MOSFET electrical parameter self-adaptive adjusting system and method for electric vehicle

Abstract

The invention discloses an MOSFET electrical parameter self-adaptive adjustment system and method for an electric vehicle, and relates to the technical field of electrical parameter self-adaptive adjustment. The MOSFET electrical parameter self-adaptive adjustment system for the electric vehicle comprises a parameter acquisition module; a parameter adjustment value acquisition module; a control execution module; and an MOSFET module. According to the method, the key electrical parameters and the MOSFET electrical parameters of the to-be-adjusted electric vehicle are obtained in real time within the preset time period to obtain the electrical adjustment evaluation index, and then the driving circuit of the to-be-adjusted electric vehicle is dynamically adjusted; and finally, based on the gate-source voltage, whether the gate-source voltage is adjusted until the electrical adjustment value is equal to 0 is judged, so that more accurate adjustment of the electrical parameters of the MOSFET is realized, and the problem of insufficient utilization of the relevance between the electrical parameters of the MOSFET and the key electrical parameters in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of electrical parameter self-adaptive regulation, and in particular to a MOSFET electrical parameter self-adaptive regulation system and method for electric vehicles. Background Art

[0002] With the world's increasing attention to environmental protection and energy transformation, the electric vehicle industry has experienced explosive growth in recent years. As a representative of new energy vehicles, electric vehicles have seen an ever-expanding market demand and an accelerated technological iteration, which has put forward higher performance requirements for core components such as motor controllers and battery management systems.

[0003] Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is a key component in the field of power electronics. Its performance directly affects the efficiency and reliability of core components such as electric vehicle drive systems and battery management systems. Traditional fixed-parameter MOSFETs can no longer meet the efficiency, reliability and safety requirements of electric vehicles under different operating conditions. Therefore, in the MOSFET electrical parameter adaptive adjustment system, intelligent and adaptive control technology needs to dynamically adjust the electrical parameters of MOSFET according to the driving conditions and load changes of electric vehicles, so as to achieve the optimal working performance and energy efficiency ratio.

[0004] The existing MOSFET electrical parameter adaptive adjustment method obtains real-time data by real-time monitoring of the operating status of the electric vehicle and performs data analysis and processing. Then, a mathematical model is established through the controller to describe the performance of MOSFET under different working conditions. Finally, the mathematical model is optimized according to the feedback mechanism to evaluate the adjustment strategy, thereby realizing real-time monitoring and adaptive adjustment of MOSFET electrical parameters.

[0005] For example, the adaptive resonant WPT system based on negative energy feedback disclosed in the patent application with publication number CN117458736A includes: a resonant network and a reactive power pickup circuit; the resonant network includes a transmitting network and a receiving network; the transmitting network is provided with an excitation power supply, a transmitting end resonant capacitor, a transmitting coil and a transmitting end resistor in series in sequence; the reactive power pickup circuit includes a rectifier capacitor, a third MOSFET tube and a second MOSFET tube, and the third MOSFET tube and the fourth MOSFET tube are connected in series and in parallel with the rectifier capacitor; reactive power negative feedback is achieved by adjusting the conduction and phase of the third MOSFET tube and the fourth MOSFET tube, thereby achieving adaptive resonance of the WPT system.

[0006] For example, the patent application with publication number CN110829558A discloses a universal electric tool charger with intelligent adaptive control, including: controlling the conduction or cutoff of the switch tube through a PWM / PFM control module; connecting the switch MOSFET and the charging port of the electric tool to be charged in sequence through the rectifier / filter module in the AC / DC power conversion module, and the voltage / current dual feedback loop is respectively connected to the current sampling circuit, the voltage sampling circuit, and the charging parameter matching control network; the current sampling circuit and the voltage sampling circuit are respectively connected to the loop connecting the rectifier / filter module and the switch MOSFET; the charging parameter matching control network is sequentially connected to the lithium battery module charging management module, the lithium battery module type identification module, and the charging port, and the lithium battery module charging management module is connected to the switch MOSFET; the lithium battery module charging management module is connected to the charging port through the switch MOSFET control output terminal.

[0007] However, in the process of implementing the technical solution of the invention in the embodiments of the present application, the present application found that the above technology has at least the following technical problems:

[0008] In the prior art, the application environment of MOSFET in electric vehicles is complex and changeable, which makes it difficult to quickly apply the mathematical model describing the performance of MOSFET. As a result, during the electrical parameter adjustment process, it is impossible to adjust the parameters of MOSFET in real time to improve the performance of MOSFET. There is a problem of insufficient utilization of the correlation between MOSFET electrical parameters and key electrical parameters. Summary of the invention

[0009] The embodiments of the present application solve the problem of insufficient utilization of the correlation between MOSFET electrical parameters and key electrical parameters in the prior art by providing a MOSFET electrical parameter adaptive adjustment system and method for electric vehicles, thereby achieving more precise adjustment of MOSFET electrical parameters.

[0010] The embodiment of the present application provides a MOSFET electrical parameter adaptive adjustment system for electric vehicles, comprising: a parameter acquisition module, a parameter adjustment value acquisition module, a control execution module and a MOSFET module; wherein the parameter acquisition module is used to acquire key electrical parameters of the electric vehicle to be adjusted and MOSFET electrical parameters in real time within a preset time period, the key electrical parameters include on-resistance, actual drive current and actual drive voltage, and the MOSFET electrical parameters include on-resistance, drain current and gate voltage; the parameter adjustment value acquisition module is used to acquire an electrical adjustment value according to the actual operating state of the electric vehicle to be adjusted within a preset time period; the control execution module is used to acquire an electrical adjustment evaluation index according to the electrical adjustment value, and judge whether to perform dynamic adjustment of electrical parameters on the MOSFET drive circuit of the electric vehicle to be adjusted based on the electrical adjustment evaluation index and the corresponding preset threshold range, the electrical adjustment evaluation index is used to measure the matching degree between the electrical adjustment value and the electrical adjustment value to be adjusted; the MOSFET module is used to monitor the gate-source voltage in the dynamic adjustment process in real time when performing dynamic adjustment of electrical parameters, and judge whether to adjust the gate-source voltage until the electrical adjustment value is equal to 0 based on the gate-source voltage.

[0011] Furthermore, the electrical adjustment value is obtained according to the actual operating state of the electric vehicle to be adjusted within a preset time period, and the following steps are also included before: real-time monitoring of the conduction process of the MOSFET to obtain conduction parameters, combining the obtained conduction parameters with the reference on-state resistance value to obtain a conduction performance score, the conduction performance score is used to reflect the stability of the conduction performance of the MOSFET during the conduction process, and the conduction performance score is calculated by the following formula:

[0012]

[0013] Where q is the number of the preset time period, q = 1, 2, ..., Q, Q is the total number of preset time periods, e is a natural constant, YIN q represents the conductivity performance score of MOSFET in the qth preset time period, δ represents the ambient temperature influence factor, represents the on-resistance value in the qth preset time period, Indicates the reference on-resistance value, Z1 q It represents the working carrier concentration of MOSFET in the qth preset time period, Z2 q It represents the working carrier mobility of MOSFET in the qth preset time period.

[0014] Further, the obtained conductive parameters are combined with the reference on-state resistance value to obtain the conductive performance score, and then the following steps are also included: real-time monitoring of the on-time parameters of the MOSFET, combining the monitored on-time parameters with the obtained conductive performance score and the rated drive current and rated drive voltage to obtain the on-state control score, the on-time parameters including the on-time and the off-time, the on-state control score is used to reflect the performance of the MOSFET in the on-state within a preset time period, and the on-state control score is calculated by the following formula:

[0015]

[0016] In the formula, DAO q It represents the conduction state control fraction of MOSFET in the qth preset time period, represents the turn-on time of MOSFET in the qth preset time period, It represents the turn-on delay time of MOSFET in the qth preset time period, It represents the current rise time of MOSFET in the qth preset time period, It represents the voltage drop time of MOSFET in the qth preset time period. represents the off time of MOSFET in the qth preset time period, It represents the turn-off delay time of MOSFET in the qth preset time period. It represents the voltage rise time of MOSFET in the qth preset time period, represents the current falling time of MOSFET in the qth preset time period, T0 represents the preset duration stamp, L0 represents the rated drive current, L q represents the actual driving current of the electric vehicle to be adjusted in the qth preset time period, Y0 represents the rated driving voltage, Y q It represents the actual driving voltage of the electric vehicle to be adjusted in the qth preset time period.

[0017] Further, the on-state control score is obtained, and then the following steps are included: judging whether the on-state control score within a preset time period is equal to the on-state reference control score, if so, continuing to monitor the on-state of the MOSFET within the preset time period in real time, otherwise adjusting the on-time parameter of the MOSFET according to the obtained deviation, wherein the deviation is the difference between the on-state reference control score and the on-state control score; the specific process of adjusting the on-time parameter of the MOSFET is as follows: step 1, judging whether the on-time is greater than the off-time, and if so, obtaining a first time difference and reducing the on-time direct current according to the first time difference until the on-time is equal to the off-time, otherwise execute step 2, wherein the first time difference is the difference between the on-time and the off-time; step 2, determine whether the on-time is less than the off-time, if so, obtain the second time difference and reduce the off-time according to the second time difference until the off-time is equal to the on-time, otherwise execute step 3, wherein the second time difference is the difference between the off-time and the on-time; step 3, reduce the duration of the on-time and the off-time until the duration of the on-time and the off-time is equal to the preset duration; step 4, recalculate the on-state control score according to the on-time parameter of the adjusted MOSFET until it is equal to the on-state reference control score.

[0018] Furthermore, the electrical adjustment value is obtained according to the actual operating state of the electric vehicle to be adjusted within a preset time period, and then the deviation evaluation index is obtained. The specific acquisition steps are: real-time monitoring of the on-frequency and on-temperature of the MOSFET, and combining the monitored on-frequency and on-temperature with the deviation weight factor, on-frequency weight factor and on-temperature weight factor obtained from a preset database to obtain the deviation evaluation index. The deviation evaluation index is used to quantify the degree of impact of the on-state of the MOSFET within a preset time period.

[0019] Furthermore, the electrical adjustment evaluation index is calculated by the following formula:

[0020]

[0021] Where TIAO q represents the electrical adjustment evaluation index of MOSFET in the qth preset time period, β represents the deviation evaluation index correction factor, and J q represents the resistance adjustment value of MOSFET in the qth preset time period, J0 represents the resistance adjustment value to be adjusted, K q represents the current adjustment value of MOSFET in the qth preset time period, K0 represents the current adjustment value to be adjusted, H q It represents the voltage adjustment value of MOSFET in the qth preset time period, and H0 represents the voltage adjustment value to be adjusted.

[0022] Furthermore, the specific process of dynamically adjusting the electrical parameters of the MOSFET drive circuit of the electric vehicle to be adjusted is: obtaining the positive deviation and negative deviation of the electrical adjustment evaluation index, the positive deviation is a deviation value less than a preset threshold range, and the negative deviation is a deviation value greater than the preset threshold range; sending the adjustment instruction to the PWM controller to adjust the MOSFET electrical parameters and recalculate the electrical adjustment evaluation index until the electrical adjustment evaluation index is within the corresponding preset threshold range.

[0023] The embodiment of the present application provides a method for adaptively adjusting electrical parameters of MOSFET for electric vehicles, comprising the following steps: S1, acquiring key electrical parameters of the electric vehicle to be adjusted and MOSFET electrical parameters in real time within a preset time period, wherein the key electrical parameters include on-resistance, actual drive current and actual drive voltage, and the MOSFET electrical parameters include on-resistance, drain current and gate voltage; S2, acquiring an electrical adjustment value according to the actual operating state of the electric vehicle to be adjusted within the preset time period; S3, acquiring an electrical adjustment evaluation index according to the electrical adjustment value, and judging whether to perform dynamic adjustment of electrical parameters on the MOSFET drive circuit of the electric vehicle to be adjusted based on the electrical adjustment evaluation index and the corresponding preset threshold range, wherein the electrical adjustment evaluation index is used to measure the degree of matching between the electrical adjustment value and the electrical adjustment value to be adjusted; S4, monitoring the gate-source voltage in the dynamic adjustment process in real time when performing dynamic adjustment of the electrical parameters, and judging whether to adjust the gate-source voltage based on the gate-source voltage until the electrical adjustment value is equal to 0.

[0024] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0025] 1. An electrical adjustment value is obtained by obtaining the key electrical parameters of the electric vehicle to be adjusted and the electrical parameters of the MOSFET, and an electrical adjustment evaluation index is obtained based on this, and then it is determined whether to perform dynamic adjustment of the electrical parameters of the MOSFET drive circuit of the electric vehicle to be adjusted, and finally it is determined based on the gate-source voltage whether to adjust the gate-source voltage until the electrical adjustment value is equal to 0, thereby improving the accuracy of dynamic adjustment, and then achieving more precise adjustment of the MOSFET electrical parameters, effectively solving the problem of insufficient utilization of the correlation between the MOSFET electrical parameters and the key electrical parameters in the prior art.

[0026] 2. The MOSFET working area is divided according to the change of the gate-source voltage within a preset time period, and then the control signal of the MOSFET electrical parameters in the cut-off area is adjusted. At the same time, the control signal is converted into an electrical signal to drive the MOSFET to work, so that the control signal can be obtained more accurately, thereby improving the accuracy of the MOSFET working area division.

[0027] 3. When the positive voltage in the gate-source voltage is less than the turn-on voltage, the voltage deviation of the MOSFET in the cut-off region is obtained and used as the content of the control signal of the control unit. When the positive voltage in the gate-source voltage is greater than the turn-on voltage, the change of the gate-source voltage is monitored in real time. When the positive voltage is less than or equal to the turn-on voltage, the voltage deviation of the MOSFET in the cut-off region is obtained again and used as the content of the control signal of the control unit, thereby achieving more accurate acquisition of the voltage deviation in the cut-off region of the MOSFET, and then achieving more accurate judgment of the gate-source voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a MOSFET electrical parameter adaptive adjustment system for electric vehicles provided in an embodiment of the present application;

[0029] Figure 2 A three-dimensional coordinate analysis diagram of the electrical adjustment evaluation index provided in the embodiment of the present application;

[0030] Figure 3 A flow chart of a method for adaptively adjusting electrical parameters of a MOSFET for an electric vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] The embodiment of the present application solves the problem of insufficient utilization of the correlation between MOSFET electrical parameters and key electrical parameters in the prior art by providing a MOSFET electrical parameter adaptive adjustment system and method for electric vehicles. The key electrical parameters of the electric vehicle to be adjusted and the MOSFET electrical parameters are acquired in real time within a preset time period through a parameter acquisition module. Then, the electrical adjustment value is acquired according to the actual operating state of the electric vehicle to be adjusted within the preset time period through a parameter adjustment value acquisition module. Then, the electrical adjustment evaluation index is acquired according to the electrical adjustment value through a control execution module. Based on the electrical adjustment evaluation index and the corresponding preset threshold range, it is determined whether to perform dynamic adjustment of the electrical parameters of the MOSFET drive circuit of the electric vehicle to be adjusted. Finally, when performing dynamic adjustment of the electrical parameters, the MOSFET module monitors the gate-source voltage in real time during the dynamic adjustment process and determines whether to adjust the gate-source voltage based on the gate-source voltage until the electrical adjustment value is equal to 0, thereby achieving more precise adjustment of the MOSFET electrical parameters.

[0032] The technical solution in the embodiment of the present application is to solve the problem of insufficient utilization of the correlation between the electrical parameters of the MOSFET and the key electrical parameters. The overall idea is as follows:

[0033] The electrical adjustment value is obtained by obtaining the key electrical parameters of the electric vehicle to be adjusted and the electrical parameters of the MOSFET, and the electrical adjustment evaluation index is obtained based on this. Then, it is determined whether to perform dynamic adjustment of the electrical parameters of the MOSFET drive circuit of the electric vehicle to be adjusted. Finally, based on the gate-source voltage, it is determined whether to adjust the gate-source voltage until the electrical adjustment value is equal to 0, thereby achieving the effect of improving the utilization rate of the correlation between the MOSFET electrical parameters and the key electrical parameters.

[0034] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0035] like Figure 1 As shown, it is a structural schematic diagram of a MOSFET electrical parameter adaptive adjustment system for an electric vehicle provided in an embodiment of the present application. The MOSFET electrical parameter adaptive adjustment system for an electric vehicle provided in an embodiment of the present application includes: a parameter acquisition module, a parameter adjustment value acquisition module, a control execution module and a MOSFET module; wherein the parameter acquisition module is used to acquire the key electrical parameters of the electric vehicle to be adjusted and the MOSFET electrical parameters in real time within a preset time period, the key electrical parameters include on-resistance, actual drive current and actual drive voltage, the MOSFET electrical parameters include on-resistance, drain current and gate voltage, the on-resistance has a positive temperature coefficient, the positive temperature coefficient is used to reflect the influence of ambient temperature on the on-resistance, the MOSFET is a metal oxide semiconductor field effect transistor, and the gate voltage is used to control the drain current; the parameter adjustment value acquisition module is used to acquire the electrical adjustment value according to the actual operating state of the electric vehicle to be adjusted within the preset time period, and the electrical adjustment value includes the resistance adjustment value, current adjustment value and voltage adjustment value, the resistance adjustment value is the absolute value of the difference between the on-resistance and the on-state resistance, the current adjustment value is the absolute value of the difference between the actual drive current and the drain current, and the voltage adjustment value is the absolute value of the difference between the actual drive voltage and the gate voltage; the control execution module is used to obtain an electrical adjustment evaluation index according to the electrical adjustment value, and judge whether to perform dynamic adjustment of electrical parameters on the MOSFET drive circuit of the electric vehicle to be adjusted based on the electrical adjustment evaluation index and the corresponding preset threshold range, the electrical adjustment evaluation index is used to measure the matching degree between the electrical adjustment value and the electrical adjustment value to be adjusted, the dynamic adjustment is used to reduce the deviation between the key electrical parameters and the MOSFET electrical parameters, the electrical adjustment value to be adjusted includes the resistance adjustment value to be adjusted, the current adjustment value to be adjusted and the voltage adjustment value to be adjusted; the MOSFET module is used to monitor the gate-source voltage in the dynamic adjustment process in real time when performing dynamic adjustment of electrical parameters and judge whether to adjust the gate-source voltage based on the gate-source voltage until the electrical adjustment value is equal to 0.

[0036] In this embodiment, once the electrical adjustment evaluation index is obtained, it will be compared with the preset threshold range. If the evaluation index indicates that the deviation between the current electrical adjustment value and the value to be adjusted exceeds the preset threshold range, the control execution module will trigger dynamic adjustment of the electrical parameters of the MOSFET drive circuit. The purpose of this dynamic adjustment is to reduce the deviation between the key electrical parameters and the MOSFET electrical parameters, thereby ensuring the stability and performance of the circuit. The preset threshold range is the range corresponding to the maximum and minimum values ​​of the historical electrical adjustment evaluation indicators in the preset database after summing and averaging. Through the collaborative work of the control execution module and the MOSFET module, not only the precise adjustment and real-time monitoring of the electrical parameters of the electric vehicle MOSFET drive circuit are achieved, but also more precise adjustment of the gate-source voltage is achieved.

[0037] Furthermore, the electrical adjustment value is obtained according to the actual operating state of the electric vehicle to be adjusted within a preset time period, and the following steps are also included before: real-time monitoring of the conduction process of the MOSFET to obtain conduction parameters, combining the obtained conduction parameters with the reference on-state resistance value to obtain a conduction performance score, the MOSFET conducts electricity through working carriers, and the conduction parameters include working carrier concentration and working carrier mobility. The conduction performance score is used to reflect the stability of the conduction performance of the MOSFET during the conduction process, and the conduction performance score is calculated by the following formula:

[0038]

[0039] Where q is the number of the preset time period, q = 1, 2, ..., Q, Q is the total number of preset time periods, e is a natural constant, YIN q represents the conductivity performance score of MOSFET in the qth preset time period, δ represents the ambient temperature influence factor, represents the on-resistance value in the qth preset time period, Indicates the reference on-resistance value, Z1 q It represents the working carrier concentration of MOSFET in the qth preset time period, Z2 q It represents the working carrier mobility of MOSFET in the qth preset time period.

[0040] In this embodiment, in actual application, the MOSFET is placed in a magnetic field, the current of the MOSFET during operation is measured by an ammeter, and the Hall voltage generated is measured by a voltmeter, and the working carrier concentration is obtained and normalized, wherein the Hall voltage represents the potential difference generated in the direction perpendicular to the current and the magnetic field, and the working carrier concentration represents the ratio of the first product (the product of the current and the magnetic field strength) to the second product (the product of the Hall voltage and the charge of the electrons in the magnetic field), and the charge of the electrons is usually 1.602×10 -19 Coulomb; uses pulsed light to excite the working carriers in the semiconductor, and obtains the working carrier mobility (the ratio of the timestamp to the preset time period) by recording the timestamp used by the working carriers from the excitation point to the collection point within a preset time period.

[0041] Specifically, to simplify the analysis, define Where R1 q The change statistics of the on-resistance ratio and the conductivity score of the MOSFET in the qth preset time period are shown in Table 1:

[0042] Table 1 Statistics of changes in conductivity scores

[0043]

[0044] It should be understood that the on-resistance of the MOSFET is measured by a milliohm meter, and the reference on-resistance is expressed by the sum and average of the historical minimum on-resistances in the preset database, that is, the reference on-resistance is the minimum on-resistance value during the MOSFET conduction process. At this time, the current flowing through the MOSFET is the largest, and the corresponding conduction effect is the best. It should be noted that The on-resistance score decreases as the on-resistance increases. When the on-resistance is 1, the current of the MOSFET flows through the conductor without obstacles during operation; the conductivity score increases with the increase of the working carrier concentration and the working carrier mobility: when the working carrier concentration increases, more carriers can participate in conduction, resulting in a decrease in resistance and an improvement in conductivity; when the working carrier mobility increases, the carriers move faster in the electric field, which also results in a decrease in resistance and an improvement in conductivity.

[0045] It should be noted that the working carrier concentration also indirectly affects the value of the working carrier mobility. When the working carrier concentration increases, the average distance between the carriers decreases, resulting in enhanced interaction between them. Coulomb scattering between carriers may become one of the dominant scattering mechanisms. Coulomb scattering is the scattering between carriers due to the Coulomb force (i.e., the interaction force between charges), which reduces the carrier mobility.

[0046] Specifically, the ambient temperature impact factor is an impact factor corresponding to the ambient temperature in a preset database, which represents the numerical value of the impact degree of the ambient temperature on the conductive performance score. When used, the impact factor corresponding to the ambient temperature can be directly obtained from the preset database, and the corresponding relationship can be a pre-set mapping relationship. For example, the ambient temperature corresponding to the impact degree of the MOSFET in the on state and the impact factor corresponding to the ambient temperature in the preset database form a mapping set, and the real-time ambient temperature is input into the mapping set to obtain the corresponding impact factor. The mapping relationship can be one-to-one or many-to-one, wherein the ambient temperature is usually the indoor temperature where the MOSFET is in the on state. The value range of the ambient temperature impact factor in this example is [0,1].

[0047] By considering the effects of on-resistance, ambient temperature, working carrier concentration and working carrier mobility on the conductive performance of MOSFET, and using the mapping relationship in a preset database to obtain the accurate ambient temperature influence factor, it is helpful to more accurately evaluate the conductive performance of MOSFET, thereby improving the accuracy and reliability of obtaining the conductive performance score, and further achieving more precise adjustment of the electrical parameters of MOSFET, solving the problem of insufficient utilization of the correlation between MOSFET electrical parameters and key electrical parameters in the prior art.

[0048] Further, the obtained conductive parameters are combined with the reference on-state resistance value to obtain the conductive performance score, and then the following steps are included: real-time monitoring of the on-time parameters of the MOSFET, combining the monitored on-time parameters with the obtained conductive performance score and the rated drive current and rated drive voltage to obtain the on-state control score, the on-time parameters include the on-time and the off-time, the on-state control score is used to reflect the performance of the MOSFET in the on-state within a preset time period, and the on-state control score is calculated by the following formula:

[0049]

[0050] In the formula, DAO q It represents the conduction state control fraction of MOSFET in the qth preset time period, represents the turn-on time of MOSFET in the qth preset time period, It represents the turn-on delay time of MOSFET in the qth preset time period, It represents the current rise time of MOSFET in the qth preset time period, It represents the voltage drop time of MOSFET in the qth preset time period. represents the off time of MOSFET in the qth preset time period, It represents the turn-off delay time of MOSFET in the qth preset time period. It represents the voltage rise time of MOSFET in the qth preset time period, represents the current falling time of MOSFET in the qth preset time period, T0 represents the preset duration stamp, L0 represents the rated drive current, L q represents the actual driving current of the electric vehicle to be adjusted in the qth preset time period, Y0 represents the rated driving voltage, Y q It represents the actual driving voltage of the electric vehicle to be adjusted in the qth preset time period.

[0051] In this embodiment, the rated drive current is represented by the result of summing and averaging the historical drive currents in the preset database, the rated drive voltage is represented by the result of summing and averaging the historical drive voltages in the preset database, and the actual drive voltage and the actual drive current are measured in real time by a voltmeter and an ammeter; the turn-on delay time is the difference between the time when the MOSFET starts to turn on and the time when it starts to receive the turn-on signal; the current rise time represents the time required for the drain current to rise from an initial value to its final value; the voltage fall time represents the time required for the drain voltage to fall from an initial value to its final value; the turn-off delay time is the difference between the time when the MOSFET starts to turn off and the time when it starts to receive the turn-off signal; the voltage rise time represents the time required for the drain voltage to rise from an initial value (close to zero) to its final value; the current fall time represents the time required for the drain current to fall from an initial value to its final value.

[0052] It is important to understand that L0 ≥ L q And Y0≥Y q , when the actual driving current value and the actual driving voltage value are larger, the corresponding conduction performance is better: in the MOSFET driving circuit of the electric vehicle, if the actual driving current value increases, the gate voltage can reach the required turn-on or turn-off voltage faster, thereby accelerating the switching speed of the MOSFET and improving its conduction performance; when the actual driving voltage value is larger, the on-resistance of the MOSFET is smaller, and the drain current is larger, thereby improving the conduction performance of the MOSFET; the conduction state control score increases with the increase of the conductive performance score, and decreases with the increase of the conduction time parameter: when the conductive performance score increases, the resistance in the corresponding MOSFET driving circuit decreases, the drain current increases, and the conduction performance is better, that is, the performance of the MOSFET in the on state within the preset time period is better; when the on-time parameter increases, the corresponding MOSFET conduction speed is slower, reducing its conduction performance, that is, the performance of the MOSFET in the on state within the preset time period is worse.

[0053] It should be noted that the conductivity performance score also indirectly affects the value of the on-time parameter. Assuming that in the motor control system of an electric vehicle, MOSFET is used as the switching element of the inverter. In order to improve the response speed and efficiency of the system, at this time, if the on-impact score is increased by optimizing the design of the drive circuit (such as increasing the drive voltage and reducing the gate resistance), the gate capacitance charging and discharging efficiency of the MOSFET is improved, which helps to shorten the on-time parameter, improve the performance and control efficiency of the motor control system, and achieve an improvement in the accuracy and reliability of the on-state control score acquisition, thereby achieving more precise adjustment of the MOSFET electrical parameters, and solving the problem of insufficient utilization of the correlation between MOSFET electrical parameters and key electrical parameters in the prior art.

[0054] Further, the on-state control score is obtained, and then the following steps are included: determine whether the on-state control score within a preset time period is equal to the on-state reference control score. If so, continue to monitor the on-state of the MOSFET within the preset time period in real time; otherwise, adjust the on-time parameters of the MOSFET according to the obtained deviation, and the deviation is the difference between the on-state reference control score and the on-state control score; the specific process of adjusting the on-time parameters of the MOSFET is: step 1, determine whether the on-time is greater than the off-time, and if so, obtain a first time difference and reduce the on-time according to the first time difference until The on-time is equal to the off-time, otherwise, execute step 2, where the first time difference is the difference between the on-time and the off-time; step 2, determine whether the on-time is less than the off-time, if so, obtain the second time difference and reduce the off-time according to the second time difference until the off-time is equal to the on-time, otherwise execute step 3, where the second time difference is the difference between the off-time and the on-time; step 3, reduce the duration of the on-time and the off-time until the duration of the on-time and the off-time is equal to the preset duration; step 4, recalculate the on-state control score according to the on-time parameter of the adjusted MOSFET until it is equal to the on-state reference control score.

[0055] In this embodiment, the on-time of the MOSFET is reduced by increasing the on-resistance, and the off-time is reduced by increasing the on-frequency. The on-state reference control score is represented by the result of summing and averaging the historical on-state control scores in a preset database, and the preset duration is represented by the result of summing and averaging the historical on-to-off durations in the preset database. By judging the difference between the on-time and the off-time, the switch on-state of the MOSFET drive circuit can be judged more accurately, thereby improving the on-performance of the MOSFET drive circuit in the electric vehicle and achieving an improvement in the stability of the MOSFET on-state control.

[0056] Furthermore, an electrical adjustment value is obtained according to the actual operating state of the electric vehicle to be adjusted within a preset time period, and then a deviation evaluation index is obtained. The specific acquisition steps are: real-time monitoring of the on-frequency and on-temperature of the MOSFET, and combining the monitored on-frequency and on-temperature with the deviation weight factor, on-frequency weight factor and on-temperature weight factor obtained from a preset database to obtain a deviation evaluation index. The deviation evaluation index is used to quantify the degree of impact on the on-state of the MOSFET within a preset time period.

[0057] Specifically, the deviation evaluation index is calculated by the following formula:

[0058]

[0059] In the formula, CHA q represents the deviation evaluation index of MOSFET in the qth preset time period, α1 represents the deviation weight factor, D q represents the deviation of MOSFET in the qth preset time period, D0 represents the reference deviation, α2 represents the duration weight factor, E q represents the conduction frequency of MOSFET in the qth preset time period, E0 represents the reference conduction frequency, α3 represents the conduction temperature weight factor, F q represents the on-temperature of the MOSFET in the qth preset time period, and F0 represents the reference on-temperature.

[0060] In this embodiment, by connecting the probe of the oscilloscope to the gate and source (or drain) of the MOSFET, the waveform of the gate drive signal can be observed, and the conduction frequency can be obtained by measuring the time interval between two adjacent rising edges (or falling edges) in the waveform; the higher the conduction frequency, the more times the MOSFET needs to be switched within a preset time, which will lead to an increase in switching losses, because each switch is accompanied by energy loss (such as capacitor charging and discharging, resistor heating), which in turn leads to an increase in the degree of influence on the conduction state of the MOSFET within the preset time period (that is, the larger the deviation evaluation index).

[0061] It should be noted that in the calculation formula of the deviation evaluation index, the on-frequency is greater than or equal to the reference on-frequency, the on-temperature is greater than or equal to the reference on-temperature, and the on-temperature of the MOSFET is measured in real time by the temperature sensor on the MOSFET driving circuit. The higher the on-temperature, the poorer the heat dissipation performance of the MOSFET, which in turn leads to an increase in the degree of influence of the MOSFET on-state within the preset time period (i.e., the larger the deviation evaluation index); the reference deviation is represented by the result of summing and averaging the historical deviations in the preset database, the reference on-frequency is represented by the result of summing and averaging the historical on-frequency in the preset database, and the reference on-temperature is represented by the result of summing and averaging the historical on-temperature in the preset database; the deviation evaluation index increases with the increase of the deviation, the on-frequency and the on-temperature. The larger the deviation, the greater the difference between the on-state reference control score and the on-state control score. At this time, the degree of influence of the MOSFET on-state within the preset time period increases (i.e., the larger the deviation evaluation index).

[0062] It should be understood that the deviation weight factor is the weight factor corresponding to the deviation in the preset database, which represents the numerical value of the degree of influence of the deviation on the deviation evaluation index. When used, the weight factor corresponding to the deviation can be directly obtained from the preset database, and the corresponding relationship can be a pre-set mapping relationship. For example, the deviation corresponding to the degree of influence of the conduction control on the MOSFET in the on state and the weight factor corresponding to the deviation in the preset database form a mapping set, and the real-time deviation is input into the mapping set to obtain the corresponding weight factor, wherein the mapping relationship can be one-to-one or many-to-one. The value range of the deviation weight factor in this example is [0,1].

[0063] The conduction frequency weight factor is a weight factor corresponding to the conduction frequency in the preset database, which represents the numerical value of the influence of the conduction frequency on the deviation evaluation index. When used, the weight factor corresponding to the conduction frequency can be directly obtained from the preset database, and the corresponding relationship can be a preset mapping relationship. For example, the conduction frequency corresponding to the degree of influence of the conduction frequency on the MOSFET in the conduction state and the weight factor corresponding to the conduction frequency in the preset database form a mapping set, and the real-time conduction frequency is input into the mapping set to obtain the corresponding weight factor, wherein the mapping relationship can be one-to-one or many-to-one. In this example, the value range of the conduction frequency weight factor is [0,1].

[0064] The on-temperature weight factor is a weight factor corresponding to the on-temperature in the preset database, which indicates the numerical value of the influence of the on-temperature on the deviation evaluation index. When used, the weight factor corresponding to the on-temperature can be directly obtained from the preset database, and the corresponding relationship can be a pre-set mapping relationship. For example, the on-temperature corresponding to the degree of influence of the on-temperature on the MOSFET in the on state and the weight factor corresponding to the on-temperature in the preset database form a mapping set, and the real-time on-temperature is input into the mapping set to obtain the corresponding weight factor, wherein the mapping relationship can be one-to-one or many-to-one. In this example, the value range of the on-temperature weight factor is [0,1].

[0065] By comprehensively considering the influence of deviation, conduction frequency and conduction temperature on the value of deviation evaluation index, the deviation evaluation index is made closer to the actual operation of electric vehicles, which helps to improve the efficiency of real-time monitoring and management of MOSFET conduction performance, and achieves improved accuracy and reliability in obtaining electrical adjustment evaluation indicators, thereby achieving more precise adjustment of MOSFET electrical parameters, and solving the problem of insufficient utilization of the correlation between MOSFET electrical parameters and key electrical parameters in the prior art.

[0066] Furthermore, the electrical adjustment evaluation index is calculated by the following formula:

[0067]

[0068] Where TIAO q represents the electrical adjustment evaluation index of MOSFET in the qth preset time period, β represents the deviation evaluation index correction factor, and J q represents the resistance adjustment value of MOSFET in the qth preset time period, J0 represents the resistance adjustment value to be adjusted, K q represents the current adjustment value of MOSFET in the qth preset time period, K0 represents the current adjustment value to be adjusted, H q It represents the voltage adjustment value of MOSFET in the qth preset time period, and H0 represents the voltage adjustment value to be adjusted.

[0069] In this embodiment, the electrical adjustment evaluation index increases with the increase of the resistance adjustment value, the current adjustment value and the voltage adjustment value. In order to simplify the analysis, C1 is defined as q =β*CHA q , Where C1 q C2 represents the deviation evaluation index coefficient of MOSFET in the qth preset time period. q It represents the electrical adjustment value coefficient of MOSFET in the qth preset time period. The simplified calculation formula of the electrical adjustment evaluation index is: like Figure 2 As shown, it is a three-dimensional coordinate analysis diagram of the electrical adjustment evaluation index provided in the embodiment of the present application. It can be seen from the figure that the electrical adjustment evaluation index decreases with the increase of the deviation evaluation index coefficient, and increases with the increase of the electrical adjustment value coefficient.

[0070] The resistance adjustment value to be adjusted is represented by the result of summing and averaging the historical adjustment resistance values ​​in the preset database, the current adjustment value to be adjusted is represented by the result of summing and averaging the historical adjustment current values ​​in the preset database, and the voltage adjustment value to be adjusted is represented by the result of summing and averaging the historical adjustment voltage values ​​in the preset database. When C1 q = 0 (indicating that the degree of influence on the MOSFET conduction state during the preset time period is 0) and C2 q =0, the corresponding electrical adjustment evaluation value is 2. At this time, the electrical adjustment value matches the electrical adjustment value to be adjusted to the highest degree. q =0: Take the ratio of the resistance adjustment value to the resistance adjustment value to be adjusted as an example. When the resistance adjustment value is equal to the resistance value to be adjusted, it means that the resistance adjustment is completely accurate and there is no deviation. Similarly, when the current adjustment value is equal to the current value to be adjusted and the voltage adjustment value is equal to the voltage value to be adjusted, it means that the current and voltage adjustments are completely accurate and there is no deviation. At this time, the corresponding C2 q =0.

[0071] It should be understood that the deviation assessment index correction factor is a correction factor corresponding to the deviation assessment index in the preset database, which represents the value of the correction of the degree of influence of the deviation assessment index on the electrical adjustment assessment index. When used, the correction factor corresponding to the deviation assessment index can be directly obtained from the preset database, and the corresponding relationship can be a pre-set mapping relationship. For example, the deviation assessment index corresponding to the degree of influence of the MOSFET in the on state and the correction factor corresponding to the deviation assessment index in the preset database form a mapping set, and the real-time deviation assessment index is input into the mapping set to obtain the corresponding correction factor, wherein the mapping relationship can be one-to-one or many-to-one. The value range of the deviation assessment index correction factor in this example is [0,1].

[0072] By correcting the electrical adjustment evaluation index by considering the deviation evaluation index correction factor, it is helpful to more accurately reflect the actual working state of the MOSFET, improve the precise control of the MOSFET working state, and achieve improved accuracy and reliability in obtaining the electrical adjustment evaluation index, thereby achieving more precise adjustment of the MOSFET electrical parameters, and solving the problem of insufficient utilization of the correlation between the MOSFET electrical parameters and the key electrical parameters in the prior art.

[0073] Furthermore, the specific process of dynamically adjusting the electrical parameters of the MOSFET drive circuit of the electric vehicle to be adjusted is: real-time monitoring of the numerical changes of the electrical adjustment evaluation index to obtain the positive deviation and negative deviation of the electrical adjustment evaluation index, the positive deviation is a deviation value less than a preset threshold range, and the negative deviation is a deviation value greater than the preset threshold range; sending an adjustment instruction to the PWM controller to adjust the MOSFET electrical parameters and recalculate the electrical adjustment evaluation index until the electrical adjustment evaluation index is within the corresponding preset threshold range, the adjustment instruction is the size of the positive deviation and the negative deviation, and the PWM controller is the actuator in the MOSFET drive circuit of the electric vehicle to be adjusted.

[0074] In this embodiment, a pulse width modulation (PWM controller) is used as an executive element to receive control instructions from a MOSFET drive circuit (such as changing the duty cycle of a PWM signal). If it is a positive deviation, the duty cycle of the PWM signal is increased until it is equal to a preset duty cycle, and the gate voltage is increased. If it is a negative deviation, the duty cycle of the PWM signal is reduced until it is equal to the preset duty cycle, and the gate voltage is reduced. The preset duty cycle is represented by the result of summing and averaging the historical duty cycles in a preset database. The duty cycle of the PWM signal represents the proportion of the high level time to the preset time period, which determines the average on-time of the MOSFET during the conduction process, thereby reducing the deviation between the electrical adjustment evaluation index and the corresponding preset threshold range, and realizing more precise adjustment of the electrical parameters of the MOSFET of the electric vehicle.

[0075] Furthermore, the MOSFET module includes a region division unit, a control unit and a driving unit; the region division unit is used to divide the MOSFET working area according to the change of the gate-source voltage within a preset time period, and the MOSFET working area includes a cut-off area and a saturation area; the control unit is used to adjust the control signal of the electrical parameters of the MOSFET in the cut-off area; the driving unit is used to connect the control unit with the MOSFET driving circuit and receive the control signal sent by the control unit, and at the same time convert the control signal into an electrical signal for driving the MOSFET to work, and the electrical signal directly acts on the gate of the MOSFET to change the conduction state.

[0076] In this embodiment, when the positive voltage of the MOSFET is lower than the turn-on voltage, the MOSFET is in the cut-off state. At this time, almost no current passes between the source and the drain. In this area, the control unit can adjust the electrical parameters of the MOSFET by sending a control signal (although in the cut-off region, the main adjustment is to make the MOSFET exit the cut-off state); when the positive voltage of the MOSFET is higher than the turn-on voltage, the MOSFET enters the saturation region. In this region, the drain current of the MOSFET is mainly controlled by the positive voltage, and the influence of the start-up voltage is negligible. This is a common working area when the MOSFET is used as a switch or amplifier, in which the control signal indicates that the MOSFET changes from the cut-off state to the on state (enters the saturation region); through the coordinated work of the control unit and the drive unit, the precise division of the MOSFET working area can be achieved, thereby achieving the improvement of the real-time and accuracy of the gate-source voltage control.

[0077] Furthermore, the specific steps of dividing the MOSFET working area include: E1, when the positive voltage in the gate-source voltage is less than the turn-on voltage, it indicates that the MOSFET is working in the cut-off area, and the voltage deviation of the MOSFET in the cut-off area is obtained and used as the content of the control signal of the control unit, and the voltage deviation is the difference between the turn-on voltage and the positive voltage; E2, when the positive voltage in the gate-source voltage is greater than the turn-on voltage, it indicates that the MOSFET is working in the saturation area, and the change of the gate-source voltage is monitored in real time, and when the positive voltage is less than or equal to the turn-on voltage, return to E1.

[0078] In this embodiment, the working state of the MOSFET is judged by the ratio between the positive voltage and the turn-on voltage, so that the MOSFET can be quickly switched between the cut-off region and the saturation region, thereby improving the control efficiency and reliability of the gate-source voltage and achieving improved control stability and efficiency of the MOSFET on-state.

[0079] like Figure 3As shown, it is a flow chart of the MOSFET electrical parameter adaptive adjustment method for electric vehicles provided in an embodiment of the present application. The MOSFET electrical parameter adaptive adjustment method for electric vehicles provided in an embodiment of the present application comprises the following steps: S1, real-time acquisition of key electrical parameters of the electric vehicle to be adjusted and MOSFET electrical parameters within a preset time period, the key electrical parameters comprising on-resistance, actual drive current and actual drive voltage, MOSFET electrical parameters comprising on-resistance, drain current and gate voltage, on-resistance having a positive temperature coefficient, the positive temperature coefficient being used to reflect the degree of influence of ambient temperature on on-resistance, MOSFET being a metal oxide semiconductor field effect transistor, the gate voltage being used to control drain current; S2, acquiring electrical adjustment values ​​according to the actual operating state of the electric vehicle to be adjusted within the preset time period, the electrical adjustment values ​​comprising resistance adjustment values, current adjustment values ​​and voltage adjustment values, the resistance adjustment value being the on-resistance and The absolute value of the difference between the on-state resistance, the current adjustment value is the absolute value of the difference between the actual driving current and the drain current, and the voltage adjustment value is the absolute value of the difference between the actual driving voltage and the gate voltage; S3, obtaining an electrical adjustment evaluation index according to the electrical adjustment value, and judging whether to perform dynamic adjustment of electrical parameters on the MOSFET drive circuit of the electric vehicle to be adjusted based on the electrical adjustment evaluation index and the corresponding preset threshold range, the electrical adjustment evaluation index is used to measure the degree of matching between the electrical adjustment value and the electrical adjustment value to be adjusted, and the dynamic adjustment is used to reduce the deviation between the key electrical parameters and the electrical parameters of the MOSFET, and the electrical adjustment value to be adjusted includes the resistance adjustment value to be adjusted, the current adjustment value to be adjusted, and the voltage adjustment value to be adjusted; S4, when performing dynamic adjustment of electrical parameters, real-time monitoring of the gate-source voltage in the dynamic adjustment process and judging whether to adjust the gate-source voltage based on the gate-source voltage until the electrical adjustment value is equal to 0, the gate-source voltage includes a positive voltage and a turn-on voltage.

[0080] In this embodiment, during the dynamic adjustment process, it is necessary to monitor the gate-source voltage in real time (note that it should be the gate-source voltage rather than the gate voltage, because the gate-source voltage is the key to controlling the conduction state of the MOSFET). By real-time monitoring and adjusting the key electrical parameters and the MOSFET electrical parameters, the drive circuit of the electric vehicle can be more accurately controlled, thereby improving the utilization rate of the correlation between the MOSFET electrical parameters and the key electrical parameters.

[0081] To summarize, the embodiment of the present application obtains the key electrical parameters of the electric vehicle to be adjusted and the electrical parameters of the MOSFET to obtain the electrical adjustment value, obtains the electrical adjustment evaluation index based on this, and then determines whether to perform dynamic adjustment of the electrical parameters of the MOSFET drive circuit of the electric vehicle to be adjusted. Finally, based on the gate-source voltage, it determines whether to adjust the gate-source voltage until the electrical adjustment value is equal to 0, thereby improving the accuracy of dynamic adjustment, and further achieving more precise adjustment of the MOSFET electrical parameters, effectively solving the problem of insufficient utilization of the correlation between MOSFET electrical parameters and key electrical parameters in the prior art.

[0082] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0083] The present invention is described with reference to flowcharts and / or block diagrams of systems, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0084] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0085] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0086] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0087] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A MOSFET electrical parameter adaptive adjustment system for electric vehicles, characterized in that: include: Parameter acquisition module, parameter adjustment value acquisition module, control execution module and MOSFET module; The parameter acquisition module is used to acquire the key electrical parameters of the electric vehicle to be adjusted and the electrical parameters of the MOSFET in real time within a preset time period, wherein the key electrical parameters include on-resistance, actual drive current and actual drive voltage, and the electrical parameters of the MOSFET include on-resistance, drain current and gate voltage; The parameter adjustment value acquisition module is used to acquire the electrical adjustment value according to the actual operating state of the electric vehicle to be adjusted within a preset time period; The control execution module is used to obtain an electrical adjustment evaluation index according to the electrical adjustment value, and determine whether to perform dynamic adjustment of electrical parameters on the MOSFET drive circuit of the electric vehicle to be adjusted based on the electrical adjustment evaluation index and the corresponding preset threshold range, wherein the electrical adjustment evaluation index is used to measure the matching degree between the electrical adjustment value and the electrical adjustment value to be adjusted; The MOSFET module is used to monitor the gate-source voltage in real time during the dynamic adjustment of electrical parameters and determine whether to adjust the gate-source voltage until the electrical adjustment value is equal to 0 based on the gate-source voltage.

2. The MOSFET electrical parameter adaptive adjustment system for electric vehicles according to claim 1, characterized in that: The step of obtaining the electrical adjustment value according to the actual operating state of the electric vehicle to be adjusted within a preset time period also includes the following steps: The conduction process of the MOSFET is monitored in real time to obtain conduction parameters, and the obtained conduction parameters are combined with the reference on-resistance value to obtain a conduction performance score, which is used to reflect the stability of the conduction performance of the MOSFET during the conduction process. The conduction performance score is calculated by the following formula: Where q is the number of the preset time period, q = 1, 2, ..., Q, Q is the total number of preset time periods, e is a natural constant, YIN q represents the conductivity performance score of MOSFET in the qth preset time period, δ represents the ambient temperature influence factor, represents the on-resistance value in the qth preset time period, Indicates the reference on-resistance value, Z1 q It represents the working carrier concentration of MOSFET in the qth preset time period, Z2 q It represents the working carrier mobility of MOSFET in the qth preset time period.

3. The MOSFET electrical parameter adaptive adjustment system for electric vehicles as claimed in claim 2, characterized in that: The step of combining the obtained conductive parameters with the reference on-resistance value to obtain a conductive performance score further includes the following steps: Monitor the on-time parameters of the MOSFET in real time, and combine the monitored on-time parameters with the conductivity score obtained, the rated drive current, and the rated drive voltage to obtain the on-state control score. The on-time parameters include the on-time and off-time. The on-state control score is used to reflect the performance of the MOSFET in the on-state within a preset time period. The on-state control score is calculated by the following formula: In the formula, DAO q It represents the conduction state control fraction of MOSFET in the qth preset time period, represents the turn-on time of MOSFET in the qth preset time period, It represents the turn-on delay time of MOSFET in the qth preset time period, It represents the current rise time of MOSFET in the qth preset time period, It represents the voltage drop time of MOSFET in the qth preset time period. represents the off time of MOSFET in the qth preset time period, It represents the turn-off delay time of MOSFET in the qth preset time period. It represents the voltage rise time of MOSFET in the qth preset time period, represents the current falling time of MOSFET in the qth preset time period, T0 represents the preset duration stamp, L0 represents the rated drive current, L q represents the actual driving current of the electric vehicle to be adjusted in the qth preset time period, Y0 represents the rated driving voltage, Y q It represents the actual driving voltage of the electric vehicle to be adjusted in the qth preset time period.

4. The MOSFET electrical parameter adaptive adjustment system for electric vehicles as claimed in claim 3, characterized in that: The step of obtaining the conduction state control score further includes the following steps: Determine whether the on-state control score within the preset time period is equal to the on-state reference control score. If so, continue to monitor the on-state of the MOSFET within the preset time period in real time. Otherwise, adjust the on-time parameter of the MOSFET according to the obtained deviation, where the deviation is the difference between the on-state reference control score and the on-state control score. The specific process of adjusting the on-time parameters of the MOSFET is as follows: Step 1, determine whether the on-time is greater than the off-time, if so, obtain a first time difference and reduce the on-time according to the first time difference until the on-time is equal to the off-time, otherwise execute step 2, the first time difference is the difference between the on-time and the off-time; Step 2, determine whether the on-time is less than the off-time, if so, obtain a second time difference and reduce the off-time according to the second time difference until the off-time is equal to the on-time, otherwise execute step 3, the second time difference is the difference between the off-time and the on-time; Step 3, reducing the duration of the on-time and the off-time until the duration of the on-time and the off-time is equal to the preset duration; Step 4: recalculate the on-state control fraction according to the adjusted on-time parameter of the MOSFET until it is equal to the on-state reference control fraction.

5. The MOSFET electrical parameter adaptive adjustment system for electric vehicles as claimed in claim 4, characterized in that: The electrical adjustment value is obtained according to the actual operating state of the electric vehicle to be adjusted within a preset time period, and then the deviation evaluation index is obtained. The specific acquisition steps are: The on-frequency and on-temperature of the MOSFET are monitored in real time, and the monitored on-frequency and on-temperature are combined with the deviation weight factor, the on-frequency weight factor and the on-temperature weight factor obtained from a preset database to obtain a deviation evaluation index, which is used to quantify the degree of impact on the on-state of the MOSFET within a preset time period.

6. The MOSFET electrical parameter adaptive adjustment system for electric vehicles as claimed in claim 5, characterized in that: The electrical adjustment evaluation index is calculated by the following formula: Where TIAO q represents the electrical adjustment evaluation index of MOSFET in the qth preset time period, β represents the deviation evaluation index correction factor, and J q represents the resistance adjustment value of MOSFET in the qth preset time period, J0 represents the resistance adjustment value to be adjusted, K q represents the current adjustment value of MOSFET in the qth preset time period, K0 represents the current adjustment value to be adjusted, H q It represents the voltage adjustment value of MOSFET in the qth preset time period, and H0 represents the voltage adjustment value to be adjusted.

7. The MOSFET electrical parameter adaptive adjustment system for electric vehicles according to claim 1, characterized in that: The specific process of dynamically adjusting the electrical parameters of the MOSFET drive circuit of the electric vehicle to be adjusted is as follows: Obtaining a positive deviation and a negative deviation of an electrical adjustment evaluation index, wherein the positive deviation is a deviation value less than a preset threshold range, and the negative deviation is a deviation value greater than a preset threshold range; The adjustment instruction is sent to the PWM controller to adjust the MOSFET electrical parameters and recalculate the electrical adjustment evaluation index until the electrical adjustment evaluation index is within the corresponding preset threshold range.

8. The MOSFET electrical parameter adaptive adjustment system for electric vehicles according to claim 1, characterized in that: The MOSFET module includes a region dividing unit, a control unit and a driving unit; The region division unit is used to divide the MOSFET working region according to the change of the gate-source voltage within a preset time period, and the MOSFET working region includes a cut-off region and a saturation region; The control unit is used to adjust the control signal of the electrical parameters of the MOSFET in the cut-off region; The driving unit is used to connect the control unit and the MOSFET driving circuit and receive the control signal sent by the control unit, and convert the control signal into an electrical signal for driving the MOSFET to work. The electrical signal directly acts on the gate of the MOSFET to change the conduction state.

9. The MOSFET electrical parameter adaptive adjustment system for electric vehicles as claimed in claim 8, characterized in that: The specific steps of dividing the MOSFET working area include: E1, when the positive voltage in the gate-source voltage is less than the turn-on voltage, the voltage deviation of the MOSFET in the cut-off region is obtained and used as the content of the control signal of the control unit, and the voltage deviation is the difference between the turn-on voltage and the positive voltage; E2, when the positive voltage in the gate-source voltage is greater than the turn-on voltage, monitor the change of the gate-source voltage in real time, and return to E1 when the positive voltage is less than or equal to the turn-on voltage.

10. A method for adaptively adjusting electrical parameters of MOSFET for electric vehicles, characterized in that: The following steps are involved: S1, acquiring key electrical parameters of the electric vehicle to be adjusted and electrical parameters of the MOSFET in real time within a preset time period, wherein the key electrical parameters include on-resistance, actual driving current and actual driving voltage, and the electrical parameters of the MOSFET include on-resistance, drain current and gate voltage; S2, obtaining an electrical adjustment value according to the actual operating state of the electric vehicle to be adjusted within a preset time period; S3, obtaining an electrical adjustment evaluation index according to the electrical adjustment value, and judging whether to perform dynamic adjustment of electrical parameters on the MOSFET drive circuit of the electric vehicle to be adjusted based on the electrical adjustment evaluation index and the corresponding preset threshold range, wherein the electrical adjustment evaluation index is used to measure the matching degree between the electrical adjustment value and the electrical adjustment value to be adjusted; S4, when performing dynamic adjustment of electrical parameters, real-time monitoring of the gate-source voltage during the dynamic adjustment process and judging whether to adjust the gate-source voltage until the electrical adjustment value is equal to 0 based on the gate-source voltage.

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