141 results about "Holding current" patented technology

The invention provides a control circuit of an excitation fuse, the excitation fuse and electronic equipment. The excitation fuse comprises N excitation sources, at least one melt and multiple sections of conductors, a melt is connected between every two sections of conductors in the plurality of sections of conductors; m excitation sources in the N excitation sources are connected to the multiple sections of conductors so as to collect currents of the multiple sections of conductors; the control circuit of the excitation fuse comprises a main control module and an inspection module. The inspection module is connected with the main control module; the main control module outputs an inspection signal to the inspection module so as to control the inspection module to detect the N excitation sources; if the holding current is detected from the N excitation sources, determining that the N excitation sources are in a normal standby state; and otherwise, determining that the N excitation sources have faults, and outputting prompt information to prompt a user to carry out fault removal. Therefore, the state of the excitation source in the excitation fuse can be detected, the fault of the excitation source can be found in time, and the reliability of the excitation fuse is improved.

The invention discloses a flexible interconnection and mode smooth switching method for a distributed power generation system, and relates to the technical field of distributed power generation, and the method comprises the steps: building a droop control relation through continuously collecting DC voltage and current for a source side rectifier of each power generation unit; in a normal mode, the output current of the back-to-back rectifier and the voltage of an intermediate capacitor are collected, the same phase of the current and the load current is kept by using phase locking control, and voltage regulation is realized by combining a dq coordinate model; when a fault of a source side rectifier is detected, an alternating current reference value is generated based on intermediate capacitor voltage deviation and is input into a single current loop controller for voltage stabilization, and meanwhile, a phase advance, adaptive gain and integral saturation resistance mechanism is introduced, so that quick response and stable operation are ensured; in the mode switching process, normal control quantity and fault control quantity are subjected to weighted fusion, and dynamic consistency is achieved through pole matching and reference pre-alignment; the intermediate capacitor voltage fluctuation is significantly reduced, the recovery time is shortened, and the system stability and reliability are improved.

A bidirectional PFC system includes a high-frequency branch with a first transistor connected between an IO node and a high-frequency tap, and a second transistor connected between the high-frequency tap and a reference node, and a low-frequency branch with a first thyristor connected between the IO node and a low-frequency tap, and a second thyristor connected between the low-frequency tap and the reference node. An inductor is connected between the first node and the high-frequency tap. A first capacitor is connected between the first node and the low-frequency tap. The first node and the low-frequency tap are coupled to input terminals. A control circuit generates first and second gate drive signals for the transistors so as to modify an AC signal at the input terminals such that the AC current falls below a holding current of the second thyristor prior to zero crossing of the AC voltage.

The invention provides an electrostatic powder coating airflow stability real-time compensation method, and relates to the technical field of powder coating control, the method is realized based on an electrostatic powder coating airflow stability real-time compensation device, the device comprises a master control MCU, a pneumatic control valve, a stepping motor driver for driving the pneumatic control valve, and a current sampling circuit coupled to the stepping motor driver, the current collector is used for collecting winding current of the stepping motor in real time. The method comprises the following steps that after a pneumatic control valve is opened to a target opening degree and enters a holding state, a static holding current value of the pneumatic control valve is obtained; comparing the static holding current value with a preset reference holding current value, wherein the preset reference holding current value corresponds to the holding current required by the target opening degree under the smooth state of the airflow channel; according to the offset of the static holding current value relative to the reference holding current value, whether the airflow channel has a blocking trend or not is judged; if not, the current target opening degree of the pneumatic control valve is maintained, the airflow state change can be more directly sensed, and real-time active compensation is carried out.

The invention discloses a magnetic field interference resisting module and method for a magnetic latching relay of an electric energy meter and a terminal. The anti-magnetic field interference module comprises an MCU, a relay drive circuit, a magnetic field intensity detection circuit and a relay anti-strong magnetic drive holding circuit. Whether the circuit is in a strong magnetic interference state or not is judged through a detection signal of the magnetic field intensity detection circuit, if strong magnetic interference exists, the driving current is increased through the relay anti-strong-magnetic driving holding circuit when the driving relay acts, and in a normal state, the driving current is increased through the relay anti-strong-magnetic driving holding circuit. And the strong-magnetic-resistance driving holding circuit of the relay is used for providing holding current for a relay coil, so that the permanent magnet magnetic flux density is increased, and the purpose of preventing misoperation of the relay is achieved.

The invention relates to a new energy grid-connected control technology, in particular to a grid-following type and grid-constructing type dual-mode switching control method and system for a voltage source converter, and the method comprises the steps: building an electrical topology and mathematical model of a grid-connected system, including modeling a main circuit under a synchronous dq coordinate system with a PCC voltage phase angle as a reference, obtaining active P and reactive Q expressions injected into the power grid; under the control of the following network type GFL, a PLL unit, a power outer ring and a current inner ring are adopted to realize synchronization and active / reactive injection control; under the control of the network construction type GFM, a power synchronous ring, an excitation ring, a voltage ring and a current ring are adopted to form network construction control; in the switching process, the current inner ring structure is kept consistent with the reference, when the GFM is switched to the GFL, the output of the power synchronous ring integrator serves as the initial value of the PLL unit integrator, and when the GFL is switched to the GFM, the output of the PLL unit integrator serves as the initial value of the power synchronous ring integrator.

The invention relates to the technical field of mechanical arm control, in particular to a mechanical arm speed control method based on load torque feedforward. The method comprises the following steps: acquiring an angular velocity and a three-phase current of a motor, and performing coordinate transformation to obtain a direct-axis current and a quadrature-axis current; generating a voltage control signal by using a current loop controller; generating a quadrature-axis current reference signal by using a speed ring controller; constructing a load torque observer based on the angular velocity and the quadrature-axis current to estimate the load torque in real time; an acceleration start flag and a deceleration start flag of the motor are detected, the estimated load torque is added to an input of the current loop controller as a feed-forward amount within a first predetermined time after the acceleration start flag is detected, and the feed-forward amount is removed from the input of the current loop controller within a second predetermined time after the deceleration start flag is detected. The constant parameters of the current loop and the speed loop controller are kept when the load and the rotational inertia change, and the stable suppression of the speed fluctuation is realized.

The invention provides a high-frequency high-low-voltage composite pulse plasma power supply device, which adopts a composite pulse control mode of high-voltage ignition and low-voltage holding current, and comprises a high-voltage direct-current circuit for providing voltage for enabling a plasma reactor to react; the first all-solid-state switch is used for outputting the high-voltage direct-current circuit in a pulse form to form high-voltage and high-frequency pulse electricity; the first one-way conduction circuit is used for conducting the high-voltage and high-frequency pulse electricity in a one-way mode and blocking current injection of the low-voltage side at the same time; the low-voltage direct-current circuit is used for providing voltage for maintaining arc in the plasma reactor for a period of time; the second all-solid-state switch is used for outputting the low-voltage direct-current circuit in a pulse form to form low-voltage high-frequency pulse electricity; the second one-way conduction circuit is used for conducting the low-voltage high-frequency pulse electricity in a one-way manner and blocking the current injection of the high-voltage side at the same time; and the plasma reactor is used for performing plasma reaction through high-voltage high-frequency pulse electric ignition and low-voltage high-frequency pulse electric maintenance arc state.

The invention discloses a method for starting a touch holding current of a hollow cathode by sparking a Hall thruster, and relates to the field of sparking of spaceflight electric thrusters. The problem that in the prior art, a technology for restraining the thruster from being extinguished due to ignition is lacked, so that the cathode needs to be heated and ignited again, and the thruster needs to be restarted is solved. The method is used for transferring pulse energy of abrupt change current generated during ignition between an anode of an anode power supply of the thruster and an anode of the thruster in a power supply system to a contact pole of the hollow cathode in a self-sustaining state of the hollow cathode of the thruster, so that extinguishing of the Hall thruster is inhibited. The method is mainly used for being applied to the hollow cathode self-sustaining state in the stable operation stage after successful ignition of the Hall thruster.

The invention discloses an insulated gate bipolar transistor device and a preparation process thereof, and the device comprises a substrate, a drain electrode which is formed below the substrate, a dielectric layer which is formed above the substrate, a source electrode which is formed above the dielectric layer, and a plurality of grooves which are formed in the substrate in a downward etching and sinking manner and are independently arranged, independent trench gates are deposited in the trenches, the cross section of the plurality of trenches is of a circular or annular or polygonal closed structure, and the trench gates are insulated and isolated from the side walls of the trenches and the source electrodes through dielectric layers. The novel groove type IGBT structure is achieved through the groove gates arranged in a circular layout mode, the structure has the advantages of being high in channel density, large in current density, simple in process and the like, and the chip area and the cost can be reduced while the current capacity is kept; or the current density and the power density of the device are improved while the chip area is maintained, and the on-state loss is reduced.

The utility model provides an intelligent control silicon controlled rectifier stable output circuit. The intelligent control silicon controlled rectifier stable output circuit comprises a silicon controlled rectifier signal input circuit, a rectification filter circuit, an intelligent control dimming module and a load power supply circuit. The rectification filter circuit is connected with the output end of the silicon controlled signal input circuit and is connected with the load power supply circuit through the active damping circuit. The intelligent control dimming module forms a control loop with a rectification filter circuit and a load power supply circuit through a plurality of electronic switch tubes, resistors, capacitors and other elements. When sine wave alternating current is input, the load power supply circuit outputs the maximum output current to the LED load; when a phase switching signal is input, the signal control end of the intelligent control dimming module outputs a high level, so that electronic switching tubes in the dummy load holding circuit and the small board load holding circuit are conducted and form a current loop, and therefore, a silicon controlled rectifier can obtain enough holding current and work stably; and the stability of the intelligent control silicon controlled rectifier stable output circuit is improved.

The invention provides a silicon carbide MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) integrated with an SCR (Selective Catalytic Reduction) and a manufacturing method thereof, and relates to the technical field of power semiconductor devices, the device is integrated with a PNPN four-layer structure consisting of a P + region, an N-type epitaxial layer, a P-type body region and an N + source region between a grid electrode and a source electrode, and the P + region is in metal ohmic contact with the source electrode. Through collaborative design of the distance and the doping concentration of the P + region and the N + source region, the forward and reverse trigger voltage thresholds of the PNPN structure can be accurately matched with the asymmetric driving window of the electric control main drive. The structure is arranged on the outer edge of a cellular area or a terminal area, and is electrically isolated from an active area, a field plate is arranged to suppress false triggering, ohmic contact is optimized to accelerate turn-off, and it is ensured that holding current is higher than parasitic latch triggering current, so that rapid and reliable discharge and self-protection of bidirectional surge between a gate and a source are achieved on the premise that the performance of a main device is not affected, and the reliability of the device is improved. And the gate oxide reliability is obviously improved.

The invention discloses an intelligent power consumption control method for a vacuum circuit breaker, and particularly relates to the technical field of circuit breakers. An electromagnetic response model of a permanent magnetic mechanism is constructed by obtaining environment parameters and historical operation data of a circuit breaker, and the relation between PWM frequency and a resonance area is judged in real time and dynamically adjusted; a test pulse mechanism is introduced to verify action conditions, and action accuracy is ensured in combination with closed-loop monitoring of current and magnetic field response; according to the method, the operation reliability, the action accuracy and the energy efficiency level of the circuit breaker in a complex environment are effectively improved.

A medical device configured to deliver a cardiac pacing pulse having a pacing pulse amplitude for delivery to an electrode terminal of the medical device is provided. In some examples, the medical device is configured to pull a latch current during a first portion of the cardiac pacing pulse by an internal adjustable load of the medical device coupled to a low side of a high side switch of a high voltage output circuit of the medical device to maintain the high side switch in an on state. The medical device may be configured to pull a holding current during a second portion of the cardiac pacing pulse to hold the high side switch in an on state. The holding current may be less than the latch current.

The application provides an electrostatic discharge protection device and a chip. The device comprises a substrate, a P-type region and an N-type region in the substrate, a first N-type doped region, a second N-type doped region, a first P-type doped region and a second P-type doped region in the P-type region, the second P-type doped region being between the first N-type doped region and the second N-type doped region, and the first N-type doped region being between the first P-type doped region and the second P-type doped region, a third N-type doped region and a third P-type doped region in the N-type region, and a gate above a region between the first N-type doped region and the second P-type doped region. The gate is connected with the second P-type doped region, the second N-type doped region is connected with the first P-type doped region as a negative electrode of the electrostatic discharge protection device, and the first N-type doped region, the third N-type doped region and the third P-type doped region are connected as a positive electrode of the electrostatic discharge protection device. The application can reduce the triggering voltage of the device and improve the holding current.

Embodiments of the present invention disclose a semiconductor discharge tube, a manufacturing method thereof, and an overvoltage protection device. Among them, the semiconductor discharge tube includes: a semiconductor substrate, a plurality of conductive blocks, and two electrodes. In any device unit region of the semiconductor substrate, the first conductive block is electrically connected to the first diffusion region and the fourth diffusion region; the second conductive block is electrically connected to the first diffusion region and the fifth diffusion region; on the shortest current flow path from the third diffusion region to the nearest first short-circuit point through the first diffusion region, it sequentially passes through that part of the first diffusion region in contact with the fourth diffusion region, the second short-circuit point, and that part of the first diffusion region in contact with the fifth diffusion region; the shortest distance from the end of the fourth diffusion region close to the third diffusion region to the second short-circuit point is greater than the shortest distance from the end of the fifth diffusion region close to the fourth diffusion region to the first short-circuit point. The technical solution provided by the embodiments of the present invention can achieve the characteristics of low turn-on current and high holding current.

The utility model discloses a wide voltage module for an accessory of an alternating current contactor, which comprises the accessory provided with a circuit board. The alternating current and direct current module is used for converting the input alternating current voltage or direct current voltage into correspondingly output direct current voltage; and the input end of the coil driving module is electrically connected with the output end of the alternating current and direct current module. A voltage sampling module outputs a high-level voltage signal or a low-level voltage signal according to an input voltage value, a control module makes a voltage signal for driving an alternating current contactor to be closed or released according to the high-level signal and the low-level signal, and after closing, the control module adjusts the duty ratio, so that a coil driving module only outputs a holding current of 10 mA to 13 mA; according to the scheme, the input AC / DC voltage range is 24V-480V, the size and the cost of the voltage conversion device are reduced, the adaptability of the power supply is improved, and the energy consumption is effectively reduced.

Amplifier (10) with high gain and high tracking speed, comprising: a pair of input transistors (MNP 12, MNN 14) to which input voltages (IN+ and IN-) are applied; a pair of loads switched as diodes (MPP 16, MPN 18) connected to the input transistors (MNP 12, MNN 14); at least a pair of current sources (MPIP 20, MPIN 22) connected to the loads switched as diodes (MPP 16, MPN 18);and a bias control (28) designed to switch off the at least one pair of current sources (MPIP 20, MPIN 22) to enable a high tracking speed for the amplifier (10), wherein the bias control (28) switches off the current sources (MPIP 20, MPIN 22) during a coarse tracking mode of the amplifier (10) when the amplifier (10) is tracking, and to switch on the at least one pair of current sources (MPIP 20, MPIN 22) to enable a high gain for the amplifier (10), and wherein the bias control (28) switches on at least one pair of current sources (MPIP 20, MPIN 22) at the end of the tracking and leaves the current sources (MPIP 20, MPIN 22) switched on when the amplifier (10) is not tracking.

The invention provides a power supply control structure with hot plug and current sharing functions and a control method, the power supply control structure comprises a switching power supply unit, a hot plug power supply module, a central controller and a plurality of electrical parameter acquisition modules, the switching power supply unit comprises a main power supply module and one or more slave power supply modules; the main power supply module and the slave power supply module are used for feeding electric power to a load in an independent or parallel control manner through the corresponding hot plug power supply module, the working mode of the power supply module is adjusted according to the magnitude of the input voltage, and a plug signal of the corresponding hot plug power supply module is started according to the magnitude of the output voltage of the main power supply module. And setting the power supply module to work in a main-standby mode or a current sharing mode according to the output power. According to the invention, rapid response and stability maintenance can be realized when the output voltage changes, and the current stability can be maintained when the load suddenly changes or the input fluctuates, so that the dynamic performance and the protection capability are improved.

The invention relates to an alternating current and direct current contactor control circuit and a contactor, and relates to the field of contactor control, and the alternating current and direct current contactor control circuit comprises an alternating current and direct current power supply module, a voltage detection module, an excitation control module, a closing maintenance module and a driving output module. The AC / DC power supply module is connected with an external driving power supply through an external driving power supply interface, and the voltage detection module is connected with the external driving power supply interface, the excitation control module and the closing maintenance module, so that different trigger signals can be formed to control the working states of the excitation control module and the closing maintenance module. The excitation control module is connected with the closing maintenance module and the driving output module, can control the driving output module to generate excitation driving current for driving the contactor to be closed, and can control the driving output module to generate closing maintenance current for maintaining the closing state of the contactor through the closing maintenance module, so that the real-time performance of contactor control can be improved; the operation power consumption of the contactor is reduced.

The invention relates to an LCC-MMC extra-high-voltage direct-current transmission line fault restarting method and an extra-high-voltage direct-current transmission system, and belongs to the technical field of extra-high-voltage direct-current transmission. When a line fault is detected, the LCC converter station controls the fault current to a direct current reference value; the MMC converter station controls the sub-module voltage to a rated value, the outer loop control output is switched to the sub-module voltage controller output, the direct current bias part of the direct current voltage reference value is switched to the direct current controller output, and the direct current reference value is the direct current reference value; after the deionization time is over, the DC bias part of the MMC converter station rises to a reference value, and the constant current control is quitted at the same time; when the current converter port voltage is detected to be greater than the starting value, the sub-module voltage control is quitted, and the outer loop control output is switched to the direct current voltage controller output; and the LCC converter keeps a current control mode, and when the DC voltage is detected to be greater than a completion value, the LCC converter station switches the current reference value to a real-time current reference value, and the line fault restart is completed.

A load control device for controlling the amount of power delivered from an AC power source to an electrical load is operable to conduct enough current through a thyristor of a connected dimmer switch to exceed rated latching and holding currents of the thyristor. The load control device comprises a controllable-load circuit operable to conduct a controllable-load current through the thyristor of the dimmer switch. The load control device disables the controllable-load circuit when the phase-control voltage received from the dimmer switch is a reverse phase-control waveform. When the phase-control voltage received from the dimmer switch is a forward phase-control waveform, the load control device is operable to decrease the magnitude of the controllable-load current so as to conduct only enough current as is required in order to exceed rated latching and holding currents of the thyristor.

The invention discloses a power regulation and control method and device of an energy storage battery and electronic equipment, and relates to the field of battery management. The method comprises the following steps: monitoring a first state parameter of a battery in real time, and constructing a multi-dimensional state space reflecting electrochemical activity attenuation and thermal runaway risk of the battery according to the first state parameter; wherein the state parameters comprise a thermal diffusion gradient, a polarization voltage abrupt change rate and a gas release rate; dynamically judging whether a power reduction mode is triggered or not according to the multi-dimensional state space; and when the power reduction mode is triggered, carrying out stepped power reduction operation on the battery until the output / input current of the battery is reduced to the load holding current. The technical problem that in the prior art, a single index is adopted for power management and control in battery management, charging and discharging may be stopped too early, and consequently part of actually available capacity cannot be utilized or battery life management is not facilitated is solved.

Valve control (3) for controlling a solenoid valve (2), comprising a control circuit (38) having an input interface (30) for receiving a switching signal and an output interface (31) for coupling a solenoid valve (2), and configured for processing the switching signal and for providing a coil current dependent on the switching signal to the output interface (31), wherein the control circuit (38) is configured to regulate the coil current to a pull-in current during a first time period and to regulate the coil current to a holding current that is less than 70 percent of the pull-in current during a subsequent second time period, wherein the control circuit is configured to increase the holding current by at least 20 percent for a limited time during the second time period if a predetermined coil current threshold is exceeded.wherein the control circuit (38) comprises a microcontroller which is configured to control the coil current during the first time interval and during the second time interval, characterized in that the control circuit (38) is configured such that the percentage increase of the holding current provided for when a predetermined coil current threshold is exceeded is determined by parameterizing the control circuit in order to enable the at least one solenoid valve (2) controlled by the valve control (3) to be adapted to different operating conditions.

The invention relates to a circuit for controlling a current through a relay coil, comprising an electronic switch for controlling the current through the relay coil and a comparator for controlling a control voltage applied to a control terminal of the electronic switch, a first voltage being applied to a first input terminal of the comparator, and a second voltage being applied to a second input terminal of the comparator. A second voltage is applied to the second input of the comparator, said second voltage being derived from the current through the relay coil, and the circuit is designed to reduce the current through the relay coil to a holding current after a switching process caused by a switching current through the relay coil.

To provide a seat belt retractor capable of suppressing power consumption in an electromagnetic lock type configuration.SOLUTION: The seat belt retractor 3 includes the electromagnetic vehicle sensor 40 having the electromagnet 50 and the actuator 60 and configured to switch between the locked state in which the locking mechanism 30 is operated and the unlocked state in which the locking mechanism 30 is not operated by operating the actuator 60 in response to energization of the electromagnet 50, the microswitch 90 as an example of the detection unit configured to detect the operation transition of the actuator 60, and the control unit 100 configured to control the current flowing through the electromagnet 50. A control part 100 switches a current flowing to the electromagnet 50 to a holding current C1 smaller than an operation current C1 when the operation transition of the actuators 60 is detected by the microswitch 90 after the operation current C2 for operating the actuators 60 is made to flow to the electromagnet 50.SELECTED DRAWING: Figure 9

The invention relates to the technical field of railway shunting control technology, and provides a turnout switching state sensing and interlocking control system for flat shunting, a data acquisition module of the turnout switching state sensing and interlocking control system is used for acquiring switch rail displacement voltage signals and switch machine motor current intensity, and calculating a switch rail displacement rate value through a displacement difference value and a time interval at adjacent moments; the conversion pre-judgment module judges a descending trend according to the switch rail displacement rate value and generates a low-frequency holding current instruction and a driving pulse cut-off instruction value; the mechanical verification module collects the displacement reading of the locking rod and the angle of the switch rail to obtain the integrity value of the mechanical structure; the interlocking logic module calls the driving pulse truncation instruction value and the structural integrity value to generate an interlocking state judgment value; and the signal control module outputs a high level to a shunting signal machine lighting circuit according to the interlocking state judgment value to generate a signal open level value. The problems that a mechanical locking structure mostly depends on manual or single-point verification, and linkage of interlocking logic and signal control is weak are solved.

The application provides a static powder coating airflow stability real-time compensation method, relates to the powder coating control technical field, and is realized based on a static powder coating airflow stability real-time compensation device. The device comprises a main control MCU, a gas control valve, a stepping motor driver for driving the gas control valve, a current sampling circuit coupled to the stepping motor driver and used for collecting the winding current of the stepping motor in real time. The method comprises the following steps: after the gas control valve is opened to the target opening degree and enters the holding state, the static holding current value is obtained; the static holding current value is compared with the preset reference holding current value, the preset reference holding current value corresponds to the holding current required by the target opening degree under the unobstructed state of the airflow channel; whether the airflow channel has the blocking trend is judged according to the offset of the static holding current value relative to the reference holding current value; if not, the current target opening degree of the gas control valve is maintained, the airflow state change can be directly sensed, and real-time active compensation can be performed.

The application provides a broken pile detection method and device, electronic equipment and a storage medium, and belongs to the technical field of engineering nondestructive testing. The method comprises the following steps: synchronously acquiring three types of data of holding current, grouting pressure and drill rod vibration at a first acquisition frequency, and calculating the holding current drop amplitude, the grouting pressure drop amplitude and the drill rod vibration frequency growth based on the three types of data. If the above indexes meet the over-limit early warning condition, the current drill rod drilling depth is acquired, and the second acquisition frequency is switched to to supplement the same type of data. The target parameter early warning threshold set is determined based on the soil property data corresponding to the current drilling depth. The three types of data acquired before and after the acquisition and the target parameter early warning threshold set are fused, and the broken pile risk probability is calculated. When the broken pile risk probability reaches the preset broken pile alarm probability threshold, the broken pile alarm information is generated. The application can realize timely identification and accurate early warning of the broken pile risk.

The application discloses a kind of test device and method with the key parameter of electrostatic protection mechanism with back sweep characteristic.The Pwell region, Nc gradually varying capacitance region, Nr resistance region, heavily doped N++, heavily doped N++, Psw region, upper electrode of inversion oxide layer and metal connection constitute the main body of the test device with the key parameter of electrostatic protection mechanism with back sweep characteristic.The application overcomes the defect that minimum back-through voltage and minimum holding current are not easy to measure directly, and can directly measure the minimum back-through voltage and minimum holding current of the electrostatic protection mechanism with back sweep characteristic;It is free from dependence on high-end power semiconductor scanner and TLP test system, and the test equipment used is common basic equipment rather than expensive and complex test equipment;During the test process, voltage and current change are relatively smooth, avoiding the influence of dv / dt, inductance impact, etc., and the measurement result is stable, and the measurement consistency is good.