283 results about "Shunt capacitance" patented technology

An IPD high-selectivity band-pass filter based on a weak coupling transformer technology comprises an LC parallel resonance circuit, an LC series resonance circuit, an LC parallel resonance circuit and a fourth capacitor C4, and inductors in the LC parallel resonance circuit and inductors in the LC parallel resonance circuit have a weak transformer coupling relation; the coupling coefficient required by the weak coupling transformer provided by the invention is very small and can be realized in a mode of adjacently placing metals on the same layer, so that the structural complexity of the filter is effectively reduced; the band-pass filter is based on an IPD technology, an extra decoupling equivalent inductor is introduced through a weak transformer coupling technology, the extra decoupling equivalent inductor and a parallel capacitor which is connected between the input end and the output end of the filter in a bridging mode form a new resonance path, and a transmission zero point is introduced into an upper stop band and a lower stop band of the filter respectively to improve the selectivity of the filter. According to the invention, the selectivity of the filter can be effectively improved on the premise of not additionally introducing an inductance element and not increasing the order of the filter.

The invention provides a signal acquisition system of a photoelectric detector. In the signal acquisition system, a transimpedance pre-amplification circuit is arranged at the output end of the photoelectric detector, and a passive high-pass filter circuit is connected between the transimpedance pre-amplification circuit and a post-voltage amplification circuit. And a feedback network is formed in the transimpedance pre-amplification circuit and is used for converting a current signal output by the photoelectric detector into a proportional first voltage signal and outputting the proportional first voltage signal. The filter circuit is a third-order LC high-pass filter circuit and is used for suppressing direct current, low frequency and self-beat frequency components and keeping a 10-90MHz pass band flat. The rear voltage amplification circuit adopts a voltage amplification structure of a voltage operational amplifier, the voltage gain Av is 6-10, and the super-band gain is limited through a shunt capacitor. According to the embodiment of the invention, through the structure and parameter setting, the noise gain peak value is suppressed, and the system stability is improved.

The present disclosure relates to a current sensing system for a magnetic resonance imaging (MRI) scanner operating at 1H and 23Na resonant frequencies. The system includes a dual-tuned RF coil with a network of up to two parallel quarter-wavelength transmission lines, each integrated with a PIN diode-coupled shunt capacitor. A multiple half-wavelength transmission line is employed with a corresponding pair of shunt capacitors and PIN diodes. A quarter-wavelength transmission line, coupled with a power amplifier through a matching network of shunt capacitors and PIN diodes, is also included. The configuration parameters are designed to tune the system to the fundamental frequency and its first odd multiple, correlating with the 1H resonant frequency, and to the 23Na resonant frequency. The system accurately senses coil currents by detecting voltage variations in the matching network, thereby facilitating precise current measurements at the tuned resonant frequencies without the need for external sensors.

Disclosed is a device that decouples switching speed and gate delay time using an improved voltage-source gate driver. A shunt capacitor and a shunt resistor are connected in series to parallel across gate resistors of a voltage-source gate driver. The shunt capacitor and shunt resistor allow the gate delay and switching speed effect of the gate resistors to be decoupled. The shunt capacitor provides an initial high charge voltage and discharge gate current to reduce gate delay time. The shunt resistor modifies the effective gate resistance, which affects the gate current and the resulting switching speed. Shunt capacitor and shunt resistor values are determined to achieve the desired switching speed control with minimum gate delay time. When multiple power devices are paralleled, a common gate resistor, a shunt resistor and a capacitor combination is used. Each power device is also provided a respective split-gate resistor.

The invention discloses a coordination control method and related equipment for a network-construction-type flexible direct current converter station. The method comprises the following steps: firstly, determining the maximum capacitive reactive power capacity of the network-construction-type flexible direct current converter station; simulating a fault through time domain simulation, and calculating dynamic reactive power required for guaranteeing the stability of the transient voltage of the hub bus; selecting a parallel capacitor bank close to a grid-connected point to form a collaborative resource set, and initializing and distributing the input capacity of the collaborative resource set; taking the flexible direct current reference voltage, the active power and the capacitor input capacity as boundaries, taking maximization of a static voltage stability index as a target, executing continuous power flow optimization, calculating reactive power reserve capacity, and sending a control target after conditions are met. According to the invention, excessive consumption of flexible direct-current reactive power reserve is avoided by determining the capacity reference, and the dynamic reactive power demand is accurately calculated to ensure fault support; the cooperative capacitor bank supplements insufficient static resources and reduces flexible DC burden; through continuous power flow optimization, overall planning of steady-state and transient-state voltage stability is achieved, and the comprehensive supporting capacity of the network-constructing flexible direct current power supply to the voltage stability of the power grid is effectively improved.

An example power splitter and associated methods are provided herein. In some embodiments, the power splitter may include a first port. In some embodiments, the power splitter may include a plurality of second ports. In some embodiments, the power splitter may include one or more low pass elements. In this regard, the one or more low pass elements may include at least one series inductor and at least one shunt capacitor. In some embodiments, the power splitter may include one or more high pass elements. In this regard, the one or more high pass elements may include at least one series capacitor and at least one shunt inductor. In some embodiments, each of the one or more high pass elements and each of the one or more low pass elements is electrically connected to the first port and the plurality of second ports.

A current sensing system for a magnetic resonance imaging (MRI) scanner operating at 1H and 31P resonant frequencies includes a dual-tuned RF coil with a network of up to two parallel quarter-wavelength transmission lines, each integrated with a PIN diode-coupled shunt capacitor. A multiple half-wavelength transmission line is employed with a corresponding pair of shunt capacitors and PIN diodes. A quarter-wavelength transmission line, coupled with a power amplifier through a matching network of shunt capacitors and PIN diodes, is also included. The configuration parameters are designed to tune the system to the fundamental frequency and its first odd multiple, correlating with the 1H resonant frequency, and to the 31P resonant frequency. The system accurately senses coil currents by detecting voltage variations in the matching network, thereby facilitating precise current measurements at the tuned resonant frequencies without the need for external sensors.

The invention discloses an intermediate frequency filter chip based on a gallium arsenide IPD process, which adopts the GaAs IPD process with three metal layers and comprises six resonators, twelve capacitors and three metalized grounding holes. The six resonators are composed of capacitors C1-C6 and inductors L1-L6 which are connected in series / in parallel, the inductors are all of self-built octagonal structures, and wiring is only conducted on the middle layer and the uppermost metal layer; a branch series capacitor Ca-Cc and a main parallel capacitor Cd-Cf respectively form six transmission zeros outside a low-frequency band and a high-frequency band. According to the invention, the characteristics of small size and wide band of the filter chip are realized, the loss is reduced, the in-band flatness is improved, and the filter chip has high frequency selectivity and high out-of-band rejection capability.

The invention provides a parameter design method for a multi-voltage rectification LCC converter, and the method comprises the steps: building a voltage precise mathematical model of a resonant cavity parallel capacitor through employing a fundamental wave equivalent method based on the condition that output capacitors of the multi-voltage rectification LCC converter and a multi-voltage rectifier participate in resonance; the gain of the voltage-multiplying LCC resonant converter is modeled through a voltage accurate mathematical model of a resonant cavity shunt capacitor; determining the number of rectifier bridges, the turn ratio of a transformer and the capacitance value of a rectification voltage-multiplying capacitor according to the voltage of the parallel capacitor of the resonant cavity and the gain of the voltage-multiplying LCC resonant converter; and determining values of the resonant cavity series-parallel capacitor and the resonant cavity inductor according to the capacitance value of the rectification voltage-multiplying capacitor. According to the method, analysis and calculation of the output filter capacitance are incorporated into parameter design of accurate modeling, a scheme for selecting the number of the voltage doubling rectifier bridges is given, and the size can be reduced and economic benefits can be increased under the condition that working condition requirements are met.

The invention relates to a circuit device for reactive power compensation in an inductive charging device, an inductive charging device, and a system for inductive energy transmission. The circuit device comprises two input terminals for connecting a voltage supply unit or a voltage collector unit; two output terminals for connecting a first or second energy coil; a compensation circuit unit with a serial capacitance arranged between an input terminal and an output terminal and / or a parallel capacitance arranged between the two input terminals or the two output terminals; and at least one switching unit arranged in the compensation circuit unit for breaking the electrical connection between this input terminal and this output terminal and interrupting a current flow through an energy coil connected to the output terminals.

The invention relates to the technical field of camera shooting, and discloses a ball type anti-shake motor and electronic equipment. According to the ball type anti-shake motor, a circuit board is provided with an emitting polar plate, a first rotor is provided with a first floating polar plate, and a second rotor is provided with a second floating polar plate opposite to the first floating polar plate; a first receiving polar plate is further arranged on the circuit board, and the first receiving polar plate and the first floating polar plate are oppositely arranged; the first receiving polar plate and the first floating polar plate form a first capacitor, the first floating polar plate and the second floating polar plate form a second capacitor, the second floating polar plate and the shell are oppositely arranged to form a third capacitor, and the transmitting polar plate and the first floating polar plate form a fourth capacitor; a series capacitor and parallel capacitor combined capacitive detection unit is constructed by the plurality of capacitors, and the detection result of the capacitive detection unit is changed through the change of the parallel capacitance value, so that the sensitivity of position detection is improved.

A Doherty power amplifier (PA) includes a main amplifier, an auxiliary amplifier, and a power splitting and phase shifting circuit configured to receive an input radio frequency (RF) signal, split the input RF signal into a first RF signal and a second RF signal, output the first RF signal to an input of the main amplifier, output the second RF signal to an input of the auxiliary amplifier, and provide a phase shift between the first RF signal and the second RF signal. The Doherty PA also includes a shunt inductor coupled to an output of the main amplifier, a shunt capacitor coupled to an output of the auxiliary amplifier, and a transformer. The transformer includes a first inductor coupled between the output of the main amplifier and the output of the auxiliary amplifier, and a second inductor magnetically coupled with the first inductor.

The invention provides a millimeter wave radio frequency power amplifier and a millimeter wave radio frequency transceiver, in the amplifier, an input differential signal is connected to grid electrodes of an amplification tube pair transistor and an auxiliary tube pair transistor through an auxiliary tube pair transistor blocking capacitor and an amplification tube pair transistor blocking capacitor; source electrodes of the auxiliary tube pair tube and the amplifier tube pair tube are grounded. The first amplifier tube is connected with the drain electrode of the first common-gate tube and the source electrode of the first auxiliary tube; the second amplifier tube is connected with the drain electrode of the second common-gate tube and the source electrode of the second auxiliary tube; grid electrodes of the common-gate pair transistors are connected; common-gate tube grid bias voltage is connected to grids of the common-gate tube geminate transistors through the bias resistor, and the other end of the grounding capacitor is connected to the grids of the common-gate tube geminate transistors; the drain electrode of the common-gate pair transistor is connected to the shunt capacitor and the main coil inductor of the output balun, and the secondary coil inductor of the output balun is connected with a single-ended output signal. According to the radio frequency power amplifier, OP1dB of the radio frequency power amplifier can be improved under the condition that the working voltage of the power amplifier is not increased.

The invention discloses a power grid voltage stability evaluation method and system, which are applied to the field of voltage stability evaluation, and the method comprises the steps: determining a low-frequency component and a high-frequency component of each node of a target power grid; voltage sag information of the corresponding node is obtained; determining a first target node according to an analysis result of the voltage sag information; determining a high-frequency modeling mode of each node based on the voltage sag information; analyzing the high-frequency component, and determining a target frequency band; in the target frequency band, determining the corresponding node as a second target node based on an analysis result of the high-frequency operation model; and obtaining a stability evaluation result of the target power grid based on the first target node, the second target node and the topological information, and at least adjusting the switching group number of the parallel capacitor group of the target power grid according to the stability evaluation result. The power grid voltage stability assessment method and system provided by the invention can accurately assess the power grid voltage stability and provide an accurate basis for the control of the power grid voltage.

A power converter includes switching section, tuning section, and rectification section. The tuning section includes transformer with a primary inductance and a secondary inductance and a primary series capacitor connected in series with a primary winding and a secondary series capacitor connected in series with a secondary winding. The primary series capacitor is selected with a resonant frequency with the primary inductance and the secondary series capacitor is selected with the resonant frequency with the secondary inductance. The tuning section includes a resonant tank with a primary parallel capacitor connected in parallel with the primary series capacitor and the primary winding and a primary resonant inductor connected between the switching section and a connection to the primary parallel capacitor. An input impedance of the resonant tank at a switching frequency is below a frequency intersecting an open circuit input impedance and a short circuit input impedance of the resonant tank.

Single band and multiband wireless antennas are an important element of wireless systems. Competing tradeoffs of overall footprint, performance aspects such as impedance matching and cost require not only consideration but become significant when multiple antenna elements are employed within a single antenna such as to obtain circular polarization transmit and / or receive. Accordingly, it would be beneficial to provide designers of a wide range of electrical devices and systems with compact single or multiple frequency band antennas which, in addition to providing the controlled radiation pattern and circular polarization purity (where required) are impedance matched without substantially increasing the footprint of the antenna and / or the complexity of the microwave / RF circuit interfaced to them, whilst supporting multiple signals to / from multiple antenna elements in antennas employing them. Solutions present achieve this through provisioning one or more capacitive series reactances discretely or in combination with one or more shunt capacitive reactances.

The invention relates to the technical field of high-voltage dry-type reactive power compensation, and discloses an underground mining high-voltage dry-type reactive power compensation device. Comprising a dry-type iron core filter reactor module, a high-voltage self-healing parallel capacitor module, an intelligent measurement and control protection integrated module, a heat dissipation dustproof adaptive adjustment module, a high-voltage insulation wiring terminal group, a fault positioning and early warning module and a remote monitoring communication module. All the modules are integrated into a whole through modular design. According to the invention, a modular integrated design is adopted, each functional module is uniformly arranged in the mining explosion-proof shell to form a uniform grounding loop, the shell meets the explosion-proof standard, the protection grade reaches IP65, and the high-grade insulation design of each module is matched, so that the underground high-dust, high-humidity and explosive environment is effectively adapted; the problems that a traditional device is large in potential safety hazard and poor in adaptability are thoroughly solved, and the safety and reliability of the device are remarkably improved.

The invention discloses a cable outer sheath fault detection method considering signal attenuation, and the method comprises the steps: S1, building a detection model of a clinging type cable outer sheath, and enabling the detection model to take two parallel cable metal sheaths as signal transmission lines; s2, establishing a distributed parameter model, wherein the distributed parameter model comprises a series resistor, a series inductor, a parallel conductor and a parallel capacitor per unit length; s3, establishing a shunt capacitance calculation model and calculating total shunt capacitance; s4, building a signal attenuation amplitude calculation model, evaluating the attenuation degree of the detection signal, and judging the applicability of the detection signal according to the attenuation degree; and S5, on the premise of judging that the signal is applicable, injecting a traveling wave signal into the cable metal sheath, and positioning a damage point of the cable outer sheath based on the reflected signal. According to the method, the problems that the fault detection precision is low and the signal applicability cannot be evaluated in advance due to serious signal attenuation in the tightly laid cable tunnel are solved, and the detection accuracy and reliability are remarkably improved.

The application provides a non-continuous three-phase rectifier adjustable power decoupling method, and relates to the field of power electronics. The method is characterized in that a capacitor equivalent circuit is connected in parallel to the DC side of a three-phase PWM rectifier, the capacitor equivalent circuit is composed of a first capacitor connected in series with an active negative capacitor circuit, and a digital signal controller is used to sample the relevant voltage and current signals of the AC side and the DC side, and the active negative capacitor capacitance is adjusted by controlling the switching tube, so that the equivalent capacitor circuit can be flexibly adjusted. The application does not require an additional DC power supply, the capacitance and inductance of the passive device used are small, and the volume advantage is significant. The closed-loop control has high precision and equivalent inhibition effect as the traditional large capacitor. The equivalent capacitance is adjusted only by software, the external physical structure does not need to be changed, and the adjustment range is wide. The preset DC side voltage fluctuation amplitude can be calculated and adjusted automatically, different unbalanced working conditions can be adapted, the fluctuation suppression demand can be met, different working modes can be switched according to the AC side working condition, and the application is not continuously operated, so that the switching loss is lower.

The utility model relates to a sheet net type guardrail for a parallel capacitor device, and belongs to the technical field of capacitor guardrails. Comprising an isolating switch operating mechanism, two access doors, a plurality of isolating net frames, three reinforced isolating net frames, an isolating switch frame and a discharge coil frame, the isolation switch frame and the discharge coil frame are arranged on two sides of a capacitor in a one-to-one correspondence manner and are connected with the two reinforced isolation net frames in a one-to-one correspondence manner, the isolation switch operation mechanism is mounted on the other reinforced isolation net frame, the other reinforced isolation net frame is connected with the isolation switch frame, and the discharge coil frame is connected with the discharge coil frame. And the access door, the isolation net frame and the reinforced isolation net frame are wound to form an annular guardrail, and the capacitor, the isolation switch frame and the discharge coil frame are surrounded in the annular guardrail. The utility model has the advantages of simple structure, easy manufacture, convenient disassembly, convenient installation, strong perspectivity and high strength, and is favorable for resisting the invasion of external force.

The application discloses a kind of Buck converter operating state online detection methods under CCM mode, parallel a known capacity capacitor at the output of Buck converter, collect the output voltage ripple before parallel capacitor and the output voltage ripple after parallel capacitor, then combine the average value of output voltage, the parameter of output filter capacitor can be calculated, and the performance of switching power supply will not be affected by parallel capacitor;Without additional excitation auxiliary measurement, without disassembling power supply, the operating state of Buck converter can be detected online, and Buck converter is not impacted in any way;In the long-term operation process of Buck converter, the working state and aging condition of Buck converter can be judged according to the parameter of capacitor, to achieve the purpose of Buck converter fault detection.

The invention discloses an LC interface filter which comprises a parallel capacitor and a series inductor with eddy current magnetic loss, and the structural design of the inductor (10) enables the eddy current magnetic loss to be far larger than magnetic hysteresis loss; the inductor is composed of a magnetic material tube (12), an electric conductor (14) is wound outside the magnetic material tube, and the magnetic material tube and the electric conductor are isolated through an insulating sheet (16).

To provide a light control sheet which can increase the reliability to application of high voltages.SOLUTION: A light control sheet 10 includes: a light control layer 20 including a liquid crystal composition; and first and second transparent electrode layers 31 and 32 that are a pair of transparent electrode layers in which the light control layer 20 is to be inserted. At a frequency of 10 Hz, the parallel capacitance per unit area of the light control sheet 10 is not less than 0.20 nF / cm2 and not more than 0.37 nF / cm2. The thickness of the light control layer 20 is 20 μm to 35 μm, and the area of the light control layer 20 is 0.135 m2 to 1.5 m2.SELECTED DRAWING: Figure 2

The embodiment of the application discloses a parameter acquisition method of an oscillation waveform detection system, relates to the technical field of power system control, and accurately acquires the equivalent resistance value, the equivalent inductance value and the equivalent distributed capacitance value of a winding of a transformer to be measured, the output voltage of a high-voltage direct-current power supply, the maximum input voltage of a data acquisition module, the maximum charging current value allowed by a charging detection loop and the like, and based on the indexes, the first capacitance value of a parallel capacitor, the second capacitance value of a voltage division capacitor, the third capacitance value of a measurement capacitor and the resistance range of a current limiting resistor in the oscillation waveform detection system are acquired, the uncertainty caused by empirical design is avoided, the quality of generated oscillation waveforms is ensured to be stable and controllable, consistent and reliable detection results on transformers of different capacities and voltage grades are ensured, and the accuracy and universality of the oscillation wave detection method in practical application are improved.

A frequency synthesis circuit includes a first inductor coupled to receive a first input signal at an input frequency, and a second inductor coupled to receive second input signal at the input frequency and out-of-phase relative to the first input signal. The circuit has first and second transistors with control terminals coupled to the first and second inductors, respectively. A first resonant tank of an inductor in parallel with a capacitor is coupled between a power supply terminal and the first transistor. A second resonant tank of an inductor in parallel with a capacitor is coupled between the power supply terminal and the second transistor. The first and second resonant tanks are tuned to a selected harmonic of the input frequency. An injection-locked oscillator has inputs coupled to the first and second transistors.

The invention discloses an antenna tuning matching network circuit of a mobile platform short wave shunt-fed antenna and a tuning method of the antenna tuning matching network circuit. The circuit comprises a series inductor L1, a series capacitor C2, a parallel inductor L2 and a parallel capacitor C1, one end of the series inductor L1 is connected with one end of a shunt-fed antenna, the other end of the series inductor L1 is connected with one end of the series capacitor C2, and the other end of the series capacitor C2 is connected with one end of a power amplifier; the common end of the series inductor L1 and the series capacitor C2 is connected to one end of the parallel inductor L2 and one end of the parallel capacitor C1. The other end of the shunt inductor L2 is connected with the other end of the shunt capacitor C1, and the common end is connected to the other end of the shunt-fed antenna and the other end of the power amplifier. According to the input impedance admittance data of the mobile platform short-wave shunt-fed antenna, tuning is carried out in multiple frequency band ranges. According to the invention, perfect matching of the short-wave shunt-fed antenna which shows strong capacitance in a high frequency band and even has a second resonance point is realized, so that the tuning capability of the antenna tuner is improved, and the communication effect is improved.

The invention relates to the technical field of capacitor reactive compensation, and provides an adjustable capacitor reactive compensation system and a control method thereof.The system comprises a control unit, a driving unit, a switching unit, a capacitor unit, an acquisition unit, an alarm unit and a data storage unit; the control unit calls a data model of the data storage unit in real time for comparative analysis according to voltage, current and temperature information fed back by the acquisition unit and switching frequency information fed back by the switching unit, analyzes whether compensation operation is needed or not, and controls the switching unit to change and adjust an access combination mode of the capacitor according to an analysis result; meanwhile, operation of a system protection function is carried out according to the type of a system fault, and alarm information is transmitted to an alarm unit for alarm processing. According to the invention, the defect that a single series capacitor compensation or a parallel capacitor compensation cannot be selected and can only be fixed is overcome, the compensation of different capacities is realized, and the requirements of different customers are met.

The utility model discloses an intelligent power supply system, and specifically relates to the power supply management field, the intelligent power supply system comprises an input filter network, the input filter network comprises a resistor R7, one end of the resistor R7 is connected with an input terminal VIN, the other end of the resistor R7 is successively connected with three parallel capacitors, the three parallel capacitors are respectively a capacitor C2, a capacitor C3 and a capacitor C4, and the capacitor C2, the capacitor C3 and the capacitor C4 are connected with the input terminal VIN. The other ends of the three parallel capacitors are all connected with a ground wire GND and are used for filtering ripples of the input end VIN and stabilizing voltage; and the boost power conversion module comprises an inductor L1, one end of the inductor L1 is connected with an output node of the input filter network, and the other end of the inductor L1 is connected with a boost node N1. By constructing a multi-stage coupling control access including input filtering, boost control, overvoltage clamping, current sampling and output feedback regulation, a quick response to power disturbance, load fluctuation and an abnormal state and a self-adaptive power supply regulation mechanism are realized.

The invention belongs to the technical field of integrated circuits, and particularly relates to a millimeter wave broadband low-noise amplifier. The millimeter wave broadband low-noise amplifier comprises a broadband input matching network, a first-stage cascode amplification stage, a first-stage inter-stage matching network based on three-coil coupling, a second-stage differential cascode amplification stage, a second-stage inter-stage matching network based on an asymmetric resonant cavity, a third-stage differential cascode amplification stage and a broadband output matching network. The broadband input matching network comprises a source electrode degeneration inductor and a series-parallel capacitor inductor network, and good conjugate matching and noise matching can be achieved at the same time within the broadband range. According to the invention, a three-coil coupling architecture and an asymmetric resonant cavity architecture are respectively adopted in the design of an inter-stage matching network, and higher gain and lower gain ripple and noise coefficient are realized in a broadband range.

The invention discloses a self-healing parallel capacitor aging test device and method for an AC power system. The method comprises the following steps: S1, preparation before test; s2, carrying out a first-stage aging test; s3, carrying out a charge-discharge cycle test; s4, performing a second-stage aging test; and S5, detecting after the test. According to the self-healing parallel capacitor aging test device and method for the alternating-current power system, automatic control over the whole test process is achieved, it is guaranteed that test conditions meet the national standard requirement, the influence and closing impact on a power grid in the test process are eliminated, the accuracy and reliability of a test result are improved, and the test efficiency is improved. A standardized method is provided for performance evaluation of the capacitor, and the problems that an existing test device is low in integration and automation degree, poor in test precision, large in power grid influence and insufficient in safety protection are solved.