Transient detection circuit of power device and power device driving device

Abstract

The utility model discloses a transient detection circuit of a power device and a power device driving device, and relates to the technical field of driving control, and the transient detection circuit of the power device comprises a digital signal processing module which is used for generating a pulse modulation signal of each power device in a power circuit according to a received power demand of the power circuit; and the state detection module is connected with the digital signal processing module and is used for detecting transient moments corresponding to a plurality of transient regions of the corresponding power device in the switching process according to the pulse modulation signal. According to the invention, the pulse modulation signal is not interfered by hardware, and the ideal switching state of the power device can be directly reflected, so that the transient moment of the corresponding power device determined according to the pulse modulation signal is more accurate, and the technical problem of low transient detection accuracy of the power device is solved.

Description

Technical Field

[0001] This application relates to the technical field of drive control, and particularly to a transient detection circuit for power devices and a power device drive device. Background Art

[0002] In related technologies, power devices (such as SiC MOSFETs) are mainly driven in an active gate drive (AGD) manner. In the AGD scheme, the drain current of the power device can be collected, and the transient moment corresponding to the transient region during the switching process of the power device can be determined according to the drain current. The drive signal of the power device can be adjusted in different transient regions to optimize the switching trajectory of the power device.

[0003] However, due to the hardware interference in the collected drain current, the detected instantaneous state of the power device is inaccurate. Summary of the Utility Model

[0004] The main purpose of this application is to propose a transient detection circuit for power devices and a power device drive device, aiming to solve the technical problem of low accuracy in transient detection of power devices.

[0005] To achieve the above object, the transient detection circuit for power devices proposed in this application includes:

[0006] A digital signal processing module, configured to generate pulse modulation signals for each power device in the power circuit according to the received power demand of the power circuit;

[0007] A state detection module, connected to the digital signal processing module, configured to detect the transient moments corresponding to multiple transient regions during the switching process of the corresponding power device according to the pulse modulation signals.

[0008] In one embodiment,

[0009] The state detection module is further configured to generate respective drive control signals according to each transient moment;

[0010] The transient detection circuit for power devices further includes:

[0011] A drive module, respectively connected to the state detection module and the power circuit, configured to generate respective drive signals according to each drive control signal to drive the switching of the power device corresponding to the pulse modulation signal.

[0012] In one embodiment,

[0013] The state detection module is further configured to generate multiple power control signals according to the jump moment of the pulse modulation signal and each transient moment;

[0014] The transient detection circuit of the power device further includes:

[0015] A push-pull power supply module, connected to the status detection module, for generating respective corresponding driving voltages according to each power control signal;

[0016] A driving module, also connected to the push-pull power supply module, for generating respective corresponding driving signals according to each driving voltage and the corresponding driving control signal.

[0017] In one embodiment, the transient detection circuit of the power device further includes:

[0018] A level conversion module, connected to the status detection module, for performing level conversion on each driving control signal to obtain a target driving control signal;

[0019] A driving module, connected to the level conversion module, for generating respective corresponding driving signals according to each target driving control signal.

[0020] In one embodiment, the transient detection circuit of the power device further includes:

[0021] A power management module, respectively connected to the power supply and the push-pull power supply module, for converting the output voltage of the power supply into a supply voltage to supply power to the push-pull power supply module.

[0022] In one embodiment, the transient detection circuit of the power device further includes:

[0023] A voltage detection module, connected to the power circuit, for detecting the working voltage of the power device and outputting a voltage detection signal;

[0024] A status detection module, also connected to the voltage detection module, for detecting multiple transient moments of the corresponding power device according to the pulse modulation signal and the voltage detection signal.

[0025] In one embodiment, the transient detection circuit of the power device further includes:

[0026] A temperature detection module, for detecting the working temperature of the power device and outputting a temperature detection signal;

[0027] A status detection module, also connected to the temperature detection module, for detecting multiple transient moments of the corresponding power device according to the pulse modulation signal, the voltage detection signal and the temperature detection signal.

[0028] The present application also proposes a power device driving device, and the power device driving device includes:

[0029] The transient detection circuit of the power device as described above.

[0030] One or more technical solutions proposed by the present application have at least the following technical effects:

[0031] In the technical solution of the present application, the digital signal processing module determines the pulse modulation signals of each power device in the power circuit according to the power demand of the power circuit, and the state detection module detects the transient moments corresponding to the respective power devices in different transient regions according to each pulse modulation signal. Compared with determining the transient moments corresponding to the power devices in different transient regions according to the drain current of the power device, the pulse modulation signal is not affected by hardware interference and can directly reflect the ideal switching state of the power device, so that the transient moments of the corresponding power devices determined according to the pulse modulation signal are more accurate, and the accuracy of transient detection of the power device is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0033] Figure 1 It is a schematic structural diagram of the first embodiment of the transient detection circuit of the power device provided by the present application;

[0034] Figure 2 It is a switching timing diagram of the power device;

[0035] Figure 3 It is a schematic structural diagram of the second embodiment of the transient detection circuit of the power device provided by the present application;

[0036] Figure 4 It is a timing diagram of an exemplary transient moment and a pulse modulation signal;

[0037] Figure 5 It is a schematic flowchart of the first embodiment of the transient detection method of the power device provided by the present application.

[0038] The realization, functional features and advantages of the purpose of the present application will be further described in conjunction with the embodiments with reference to the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present application belong to the scope of protection of the present application.

[0040] It should be noted that in this application, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, such that a device or system including a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such device or system. Without further limitation, an element defined by the statement "including..." does not exclude the presence of additional identical elements in the device or system including that element.

[0041] In this application, unless otherwise clearly specified and defined, terms such as "connect" and "fix" should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] In this application, where there are descriptions involving "first", "second", etc., such descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" can expressly or implicitly include at least one such feature.

[0043] In this application, the use of suffixes such as "module", "component" or "unit" for representing elements is only for the convenience of the description of this application and has no specific meaning in itself. Therefore, "module", "component" or "unit" can be used interchangeably. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances. Additionally, the technical solutions of each embodiment can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0044] SiC MOSFET (Silicon Carbide Metal-Oxide-Semiconductor Field-Effect Transistor) has the advantages of strong high-temperature stability, low loss, fast switching speed, and is suitable for high-frequency applications, thus gradually standing out in the development of power electronics technology. However, SiC MOSFET has relatively high overshoot current, overshoot voltage, and accompanying oscillation problems during the switching transient process. Therefore, a suitable driving scheme is needed to improve the driving problems of SiC MOSFET. The SiC MOSFET driving scheme includes the conventional gate driver (CGD) and the active gate driver (AGD, Active Gate Driver). In related technologies, under the CGD scheme, by additionally adding a transient positioning circuit and a logic judgment circuit, the driving mode of AGD can be obtained, that is, the AGD scheme needs to implement three major functions: the transient positioning function, the logic judgment function, and the driving power amplification function of SiC MOSFET.

[0045] The transient positioning function is mainly to locate the transient moment corresponding to the actual instantaneous action state of SiC MOSFET during the turn-on or turn-off process. Among them, the transient positioning can be achieved in the following ways:

[0046] (1) Based on the relevant changes of the gate loop Vgs during the turn-on and turn-off processes of SiC MOSFET, the actual change of the current Ids is determined, and then the actual switching state is located. However, due to the anti-interference ability problem of this scheme, it has the defects of narrow detection bandwidth and easy misjudgment, and it is difficult to be applied industrially.

[0047] (2) The power loop positioning method that uses a shunt resistor to sample the drain current. Although it has high detection accuracy and good dynamic response for the turn-on and turn-off states of SiC MOSFET, the loss caused by the shunt resistor not only reduces the system efficiency but also increases the system cost, and it is difficult to be applied to new energy electric drive products with high power and large current.

[0048] (3) The drain current sampling scheme that uses a high-bandwidth current mutual inductance coil has high cost and large integration difficulty, which also makes it basically impossible to be industrialized.

[0049] (4) The scheme based on a high-speed ADC chip and peripheral circuits to directly read the data of the current transformer needs to cooperate with the power loop positioning and current detection schemes to achieve its function. However, it has problems such as a large number of devices, high material costs, and reduced system reliability, and it is difficult to be applied to the industrial design of products.

[0050] The function of the logic judgment module is to combine with the state of the PWM signal after receiving the trigger signal of transient positioning, and give the input of the power amplifier circuit adjustment operation according to the logic analysis results of the on-state and off-state. The logic judgment module is mainly divided into building a logic circuit with discrete devices and implementing it with a programmable logic device FPGA or CPLD.

[0051] In addition, the logic judgment function can be realized by the combined design of a comparator and a NAND gate, providing a principle reference for the logic design of integrated circuits. However, for the logic circuit built with discrete devices, the matching and adjustment adaptability of the output of its logic judgment function is poor, which is contrary to the design goals of the new energy vehicle industry to pursue product miniaturization, lightweight and platformization.

[0052] To solve the above technical problems, this application proposes a transient detection circuit for power devices and a power device drive device.

[0053] Please refer to Figure 1 , this application embodiment provides a transient detection circuit for power devices, and the transient detection circuit for power devices may include:

[0054] A digital signal processing module, configured to generate pulse modulation signals for each power device in the power circuit according to the received power demand of the power circuit;

[0055] A state detection module, connected to the digital signal processing module, configured to detect the transient moments corresponding to multiple transient regions of the corresponding power device during the switching process according to the pulse modulation signal.

[0056] It should be noted that the power circuit may be a single-phase power circuit or a multi-phase power circuit. Preferably, the power circuit is a three-phase power circuit of a new energy vehicle control system. A single-phase power circuit may include a series-connected upper-bridge power device and a lower-bridge power device, and the power device is a SiC MOSFET. In actual use, the power demand of the power circuit can be determined according to the control requirements of the new energy vehicle control system and sent to the digital signal processing module. The digital signal processing module may include a DSP (Digital Signal Processing) chip, and the DSP chip can generate the theoretically pulse modulation (PWM, Pulse Width Modulation) signals for each power device in the power circuit according to the power demand of the power circuit.

[0057] The level states between the pulse modulation signals of the upper-bridge power devices and those of the lower-bridge power devices in each-phase power circuit are interlocked. Therefore, when the state detection module receives each pulse modulation signal, it can achieve redundant verification of the dead-time and level-state interlock of the SiCMOSFET gate drive PWM, and combined with the characteristics of the switching process of the SiC MOSFET, locate the transient moments of each power device.

[0058] For example, for the upper-bridge power device and the lower-bridge power device of a phase power circuit, the state detection module can determine the power device that works first according to the working sequence, so as to determine the jump moment of the pulse modulation signal of the power device that works first. Then, according to the level-state interlock characteristic, determine the dead-time, and thus, combined with the jump moment of the pulse modulation signal of the power device that works first, determine the jump moment of the pulse modulation signal of the power device that works later. Similarly, according to the jump moments of the pulse modulation signals of the determined power devices, combined with the working sequence between this power device and other power devices in other-phase power circuits, the jump moments of other pulse modulation signals of other power devices can be determined.

[0059] Among them, the state detection module can be implemented by a logic circuit built with an FPGA (Field Programmable Gate Array, programmable array logic), a CPLD (Complex Programmable Logic Device, complex programmable logic device), or discrete devices.

[0060] It can be understood that if the state detection module is implemented by an FPGA or a CPLD, the functions of locating the transient moments of the power devices according to the pulse modulation signals are integrated in the FPGA and the CPLD; if the state detection module is implemented by a logic circuit built with discrete devices, the discrete devices can include a combination of a comparator and a NAND gate, so that the logic circuit can implement the function of judging the transient moments of the power devices according to the pulse modulation signals.

[0061] As Figure 2 shown, during the switching process of the power device, Region I (t 0 -t 1 ) and Region V (t 5 -t 6 ) represent the turn-on delay and the turn-off delay. The lengths of Region I and Region V directly affect the switching speed of the power device and the setting of the dead-time. Therefore, the shorter these two regions of time are, the better. Region III (t 2 -t 3 ) and Region VII (t 7 -t 8 ) are respectively the current overshoot region during the turn-on process of the SiC MOSFET and the voltage overshoot region during the turn-off process. Region IV (t3 -t 4 ) and Region VIII (t 7 -t 8 ) are the current oscillation region and voltage oscillation region of the SiC MOSFET. Region II (t 1 -t 2 ) and Region VI (t 6 -t 7 ) are respectively the linear rising region of the current and the linear rising region of the voltage of the SiC MOSFET, and are the key control regions for decoupling the switching time, switching loss, and current and voltage overshoot and oscillation. The eight regions from I to VIII are the transient regions corresponding to the SiC MOSFET at different times. During the driving process of the SiC MOSFET, to optimize the switching trajectory of the SiC MOSFET, it is necessary to accurately locate the transient moment at the start of each transient region.

[0062] In addition, it can be understood that, given the selection of the power device, during the switching process of the power device, the duration of each transient region is related to the selection of the power device, that is, the interval duration between the transient moments corresponding to each transient region can be determined according to the structure and material of the power device, etc. Preferably, the state detection module can locate t 0 or t 5 and then, according to each interval duration, sequentially locate t 1 -t 4 or t 6 -t 8 . At this time, the state detection module can be implemented by a logic circuit built with FPGA, CPLD or discrete devices; or the state detection module can also, after locating t 0 or t 5 according to the pulse modulation signal, calculate t 1 -t 4 or t 6 -t 8 by combining the mathematical model of the power device. At this time, the state detection module can be implemented by FPGA or CPLD.

[0063] Therefore, in this embodiment, implementing the state detection module by FPGA or CPLD is more conducive to the miniaturization and lightweight of new energy vehicle control products compared with implementing it by a logic circuit built with discrete devices.

[0064] In a feasible implementation manner, the state detection module is further configured to generate respective drive control signals according to each transient moment;

[0065] As Figure 3 shown, the transient detection circuit of the power device may further include:

[0066] The driving module, which is respectively connected to the state detection module and the power circuit, is used to generate respective driving signals according to each driving control signal, and drive the switching of the power device corresponding to the pulse modulation signal.

[0067] It should be noted that during the switching process of the power device, different gate driving voltages can be used to drive the power device in different transient regions to optimize the switching trajectory of the power device. Therefore, when the state detection module locates each transient moment of a pulse modulation signal, corresponding driving control signals can be generated to control the driving module to output driving signals with different voltages to determine the switching of the power device corresponding to the pulse modulation signal. Among them, the driving module includes a driving chip. The driving chip can output driving signals with different voltages to the gate of the power device when receiving the driving control signal.

[0068] It can be understood that the driving control signal is actually the adjusted pulse modulation signal obtained after adjusting the pulse modulation signal according to each transient moment.

[0069] In a feasible implementation manner, the state detection module is further used to generate multiple power control signals according to the jump moment and each transient moment of the pulse modulation signal;

[0070] Such as Figure 3 shown, the transient detection circuit of the power device may further include:

[0071] The push-pull power supply module, which is connected to the state detection module, is used to generate respective driving voltages according to each power control signal;

[0072] The driving module is also connected to the push-pull power supply module and is used to generate respective driving signals according to each driving voltage and the corresponding driving control signal.

[0073] It should be noted that the push-pull power supply module can provide driving voltages with different magnitudes for the driving module. After the state detection module locates each transient moment, when it is necessary to adjust the magnitude of the driving voltage, a power control signal can be generated to adjust the magnitude of the driving voltage output from the push-pull power supply module to the driving module.

[0074] Such as Figure 4 shown, the jump moment of the pulse modulation signal includes the rising edge moment and the falling edge moment. According to the rising edge moment and the falling edge moment, the turn-on start moment t 0 and the turn-off start moment t 5。At different transient moments of the power device, the corresponding power supply control signal can control the push-pull power supply module to provide different driving voltages for the driving module, so that when the driving chip receives the driving control signal, it outputs the driving voltages of different magnitudes as driving signals to the gate of the power device. Preferably, the magnitudes of the driving voltages output by the push-pull power supply module include 15V and -8V.

[0075] In a feasible implementation manner, as Figure 3 shown, the transient detection circuit of the power device may further include:

[0076] A level conversion module, connected to the state detection module, for performing level conversion on each driving control signal to obtain a target driving control signal;

[0077] A driving module, connected to the level conversion module, for generating respective corresponding driving signals according to each target driving control signal.

[0078] It should be noted that since there is a difference between the input level of the driving chip and the output level of the FPGA, in order to ensure that the state detection module can reliably control the driving module, the level conversion module can be used to perform level conversion on the driving control signal to ensure that the level magnitude of the target driving control signal meets the input level requirements of the driving chip.

[0079] In a feasible implementation manner, as Figure 3 shown, the transient detection circuit of the power device may further include:

[0080] A power management module, respectively connected to the power supply and the push-pull power supply module, for converting the output voltage of the power supply into a supply voltage to supply power to the push-pull power supply module.

[0081] It should be noted that the supply voltage of the push-pull power supply module is 15V, and this supply voltage is obtained by the power management module converting the output voltage of the power supply. The power supply can be a DC power supply or an AC power supply. The power management module may include a BUCK-BOOST circuit.

[0082] In a feasible implementation manner, as Figure 3 shown, the transient detection circuit of the power device may further include:

[0083] A voltage detection module, connected to the power circuit, for detecting the working voltage of the power device and outputting a voltage detection signal;

[0084] The state detection module is further connected to the voltage detection module, for detecting multiple transient moments of the corresponding power device according to the pulse modulation signal and the voltage detection signal.

[0085] In a feasible implementation manner, as Figure 3As shown in the figure, the transient detection circuit of the power device may further include:

[0086] A temperature detection module, configured to detect the operating temperature of the power device and output a temperature detection signal;

[0087] A state detection module, also connected to the temperature detection module, configured to detect multiple transient moments of the corresponding power device according to the pulse modulation signal, the voltage detection signal, and the temperature detection signal.

[0088] It should be noted that the duration of each transient region of the power device is affected not only by the structure and material of the power device, but also by the operating environment of the power device. Therefore, during the switching process of the power device, the operating voltage, operating temperature, and pulse modulation signal of the power device can also be combined to locate each transient moment.

[0089] It can be understood that the state detection module can locate t according to the pulse modulation signal 0 or t 5 After that, according to the preset interval duration of the power device under different working conditions, locate t 1 -t4 or t6-t 8 , at this time, the state detection module can be implemented by a logic circuit built with FPGA, CPLD or discrete devices; or the state detection module can also locate t according to the pulse modulation signal 0 or t 5 After that, combined with the mathematical model of the power device, according to t 1 , operating voltage and operating temperature, calculate t 1 -t4 or t6-t 8 , at this time, the state detection module can be implemented by FPGA or CPLD. Among them, the preset interval duration under different working conditions can be obtained by testing the power device.

[0090] In the technical solution of this embodiment, the digital signal processing module determines the pulse modulation signals of the power devices in the power circuit according to the power requirements of the power circuit, and the state detection module detects the transient moments corresponding to the respective power devices in different transient regions according to the respective pulse modulation signals. Compared with determining the transient moments corresponding to the power devices in different transient regions according to the drain current of the power device, the pulse modulation signal is not affected by hardware interference and can directly reflect the ideal switching state of the power device, so that the transient moments of the corresponding power devices determined according to the pulse modulation signal are more accurate, improving the accuracy of transient detection of the power device.

[0091] In addition, this embodiment does not require a timing detection circuit, saving hardware costs, being applicable to new energy electric drive products with different powers and currents, and meeting the design goals of product miniaturization, lightweight and platformization.

[0092] In addition, an embodiment of the present application further provides a power device driving device, which may include:

[0093] The transient detection circuit of the power device as described above.

[0094] It should be noted that the specific structure of the transient detection circuit of the power device refers to the above embodiments. Since the transient detection device of the power device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, and will not be elaborated here one by one.

[0095] In addition, an embodiment of the present application further provides a method for detecting the transient state of a power device, which is applied to the transient detection circuit of the power device as described above. As Figure 5 shown, in this embodiment, the method for detecting the transient state of the power device may include steps S100 to S200:

[0096] Step S100: Through a digital signal processing module, generate pulse modulation signals for each power device in the power circuit according to the received power demand of the power circuit.

[0097] Step S200: Through a state detection module, detect the transient moments corresponding to multiple transient regions of the corresponding power device during the switching process according to the pulse modulation signal.

[0098] It should be noted that the specific implementation manner of the method for detecting the transient state of the power device refers to the embodiment of the transient detection circuit of the power device above. Since the method for detecting the transient state of the power device adopts all the technical solutions of all the embodiments of the transient detection circuit of the power device above, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, and will not be elaborated here one by one.

[0099] In a feasible implementation manner, step S200 may include: Through a state detection module, for each power device, during the turn-on process of the power device, use the rising edge moment of the corresponding pulse modulation signal as the turn-on start moment of the power device; according to the turn-on start moment and the mathematical model of the power device, determine other turn-on transient moments of the power device after the turn-on start moment.

[0100] It should be noted that during the turn-on process of the power device, the state detection module may directly use the rising edge moment of the pulse modulation signal as the turn-on start moment t 0 , and thereafter, the state detection module, through the preset mathematical model of the power device, on the basis of the turn-on start moment t 0 , sequentially calculates to obtain other turn-on transient moments t 1 -t 4。The mathematical model of the power device is constructed based on the structure and materials of the power device, etc.

[0101] It can be understood that when constructing the mathematical model of the power device, the influence of the operating voltage and / or operating temperature of the power device can also be considered. During the switching process of the actual power device, the operating voltage and / or operating temperature of the power device are collected in real time, and the mathematical model of the power device is continuously updated and optimized, so that the transient moment calculated according to the mathematical model of the power device is more accurate.

[0102] In a feasible implementation manner, step S200 may include: through the state detection module, for each power device, during the turn-off process of the power device, the first target moment after the first preset duration from the falling edge moment of the corresponding pulse modulation signal is used as the turn-off start moment of the power device; according to the turn-off start moment and the mathematical model of the power device, other turn-off transient moments of the power device after the turn-off start moment are determined.

[0103] It should be noted that during the turn-off process of the power device, the state detection module can directly locate the turn-off start moment t of the power device according to the falling edge moment of the pulse modulation signal 5 , and thereafter, the state detection module passes through the preset mathematical model of the power device, and on the basis of the turn-off start moment t 5 , calculates and obtains other turn-off transient moments t 6 - t 8 .

[0104] It can be understood that since there is a certain transmission time delay when the pulse modulation signal is transmitted from the digital signal processing module to the drive module, therefore, the falling edge moment of the pulse modulation signal actually transmitted to the drive module is later than the falling edge moment of the pulse modulation signal in theory, that is, the turn-off start moment is the falling edge moment of the pulse modulation signal actually transmitted to the drive module. Among them, as Figure 4 shown, the first preset duration is the transmission time delay of the pulse modulation signal, and the first target moment is the falling edge moment of the actual pulse modulation signal actually transmitted to the drive module.

[0105] In a feasible implementation manner, after step S200, the transient detection method of the power device may further include steps S300 to S500:

[0106] Step S300, through the state detection module, generates a plurality of power control signals according to the jump moment of the pulse modulation signal and each transient moment.

[0107] Step S400, through the push-pull power supply module, generates the respective corresponding drive voltages according to each power control signal.

[0108] Step S500: Through the driving module, according to each driving voltage and the corresponding driving control signal, generate respective corresponding driving signals to drive the switching of the power device corresponding to the pulse modulation signal.

[0109] It should be noted that the specific implementation of the transient detection method of this power device refers to the above-mentioned embodiment of the transient detection circuit of the power device. Since the transient detection method of this power device adopts all the technical solutions of all the above-mentioned embodiments of the transient detection circuit of the power device, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, and will not be elaborated one by one here.

[0110] In a feasible implementation, step S300 may include: If the power device is in the turn-on process, through the state detection module, at the second target moment before the second preset duration at the rising edge moment of the pulse modulation signal, generate the first turn-on power control signal; at the target turn-on transient moment among multiple turn-on transient moments, generate the second turn-on power control signal.

[0111] It should be noted that as Figure 4 shown, the trigger edge is the trigger edge of the power control signal. During the turn-on process of the power device, the driving signals with the same voltage are used to drive in region I and region II, and the driving signals with the same voltage are used to drive in region III and region V. The second preset duration is the transmission time delay of the driving voltage, which can be obtained through experiments on the power device. Among them, the second target moment for generating the first turn-on power control signal is the moment before the second preset duration of t 0 , and t 2 is the target turn-on transient moment for generating the second turn-on power control signal.

[0112] It can be understood that when the push-pull power supply module receives the first turn-on power control signal, it outputs the driving voltage corresponding to the first turn-on power control signal to the driving module, and when it receives the second turn-on power control signal, it outputs the driving voltage corresponding to the second turn-on power control signal to the driving module.

[0113] In a feasible implementation, step S300 may include: If the power device is in the turn-off process, through the state detection module, at the falling edge moment of the pulse modulation signal, generate the first turn-off power control signal; at the target turn-off transient moment among multiple turn-off transient moments, generate the second turn-off power control signal.

[0114] It should be noted that as Figure 4 shown, during the turn-off process of the power device, the driving signals with the same voltage are used to drive in region V and region VI, and the driving signals with the same voltage are used to drive in region VII and region VIII. Among them, the falling edge moment of the pulse modulation signal is the moment for generating the first turn-off power control signal, and t 7It is the target turn-off transient moment for generating the second turn-off power control signal.

[0115] It can be understood that when the push-pull power supply module receives the first turn-off power control signal, it outputs the driving voltage corresponding to the first turn-off power control signal to the driving module, and when it receives the second turn-off power control signal, it outputs the driving voltage corresponding to the second turn-off power control signal to the driving module.

[0116] Therefore, this embodiment provides a transient detection method for power devices. The digital signal processing module determines the pulse modulation signals of each power device in the power circuit according to the power requirements of the power circuit. The state detection module detects the transient moments corresponding to the respective power devices in different transient regions according to each pulse modulation signal. Compared with determining the transient moments corresponding to the power devices in different transient regions according to the drain current of the power devices, the pulse modulation signal is not affected by hardware interference and can directly reflect the ideal switching state of the power device, making the transient moments of the corresponding power devices determined according to the pulse modulation signal more accurate and improving the accuracy of the transient detection of the power device.

[0117] In addition, this embodiment does not need to set a timing detection circuit, saving hardware costs, being applicable to new energy electric drive products with different powers and currents, and meeting the design goals of product miniaturization, lightweight, and platformization.

[0118] The above description is only an exemplary embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made using the content of the specification and drawings of the present application under the technical concept of the present application, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A transient detection circuit for a power device, characterized in that: The transient detection circuit of the power device comprises: A digital signal processing module, used for generating a pulse modulation signal for each power device in the power circuit according to the received power demand of the power circuit; The state detection module is connected to the digital signal processing module and is used to detect the transient moments corresponding to the multiple transient regions of the corresponding power device during the switching process according to the pulse modulation signal.

2. The transient detection circuit of a power device according to claim 1, characterized in that: The state detection module is further used to generate a corresponding drive control signal according to each transient moment; The transient detection circuit of the power device further includes: The driving module is connected to the state detection module and the power circuit respectively, and is used to generate corresponding driving signals according to the driving control signals, so as to drive the power device switch corresponding to the pulse modulation signal.

3. The transient detection circuit of a power device according to claim 2, characterized in that: The state detection module is further used to generate a plurality of power control signals according to the jump moment of the pulse modulation signal and each of the transient moments; The transient detection circuit of the power device further includes: A push-pull power supply module, connected to the state detection module, and used to generate respective corresponding driving voltages according to the respective power supply control signals; The driving module is also connected to the push-pull power supply module, and is used to generate the corresponding driving signals according to the driving voltages and the corresponding driving control signals.

4. The transient detection circuit of a power device according to claim 2, characterized in that: The transient detection circuit of the power device further includes: A level conversion module, connected to the state detection module, for performing level conversion on each of the drive control signals to obtain a target drive control signal; The driving module is connected to the level conversion module, and is used to generate the corresponding driving signals according to the target driving control signals.

5. The transient detection circuit of a power device according to claim 3, characterized in that: The transient detection circuit of the power device further includes: The power management module is respectively connected to the power supply and the push-pull power supply module, and is used to convert the output voltage of the power supply into a supply voltage to supply power to the push-pull power supply module.

6. The transient detection circuit of a power device according to claim 1, characterized in that: The transient detection circuit of the power device further includes: A voltage detection module, connected to the power circuit, for detecting the operating voltage of the power device and outputting a voltage detection signal; The state detection module is also connected to the voltage detection module, and is used to detect the corresponding multiple transient moments of the power device according to the pulse modulation signal and the voltage detection signal.

7. The transient detection circuit of a power device according to claim 6, characterized in that: The transient detection circuit of the power device further includes: A temperature detection module, used to detect the operating temperature of the power device and output a temperature detection signal; The state detection module is also connected to the temperature detection module, and is used to detect the corresponding multiple transient moments of the power device according to the pulse modulation signal, the voltage detection signal and the temperature detection signal.

8. A power device driving device, characterized in that: The power device driving device comprises: A transient detection circuit for a power device as claimed in any one of claims 1 to 7.

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