584 results about "High impedance" patented technology

A headset antenna and a connector for the same are provided. The headset antenna includes an audio signal line, an antenna and a high impedance element in specified application frequency ranges. The audio signal line is adapted for transmitting an audio signal and the antenna is adapted for receiving an RF signal. The high impedance element is disposed on a transmission path of the audio signal and generates a high impedance at a specified frequency band of the RF signal, so that the audio signal line is equivalent to an open circuit and the antenna obtains a better receiving capability.

A passivity-based dual-mode integrated control method for a grid-connected inverter (GCI) is provided. In view of the insufficient robustness of the conventional single-mode GCI in a high-impedance and low-inertia weak grid, and the problem of wideband oscillation of the grid voltage and grid current or even system instability in nonlinear application scenarios such as grid structure / parameter variation, and plug-and-play of the inverter, the dual-mode integrated control method performs modeling on the GCI based on a port-controlled Hamiltonian (PCH) model, thereby obtaining integrated control with a weighted passivity-based feedback control law for the GCI based on a grid-following (GFL) mode and a grid-forming (GFM) mode. Based on the dual-mode integrated control method, the stable operation of the GCI in severe grid conditions with large fluctuation of the impedance, and desirable robustness of the GCI in nonlinear working scenarios can be ensured.

The invention relates to the technical field of non-electrical variable control or regulation systems, and discloses a temperature rising blanket temperature closed-loop control method and system based on human body position recognition feedback, and the method comprises the steps: calculating a form compactness coefficient representing a heat dissipation boundary based on pressure data, and calling a mapping function to convert the form compactness coefficient into an equivalent thermal impedance estimated value; introducing the estimated value and dynamically constraining the forward channel gain of the temperature closed-loop controller according to a negative correlation strategy; according to the method, a real-time mapping mechanism of the contact topological characteristics and the control gain is constructed, so that the problem of model mismatch caused by body position change of the controlled object is solved; when the high-impedance contact state is detected, energy input is automatically reduced, the local heat accumulation effect is restrained, and the convergence and safety of the thermodynamic control process under the variable boundary condition are ensured.

The invention belongs to the technical field of new energy active support stability control, and provides a fan power decoupling method based on adaptive virtual impedance and feedforward compensation. According to the method, dynamic characteristics of active power and reactive power in the system are analyzed by combining a topological structure of a doubly-fed fan grid-connected system and fan internal control, and a small signal model is constructed based on power transmission characteristics. A self-adaptive virtual impedance strategy based on power grid impedance characteristic adjustment is introduced for the problem of power coupling caused by high line impedance in a weak power grid environment and dynamic and control loop characteristics of flux linkages in a fan. Meanwhile, through a disturbance component extraction and feedforward control strategy, a disturbance signal in rotor current is introduced into a power ring for adjustment, and power decoupling control is realized. The method overcomes the limitation that an existing decoupling control technology is poor in effect, the control principle is clear, engineering implementation is easy, and the stability and the dynamic response capability of the doubly-fed fan in the weak power grid environment can be improved.

In one implementation, an apparatus, such as an ESD protection circuit, is disclosed. The apparatus can include a filter coupled between a local supply voltage rail to a supply voltage rail. A switch circuit can be connected in parallel with the filter. The apparatus can include a clamp configured to 1) provide a first ESD shunt path from an input line to the local supply voltage rail and 2) provide a second ESD shunt path from the input line to a lower voltage rail. A second clamp can be configured to provide a third ESD shunt path from the local supply voltage rail to the lower voltage rail. The switch circuit can be configured to close a switch to bypass the filter.

The invention provides an adaptive stochastic resonance weak fault detection method based on kurtosis optimization, and belongs to the technical field of fault detection, and the method comprises the steps: collecting and preprocessing a transient signal on a cable line; constructing a bistable stochastic resonance model; kurtosis of the output signal is used as a fitness function, and potential well parameters of the bistable stochastic resonance model are optimized based on a particle swarm optimization algorithm; and substituting the optimized potential well parameter into the bistable stochastic resonance model, and processing the preprocessed transient signal to obtain an enhanced output signal for fault detection. The method has the beneficial effects that the stochastic resonance system is constructed on the basis of the classical bistable model, the kurtosis of the output signal is used as the fitness function of the particle swarm optimization algorithm, the potential well parameters are adaptively optimized, the potential well parameters are driven to automatically converge to the optimal state, and the robustness of the system is improved. The high-impedance grounding fault traveling wave signal can be extracted and enhanced from a strong noise background, and the detection sensitivity and reliability are improved.

The invention belongs to the technical field of electrical equipment fault monitoring, and discloses a fault monitoring system for electromechanical installation engineering, which comprises a high-impedance fault identification module, extracts nonlinear harmonic features through current signals, constructs a frequency domain-time domain joint feature set in combination with space-time magnetic distortion in an electromechanical installation process, and performs fault identification on the nonlinear harmonic features through the high-impedance fault identification module. Non-linear characteristic response identification of the high-impedance fault is carried out, and a high-impedance fault characterization result is output; the transient fault capturing module is used for positioning a risk time window according to a high-impedance fault characterization result, and identifying the starting and ending boundaries of an electrical disturbance behavior in combination with a double-threshold mutation mechanism; synchronously extracting corresponding operation condition parameters, constructing a short-time process behavior model taking electrical disturbance as a source, and outputting a transient disturbance sequence; and the sensitivity of fault identification, the accuracy of positioning and the real-time performance of diagnosis are integrally improved.

The invention belongs to the technical field of electromagnetic wave absorption, and particularly discloses a three-dimensional structure wave-absorbing metamaterial which comprises a first three-dimensional structure layer, a second three-dimensional structure layer and a metal backboard which are sequentially arranged from top to bottom, the first three-dimensional structure layer comprises a first top layer and a first three-dimensional absorption enhancing framework arranged on the lower surface of the first top layer, and the second three-dimensional structure layer comprises a second top layer and a second three-dimensional absorption enhancing framework arranged on the lower surface of the second top layer. A first high-impedance metasurface and a second high-impedance metasurface are loaded on the lower surface of the first three-dimensional absorption enhancement skeleton at intervals; the second three-dimensional structure layer comprises a second top layer and a second three-dimensional absorption enhancement skeleton arranged on the lower surface of the second top layer, and a third high-impedance metasurface is loaded on the top surface of the second top layer. By adopting the three-dimensional structure wave-absorbing metamaterial, ultra-wideband absorption and large-angle stability can be achieved under the condition that the thickness is small, light and thin wideband application of a wave-absorbing body is facilitated, and the three-dimensional structure wave-absorbing metamaterial has great practical value in the field of electromagnetic compatibility.

The invention discloses a power distribution network fault type identification method based on big data, and relates to the technical field of power distribution network fault type identification. Multi-source data time axes are aligned on the premise of keeping original sampling precision through clock drift correction and a self-adaptive interpolation algorithm; the problem of misjudgment faults or missed judgment faults caused by asynchronous voltage / current signal time is thoroughly eliminated; low confidence is marked for communication delay data, participation in calculation is limited, and noise interference feature extraction is avoided; on the basis of a fault type association mechanism of a misjudgment sample, a network layer needing to be adjusted is accurately positioned, and resource overhead of full-model retraining is avoided; the scarce fault data is expanded by combining an adversarial sample generation technology, and the recognition robustness of complex scenes such as high-impedance grounding is improved.

The invention discloses a sensor array acquisition system for detecting gas, and relates to the field of gas sensors. The sensor array acquisition system for detecting gas comprises a gas sensor array, a signal conditioning circuit, an analog-to-digital conversion module, a control module and a power supply module. According to the sensor array acquisition system for detecting the gas, the voltage follower circuit with high input impedance is adopted, so that the problem of attenuation during signal acquisition of a high-impedance sensor is effectively solved, and the signal acquisition precision is improved. Through the adjustable direct-current bias circuit and the differential amplification circuit, the dynamic adjustment of the measurement range is realized, the gas detection requirements of different concentration ranges can be met, and hardware does not need to be replaced. A constant-current driving chip is adopted to control a sensor heating circuit, heating current can be accurately set by adjusting external resistance, it is ensured that the sensor works at the optimal temperature, and the stability and response speed of the sensor are improved.

An acoustic matching structure is used to increase the power radiated from a transducing element with a higher impedance into a surrounding acoustic medium with a lower acoustic impedance. The acoustic matching structure consists of a thin, substantially planar cavity bounded by a two end walls and a side wall. The end walls of the cavity are formed by a blocking plate wall and a transducing element wall separated by a short distance (less than one quarter of the wavelength of acoustic waves in the surrounding medium at the operating frequency). The end walls and side wall bound a cavity with diameter approximately equal to half of the wavelength of acoustic waves in the surrounding medium. In operation, a transducing element generates acoustic oscillations in the fluid in the cavity. The transducing element may be an actuator which generates motion of an end wall in a direction perpendicular to the plane of the cavity to excite acoustic oscillations in the fluid in the cavity, and the cavity geometry and resonant amplification increase the amplitude of the resulting pressure oscillation. The cavity side wall or end walls contain at least one aperture positioned away from the center of the cavity to allow pressure waves to propagate into the surrounding acoustic medium.

The invention relates to the technical field of radio frequency integrated circuits, in particular to a harmonic suppression power amplifier combining a matching network and a feed network, which comprises a transistor, an input matching module, an output matching module, a stabilizing module and a bias module, the input matching module comprises a first parallel resonance unit, the first parallel resonance unit is used for second harmonic suppression, the output matching module comprises a series resonance unit and a second parallel resonance unit, the series resonance unit is used for resonating at a second harmonic frequency and performing low-impedance grounding on the second harmonic, and the second parallel resonance unit is used for resonating at a second harmonic frequency and performing low-impedance grounding on the second harmonic. The second parallel resonance unit is used for resonating at a third harmonic frequency and forms a high-impedance open circuit for the third harmonic, the output matching module is coupled to a drain electrode of the transistor, and the bias module comprises a grid bias sub-module and a drain bias sub-module. The grid bias sub-module is coupled to a connection node of the input matching module and the grid of the transistor, the drain bias sub-module is coupled to the output matching module, and the bias voltage of the transistor is jointly determined by the grid bias sub-module and the drain bias sub-module. The power amplifier has the effect of improving the efficiency level of the power amplifier while realizing harmonic suppression optimization.

The invention discloses a peak code modulation circuit based on a dynamic memristor, which comprises the dynamic memristor and a signal conversion module, and is characterized in that the signal conversion module comprises a signal isolation module, a feature extraction module and a pulse conversion module which are connected in sequence. The dynamic memristor generates a voltage signal with a slow-rising and steep-falling characteristic under constant current input. The signal isolation module comprises a high-impedance input buffer circuit; the feature extraction module comprises an asymmetric time constant signal processing circuit used for performing enhanced extraction on the steep drop feature of the memristor output signal; and the pulse conversion module comprises a dual-threshold positive feedback hysteresis comparison circuit and is used for converting the output signal of the feature extraction module into a rectangular digital pulse. The circuit is specially designed according to the characteristics of the memristor, is simple in structure, is easy to integrate, can achieve the efficient conversion from an analog signal to a standard digital pulse, and is suitable for the fields of neuromorphic calculation and low-power-consumption signal processing.

The utility model relates to a power supply device and a testing machine, the power supply device comprises a main loop, a voltage loop, a current loop and a clamping circuit, in a pressurization mode, when a detection current output by the clamping circuit at the current loop is in a set current clamping range, the output impedance is high resistance; and when the detection current output by the current loop is not in a set current clamping range, the clamping circuit triggers the clamping current to carry out analog output, and the output impedance is switched to low resistance, so that the output of the main loop is equivalent to a constant current source. In the current adding mode, when the detection voltage output by the clamping circuit at the voltage loop is within a set voltage clamping range, the output impedance is high resistance; and when the detection voltage output by the voltage loop is not in a set voltage clamping range, the clamping circuit triggers the clamping voltage to perform analog output, and the output impedance is switched to low resistance, so that the output of the main loop is equivalent to a constant voltage source. The simulation regulation function is achieved, and the response speed is high.

The invention relates to the technical field of lithium ion batteries, in particular to a halogenated electrolyte modified low-impedance positive electrode and a preparation process and application thereof. The problem that an existing lithium ion battery positive electrode material is high in impedance is solved. According to the preparation method, the carbon-coated aluminum foil is used as the positive current collector, so that the positive current collector has relatively low contact resistance and relatively high adhesion, the charge transfer resistance and the internal resistance of the battery are reduced, and the rate capability and the cycle performance of the battery are improved; a positive active material is added, C6H12O6.H2O is adopted for carbon coating to improve the electron transmission capacity of lithium iron phosphate, titanium-vanadium co-doping synergistically improves the electron conductivity, and the electron conduction impedance is reduced; the halide solid electrolyte coats lithium iron phosphate to inhibit side reaction and reduce interface impedance; carbon nano tube coating inhibits particle aggregation and reduces charge transfer impedance; and the modified conductive agent and the modified binder are added, so that the lithium ion battery has higher cycling stability, electrochemical activity and lower impedance.

The invention provides a two-stage current intensity adjusting method for an eye therapeutic apparatus, and the method comprises the steps: extracting the impedance effect intensity of a current at a macular center through recognizing the thickness of an impedance barrier layer corresponding to the current limiting degree of a high-impedance region, and combining with the actual penetration thickness, and obtaining the current penetration depth reduction proportion of the current penetration depth at the macular center; the current intensity imbalance degree of the coarse adjustment basic current intensity in the transition subarea is evaluated, and by obtaining the current intensity increase and decrease multiple of the fine adjustment compensation current intensity, the gradient difference between high impedance limitation and low impedance permeation is integrated, and the current intensity is compensated to balance the current intensity imbalance degree of the transition subarea; and updating the current output power level of each partition according to the fine adjustment compensation current intensity, and feeding back the current output power level to a therapeutic instrument circuit in real time to obtain uniform therapeutic intensity distribution so as to be matched with the decreasing proportion of impedance of impedance gradient distribution from high to low.

The invention discloses an electric power system transient stability rapid response control method and system, and relates to the technical field of electric power systems, and the method comprises the steps: collecting a transient harmonic current signal generated by a power grid fault in real time through a harmonic detection unit connected to a DC bus of an energy storage converter, and calculating the phase offset of the transient harmonic current signal; generating a power control instruction through a pre-configured hardware mapping circuit based on the phase offset; acquiring a current differential signal by using a power grid line current sensor, and identifying a path of transient energy flowing to a key unit based on a power grid topological structure; for the path, dynamically forming a virtual high-impedance wall on the target line; and on a consumption path predefined according to the power grid topological structure, controlling the energy storage converter to operate in a current source mode and configuring a reverse power characteristic so as to absorb the energy flow turned by the virtual high-impedance wall.

The invention relates to the technical field of manganese zinc ferrite materials, and particularly discloses a manganese zinc ferrite high-frequency high-impedance material and a preparation process thereof. The manganese zinc ferrite high-frequency high-impedance material is prepared from the following raw materials: Fe2O3, Mn3O4, ZnO, a carbon nanotube loaded rare earth oxide composite material, P2O5, Co2O3 and CaCO3. The preparation raw materials of the carbon nanotube loaded rare earth oxide composite material comprise a multi-walled carbon nanotube and a rare earth salt, and the mass ratio of the multi-walled carbon nanotube to the rare earth salt is 1: (0.12-0.14). According to the invention, the loss capability of the manganese zinc ferrite material to electromagnetic interference is enhanced, and the problem that the magnetic conductivity and impedance of the material are reduced in a high-frequency environment is solved.

The invention relates to the technical field of power equipment on-line monitoring and fault diagnosis, and discloses a converter transformer bushing end screen voltage abnormity detection device and early warning method.The method comprises the steps that voltage data are collected through a wireless intelligent sensor, soft synchronization and self-adaptive windowing are achieved through a commutation notch feature locking mechanism, and a preprocessing signal is output; topological correlation clustering is executed to construct a virtual health reference, a dynamic residual sequence is extracted through time domain difference, and system side and equipment side features are decoupled; constructing a variational mode decomposition model, and calculating a characteristic entropy value of the intrinsic mode function; and comparing the entropy value with a threshold value, triggering an active impedance disturbance verification mechanism, controlling a sensor to access a load and comparing an actual voltage drop rate with a theoretical voltage drop rate, and determining an insulation degradation or poor contact fault. High-precision synchronization can be achieved without a hardware clock, and the problems that weak fault features are difficult to extract and virtual connection and insulation faults are difficult to distinguish in a high-impedance loop are effectively solved.

The invention discloses a multi-terminal flexible direct current transmission line protection method based on injection signals, and relates to the technical field of power distribution network line protection. After the bipolar short-circuit fault is detected, the modularized multi-level converter is controlled to enter an active current limiting mode, and the fault current is limited to be 1.1 times of rated current, so that the impact on equipment is reduced; a main control station injects current sinusoidal signals with different angular frequencies twice, current and voltage signals of a port of the main control station are extracted, the impedance amplitude difference under the two angular frequencies is obtained, and the fault section protection method based on the impedance amplitude difference is established. Through a cut-and-trial method, the number of current-limiting reactors through which fault current flows is calculated, a criterion for matching and detecting a fault line section is established, and the fault section is isolated by a protection action. According to the method, synchronous communication is not needed, fault line protection can be realized under high resistance and noise, and the protection reliability and the recovery efficiency of the complex topology multi-terminal flexible direct current power grid are remarkably improved.

An apparatus for providing signals to a device may include one or more radiofrequency signal generators, and electrically-small transmission line, which couples signals from the one or more RF signal generators to the fabrication chamber. The apparatus may additionally include a reactive circuit to transform impedance of the electrically-small transmission line from a region of relatively high impedance-sensitivity to region of relatively low impedance-sensitivity.

The present invention provides an acoustic resonator device (1) having a resonator (R) comprising: a first electrode (2), a second electrode (3) arranged at a distance from the first electrode (2) in a first direction (z), wherein the first electrode (2) and the second electrode (3) extend along planes (E) arranged perpendicular to the first direction (z); and a layer stack (S) arranged between the first electrode (2) and the second electrode (3), which layer stack comprises a first piezoelectric layer (4) and a second piezoelectric layer (5), wherein the first piezoelectric layer (4) and a second piezoelectric layer (5) comprise a piezoelectric material, and an acoustic high-impedance layer (6) arranged between the first piezoelectric layer and the second piezoelectric layer;wherein an acoustic thickness (DR) of the resonator in the first direction (z) is n times half an acoustic wave (W) of a predetermined frequency, where n is a natural number greater than one. The invention also provides a corresponding filter component (10).

Provided is a magnetic core that has high impedance relative permeability in the high frequency range. The magnetic core comprises a plurality of magnetic laminates. The magnetic laminates are formed by layering thin soft-magnetic metal strips and have a height that corresponds to the length in the short direction of the thin soft-magnetic metal strips. The magnetic laminates are stacked in the height direction with a gap therebetween.

An apparatus may include a display stack, an ultrasonic sensor stack and a high-impedance stack including one or more high-impedance layers. The ultrasonic sensor stack may include an ultrasonic transceiver layer and an ultrasonic transceiver circuitry (UTC) layer. Each of the high-impedance layers may have an acoustic impedance that is higher than an acoustic impedance of the UTC layer. The high-impedance stack and the ultrasonic sensor stack may form an acoustic resonator bounded by the UTC layer and the high-impedance stack. The acoustic resonator may be configured to enhance the ultrasonic waves transmitted by the ultrasonic sensor stack at a peak frequency of the ultrasonic sensor stack. The peak frequency may be a frequency used by the ultrasonic sensor stack for obtaining fingerprint images. An apparatus stack portion that includes the ultrasonic sensor stack may have a thickness corresponding to a multiple of a quarter wavelength at the peak frequency.

The invention discloses an impedance matching plate, an impedance matching system and an impedance matching method, and relates to the technical field of electronic engineering, the impedance matching plate comprises a control module and a series resistance module, the series resistance module comprises a plurality of resistor gating modules connected in series and a first switching device, the resistor gating modules are respectively arranged on different target resistor units, and the first switching device is connected with the control module. Each resistor gating module comprises resistors with different resistance values and a second switching device which are connected in parallel, and the control module receives a resistance value adjusting instruction containing a target resistance value and generates a control signal according to a resistance value setting field in the resistance value adjusting instruction; the series resistance module conducts the target resistance gating module connected with the first switching device corresponding to the target resistance unit according to the control signal, and conducts the resistor corresponding to the second switching device in the target resistance gating module to generate a target resistance value, so that the problems that the large-range resistance adjustment cannot be realized and the impedance matching efficiency is low can be solved; the technical effects of adjusting the resistance in a large range and improving the impedance matching efficiency are achieved.

The invention discloses a short-circuit fault current limiter and a control method thereof. The current limiter comprises a capacitor, two IGBT (Insulated Gate Bipolar Translator) modules and four diode groups, when the line has no short-circuit fault, the two IGBT tubes are controlled to be conducted, and line current flows from the first end of the line to the second end of the line through one IGBT module or flows reversely through the second IGBT module; when a short-circuit fault occurs at the first end of the line, the two IGBTs are controlled to be switched off, the line current flows to the first end of the line from the second end of the line through the first diode group, the capacitor and the fourth diode group, and the capacitor is charged to enable the line to present high impedance so as to restrain the short-circuit current; when a short-circuit fault occurs at the second end of the line, the two IGBTs are controlled to be turned off, the line current flows to the first end of the line from the first end of the line through the third diode group, the capacitor and the second diode group, and the capacitor is charged to enable the line to present high impedance so as to restrain the short-circuit current. The short-circuit fault current limiter is high in response speed and low in equipment cost.

A filter stage system comprising a continuous-time baseband filter comprising a feedback loop employing at least one first impedance node and at least one second impedance node, wherein the at least one first impedance node has a higher impedance than the at least one second impedance node, and wherein the at least one first impedance node provides a dominant pole and the at least one second impedance node provides a non-dominant pole, and wherein the continuous-time baseband filter generates a filtered current, and a mirror component mirrors the filtered current to an output.

The invention provides a hybrid distribution transformer low-voltage turn-on overcurrent protection device and protection strategy combined with a current limiter, and the device comprises a hybrid distribution transformer which is composed of a power frequency electromagnetic part and a high-frequency power electronic part, and the power frequency electromagnetic part comprises a power transformer and a series transformer. The high-frequency power electronic part comprises converters which are connected back to back; the saturated iron core fault current limiter is integrated in a main loop of the hybrid distribution transformer, presents low impedance during normal operation, and is switched to a high impedance state through iron core desaturation to limit fault current during fault; the bypass switch module is connected to the input side of the high-frequency power electronic part, and when the fault current exceeds a set threshold value, the bypass switch module is conducted to bypass and isolate the high-frequency power electronic part within less than or equal to 1ms, and the continuous power supply of the power-frequency electromagnetic part is maintained; and the fault isolation device is configured at the two ends of the hybrid distribution transformer, and performs breaking operation in response to the current setting value and the low voltage setting value after current limiting so as to realize fault area isolation.

Technologies for impedance matching networks for qubits are disclosed. In one illustrative embodiment, an impedance matching network matches a 50 Ohm transmission line to a spin qubit with a state-dependent resistance of 100 kiloohms to 105 kiloohms. The illustrative impedance matching network is tunable, allowing the impedance transformation ratio to be changed without significantly changing the matching frequency of the impedance matching network. In some embodiments, the impedance matching network matches a 50 Ohm transmission line to a lower-resistance state of a qubit. In other embodiments, the impedance matching network matches a 50 Ohm transmission line to an impedance value in between a lower-resistance state and a higher-resistance state of a qubit.

The invention relates to the technical field of lithium batteries, and discloses a lithium battery cell with internal short circuit self-open circuit protection. Comprising a shell, an electrode assembly arranged in the shell, electrolyte, a positive pole and a negative pole, the positive pole and the negative pole are electrically connected with a positive electrode and a negative electrode of the electrode assembly respectively, and the electrode assembly comprises a positive plate, a negative plate and a diaphragm spaced between the positive plate and the negative plate; the battery is characterized in that a temperature or current sensitive fusible or high-resistance variable structure is integrated on the current collector of the positive plate and / or the negative plate, and the structure can automatically form a physical open circuit or a high-impedance area on a current path where a fault point is located when local temperature rise or sudden current increase exceeds a preset threshold value due to internal short circuit of the battery cell; therefore, short-circuit current is rapidly inhibited and thermal runaway spreading is prevented. By constructing a fuse or current gate type intrinsic safety structure in the current collector, the problems that when an existing lithium battery is subjected to internal short circuit (such as diaphragm failure, metal dendritic crystal puncture, impurity mixing and the like), a short circuit loop cannot be automatically cut off, so that current is intensively released, the temperature is sharply increased, and the service life of the lithium battery is influenced are solved. And the major safety problems of thermal runaway, fire and even explosion are further caused.