117 results about "Reactance" patented technology

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.

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.

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.

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.

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 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.

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.

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.

The invention relates to a small-size large-capacity voltage-withstanding device used for a GIS test. The device is connected with an external power supply and a to-be-tested GIS device respectively to achieve the voltage-withstanding experiment of the GIS device; the small-size large-capacity voltage-withstanding device includes a whole movement chassis, a reactance module, a capacitance module and an isolation impedance module, wherein the reactance module, the capacitance module and the isolation impedance module are arranged on the whole movement chassis; the reactance module, the capacitance module and the isolation impedance module are all metal closed modules insulated with SF6 gas and are connected together to form a series resonance voltage boosting circuit, the input end of the reactance module is connected with the external power supply, the output end of the reactance module is connected with the input end of the isolation impedance module, and the output end of the isolation impedance module is connected with the capacitance module and the to-be-tested GIS device respectively. Compared with the prior art, the device has the advantages of being large in capacity, small in size and movable, having the partial discharge measurement function of the impulse current method and the like.

The invention relates to a flexible DC power module test system and method. The test system comprises a voltage conditioning module, a reactance adjusting module, a switch module, a sampling module and a control module. The voltage conditioning module, the reactance adjusting module, the switch module and the sampling module are connected with the control module; the voltage conditioning module, the reactance adjusting module, the switch module, the sampling module and the control module are all connected with a tested power module; the switch module is also connected with the reactance adjusting module; and the voltage conditioning module is used for connecting an external power supply. The control module is used for acquiring test parameters and adjusting working parameters of the voltage conditioning module, the reactance adjusting module and the switch module and operating parameters of the tested power module according to the test parameters; and the control module is also used for obtaining the sampling information sent by the sampling module, obtaining a test result according to the sampling information and outputting the test result. The flexible direct-current power module test system can meet different test requirements without secondary wiring, and is beneficial to improving the test working efficiency.

The invention discloses an adaptive zero sequence current quick-break protection method, which comprises the following steps of (1) calculating positive sequence reactance XC1, negative sequence reactance XC2 and zero sequence reactance XC0 of a to-be-measured line in real time through microcomputer protection; (2) calculating real-time grounding short-circuit current I0 at a tail end of the lineaccording to the positive sequence reactance XC1, the negative sequence reactance XC2 and the zero sequence reactance XC0 calculated in the step (1) and storing the short-circuit current I0 into a memory RAM; and (3) judging whether line fault current IM measured through microcomputer protection is greater than the real-time grounding short-circuit current I0, stored in real time, at the tail endof the line in the RAM or not, if the judgment result is ''yes'', making a protection device act, or else, returning to the step (1). According to the adaptive zero sequence current quick-break protection method, a fault can be instantaneously removed through the protection device when a short circuit appears in the line, so that the sensitivity of protection is effectively improved.

The invention discloses an active multi-reactance compensation output topological structure based on a switch E-type mode power amplifier, which mainly comprises an equivalent current source, a drain bias network, a parallel output capacitor, a reactance compensation network and a terminating load, and is characterized in that the reactance compensation network comprises an LnCn series resonance circuit and an Ln + 1Cn + 1 parallel resonance circuit, n is the order of the reactance compensation network, and n is the order of the reactance compensation network; and determining according to an actual circuit design. Wherein the E-type mode is mainly controlled by an output capacitor Cout, a compensation inductor LB and a terminating load R. Compared with a traditional impedance matching circuit, the working bandwidth of an output matching circuit of the impedance matching circuit can be effectively widened, and compared with a traditional broadband design method, the design structure is simple, implementation is easy, reliability is high, and the impedance matching circuit can be applied to design of a broadband efficient power amplifier.

A high-frequency switch includes an input interface configured to receive a high-frequency signal; an output interface configured to output the high-frequency signal to outside; and a reactance switch inserted between the input interface and the output interface. The reactance switch includes a plurality of reactance circuits connected in a cascade arrangement between the input interface and the output interface. Each of the plurality of reactance circuits is configured to form a common passband for the high-frequency signal based on a reactance of a respective predetermined values, and at least one of the reactance circuits is a variable reactance circuit having a reactance which changes in response to a control signal input from the outside so that the passband of the variable reactance circuit changes.