39 results about "Harmonic filtering" patented technology

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 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 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.

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 utility model provides a wireless communication system of an intelligent meter. The wireless communication system comprises an antenna, a harmonic filtering module, a radio frequency front-end module, a conditioning and frequency selecting module, a transceiving modem and a main control module which are connected in sequence, the antenna is in wireless communication connection with handheld equipment; the conditioning and frequency-selecting module comprises a frequency-selecting chip and a signal conditioning unit; the signal conditioning unit comprises a first diode and a second diode which are reversely connected in parallel; the output end of the radio frequency front end module is connected with the input end of the frequency selection chip; the output end of the frequency-selecting chip is connected with the transceiving modem; the anode of the first diode is connected with the ground, and the cathode of the first diode is connected between the output end of the radio frequency front end module and the input end of the frequency selection chip. According to the utility model, the synchronization of wireless data transmission stability and transmission distance can be obviously improved, and the number of network transmission relay devices can be reduced.

The invention relates to the technical field of air compressor systems, and discloses an energy-saving air inlet system of an air compressor, which comprises the following modules: a traveling wave thermoacoustic refrigeration module for performing passive refrigeration on inlet air by using pressure pulsation energy in a main air inlet pipeline; the acoustic impedance matching and harmonic filtering coupling structure is used for optimizing sound energy transmission between modules and purifying driving sound waves; the self-adaptive Helmholtz resonance pressurization module is provided with variable geometric parameters and is used for realizing pulsating pressurization; and a cooperative control unit. And the cooperative control unit controls variable geometric parameters of the self-adaptive Helmholtz resonance pressurization module according to the real-time operation working condition of the compressor, so that the natural resonance frequency of the self-adaptive Helmholtz resonance pressurization module is dynamically matched with the fundamental frequency of air inlet pulsation. According to the air compressor, cooperative work of air inlet passive refrigeration and all-working-condition self-adaptive resonance pressurization is achieved, and the volume efficiency and the system energy efficiency of the air compressor are remarkably improved.

1. The name of the design product: heavy harmonic filter compensation reactor. 2. The use of the design product: used in industrial and civilian power distribution systems to achieve harmonic control, reactive compensation and comprehensive power quality control, and to improve the performance and stability of the power grid. 3. The design points of the design product: in shape. 4. The picture or photo that best shows the design points: perspective view 1.

The invention discloses a transformer comprehensive loss measurement system and method based on SF6 gas insulation and multi-range integration, and the system comprises a three-phase independent high-voltage measurement unit, a data collection unit, an AD conversion module, a signal preprocessing unit, a calculation module, a data caching unit, a communication interface, a data uploading and display unit, and a control host. The method comprises the following steps: firstly, collecting signals, then carrying out AD conversion, then carrying out harmonic filtering, and then carrying out a calculation process; then storing the data; and then the stored data is transmitted to the control host, and then real-time waveform display and report output are performed, so that the contradiction between wide range and high precision is fundamentally solved, field interference and overvoltage impact can be effectively resisted, and the test efficiency and the automation level are greatly improved. And the safety risk caused by manual operation in a high-voltage area is avoided.

Synchronizing the grid-side harmonic filter and pre-charged battery capacitors in a modular multilevel converter can be achieved by: disconnecting a transmission circuit breaker on a first path between the grid and the converter system; closing a pre-charge contactor on a second path between the grid and the converter system, the pre-charge contactor comprising a set of pre-charge resistors; connecting the grid to the converter system and harmonic filter via the second path; selectively charging the battery capacitors in the converter system until a charge threshold is reached, wherein a smaller subset of the battery capacitors is charged at a given time compared to an earlier time, and each battery capacitor is charged to a higher battery voltage compared to an earlier time; and closing the transmission circuit breaker, and simultaneously connecting the generator to the converter system via a generator circuit breaker while closing the pre-charge contactor.

The invention discloses a permanent magnet synchronous motor adaptive sliding mode observation method based on fuzzy logic and DSOGI-PLL, and belongs to the technical field of motor sensorless control. According to the method, aiming at the buffeting and phase lag problems of a traditional sliding mode observer, a fuzzy logic controller is adopted to dynamically adjust the sliding mode gain and the F (s) function slope coefficient, and the buffeting of the system is effectively inhibited; meanwhile, a double-second-order generalized integrator phase-locked loop is introduced to carry out orthogonal decomposition and harmonic filtering on the back electromotive force signal, a fundamental component is accurately extracted, and phase delay is reduced. The method is embedded into a permanent magnet synchronous motor vector control system and can replace a mechanical position sensor to realize high-precision rotation speed and position estimation. Simulation and experiment results show that the method has remarkable advantages in the aspects of buffeting suppression and counter electromotive force estimation precision.

The invention belongs to the technical field of short-wave radio stations, and relates to a heat dissipation structure for a high-power harmonic filter and an installation method of the heat dissipation structure. The heat dissipation structure comprises a plurality of heat dissipation grounding columns which are distributed between a harmonic filter mounting surface and a short-wave radio set casing; the harmonic filter mounting surface is an area which is arranged on the printed circuit board and is used for mounting and fixing the harmonic filter, and a ground network copper-clad area is arranged on one surface, close to the heat dissipation grounding columns, of the harmonic filter mounting surface and is used for realizing electrical connection with the plurality of heat dissipation grounding columns. According to the structural design of the heat dissipation grounding pole, the area of a printed circuit board of a harmonic filter is not increased while the heat dissipation efficiency is improved and the grounding resistance is reduced, and the design concept of miniaturization of airborne equipment is met.

The utility model discloses a balanced sense quantity three -phase LC harmonic filter reactor, including three magnetic core assemblies and three middle columns magnetic cores, three magnetic core assemblies are annular distribution, the magnetic core assembly includes upper cover magnetic core and lower cover magnetic core, and two adjacent magnetic core assemblies are connected through the middle column magnetic core, the top of middle column magnetic core is connected with the two upper cover magnetic cores of adjacent magnetic core assembly simultaneously, the bottom of middle column magnetic core is connected with the lower cover magnetic core of adjacent magnetic core assembly simultaneously, the coil is sheathed on the middle column magnetic core, and the upper cover magnetic core, lower cover magnetic core and middle column magnetic core are all metal magnetic powder core. This structure can make three -way inductance precision reach the difference within 3%, and each phase inductance has only one coil, avoids the processing difficulty that traditional coil needs 8 -shaped encircling, and three -phase coil turns are completely same, reduces the production link and spends a lot of working hours to adjust coil turns or pad air gap to satisfy inductance balance's technology, saves copper material consumption, reduces production cost.

The utility model relates to the technical field of electromagnetic interference (EMI) filtering, in particular to an EMI filtering optimization structure for a switching power supply. The EMI filter circuit is electrically connected with the input end of the rectifier bridge BD1, the output end of the rectifier bridge BD1 is electrically connected with the drive circuit through the filter module, the drive circuit is electrically connected with the primary side of the transformer T1, the dotted terminal of the secondary side of the transformer T1 is electrically connected with the anode of the diode D3, and the synonym terminal of the secondary side of the transformer T1 and the cathode of the capacitor EC3 are grounded. The cathode of the diode D3 is electrically connected with the anode of the capacitor EC3; the filtering module has a harmonic filtering function; the mounting position of the secondary side of the transformer T1 on the circuit board is far away from the EMI filter circuit; the problems that noise is introduced by subsequent harmonic filtering of the EMI filter circuit 1 and self EMI filtering fails due to improper layout of the circuit board are solved.

The invention provides a harmonic filter integrated in an ultra-short wave power amplifier in a matching manner by using a load traction technology, which comprises the following steps: setting different frequency points for a broadband power amplifier, and determining target impedance values corresponding to the different frequency points based on a preset test condition by combining the load traction technology; determining an input impedance network of the harmonic filter corresponding to the target impedance value according to the target impedance value, and matching an output transmission line corresponding to the input impedance network through impedance conversion by adopting a multi-order elliptical low-pass network model; an elliptical low-pass model is arranged in the harmonic filter, and a transmission zero point is generated through parallel resonance to suppress harmonic waves. According to the method disclosed by the invention, a module cascade matching joint debugging link can be omitted to the greatest extent, functional indexes of the module assembly are correspondingly improved, the volume space is saved, the integrated design is realized, the application, installation and operation are simple and convenient, and the performance is stable and reliable.

The invention relates to the technical field of electronic power, in particular to a box-type substation overload monitoring device and method, and the method comprises the steps: connecting a harmonic filter and an energy storage power supply into a box-type substation, carrying out the dynamic control of the harmonic filter and the energy storage power supply, and achieving the overload monitoring, and performing energy storage power supply control according to the suppression capability of the harmonic filter on each harmonic frequency and a preset overload correction coefficient. When overload is detected again, the overload correction coefficient is updated according to the overload quantity obtained by the harmonic filter and the energy storage power supply in the historical working process and the suppression capability of each harmonic frequency, so that the difference between the residual quantity of the energy storage power supply and the output quantity of the energy storage power supply is maximum; and then controlling the energy storage power supply based on the updated overload correction coefficient. According to the overload monitoring device, the accuracy of active overload monitoring of the box-type substation can be improved.

The invention relates to the technical field of filter structure design, and discloses a passive harmonic filter based on a common iron core structure and a design method and system thereof, the method can configure filter parameters based on a basic magnetic circuit structure of the filter, and specifically, the inductance value of the basic magnetic circuit structure is determined according to application parameter information of the filter; according to the basic magnetic circuit structure, the inductance value and the number of turns of a main loop reactor coil in the basic magnetic circuit structure, determining the number of turns of a filter branch reactor coil in the basic magnetic circuit structure; determining air gap configuration parameters according to the basic magnetic circuit structure, the number of turns of the main loop reactor coil and the number of turns of the filter branch reactor coil; and determining a final structure result of the filter according to the information. Therefore, the comprehensiveness and rationality of the structural design mode of the passive harmonic filter can be improved, and the accuracy, pertinence and fitness of the final structural result of the filter are improved.

This invention discloses a generator shaft current harmonic filtering and shaft voltage precise suppression device, belonging to the technical field of generator protection devices. During generator operation, the device, through the cooperation of a detection module, filtering module, active compensation module, control module, and discharge component, precisely offsets shaft voltage fluctuations on the shaft. Simultaneously, the grounding brush on the discharge component provides a low-resistance grounding path for the shaft, discharging residual shaft voltage and harmonic current, stabilizing the shaft potential within a safe range. Furthermore, during grounding brush operation, the cooperation of a pressure component, elastic component, drive component, and linkage component maintains a relatively stable compressive force on the grounding brush during wear, ensuring good contact between the grounding brush and the shaft, further guaranteeing the normal discharge of shaft voltage, shaft current, and high-frequency harmonic current to the ground.

The invention provides a micro-grid energy-saving system, and relates to the technical field of power system energy saving. The system comprises an electromagnetic balance treatment device which realizes three-phase current balance adjustment, reactive power dynamic compensation and harmonic filtering through an electromagnetic induction principle; the intelligent control unit comprises a multifunctional electric power meter, a temperature sensor and a central processing unit, and is used for collecting electrical parameters and temperature data in real time and automatically adjusting the running state of the system according to a preset algorithm; the Internet of Things monitoring platform is connected with the intelligent control unit in a wireless communication mode to realize remote monitoring and data uploading; and the micro-grid cooperation interface is used for performing power interaction with the distributed energy power generation equipment and the energy storage device. Power quality treatment is realized through a pure electromagnetic structure, the problems of complexity and potential harmonic waves of power electronic devices are avoided, comprehensive perception and accurate adjustment of the power grid state are realized by combining intelligent control and the Internet of Things technology, the system efficiency is remarkably improved, and the equipment loss is reduced.

The embodiment of the present disclosure provides an adaptive tracking tunable harmonic rejection amplifier, which is applied to the technical field of electronic circuits; the amplifier comprises an input port, a first amplifier, a harmonic filter, a second amplifier, a coupling capacitor, a feedback module, an output port closed loop architecture, the input port receives an external input signal, the first amplifier performs preliminary amplification, then the harmonic filter performs harmonic suppression, and the second amplifier performs re-amplification and then outputs, the feedback module generates a control signal according to the output signal, so as to adjust the parameters of the control end of the harmonic filter, and realize wideband harmonic suppression of the signal; through low gain fluctuation, the stability of signal amplification is ensured; through the feedback module, the harmonic component is detected in real time and the filtering parameter is regulated and controlled, dynamic tracking suppression of the harmonic is realized, manual intervention is not needed, and signal transmission loss and chip layout occupation area are greatly reduced.

This application discloses a modular multilevel DC / DC converter and its application system. The scheme includes an M-phase upper bridge arm, an M-phase lower bridge arm, an M-phase harmonic filtering module, and a controller. The m-phase upper bridge arm is connected to both the m-phase lower bridge arm and the m-phase harmonic filtering module. The m-phase harmonic filtering module is composed of a first inductor and N full-bridge sub-modules connected in series. The N full-bridge sub-modules in the m-phase harmonic filtering module filter out harmonic components from their own output current and, under the control of the controller, output a second DC voltage component and the fundamental frequency component of the second AC voltage component. The sum of the fundamental frequency components in all second AC voltage components is 0. Therefore, this scheme extracts the second DC voltage component generated by the lower bridge arm through the harmonic filtering module composed of full-bridge sub-modules, thereby achieving DC voltage conversion, replacing the function of a passive large inductor, and reducing footprint and energy loss.

The application provides a signal conversion system and method, and relates to the technical field of signal modulation.The signal conversion system comprises a diplexer, a receiving filter, a mixer, and a transmitting filter, wherein the transmitting filter comprises a harmonic filter; a receiving end of the diplexer, an input end of the receiving filter, an output end of the receiving filter, and an input end of the mixer are sequentially connected to form a signal receiving link; an output end of the mixer, an input end of the harmonic filter, an output end of the harmonic filter, and a transmitting end of the diplexer are sequentially connected to form a signal transmitting link; the signal receiving link extracts an input signal of an initial frequency, and transmits the input signal to the mixer; the mixer generates a difference frequency signal; the signal transmitting link extracts an output signal of a target frequency from the difference frequency signal, suppresses harmonic interference of the output signal, and feeds the output signal into the diplexer.The application at least solves the problem that it is difficult to simultaneously guarantee high isolation, signal purity, and reliability in the prior art.The application is suitable for a signal conversion scene.

This invention provides a high-efficiency, low-temperature-rise passive harmonic filter, belonging to the field of filters. It includes a main base housing and a top housing with evenly spaced heat dissipation side slots on both sides, which work in conjunction with symmetrically fixed cooling fans on the inner side to form an effective airflow channel. The cooling fans draw external cool air into the top housing, accelerating airflow and allowing heat to be quickly dissipated to the external environment, significantly improving heat dissipation efficiency. The evenly fixed heat dissipation side plates on the outer side of the passive harmonic filter further increase the heat dissipation area, while the porous structure of the perforated support plate also facilitates airflow and enhances the heat dissipation effect. Through these heat dissipation designs, the temperature rise of the filter during operation is effectively reduced, ensuring that the internal electronic components operate in a suitable temperature environment, improving component performance and lifespan, reducing the failure rate caused by overheating, and improving the reliability and stability of the filter.

This invention discloses a harmonic-suppressible solid-state transformer, relating to the field of transformer technology. It includes a main housing, an upper conductive partition, a lower conductive partition, a power conversion assembly, a high-frequency transformer assembly, and a harmonic filtering component. The upper and lower conductive partitions divide the main housing into three independent chambers. During operation, the power conversion assembly first performs high-frequency power conversion, followed by voltage transformation and transmission by the high-frequency transformer assembly. Finally, the harmonic filtering component filters out current noise and outputs clean electrical energy. During this process, the electromagnetic radiation and leakage magnetic field harmonics generated by each component are blocked by the physical barriers constructed by the upper and lower conductive partitions. This invention filters harmonics and electromagnetic noise in the current through the harmonic filtering component, thus avoiding harmonic crosstalk.

The utility model discloses a C wave band low harmonic power amplifier relates to the field of amplifier, and the amplifier includes the phase -locked loop frequency source module, and its output is connected pre -inhibit harmonic filter, adjustable gain forestage amplifier, interstage dynamic harmonic suppression module and double power divider microstrip circuit in proper order. Two output ends of double power divider microstrip circuit are connected first, second final stage power amplifier respectively, and its output is synthesized through double -way power synthesizer microstrip circuit again, and finally by radio frequency port output, while access feedback detection module, under the control of control module, through interstage dynamic harmonic suppression module to harmonic real -time regulation and control, combine the closed -loop feedback mechanism of feedback detection module, and the harmonic distortion caused by temperature drift, device aging is effectively suppressed, and the stability of harmonic suppression performance is significantly improved while guaranteeing high -power output.

The application discloses an SVF harmonic filtering method based on current harmonic component rapid analysis, which comprises the following steps: extracting three-phase currents and capacitor voltages from a line commutated converter (LCC) and a static var generator (SVF); performing park transformation on the extracted three-phase currents in the LCC to obtain a steady-state reactive reference quantity; performing park transformation and moving average filtering on the extracted three-phase currents in the SVF to extract a control quantity; comparing the error of the capacitor voltages to establish an active and reactive current control loop; performing inverse park transformation on the output signals of the active and reactive current control loop to obtain a fundamental current component, then processing the harmonic components after the park transformation by adopting a degree locking Fourier extractor, extracting a reference quantity from the LCC, taking the current of the SVF itself as a control quantity, performing inverse park transformation on the processed harmonic components, and superimposing and outputting the harmonic components and the fundamental current component. The method realizes rapid identification and accurate suppression of specific harmonic, and improves high-frequency response speed and steady-state performance.

The application discloses a radio frequency harmonic filtering circuit and electronic equipment, and relates to the technical field of radio frequency harmonic filtering circuits, and aims to provide a radio frequency harmonic filtering circuit and electronic equipment.

This application provides a radio frequency (RF) device and its inductor. The RF device includes a power amplifier circuit, a signal coupling circuit, an extraction circuit, and a harmonic filter circuit. The power amplifier circuit amplifies a differential signal to output a signal to be filtered. The signal coupling circuit includes a primary inductor and a secondary inductor. The signal coupling circuit receives the signal to be filtered through the primary inductor and outputs a single-ended signal from the secondary inductor. The extraction circuit has a center tap. The extraction circuit couples with the primary inductor and outputs a common-mode signal from the center tap. The harmonic filter circuit performs harmonic filtering on the single-ended signal based on the common-mode signal, so that the secondary inductor of the signal coupling circuit outputs a filtered signal.

The application relates to the technical field of filter structure design, and discloses a passive harmonic filter based on a common iron core structure and a design method and system thereof, which can configure filter parameters based on a basic magnetic circuit structure of the filter, specifically, determining an inductance value of the basic magnetic circuit structure according to application parameter information of the filter; determining the number of turns of a filter branch reactor coil in the basic magnetic circuit structure according to the basic magnetic circuit structure, the inductance value and the number of turns of a main loop reactor coil in the basic magnetic circuit structure; determining air gap configuration parameters according to the basic magnetic circuit structure, the number of turns of the main loop reactor coil and the number of turns of the filter branch reactor coil; and determining a final structure result of the filter according to the foregoing information. It can be seen that the application can improve the comprehensiveness and rationality of the passive harmonic filter structure design method, and improve the accuracy, pertinence and fitting of the final structure result of the filter.

The invention discloses a power distribution network electric energy quality integrated management device based on four-quadrant adjustable impedance and a control method, and belongs to the technical field of electric energy quality integrated management. The functions of harmonic filtering, reactive compensation and imbalance treatment are realized at the same time through adaptive topology switching; the power quality monitoring module is used for collecting parameters of a power grid in real time. The coupling mechanism analysis module is used for outputting a dynamic weight coefficient of each governance target; the four-quadrant impedance regulation and control module supports continuous regulation of resistive, inductive, capacitive and composite characteristics according to an output result of the coupling mechanism analysis module; the cooperative control module comprises a model prediction control unit, a dynamic weight distribution unit and a protection logic unit; the communication interface unit supports remote parameter setting and energy efficiency optimization. According to the invention, based on a dynamic reconstruction technology of four-quadrant adjustable impedance, integrated unified control of harmonic suppression, reactive compensation and three-phase imbalance treatment is realized.