124 results about "Reactance" patented technology

Compensation schemes for a modular jack are provided according to the present disclosure. The compensation schemes advantageously include a first coupling of compensating crosstalk between a first pair of conductors and a second pair of conductors and a second coupling of compensating crosstalk between only a first conductor of the first pair of conductors and only a first conductor of the second pair of conductors, wherein the first and second couplings of compensating crosstalk are of opposite polarities. In exemplary embodiments, the first coupling of compensating crosstalk may be provided by a circuit board, such as a flexible circuit board including a plurality of interconnection elements, e.g., capacitors, for providing the first coupling of compensating crosstalk. Alternatively, the first coupling of compensating crosstalk may be provided by a plurality of plug interface contacts associated with the first and second pairs of conductors. Similarly, the second coupling of compensating crosstalk may be provided either by a circuit board associated with the first and second pairs of conductors or by a plurality of rear wire connection terminals associated with the first and second pairs of conductors.

The invention discloses a control method of a modularization multi-level converter based on an equivalent circuit model. The modularization multi-level converter is provided with six alternating current output ends and six converting reactances. It is known that two alternating current output ends of each phase are isoelectric points according to symmetry analysis, and the isoelectric points can be virtualized to be in short circuit in the theoretical analysis, therefore, the two converting reactances of each phase are in a parallel connection relation and can be combined into a reactance so as to obtain the equivalent circuit model of the modularization multi-level converter, wherein the equivalent circuit model has three alternating current output ends and three converting reactances, and is in a structure similar to the traditional voltage source converters of a two-level converter and the like, therefore, the control method of the traditional voltage source converters can be directly applied to the modularization multi-level converter.

A database is compiled of values of the frequency fNM corresponding to the minimum reactance Z″MIN (Nyquist minimum) versus temperature TL over a selected range of temperatures for a probe immersed in a sample of the fluid to be monitored and excited by an a.c. voltage and the frequency swept over a range to cover both bulk fluid and electrode interface impedance characteristics. The probe is then excited in situ and the temperature measured. The Nyquist minimum is then determined from the database and the current measured on the low frequency (interfacial) side of the Nyquist minimum. The angle Θ of the rate of change of resistance Z″ with respect to resistance Z′ and magnitude of the impedance ZS is then determined from the current measurement; and, the fluid condition Ψ determined from a previously compiled database of values of Ψ, ZS and Θ.

The invention relates to a method of 110 / 220 kV transformers' neutral point grounding via a small reactance. According to the invention, a movable mold real-time simulation technology based on an RTDS is employed to calculate highest overvoltages of neutral points of 110 / 220 kV transformers and current limiting capacity of a small reactance after grounding of the 110 / 220 kV transformers via the small reactance; influence factors of a current and a voltage of the neutral point after the transformers' neutral point grounding via the small reactor are studied comprehensively; and a selection method for a grounding small reactance resistance, a theoretical research for realizing the method and practical application thereof are described.

The invention relates to a test method of reactance parameters of a surface permanent magnet synchronous motor, and the test method comprises the following steps: 1) test devices are selected and the preparation is carried out, 2) the test process is carried out, 3) test data is analyzed, 4) the calculation is carried out according to the following Ld and Lq; the steps for selecting the test devices are as follows, a variable frequency meter, a current meter and a voltage meter are selected; the steps of the test process are as follows, when in test, a rotor is slowly moved, the maximum and the minimum of the current which is extracted by the current meter are observed, the voltage value of a power supply is recorded simultaneously; the steps for analyzing the test data are as follows, the main test data which is the resistance and the reactance value of the motor is calculated by a reactance parameter expression; the Ld and Lq calculation steps are as follows, the direct-axis synchronous reactance Ld and the quadrature-axis synchronous reactance Lq are measured for the permanent magnet synchronous motor with the sine wave power supply. Compared with the methods of the prior art, the method can more conveniently measure the reactance parameters of the surface permanent magnet synchronous motor by the simple test devices, thereby having certain economic benefit.

A combination of frequency and time division multiplexed signals communicates using bursts of higher frequency sinusoidal waves superimposed upon the alternating current in a two-wire power distribution network. A synchronization pattern precedes data, all bursts having the same frequency to overcome problems caused by varying reactances, and all bursts being confined within negative half-cycles of the AC power. Such networks minimize the amount of wire needed to connect large numbers of devices to a common controller while covering large distances, and requiring no particular connection pattern or terminations, whether near the surface, above ground, or in deep earth wells. In an irrigation system they accommodate at once solenoid valves and distributed environmental sensors. Landscape changes that would otherwise require new wiring to accommodate new irrigation zones are facilitated by merely tapping into the two-wire communications lines at the nearest accessible point. Outdoor lighting controls and security sensors are easily accommodated.

A device comprising at least two controllable reactance elements (1) arranged to compensate a single phase-to-earth fault current in a power network with a power transformer (3). The at least two controllable reactance elements (1) are each connected with one side to two different voltages of a three phase voltage source which is synchronous with the power network, and that the reactance elements with their other side are jointly connected to the neutral (N) of the power network or its equivalent. The reactance elements are individually controllable by a control unit (2) designed to control the neutral voltage of the power transformer (3) or its equivalent with respect to amplitude and phase in relation to the power transformer's own voltage system. A method in relation to the device is also disclosed.

The invention discloses a high voltage transmission line power taking method and device based on capacitive reactance matching shunt control. An air gap magnetic core is inserted into a power transmission cable, and a matching capacitor C with certain capacitance value is connected with the secondary winding of the magnetic core to form a damping branch. On the power transmission cable on both ends of the magnetic core, a load is connected with the high-voltage power transmission cable through a shunt line through a clamp to form an energy taking branch. By setting the capacitance value to enable the equivalent excitation inductor of the magnetic core to carry out parallel resonance, the equivalent impedance of the damping branch is significantly increased, and the bus current is divided into the energy taking branch. The current of the energy taking branch is increased, and the current of the damping branch is decreased to provide high-power electrical energy through the energy takingbranch. According to the invention, the method and device are not affected by weather and climate; the overall power taking volume is small, so that the installation is easy; the device can take a large amount of power from a transmission bus, and can continuously and stably provide sufficient power for the online monitoring equipment of a transmission line; and the reliability of the online monitoring equipment of the transmission line is improved.

The embodiment of the invention discloses a method and device for measuring parameters of the inner potential and the reactance of a synchronous generator and relates to the technical field of power system synchronous phasor measurement. The method comprises the steps that a generator end voltage phasor U( ), a generator end current phasor I( ), a generator power angle delta and a generator end voltage value U of the synchronous generator are measured and obtained through a synchronous phasor measuring device; a generator end power factor angle phi is generated according to the generator end voltage phasor U( )and the generator end current phasor I( ); the inner potential amplitude Eq of the synchronous generator is determined according to the generator power angle delta, the generator end voltage value U and the generator end power factor angle phi. The method and device can solve the problem that the inner potential amplitude is calculated through an indirect electric method currently, the result is not accurate, and large errors exist.

The invention discloses a differential protection hardware circuit with percentage differential and an implementation method of the differential protection hardware circuit. The differential protection hardware circuit comprises a data collection module, a data processing module, a protection algorithm module and a relay, wherein the data collection module is used for collecting input and output three-phase current signals of a reactance transformer, and taking the collected input and output three-phase current signals of the reactance transformer as an data input of the data processing module; the data processing module is used for carrying out filter operations on the input and output three-phase current signals of the reactance transformer, and taking the filter operation result as the input of the protection algorithm module; the protection algorithm module is used for carrying out a percentage differential protection design on the current signals input by the data processing module, and taking the final actuating signal as the input of the relay; the relay carries out an action according to the signal input by the protection algorithm module; if the input signal is high, the relay is closed; and if the input signal is low, the relay is closed. According to the differential protection hardware circuit, the percentage differential protection function is realized; and the reliability and the processing speed are greatly improved.

Virtual inductive reactance regulator and control method for realizing reactive power equalization of parallel inverter. Virtual inductive reactance regulator consists of subtractor, integrator and adder. The input of the subtractor is the output reactive power of the inverter and the rated reactive power of the inverter, and the absolute error of the output reactive power; The input of the integrator is the absolute error of reactive power and the adaptive part of the output virtual inductive reactance. The input of the adder is the output of the integrator and the reference virtual inductivereactance, and the output virtual inductive reactance. The virtual reactance regulator is installed in the local controller of the inverter, and the local controller and the central controller are interconnected through a low bandwidth communication line. The invention introduces a virtual inductive reactance into each inverter of a low-voltage microgrid and adds a virtual inductive reactance regulator, Reactive power is used to adjust the virtual inductance, which can achieve reactive power equalization without measuring line impedance parameters to achieve line impedance matching. Additional communication lines are not needed between inverters, and the plug-and-play characteristics of micro-grid inverters are preserved.

A transformer is provided between a power supply and a load, and includes a front stage circuit and a rear stage circuit each having a function of performing switching so as to alternately invert a polarity of output relative to input. The transformer further includes: a series unit provided in at least one of both circuits and composed of a pair of reactance elements connected in series to each other via a connection point; and a switch device which, with both ends of the series unit serving as a first port, causes a part between one end of the series unit and the connection point, and a part between the other end of the series unit and the connection point, to serve as a second port alternately through switching while inverting a polarity, and executes power transmission from the first port to the second port or vice versa.

An antenna structure includes a metal mechanism element, a ground element, a feeding radiation element, a coupling element, a dielectric substrate, and a switchable circuit. The metal mechanism element has a slot. The feeding radiation element extends across the slot. A coupling gap is formed between the feeding radiation element and the coupling element. The feeding radiation element and the coupling element are disposed on the dielectric substrate. The switchable circuit includes a first metal element, a second metal element, a reactance element, a capacitor, and a diode. The first metal element is coupled to the coupling element. The reactance element is embedded in the first metal element. The second metal element is coupled through the capacitor to the ground element. The diode is coupled between the first metal element and the second metal element. The diode is turned on or off according to the control voltage difference.

A magnetic resonance type isolator includes a ferrite; a connection conductor that is arranged on the ferrite and includes first, second and third ports; a permanent magnet that applies a direct current magnetic field to the ferrite; a capacitor (or an inductor) that defines a first reactance element; and a capacitor (or an inductor) that defines a second reactance element. A main line arranged between the first port and the second port of the connection conductor does not resonate, an end portion of a sub-line that branches off from the main line serves as the third port, and a wave reflected from the sub-line is modulated so that its phase is shifted by 90° or about 90° at an intersection of the connection conductor. One of the capacitors is connected to the third port and the other capacitor is connected between the first port and the second port.

A device comprising at least two controllable reactance elements (1) arranged to compensate a single phase-to-earth fault current in a power network with a power transformer (3).The at least two controllable reactance elements (1) are each connected with one side to two different voltages of a three phase voltage source which is synchronous with the power network, and that the reactance elements with their other side are jointly connected to the neutral (N) of the power network or its equivalent.The reactance elements are individually controllable bya control unit (2) designed to control the neutral voltage of the power transformer (3) or its equivalent with respect to amplitude and phase in relation to the power transformer's own voltage system.A method in relation to the device is also disclosed.

A reactance is introduced into a flow path of axial currents in an induction logging tool. The reactance may be a capacitor or an inductor. A transmitter antenna is operated at a frequency defined by a cutoff frequency related to the reactance.

A self-tuning impedance-matching microelectromechanical (MEMS) circuit, methods for making and using the same, and circuits including the same are disclosed. The MEMS circuit includes a tunable reactance element connected to a first mechanical spring, a separate tunable or fixed reactance element, and an AC signal source configured to provide an AC signal to the tunable reactance element(s). The reactance elements comprise a capacitor and an inductor. The AC signal source creates an electromagnetically energy favorable state for the tunable reactance element(s) at resonance with the AC signal. The method of making generally includes forming a first MEMS structure and a second mechanical or MEMS structure in / on a mechanical layer above an insulating substrate, and coating the first and second structures with a conductor to form a first tunable reactance element and a second tunable or fixed reactance element, as in the MEMS circuit.

The invention discloses a method for judging winding deformation based on short-circuit reactance, and the method comprises the following steps of step 1, establishing a winding equivalent circuit model; step 2, establishing a winding system parameter identification technology; step 3, obtaining the relationship between the changes in the winding system parameters and fault factors; and step 4, carrying out intelligent detection of winding deformation. In the step 1 above, the winding equivalent circuit model is created according to the needs of judgment of detecting winding deformation, and the influence rule of the physical form of the winding on the distribution parameters of winding RLC and other parameters is analyzed. The frequency sweep impedance method is a new type of transformerwinding deformation test method, which combines the characteristics of test methods on the market, has a great breakthrough in test principles, and also has the advantages such as simple and portabletest equipment, high sensitivity and clear criteria. With the method, the frequency sweep impedance curve and short-circuit impedance value of the transformer can be obtained in one test, which effectively reduces the errors caused by multiple times of wiring.

The invention provides an inductive reactance decreasing linear controllable inductor. The inductor is characterized by comprising an insulated vessel (G11), a conducting liquid (G31), a floating body (G21), a common electrode (G51), a winding rod (L10), an inductance coil (L1), an electromagnetic coil (G41), a controlled path first node (O+), a controlled path second node (O-), a control terminal first node (P+) and a control terminal second node (P-). An electronic circuit comprises the controllable inductor. Electromechanical equipment comprises the controllable inductor. The inductor has long contact life and good isolation, is low in cost and can be applied to high-power circuits, such as weak-current power circuits, power circuits and ultrahigh-voltage power circuits.

A control circuit (16) is configured to detect the impedance P1 of a load (3) and control each of the reactance value L1 of a first variable reactance element (12), the reactance value L2 of a second variable reactance element (14), and the phase shift amount φ of a phase shifter (15) on the basis of the detected impedance P1. Consequently, impedance matching can be achieved even with the phase shifter (15) that performs discrete phase shift control.

In one embodiment, a method of matching an impedance is disclosed. A matching network includes an electronically variable reactance element (EVRE) comprising discrete reactance elements and corresponding switches. For a determined parameter, potential new positions for the EVRE are determined, the potential new positions having differing effectiveness in causing an impedance match between an RF source and a plasma chamber. The discrete reactance elements of the EVRE that are currently restricted from switching are determined. A preferred position for the EVRE is determined as being the one of the potential new positions that provides greatest effectiveness in providing an impedance match while also not requiring switching in or out of any of the discrete reactance elements that are currently restricted from switching.

A system includes a power source, a transmitter circuit, a conductor, and a receiver circuit. The transmitter circuit is supplied by the power source and wirelessly supplies the receiver circuit via the conductor. The conductor includes a plurality of distributed capacitances coupled in series with the conductor. The receiver circuit includes a primary coil and a secondary coil. The primary coil has at least two turns and includes a plurality of distributed capacitances. The transmitter circuit includes an Open Loop Reactance Matching (OLRM) control circuit, a first inverter, a second inverter, and a third inverter. The OLRM control circuit controls the first inverter to generate a high frequency AC voltage to be supplied to the conductor. During wireless power transfer, the OLRM control circuit performs reactance matching by controlling the second and third inverters to maintain the transmitter voltage and current in phase without requiring any feedback sensing.

According to the reactance target simulator disclosed by the invention, a system main control unit is used for receiving signal parameter setting and outputting a control instruction to an interface control assembly, and the interface control assembly analyzes the control instruction and outputs a control code to a narrowband source module, a baseband source module and a frequency expansion module respectively; the narrowband source module outputs a CD signal, a plurality of diversity signals and two reference signals; the baseband source module receives the control code and one path of reference signal output by the narrowband source module, and outputs a baseband signal; the frequency expansion module receives the control code, the baseband signal output by the baseband source module and the other path of reference signal output by the narrowband source module, and outputs one path of frequency source signal; and a combining assembly receives diversity signals output by the narrowband source module and / or frequency source signals output by the frequency extension module, and outputs amplitude comparison signals and interferometer signals. According to the invention, diversified signal forms and high-fidelity, high-precision and stable radar signals can be generated in real time.

A variable resonator that comprises a loop line (902) to which two or more switches (903) are connected and N variable reactance means (102) (N≧3), in which switches (903) are severally connected to different positions on the loop line (902), the other ends of the switches are severally connected to a ground conductor, and the switches are capable of switching electrical connection / non-connection between the ground conductor and the loop line (902), the variable reactance blocks (102) are severally settable to the same reactance value, and the variable reactance blocks (102) are electrically connected to the loop line (902) as branching circuits along the circumference direction of the loop line (902) at equal electrical length intervals.

The invention relates to a dynamic voltage-adjustment reactive compensation technology, in particular to a variable series-connection reactance dynamic voltage-adjustment reactive compensation method and device. The variable series-connection reactance dynamic voltage-adjustment reactive compensation method includes the steps of setting a series-parallel connection assembly for a variable electric reactor and a capacitor and connecting the series-parallel connection assembly into a load side inlet; detecting the voltage offset and operation conditions of the outlet end and the power factor of the inlet end of the assembly in real time; dynamically controlling the parameters of the variable electric reactor and the capacitor in series-parallel connection according to the voltage offset and operation conditions of the load side and the power factor on a power grid side, and enabling the voltage on the load side to reach the standard and the power factor on the power grid side to be improved. The variable series-connection reactance dynamic voltage-adjustment reactive compensation device comprises a series-parallel connection unit for the variable electric reactor and the capacitor, a load voltage offset and power grid reactive vacancy detection unit, a dynamic voltage-adjustment and reactive power compensation control unit, a dynamic voltage-adjustment and reactive power compensation execution unit and an element and device protecting unit. The variable series-connection reactance dynamic voltage-adjustment reactive compensation method and device can be used for controlling low voltage, improving electricity quality, reducing losses, saving energy and improving power supply reliability and electricity utilization rate, and have the advantages of being safe, being environmentally friendly, saving energy and increasing the effect.

The invention discloses a reactance arrangement method for limiting short-circuit current of a power grid and a related device, and the method comprises the steps: carrying out the load flow calculation of a preset power system model, and obtaining the operation state parameters of the power grid; on the basis of an equivalent voltage source theorem, calculating the short-circuit current of each node of the power grid according to the operation state parameters; selecting an overproof short-circuit current from the short-circuit current through a short-circuit current threshold value; and calculating series reactance according to the maximum standard-exceeding short-circuit current, and arranging the series reactance on a branch where a node corresponding to the maximum standard-exceeding short-circuit current is located. The technical problem that the reactance arrangement scheme is poor in effectiveness and economical efficiency due to the fact that impedance selection and arrangement in the prior art are not targeted is solved.