418 results about "Dc resistance" patented technology

The invention discloses a method and a system for compensating different-frequency current errors of a low-voltage current transformer, and belongs to the technical field of error measurement of electric energy metering equipment. The method comprises the following steps: measuring the magnetic conductivity of a low-voltage current transformer CT iron core under power frequency and different frequency current, and calculating to obtain low-voltage CT equivalent circuit excitation impedance parameters under the magnetic conductivity corresponding to different frequency circuits; measuring to obtain the direct current resistance of the low-voltage CT secondary winding, and calculating to obtain the excitation current value under each frequency calibration range point based on the direct current resistance; and calculating a current error value of the measuring range point under each frequency based on the excitation current value, calculating a pilot frequency error compensation coefficient of the measuring range point under each frequency based on the current error value, and compensating the abnormal current error of the low-voltage CT by using the pilot frequency error compensation coefficient. According to the invention, large-scale and high-efficiency utilization of pilot frequency current is facilitated to carry out low-voltage CT live calibration error verification, and the metering performance of the low-voltage CT in the commissioning process is accurately judged.

The invention discloses a lithium battery dynamic heat generation power calculation method for stabilizing new energy power fluctuation, and belongs to the technical field of power system energy storage. According to the method, clustering analysis is carried out on new energy historical output data based on an improved K-means algorithm of a contour coefficient method, and a typical output scene is extracted; taking the condition that the fluctuation rate of the new energy grid-connected power meets the fluctuation rate constraint as an optimization target, performing decomposition and reconstruction on the typical output scene by adopting an adaptive wavelet packet decomposition algorithm, and determining an expected grid-connected power instruction; based on the expected grid-connected power instruction, rated power configuration and rated capacity configuration are considered, and an energy storage configuration model is constructed and solved; and solving a charge state calculation formula at each moment in the operation cycle, respectively constructing a function relation expression of dynamic change of the direct current resistance and the working current with the charge state, and further calculating the dynamic heat generation power of the lithium battery through a Bernardi heat generation rate formula. And characterizing a characteristic mapping relation among the dynamic heat source, the charge state and the time through a lithium battery dynamic heat generation formula.

The invention relates to the technical field of electrical performance testing, in particular to a method and system for measuring loss of an inductance winding, and the method comprises the following steps: applying a direct current to a measured inductance winding, synchronously monitoring the temperature, and multiplying a pre-measured direct current resistance value by a direct current value to obtain a direct current loss power value. The direct current is applied to the inductance winding, the temperature is monitored synchronously, the direct-current loss power is obtained by combining the direct-current resistance value and the current value, the temperature curve in the initial stage is extracted, the temperature rise rate is calculated, and therefore the winding heat capacity parameter is obtained, loss measurement can be closely associated with thermal response, and the measurement accuracy is improved. Introduction of a heat capacity factor is added in loss calculation, dynamic characteristics of a winding material on a thermodynamic level can be reflected, instantaneous current with load step change is applied after an inductor is cooled, an instantaneous loss power curve is generated by collecting a voltage sequence and a current sequence at the same time, and loss calculation is not limited to average value or steady state measurement any more.

The invention provides a method for testing breakage of a film covered wire. The method comprises the following steps of: 1, respectively sampling a section of a wire with the length of 1m and a section of a wire with the length of 10m; step 2, respectively measuring weight values and direct-current resistance values of the 1-meter sampling line and the 10-meter sampling line to obtain a weight value G1 of the 1-meter sampling line, a direct-current resistance value R1 of the 1-meter sampling line, a weight value G2 of the 10-meter sampling line and a direct-current resistance value R2 of the 10-meter sampling line; step 3, calculating the direct current resistance change rate according to a formula delta R = {R2 / [R1 * (G2 / G1)]-1} * 100%; 4, when the direct-current resistance change rate delta R is smaller than a set percentage, the wire is judged to be qualified; and when the direct-current resistance change rate delta R is greater than or equal to a set percentage, judging that the wire has the wire breakage defect. According to the invention, the resistance abnormity caused by broken line and non-broken line factors can be effectively distinguished, and the misjudgment rate is reduced; and meanwhile, quantitative line breakage degree evaluation can be realized, and a technical basis is provided for formulating an industrial line breakage detection standard.

The utility model provides an integrally-formed inductor which comprises a magnetic core and at least two coils. The magnetic core is formed by pressing a first forming part and a second forming part; the first forming part and the second forming part are both formed by pre-pressing magnetic powder; the coil arrangement direction is perpendicular to the axis direction of the coils; the second forming part is provided with at least two accommodating grooves; each accommodating groove is configured to accommodate at least one coil; the first forming part comprises an upper pendulum and a middle column for filling a middle gap of the coil; the upper pendulum basically covers the containing groove. The first forming part and the second forming part are pre-pressed and formed by the magnetic powder, then the first forming part and the second forming part are pressed into the magnetic core, and compared with a magnetic core structure which is directly pressed and formed by the magnetic powder, the technical scheme of the utility model can reduce gaps among powder materials and improve the density of the magnetic core, so that the direct-current resistance value of the inductor is reduced; the inductance characteristic is improved.

The invention relates to the technical field of power transmission systems, in particular to a high-voltage direct-current power transmission receiving end tap switch control method, system and device and a medium. An initial tap switch gear is selected from the tap switch gear interval, and the lowest steady-state alternating current system voltage is determined based on the initial tap switch gear; calculating a minimum valve side ideal no-load direct-current voltage according to the minimum steady-state alternating-current system voltage; according to the minimum valve side ideal no-load direct-current voltage and the minimum direct-current resistance, the minimum steady-state direct-current voltage value of the sending end is calculated; calculating the maximum steady-state direct-current voltage value of the sending end based on the maximum alternating-current system voltage and the maximum direct-current resistance; and carrying out iterative adjustment on the tap switch gear based on the lowest steady-state direct-current voltage value of the sending end and the highest steady-state direct-current voltage value of the sending end to obtain an optimal target gear of the tap switch. According to the invention, the optimal control of the tap switch gear is realized, the action times of the tap switch are effectively reduced, and the stability and reliability of a power transmission system are improved.

The invention relates to the technical field of electric power, in particular to a grounding grid state evaluation method and system based on a three-dimensional direct-current resistance matrix, accurately reflects the conduction state of each node of a grounding grid through multi-point measurement, is suitable for fine detection of a complex grounding grid, and particularly is suitable for large-scale water conservancy and hydropower engineering. Fault points or weak links can be positioned; the matrix test comprehensively covers all nodes and paths of the grounding grid, so that no omission is ensured, and a fault or corrosion area of the grounding grid can be accurately positioned; in addition, data provided by testing are rich, deep analysis and trend prediction are facilitated, early warning can be carried out, potential hazards can be found in time, and measures can be taken. The method has the advantages of high anti-interference capability, simplicity and convenience in operation, low cost and suitability for large-scale application, can provide a stable and reliable detection result especially in an electromagnetic complex scene, and is beneficial to long-term monitoring and data analysis.

The invention relates to a transformer direct current resistance tester. The transformer direct current resistance tester comprises a box body, an operation panel and a wiring terminal arranged on the operation panel, the limiting mechanism is used for limiting pulling-out of the detection line; the driving mechanism is used for controlling the limiting mechanism to contact and limit the detection line; the limiting mechanism comprises a limiting plate which is movably arranged on the operation panel; the transmission assembly is used for controlling the movement direction and position of the limiting plate; the wiring port and the detection port are both arranged on the limiting plate, the end part of a detection line penetrates through the wiring port to be connected with the wiring end, and the detection port is used for the detection line to penetrate through; the transmission assembly is used for enabling the detection opening in the limiting plate to move to the position above the end of the detection line. According to the invention, the detection line is limited, so that the effect of improving the safety performance after external power failure is achieved.

The invention discloses a high-performance ship cable and a preparation process thereof, relates to the technical field of cables, and aims to solve the problem that an existing cable is insufficient in environmental adaptability, safety, electromagnetic compatibility and the like, the cable comprises a conductor, an insulating layer, a longitudinal waterproof structure, a shielding layer and a sheath layer from inside to outside, the conductor is of a multi-strand soft copper wire stranded structure, and the copper content of the multi-strand soft copper wire stranded structure is larger than or equal to 99.95%; the DC resistance at 20 DEG C is less than or equal to 0.01724 omega mm / m; the insulating layer is made of cross-linked polyethylene or polytetrafluoroethylene and can resist 1.5 times of rated voltage for 1 minute without breakdown; the longitudinal waterproof structure comprises a water-blocking tape and water-blocking paste; the shielding layer is of a double-layer structure, and the shielding effectiveness is larger than or equal to 60 dB The sheath layer is made of a low-smoke halogen-free flame-retardant material and contains an antioxidant and an ultraviolet light absorber, the preparation process comprises six steps of conductor preparation, insulating layer forming and the like, parameters are accurately controlled, the cable can work at the temperature of-40 DEG C to 85 DEG C, is salt-fog-resistant, waterproof and flame-retardant, is adaptive to the complex environment of ships and warships, and the operation reliability and safety are improved.

To reduce a difference in DC resistance and / or inductance value of each of a plurality of coil conductors, in an inductor including the coil conductors inside.SOLUTION: A layered inductor of the present disclosure includes: an element assembly 10 constituted by laminating a plurality of magnetic layers ML in a lamination direction; external electrodes E1-E4 provided on a bottom face of the element assembly 10; winding parts W1, W2 formed by connecting each end of a plurality of conductors C1, C2, respectively, by a via V, the conductors being disposed in layers different from each other of the element assembly 10; and coils 21, 22 including through holes T1-T4, respectively. The conductors C1, C2 are provided in the same layer, and the area of the conductor C1 in the same layer in plan view is approximately equal to the area of the conductor C2 in plan view. As viewed in a direction crossing the lamination direction, the conductor C1 and the conductor C2 are alternately disposed.SELECTED DRAWING: Figure 2

The invention relates to the technical field of power testing, in particular to multifunctional comprehensive test conversion integrated equipment which comprises a conversion integrated device and test instrument connecting line, a conversion integrated device and a multifunctional comprehensive test line. The conversion integration device and test instrument connecting line is used for connecting the conversion integration device and a test instrument; the conversion integrated device is used for quickly adapting to different test instruments and tested equipment and discharging before and after a test; and the multifunctional comprehensive test line is used for connecting the conversion integrated device and the tested equipment. Test items supported by the device are insulation resistance, dielectric loss capacitance, direct current resistance, transformation ratio and demagnetization tests, all power failure routine test items of the transformer can be completed without replacing a test line, the time of the power failure routine test of the transformer and the frequency of high-altitude operation can be obviously reduced, the working efficiency is greatly improved, and the test cost is reduced. And the safety risk in the test operation process is reduced.

Disclosed are a battery charging method, a battery charging device, and a battery charging apparatus. The battery charging method, comprising: determining a direct current resistance (DCR) curve of a rechargeable battery in response to a charging instruction for the rechargeable battery; obtaining a real-time impedance of the rechargeable battery, and determining an impedance interval in the DCR curve corresponding to the real-time impedance; and determining a current charging strategy for the rechargeable battery according to the impedance interval corresponding to the real-time impedance, and charging the rechargeable battery by using the current charging strategy.

An electronic package is provided, in which an electronic component with a conductive layer on an outer surface thereof is embedded in an encapsulant, where at least one electrode pad is disposed on an active surface of the electronic component, and at least one wire electrically connected to the electrode pad is arranged inside the electronic component, so that the conductive layer is electrically connected to the wire, such that the electrode pad, the wire and the conductive layer are used as a power transmission structure which serves as a current path to reduce DC resistance and improve an impedance issue associated with the supply of power.

To provide a coil component having a plurality of coil elements, and to reduce variations in the DC resistance between the coil elements.SOLUTION: A magnetic coupling coil component 1 comprises: a substrate 10 having a first principal surface 10a and a second principal surface 10b; a first coil conductor 25 facing the first principal surface; and a second coil conductor 35 between the first coil conductor and the second principal surface. The first coil conductor has a first circulation part 25a, a first one end lead-out part 25b extending from one end of the first circulation part to the second surface, and a first other end lead-out part 25c extending from the other end of the first circulation part to the second surface. The second coil conductor has a second circulation part 35a, a second one end lead-out part 35b extending from one end of the second circulation part to the second surface, and a second other end lead-out part 35c extending from the other end of the second circulation part to the second surface. The first cross-sectional area indicating the cross-sectional area of the first one end lead-out part and the second cross-sectional area indicating the cross-sectional area of the first other end lead-out part, are both larger than the third cross-sectional area indicating the cross-sectional area of the second one end lead-out part and the fourth cross-sectional area indicating the cross-sectional area of the second other end lead-out part.SELECTED DRAWING: Figure 1

The invention discloses a positive electrode active material and a preparation method thereof, a positive electrode plate, a battery and a power utilization device, the positive electrode active material comprises an inner core and a coating layer, the inner core comprises a transition metal oxide, the coating layer is formed on the surface of the inner core, the coating layer comprises a polymer containing a silicon-oxygen bond, and the polymer is formed on the surface of the inner core. Based on the total mass of the positive electrode active material, the mass ratio of silicon in the polymer is 0.05%-1%. The positive electrode active material disclosed by the invention has relatively high stability, so that the cycle performance and the direct-current resistance of the battery under high voltage can be improved.

The invention relates to the technical field of motor test equipment, in particular to a multifunctional motor test operation system and method, and the method comprises the steps: a parameter detection module synchronously collects voltage, current, frequency, temperature, vibration, insulation resistance and DC resistance parameters, and converts the parameters into electric signals; the data processing module carries out amplification, filtering and analog-to-digital conversion on the electric signal to obtain a measured value; the storage module stores the measured value; and the report generation module automatically generates a test run report containing parameter analysis and qualification conclusions through a preset template based on the stored value. The parameter detection module synchronously collects various parameters and converts the parameters into electric signals, the data processing module processes the signals to obtain accurate measured values, the storage module stores data, and the report generation module automatically generates a test run report containing analysis and conclusion based on the stored values. The problems that the function is single, data integration is difficult and report generation is tedious are solved, the testing efficiency and accuracy are remarkably improved, and manual errors are avoided.

The invention provides a positive electrode material, a positive electrode plate and a secondary battery, the positive electrode material comprises an element M, and the element M is selected from at least one of Na, K, Mg, Ca, Sr or Ba; the positive electrode material comprises a plurality of particles, the tangent plane of each particle comprises a central region and a surface region, the tangent plane of each particle is tested through an energy disperse spectroscopy, the average concentration of an element M in the central region is X1, the average concentration of the element M in the surface region is X2, and X1 and X2 meet the condition that X2 / X1 is larger than or equal to 1.2 and smaller than or equal to 20; the total mass content of the sulfur element in the positive electrode material is A1, the mass content of the sulfur element in the free sulfate radical in the positive electrode material is A2, and (A2 / A1)% is less than or equal to 70%. The positive electrode material provided by the invention is stable in structure and low in direct-current resistance, and is beneficial to improving the cycle performance and long-term electrochemical performance of the secondary battery.

The invention relates to the technical field of batteries, in particular to a surface modification method of a positive electrode. The surface modification method of the positive electrode provided by the invention comprises the following steps that an aluminum source, a carbon nano tube and the positive electrode are mixed and calcined, the surface-modified positive electrode is obtained, the addition amount of the aluminum source is 300 ppm to 900 ppm, and the addition amount of the carbon nano tube is 300 ppm to 900 ppm according to the mass of the positive electrode. The surface of the positive electrode material is modified by coating the positive electrode material with the carbon nanotubes and the aluminum source, on one hand, contact between the positive electrode material and an electrolyte can be isolated to a great extent, and the cycle performance of the material is improved, and on the other hand, the mixture formed by the carbon nanotubes and the aluminum source has good rapid ion and electron transmission performance, and has good electrochemical performance. The migration rate of lithium ions can be improved, the direct-current resistance of the positive electrode material can be reduced, and meanwhile, the increase of the direct-current resistance in the circulation process is inhibited.

The invention discloses a polarity conversion method of a vehicle-mounted extra-high voltage direct current withstand voltage test device. Initially measuring and collecting data through a preset low-voltage scheme, and predicting the voltage, current and leakage current of the equipment by using an LSTM model. And then, constructing a digital twinborn model, collecting data in real time in a high-voltage test stage, and importing the model to predict a power state so as to realize early warning analysis. Based on the early warning result, the test scheme is dynamically adjusted, the test scheme comprises voltage, time and a monitoring strategy, and finally an optimized target test scheme is generated, so that the accuracy and the safety of the power equipment test are improved.

The utility model belongs to the technical field of detection equipment, and discloses mining special cable bending test equipment, which comprises a workbench, a direct current resistance tester, a PLC (programmable logic controller) electrical control unit and a PC (personal computer) control unit are mounted on the workbench, a driving mechanism is mounted on the workbench, a driving belt wheel is mounted at the output end of the driving mechanism, and the driving belt wheel is driven by a motor. The driving belt wheel is in transmission connection with a driven belt wheel, a rotating shaft is installed at the axis of the driven belt wheel, and rotating teeth are installed on the rotating shaft; the workbench is provided with two fixed pulley assemblies and a movable pulley assembly, and the movable pulley assembly is located between the two fixed pulley assemblies. By the adoption of the structural design, the corresponding bending wheels can be selected according to different cable models, the bending strength and bending plastic deformation of the cable are larger, working condition simulation is closer, and relevant detection data can be obtained on line in real time.

The invention discloses a cable core through-flow efficiency detection method and device, and belongs to the technical field of distribution network cables, and the method comprises the steps: obtaining a to-be-detected cable sample; respectively measuring the sample total volume of the to-be-measured cable sample and the cable core volume of the to-be-measured cable core by using an equivalent volume replacement method; measuring the cable length and the adhesive tape volume of the cable core to be measured; calculating the cross-sectional area of the through-flow cable based on the sample total volume, the adhesive tape volume and the cable length; calculating a compression coefficient based on the cross-sectional area of the through-flow cable and the structural parameters of the cable core to be measured; calculating a conductive cross section ratio based on the sample total volume, the wire core volume and the adhesive tape volume; calculating a direct-current resistance coefficient based on the nominal sectional area of the cable core to be measured and the sectional area of the through-flow cable; and detecting the cable core through-flow efficiency of the to-be-detected cable sample according to the compression coefficient, the conductive cross section ratio and the direct-current resistance coefficient. Therefore, by implementing the method, the problem that the conductivity of the cable is difficult to accurately represent in the prior art can be solved.

The invention relates to an electrocoagulation guide wire and an electrocoagulation guide wire system. The electrocoagulation guide wire comprises a core wire body, a sheath and a coating, the core wire body is sleeved with the sheath, the coating is arranged on the sheath and part of the core wire body, the core wire body comprises a far-end section and a near-end section which are connected with each other from the far end to the near end, the far end of the far-end section is further provided with an electrocoagulation area, and the electrocoagulation area is arranged between the far-end section and the near-end section. The electrocoagulation guide wire is characterized in that the sheath and the coating are not arranged in the electrocoagulation area, under a 500V voltage test, the insulation resistance of the coating of the electrocoagulation guide wire or any point on the sheath which is not covered by the coating is not less than 10megohm, and the direct-current resistance of the electrocoagulation guide wire is less than 20ohm. According to the electrocoagulation guide wire, thrombus escape caused by thrombus formed by electrocoagulation outside aneurysm can be avoided, the risk of postoperative cerebral infarction is reduced, the operation safety is improved, and damage to materials of the electrocoagulation guide wire in the electrocoagulation process can be avoided.

To provide a negative electrode for a non-aqueous electrolyte storage element that can achieve both a low internal resistance (DC resistance) and a high capacity retention rate after charge / discharge cycles for the non-aqueous electrolyte storage element, and a non-aqueous electrolyte storage element that achieves both a low internal resistance (DC resistance) and a high capacity retention rate after charge / discharge cycles.SOLUTION: A negative electrode for a non-aqueous electrolyte storage element according to an embodiment of the present invention includes a negative electrode active material layer containing a carbon-based active material, a cellulose derivative, and a layered silicate, and the content of the cellulose derivative in the negative electrode active material layer is less than 0.8 mass%.SELECTED DRAWING: Figure 1

The invention relates to the technical field of battery management, and discloses a copper bar looseness identification method and device, equipment and a medium, and the method comprises the steps: obtaining multi-modal data of a battery system; the multi-modal data comprises at least one of voltage, current and temperature and equivalent direct current resistance; determining a first looseness prediction result of the battery system based on the change rates of the at least two types of multi-modal data; calculating the outlier degree of each copper bar point location indicated by the first looseness prediction result; and according to the outlier degree of each copper bar point location, generating positioning information and a fault result of the copper bar point location. According to the scheme, the limitation of single signal diagnosis in the prior art is broken through, and the copper bar looseness is analyzed by voltage-impedance combination based on multi-modal characteristics, so that the accuracy and robustness of copper bar looseness detection are improved.

A circuit for providing temperature compensation to sense signals in a single-ended DC resistance (DCR) sensing network for a multiphase switching power supply includes a temperature compensation calculator circuit generating a compensation adjust signal indicative of a sensed temperature; a compensating impedance network receiving the positive sense signals for all the phases and generating a correction signal for each phase in response to at least the positive sense signal for each phase and the compensation adjust signal; an average circuit coupled to average the correction signals of all phases, where copies of the average correction signal are applied to modify the positive sense signals; and an amplifier circuit receiving a summed positive sense signal being the sum of the modified positive sense signals for all the phases and a summed negative sense signal to generate an output signal having substantially zero temperature coefficient over the first frequency range.

The invention relates to the technical field of electric power, in particular to a cable nondestructive testing method which comprises the following steps: acquiring corresponding calibration parameters from a database according to the model of a to-be-tested cable, and calculating the total length and fault position of the to-be-tested cable at the near end of the to-be-tested cable by adopting a time domain reflection method; at the tail end of the cable to be detected, at the tail end, at least two core wires are short-circuited, a four-wire detection method is adopted to measure the direct-current resistance of a core wire loop at the near end, and standard temperature correction is conducted on the direct-current resistance of a single core wire; the resistivity to be measured is calculated by using the total length of the cable to be measured, the actual cross sectional area of the core wire and the direct current resistance of the single core wire at the standard temperature, and whether the actual core wire material of the cable to be measured is qualified is analyzed according to the resistivity to be measured and a resistivity threshold value set based on the calibrated core wire material. And early warning is carried out based on a core wire material analysis result and a fault position. According to the method, the cable length, the fault position and the core wire material qualification can be quickly, nondestructively and accurately detected on site.

The invention relates to the technical field of cable detection, and discloses a cable DC resistance detection and material identification method and system, and the method comprises the steps: constructing a four-wire system low-impedance electrical connection of a cable sample, compensating and correcting the path measurement precision through contact resistance, and obtaining an optimized electrical connection; monitoring a load state and performing closed-loop regulation on load impedance to obtain high-stability direct current; performing high-precision differential signal conditioning on the original voltage signal to obtain purified voltage data; deriving an initial resistance measurement value based on the purification voltage and the high-stability direct current, and performing system error compensation calibration on the initial resistance measurement value through a reference resistance comparison mechanism to obtain a calibrated direct current resistance value; obtaining material identification reference data according to a pre-stored mapping relation between the material and the resistance value in a material resistance database; the range attribution of the calibration direct-current resistance value in the material identification reference data is judged, and the material type is identified; according to the invention, the efficiency of cable DC resistance detection and material identification can be improved.

The invention discloses a computing power inductance device and a preparation method thereof. The computing power inductance device comprises a magnetic core, a conductor and a terminal electrode, the conductor is arranged in the magnetic core and led out of the magnetic core to form the terminal electrode, a soft magnetic composite material of the magnetic core comprises flat particles, and the flat particles are arranged in the soft magnetic composite material of the magnetic core. The ratio of the maximum width of the bottom / top surface of the flat particles to the thickness of the flat particles is 2.5-15. The computing force inductance device is higher in inductance value, higher in saturation current, higher in temperature rise current, lower in direct current resistance and more excellent in comprehensive electrical performance.

The invention provides an intelligent interface matrix for an integrated test of a power transformer, and aims to simplify complex wiring operation in a traditional test and improve the automation level and the working efficiency of test wiring of the power transformer. The intelligent interface matrix is composed of an intelligent control module, a test interface unit and a sensing monitoring module, and supports wiring tasks of conventional tests of dielectric loss, excitation characteristics, loop resistance, primary and secondary DC resistance of a current transformer, transformation ratio, dielectric loss, insulation resistance and the like of a voltage transformer. Signals such as voltage and current in a test are monitored in real time, the intelligent interface matrix automatically identifies the type of the power transformer, a test sequence is preset according to different types of transformers, a plurality of adjustable test interface units are stably and safely switched in a high-voltage and large-current environment, various test wiring work is efficiently and rapidly completed, and the test efficiency is improved. Manual intervention is remarkably reduced, and the test safety, reliability and overall working efficiency are effectively improved.

The invention discloses an on-load tap changing transformer direct current resistance measuring method and device, and the method comprises the steps: carrying out the sampling of the current of each phase winding of a transformer in the same gear state at a plurality of moments, obtaining the first sampling current data, and obtaining the time constant estimation value of each phase winding based on the first sampling current data; selecting sampling current values at a plurality of continuous sampling moments from the first sampling current data as second sampling current data, and obtaining a direct current resistance estimation value of each phase winding based on the current stability of the second sampling current data; and fitting the first sampling current data, and obtaining the optimal direct current resistance value of each phase of winding after optimization through iteration as the direct current resistance measurement value of the corresponding winding. The method can effectively avoid the defects of long measurement time, high measurement time point requirement and large measurement result error, improves the accuracy and reliability of direct current resistance measurement, is suitable for direct current resistance measurement of various transformers, and has a wide application scene.