811 results about "Inrush current" patented technology

The embodiment of the invention provides a closed-loop control method for power driving and protection, and the method comprises the steps: constructing a voltage feedback type circuit through a high-speed operational amplifier, and forming a closed-loop gain structure through a feedback network of the voltage feedback type circuit; the load current of the output end of the voltage feedback type circuit is monitored in real time, and when the load current exceeds a first set threshold value, a protection mechanism is triggered to turn off the output stage; the power-on surge current is limited through the soft start control circuit; phase information of a load reflection coefficient is obtained, an inductance / capacitance combination of the variable dynamic impedance matching network is selected according to phase information table look-up, inductance / capacitance parameters are switched through a relay, and the transmission standing-wave ratio between the power amplifier and a load is optimized; monitoring the temperature of the radiating fin of the power tube, and dynamically adjusting the resistance value of the feedback network; and performing cooperative control of short-circuit protection, over-temperature protection and surge suppression according to the priority. According to the embodiment of the invention, the performance bottleneck in a load fluctuation scene is broken through.

The invention relates to the technical field of power systems, and discloses a voltage regulation system of reactive power compensation equipment, which is characterized in that harmonic interference is filtered and eliminated through a voltage reactive power sensing unit, and accurate power grid parameters are acquired; a load trend pre-judgment unit analyzes the historical load curve and the real-time change trend to generate a future pre-judgment signal; the dynamic compensation calculation unit combines the current power grid state with the prediction to calculate the optimal compensation capacity and generate a switching instruction, after the hybrid switching actuator receives the instruction, a thyristor is triggered firstly to realize inrush current-free conduction, a contactor is switched to maintain low power consumption after the current is stable, and meanwhile, the compensation state monitoring unit performs closed-loop adjustment on parameter deviation, so that the optimal compensation capacity is obtained. The multi-dimensional protection unit prevents overvoltage, overcurrent and overheating, the double-path power supply guarantees continuous operation when the main power supply is abnormal, the intelligent communication unit realizes data uploading and remote cooperation, quick response switching of reactive compensation equipment and guarantee of safety of a large-scale power grid are realized, and inrush current impact in the switching process is effectively inhibited.

According to the heterogeneous multi-core chip power consumption state control system and the heterogeneous multi-core chip provided by the invention, the power consumption state request of each sub power supply domain is received through the set system hardware power consumption management module, and the driving signal is sent to the corresponding sub power supply domain according to the preset hardware time sequence, so that the corresponding sub power supply domain enters the target state; generating a PMU control signal; and the power management module drives an internal voltage regulator to execute corresponding regulation operation according to the PMU control signal. A special control processor (SCP) is not needed, the system hardware power consumption management module realized by pure hardware is adopted to directly control the power consumption state of each sub power supply domain in the heterogeneous multi-core SoC, the software processing delay is eliminated, the response speed is high, the static power consumption of the power consumption management module is remarkably reduced, and the system is particularly suitable for an ultra-low power consumption scene and has a wide application prospect. And hardware-level surge current protection is realized in a multi-core power-on process.

A system for providing inrush current limiting for induction motor starting. The system utilizes a pre-start controller to initialize operation of a controller including multiple switches for controlling the voltage delivered to a motor having multiple phases. The pre-start controller activates each switch and determines whether a phase current flowing through the switches satisfies a threshold current. The switches are deactivated a phase current satisfies the threshold current. The pre-start controller determines an activation order for each phase and orders phases having higher phase currents higher in the order than lower phase currents, and determines an activation timing. Based on whether the highest phase current is positive or negative, the pre-start controller then activates, using a voltage at a corresponding angle and based on the activation order and activation timing, the phases to de-saturate the flux generated by the phase currents, thereby limiting an inrush current provided to the motor.

The invention discloses a power distribution network island grid-connected smooth switching control method and system, belongs to the field of power distribution networks, and particularly relates to power distribution system control, and the method comprises the steps: carrying out the feature extraction of a first voltage signal at the island side of a power distribution network and a second voltage signal at the main network side of the power distribution network, and obtaining a quantitative feature value; inputting the quantized characteristic value into an inrush current prediction model to output a closing inrush current prediction range, calculating a width value and a peak amplitude of the prediction range corresponding to each phase time sequence to identify a target phase interval, and evaluating stability contribution of each phase time sequence in the target phase interval to determine a target closing time sequence; and adjusting the output characteristic parameters of the inverter according to the target closing time sequence to obtain an inverter output signal, performing iterative optimization to adjust phase difference compensation, and generating a grid-connected control instruction to control grid-connected smooth switching of the power distribution network island, so that smooth switching during grid connection of the power distribution network island and the main network can be realized, and the stability of the power distribution system is improved.

The invention discloses a power type negative temperature coefficient thermistor and method for suppressing surge current, and relates to the technical field of negative temperature coefficient thermistors, the thermistor comprises a core body and pins, the pins are respectively arranged on electrodes on two sides of the core body by adopting a multi-contact-surface structure, and the pins are arranged on the two sides of the core body. The core body is made of a Mn-Co-Ni-La oxide with a nano composite gradient structure; the Mn-Co-Ni-La oxide with the nano-composite gradient structure determines the upper limits of core capabilities such as surge suppression, wide temperature stability and low power consumption of the thermistor, and the redesign of the pin is the key of performance transfer, so that the electrical properties (low contact resistance and high surge tolerance) of the Mn-Co-Ni-La oxide with the nano-composite gradient structure are not counteracted by structural defects; the arrangement of the bracket prevents the Mn-Co-Ni-La oxide with the nano-composite gradient structure from losing the effect due to heat accumulation and physical damage through thermal management and mechanical protection, and the three components supplement one another and cooperate with one another, so that the performance of the thermistor of the Mn-Co-Ni-La oxide with the nano-composite gradient structure is guaranteed.

The invention belongs to the technical field of power transformation equipment, and particularly relates to a low-voltage dynamic reactive compensation switching device which comprises a shell, a photoelectric isolation module and a communication module. The shell is in an inverted-T shape, a switching switch is arranged at the front end of the shell, wiring ports are symmetrically formed in the upper side and the lower side of the shell, and wiring bolts are installed on the wiring ports. A photoelectric isolation module is arranged on one side of the shell, and the heat dissipation holes dissipate heat for the photoelectric isolation module. According to the scheme, a thyristor and contactor hybrid switching switch is adopted, zero-crossing switching is realized by the thyristor during dynamic load fluctuation, and inrush current control is less than or equal to 10 times of rated current. And when the static state is stable, the contactor is automatically switched to be conducted, and the power consumption is reduced to 1.5 W and is greatly reduced compared with a pure thyristor scheme, so that the impact is avoided and the energy consumption is reduced. The thyristors are in bidirectional anti-parallel connection, and are matched with zero-cross detection logic of the controller, so that overvoltage and transient harmonic waves in the switching process are thoroughly eliminated, no interference is caused to a power grid, and the service life of the device and power grid equipment is prolonged.

The utility model discloses a soft start system based on excitation current reduction, which is characterized in that a time relay mainly controls the switching of a live wire between a power resistor and an alternating current contactor, the power resistor magnetizes a transformer at the moment of electrification, and the alternating current contactor is connected into a circuit by the time relay after the magnetization is completed; and after the power resistor is short-circuited, the circuit is cut out, so that the purpose of suppressing the excitation inrush current is finally achieved, the excitation effect caused by voltage abrupt change at the power-on moment of the isolation transformer can be avoided, and the excitation abrupt change of the isolation transformer during power-on is effectively reduced.

The utility model provides a pre-charging circuit and an energy storage power supply. The pre-charging circuit comprises a constant current driving module, a pre-charging switch module, a power supply switch module and a voltage conversion module; the constant current driving module is respectively connected with the pre-charging switch module and the photovoltaic power supply, the pre-charging switch module is also connected with the voltage conversion module, and the power supply switch module is respectively connected with the photovoltaic power supply and the voltage conversion module; the constant-current driving module is used for outputting a constant-current signal when the input voltage of the photovoltaic power supply is greater than or equal to a first preset voltage so as to drive the pre-charging switch module to work, so that the photovoltaic power supply pre-charges a capacitor in the voltage conversion module through the pre-charging switch module; the power supply switch module is used for conducting when the voltage of the capacitor is greater than a preset value, so that the photovoltaic power supply supplies power to the voltage conversion module through the power supply switch module. According to the circuit, the surge current at the initial stage of capacitor charging can be reduced, meanwhile, smooth transition from pre-charging to normal power supply can be achieved, and the safety and stability of the circuit are improved.

The embodiment of the invention discloses a power distribution network intelligent grounding inrush current suppression method and device, and the method comprises the steps: collecting the state data of a power distribution network, and generating a line state data set, the state data comprising real-time load characteristics and impedance parameters; analyzing the line state data set based on an edge calculation model, and predicting an inrush current peak value and a waveform characteristic of the inrush current peak value at the grounding moment in combination with a nonlinear load fluctuation characteristic caused by the access of a distributed power supply; a particle swarm optimization model is constructed according to the predicted inrush current peak value, waveform characteristics and load characteristics, a search space is constrained through a local heuristic rule, capacitance and resistance parameters of an RC damping loop are dynamically adjusted, and an optimal damping scheme is generated; on the basis of inter-phase cooperative control logic of a three-phase system, dynamically determining grounding trigger time sequences of all phases in combination with the predicted inrush current waveform characteristics; and a grounding instruction is sent to the three-station integrated mechanism, and the three-station integrated mechanism executes an inrush current suppression operation. According to the invention, efficient inrush current suppression is realized.

The invention discloses an adaptive virtual impedance-based fault current limiting method for a network-forming converter, and belongs to the technical field of converter control. Comprising the following steps: collecting grid-side voltage, converter-side voltage and converter output current; carrying out current amplitude calculation on the grid-side voltage quantity to obtain a current effective value of the port of the converter; judging whether the current effective value of the current transformer port exceeds a current threshold value of the current transformer; and if yes, self-adaptive virtual impedance is introduced to carry out converter fault current limitation. The resistance part of the virtual impedance is used for suppressing surge current at the beginning of a fault; and the reactance part is used for suppressing the effective value of the fault transient current within the current limiting range. In the fault process, the current virtual impedance value is adaptively changed according to the effective value of the current overcurrent, and the virtual impedance can be automatically quitted after the fault end stage. The method is suitable for fault current suppression of the network-forming converter in various control modes, and has good feasibility and practical value.

The invention discloses a composite switch for reactive compensation capacitor bank switching and a control method thereof, and relates to the technical field of capacitor switching, and the method comprises the steps: detecting the capacity and switching data of each branch in a back-to-back capacitor bank through a reactive compensation controller, and determining a group capacitor to be subjected to switching operation according to a preset switching control condition; the reactive compensation controller determines the switching time sequence of each phase of each group capacitor according to the confirmed input / output operation instruction to be executed and the reference voltage of each group capacitor; and calculating the reactive state and the switching state of the switched power system through the reactive compensation controller. Compared with a conventional switching control method, the automatic phase selection switching control method has the advantages that closing inrush current and overvoltage are lower, the accuracy of phase control switching of the capacitor bank can be improved, high-frequency inrush current and pre-breakdown arcing phenomena can be reduced, meanwhile, the probability of rebreakdown can be reduced, and the service life of the capacitor bank can be prolonged. And the performance of the composite switch switched capacitor bank is improved.

The invention relates to a magnetizing inrush current detection method and device, computer equipment, a readable storage medium and a program product. The method comprises the following steps: collecting a current signal of a transformer port; determining a time domain characteristic parameter, a frequency domain characteristic parameter and a time-frequency domain characteristic parameter of the current signal; determining importance parameters and correlation parameters of the time domain characteristic parameters, the frequency domain characteristic parameters and the time-frequency domain characteristic parameters; selecting a target characteristic parameter from the time domain characteristic parameter, the frequency domain characteristic parameter and the time-frequency domain characteristic parameter according to the importance parameter and the correlation parameter, and constructing a target characteristic vector of the current signal by using the target characteristic parameter; and adopting a pre-trained classification model to generate an excitation surge current detection result of the transformer port based on a comparison result of the target feature vector and a pre-stored excitation surge current feature. By adopting the method, the multi-dimensional characteristics of the current signal in the time domain, the frequency domain and the time-frequency domain can be fully utilized to improve the recognition precision and speed of the excitation surge current.

The utility model discloses a power supply input surge protection and isolation device, which comprises a piezoresistor, a surge decoupling power resistor and a TVS (Transient Voltage Suppressor) tube which are sequentially connected in series, and a self-adaptive surge control circuit which is connected with the surge decoupling power resistor in parallel, when surge overvoltage occurs, the TVS tube is firstly broken down, and transient large current flows through the adaptive surge control circuit; the surge decoupling power resistor is used for enabling the passing surge current to generate relatively large voltage drop after the TVS tube is broken down; the self-adaptive surge control circuit comprises a first MOS tube which is used for conducting transient large current passing through a TVS (Transient Voltage Suppressor) tube; when the voltage drop on the MOS tube is greater than the breakdown voltage of the voltage-regulator tube, the voltage-regulator tube is broken down to trigger the conduction of the triode; when the voltage-regulator tube is broken down, the triode is conducted, so that the GS voltage drop of the first MOS tube is reduced, and the first MOS tube is turned off; when the sum of the clamping voltage of the TVS tube end and the voltage drop of the surge decoupling power resistor exceeds the minimum action voltage of the piezoresistor, the piezoresistor acts, so that high-energy transient interference flows through the piezoresistor, and surge protection is realized. According to the utility model, the surge protection and isolation protection functions of the input end of the power supply can be effectively realized, and the safety and stability of the use of the power supply are ensured.

The invention discloses a pre-synchronization control method for a network-building converter based on a virtual synchronous generator, and the method comprises the steps: collecting the three-phase voltage of the output end of the virtual synchronous generator VSG and the three-phase voltage of a power grid side, converting the three-phase voltage into a voltage component in a two-phase static coordinate system through Clark conversion, and extracting a positive-sequence component; calculating a phase difference compensation coefficient based on the positive sequence component; based on the phase difference compensation coefficient, adaptively setting a PI parameter; and calculating and adjusting the amplitude of the internal potential to finish pre-synchronization. In the working process, through self-adaptive PI parameter setting and amplitude accurate judgment, the pre-synchronization time is shortened, the grid-connected impact current is reduced, and the grid-connected success rate of the micro-grid in a weak grid scene is improved.

A battery pack charger may include a housing. The battery pack charger may include a battery pack interface provided on the housing and configured to removably receive a battery pack. The battery pack charger may include a power input. The battery pack charger may include an LLC converter including a dual transformer electrically connected between the power input and the battery pack interface. The battery pack charger may include a power factor correction (PFC) boost converter electrically connected between the power input and the battery pack interface. The battery pack charger may include an input inrush current control circuit electrically connected between the PFC boost converter and the battery pack interface.

The embodiment of the invention provides a photovoltaic loss reduction device, a switching-on control method, electronic equipment and a storage medium, and belongs to the technical field of circuit breaker switching-on. The device comprises a vacuum circuit breaking module, an inrush current suppression module and an overvoltage limiting module. Step-by-step closing of the inrush current suppression module is controlled at an optimal closing phase angle before closing and pre-discharging of the vacuum circuit breaking module, step-by-step control is performed on primary on-off of a load and an external photovoltaic power grid, steady-state closing of the vacuum circuit breaking module is realized, and a large-scale photovoltaic power station is basically free of inrush current during no-load closing and directly enters steady-state excitation current; the overvoltage generated by the vacuum circuit breaking module is limited through the overvoltage limiting module, and the problem of overvoltage caused by reignition of the circuit breaking module when the capacitor is cut off is effectively solved. During power generation in the daytime, the photovoltaic power grid and the load power grid are subjected to accurate phase selection closing or non-impact access, so that the off-grid no-load loss of the photovoltaic power station which does not generate power at night and in rainy days is effectively reduced.

The invention discloses a high-side driving circuit and a vehicle body controller. The high-side driving circuit relates to the field of vehicle body controllers, and solves the problem that the existing high-side driving circuit cannot meet the requirements of low cost and high reliability. The switching circuit adopts a combined structure of switching tubes and is connected in series between a power supply and a load, and more stable on-off control is realized through cooperation of multiple tubes; the starting threshold circuit responds to an external control signal only when the load impedance meets a preset threshold value, and large-current load driving in the starting stage or forced starting during load abnormity is carried out. The over-current threshold circuit is connected in series with a driving loop of the switching circuit and provides constant over-current turn-off. A voltage negative feedback circuit is introduced into the voltage and potential stabilizing module to realize self-turn-off and keep a turn-off state when overcurrent and short circuit occur, and self-recovery is realized after a fault disappears without depending on logic judgment of an external control unit. The port protection module absorbs the instantaneous high voltage and the surge current. Through the characteristics, the current-carrying capability of the triode is improved, and the application range of the triode switching circuit is widened.

The utility model discloses a surge protection circuit, a power supply circuit and electronic equipment, and the surge protection circuit comprises an energy storage circuit which is used for being coupled with a power supply input circuit and a load circuit so as to receive a power supply input signal provided by the power supply input circuit, and outputting a load power supply signal to the load circuit; the surge suppression circuit is coupled with the energy storage circuit; a bypass tank circuit coupled to the tank circuit and the surge suppression circuit; and the bypass switch circuit is coupled with the energy storage circuit, the surge suppression circuit and the bypass energy storage circuit, and the bypass switch circuit is configured to store energy for the bypass energy storage circuit by using the power input signal when the load power supply signal is lower than a first set threshold value so as to limit the load power supply signal within a second set threshold value. By means of the scheme, the surge protection circuit can effectively restrain the surge current from damaging related circuits, and effectively restrain the surge current from being generated when power input is interrupted for a short time and then recovered, so that it is guaranteed that a load circuit maintains normal work and operation.

The invention relates to a relay phase selection pull-in control method. The method comprises the following steps: acquiring a first phase voltage zero crossing point, a second phase voltage zero crossing point and a third phase voltage zero crossing point; speculating pull-in voltage zero crossing points of the first soft start relay and the second soft start relay based on the third phase voltage zero crossing point, and speculating pull-in time delay of the first soft start relay and the second soft start relay based on the pull-in voltage zero crossing points; speculating a first pre-charging zero crossing point based on the first phase voltage zero crossing point, and speculating the pull-in time delay of the first main power relay based on the first pre-charging zero crossing point; and a second pre-charge zero crossing point is speculated based on the second phase voltage zero crossing point, and the pull-in time delay of the second main power relay is speculated based on the second pre-charge zero crossing point. Inrush current can be suppressed, loss is reduced, and the service life of the relay is prolonged.

The invention relates to the technical field of power supply or power distribution circuit devices of power systems, and discloses a power distribution loop self-reset state control system based on thermal parameter feedback, which comprises a thermal parameter acquisition module used for acquiring a physical heat dissipation temperature sequence of a power supply node after tripping; the historical load mapping module is used for calculating a closing transient temperature rise estimated value according to the load characteristic data within 24 hours before tripping and generating a dynamic correction value of a heat dissipation slope judgment boundary; the logic arbitration module is used for calculating the deviation degree of the heat dissipation slope of the double-window sampling sequence and judging whether the deviation degree is converged into a heat dissipation slope judgment boundary updated according to the dynamic correction amount or not; according to the invention, through a closed loop arbitration mechanism of a heat dissipation characteristic slope, a physical heat dissipation steady state inflection point is identified, a maloperation risk caused by environment thermal resistance drift and closing inrush current impact is eliminated, and power supply continuity is guaranteed.

The present disclosure is directed to a rack power distribution unit (RPDU) that automatically and safely switches power to one or more receptacles. The RPDU includes one or more processors utilizing control algorithms that manage bistable relays so that in-rush current is minimized upon manual connection / disconnection of power to a load device. In particular, relay contact status (open / closed) is identified based on changes in RMS or peak voltage influenced by the load impedance. The RPDU is also configured to predict timings for voltage zero-crossing events. In this manner, and based on the determination of relay contact status and voltage zero-crossing prediction, open relay contacts are identified and safely closed at voltage zero-crossing.

Provided are an uninterruptible power supply (UPS), a method and an apparatus for soft starting the UPS, and a controller. In the UPS, an inverter circuit is provided with three-phase output terminals, and two output terminals of a pre-charge circuit are electrically connected to output terminals of any two phases, respectively. The UPS charges a bus capacitor through an energy storage operation and a freewheeling operation, so that a voltage of the bus capacitor is greater than a peak value of a mains power. When the mains relay is powered on, a voltage of an end of the mains relay that is electrically connected to the mains power is lower than the voltage of the bus capacitor. Due to limitation of a conduction direction in a rectification circuit, no inrush current occurs, thereby reducing arcing of relay contacts and improving stability of the UPS during a power-on process.

The invention provides a high-power power supply AC-DC switch surge current suppression method and system and related equipment, and relates to the technical field of switching power supplies, and the method comprises the steps: carrying out the parameter initialization after a power supply system is powered on, obtaining a surge current suppression parameter, and starting an nth AC-DC power module in N AC-DC power modules; the method comprises the following steps: monitoring total input current on an alternating current input bus of a power supply system in real time, and circularly executing the following operations until N AC-DC power modules are all started: determining whether the nth AC-DC power module enters a steady-state operation state or not; when it is determined that the nth AC-DC power module enters the steady-state operation state, and n is smaller than N, whether the n AC-DC power modules enter the steady-state operation state or not is determined; and under the condition that it is determined that all the n AC-DC power modules enter the steady-state operation state, performing cooperative suppression operation on the (n + 1) th AC-DC power module in the N AC-DC power modules according to the surge current suppression parameters so as to start the (n + 1) th AC-DC power module.

The invention discloses an improved hybrid clamping three-level structure and a loss suppression method, and aims to suppress surge current and reduce switching loss by introducing a buffer inductor between a DC bus capacitor and the midpoint of a clamping diode, and maintain the inherent voltage self-balancing capability of the topology at the same time. Experimental verification shows that the surge current can be reduced to the level close to the load current, the turn-on loss is averagely reduced by 23%, and the reliability and efficiency of the series-connected SiC MOSFETs in medium-voltage direct-current application are remarkably improved.

The invention relates to the technical field of relay protection, in particular to a method for identifying excitation surge current of a transformer sent out by a wind power plant based on differential current waveform characteristics and application of the method. Compared with a traditional second harmonic braking method, the method has the advantages that the time window is short, the magnetizing inrush current of the transformer can be quickly identified, and the protection reliability of the sending-out transformer of the wind power plant is improved. The objective of the invention is to solve the problem of how to reliably identify the magnetizing inrush current fault of the wind power plant transformer.

The invention discloses a distribution line protection method, device and equipment with an excitation inrush current identification function, and a storage medium. The method comprises the following steps: collecting a current signal and a voltage signal of a distribution line in real time; the current signal is used for harmonic component extraction, and the voltage signal is used for constructing an auxiliary criterion variable; the position state of the circuit breaker is monitored in real time, the current closing / tripping state of the circuit breaker is judged to trigger a closing event, and an inrush current recognition mode is started; and on the basis of the inrush current identification mode, the excitation inrush current condition is judged in combination with a multi-feature criterion, and the distribution line is protected. On the basis of existing over-current protection function configuration, secondary harmonic content judgment logic is added, based on the characteristics that the secondary harmonic content of magnetizing inrush current is high, bus voltage is normal and waveform is asymmetric, line misoperation caused by the magnetizing inrush current is prevented through the secondary harmonic content, meanwhile, a voltage criterion is added to avoid faults and inrush current, and therefore the over-current protection function is achieved. While the overcurrent protection action is ensured to quickly cut off the fault, the protection misoperation caused by inrush current during switching on can be prevented.

The invention relates to the technical field of digital ring main unit power distribution operation regulation and control, and discloses an intelligent power distribution operation regulation and control system of a digital ring main unit, which comprises a state sensing module, a logic judgment unit and an execution regulation and control module, the logic discrimination unit identifies a feeder power distribution state according to the power flow distribution data and generates a topology reconstruction scheme; the execution regulation and control module drives a switch to act, migrates the feeder loop to a target bus section, forms transition impedance by using closing pre-breakdown current during migration, inhibits transient inrush current, drives an impedance compensation branch to access according to a zero-sequence current vector of the feeder loop, and counteracts neutral point potential drift by using potential bias generated by reactive power injection; according to the method, the power distribution topology is converted from static hard connection to logic remapping, circuit transient state physical process reconstruction and stock hardware redundancy mining are utilized, node power vector balanced distribution is achieved under the condition that the feeder line continuous power receiving state is maintained, and power flow randomness conflicts are eliminated.

The invention discloses a circuit for a high-voltage direct-hanging electric heater, and the circuit comprises a high-voltage pre-charging module which is used for inputting high-voltage alternating current and suppressing the surge current of the high-voltage alternating current; the full-bridge rectifier module is used for converting the high-voltage alternating current into direct current; the conversion and control module is used for isolating and converting the direct current and outputting rated voltage and required power of the electric heater based on the direct current, the full-bridge rectifier module is connected with the high-voltage pre-charging module and the conversion and control module, and the output end of the conversion and control module is connected with the electric heater.

The invention belongs to the technical field of power semiconductor devices. The invention provides a SiC MOSFET surge current transient electrothermal coupling failure modeling method. A real packaging three-dimensional structure model is established, and material parameters are defined; dividing grids, constructing a current and solid heat transfer module, applying surge waveform data and realizing real-time coupling; carrying out transient solution to obtain temperature data, extracting a hot spot area and comparing thermodynamic critical parameters of the material; and establishing a multi-class failure mechanism model, and outputting a failure prediction result and reliability evaluation. The method is high in structural reduction degree, transient temperature rise and hot spot distribution can be accurately simulated, the problems that modeling is not accurate, transient electrothermal coupling analysis is lacked and a real failure mode cannot be reflected in the prior art are solved, the failure position, mode and threshold value can be accurately predicted, the method is suitable for reliability evaluation under the multi-surge condition, and the method is suitable for popularization and application. And the method has engineering application value and research significance.