233 results about "Inductive load" patented technology

The invention belongs to the technical field of unmanned aerial vehicle full-aviation electromagnetic detection, and particularly relates to a full-aviation frequency domain electromagnetic emission system and a control method. A broadband frequency mixing and matching circuit is connected in series between an H-bridge power inverter and an emission coil of an unmanned aerial vehicle electromagnetic emission system; the broadband mixing and matching circuit comprises a first resonance unit formed by connecting a fixed capacitor and an adjustable inductor in parallel and a second resonance unit formed by connecting a fixed capacitor and an adjustable inductor in parallel, and the first resonance unit and the second resonance unit are connected in series. The adjustable inductor is matched with the dynamic impedance of the inductive load by adjusting the inductance value, and the broadband frequency mixing and matching circuit can adjust the impedance in real time, so that the matching of different resonant frequencies is realized, and the frequency range of a matching signal can be obviously widened.

The invention discloses an audio and video data transmission anti-interference method and system based on coding error correction, relates to the technical field of audio and video data transmission, and is used for solving the problem that centralized error burst occurs in audio and video data transmission due to periodic strong electromagnetic interference generated by high-power inductive load equipment in an industrial production environment. The method comprises the following steps: acquiring predicted interference occurrence time, duration and reference intensity range of high-power inductive load equipment in an industrial production environment; detecting the channel quality of a transmission link to obtain the actual starting time and ending time of interference, the influence on a specific frequency range and the specific mode and length of error burst; predicting interference occurrence time according to an interference rule; generating a transmission strategy adjustment instruction according to the priorities of the multiple paths of audio and video streams; and according to the transmission strategy adjustment instruction, carrying out coding error correction or transmission time sequence adjustment on the multiple paths of audio and video streams before the interference occurrence time.

The invention discloses a current distortion suppression method and device for an N-phase AC-AC conversion system, and relates to the field of voltage conversion control, and the method comprises the steps: determining the ideal sine reference current of an xth phase, obtaining the actual input current of the xth phase in a current control period and the actual output current of the xth phase corresponding to an inductive load, and determining the current variation of the xth phase; and determining a difference value between the ideal sine reference current of the x-th phase and the actual input current as a real-time current distortion error signal of the x-th phase, further determining a compensation duty ratio of the x-th phase for suppressing current distortion by combining a preset duty ratio compensation strategy, and further determining a target duty ratio of the x-th phase as a target PWM signal. According to the scheme, the input current of each phase can be monitored, inductive load disturbance can be responded, the compensation duty ratio of the x-th phase used for restraining current distortion can be dynamically adjusted so as to determine the target duty ratio, the current distortion of the input current can be effectively restrained, and the input current can follow ideal sine reference current.

Techniques are provided for controlling alternating current (AC) power which is supplied to an inductive load by an AC switch. For example, the AC power is controlled by a process which comprises detecting zero-voltage crossings of an AC voltage waveform of the AC power, monitoring a load voltage to detect for a presence of inductive flyback voltage when the AC switch is placed into a turned-off state, and determining a delay time to place the AC switch into the turned-off state subsequent to a detected zero-voltage crossing of the AC voltage waveform, when inductive flyback voltage is detected in the load voltage, so that the AC switch is placed into the turned-off state at a time which substantially coincides with a zero-current crossing of load current of the inductive load, to thereby suppress the generation of inductive flyback voltage when the AC switch is placed into the turned-off state.

A load driver includes an active clamping circuit coupled between gate and source terminals of a power stage. The active clamping circuit serves to either pass through a gate drive voltage (provided by a gate driver) to the power stage in a PWM mode or to actively clamp the voltage between gate and source terminals of the power stage to enable fast decay recirculation in fast decay mode (when the load driver is configured for active clamping). A semi-active recirculation driver is coupled between ground and the output of the power stage. The semi-active recirculation driver serves to either provide a low impedance recirculation path in the PWM mode or to passively clamp the output voltage to provide for a fast decay recirculation path in fast decay mode (when the load driver is configured for passive clamping).

The invention discloses a method and system for testing electromagnetic radiation characteristics of an IGBT module for a converter valve, and the method comprises the steps: selecting an inductive load connection mode according to the position of an IGBT to be tested during testing: testing an upper IGBT, and connecting the two ends of an inductive load with a first wiring terminal and a second wiring terminal (the first wiring terminal is a neutral point between the upper IGBT and a lower IGBT) of the converter valve; and when the lower tube IGBT is tested, the first wiring terminal and the positive terminal of the bus capacitor are connected. A combined electromagnetic field probe is arranged around the IGBT to be detected, a probe shell is grounded, and a lead is connected with a signal conversion device. Firstly, a bus capacitor is charged to a stable voltage, and environmental background noise is collected by a probe when no gate pole is triggered. And pulse parameters are set by the upper computer and are sent to the driving board through the optical fiber to trigger the IGBT double-pulse action. Electric signals output by the probe are converted into optical signals through the photoelectric converter and transmitted to external equipment through the optical fiber to be restored. And subtracting background noise from a double-pulse measurement result, extracting a net radiation electromagnetic signal, and separating electromagnetic interference signals in different processes according to the switching time of the IGBT. The invention aims to accurately measure the radiation electromagnetic interference signal of the IGBT in the converter valve module in the switching-on, switching-off and diode follow current processes, and provides a basis for the electromagnetic compatibility design and shielding reinforcement of the converter valve module.

The invention relates to a cyclic aging test device for a power semiconductor device with a three-level three-phase bridge twin-dragging structure, which comprises a three-phase bridge test unit, a host control board and a slave control board, and is characterized in that the three-phase bridge test unit comprises a host three-phase bridge, a slave three-phase bridge and a three-phase inductive load with the same three-phase bridge structure; the three-phase bridge is connected with a power semiconductor device; the direct current ends of the host three-phase bridge and the slave three-phase bridge are connected in parallel, and the same group of direct current power supply Vdc supplies power to the host three-phase bridge and the slave three-phase bridge; the alternating current ends of the host three-phase bridge and the slave three-phase bridge are interconnected through the three-phase inductive load to form a twin-trawling structure; the slave control panel controls the voltage output of the three-phase bridge arm as the target of the current closed-loop control of the host control panel, and the host control panel simulates the actual working state of the power semiconductor device by adjusting a control strategy. The device has the beneficial effects that various real working conditions are simulated, and the cyclic aging test of the system-level AC type power semiconductor device is realized.

The invention discloses wafer dynamic parameter testing equipment which is provided with a testing device and a probe card for testing a wafer which is placed on a probe table and is internally provided with a to-be-tested device, and the probe card is provided with a plurality of probes connected with the to-be-tested device and a plurality of conductive contact pieces connected with the probes respectively. A connecting module of the testing device is provided with a plurality of connectors connected with conductive contact pieces, a high-voltage capacitor electrically connected with a high-voltage power supply in the testing device is connected with an inductive load module through a power switch, the inductive load module is connected with the connectors, and a control module is connected with a chip to be tested through the connectors. The control module realizes the dynamic parameter test of the device to be tested in the wafer by controlling the power switch to be turned on and turned off according to a certain time sequence, and the matching value of the probe card and the connector can reduce spurious oscillation signals so as to effectively improve the accuracy of the dynamic parameter test of the wafer. And therefore, the chip testing efficiency can be improved and the chip cost can be reduced.

The invention particularly relates to a three-frequency-band low-profile common-caliber antenna array based on a low-scattering wave-transparent structure, which comprises a low-frequency antenna and a group of 4 * 4-scale high-dual-frequency antenna arrays, the low-frequency antenna is positioned at the top of the array, and the high-dual-frequency antenna arrays are positioned at the bottom. The low-frequency antenna is composed of a low-scattering wave-transparent structure composed of two layers of electromagnetic surfaces, and the first electromagnetic surface located on the upper layer serves as a radiation structure of the low-frequency antenna and is directly excited by a feeder line to radiate electromagnetic waves to a free space. The second electromagnetic surface located on the lower layer and the first electromagnetic surface jointly form a low-scattering wave-transparent structure with frequency selection characteristics, and a multi-band broadband wave-transparent window with second-order response is achieved; the second electromagnetic surface is introduced to serve as inductive loading of the low-frequency antenna, the impedance matching condition of the low-frequency antenna is improved, and the low-profile design of the low-frequency antenna and even the whole array is achieved; and the low-frequency antenna has a wave-transparent characteristic for the high-dual-frequency antenna below the low-frequency antenna, so that the problem of directional diagram distortion caused by space shielding is avoided.

The utility model discloses a circuit capable of inhibiting surge voltage between contacts when a relay acts. The circuit comprises a relay, a resistor, a piezoresistor, a diode, a direct current electromagnetic coil and a binding post. When a high-capacity inductive load in a circuit loses power, a relatively high reverse electromotive force, namely a surge voltage, is generated. A resistor-diode series follow current loop and a piezoresistor-diode series surge suppression loop are reversely connected in parallel to the two ends of an inductive load, when the load loses power and generates reverse electromotive force, the follow current loop eliminates or reduces the electromotive force, and the surge suppression loop is conducted and shunted when the electromotive force exceeds a threshold value, so that surge voltage is prevented from being generated through dual protection; and a relay contact and a circuit are protected. The scheme is a passive suppression protection circuit, has the advantages of simple structure, low cost, fast response, recoverability, dual protection and the like, and improves the operation stability and reliability of equipment.

The invention provides a power distribution network partition optimization method and system. The method comprises the steps that a non-inductive load characteristic index set is constructed, non-inductive load characteristic indexes are constructed into characteristic vectors, electrical attributes of a power supply unit are constructed into attribute vectors, and then a two-dimensional evaluation model is constructed; obtaining a plurality of candidate partitions based on electrical attributes of the power supply units, calculating a comprehensive evaluation value of each load point and each power supply unit through a two-dimensional evaluation model, distributing each load point to the candidate partitions meeting a preset partition requirement through the comprehensive evaluation value, obtaining a preliminary partition scheme, constructing a global optimization model, and obtaining a final partition scheme; and optimizing each candidate partition to obtain a preliminary partition optimization scheme, constructing a corresponding power flow balance equation, and locally adjusting the preliminary partition optimization scheme to obtain a power distribution network partition optimization scheme so as to optimize the power distribution network partition. According to the invention, multi-dimensional evaluation is carried out on the power distribution network to optimize the reasonability of load division of the power distribution network, so that the operation reliability of the power grid is improved.

The application discloses an electromagnetic detection optimized bipolar SHMPWM transmitting method, which comprises the following steps: S1, by analyzing the influence of the resistive and inductive load on the transmitting current waveform distortion and the transmitting spectrum energy loss, extending the current waveform based on the equal-area principle, compensating for the lost transmitting current spectrum energy, and calculating the current waveform extension time; S2, considering the inductive load and the dead zone effect, establishing a bipolar SHMPWM nonlinear equation set; S3, using the particle swarm algorithm to iteratively operate the bipolar SHMPWM nonlinear equation set, and obtaining the solving result of the switching angle of the half-cycle symmetric SHMPWM. The application adopts the optimized particle swarm algorithm to solve the equation set to obtain the switching angle, and realizes that the frequency domain information of the half-cycle symmetric SHMPWM frequency focusing waveform conforms to the specific harmonic amplitude set by the expectation.

The invention provides an FRD chip detection method and platform. According to the method, a switch device and an inductive load module are controlled, a preset forward conduction working condition is established at an FRD chip, and when the FRD chip is in a forward conduction state, the switch device is controlled to switch the conduction state, so that reverse voltage is applied to the two ends of the FRD chip, and the reverse recovery process of the FRD chip is triggered. And then, synchronously acquiring the terminal voltage waveform of the FRD chip and the inductive current waveform associated with the inductive load module to obtain test data. Then, determining a reverse recovery characteristic parameter and an overvoltage characteristic parameter of the FRD chip under the inductive load working condition based on the test data, and finally, evaluating the FRD chip based on the reverse recovery characteristic parameter and the overvoltage characteristic parameter. Therefore, the technical problem that the dynamic performance of the FRD chip under the inductive load cannot be accurately evaluated under the traditional test condition is solved.

The invention discloses a continuous current pulse generation circuit for power device testing and a control method thereof, and relates to the technical field of power electronics, the continuous current pulse generation circuit comprises a power supply, a control unit, a switch unit, an energy storage unit, an inductive load and a current absorption unit; the switch unit comprises a first relay, a second relay, a third relay, n first switches and one second switch; the energy storage unit comprises n capacitors; the control unit is used for respectively controlling the on-off of the first relay, the second relay, the third relay, the n first switches and the n second switches, carrying out different-stage control on each capacitor, and providing continuous current pulse for the test of the power device; the different stages comprise a capacitor charging stage, a capacitor discharging stage according to a time sequence and a capacitor residual charge releasing stage. According to the invention, more real continuous current pulse can be provided for the power device, and the reliability test requirement of the device under the impact of the continuous current pulse is met.

The invention discloses a detection circuit and a detection method of an intelligent power module, the detection circuit comprises a power supply module, the intelligent power module, a microcontroller unit, an inductive load and a comparator, a first voltage dividing unit is electrically connected with the intelligent power module, a second voltage dividing unit is electrically connected with the microcontroller unit, and the microcontroller unit is electrically connected with the inductive load. The microcontroller unit is electrically connected with the intelligent power module; the microcontroller unit comprises an analog input port, an over-current signal port and a digital-to-analog converter port, the intelligent power module comprises a first alternating current output port, and the comparator comprises a positive input port, a negative input port and an output port; the analog input port is connected with the load resistor, and the first AC output port is connected with the sampling resistor; the positive input port is connected with the port of the digital-to-analog converter, the negative input port is connected with the first alternating current output port, and the output port of the comparator is connected with the overcurrent signal port. The structure of the invention can accurately determine whether the intelligent power module is over-current.

A driver circuit, including: a transistor including a ground side electrode, a control electrode, and a power supply side electrode for an inductive load to be connected thereto; a first resistor connected to the control electrode; a line connected to the first resistor; a second resistor provided between the line and a ground; a first diode, including a cathode connected to the line and an anode, the first diode being connected in parallel with the second resistor; and a second diode including a cathode connected to the line, and an anode for connecting to a capacitor, thereby receiving a voltage generated in the capacitor for driving the transistor.

The invention relates to the technical field of SiP power modules, and discloses a SiP power module integrated by SiCMOSFETs (silicon carbide metal oxide semiconductor field effect transistors) and diodes on a single chip for a medium-power and high-power energy storage power supply. Comprising a chip, the chip is composed of a single-chip integrated SiCMOSFET unit and a diode, the rear surface of the chip is provided with a module packaging plate, the front surface of the chip is provided with a substrate, the front surface of the substrate is connected with the SiCMOSFET unit and the diode, the rear surface of the substrate is provided with a first pin wire, the first pin wire is connected with the chip in a spot welding mode, and the first pin wire is connected with the chip in a spot welding mode. According to the invention, through the monolithic integration and optimized low-inductance packaging design of the SiCMOSFET and the diode and the combination of the advantages of the SiC material, the ultrahigh-frequency working capability, the extremely high conversion efficiency, the excellent thermal performance and the extremely high power density are realized at the same time, the system design is greatly simplified, the excellent reliability and the protection capability for inductive load switching are provided, and the application range is wide. Therefore, the power supply can be applied with high efficiency, high power density and high reliability, such as a medium-high power energy storage power supply.

This invention discloses a control circuit based on a hybrid switching timing of relays and thyristors. By connecting the thyristor in parallel with the relay, the thyristor bears the load current before and after the relay is closed, thus avoiding contact arcing. The control unit triggers the thyristor at the AC zero-crossing point, reducing switching losses and electromagnetic interference, and combines an RC snubber circuit with optocoupler isolation to improve reliability. This device can increase the relay lifespan from 20,000 cycles to 500,000 cycles, and its cost is only 1 / 3 that of a solid-state relay, making it particularly suitable for soft-start control of high-current inductive loads.

An integrated circuit (IC) includes an array of compute units and control circuitry for mitigating supply voltage overshoot. Each compute unit contributes to an aggregate time rate of change of current drawn by the IC when transitioning between processing and non-processing states. The control circuitry is configurable to stagger when each compute unit is eligible to transition from processing data to not processing data relative to other compute units, thereby limiting the negative rate of change of current through inductive loads of the IC and preventing voltage overshoot above a maximum threshold. The control circuitry may be distributed among the compute units and configured using statically reconfigurable parameters that specify the maximum number of compute units permitted to transition concurrently and the minimum number of clock cycles between successive group transitions.

An externally cooled high efficiency induction coil system is formed from a substantially planar electrically conductive strip, machined or 3D printed from solid copper or a copper alloy defining a multiturn solenoidal induction coil. Each turn of the multiturn induction coil is separated by a separation gap dimensioned to produce a low-variance heating pattern in a magnetically coupled inductive load or workpiece when an alternating current is supplied to the induction coil. A cooling fluid is forced over the induction coil and through the gap width to externally cool the induction coil via forced convection. The substantially planar electrically conductive strip may further include a plurality of crests and troughs defining a wave structure to increase surface area in contact with the cooling fluid and thereby increase efficiency in heat transfer.

A cascaded switched power converter provides a wide voltage conversion ratio and improved efficiency ins systems such as power supplies and amplifiers. A switched-capacitor charge pump circuit is operated by one or more first clock signals and is coupled in cascade with an inductor-based power supply circuit according to one or more second clock signals. A control circuit that generates clock signals so that the one or more second clock signals have a phase offset with respect to the one or more first clock signals that is set to adjust a conversion ratio of the cascaded combination of the switched-capacitor charge pump circuit and the inductor-based power supply circuit. The inductor of the inductor-based power supply circuit may be an inductive load, such as a speaker, and the phase offset may be modulated according to an audio signal to provide audio amplification.

The utility model discloses a low pressure series compensation device relates to the technical field of compensation circuit, including the soft start power supply circuit for controlling starting current slow rise, the surge impact is suppressed, the capacitive reactive power output for the dynamic regulation series capacitor, the low pressure reactive power compensation circuit of compensation inductive load's reactive power shortage, the voltage detection circuit for real -time tracking circuit voltage fluctuation, generates the voltage feedback signal required for compensation control. The utility model discloses through the voltage detection circuit, thereby through the accurate detection of resistance voltage dividing network and operational amplifier IC1, realizes real -time monitoring and signal conditioning to the grid voltage, ensures that compensation system can accurately obtain voltage variation information, provides reliable data support for reactive power compensation control.

This application belongs to the field of semiconductor technology and provides a gallium nitride-based HEMT device, a preparation method, and a chip. By integrating a Schottky diode into the gallium nitride-based HEMT device, the Schottky diode is composed of a channel layer, a barrier layer, a back capping layer, and a back gate layer. The back gate layer is disposed on the back surface of the back capping layer and is not in contact with the substrate layer that is also located on the back surface of the back capping layer. By dynamically controlling the voltage of the back gate layer, a lower forward conduction resistance and a higher device breakdown voltage are achieved, improving the performance of the device in the unclamped inductive load switching process test, and solving the technical problem in the related art that due to the lack of a corresponding parasitic diode in the GaN-based HEMT, the backflow current generated during the UIS test oscillates inside the device, causing devastating damage to the device.

The invention discloses a packaging structure and method for a multi-channel high-voltage large-current transistor module, and the structure comprises a housing, the upper end of the housing is provided with a housing sealing ring, the housing sealing ring is provided with a cover plate, the interior of the housing is provided with an inner surface electrode, and the exterior of the housing is provided with an external extraction electrode. Connecting points of the inner surface electrodes are connected with connecting points of the external extraction electrodes in a one-to-one correspondence mode, a plurality of driving control circuit chips, a plurality of power transistor chips and a plurality of driving inductive load protection circuit chips are arranged at the bottom of an inner cavity of the shell, and a plurality of bonding points are further arranged at the bottom of the inner cavity of the shell. The plurality of bonding points are used for realizing electric connection between the chips and the electrodes, and the plurality of driving control circuit chips, the plurality of power transistor chips, the plurality of driving inductive load protection circuit chips and the plurality of bonding points are distributed in an array; the power module has the characteristics of good electrical insulation performance, small size, light weight, high power density and high chip integration level.

DC-DC converter with an output-side storage capacitor arrangement for providing an operating voltage for an inductive load and for at least one further electronic circuit and / or electronic component of a vehicle electronics, wherein the storage capacitor arrangement is connected to the DC-DC converter via a reverse-biased diode (6) and the output-side storage capacitor arrangement is connected to a parallel circuit consisting of an electrolytic capacitor (1), a ceramic capacitor (2) and a circuit arrangement is formed with a series connection of a hybrid electrolytic capacitor (3) and a suppressor diode (4) and a resistor (5) connected in parallel to the hybrid electrolytic capacitor (3), wherein the hybrid electrolytic capacitor (3) has a lower series resistance than the electrolytic capacitor (1) and a larger capacitance than the ceramic capacitor (2), so that in the event of energy being fed back from the inductive load into the storage capacitor arrangement, the hybrid electrolytic capacitor (3) absorbs a large proportion of the energy and thus prevents a voltage increase at an output terminal above a value at which connected components can be destroyed, wherein the output terminal is the cathode terminal of the diode (6) and the inductive load can be connected to the output terminal.

The invention discloses an energy-consuming valve power module cyclic aging test platform and a cyclic aging test method, which are suitable for reliability verification of a direct-current energy-consuming device power module. Through collaborative design of a capacitive power supply and an inductive load, closed-loop utilization of energy is realized, and modularized alternating test logic is adopted, so that the test efficiency is improved. A direct-current power supply is used for providing a current source for a test loop, a test object is a test valve section formed by connecting a plurality of power module units in series, the test loop is composed of two test valve sections, and the two test valve sections are tested objects mutually. The design of the series energy consumption valve power module enables a plurality of tested modules to be subjected to cyclic aging at the same time. According to the invention, the power circulation of the energy consumption branch can be realized, and the data obtained through the test can be applied to key scenes such as health condition evaluation and control logic judgment of the IGCT device.

The invention provides a short circuit test circuit and a test device, and relates to the technical field of semiconductor testing, and the short circuit test circuit comprises a drive circuit, a test control circuit, a first load circuit, a second load circuit and a switching circuit. The first controlled end of the test control circuit and the first end of the first load circuit are both used for receiving test voltage. The first end of the switching circuit is connected with the second controlled end of the test control circuit, the second end of the switching circuit is connected with the second end of the first load circuit, the third end of the switching circuit is connected with the first end of the second load circuit, the second end of the second load circuit is grounded, and the second load circuit comprises an inductive load; a first output end of the driving circuit is connected with a control end of the test control circuit, a second output end of the driving circuit is used for connecting a control end of a to-be-tested device, a first end of the switching circuit is used for connecting a first controlled end of the to-be-tested device, and a second end of the second load circuit is used for connecting a second controlled end of the to-be-tested device.

The application discloses a load switching circuit, a load switching method and a household device, wherein a receiving module, a control module, a resistive load module and an inductive load module are included. The receiving module acquires an instruction signal; the receiving module sends the instruction signal to the control module; the control module determines a load module corresponding to the instruction signal according to the instruction signal, selectively controls the resistive load module or the inductive load module to work, receives a control signal transmitted by the control module through the receiving module, and transmits the control signal to the resistive load module and the inductive load module; according to specific instructions of the control signal, it is determined whether the resistive load module or the inductive load module works, different load type modules work according to user requirements, and the problem that different loads require different topological circuit requirements is overcome.

This invention discloses a circuit for suppressing back electromotive force (EMF) in a wire-feeding motor, comprising: a protection filter circuit, a half-bridge circuit, a half-bridge drive circuit, and an overvoltage monitoring and braking circuit. The protection filter circuit is connected to the power bus to prevent backflow of EMF into the power bus and to perform filtering. The half-bridge circuit is connected to the protection filter circuit and an external motor. The half-bridge drive circuit is connected to the half-bridge circuit to drive the half-bridge circuit and drive the motor to rotate. The overvoltage monitoring and braking circuit is connected to the protection filter circuit and the half-bridge drive circuit to monitor the voltage of the power bus. When the voltage of the power bus is too high, it performs rapid discharge and simultaneously drives the motor to stop rotating through the half-bridge drive circuit. This invention fundamentally cuts off the path of backflow of the back EMF generated by the motor or inductive load to the power supply by connecting a power diode D1 in series on the bus and utilizing its unidirectional conductivity.

The utility model belongs to the technical field of measurement, and particularly relates to experimental test equipment for measuring the current change rate, which comprises a base and a vertical plate, the vertical plate is fixedly arranged at the end part of the left side of the base, a capacitor is fixedly arranged on the inner side surface of the vertical plate, and the base and the vertical plate are of an integrated structure; a coil is rotationally fixed to the side, close to the vertical plate, of the top of the base, a wire groove is fixedly formed in the side, away from the vertical plate, of the top of the base, and the wire groove is in a 7 shape. According to the experimental test equipment for measuring the current change rate, based on the current change characteristics of an inductance element and a capacitance element, according to the Faraday's law of electromagnetic induction, when current changes in an inductive load, induced electromotive force is generated and counteracts current change, transient voltage fluctuation is caused, meanwhile, the capacitance element stores and releases energy, and the current change rate is measured. The current fluctuation is smoothed, and the transient change of the current is slowed down, so that reliable data support is provided for a power system, motor control and other electronic applications.