonic collaborative suppression method for grid connection of a new energy power station, which relates to the field of grid-connected harmonic control, and comprises the following steps of: acquiring voltage and current instantaneous values of a grid-connected side of the new energy power station and output power and switching frequency of a photovoltaic inverter and a wind power converter; constructing a mapping model of the dynamic characteristics, the amplitude and the time of each harmonic source; according to the method, dynamic characteristics of each harmonic source are captured through time domain and frequency domain combined analysis, harmonic transmission paths and coupling strength are quantified by combining power grid impedance and load fluctuation parameters, and suppression priorities are reasonably divided according to harmonic contribution degree and tolerance margin.

The invention provides a harmonic current control method, a controller and an inverter, and is applied to the technical field of inverters, and the method comprises the steps: taking a half switching period of the inverter as a sampling period, carrying out the sampling of the output current of the inverter, obtaining a first sampling result corresponding to the current sampling period and a second sampling result corresponding to the last sampling period, the current sampling period is adjacent to the previous sampling period, and the determination of the target sampling current multiplexes the sampling result of the previous sampling period, so that the harmonic control signal is generated based on the target sampling current. Therefore, the sampling result in the complete switching period duration is obtained in the half switching period, the duration for determining the target sampling current is effectively shortened, the delay duration for generating the harmonic control signal is further shortened, the timeliness of the harmonic control process is ensured, and the stability of the harmonic control process and the harmonic current suppression effect are improved.

The invention relates to the technical field of harmonic treatment of charging equipment, and discloses a charging pile filtering treatment device which comprises a filtering treatment device body, the bottom of the filtering treatment device body extends downwards to form a mounting cavity, a water cooling machine is arranged in the mounting cavity, and a cooling pipe of the water cooling machine extends into the filtering treatment device body. After being coiled in the water cooling pipe, the water cooling pipe penetrates out and flows back to the water cooling machine; the filtering treatment device comprises a filtering treatment device body, the outer wall of the filtering treatment device body is provided with a plurality of heat dissipation pipes communicated with the interior of the filtering treatment device body, and an outlet of each heat dissipation pipe is formed in the top of one end located in the filtering treatment device body and is perpendicular to an inlet formed in the corresponding heat dissipation pipe; the device can adapt to an outdoor installation environment, the probability that rainwater permeates into the device is avoided, efficient heat dissipation can be achieved, and the application reliability and effectiveness of the device in a new energy automobile charging pile scene are guaranteed.

The invention provides a filtering control device and a filtering control method based on a controllable reactor, and relates to the technical field of harmonic suppression of a power system. According to the technical scheme provided by the invention, the basic harmonic current and power are measured near the resonance point, and the task contribution proportion of each harmonic source can be quantified in combination with the calculation of the target harmonic power of the harmonic sources at the two sides of the line. According to the distribution mode based on the contribution proportion, distribution of the filtering tasks is more reasonable, and resource waste possibly occurring in a traditional method is avoided. And according to the determined task contribution proportion and the basic harmonic current, a controllable reactor filtering target and a filtering current required by each harmonic source can be accurately calculated, so that accurate treatment of harmonic waves is realized. Compared with a filtering mode in the related technology, the technical scheme provided by the invention can flexibly filter harmonics of different times for different harmonic sources, so that the filtering effect of the line can be improved.

To provide novel types, structures, and arrangments of capacitor networks for harmonic control and the other purpose.SOLUTION: An integrated device includes: a capacitor network; and one or more power devices. The capacitor network includes: a bond pad; and metal-insulation-metal (MIM) capacitors. The capacitor includes: a first metal layer; a second metal layer; an insulation layer between the first and second metal layers; and one or more substrate penetration vias. The first metal layer is connected to the bond pad, and the second metal layer is connected to a ground plane on a bottom side of a substrate by the vias. A plurality of capacitors for an adaptive electrostatic capacity can be arranged around the bond pad in the capacitor network. A matching network in the integrated device can incorporate the capacitor network to reduce a loss, provides better harmonic termination, and achieve better phase alignment of the power devices.SELECTED DRAWING: Figure 2

This invention discloses an ultrawide, high-efficiency inverse Class-F power amplifier based on an elliptic low-pass filter matching network. The gate DC bias network provides the gate bias voltage required for the power amplifier transistor to operate; the drain DC bias network provides the drain bias voltage required for the power amplifier transistor to operate; the input impedance matching network includes a microstrip line, a DC blocking capacitor, and an RC parallel circuit; the output impedance matching network includes a harmonic control network and an elliptic low-pass filter matching network. The harmonic control network selects two frequency points outside the passband for second harmonic control; the elliptic low-pass filter matching network is based on an improved sixth-order Chebyshev low-pass filter, generating two transmission zeros outside the operating frequency band to achieve the conversion from fundamental impedance to second harmonic impedance. This invention enables the power amplifier to achieve high efficiency and high gain within a bandwidth exceeding five harmonics.

The present invention provides a method for controlling the power quality of an energy storage converter. When the voltage state is abnormal, an impedance estimation method is used to estimate the impedance of the grid connection point line. A voltage control optimization algorithm is executed based on the obtained impedance information and voltage information to calculate the capacity for voltage control and perform voltage control. When the voltage state is normal or the converter has residual capacity for harmonic control after executing the voltage control optimization algorithm, the grid connection point line current is sampled, and its third and fifth harmonic amplitudes and phases are obtained through fast Fourier transform. After obtaining the effective value of the grid connection point voltage at the current moment, a harmonic control optimization algorithm is executed and harmonic control is performed. The strategy disclosed by the present invention improves the flexibility of power quality control of the energy storage converter and the capacity utilization rate of the energy storage converter.

The invention relates to the technical field of power grid harmonic suppression, in particular to a fundamental-loss-free low-parallel-resonance band-pass filter which comprises a first single-tuned filter Hn1 and a second single-tuned filter Hn2 which are arranged in parallel, and the series resonance frequencies of the first single-tuned filter Hn1 and the second single-tuned filter Hn2 are different. A group of resistors R1 is bridged between the first single-tuned filter Hn1 and the second single-tuned filter Hn2; the first single-tuned filter Hn1 comprises a first capacitor C11, a second capacitor C12 and a first reactor L1, the first capacitor C11, the second capacitor C12 and the first reactor L1 are connected in series, the second single-tuned filter Hn2 comprises a third capacitor C2 and a second reactor L2, and the third capacitor C2 and the second reactor L2 are connected in series; according to the invention, the structure is simple, the cost is low, the resistor R1 has no fundamental wave loss, the energy conversion efficiency of the whole power system is improved, the loss of energy in the transmission and treatment process is reduced, and the energy-saving effect is good.