98 results about "Phase inductance" patented technology

The invention discloses a position sensorless control method for a switched reluctance motor, and belongs to the technical field of motor control. According to the method, current chopping control is carried out in a conduction interval, low-threshold chopping control is carried out in a non-conduction interval, and the current hysteresis width changes along with the rotation speed, so that the rotor position estimation precision when the rotation speed is increased is ensured. According to the method, current information of each phase is collected, a current slope difference value is calculated, three-phase inductance is obtained through calculation according to the current slope difference value, the inductance obtained through calculation is compared with a preset inductance threshold value, and on-off signals of each phase and pulse signals of special position points can be obtained. According to the time interval between the rising edges of the adjacent position pulse signals and the corresponding rotor position angle difference value, the real-time rotating speed of the motor is obtained through calculation, and the motor rotor position at any moment is estimated. The method is simple in structure and convenient to implement, is not affected by inductance saturation, and is high in position estimation reliability and universality.

An automatic current sharing control method for an interleaved BUCK converter belongs to the technical field of power electronics, and comprises the following steps: step S1, obtaining an output voltage and a given output voltage of a load end of the interleaved BUCK converter; obtaining the current of each phase of inductor; s2, obtaining an average value of the inductive current of each phase, and averaging the average value of the inductive current of each phase as a reference value of a current loop; s3, calculating a duty ratio signal through a current loop; s4, calculating a duty ratio signal through a voltage loop; and S5, superposing the duty ratio signal of the current loop operation of each phase with the duty ratio signal of the voltage loop operation. According to the invention, the inductive current of each phase follows the average inductive current of three phases in real time, high-precision current-sharing control is realized, and the control reliability is improved, so that the output current is controlled at an average level.

The utility model relates to the technical field of inductors, in particular to a nickel-zinc four-phase inductor structure, which comprises an epoxy bottom plate, a nickel-zinc magnetic ring and four coil assemblies, the nickel-zinc magnetic ring and the four coil assemblies are arranged on the epoxy bottom plate, and the four coil assemblies are annularly arranged on the nickel-zinc magnetic ring at equal intervals. Each coil assembly comprises a coil body and two Teflon sleeves which are respectively sleeved at two ends of the coil body, the coil body is wound on the nickel-zinc magnetic ring, and two ends of the coil body are respectively arranged on the epoxy bottom plate in a penetrating manner. The four-way inductor is novel in structure, four-way output can be achieved at the same time, the size of the assembled inductor structure is small, and occupied space is reduced; under the action of the Teflon sleeve, the insulating property is improved; the magnetic ring made of the nickel-zinc material is beneficial to reducing energy loss under high frequency, so that the inductor generates less heat during working, and the overall efficiency is improved; the epoxy bottom plate can also assist in heat conduction and help the nickel-zinc magnetic ring to dissipate heat generated during working.

The invention discloses a heat balance phase management system of a multi-phase staggered Buck converter, and relates to the technical field of power electronics. The system comprises a working phase quantization module, a temperature monitoring module, a closed-loop control module and a fault early warning module, the number of effective working phases is dynamically adjusted through real-time monitoring of the inductive current of each phase and the temperature of a switching tube, a phase working enable signal is generated, and PWM signal modulation is achieved in cooperation with closed-loop control. The system can select a phase with lower temperature to be put into operation according to load current and temperature change, so that inter-phase heat balance is realized, the reliability of the system is improved, and the service life of devices is prolonged. Compared with an existing dynamic phase management technology, interphase heat distribution can be effectively optimized, aging of the switch tube is reduced, and system efficiency and long-term stability are improved.

The three-phase LC harmonic filter reactor comprises three magnetic core assemblies, the three magnetic core assemblies are annularly distributed, each magnetic core assembly comprises an upper cover magnetic core, a lower cover magnetic core and two center pillar magnetic cores, the top ends of the two center pillar magnetic cores are connected with the two ends of the upper cover magnetic core respectively, and the top ends of the two center pillar magnetic cores are connected with the two ends of the lower cover magnetic core respectively. The upper cover magnetic core and the lower cover magnetic core are arranged in the two magnetic core assemblies, the bottom ends of the two middle column magnetic cores are connected with the two ends of the lower cover magnetic core respectively, in the two magnetic core assemblies, every two adjacent middle column magnetic cores form a middle column magnetic core set, the middle column magnetic core sets are sleeved with coils, and the upper cover magnetic core, the lower cover magnetic core and the middle column magnetic cores are all metal magnetic powder cores. According to the structure, the precision of three paths of inductance values can reach the difference within 3%, meanwhile, each phase of inductance has only one coil, the processing difficulty that a traditional coil needs 8-shaped winding is avoided, the number of turns of the three-phase coils is completely the same, the process that a large amount of working hours are spent on adjusting the number of turns of the coils or padding air gaps to meet inductance balance in the production link is reduced, and the production efficiency is improved. Copper material consumption is saved, and production cost is reduced.

The utility model relates to motor driver test technical field discloses motor driver test load and motor driver testing arrangement, the motor driver test load includes: three -phase inductance load, three -phase inductance load includes a plurality of three -phase test end, wherein, the load between each three -phase test end is different, the motor driver to be tested is connected with target three -phase test end of three -phase inductance load, carries out the test based on target three -phase test end corresponding load, temperature sensor sets up in three -phase inductance load, gathers three -phase inductance load's temperature signal and exports, control unit is connected with temperature sensor, receives temperature signal, and when temperature signal is higher than temperature threshold value, exports cooling signal, cooling unit sets up in three -phase inductance load, cooling unit is connected with control unit, receives cooling signal and starts and reduces three -phase inductance load's temperature. The utility model solves the problem that the existing test motor driver's load commonality is low.

The invention relates to a method, a device and equipment for determining the operation condition of a switched reluctance motor. The method includes obtaining a first data set of phase inductance, phase current, and rotor angle for the switched reluctance motor. The method further includes expanding the first data set into a second data set by the neural network model, the phase inductance in the second data set being associated with the flux linkage of the switched reluctance motor, the flux linkage being used to determine the operating condition of the switched reluctance motor. Through the mode, the data sets of the phase inductance, the phase current and the rotor angle can be expanded based on the neural network model, the situation that only the switched reluctance motor is observed to collect data is avoided, the data size of the data sets is increased, the collection cost of the data sets is reduced, and therefore the accuracy of the flux linkage and the operation condition is improved; and thus, the control accuracy of the switched reluctance motor is improved.

The utility model provides a single-phase inductor insulation resistance test fixture, the whole test fixture is of a hollow cuboid structure, and a single-phase inductor is placed in the test fixture; the single-phase inductor comprises two terminal endpoints and a middle magnet, probes are arranged at the positions, corresponding to the two terminal endpoints, of the top and the bottom of one side face of the testing jig, conducting layers making contact with the magnet are arranged on the inner walls of the two side faces of the testing jig, the conducting layers on one sides of the terminal endpoints transversely penetrate through the side faces, and the conducting layers on the other sides of the terminal endpoints transversely penetrate through the middle magnet. The other side surface is fully covered with a conductive layer; connecting wires are led out of the probe and the conductive layer and are inserted into insulation resistance testing equipment. According to the utility model, through the structural design of the test tool, especially the arrangement of the conductive layer, the insulation resistance of the inductor can be tested at one time, so that the test efficiency can be improved, the test accuracy can be improved, and the risk that defective products flow out is greatly reduced; the jig is simple in structure, convenient to use and wide in application range, and the test difficulty can be reduced.

The invention relates to the technical field of buck-boost converters, and discloses a phase control circuit and method, and a buck-boost system. According to the phase control circuit provided by the embodiment of the invention, the edge change rate of the phase-cut inductive current is slowed down by processing the phase-cut signal, so that when the double-phase reverse buck-boost converter performs phase cutting based on the phase-cut signal, one single-phase buck-boost converter can enter or exit softly, and the other single-phase buck-boost converter can enter or exit softly. Therefore, the ripple of the load voltage signal at the output end of the dual-phase reverse buck-boost converter is ensured to meet the design requirement, and the load connected with the dual-phase reverse buck-boost converter is prevented from working abnormally.

This invention belongs to the field of power electronics and electric vehicle charging technology, and discloses a bidirectional electric vehicle charger topology, control method, and system, including a grid-side module, an AC-DC module, and a DC-DC converter. The grid-side module includes a three-phase power supply from the grid, a first-phase resistor Rga, a second-phase resistor Rgb, and a third-phase resistor Rgc. The AC-DC module includes a power switching transistor group, a first capacitor C1, and a second capacitor C2. The three-phase output terminals of the grid power supply are respectively connected to the first-phase inductor Lga, the second-phase inductor Lgb, and the third-phase inductor Lgc. This invention eliminates the need for additional filtering hardware, reducing manufacturing costs, physical size, and system complexity, while improving power density and reliability. It can accurately locate and specifically compensate for critical harmonics of specific orders in the power grid, and can quickly and in real-time track and suppress dynamically changing harmonics and transient disturbances.

The application discloses a kind of three-phase rectifier multiple switch tube open-circuit fault diagnosis methods based on voltage deviation, belong to power electronic converter fault diagnosis technical field.Method includes: obtaining relevant signal for diagnosis;According to three-phase voltage, three-phase current, three-phase inductance value, three-phase equivalent resistance value and switching period, the actual value of three-phase line voltage is calculated;According to DC voltage and the duty cycle of switch tube on three-phase bridge arm, the expected value of three-phase line voltage is calculated;Difference is obtained between the expected value and actual value of three-phase line voltage;The deviation value of three-phase line voltage is compared with first preset threshold and second preset threshold, to determine the polarity of the deviation value of three-phase line voltage;Wherein, first preset threshold is less than second preset threshold;The polarity of the deviation value of three-phase line voltage is combined with voltage phase, to determine fault switch tube.The application can quickly diagnose for various situations of multiple switch tube fault, including single switch fault, two switch tubes in succession fault, two switch tubes simultaneous fault.

A inverter device for a vehicle has a three-phase inverter, a filter device, a first supply voltage terminal feeding DC voltage from a vehicle battery, a second supply voltage terminal connecting to the vehicle battery, a first supply terminal supplying first AC voltage, a second supply terminal supplying second AC voltage, and a third supply terminal supplying third AC voltage. The filter device has a first coupling terminal electrically coupling with the first supply terminal and a second coupling terminal electrically coupling with the second supply terminal, a filter output supplying filtered AC voltage, and a neutral conductor output. The filter device has a first phase inductance connected between the first coupling terminal and the filter output, a second phase inductance connected between the second coupling terminal and the neutral conductor output, and a filter capacitance connected between the filter output and the neutral conductor output.

A flat multi-phase inductor is provided. The flat multi-phase inductor includes a main iron core, a plurality of first coils, a plurality of second coils and a plurality of secondary iron core. The main iron core has a plurality of accommodating spaces, the plurality of first coils are respectively disposed in the plurality of accommodating spaces. The plurality of second coils are respectively disposed in the spaces defined by the plurality of first coils, and the plurality of secondary iron core are respectively disposed in the spaces defined by the plurality of second coils. The second coil includes a series part, and the series part connects two adjacent second coils to each other in a regular manner. The secondary iron core, the second coil and the first coil are correspondingly disposed in a plurality of accommodating spaces of the main iron core to form an inductor element.

The application provides a vertical-axis phase-synchronous pulse injection control method for a hybrid excitation variable reluctance motor, and belongs to the technical field of motor control. The method comprises the following steps: S1, configuring a hybrid excitation variable reluctance motor, which comprises two sub-phase components, and each sub-phase component is powered by a three-phase four-bridge-arm inverter; S2, constructing a self-induction model under pulse detection signal excitation based on the structure of the hybrid excitation variable reluctance motor; S3, sequentially injecting detection pulse voltages into each phase by adopting the vertical-axis phase-synchronous pulse injection method, obtaining the size of the inductance value of each phase, thereby judging the current sector where the rotor is located, and substituting the bias electric angle into the self-induction model to calculate the bias electric angle; and S4, calculating the electric angle of the rotor magnetic field at the current moment according to the bias electric angle.

The present invention discloses an overcurrent protection method and system for a vehicle-mounted inverter, relating to the field of inverter technology. The method comprises: step 1: within a single pulse width modulation cycle, performing multiple rapid sampling of the output current of the shunt resistor of the vehicle-mounted inverter to obtain a phase current estimate that is closer to the true instantaneous phase current; step 2: constructing a transient overcurrent risk index based on the phase current estimate, combined with the motor phase inductance, DC bus voltage, and the motor's electrical time constant; step 3: using the nominal rated current as a reference, adaptively adjusting the trip threshold according to the transient overcurrent risk index; and step 4: activating soft shutdown logic to perform overcurrent protection on the vehicle-mounted inverter based on the transient overcurrent risk index and the phase current estimate. The present invention significantly improves the accuracy and sensitivity of overcurrent protection, achieving intelligent quantitative risk assessment and dynamic adaptation of protection boundaries.

The invention discloses a pre-synchronization grid-connection method for a grid-construction type converter under an unbalanced power grid, and the method comprises the steps: 1, obtaining the positive-sequence components and negative-sequence components of three-phase grid-connection point voltage, three-phase output current, three-phase output voltage and three-phase inductive current; step 2, determining the positive sequence amplitude and the negative sequence amplitude of the grid-connected point voltage; step 3, generating a negative sequence voltage given value of the network construction type converter; step 4, determining a positive sequence voltage given value, a positive sequence voltage frequency value and a positive sequence voltage phase value of the network construction type converter; 5, performing double-loop control of positive sequence voltage and positive sequence current and double-loop control of negative sequence voltage and negative sequence current on the voltage output by the grid-forming converter and the positive sequence component of the inductive current; and step 6, judging whether a grid connection condition is met, and if yes, ending pre-synchronization. The problem of failure of pre-synchronization grid connection of the grid-forming converter under the three-phase unbalanced power grid is solved.

The invention relates to stall detection of a BL DC motor comprising one or more motor phases for each motor phase a phase inductance L, and a phase resistance R. A driver (213, 230) is configured for driving (110) the BLDC motor (220) by applying a voltage or a current vector to one or more motor phases of the BLDC motor (220) with a rotation speed ω of the voltage vector or the current vector; a detector (212) is configured for obtaining (120) an electric angle between the applied voltage vector and a resulting current vector or between the applied current vector and a resulting voltage vector; a processing device (211) is configured for determining a stall of the rotor if the absolute value of the electric angle or a filtered version thereof crosses a stall threshold value wherein the stall threshold value is arctan2(ωL, R) plus or minus a predefined margin.

The invention discloses a loss optimization method and system for an integrated three-phase transformer, and the method comprises the steps: building a transformer equivalent magnetic circuit model according to a magnetic core structure of the integrated three-phase transformer, and obtaining an equivalent magnetic circuit diagram; calculating the magnetic flux value of each part of the transformer magnetic core according to the equivalent magnetic circuit diagram; according to the magnetic flux value of each part, calculating to obtain a balanced three-phase inductance value; according to the three-phase inductance value and the magnetic flux distribution, a total magnetic core loss value is obtained through calculation by adopting a segmented integration mode through a Steinmez formula; under the given working condition and device parameters, the size of each part of the magnetic core is selected as an optimization variable, the three-phase inductance and magnetic flux balance and the side column and cover plate magnetic flux consistency serve as optimization constraints, optimization calculation is conducted according to the total magnetic core loss value, and the optimal magnetic core size parameter is obtained. According to the invention, the problems of non-uniform magnetic circuit distribution and asymmetric transformer parameters caused by unmatched magnetic core sizes can be solved, so that the performance and efficiency of the transformer are improved.

The invention relates to stall detection of an electronically commutated electric machine comprising one or more machine phases, with a phase inductance L and a phase resistance R for each machine phase. The driver (213, 230) is configured for driving (110) the electronically commutated electric machine (220) by applying a voltage or current vector to one or more motor phases of the electronically commutated electric machine (220) at a rotational speed omega of the voltage or current vector; the detector (212) is configured to obtain (120) an electrical angle between the applied voltage vector and the resulting current vector, or between the applied current vector and the resulting voltage vector; the processing device (211) is configured for determining a stall of the rotor if the absolute value of the electrical angle or a filtered version thereof crosses a stall threshold, where the stall threshold is arctan2 ([omega] L, R) plus or minus a predefined margin.

The application discloses a four-phase different-name end coupling magnetic integrated inductor, which comprises an upper cover plate, a lower cover plate, four magnetic columns and four windings; the upper cover plate and the lower cover plate are of the same shape, and the four magnetic columns are of the same shape; the four magnetic columns are uniformly distributed in a horizontal direction around a vertical connecting line of a center point of the upper cover plate and a center point of the lower cover plate; the upper cover plate covers upper surfaces of the four magnetic columns, and the lower cover plate covers lower surfaces of the four magnetic columns; the four-phase different-name end coupling magnetic integrated inductor further comprises a partition air gap; the four windings are of the same structure and are wound on the four magnetic columns respectively to form four-phase inductors which are magnetically coupled; after current excitation is applied to the four windings, magnetic fluxes generated in the four magnetic columns are of the same direction. The four-phase winding different-name end coupling makes the magnetic fluxes generated in the upper cover plate of the magnetic core and the lower cover plate of the magnetic core have the same direction, so that the four-phase inductors can be reduced to a certain extent. The four-phase different-name end coupling magnetic integrated inductor is favorable for reducing inductance current ripple and in turn reducing winding loss, and can improve current uniformity and rated value of the four-phase inductors.

The invention discloses a three-phase switched reluctance motor torque control method based on alignment position detection, and relates to the technical field of motor control. Injecting a high-frequency current pulse into a non-conducting phase of which the inductance is monotonically changed along with the position in each position sector taking two adjacent aligned positions as end points, and ensuring that the non-conducting phase has no tail current before injection; estimating the inductance of the non-conducting phase according to the rising slope of the high-frequency current pulse injected into the non-conducting phase or the falling slope of the trailing current; if the inductance is smaller than the preset threshold value, instantaneous torque control based on a torque distribution function is adopted according to the inductance estimation position; otherwise, not estimating the position, neglecting the change of the conduction phase torque along with the position, and determining the conduction phase given current according to the current-torque characteristic at the 60-degree electrical angle position. As only the alignment position needs to be detected and the instantaneous torque control area is expanded, compared with the technology that instantaneous torque control is adopted only in the two-phase conduction area, the cost of the position sensor can be reduced, and torque pulsation can be restrained.

The invention discloses a switched reluctance motor sliding mode control-torque distribution function control system and method, and relates to the field of switched reluctance motor control. The change of the change rate of phase current is caused along with the change of phase inductance when the switched reluctance motor runs, and the change of the torque tracking capability of the previous phase and the next phase is caused, so that the torque compensation is carried out according to the change of the torque tracking capability of the previous phase and the next phase, the traditional sine type torque distribution function is improved, and the torque pulsation of the motor is reduced. According to the method, an off-line optimization control strategy and an on-line optimization control strategy are also provided to optimize the opening angle, so that the phase current peak value is reduced while the torque ripple of the motor is suppressed.

This utility model discloses a three-phase inductor, including a three-phase magnetic core structure, corresponding winding structures, and lower and upper mounting brackets respectively disposed at the upper and lower ends of the three-phase magnetic core structure. The lower mounting bracket is provided with a first positioning component that positions and cooperates with the bottom of each phase magnetic core, which is composed of multiple lower positioning plates arranged circumferentially around the bottom of the magnetic core. The upper mounting bracket is provided with a second positioning component that positions and cooperates with the top of each phase magnetic core, the second positioning component including an upper positioning cover that covers the top of the magnetic core. By connecting the upper and lower mounting brackets through multiple sets of locking components and applying opposing overall clamping forces, the magnetic core is rigidly fixed. The three-phase inductor with this structure design effectively ensures the coaxiality of the three-phase magnetic core by synchronously constraining the radial movement and axial displacement of the magnetic core structure through bidirectional positioning, ensuring the stable electrical performance of the inductor, improving production and assembly efficiency, and saving installation space.

The invention discloses an optimal control method and system for a bipolar AC-AC converter under three-phase inductance asymmetry. The bipolar AC-AC converter is of an ABC three-phase structure, each phase comprises an upper bridge arm and a lower bridge arm which are the same, each of the upper bridge arm and the lower bridge arm comprises n full-bridge sub-modules and a bridge arm inductor which are connected in series, and the three-phase bridge arm inductors are different. The control method provided by the invention comprises three parts: firstly, suppressing power frequency negative-sequence current to be 0 in a dq coordinate system on a power frequency side, secondly, suppressing low-frequency negative-sequence current to be 0 in the dq coordinate system on a low-frequency side, and thirdly, eliminating three-phase capacitor voltage difference to be 0 in an alpha-beta coordinate system. Through negative sequence control and capacitor voltage balance control strategies, optimal control of the bipolar AC-AC converter under the condition of asymmetric three-phase inductance parameters is realized, suppression of negative sequence current and balance of capacitor voltage are realized, the running consistency of three-phase bridge arms is effectively maintained, and the reliability of the three-phase bridge arms is improved. And the safe operation capability of the bipolar AC-AC converter is improved.

The present invention discloses a two-phase interleaved flying capacitor bidirectional DC converter based on coupled inductors, which relates to the field of power electronics technology. The DC converter is two-phase interleaved and parallel-connected, and the inductors between the two phases are magnetically coupled. It includes four groups of bridge arms, four flying capacitors, a pair of coupled inductors, and two filter capacitors. Among them, the coupled inductors are reversely coupled. Each group of bridge arms is composed of four power switches connected in series, with a total of sixteen power switches. The characteristics of the present invention are that it can perform bidirectional step-up and step-down. The voltage stress of each power switch is half of the voltage bus. Interleaved parallel connection can reduce the ripple of the output current while increasing the conversion efficiency of the converter. The magnetic integration technology further reduces the inductance and the volume of the converter, reduces the phase current ripple of each phase inductor, and improves the dynamic performance of the converter at the same time. It has good application and development prospects for the energy storage link of new energy distributed power generation systems such as light and wind.

The invention belongs to the technical field of inductance equipment manufacturing, and particularly relates to a three-phase inductance coil winding device and method. Comprising a base, and a driving roller and two driven rollers are mounted at the top of the base; a magnetic ring is connected between the driving roller and the two driven rollers in an abutting mode. A first electric telescopic rod is further installed at the top of the base and located below the magnetic ring, and a wire hook is fixedly arranged at the end of the first electric telescopic rod. According to the invention, the problems of complex process and low efficiency caused by repeated winding and repeated cutting during preparation of the three-phase inductance coil can be avoided through one-time forming, and meanwhile, the magnetic ring is not damaged; the device can quickly adapt to the size change of the magnetic ring and the operation of the rollers, the problem that the magnetic ring cannot rotate due to inaccurate adjustment caused by respective adjustment of the rollers is solved, the device can be quickly reset, and the fine adjustment efficiency is greatly improved; the multi-coil winding and cutting device is suitable for large-current multi-coil winding and cutting at the same time.

The invention provides a power supply system and a power supply method. In one embodiment, the power supply system includes a first rectifier filter, a second rectifier filter, and a power management module. The first rectifier filter is connected to a first winding and is used for providing an output power supply. The second rectifier filter is connected to an auxiliary winding for providing an auxiliary power supply. The auxiliary winding is inductively coupled with the first winding. The number of turns of the first winding is greater than the number of turns of the auxiliary winding. The power management module is connected to the auxiliary power supply and the output power supply, and selects or does not select the output power supply as an input power supply according to one of an operation power supply and the output power supply. The input power supply is used for enabling the power management module to generate and regulate the operation power supply.

The application discloses a kind of non-fault phase continuous power supply three-phase inverter short-circuit current limiting method and system, belong to independent power supply system protection control field.The system described in the application includes normal control system and fault control system, normal control system includes capacitor voltage outer ring, fault control system includes non-fault phase capacitor voltage outer ring and adaptive phase angle adjusting link based on SOGI filter, both are connected with inductance current inner ring by switching module.The application has the advantages of fast current limiting response speed, simple control structure compared with existing strategy.When asymmetric fault occurs, the output current of fault phase can be maximized and the reliable power supply of non-fault load of the system can be ensured.The application can adaptively change the phase angle between fault and non-fault inductance current, which can make the inverter always meet the system power supply and current limiting requirements with good robustness.

The present invention discloses a method for obtaining d-q-0 axis inductance parameters of an open-winding permanent magnet synchronous motor, comprising the following steps: S101, short-circuiting U, V, and W terminals of the open-winding permanent magnet synchronous motor; S102, passing low-voltage direct current between phases A and B of the motor to lock the angle between the rotor reference axis and the stator A-phase axis. After the angle between the rotor reference axis and the stator A-phase axis is locked, cutting off the power supply; S103, measuring the phase inductance of the stator three-phase winding; S104, measuring the line inductance of the stator three-phase winding; S105, calculating the mutual inductance between the three-phase stator winding; S106, obtaining a relationship between the three-phase winding flux linkage and the d-q-0 axis inductance based on a mathematical model of the open-winding permanent magnet synchronous motor; and S107, applying coordinate transformation theory to derive an expression for the d-q-0 axis inductance represented by the phase inductance and the line inductance, and substituting the expression into the measured data to obtain the d-q-0 axis inductance.

The invention discloses a low-ripple hydrogen production power supply based on a pseudo-continuous multi-phase interleaving parallel converter, which relates to the technical field of water electrolysis hydrogen production and comprises a direct-current power supply, an electrolytic bath, a three-phase interleaving parallel Buck power unit and three pseudo-continuous follow current branches, the three pseudo continuous follow current branches are respectively connected between three-phase switch nodes and output ends of the three-phase staggered parallel Buck power unit, and the pseudo continuous follow current branches adopt follow current switch devices and are used for conducting and connecting the switch nodes and the output ends in a follow current stage, so that voltages at two ends of a phase inductor are approximately zero; and the input end and the output end of the three-phase interleaving Buck power unit are respectively connected with a direct-current power supply and an electrolytic bath. Wide-working-condition low-ripple output can be achieved under the condition that the size of the output filter is not remarkably increased, the operation efficiency of the electrolytic cell is improved, the service life of the electrolytic cell is prolonged, and the requirements of a large-scale hydrogen production system for a high-reliability and high-efficiency power source are met.