1568 results about "Voltage range" patented technology

The invention relates to a PFC-PWM (Pulse Width Modulation) dual-mode control method for a high-voltage direct-current power supply with a wide output voltage range. The output current of the high-voltage direct-current power supply is detected in real time, the critical threshold value of the load impedance is mapped into the hysteresis interval of the output current, the theoretical boundary of mode switching is obtained, and the control mode is dynamically adjusted. In order to further guarantee smooth switching of the two control modes, hysteresis control logic is designed, and undisturbed smooth switching of the PFM mode and the PWM mode is achieved. Based on an energy equivalence principle and a frequency consistency constraint of a critical load SWL working point, a current threshold criterion and a parameter pre-synchronization strategy are constructed, seamless connection of a mode switching process in a frequency domain and an energy domain is ensured, a transient oscillation risk is remarkably reduced, and a guarantee is provided for continuous and stable output of a full-range load working condition.

A circuit arrangement (10) for controlling an output voltage of the circuit arrangement (10). The circuit arrangement (10) comprises battery cells (121) forming a plurality of series-connectable cell modules (120, 120′). The cell modules (120, 120′) comprise: a first group of cell modules (150) comprising a first number of cell modules (150), Each cell module (120, 120′) of the first group has a first nominal cell module voltage in a range of 30-200 V, and at least one second group of cell modules (150′) comprising a second number of cell modules (150′). Each cell module (120, 120′) of said at least one second group has a second nominal cell module voltage that is less than the first nominal cell module voltage. The circuit arrangement (10) comprises a control unit (20) configured to: measure the output voltage of the circuit arrangement (10), and in order to control the measured output voltage towards the voltage target, control at least one respective electronic module (100, 100′) to adjust a respective contributing number of cell modules (120, 120′) of at least one of the first and second groups. Each cell module (120, 120′) of the respective contributing number of cell modules (120, 120′) is contributing, positively or negatively, to the output voltage of the circuit arrangement (10).

The invention relates to the technical field of power supply equipment power control. The load power track simulation control method comprises the steps of obtaining voltage information and current information of target power supply equipment, determining power deviation information and a dynamic target voltage range generated on the basis of a preset load behavior prediction model, constructing a combined regulation and control weight vector on the basis of the power deviation information, and obtaining a load power track simulation control result. According to the combined regulation and control weight vector and the dynamic target voltage range, constructing a target power evolution trajectory curve by using a physical response inversion mechanism, executing time discretization processing on the target regulation and control trajectory curve, extracting voltage change values and current change values corresponding to each time step, and calculating the target power evolution trajectory curve; and combining the voltage change value and the current change value according to a time sequence to form a control parameter sequence, and generating an analog control instruction matched with the target power evolution trajectory curve according to the control parameter sequence. The method has the effect of improving the real-time response capability of the power supply equipment under complex working conditions.

Disclosed in the present invention are a current lookup table-based permanent magnet synchronous motor wide voltage range control method and a medium. The method comprises: by means of a full-speed domain current calibration method, obtaining a rotating speed-torque two-dimensional lookup table under a rated bus voltage; on the basis of the lookup table, multiplying a given rotating speed with a front-and-rear amplitude limiting voltage ratio to achieve wide voltage range control; and performing friction torque compensation and sampling delay compensation of a three-phase current at different rotating speeds. The present invention takes into account bus voltage fluctuation under the complex working condition of an electric vehicle, and multiplies the given rotating speed with a variable voltage coefficient ku to obtain an input rotating speed of an input current lookup table, such that precise current control of the permanent magnet synchronous motor under different bus voltage working conditions can be achieved, thereby avoiding the complex and tedious process of re-calibration of the current lookup table under different bus voltages; the present invention also takes into account friction torque compensation and phase current sampling delay compensation at different rotating speeds, wherein the friction torque compensation can be achieved by directly adding a friction torque error into a given torque signal in real time.

The invention provides an energy storage system fault diagnosis method, an energy storage system and electric equipment, and relates to the field of energy storage systems.The method comprises the steps that a fault preliminary screening result sent by a cloud server is received, and the fault preliminary screening result comprises information of an abnormal battery cluster; battery cell data of target battery cells are obtained based on the information of the abnormal battery cluster, the target battery cells are all battery cells in the abnormal battery cluster, and the battery cell data comprise voltage data and current data; the battery cell data of the target battery cell is input to a correlation model for fault diagnosis, the correlation model is used for representing the correlation between the short circuit in the battery and the capacity increment, and the method comprises the steps that the corresponding relation between the capacity increment and the voltage is determined based on the voltage data and the current data; calculating the electric leakage amount of the target battery cell in the preset voltage interval based on the corresponding relation between the capacity increment and the voltage; and determining a fault cell in the target cell based on the electric leakage amount. The method provided by the invention is helpful for improving the fault diagnosis precision of the energy storage system.

The invention relates to the technical field of battery management, and discloses a hybrid battery module equalization method and system based on battery cell health state identification, and the method comprises the steps: carrying out the multi-dimensional state fusion evaluation of a battery cell based on the voltage, temperature and total loop current of the battery cell in a battery module, and obtaining the charge state and health state of the battery cell; based on a preset voltage difference threshold value, performing threshold value judgment on the voltage range of the battery cell to obtain a diagnosis trigger signal of the battery cell; carrying out capacity cross validation on the charge state and the health state to obtain a determination result of capacity inconsistency of the battery cell; carrying out abnormal fluctuation analysis on the voltage change characteristics of the battery cells to obtain an internal resistance inconsistency judgment result of the battery cells; carrying out equalization strategy decision on the battery cell to obtain an equalization mode instruction of the battery cell; performing equalization operation on the battery cell according to the equalization mode instruction; according to the invention, the equalization rate of the hybrid battery module based on cell health state identification can be improved.

The invention relates to the technical field of energy storage battery performance detection, and discloses a performance detection device and method for an energy storage battery, and the method comprises the steps: calculating a thermal safety coefficient based on the internal temperature of the battery, the temperature gradient, the Joule heat generation rate and the environment temperature; calculating a voltage safety coefficient based on the battery end voltage, the voltage change rate and the voltage range; according to the thermal safety coefficient, the voltage safety coefficient, the battery expansion strain and the internal pressure, calculating the collaboration reflecting the multi-physical field state coordination; calculating an aging coefficient based on the accumulated current stress, the accumulated cycle index and the high stress duration of the battery; and finally, based on the collaboration, the aging coefficient and the rated current, calculating the target charging and discharging current and performing real-time adjustment. The device comprises a memory and a processor and is used for executing the method. According to the invention, multi-dimensional fusion evaluation and self-adaptive management of thermal, electrical and mechanical states and aging processes of the energy storage battery are realized, and the operation safety and service life of the battery are remarkably improved.

The invention discloses a bidirectional CLLC resonant converter with a wide input and output voltage range, and relates to the technical field of bidirectional DC / DC converters in the field of switching power supplies. According to the bidirectional CLLC resonant converter, bidirectional switching bridge arms are added to a primary circuit and a secondary circuit in a conversion main circuit respectively; the control circuit performs pulse frequency control on a switching tube in the LLC resonant network and also performs duty ratio control on the bidirectional switching bridge arm circuit, so that the gain range of the resonant converter can be further widened on the basis of performing pulse frequency control on the LLC resonant network, and meanwhile, the whole-process soft switching can be realized, and the reliability of the resonant converter is improved. And the efficiency of the converter is improved.

The invention discloses a soft switching modulation method and system for minimum current stress in a full power range. The system comprises an expansion phase shift optimization unit, an in-loop direct power control unit and a cooperative control unit. The in-loop direct power control unit is used for obtaining dynamic correction power, the expansion phase shift optimization unit is used for generating a phase shift ratio combination [D1, D2] which simultaneously meets the minimum current stress and the ZVS condition, and the cooperative control unit generates a PWM driving signal according to the generated phase shift ratio combination [D1, D2] to achieve soft switching control. According to the invention, the problem of current stress minimization in a wide voltage range can be effectively solved, the problem of ZVS loss in a light-load working condition can be prevented, and a load / voltage sudden change condition can be coped with in time; through the design of the ZVS boundary guarantee, the method is especially suitable for scenes needing wide voltage range efficient energy transmission, such as new energy grid connection and electric vehicle charging.

The embodiment of the invention provides a silicon-carbon negative electrode material and a preparation method thereof, a negative electrode plate and a battery, the silicon-carbon negative electrode material comprises a silicon-carbon inner core and a coating layer coating the silicon-carbon inner core, and the silicon-carbon inner core comprises a porous carbon substrate and nanometer silicon arranged on the porous carbon substrate. The test result of the first cyclic volt-ampere test of the silicon carbon negative electrode material meets at least one of the following conditions: (a) the value of dQ / (dV * C) of a discharge differential capacity curve in a voltage interval of 0.45 V + / -0.05 V is less than or equal to 1.7, dQ / dV represents differential capacity, the unit is mAh / V, C represents charge capacity, and the unit is mAh; (b) no sharp peak exists in a discharge differential capacity curve in a voltage interval of 0.45 V + / -0.05 V, the battery can present a smooth and stable discharge process, the capacity retention ratio and the stability of the battery after circulation are improved, and the preparation method is simple, convenient and feasible, and is suitable for industrial production.

The invention discloses a charge control method and circuit applied to a resonant conversion circuit, and electronic equipment. The charge control method comprises the following steps: acquiring an input voltage and an output voltage of the resonant conversion circuit; an adjustment output signal is obtained by using an error signal between the output voltage and the benchmark reference voltage; acquiring the amplitude change rate of the input voltage; obtaining a slope compensation slope by using the amplitude change rate; performing slope compensation on the adjustment output signal by adopting the slope compensation slope to obtain a feedback adjustment signal; generating a driving control signal by using the feedback regulation signal; and the driving control signal is sent to the resonant conversion circuit to adjust the on-off state of the resonant conversion circuit so as to adjust the output voltage. Through the above mode, the charge control method provided by the invention effectively improves the dynamic performance, avoids subharmonic oscillation under extreme conditions, dynamically adjusts the slope compensation slope in real time, and further ensures the stability in a relatively wide input voltage range.

The invention provides a diagnosis method and system suitable for magnet current in a quasi-ring symmetrical star simulator, and relates to the technical field of star simulators, and the method comprises the steps: setting a target voltage range, and finally outputting the mutual inductance coefficient, total number of turns and sectional area parameters of a coil; utilizing an electromagnetic induction conversion algorithm to generate an original measurement signal; an original measurement signal is input into an integrator through a shielded wire to obtain a proportional voltage which is strictly proportional to the current, and the proportional voltage is transmitted to a data acquisition interface; performing analog-to-digital conversion on the proportional voltage received by the acquisition interface to generate a discrete sequence, calculating a conversion coefficient by combining a target mutual inductance coefficient and a fixed time constant, and finally restoring a digital current signal; and inputting the digital current signal to an upper computer to realize dynamic waveform display, and outputting key boundary parameters to a plasma experiment module. The method has the advantages that the method can adapt to complex changes of magnet current, and enough measurement precision and response speed can be provided in a low-parameter experiment.

The invention discloses an extended double-side asymmetric phase shift modulation method for a dual-active bridge converter, and belongs to the technical field of isolated high-frequency power conversion in a power electronic technology. According to the symmetric phase shift modulation method, under the condition that the voltage conversion ratio is not matched, the zero voltage switching range of a switching tube is small, the light load efficiency is low, and variable abrupt change can occur during mode switching to cause the uncontrollable oscillation problem of inductive current. The invention provides an extended double-side asymmetric phase shift modulation method for a dual-active bridge converter in a wide voltage range. A multi-objective optimization scheme is established based on the provided modulation method, and an approximation method is provided to solve a full power range analytical solution. A smooth switching method between modes is realized, and uncontrollable oscillation of inductive current can be effectively avoided. And the conversion efficiency in a full-power range is improved.

The invention provides an energy storage system battery equalization method, system and device. The battery equalization method of the energy storage system comprises the following steps: acquiring the voltage of each battery module in the energy storage system and the first average voltage of each battery module; if the difference value between the voltage of any battery module and the first average voltage is greater than a first threshold value, determining a first battery module of which the voltage is located outside a first voltage range in the energy storage system; and discharging or charging the first battery modules until the voltage of each first battery module is within the first voltage range. By adopting the battery equalization method, the problem of inconsistency between the battery modules in the energy storage system can be accurately and efficiently solved through real-time monitoring and dynamic adjustment, equalization between the battery modules is realized, the voltage consistency of the whole battery cluster (composed of the battery modules) is further improved, and the battery equalization efficiency is improved. And accelerated performance attenuation caused by long-term over-charging or over-discharging of part of the battery modules is prevented, so that the service life of the whole energy storage system is prolonged.

The invention discloses a power conversion control method of a household energy storage system and a magnetic component, and the method comprises the steps: collecting an input voltage range, an output power demand and a frequency range according to the working characteristics of the system, selecting a nanocrystalline magnetic core material, and designing a multi-layer distributed winding structure to construct the magnetic component; acquiring operation monitoring data through a multi-dimensional data acquisition network, and generating a working condition description set through feature extraction and classification identification; a multi-target optimization model is constructed through bottleneck point identification and capacity estimation, and a power optimization distribution scheme is generated; then a control strategy selection space is constructed, an adaptive decision engine is operated, a PWM control strategy is selected, multiple PWM generation algorithms are realized, parameters are adjusted in real time, and a control signal is output; and finally, realizing system security monitoring and self-adaptive protection response through differential privacy protection processing and an anomaly detection model. According to the invention, the adaptability of the system in a wide voltage input range can be improved, and the loss of magnetic components under different load conditions is reduced.

An electrical energy recovery, storage, and distribution system that may be used in a vehicle. The system may include a supercapacitor configured to quickly store large amounts of energy. The system may also include multiple circuits operating at different voltage levels, such that an output voltage from the supercapacitor is useful over a larger voltage range and the system is more energy efficient.

The utility model discloses a grading regulation and control type voltage signal detection circuit, and belongs to the technical field of voltage signal detection. The circuit comprises a multi-stage voltage division module, a voltage division adjusting module and a signal detection end, and the multi-stage voltage division module is coupled to a detected load and used for achieving multi-gear voltage division of the voltage difference between the positive electrode and the negative electrode; the voltage division adjusting module controls access of divider resistors of different gears through a switching unit, and dynamic adjustment adapting to different voltage ranges is achieved. And the signal detection end is used for detecting and outputting the processed voltage signal. The circuit can automatically switch proper voltage division coefficients according to different load voltages, realizes wide-range high-precision voltage detection, effectively improves the stability and accuracy of voltage acquisition, improves the test quality and production efficiency of a PIV curve, and is especially suitable for test application of voltage fluctuation sensitive equipment such as a laser.

The invention relates to a voltage output method and system based on a high-voltage power supply widening controller, and belongs to the technical field of high-voltage power supplies. The method comprises the following steps: acquiring a wide-range voltage parameter, and dividing a frequency control region and a pulse width modulation control region of a high-voltage power supply through an arbitration control algorithm to obtain switching judgment information of a power supply working region; constructing a working area switching logic according to the resistance-capacitance network, executing the working area switching logic through a frequency pulse correlation algorithm, coordinating the pulse width and the working frequency, and generating a double-modulation execution signal; a closed-loop negative feedback mechanism is established, and a wide-range overvoltage-free voltage regulation and control instruction is obtained by combining a proportional-integral compensation circuit with a resistance measurement full-right control working frequency and a pulse width; and broadening the output voltage range and inhibiting the overshoot voltage through power supply power driving, coordinating the working frequency and the pulse width in combination with the wide-range overvoltage-free voltage regulation and control instruction, and outputting the wide-range voltage of the high-voltage power supply.

Provided in the present disclosure are a voltage conversion circuit, a charging station, and a control method for a charging station. The voltage conversion circuit comprises a transformer and a change-over switch module, wherein the transformer comprises a primary-side winding, a secondary-side winding and a free winding; the switch module comprises a primary-side change-over switch and a secondary-side change-over switch; a first end of the primary-side winding is used for connecting to an inverter circuit, and a second end of the primary-side winding is connected to the free winding or the inverter circuit by means of the primary-side change-over switch; a first end of the secondary-side winding is used for connecting to a rectifier circuit, and a second end of the secondary-side winding is connected to the free winding or the rectifier circuit by means of the secondary-side change-over switch; and by means of adjusting a connection state between the primary-side change-over switch and the secondary-side change-over switch, the free winding and the primary-side winding are connected in series, or the free winding and the secondary-side winding are connected in series, so as to change the turn ratio of the transformer. In the embodiments of the present disclosure, by means of controlling the states of switches, the turn ratio of a primary side to a secondary side of the transformer is bidirectionally changed in a low-cost manner, thereby expanding the output voltage range of the voltage conversion circuit.

The invention provides a CAN-FD wake-up circuit, a CAN transceiver and an electronic device, the CAN-FD wake-up circuit comprises a level shift module, an amplification comparison module and a wake-up identification module, the differential input end of the amplification comparison module is the source electrode of an NMOS tube, and the source electrode of the NMOS tube allows input of negative voltage, so the level shift module can process a CAN low level signal in a negative voltage range, and the wake-up identification module can process the CAN low level signal in the negative voltage range. Therefore, the input common-mode level range of the wake-up circuit of the CAN-FD is improved. On-off of the first switch is controlled based on whether the CAN transceiver is in a dormant state or a working state so as to control access of the second current source, and the output current of the second current source is a plurality of times of the output current of the first current source so as to increase the bandwidth of the amplification comparison module in the working state. Therefore, the amplification comparison module can be simultaneously applied to the dormant state and the working state of the CAN transceiver, so that the circuit cost is reduced.

The invention discloses a battery pack equalization method, a controller and a battery pack charging system, the battery pack equalization method is applied to a battery pack charging process, a battery pack comprises a plurality of battery cells, and the method comprises the following steps: acquiring voltage values of the plurality of battery cells; when the voltage values of the plurality of battery cells are all in a preset voltage range and meet an equalization condition, selecting a reference battery cell from the plurality of battery cells, and taking the battery cells except the reference battery cell as to-be-equalized battery cells; calculating a voltage difference value between each to-be-balanced battery cell and the reference battery cell; and balancing the corresponding to-be-balanced battery cell according to the calculated voltage difference value. Compared with the prior art, the technical scheme of the invention can reduce the deviation caused by inaccurate reference data, and improve the consistency and equalization efficiency of the full-charge tail end, thereby improving the full-charge effect and releasing the available capacity.

The invention relates to the technical field of energy storage batteries, and discloses a battery charging and discharging cut-off voltage self-adaptive adjusting method and device and a medium, the voltage range is narrowed to the second battery charging and discharging cut-off voltage range based on the preset overmatching proportion, so that the actual discharging energy of an energy storage system meets the preset condition, the overmatching capacity is utilized, and the battery charging and discharging cut-off voltage self-adaptive adjusting method and device are achieved. Premature senility caused by overuse of the battery in the initial stage is avoided, and the energy output stability in the initial operation stage of the system is guaranteed. Further, when the second rated discharge energy value is smaller than the first rated discharge energy value, determining an equal division value of a voltage range widening step according to a first battery charge-discharge cut-off voltage range and a second battery charge-discharge cut-off voltage range, and gradually widening the voltage range until the actual discharge energy is larger than the first rated discharge energy value; the target voltage range is finally obtained, the energy output capacity is automatically recovered after the battery is attenuated, manual intervention is not needed, and stable output of rated energy in the whole life cycle is ensured.

The invention discloses a high-efficiency converter for adjusting the voltage of a power grid, and belongs to the technical field of power electronics. The converter comprises a first voltage regulation circuit, a second voltage regulation circuit, a filter circuit, a detection circuit and a control circuit. By detecting the amplitude difference between the power grid voltage and the load voltage, the control circuit automatically switches the Buck working mode or the Boost working mode, and stable alternating current output in a wide input voltage range is achieved. The invention has the advantages of compact structure, high efficiency, fast response, small harmonic wave and the like, and is suitable for industrial and civil occasions with large-range fluctuation and frequent power grid voltage.

The invention provides a grid-connected and off-grid mode switching control method and device and an energy storage parallel operation system, and relates to the technical field of energy storage systems.The method comprises the steps that if the energy storage parallel operation system is not connected to mains supply within a preset voltage range, the energy storage parallel operation system is controlled to enter an off-grid mode; based on the first voltage characteristic information of the energy storage converter host, controlling the energy storage converter slave to adjust the first voltage parameter; if the electric supply in the preset voltage range is connected to the energy storage parallel operation system, controlling the energy storage converter host to enter a tracking pre-synchronization mode from an off-grid mode, controlling the energy storage converter host to track the electric supply and sequentially adjust the second voltage parameter, and controlling the energy storage converter host to track the energy storage converter host and sequentially adjust the third voltage parameter; and controlling the energy storage converter host and the energy storage converter slave to enter a grid-connected mode at the same time. According to the technical scheme, it is ensured that the voltage parameters of the host and the slave are consistent, parallel operation circulating current oscillation can be avoided to a great extent, and the possibility of system faults is reduced.

The invention discloses an electrode health diagnosis method for a silicon-carbon negative electrode battery with a self-adaptive voltage range, and relates to the technical field of battery control, and the method comprises the steps: obtaining a quasi-static open-circuit voltage discharge curve according to a low-rate discharge test of the silicon-carbon negative electrode battery in an aging process, and measuring the total battery capacity; analyzing and extracting the silicon content in the battery; reconstructing a silicon-carbon composite electrode curve according to the silicon content, and performing inversion calculation of a voltage reconstruction model to obtain electrode parameters; the method comprises the following steps: acquiring charging fragment data of a silicon-carbon negative electrode battery in a circulation process, extracting charging time sequence characteristics based on equal interval voltage alignment and relaxation voltage characteristics after full charge according to the charging fragment data, and constructing a corresponding binary mask array; and constructing an estimation model, and performing supervised learning to obtain a trained estimation model for performing diagnosis of the electrode health parameters according to the charging fragment data, thereby effectively improving adaptability and accuracy during electrode health diagnosis.

The invention discloses a transformation control method of an electronic transformer for a microwave oven, and belongs to the technical field of transformation control of electronic transformers, the method comprises the following steps: continuously collecting voltage data points through a sensor, carrying out time division according to a voltage range, and continuously obtaining use state data of an electric appliance; establishing a voltage-time relation model, fitting daily periodic fluctuation, and generating a predicted voltage fluctuation curve; before the microwave oven is used, the use time point is aligned with the voltage fluctuation curve, the predicted voltage is compared with the actual voltage of the current electric appliance use state, the voltage deviation is obtained, the obtained voltage deviation is used for correcting the preset heating power parameter, and the corrected parameter is used for rapidly switching the element to drive the electronic transformer. According to the method, the electronic transformer can adapt to power grid fluctuation in advance, the power deviation caused by voltage jump is effectively reduced by pre-judging the power grid state and adjusting the switch time sequence parameters in advance, and the control logic in different voltage scenes is optimized.

The invention discloses a flexible direct-current power transmission system and a fault ride-through method and system thereof. The flexible direct-current power transmission system comprises a main control module, and a new energy sending-out system, an alternating-current energy consumption device, a sending-end converter, a direct-current circuit breaker, a receiving-end converter and a receiving-end alternating-current power grid which are connected in sequence, the direct current circuit breaker is deployed on a direct current power transmission line between the sending end converter and the receiving end converter, and the receiving end converter is a modular multi-level converter formed by cascading a plurality of half-bridge sub-modules with damping branches; the main control module is in communication connection with the half-bridge sub-modules, the direct-current circuit breaker and the alternating-current energy consumption device and used for controlling the damping branches of the half-bridge sub-modules in the running state, the direct-current circuit breaker and the alternating-current energy consumption device to act when a direct-current fault occurs so as to restrain direct current and adjust direct-current voltage to be within a set voltage range. Therefore, no-locking fault ride-through is completed. According to the invention, high-reliability and low-cost DC fault ride-through can be realized.

The invention discloses a voltage conversion module, a chip, electronic equipment and a circuit control method, and belongs to the technical field of circuits. The voltage regulation circuit comprises a battery module and a load, and under the condition that the battery module provides a first voltage within a first preset voltage range for a voltage conversion module, the voltage conversion module is used for reducing the first voltage provided by the battery module and outputting a second voltage, maintaining the second voltage stable or maintaining the voltage reduction ratio between the first voltage and the second voltage stable; and under the condition that the battery module provides a third voltage in a second preset voltage range for the voltage conversion module, the voltage conversion module is used for boosting the third voltage provided by the battery module and outputting a fourth voltage to maintain the fourth voltage stable or maintain the boosting ratio between the third voltage and the fourth voltage stable. And the flexibility of adjusting various input voltages by the voltage conversion module is improved.

The invention relates to a method and system for extracting a flicker noise model of a high-voltage MOS device, and the method comprises the steps: designing high-voltage MOS devices of different sizes, and carrying out the measurement to obtain the DC characteristic data of each device in an operable voltage range and the flicker noise characteristic data of each device under different bias voltage conditions; based on the direct-current characteristic data, performing model fitting on the direct-current performance of the high-voltage MOS device to obtain a direct-current characteristic model, the direct-current characteristic model comprising an intrinsic current part and a collision ionization current part; and based on the direct current characteristic model and the flicker noise characteristic data, carrying out model fitting on flicker noise brought by the intrinsic current part and flicker noise brought by the collision ionization current part to obtain a flicker noise model. By fitting the noise source model associated with the magnitude of the collision ionization current, the flicker noise characteristics of the collision ionization current part are subjected to function characterization, and the flicker noise characteristic characterization precision of the high-voltage MOS device under high-voltage bias is improved.

The invention provides a method and a device for identifying a second-class short circuit state of an insulated gate bipolar transistor (IGBT), and relates to the technical field of IGBT devices. The invention aims to timely and accurately judge whether the insulated gate bipolar transistor is in the second-class short circuit state or not. The method comprises the following steps: acquiring an emitter structure of an insulated gate bipolar transistor in a test circuit; if the emitter structure does not have the auxiliary emitter, acquiring a chip gate voltage, a gate side line parasitic inductance, a gate parasitic inductance, an emitter side line parasitic inductance, a common emitter parasitic inductance, a gate current, a collector current and a current from a gate to a collector in a gate driving loop; on the basis of the Kirchhoff's voltage law, grid voltage is determined through the collected parameter data; and if the grid voltage is within the preset short-circuit voltage range, determining that the insulated gate bipolar transistor has a second-class short circuit.