273 results about "Active filter" patented technology

The invention provides an intelligent harmonic dynamic compensation method and system for a data center. According to the method, server heat source surface temperature field distribution is monitored in real time through a distributed optical fiber temperature measurement array, and a dynamic impedance spectrum is generated; when the temperature gradient exceeds the flash evaporation critical value of the fluorinated cooling liquid, an active filter is activated to carry out dynamic impedance matching compensation on high-frequency harmonic current in the liquid cooling tank cabinet, and a pulse width modulation control signal of a circulating pump is generated; the compensation power of the filter and the turbulence intensity of the cooling liquid are synchronously adjusted by analyzing the coupling relation between the flowing vortex intensity of the cooling liquid and the dielectric polarization loss; when phase mismatch of a temperature field is caused by heat dissipation of multiple heat sources, a multi-band compensation strategy is reconstructed by utilizing frequency domain characteristics of a pulse width modulation signal and a compensation power historical value, and a cooling liquid branch flow distribution ratio and a filter frequency response curve are cooperatively adjusted. According to the technical scheme, the thermal stability and the electrical safety of the data center cooling machine room are improved.

The invention discloses a main power grid short-time load prediction method using a hybrid active filter, and particularly relates to the technical field of load prediction. The method comprises the following steps: acquiring active control parameters and passive branch parameters of a hybrid active filter, combining a real-time load fluctuation signal of a main power grid, extracting harmonic suppression characteristics and phase distortion characteristics, and analyzing and generating a time scale compensation factor through a dynamic coupling effect; and constructing a phase correction model based on the transient harmonic residual component and the time scale compensation factor, and performing frequency domain and time domain combined reconstruction on the real-time load fluctuation signal to obtain a corrected load fluctuation characteristic sequence. A short-time load prediction model is calibrated through a collaborative mapping relation, a load power prediction value of a main power grid in a future preset time window is output, a secondary high-frequency interference signal generated by real load fluctuation and filter self-resonance is effectively distinguished, and the problem of coupling interference of harmonic residual components on the load prediction model in a power grid impedance sudden change scene is solved.

The invention relates to the technical field of wireless communication networks, and provides a low-channel electroencephalogram amplification circuit and brain-computer interface equipment oriented to an after-ear electroencephalogram signal, and the low-channel electroencephalogram amplification circuit comprises a dry electrode sensing module which is used for collecting an electroencephalogram signal; the front active amplification module comprises an operational amplifier circuit with high input impedance; the anti-aliasing filtering module is formed by cascading a multi-order passive filtering network and an active filtering circuit, is connected with the output end of the front active amplification module and is used for filtering high-frequency interference signals; the right leg driving feedback module comprises a programmable impedance adjusting circuit and a current limiting protection circuit, the right leg driving feedback module and the front active amplification module form a closed-loop feedback loop, and the output end of the right leg driving feedback module and the human body form a current loop through a protection resistor; the analog-to-digital conversion module adopts an integrated low-power-consumption analog front-end chip; a wireless transmission module; and the power supply management module provides independent power supply for the analog front-end chip, the operational amplifier circuit and the wireless transmission module.

The invention relates to the technical field of reactive power compensation of a power system, and discloses an active filter harmonic suppression and dynamic compensation system based on IGBT (Insulated Gate Bipolar Translator) multi-mode regulation and control. The system comprises a control module; the high-frequency harmonic detection module is electrically connected with the control module and is configured to detect a power grid harmonic signal in real time at a sampling rate of 200kHz and transmit the power grid harmonic signal to the control module; the IGBT gate driving compensation circuit is electrically connected with the control module and a preset IGBT module, and the control module dynamically adjusts the dead time and the switching frequency of the IGBT module through the IGBT gate driving compensation circuit; the IGBT junction temperature observer is electrically connected with the IGBT module and the control module and is configured to monitor the junction temperature of the IGBT module in real time and trigger the control module to start a derating protection mechanism when the junction temperature exceeds 125 DEG C; wherein the control module generates a PWM (Pulse Width Modulation) compensation waveform through a model prediction control algorithm unit based on a detection signal of the high-frequency harmonic detection module, so as to drive the IGBT module to execute harmonic compensation through the IGBT gate driving compensation circuit.

The invention discloses a power distribution network harmonic suppression method and system, and the method comprises the steps: building an objective function with the minimum total harmonic distortion rate of nodes of a whole network, building a power flow constraint, a harmonic distortion rate constraint and an active filter device related constraint, and obtaining a power distribution network harmonic suppression model according to the objective function and constraint conditions. A distributed partially observable Markov decision process is established based on the MADDPG algorithm, and harmonic suppression is performed on the power distribution network based on the distributed partially observable Markov decision process by using the PRE-combined MADDPG algorithm, so that the problem of low sample efficiency of a reinforcement learning algorithm is effectively solved, the stability of a training process and the convergence speed of the algorithm are promoted, and the robustness of the power distribution network is improved. According to the method, the effectiveness of the finally obtained harmonic suppression strategy is ensured, based on a centralized training-distributed execution architecture, it can be ensured that a plurality of active filter devices can make a cooperative control strategy giving consideration to the harmonic problem of the whole power distribution network in real time only by means of distributed observation, and therefore efficient whole network harmonic cooperative governance is achieved.

The invention provides a hysteresis loop analysis method for a transformer no-load loss test, and belongs to the technical field of transformers. Exciting voltage and current signals are collected in a transformer no-load state, and an active filter is used for carrying out digital filtering processing to eliminate harmonic interference; a data corresponding relation between magnetic flux density and magnetic field intensity is established through a digital integration algorithm and a magnetic field intensity calculation formula to form original hysteresis data, the original hysteresis data is processed by using a hysteresis loop optimization model, a complete hysteresis loop curve is generated, and the hysteresis loop area is calculated. According to the hysteresis loop area, the hysteresis loss power density is calculated through the iron loss calculation function, the total value of the transformer no-load loss is obtained by combining the eddy current loss calculation result, and the technical problems that the hysteresis loop reconstruction precision is not high and the complex hysteresis phenomenon cannot be adapted in the transformer no-load loss test are solved.

The invention discloses a multi-level pulse compensation type active EMI (Electro-Magnetic Interference) filter suitable for a multi-noise source switching power supply and a control method of the multi-level pulse compensation type active EMI filter. The invention provides a multi-level pulse compensation scheme based on switch behavior modeling, aiming at the problem of common-mode noise of adjacent rising edges and falling edges generated by a high-frequency switch in a multi-noise-source switching power supply. The time sequence delay and the edge slope of the compensation signal are calculated by analyzing the dv / dt characteristics in the switching-on and switching-off processes of the switching device, and accurate matching and offset with a noise source in phase and amplitude are achieved. Compensation control logic is realized by sharing a main control chip with a power circuit, and an additional controller and a high-precision sampling system are not needed; the self-adaptive tracking of the compensation amplitude is realized through the voltage following circuit; a multi-level compensation signal is output through the totem-pole circuit and injected into a common-mode path, and effective suppression of electromagnetic interference is achieved. The converter has the advantages of small size, low cost, simplicity and convenience in installation, high stability and the like, and is suitable for various multi-noise-source power electronic systems including a dual-active bridge converter, a phase-shifted full-bridge converter and an interleaving Buck converter.

The invention provides an electric energy quality treatment method, system and device based on a charging pile and a medium, and belongs to the technical field of charging piles, and the method is realized through the following steps: employing a mutual inductor to collect three-phase voltage / current; a common analog sampling and DSP processing circuit; harmonic / reactive power is identified based on the instantaneous reactive power theory, and a compensation instruction is generated; according to the compensation control instruction, driving an active filtering inverter circuit to inject compensation current into a power grid so as to reduce the total harmonic current content and improve the power factor; and the main controller generates charging state data according to the sampled voltage signal and current signal, and couples the data to an alternating current power line for transmission through the power line carrier communication module. The system guarantees the quality of the power grid, achieves the high efficiency and reliability of the operation of the charging pile, and gives consideration to the safety of the power grid and user experience.

The invention discloses a three-port high-voltage DC-DC converter with an active filtering bridge arm and a control method thereof, and relates to the field of power electronics. The invention aims to solve the problems that a multi-port topological structure needs a high-capacity magnetic element and the transmission efficiency is low. Two energy buffer bridge arms are connected in series; the energy transfer bridge arm is connected in parallel with the high-voltage-side and medium-voltage-side bridge arms; the low-voltage-side bridge arms are connected in parallel with two ends of the lower bridge arm; one ends of the high-pressure side valve group and the medium-pressure side valve group are connected with the energy transfer bridge arm, the other ends are respectively connected with the high-pressure side bridge arm and the medium-pressure side bridge arm, and two ends of the low-pressure side valve group are respectively connected with the low-pressure side bridge arm and the lower bridge arm. And the valve group is adjusted to be switched on or switched off, and the sum of output voltages of all half-bridge sub-modules is adjusted, so that the current flowing through the energy transfer bridge arm is trapezoidal wave, and charging or discharging is realized.

The invention discloses an intelligent power regulation system and method for a power distribution cabinet, and relates to the technical field of power regulation of the power distribution cabinet, and the method comprises the steps that a multi-source sensing unit carries out the early warning of harmonic overrun and local overheating risks in advance according to the collected three-phase current, three-phase voltage and harmonic components, and a temperature distribution matrix and external data generated by a thermal infrared imager; the edge prediction unit operates the LSTM-CNN-GRU hybrid neural network model to generate a future load prediction value, and stabilizes the voltage in advance; and the impedance self-adaptive execution unit enables the vibration value of the motor to be within a safety threshold value through the capacitor bank with the reconfigurable topology, the threshold value trigger type active filter and the tap switch controller according to the received optimization instruction.

A high-speed, low-noise laser signal detection apparatus, comprising a low-noise linear regulated power supply and a laser detection processing module. The low-noise linear regulated power supply (01-03) comprises an isolation unit (01), a voltage regulation and filtering unit (02), and a reference unit (03). The laser detection processing module (04-09) comprises a laser light signal detection input unit (05), a bias unit (04), a differential amplification unit (07), an active filtering unit (08), and an output interface unit (09). An output end of the voltage regulation and filtering unit (02) is connected to the reference unit (03) and the laser detection processing module (04-09). The reference unit (03) is connected to the bias unit (04) and is configured to provide a reference voltage to the bias unit (04). The bias unit (04) is configured to provide a bias voltage to the differential amplification unit (07). The differential amplification unit (07) comprises a multi-stage in-phase proportional differential amplification circuit, and the active filtering unit (08) comprises a multi-order active low-pass filter. According to the high-speed, low-noise laser signal detection apparatus, the detection bandwidth of a laser signal can be expanded, the signal-to-noise ratio of high-frequency pulse measurement can be reduced, and the anti-interference characteristics of a power supply can be improved.

The invention specifically discloses an ultrasonic guided wave edge real-time communication method and system based on an FPGA (Field Programmable Gate Array), and the method comprises the following steps: the FPGA of a guided wave communication transmitting circuit receives data needing to be transmitted, completes the data package construction and carrier modulation, and outputs a digital signal; after digital-to-analog conversion, a multi-stage power amplification circuit and a matching network circuit, the ultrasonic guided waves are transmitted to an excitation piezoelectric transducer, and the excitation piezoelectric transducer generates ultrasonic guided waves to be transmitted in a metal medium; the receiving piezoelectric transducer converts ultrasonic guided waves transmitted in a metal medium into piezoelectric signals, the piezoelectric signals sequentially pass through the active filter circuit, the variable gain amplification circuit and the analog-to-digital conversion circuit and are transmitted to the FPGA of the guided wave communication receiving circuit in the form of digital quantity, and the FPGA operates a demodulation algorithm to restore effective binary data. And the data is transmitted to other equipment. According to the technical scheme, the FPGA serves as a processing unit, high-frequency carrier modulation and real-time operation of a complex demodulation algorithm can be completed, and the high-speed communication requirement can be met.

A single-phase PWM rectifier direct-current side boost type active filter circuit control method based on a duty ratio feed-forward single current loop is characterized by comprising the following steps that inductive current of an active filter circuit is collected; collecting the direct current side current of the single-phase PWM rectifier; the method comprises the following steps: extracting a DC side current secondary pulsation component of a PWM rectifier as a reference current of an active filter circuit, performing high-pass filtering on the acquired inductive current of the active filter circuit to filter out a DC component, then subtracting the reference current, and enabling a deviation value to pass through a controller to obtain a current loop control component; the control component per unit of the current loop is added with the voltage control duty ratio Dv of the support capacitor of the active filter circuit for modulation to obtain a control signal of a corresponding switch tube. According to the method, a support capacitor voltage sampling circuit and a control loop of a traditional boost active filter circuit are omitted, the system hardware cost is reduced, the reliability is improved, and the control loop is simplified. The method is suitable for all active filter control which adopts a boost type active filter circuit for filtering on the direct current side, and applicable systems comprise single-phase rectification, single-phase inversion, multi-phase rectification, multi-phase inverters and the like.

Wireless circuitry can include a first filter circuit configured to output signals in a first frequency range, a second filter circuit configured to output signals in a second frequency range different than the first frequency range, and a signal combiner having a first input coupled to the first filter circuit and having a second input coupled to the second filter circuit. The wireless circuitry can further include a first switchable impedance matching circuit coupled between an antenna and the first filter circuit and a second switchable impedance matching circuit coupled between the antenna and the second filter circuit. The first and second filter circuits can be active filters such as lowpass-to-bandpass conversion filters operable in different frequency bands.

The invention relates to the technology of power electronics and electric energy quality control, in particular to an energy storage type UPQC and switch state prediction control method based on improved model prediction control, which comprises a series active filter, a parallel active filter, a direct current bus, an energy storage system and a controller, according to the control method, an energy storage power and charge state dynamic equation is introduced into an MPC prediction model, and a multi-objective cost function is designed. And the controller predicts and evaluates the candidate switching vector in each sampling period based on a finite control set model predictive control strategy, and outputs an optimal switching state through value function optimization, thereby realizing collaborative optimization of electric energy quality management and energy storage energy management. According to the method, the dynamic response capability and compensation precision of the UPQC under the working conditions of voltage sag / sag, imbalance, harmonic waves and load fluctuation are remarkably improved, meanwhile, the energy storage utilization efficiency and the system stability are improved, and the method is suitable for a power distribution network with new energy high permeability and large load fluctuation.

The invention relates to a precise data acquisition device of a lightning arrester on-line monitoring system, and the device comprises a sensor unit which is used for obtaining a three-phase leakage current signal of a lightning arrester and a voltage signal of a corresponding phase in real time; a signal conditioning unit; a micro-current amplification circuit; a dynamic gain control circuit; a multi-stage active filter circuit; an electromagnetic shielding housing; a synchronous sampling unit; a data processing unit; a self-energy-taking power supply unit; and an intelligent communication unit. The beneficial effects are that through the high-linearity current transformer and the partial pressure type voltage sensor of the sensor unit, three-phase leakage current signals and corresponding-phase voltage signals of the lightning arrester can be accurately obtained; a micro-current amplification circuit, a dynamic gain control circuit and a multi-order active filter circuit in the signal conditioning unit work cooperatively, weak leakage current signals are effectively processed, the signal-to-noise ratio is improved, and it is ensured that the signals can still keep high precision in a complex electromagnetic environment.

Wireless circuitry can include a first filter circuit configured to output signals in a first frequency range, a second filter circuit configured to output signals in a second frequency range different than the first frequency range, and a signal combiner having a first input coupled to the first filter circuit and having a second input coupled to the second filter circuit. The wireless circuitry can further include a first switchable impedance matching circuit coupled between an antenna and the first filter circuit and a second switchable impedance matching circuit coupled between the antenna and the second filter circuit. The first and second filter circuits can be active filters such as lowpass-to-bandpass conversion filters operable in different frequency bands.

The invention relates to the field of power grid state evaluation, discloses a power grid state evaluation method and system based on a high-capacity high-voltage active filtering structure, and realizes breakthrough in the fields of economic quantification of harmonic suppression, dynamic risk evaluation, multi-party collaborative decision, data security and the like through interdisciplinary fusion. According to the method, the multi-dimensional data of the active filter is obtained, processing and analysis are carried out by utilizing advanced technologies such as quantum calculation, results such as a quantum risk thermodynamic diagram, an equipment health degree attenuation curve and a Nash equilibrium decision path are generated, and scientific decision support is provided for power grid enterprises, users and supervision organizations. Meanwhile, an anti-interference asset configuration table is coded into a photon orbital angular momentum state, data topology protection is achieved through an optical annular cavity, and a quantum anti-counterfeiting supervision report with anti-counterfeiting performance and traceability is generated.

The invention relates to the technical field of low-voltage direct-current power supply, and discloses a direct-current active filtering method and system based on a three-level topological connection low-voltage direct-current power supply system. Firstly, a three-level topological active filter is connected with the low-voltage direct-current power supply system in parallel, so that the voltage stress of a switching tube is reduced; reference voltages under different working conditions are dynamically generated through a preset working condition proportionality coefficient, the compensation capacitor voltage can be more accurately adjusted, the compensation precision is improved, a processing mode of firstly adopting a proportional resonance controller and then adopting a proportional controller is adopted, so that the active filter more effectively suppresses various ripple components, and finally, the active filter can be effectively controlled. The three-level topological active filter can drive the switching tube to be switched on and switched off according to different modulation results, the filter inductor is flexibly controlled to generate the compensation current, finally, the compensation current injected into the low-voltage direct-current power supply system can be more effectively subjected to ripple filtering, and the ripple suppression capacity in the system is remarkably improved.

The application discloses a new energy automobile high-voltage bus temperature control active filter, and relates to the technical field of new energy automobiles, which comprises a filtering mechanism, an auxiliary mechanism is arranged in the main shell, the auxiliary mechanism comprises a micro high-pressure pump and a liquid storage tank, each liquid outlet end of the shunt pipe is communicated with a micro nozzle, a volute spring is additionally arranged between the inner wall of the circular ring and the bottom end of the disc, and a rotary joint is communicated with the top liquid outlet of the winding disc. The auxiliary mechanism can stabilize the temperature in the temperature control active filter under extreme conditions, so that the influence of the harmonic treatment effect of the temperature control active filter caused by the fact that heat is not completely discharged in time is avoided, and the use efficiency of the temperature control active filter is improved.

The invention discloses a novel elevator light curtain which comprises an all-plastic shell and a circuit board arranged in the all-plastic shell. The circuit board adopts a cascade multi-path switching module to gate a plurality of photoelectric units, and a grounding filter network is arranged at the output end of each photoelectric unit for source filtering; an active filtering buffer unit with a PNP triode as a core is introduced into a signal path, and a signal processing module comprising a four-stage operational amplifier and a gradient RC filtering network is adopted for step-by-step amplification and conditioning. Through systematic hardware circuit design, on the premise of not depending on metal shielding, internal and external electromagnetic interference is actively and multiply inhibited from the source to the terminal, meanwhile, the structure is simplified, the cost is reduced, the short circuit and failure risks possibly caused by shell grounding are thoroughly avoided, and higher reliability, environmental adaptability and economical efficiency are achieved.

A calibration method and a tuning method for an on-chip differential active RC filter are provided. The calibration method comprises: obtaining zero-crossing time of a differential signal outputted by a single-pole point real number filter by analyzing the single-pole point real number filter; setting a reference clock period according to the relationship between the zero-crossing time and the bandwidth of the single-pole point real number filter, and setting a calibration working time sequence according to the reference clock period; and scanning an RC configuration of an RC array according to the calibration working time sequence to realize calibration of the RC array.

The present disclosure relates to an isolated active EMI filter without an additional element on a power supply line to prevent noise emitted through a power supply line cable, the isolated active EMI filter comprising: a common mode choke disposed on a power supply side; a Y capacitor disposed on the EMI source side; a sensing winding sensing a current; an amplifying unit that amplifies the noise current; and the signal of the secondary coil is injected into the transformer of the Y capacitor as a compensation signal.

Dynamic extraocular filtering is a correction method to improve color contrast recognition in color vision deficient observers (non-normal color vision). This method is based on actively controlling wavelength spectrum transmission to retinal photoreceptors, introducing a temporal contrast that is interpreted as color contrast by the observer. The method functions by utilizing an active filter that produces several filter conditions which change at a high frequency. This method changes filter conditions dynamically as opposed to current systems which rely on static band-stop filters.

The utility model discloses power electronics equipment's test and debugging technical field relates to a kind of debugging device for active filter;Including cabinet;The cabinet inside is provided with voltage regulator, control module and power module;The control module is located above voltage regulator;The cabinet side is provided with aviation plug;The power module and voltage regulator are electrically connected;The voltage regulator and aviation plug are electrically connected;The aviation plug is electrically connected with active filter and control module respectively;The active filter and mutual inductor are electrically connected;The mutual inductor and control module are electrically connected;The voltage regulator and intelligent electric meter are electrically connected;The intelligent electric meter and control module and electrically connected.The utility model can realize the quick power-on test of active filter, parameter adjustment and performance verification.

The invention discloses a design method of a three-order active filtering automatic test system, and the method comprises the steps: controlling a PXI platform through LabVIEW programming to achieve the generation of a sweep frequency signal and the collection of filtering response, and completing the signal processing, characteristic analysis and result visualization. The system integrates six core technologies, namely a modularized hardware architecture, automatic process control, frequency domain parameter precision measurement, multi-order characteristic synchronous detection, software and hardware collaborative linkage and simulation data comparison. On the basis of retaining traditional functions such as setting waveform type, amplitude, sweep frequency range, sampling rate, trigger mode, recording cut-off frequency, gain and other parameters, exponential sweep frequency accurate excitation and adaptive signal acquisition are innovatively realized, link interference is reduced through matrix switch multi-channel scheduling, a LabVIEW parallel thread and a feedback node mechanism are combined, and the adaptive signal acquisition is realized. And closed-loop analysis of amplitude-frequency / phase-frequency characteristics and real-time drawing of a Bode diagram are completed.

The application discloses a novel elevator light curtain, comprising a full-plastic shell and a circuit board arranged in the shell. The circuit board adopts a cascade multi-path switching module to select multiple photoelectric units, and a grounding filter network is arranged at the output end of each photoelectric unit to perform source filtering; an active filter buffer unit with a PNP triode as a core is introduced into a signal path, and a signal processing module containing a four-stage operational amplifier and a gradient RC filter network is adopted to perform step-by-step amplification and conditioning. The application actively and repeatedly suppresses internal and external electromagnetic interference from the source to the terminal under the premise of not relying on metal shielding through systematic hardware circuit design, simultaneously simplifies the structure, reduces the cost, and completely avoids the short circuit and failure risk caused by the shell grounding, and has higher reliability, environmental adaptability and economy.

The present invention discloses an active filter protection method, comprising: obtaining the current flowing through the capacitor branch of the filter under normal circumstances; obtaining the action value of the double-ended differential protection based on the capacitor branch current; and determining whether to activate the differential protection based on the relationship between the action value and the action range. The present invention can protect the entire filter, eliminating dead zones in the protection range and operating conditions. Simultaneously, the use of a two-side differential algorithm provides stronger braking for out-of-zone faults and higher sensitivity for in-zone faults. Compared with multi-side differential protection, this method significantly improves the sensitivity and reliability of the protection, reduces the computational complexity and difficulty of setting coordination, and has wide applicability and high practicality.

The invention discloses an FF-FB cooperative four-unit active filter based on dual-core multiplexing. The FF-FB cooperative four-unit active filter comprises a noise source part, a load LISN network part and an active filter part, the active filter part comprises a current sampling branch, a first operational amplifier module, a second operational amplifier module, a voltage sampling branch, a plurality of current compensation branches, a first complementary output stage circuit and a second complementary output stage circuit; the two ends of the noise source part are connected with the left side of the active filter part, and the load LISN network part is connected with the right side of the active filter part. Feed-forward current sampling-current compensation is completed by using the multiplexing operational amplifier, and compensation is completed at the source end and the load end of the current transformer through two branches, so that secondary structure multiplexing is realized, and the problem that the operational amplifiers are added in topology is solved.