125 results about "Harmonic filtering" patented technology

The invention provides a weak signal multi-module networking self-adaptive monitoring system for power transmission and transformation construction, and relates to the technical field of multi-module networking, and the system comprises a multi-mode module which is used for deploying a multi-mode sensing unit at a key monitoring point of power transmission and transformation equipment, collecting vibration, partial discharge, leakage current and environmental parameter signals, and transmitting the signals to a monitoring center; the signals are processed through packaging of an electromagnetic shielding shell and a built-in harmonic filter circuit so as to obtain original monitoring signal data; and the detection module is used for inputting the original monitoring signal data into the chaotic enhanced weak signal detection device, and extracting a fault feature vector by capturing an attractor phase diagram abrupt change and a time domain waveform threshold. Through the multi-mode sensing and self-adaptive networking technology, monitoring of power transmission and transformation weak signals and timely extraction of fault features are achieved, and the fault early warning accuracy and the self-adaptive capacity are improved.

The invention provides a split type direct current charging multi-split group charging and group control control system, and belongs to the technical field of split type direct current charging piles. The split type direct current charging system comprising a main control cabinet, a power distribution unit, a charging pile terminal and other hardware architectures is constructed; a voltage monitoring unit, a current sensor module, a harmonic filter and other multi-dimensional sensor networks are integrated to acquire power grid state data in real time, and a sliding time window method is used to carry out segmented analysis on the data to extract power grid characteristic parameters; establishing a multi-objective optimization model comprising a power balance equation and a power grid stability equation to calculate an optimal power distribution matrix, adopting a neural network to realize intelligent distribution and dynamic balance adjustment of the power of each charging pile terminal, and starting an emergency power redistribution mechanism to ensure stable operation of the system when the power grid is detected to be abnormal. The technical problem of unbalanced power distribution of the multi-pile charging system caused by power grid voltage fluctuation and harmonic pollution is solved.

The invention relates to a radial frequency-doubled sound filtering metamaterial and a topological optimization design method thereof.The radial frequency-doubled sound filtering metamaterial comprises scatterers which are arranged on a base body and distributed in a concentric circle mode, and the topological optimization design method comprises the following steps that a two-dimensional axial symmetry model is established, the two-dimensional axisymmetric model corresponds to the cross section of the radial frequency-doubled sound filtering metamaterial in the radius direction and comprises periodically arranged unit structures, and each unit structure comprises a main board and a square design domain; a Floquet periodic boundary condition is applied to parallel boundaries of a unit structure in the radius direction, other boundaries are set as free boundaries, a genetic algorithm is adopted to carry out iterative optimization on the material distribution topology of a square design domain, the optimal material distribution topology of the square design domain is obtained, and then the final optimized shape of the radial double-frequency sound filtering metamaterial is obtained. Compared with the prior art, the invention has the advantages of capability of realizing omni-directional sound wave frequency doubling filtering, high design reliability and the like.

The invention discloses a dynamic harmonic filtering control method and system, and relates to the technical field of electric power, and the method comprises the steps: collecting a voltage signal and a current signal of a power grid in real time; performing spectral analysis on the collected signals, and extracting harmonic characteristics; based on the harmonic characteristics, generating a compensation signal and optimizing the compensation signal; dynamically adjusting filtering parameters, and injecting an optimized compensation signal into a power grid through a filter module; uploading a system operation state in real time, and detecting and marking an abnormal state; according to the invention, rapid response and efficient suppression of power grid harmonics can be realized, the adaptability and filtering precision of multi-band harmonics are significantly improved, and the total distortion rate of the harmonics is greatly reduced, so that the quality of electric energy is optimized. The system operation efficiency and stability are improved, the anti-interference capability is strong, and the system is suitable for a complex power grid environment; the system can monitor the operation state in real time, automatically give an alarm and mark abnormity, the reliability and safety of power grid operation are improved, and the maintenance cost is reduced.

The present invention discloses a low-voltage harmonic filter module, which relates to the technical field of circuit devices. This low-voltage harmonic filter module includes a filter body and a base, a plurality of shock-absorbing mechanisms are arranged between the filter body and the base, and each shock-absorbing mechanism includes an L-shaped plate, a first mounting mechanism is arranged between the bottom of each L-shaped plate and the base, and the side wall of each L-shaped plate is fixedly connected with a connecting plate, the side wall of the connecting plate is fixedly connected with an annular cover, and a moving column is inserted in the annular cover, a rubber ring is fixedly connected between the moving column and the annular cover, and a first spring is fixedly connected between the moving column and the bottom of the annular cover, and a second mounting mechanism is arranged between the moving column and the filter body. This low-voltage harmonic filter module can have a good shock-absorbing effect on the filter body, ensure its filtering effect and service life, and at the same time, it can consume the energy generated by the vibration, so that the shock-absorbing effect is better.

A voltage synchronizing signal detection method based on an improved DSOGI-PLL is characterized in that a DSOGI-QSG algorithm is adopted in a phase-locked loop, a difference node is introduced on a second-order generalized integrator SOGI structure in the DSOGI-QSG to improve the DSOGI structure, and the improved DSOGI-QSG structure is obtained and can suppress the influence of a direct current component on extraction of each parameter; a specific subharmonic elimination module structure is additionally arranged at the front end of the SOGI structure to serve as a front harmonic filtering cascade module, then the amplitude is corrected through a correction coefficient, and finally filtered signals are input into the SRF-PLL. A cascade harmonic elimination module is constructed in front of the QSG to suppress the distortion harmonic influence, and meanwhile, the QSG structure is optimized, so that the QSG structure can eliminate the direct current amount in the signal, the good characteristics of the traditional DSOGI-PLL are reserved, and meanwhile, the influence of the current bias amount, harmonic distortion and three-phase imbalance of the power grid synchronization signal on the phase locking speed and accuracy can be effectively reduced; and the system performance and applicability are improved.

The invention relates to a double-frequency filtering metasurface design method based on topological optimization. The method comprises the following steps: establishing a two-dimensional simulation model comprising a double-frequency filtering metasurface matrix and a scatterer; according to a preset target forbidden band, taking a forbidden band frequency covering frequency doubling target interval as a fitness function, coding the binary matrix representing material distribution as a chromosome to perform optimization iteration of the chromosome, and obtaining the chromosome with the maximum fitness function value; in optimization iteration, material distribution corresponding to chromosomes is constructed on a two-dimensional simulation model, an energy band structure of the two-dimensional simulation model is obtained, and a fitness function value is calculated; and according to the binary matrix of the chromosome with the maximum fitness function value, outputting final optimized material distribution of the double-frequency filtering metasurface, and performing performance verification on a result through simulation to obtain the double-frequency filtering metasurface of which a fundamental frequency wave can be blocked through a double-frequency wave. Compared with the prior art, systematic optimization of the frequency doubled sound filtering scene is realized.

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 transformer fault diagnosis method, system and equipment based on harmonic injection and a storage medium, and the method comprises the steps: installing a vibration sensor on a transformer body, collecting steady-state and dynamic vibration signals, and carrying out the preprocessing of the vibration signals; time domain feature analysis is carried out on the collected vibration signals, frequency domain feature analysis is carried out on the vibration signals, and then spectrum complexity is analyzed; normal ranges of RMS values, peak factors and odd-even harmonic ratios are set through historical data, and if the data exceed the set ranges, the fan influence is further analyzed; analyzing in combination with a power system operation mode, and then performing fault judgment based on a machine learning classification algorithm; if the direct current magnetic bias is detected, an HVDC operation mode is adjusted; and if harmonic injection is detected, an active harmonic filter is adopted to suppress harmonic interference. The harmonic current is detected and compensated in real time, the voltage and current waveforms of the power grid are improved, the harmonic pollution of the power grid is reduced, and the electric energy quality is improved.

The invention provides a fundamental frequency calculation method for adaptive parameter adjustment, which is suitable for power signal frequency estimation under a noise interference or multi-harmonic background. Firstly, voltage and current signals are subjected to analog-to-digital conversion to obtain digital signals, a CIC filter in a non-recursive form is adopted for multi-stage extraction processing, and the data complexity is reduced; sequentially inputting the extracted signals into a plurality of notch filters with feedback structures for harmonic filtering; and iteratively updating the center frequency parameter of the notch filter through a gradient descent method, and when the error function is minimized, the current frequency parameter is the fundamental frequency of the signal. The method has the characteristics of fast convergence, strong robustness and high calculation precision, and is suitable for scenes of electric energy metering, frequency protection and the like.

The utility model discloses an energy taking circuit of a contact network fault monitoring device and a monitoring device, and the energy taking circuit comprises a first harmonic filtering module which is used for obtaining a DC signal from the circuit and carrying out harmonic filtering processing; the inversion module is electrically connected with the first harmonic filtering module, and the inversion module receives the electric signal processed by the first harmonic filtering module and inverts the electric signal; the first rectification module is electrically connected with the inversion module, and the first rectification module receives the alternating current signal of the inversion module and converts the alternating current signal into a direct current signal; and the second harmonic filtering module is electrically connected with the first rectification module and is used for carrying out harmonic filtering processing on the direct current signal processed by the rectification module and then supplying power to the monitoring device. The energy taking circuit can solve the technical problem that harmonic components caused by a non-linear load in the circuit are difficult to be eliminated by a simple harmonic filtering circuit, and provides stable power supply for a terminal.

The three-phase LC harmonic filter reactor comprises three magnetic core assemblies, the three magnetic core assemblies are annularly distributed, each magnetic core assembly comprises an upper cover magnetic core, a lower cover magnetic core and two center pillar magnetic cores, the top ends of the two center pillar magnetic cores are connected with the two ends of the upper cover magnetic core respectively, and the top ends of the two center pillar magnetic cores are connected with the two ends of the lower cover magnetic core respectively. The upper cover magnetic core and the lower cover magnetic core are arranged in the two magnetic core assemblies, the bottom ends of the two middle column magnetic cores are connected with the two ends of the lower cover magnetic core respectively, in the two magnetic core assemblies, every two adjacent middle column magnetic cores form a middle column magnetic core set, the middle column magnetic core sets are sleeved with coils, and the upper cover magnetic core, the lower cover magnetic core and the middle column magnetic cores are all metal magnetic powder cores. According to the structure, the precision of three paths of inductance values can reach the difference within 3%, meanwhile, each phase of inductance has only one coil, the processing difficulty that a traditional coil needs 8-shaped winding is avoided, the number of turns of the three-phase coils is completely the same, the process that a large amount of working hours are spent on adjusting the number of turns of the coils or padding air gaps to meet inductance balance in the production link is reduced, and the production efficiency is improved. Copper material consumption is saved, and production cost is reduced.

A system includes a voltage-controlled oscillator (VCO), a first second-order harmonic filter coupled to the VCO, wherein the first second-order harmonic filter includes a first tunable capacitor, and a second second-order harmonic filter coupled to the VCO, wherein the second second-order harmonic filter includes a second tunable capacitor. The system also includes a measurement circuit coupled to the VCO, wherein the measurement circuit is configured to measure a voltage swing of the VCO. The system also includes a control circuit coupled to the measurement circuit, the first tunable capacitor, and the second tunable capacitor.

The invention provides a filter circuit, a filter control device and a filter control method. The filter circuit comprises a first inductor device, a first capacitor device and a plurality of filter branches; the first end of the first capacitor device is used for connecting a stator of the generator and the first end of the first inductor device, and the second end of the first capacitor device is connected with the plurality of filter branches; the plurality of filtering branches are connected in parallel; the second end of the first inductor device is connected with the double-fed converter; at least part of the filtering branches comprise resonance parameter adjusting devices, and the resonance parameter adjusting devices in different filtering branches are different; the filtering branch also comprises an on-off control device which is used for controlling the on-off of the filtering branch and the first inductance device. According to the mode, different resonance parameter adjusting devices can be communicated, so that frequency band harmonic waves existing in a current loop are filtered out, the harmonic waves of all frequency bands can be effectively filtered out by connecting the different resonance parameter adjusting devices, a wide-frequency-band filtering function is achieved, and the harmonic wave filtering effect of all the frequency bands is improved.

The application relates to a high-voltage power-taking capacitor protection and harmonic suppression system and a circuit thereof, and belongs to the field of power distribution network intelligent control switch power taking. The circuit is arranged between an isolation transformer and a feeder terminal unit (FTU), and comprises an input protection circuit for suppressing input surge overvoltage and fast pulse group, a harmonic filter circuit for filtering out harmonics, a signal acquisition and conditioning circuit for converting an alternating current signal into a direct current voltage signal, and a control protection circuit for comparing the direct current voltage signal with a preset reference voltage. The system further comprises a high-voltage capacitor voltage divider, an isolation transformer and the feeder terminal unit (FTU). The application effectively solves the problem that harmonic interference, surge impact and overvoltage risk coexist in the high-voltage power-taking system, greatly improves the safety and reliability of the operation of the rear-end FTU equipment under the premise of ensuring the accuracy of voltage signal measurement and power supply continuity.

The application relates to the technical field of harmonic filters, in particular to a harmonic filter for power quality improvement, which comprises a harmonic filter body, and first and second sealing connection plates are respectively fixedly connected to both ends of an outer frame cover in the harmonic filter body through bolts. Two first and second sliding outer frames which are uniformly arranged in the harmonic filter body can be slid out of the inner part of the outer frame cover after the first sealing connection plate is removed according to the needs of maintenance, installation and disassembly, an electric push rod which is uniformly arranged on the second sliding outer frame is started to control the forward movement of a connection plug which is inserted into the inner part of a butt joint connection column, no matter whether a driving control gear is arranged on a sliding driving gear plate on the first or second sliding outer frame, as long as the electric motor drives the driving control gear to rotate and operate, the first or second sliding outer frame is synchronously slid outwards.

The utility model relates to the field of harmonic filtering devices, in particular to a harmonic filtering device of a high-voltage frequency converter. Comprising a frame, a control interface is arranged on the surface of the frame, a plurality of filter modules are installed in the frame, an adjusting structure is arranged at the position, corresponding to the filter modules, of one side of the inner wall of the frame, the adjusting structure comprises a plurality of fixing plates, the fixing plates are fixedly connected with the frame, and supporting frames are fixedly connected to the surfaces of the fixing plates; the side, away from the fixing plate, of the supporting frame is rotationally connected with a connecting block, the side, away from the supporting frame, of the connecting block is fixedly connected with a supporting plate, and the side, close to the supporting frame, of the fixing plate is fixedly connected with a magnetic block. The harmonic filtering device of the high-voltage frequency converter provided by the utility model has the advantages that the supporting plate can be conveniently stored and unfolded, the supporting plate and the pressing plate are used for bunching and arranging a plurality of connecting wires on the filter module, the time for subsequently arranging the connecting wires is shortened, the working efficiency of maintenance operation is improved, and the practicability is high.

Embodiments pertain to methods and system for detecting and / or characterizing at least one object in a scene that is being propelled by at least one rotating device. The methods may include transmitting electromagnetic radiation (EM) into free space towards the scene; receiving, from the scene, EM radiation reflections that are reflected from at least one rotating device of the at least one object that is present in the scene; and processing the reflections to detect, based on harmonic characteristics of the reflected EM radiation, the presence of the at least one object in the scene. In some examples, the methods include processing the reflections to characterize, based on the harmonic characteristics of the reflected EM radiation, the type of the at least one detected object. In some examples, the processing comprises applying an harmonic filter on the reflected EM radiation to detect harmonics of the reflected EM radiation.

Various embodiments of the present disclosure provide a neutral and / or ground harmonic filter system for mitigating neutral and / or ground harmonics.

The invention belongs to the field of intelligent power distribution systems, and provides a design method and system for an online harmonic monitoring system of a power system, and the method comprises the following steps: collecting a voltage signal of a transformer in a transformer substation in real time through a voltage transformer; performing frequency domain analysis on the acquired voltage signal by applying Fourier transform, and extracting each frequency component in the signal; setting a time window and a time interval, obtaining the frequency corresponding to the frequency component with the maximum amplitude in each time interval, and recording the frequency as the highest frequency; obtaining a harmonic super-harmonic frequency difference through the highest frequency, and obtaining a harmonic violent wave band time window through the harmonic super-harmonic frequency difference; and obtaining a harmonic violent band ratio through the harmonic violent band time window, and monitoring the operation condition of the power system through the harmonic violent band ratio. According to the design method provided by the embodiment of the invention, the problem can be quickly detected at the initial stage of harmonic pollution, and the harmonic filter is timely started or the load distribution is adjusted, so that the stability of the power system is ensured.

An amplifier includes a signal input terminal for inputting an input signal; a voltage input terminal for inputting a power supply voltage; an amplification circuit for generating an amplified input signal based on the input signal, wherein the amplified input signal has a fundamental frequency, a first harmonic, and a second harmonic, wherein the first harmonic is the second harmonic of the fundamental frequency, and the second harmonic is the third harmonic of the fundamental frequency; a harmonic filter circuit coupled between the voltage input terminal and the amplification circuit for filtering the first harmonic and the second harmonic; and a signal output terminal coupled to the harmonic filter circuit for outputting an output signal based on the amplified input signal.

This invention discloses a specific harmonic cancellation pulse width modulation method suitable for digital power amplifiers. It involves fitting a periodic signal f(t) to obtain an approximate function g(t) and performing Fourier analysis to derive the Fourier coefficients b of the current. n Wherein, the Fourier coefficient b n With the switching angle sequence α q 'As a parameter; for the switching angle sequence α q 'Optimization is performed to obtain the optimized switching angle sequence α' q According to α q The corresponding circuit is controlled by pulse width modulation to output a voltage waveform with specific harmonics filtered out. This invention obtains a specific switching angle sequence by establishing and solving a system of nonlinear equations. The output voltage waveform with specific harmonics filtered out is then modulated based on this switching angle sequence. This method can generate the desired frequency domain component and eliminate unwanted harmonics. It is also applicable to the design of multiple H-bridge units. At the same switching frequency, this method can output higher-order harmonics than other modulation methods, thus reducing switching losses. Furthermore, its excellent harmonic suppression performance saves hardware costs.

The present invention discloses a method and device for processing ultra-high power microwave spectrum, including: after filtering the original ultra-high power microwave signal for high-order harmonics and absorbing the harmonic reflection, the ultra-high power microwave signal after filtering is distributed with equal power to obtain multiple first microwave signals with equal amplitude and the same phase to reduce the harmonic output level, and then each first microwave signal is successively subjected to reflection module filtering, band-stop filtering, and band-pass filtering to suppress the receiving band spectrum to obtain multiple microwave signals after receiving band processing, and then each receiving band processed microwave signal is subjected to power synthesis to obtain an ultra-high power microwave signal after spectrum processing, and finally sent to an antenna or a load by a high directional coupler. The present invention realizes the integration of ultra-high power microwave filtering network, realizes the spectrum processing capability under ultra-high power conditions, and improves the ultra-high power spectrum processing technology level of my country in the field of deep space exploration.

The invention relates to the field of current reducing systems, and particularly discloses a system and a method for reducing current and improving electric energy quality, comprising at least one current limiting module, a first current transformer, at least one capacitive module, a first switch, a second switch, a third switch, a fourth switch, a control protection system and a voltage transformer, the current limiting module is connected in series with the third switch, then connected in parallel with the fourth switch, and then integrally connected in series with the first current transformer; the capacitive module is connected in series with the second switch and then connected in parallel with the third switch; one end of the first switch is connected with the capacitive module and a connecting line of the second switch, and the other end of the first switch is grounded. Functions of current limiting, reactive compensation, series compensation, harmonic filtering and the like can be realized, and the number of equipment is reduced.

The invention discloses a capacitance setting method and device for a filter and a storage medium, and the method comprises the steps: calculating a working current flowing through a single-tuned filter under the condition that a harmonic wave is injected into the single-tuned filter; the single tuned filter comprises a capacitor and a reactor; calculating the rated capacity of the capacitor according to the working current; according to the rated capacity of the capacitor, calculating the rated voltage which can filter harmonic waves and is minimum in capacity for the capacitor; and setting the minimum capacity of the capacitor according to the rated voltage of the capacitor. According to the embodiment of the invention, the minimum capacity of the capacitor is calculated under the condition of keeping the harmonic filtering effect of the capacitor of the single-tuned filter, and the cost of the capacitor can be reduced, so that the cost of the single-tuned filter is reduced, and the cost is reduced on a large scale when a large number of low single-tuned filters are deployed in a power distribution network.

The utility model belongs to the technical field of power equipment, and provides a frequency converter which comprises a frequency converter unit mechanism, a passive low-harmonic filtering mechanism and a sine filtering mechanism, the frequency converter unit mechanism comprises a frequency converter machine core, and the frequency converter machine core is connected with a direct-current reactor. The direct-current reactor is used for reducing main loop harmonic waves on the frequency converter machine core; the passive low-harmonic filtering mechanism comprises a three-phase input reactor and a three-phase filter reactor, the three-phase input reactor is electrically connected with external equipment, the three-phase filter reactor and the frequency converter machine core, and the three-phase filter reactor is used for reducing harmonic waves on an input line of the frequency converter; the sine wave filtering mechanism comprises a sine wave filter reactor used for reducing harmonic waves on an output line of the frequency converter, and the sine wave filter reactor is electrically connected with the frequency converter machine core and external equipment. Under the condition that the original specification is not changed, the technical problem that the harmonic wave of the frequency converter is too large is solved.

Embodiments herein relate to a clock distribution network. In one aspect, the network includes a resonant transmission line-based architecture which includes a single inductive-capacitance (LC) termination along the distribution and an additional capacitive termination at the end of the distribution to independently tune the primary and secondary resonance frequencies of the network and perform 3rd-harmonic filtering. The LC termination can include a coil inductor or a short-circuited termination line with parallel conductors to provide an inductance.

The utility model discloses a 30MHz-680MHz high-suppression harmonic filter, which comprises a shell, a box cover and a simulation PCB (printed circuit board), a filter circuit and a radio frequency switch circuit are arranged on the simulation PCB, a switch of the radio frequency switch circuit is annularly arranged, the shell is provided with a partition plate to divide the shell into an upper cavity and a lower cavity, the simulation PCB is fixedly connected in the upper cavity, and the box cover is fixedly connected in the lower cavity. The digital PCB is fixedly connected in the lower cavity, the two box covers respectively cover two ends of an upper opening and a lower opening of the shell, the front end of the shell is provided with a connector connected to the digital PCB, the connector serves as a control end of the harmonic filter, and the rear side of the shell is provided with an input end and an output end which are connected to the analog PCB. The annular layout switch is changed to the starting position of each section and the longitudinal layout, and the left and right side layouts are symmetrical, so that the influence of parasitic capacitance is eliminated, the length of the PCB can be greatly reduced, and the total length of the product is greatly reduced.

The invention discloses a method for measuring insertion loss of a harmonic filter. Measurement is carried out under the condition of rated voltage and rated current of a 50Hz / 400Hz power grid actually used by the harmonic filter, the method is simple, operation is convenient, and data are real and visual. Meanwhile, high-end equipment such as a network analyzer and a measurement receiver is not needed, and the measurement system is low in cost and reliable in operation. According to the method disclosed by the invention, the acquired analog data is transmitted after A / D conversion, so that the measured data is real and reliable and is prevented from being interfered by an electromagnetic environment. Finally, data processing is completed by means of existing mature software, a measured result is displayed in a frequency spectrum graph, the system is stable, new software does not need to be developed, time and money are saved, and efficiency is high.

The utility model provides a receiving and transmitting circuit of a 5G signal monitor. The receiving and transmitting circuit comprises a receiving and transmitting port, a receiving link, a transmitting link, a switching module and a frequency conversion module, the receiving and transmitting port is coupled to the receiving link and the transmitting link through the switching module, and the receiving link and the transmitting link are coupled to the frequency conversion module. The frequency conversion module is used for receiving the radio frequency signal transmitted by the receiving link and performing down-conversion processing or performing up-conversion processing on an analog baseband signal and then transmitting the processed signal to the transmitting link; the receiving link comprises a low-noise amplifier, a low-noise bypass amplifier and a gain amplifier which are connected in sequence, and the low-noise amplifier is in coupling connection with the switching module; the transmitting link comprises a driving amplifier, a power amplifier and a harmonic filter which are connected in sequence; and the harmonic filter is coupled with the switching module. According to the scheme, a direct frequency conversion structure is adopted, and the scheme cost and the total power consumption of the transceiver are reduced.