Driving circuit and method of power module

Abstract

The invention discloses a driving circuit and method of a power module. The power module comprises at least two power devices which are connected in parallel; the driving circuit comprises at least two driving modules and at least two temperature acquisition modules; the temperature acquisition module is arranged at the power device, and the driving module is connected with the control end of the power device; the driving module comprises a control unit and a driving unit, the control unit is connected with the corresponding temperature acquisition module, and different control units are in communication connection; the control unit is used for comparing the temperature information of all the power devices, adjusting the conduction time of at least one power device to be later than the conduction time of the other power devices when the difference value between two pieces of temperature information is larger than a preset threshold value, and / or adjusting the conduction time of the other power devices to be later than the conduction time of the other power devices. The driving speed of at least one driving unit is adjusted to be smaller than the driving speed of the other driving units. According to the technical scheme, the loss of the power device is balanced, the temperature unbalance of the power device is avoided, and thus the thermal failure of the power device is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of power modules, and in particular to a driving circuit and method of a power module. Background Art

[0002] Power modules are widely used in the field of power electronics. Power modules can perform power control, power conversion and power regulation, so that the output power meets the load requirements.

[0003] The power module may include at least two power devices connected in parallel, and the power devices may be gallium nitride devices or insulated-gate bipolar transistors (IGBTs). When the power devices are connected in parallel, the electrical parameters of different power devices may be different due to the influence of the process and materials of the power devices, resulting in different losses of different power devices, which may cause temperature imbalance of the power module and eventually lead to thermal failure of the device. Summary of the invention

[0004] The present invention provides a driving circuit and method for a power module to solve the problem that electrical parameters of different power devices may be different, resulting in different losses of different power devices.

[0005] According to one aspect of the present invention, a driving circuit of a power module is provided, wherein the power module comprises at least two power devices connected in parallel; the driving circuit comprises at least two driving modules and at least two temperature acquisition modules;

[0006] The temperature acquisition module is arranged at the power device, and the driving module is connected to the control end of the power device;

[0007] The driving module includes a control unit and a driving unit, the control unit is connected to the corresponding temperature acquisition module, and different control units are communicated with each other; the control unit is used to compare the temperature information of all power devices, and when the difference between two temperature information is greater than a preset threshold, adjust the conduction time of at least one of the power devices to be later than the conduction time of the other power devices, and / or adjust the driving speed of at least one of the driving units to be lower than the driving speed of the other driving units.

[0008] Optionally, when the difference between the two pieces of temperature information is greater than a preset threshold, the first target control unit controls the turn-on time of the corresponding power device to be later than the turn-on time of the other power devices; or, the second target control unit controls the turn-on time of the corresponding power device to be earlier than the turn-on time of the other power devices;

[0009] And / or, the first target control unit controls the driving speed of the corresponding driving unit to be lower than the driving speeds of the remaining driving units; or, the second target control unit controls the driving speed of the corresponding driving unit to be higher than the driving speeds of the remaining driving units;

[0010] Among them, the first target control unit is a control unit whose corresponding temperature information minus any other temperature information has a difference greater than the preset threshold; the second target control unit has a temperature information minus any other temperature information has a difference less than the inverse of the preset threshold.

[0011] Optionally, the control unit includes a first calculator, a pulse generator, a first comparator and a second calculator;

[0012] The first input end of the first calculator is connected to the corresponding temperature acquisition module, the second input end of the first calculator is connected to the communication end of the control unit, and the first calculator is used to calculate a first difference between the temperature information of the corresponding power device and the temperature information received by the communication end;

[0013] A first input terminal of the pulse generator is connected to a triangular wave signal, a second input terminal of the pulse generator is connected to an output terminal of the first calculator, and the pulse generator is used to generate a delayed pulse signal according to the first difference and the triangular wave signal;

[0014] The first input end of the first comparator is connected to the corresponding temperature acquisition module, the second input end of the first comparator is connected to the communication end of the control unit, and the first comparator is used to send an enable signal to the second calculator when the temperature information of the corresponding power device is greater than the temperature information received by the communication end;

[0015] The second calculator receives the initial pulse signal, and is connected to the output terminals of the first comparator and the pulse generator respectively, and is used to generate a target pulse signal according to the delayed pulse signal and the initial pulse signal when receiving the enable signal;

[0016] The driving unit is connected to the second calculator, and is used for generating a driving signal to a corresponding power device according to the target pulse signal.

[0017] Optionally, the first calculator is a subtractor, and the second calculator is a logical AND device.

[0018] Optionally, the control unit includes an encoding subunit; the driving module further includes a plurality of switch units and a plurality of first resistors;

[0019] The first resistor is connected between the first power source and the first end of the switch unit, and the second end of the switch unit is connected to the driving unit;

[0020] The first input end of the encoding subunit is connected to the corresponding temperature acquisition module, the second input end of the encoding subunit is connected to the communication end of the control unit, and the encoding subunit is connected to the control end of the switch unit. The encoding subunit is used to calculate the first difference between the temperature information of the corresponding power device and the temperature information received by the communication end, and determine the encoding value according to the first difference and the preset corresponding relationship, and control the conduction or shutdown of the switch unit according to the encoding value; wherein the preset corresponding relationship is the corresponding relationship between the first difference and the encoding value.

[0021] Optionally, the encoding subunit includes a third calculator, a memory and a controller;

[0022] The first input end of the third calculator is connected to the corresponding temperature acquisition module, the second input end of the third calculator is connected to the communication end of the control unit, and the third calculator is used to calculate the first difference between the temperature information of the corresponding power device and the temperature information received by the communication end;

[0023] The memory is used to store the preset corresponding relationship;

[0024] The controller is connected to the third calculator and the memory respectively, and is used to determine a coding value according to the first difference and a preset corresponding relationship, and control the switching unit to be turned on or off according to the coding value.

[0025] Optionally, the third calculator is a subtractor;

[0026] The switch unit includes a transistor.

[0027] Optionally, the control unit further comprises: a second comparator;

[0028] The first input end of the second comparator is connected to the corresponding temperature acquisition module, the second input end of the second comparator is connected to the communication end of the control unit, the output end of the second comparator is connected to the encoding subunit, and the second comparator is used to send an enable signal to the encoding subunit when the temperature information of the corresponding power device is greater than the temperature information received by the communication end.

[0029] Optionally, the power device, the temperature acquisition module and the driving module are integrated into a power module; or, the power device, the temperature acquisition module and the driving module are independent modules.

[0030] According to another aspect of the present invention, a method for driving a power module is provided. The method for driving a power module is implemented by the driving circuit of the power module according to any embodiment of the present invention. The method includes:

[0031] The control unit compares the temperature information of all power devices;

[0032] When the difference between the two pieces of temperature information is greater than a preset threshold, the control unit adjusts the turn-on time of at least one of the power devices to be later than the turn-on time of the remaining power devices, and / or adjusts the driving speed of at least one of the driving units to be lower than the driving speed of the remaining driving units.

[0033] The technical solution of the embodiment of the present invention is to set a temperature acquisition module at the power device, and the drive module includes a drive unit and a control unit, and different control units are connected by communication. The control unit can obtain the temperature information collected by the temperature acquisition module and the temperature information of other power devices. Then the control unit can compare all the temperature information and calculate the difference between each two temperature information. When the difference between two temperature information is greater than the preset threshold, it indicates that the temperature value corresponding to the temperature information is larger than the temperature value corresponding to other temperature information, that is, the power device has a temperature imbalance problem. At this time, the drive circuit of the power module will adjust the conduction time of at least one power device to be later than the conduction time of the other power devices, and / or adjust the driving speed of at least one drive unit to be less than the driving speed of the other drive units. Thereby reducing the loss of the power device with a larger temperature value, balancing the loss of the power device, making the temperature of different power devices close, avoiding the temperature imbalance of the power device, thereby avoiding the thermal failure of the power device, and improving the reliability and stability of the power module.

[0034] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 is a schematic structural diagram of a driving circuit of a power module provided by an embodiment of the present invention;

[0037] Figure 2is a schematic structural diagram of a driving circuit of another power module provided by an embodiment of the present invention;

[0038] Figure 3 is a driving timing diagram of a power module provided by an embodiment of the present invention;

[0039] Figure 4 is a structural schematic diagram of another driving circuit of a power module provided by an embodiment of the present invention;

[0040] Figure 5 is a driving timing diagram of another power module provided by an embodiment of the present invention;

[0041] Figure 6 is a partial structural schematic diagram of a driving circuit of a power module provided by an embodiment of the present invention;

[0042] Figure 7 is a partial structural schematic diagram of another driving circuit of a power module provided by an embodiment of the present invention;

[0043] Figure 8 is a schematic structural diagram of a driving circuit of another power module provided by an embodiment of the present invention;

[0044] Fig. 9 It is a flow chart of a driving method of a power module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] An embodiment of the present invention provides a driving circuit of a power module. Figure 1 is a schematic diagram of a driving circuit of a power module provided by an embodiment of the present invention, with reference to Figure 1 , the power module 100 includes at least two power devices 110 connected in parallel; the driving circuit includes at least two driving modules 200 and at least two temperature acquisition modules 300;

[0048] The temperature acquisition module 300 is disposed at the power device 110, and the driving module 200 is connected to the control end of the power device 110;

[0049] The driving module 200 includes a control unit 210 and a driving unit 220. The control unit 210 is connected to the corresponding temperature acquisition module 300, and different control units 210 are communicated with each other. The control unit 210 is used to compare the temperature information of all power devices 110, and when the difference between two temperature information is greater than a preset threshold, adjust the turn-on time of at least one power device 110 to be later than the turn-on time of other power devices, and / or adjust the driving speed of at least one driving unit 220 to be lower than the driving speed of other driving units.

[0050] Among them, the power device 110 can be a gallium nitride transistor, or an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET), etc., which is not limited in this embodiment. At least two power devices 110 are connected in parallel, that is, the first ends of all power devices 110 are connected together, the second ends of all power devices 110 are connected together, and the control ends of different power devices 110 are connected to different driving modules 200. For example, the first end of the power module 100 is connected to the second power supply V_BULK, and the second end of the power module 100 is connected to the power ground PGND, that is, the first ends of all power devices 110 are connected to the second power supply V_BULK, and the second ends of all power devices 110 are connected to the power ground PGND.

[0051] Among them, the temperature acquisition module 300 is set in a one-to-one correspondence with the power device 110. The temperature acquisition module 300 is set at the power device 110, and can detect the temperature of the corresponding power device 110, obtain the temperature information of the corresponding power device 110, and send the collected temperature information to the corresponding control unit 210. Then the control unit 210 can obtain the temperature information of the corresponding power device 110, and different control units 210 are connected in communication, and the control unit 210 can obtain the temperature information of the remaining power devices 110, so that each control unit 210 can obtain the temperature information of all power devices 110. Among them, the temperature information can be a temperature value or a voltage value corresponding to the temperature value, which is not limited in this embodiment.

[0052] Exemplarily, each control unit 210 may include multiple communication terminals, including at least one transmitting terminal and at least one receiving terminal, so that each control unit 210 can send temperature information of its corresponding power device 110 to other control units 210, and can also receive temperature information sent by other control units 210.

[0053] Specifically, after acquiring the temperature information of all power devices 110, the control unit 210 can calculate the difference between every two pieces of temperature information. When the difference between two pieces of temperature information is greater than a preset threshold, it indicates that the temperature value corresponding to the temperature information is larger than the temperature values ​​corresponding to other temperature information, that is, the power device 110 has a temperature imbalance problem. At this time, the driving circuit of the power module will adjust the on-time of at least one power device 110 to be later than the on-time of the remaining power devices, and / or adjust the driving speed of at least one driving unit 220 to be lower than the driving speed of the remaining driving units. For example, the on-time of the power device 110 with a larger temperature value is adjusted to be later than the on-time of the remaining power devices, and / or the driving speed of the driving unit 220 corresponding to the power device with a larger temperature value is adjusted to be lower than the driving speed of the remaining driving units.

[0054] Among them, the conduction time of the power device 110 with a larger temperature value is adjusted to be later than the conduction time of the other power devices. The control unit corresponding to the power device 110 with a larger temperature value may control the conduction time of the power device 110 with a larger temperature value to be delayed, or the control unit corresponding to the power device 110 with a smaller temperature value may control the conduction time of the power device 110 with a smaller temperature value to be advanced, which is not limited in this embodiment. Similarly, the driving speed of the driving unit 220 corresponding to the power device with a larger temperature value is adjusted to be lower than the driving speed of the other driving units. The control unit corresponding to the power device with a larger temperature value may control the driving speed of the driving unit 220 to be reduced, or the control unit corresponding to the power device with a smaller temperature value may control the driving speed of the driving unit 220 to be increased, which is not limited in this embodiment.

[0055] In this way, by adjusting the turn-on time of at least one power device 110 to be later than the turn-on time of the other power devices, the turn-on time of the power device 110 with a larger temperature value corresponding to the temperature information can be made later than the turn-on time of the power device 110 with a smaller temperature value. By adjusting the driving speed of at least one driving unit 220 to be lower than the driving speed of the other driving units, the driving speed of the power device 110 with a larger temperature value corresponding to the temperature information can be made lower than the driving speed of the power device 110 with a smaller temperature value, so that the power device 110 with a larger temperature value corresponding to the temperature information is delayed from being turned on, thereby reducing the loss of the power device 110 with a larger temperature value, which is conducive to balancing the loss of the power device 110, making the temperatures of different power devices 110 close to each other, avoiding the temperature imbalance of the power device 110, thereby avoiding the thermal failure of the power device 110, and helping to improve the reliability and stability of the power module 100.

[0056] It should be noted that Figure 1 2 shows a case where the power module 100 includes two power devices 110 , but this is not limiting. Figure 1 The fact that the temperature acquisition module 300 is inside the power module 100 does not mean that the power module 100 includes the temperature acquisition module 300 .

[0057] The technical solution of this embodiment is to set a temperature acquisition module at the power device, and the drive module includes a drive unit and a control unit, and different control units are connected by communication. The control unit can obtain the temperature information collected by the temperature acquisition module, and can obtain the temperature information of other power devices. Then the control unit can compare all the temperature information and calculate the difference between each two temperature information. When the difference between two temperature information is greater than the preset threshold, it indicates that the temperature value corresponding to the temperature information is larger than the temperature value corresponding to other temperature information, that is, the power device has a temperature imbalance problem. At this time, the drive circuit of the power module will adjust the conduction time of at least one power device to be later than the conduction time of the other power devices, and / or adjust the driving speed of at least one drive unit to be less than the driving speed of the other drive units. Thereby reducing the loss of power devices with larger temperature values, which is conducive to balancing the loss of power devices, making the temperatures of different power devices close, avoiding temperature imbalance of power devices, thereby avoiding thermal failure of power devices, and helping to improve the reliability and stability of the power module.

[0058] On the basis of the above technical solution, optionally, when there is a difference between two pieces of temperature information greater than a preset threshold, the first target control unit controls the turn-on time of the corresponding power device 110 to be later than the turn-on time of the remaining power devices 110; or, the second target control unit controls the turn-on time of the corresponding power device 110 to be earlier than the turn-on time of the remaining power devices 110;

[0059] And / or, the first target control unit controls the driving speed of the corresponding driving unit 220 to be lower than the driving speeds of the remaining driving modules; or, the second target control unit controls the driving speed of the corresponding driving unit 220 to be higher than the driving speeds of the remaining driving units;

[0060] Among them, the first target control unit is a control unit whose corresponding temperature information minus any other temperature information has a difference greater than a preset threshold; the second target control unit has a temperature information minus any other temperature information whose difference is less than the opposite of the preset threshold.

[0061] Specifically, for example, the preset threshold is a positive number. The first target control unit is a control unit whose difference between the corresponding temperature information and any other temperature information is greater than the preset threshold, that is, the temperature value of the power device 110 corresponding to the first target control unit is larger. The opposite of the preset threshold is a negative number. The difference between the temperature information corresponding to the second target control unit and any other temperature information is less than the opposite of the preset threshold, that is, the temperature value of the power device corresponding to the second target control unit is smaller. The first target control unit controls the corresponding power device 110 to be turned on later than the other power devices 110; or, the second target control unit controls the corresponding power device 110 to be turned on earlier than the other power devices 110, which can make the power device 110 with a higher temperature turn on later than the other power devices 110, thereby reducing the loss of the power device 110 with a higher temperature, making the temperatures of different power devices 110 close, and avoiding temperature imbalance of the power device 110. The first target control unit controls the driving speed of the corresponding driving unit 220 to be lower than the driving speed of the other driving modules; or, the second target control unit controls the driving speed of the corresponding driving unit 220 to be higher than the driving speed of the other driving units, so that the power device 110 with a higher temperature can be turned on slowly, thereby reducing the loss of the power device 110 with a higher temperature, making the temperatures of different power devices 110 close to each other, and avoiding temperature imbalance of the power device 110.

[0062] On the basis of the above technical solutions, Figure 2 is a schematic diagram of a structure of a driving circuit of another power module provided in an embodiment of the present invention. Figure 2 , the control unit 210 includes a first calculator U1, a pulse generator U2, a first comparator U3 and a second calculator U4;

[0063] A first input end of the first calculator U1 is connected to the corresponding temperature acquisition module 300, and a second input end of the first calculator U1 is connected to the communication end of the control unit 210. The first calculator U1 is used to calculate a first difference between the temperature information of the corresponding power device 110 and the temperature information received by the communication end;

[0064] The first input end of the pulse generator U2 is connected to the triangular wave signal S1, the second input end of the pulse generator U2 is connected to the output end of the first calculator U1, and the pulse generator U2 is used to generate a delayed pulse signal according to the first difference and the triangular wave signal S1;

[0065] The first input end of the first comparator U3 is connected to the corresponding temperature acquisition module 300, and the second input end of the first comparator U3 is connected to the communication end of the control unit 210. The first comparator U3 is used to send an enable signal to the second calculator U4 when the temperature information of the corresponding power device 110 is greater than the temperature information received by the communication end;

[0066] The second calculator U4 is connected to the initial pulse signal P0, and the second calculator U4 is connected to the output end of the first comparator U3 and the pulse generator U2 respectively. The second calculator U4 is used to generate a target pulse signal according to the delayed pulse signal and the initial pulse signal P0 when receiving the enable signal;

[0067] The driving unit 220 is connected to the second calculator U4 , and is used to generate a driving signal to the corresponding power device 110 according to the target pulse signal.

[0068] Specifically, the first calculator U1 can calculate the first difference between the temperature information of the corresponding power device 110 and the temperature information received by the communication end, that is, it can calculate the first difference between the temperature information of the corresponding power device 110 and the temperature information of other power devices 110, thereby comparing the temperature information of the corresponding power device 110 with the temperature information of other power devices 110.

[0069] The pulse generator U2 generates a delayed pulse signal according to the first difference and the triangular wave signal S1. For example, the counter counts up step by step from 0 to 10, and then counts down step by step from 10 to 0 to generate the triangular wave signal S1, and compares the first difference with the triangular wave signal S1, that is, the first difference is compared with the count value to complete the output of high and low levels, thereby outputting a delayed pulse signal. For example, the pulse generator U2 outputs a low-level signal by default, and the first difference is 5. Then, in the process of the triangular wave signal S1 increasing from 0 to 10, when it increases to 5, the pulse delay signal jumps once, and the pulse generator U2 outputs a high level. In the process of the triangular wave signal S1 decreasing from 10 to 0, when it decreases to 5, the pulse delay signal jumps once, and the pulse generator U2 outputs a low level. This is repeated, so that the pulse generator U2 generates a delayed pulse signal. For example, the first difference is 8. In the process of the triangular wave signal S1 increasing from 0 to 10, when it increases to 8, the pulse delay signal jumps once, and the pulse generator U2 outputs a high level. When the triangular wave signal S1 decreases from 10 to 0, the pulse delay signal jumps once and the pulse generator U2 outputs a low level when it decreases to 8. In this way, the larger the first difference is, the later the pulse delay signal outputs a high level, and the larger the first difference is, the later the corresponding power device 110 is turned on, thereby reducing the loss of the power device 110.

[0070] When the temperature information of the corresponding power device 110 is greater than the temperature information received by the communication terminal, the first comparator U3 sends an enable signal to the second calculator U4, and the second calculator U4 generates a target pulse signal according to the delayed pulse signal and the initial pulse signal, so that the time when the target pulse signal jumps to a high level is later than the time when the initial pulse signal jumps to a high level, so that the driving unit 220 delays the generation of a driving signal of an effective level, and then the corresponding power device 110 is delayed to turn on. In this way, the power device 110 with a larger temperature value corresponding to the temperature information is delayed to turn on, so that the first target control unit controls the corresponding power device 110 to turn on later than the other power devices 110, and the temperature of the power device 110 is adjusted. Among them, the effective level is, for example, a high level, and in some other embodiments, the effective level can also be a low level, which is not limited in this embodiment.

[0071] It should be noted that the implementation method of the second target control unit controlling the turn-on time of the corresponding power device 110 to be earlier than the turn-on time of the other power devices 110 is similar to the implementation method of the first target control unit controlling the turn-on time of the corresponding power device 110 to be later than the turn-on time of the other power devices 110, and will not be repeated here.

[0072] Optionally, refer to Figure 2 , the first calculator U1 is a subtractor, and the second calculator U4 is a logic AND device.

[0073] Specifically, the first calculator U1 is a subtractor, and the difference between the two temperature information can be calculated, that is, the first difference between the temperature information of the corresponding power device 110 and the temperature information received by the communication terminal can be calculated. The second calculator U4 is a logic and device, that is, an AND gate, and the second calculator U4 can perform a logic and operation on the initial pulse signal and the delayed pulse signal, so that the initial pulse signal jumps to a high level, but when the delayed pulse signal does not jump to a high level, the second calculator U4 outputs a low level signal, and when the initial pulse signal outputs a high level and the delayed pulse signal jumps to a high level, the target pulse signal output by the second calculator U4 will jump to a high level, thereby delaying the initial pulse signal according to the delayed pulse signal, and obtaining the target pulse signal, so that the corresponding power device 110 can be delayed to turn on, so as to be later than the turn-on time of other power devices 110.

[0074] Exemplarily, the power module 100 includes two power devices 110 , wherein one power device includes a first gallium nitride transistor Q1 , and the other power device includes a second gallium nitride transistor Q2 .

[0075] Figure 3 is a driving timing diagram of a power module provided by an embodiment of the present invention. Optionally, refer to Figure 3 At time t1, the temperatures of the first gallium nitride transistor Q1 and the second gallium nitride transistor Q2 are the same, the pulse signal P1 corresponding to the first gallium nitride transistor Q1 and the pulse signal P2 corresponding to the second gallium nitride transistor Q2 are initial pulse signals, and the first gallium nitride transistor Q1 and the second gallium nitride transistor Q2 are turned on at the same time. At time t2, the first difference between the temperature information of the first gallium nitride transistor Q1 and the temperature information of the second gallium nitride transistor Q2 is greater than the preset threshold, then the control unit 210 corresponding to the first gallium nitride transistor Q1 generates a target pulse signal, and controls the first gallium nitride transistor Q1 according to the delayed target pulse signal, and the first gallium nitride transistor Q1 is turned on only at time t3, and the control unit corresponding to the second gallium nitride transistor Q2 controls the second gallium nitride transistor Q2 according to the initial pulse signal, so that the first gallium nitride transistor Q1 is turned on with delay, thereby reducing the loss of the first gallium nitride transistor Q1, and at time t4, the temperatures of the first gallium nitride transistor Q1 and the second gallium nitride transistor Q2 are restored to be consistent, achieving temperature balance. After time t4, the pulse signal corresponding to the first gallium nitride transistor Q1 can be adjusted to an initial pulse signal.

[0076] On the basis of the above technical solutions, Figure 4 is a schematic diagram of a structure of a driving circuit of another power module provided in an embodiment of the present invention. Figure 4, the control unit 210 includes a coding subunit 211; the driving module 200 also includes a plurality of switch units 230 and a plurality of first resistors R1;

[0077] The first resistor R1 is connected between the first power source V1 and the first end of the switch unit 230, and the second end of the switch unit 230 is connected to the driving unit 220;

[0078] The first input end of the encoding subunit 211 is connected to the corresponding temperature acquisition module 300, the second input end of the encoding subunit 211 is connected to the communication end of the control unit 210, and the encoding subunit 211 is connected to the control end of the switch unit. The encoding subunit 211 is used to calculate the first difference between the temperature information of the corresponding power device 110 and the temperature information received by the communication end, and determine the encoding value according to the first difference and the preset corresponding relationship, and control the conduction or shutdown of the switch unit 230 according to the encoding value; wherein the preset corresponding relationship is the corresponding relationship between the first difference and the encoding value.

[0079] Specifically, the preset corresponding relationship can be a curve graph or a table, which is not limited in this embodiment. The encoding subunit 211 calculates the first difference between the temperature information of the corresponding power device 110 and the temperature information received by the communication terminal, searches for the encoding value from the preset corresponding relationship according to the first difference, and controls the on or off of each switch unit 230 according to the encoding value, thereby controlling the number of first resistors R1 connected to the circuit, and then controlling the driving current of the driving unit 220, thereby adjusting the driving speed of the driving unit 220. The smaller the driving current, the slower the driving speed of the driving unit 220, and the slower the corresponding power device 110 is turned on.

[0080] Exemplarily, the number of bits of the coding value is the same as the number of switch units 230, and each bit of the coding value corresponds to a switch unit 230, so that whether the corresponding switch unit 230 is turned on can be controlled according to the value of each bit of the coding value. For example, when the value in the coding value is a high level, the corresponding switch unit 230 is turned on, and when the value of the coding value is a low level, the corresponding switch unit 230 is turned off. For example, the driving module 200 includes eight switch units 230 and eight first resistors R1. When the first difference is a, the corresponding coding value is 00001111, then the coding subunit 211 controls four switch units 230 to be turned on, and the four first resistors R1 are connected to the circuit; when the first difference is b (b is greater than a), the corresponding coding value is 00000011, then the coding subunit 211 controls two switch units 230 to be turned on, then the two first resistors R1 are connected to the circuit, the number of parallel first resistors R1 is reduced, and the total resistance value is increased, so that the driving current is reduced, then the driving speed of the driving unit 220 is reduced, and the corresponding power device 110 is turned on more slowly, thereby reducing the loss of the corresponding power device 110.

[0081] Optionally, refer to Figure 4 , the encoding subunit 211 includes a third calculator U5, a memory U6 ​​and a controller U7;

[0082] A first input end of the third calculator U5 is connected to the corresponding temperature acquisition module 300, and a second input end of the third calculator U5 is connected to the communication end of the control unit 210. The third calculator U5 is used to calculate a first difference between the temperature information of the corresponding power device and the temperature information received by the communication end;

[0083] The memory U6 ​​is used to store the preset corresponding relationship;

[0084] The controller U7 is connected to the third calculator U5 and the memory U6 ​​respectively. The controller U7 is used to determine the coding value according to the first difference and the preset corresponding relationship, and control the switching unit 230 to be turned on or off according to the coding value.

[0085] Specifically, the third calculator U5 can calculate the first difference between the temperature information of the corresponding power device 110 and the temperature information received by the communication end, that is, it can calculate the first difference between the temperature information of the corresponding power device 110 and the temperature information of other power devices 110, thereby comparing the temperature information of the corresponding power device 110 with the temperature information of other power devices 110.

[0086] The memory U6 ​​may be a flash memory, a read-only memory (ROM), or other types of memory, which is not limited in this embodiment. The memory U6 ​​stores a preset correspondence, so that the controller U7 can read the encoding value corresponding to the first difference from the memory U6 ​​according to the first difference, thereby controlling the switch unit 230 according to the encoding value. The controller U7 may include a control chip, which may be a single-chip microcomputer chip, i.e., a single-chip microcontroller chip, or other types of control chips, which are not limited in this embodiment.

[0087] Optionally, refer to Figure 4 , the third calculator U5 is a subtractor; the switch unit 230 includes a transistor.

[0088] Specifically, the third calculator U5 is a subtractor, and can calculate the first difference between the temperature information of the corresponding power device 110 and the temperature information received by the communication terminal. The switch unit 230 includes a transistor, which can be a triode or a field effect transistor, etc., which is not limited in this embodiment.

[0089] Optionally, refer to Figure 4 , the control unit 210 further includes: a second comparator U8;

[0090] The first input end of the second comparator U8 is connected to the corresponding temperature acquisition module 300, the second input end of the second comparator U8 is connected to the communication end of the control unit 210, and the output end of the second comparator U8 is connected to the encoding subunit 211. The second comparator U8 is used to send an enable signal to the encoding subunit 211 when the temperature information of the corresponding power device 110 is greater than the temperature information received at the communication end.

[0091] Specifically, when the temperature information of the corresponding power device 110 is greater than the temperature information received by the communication end, the second comparator U8 sends an enable signal to the coding sub-unit 211, and the coding sub-unit 211 calculates the first difference between the temperature information of the corresponding power device 110 and the temperature information received by the communication end, and determines the coding value according to the first difference and the preset corresponding relationship, and controls the conduction or shutdown of the switch unit 230 according to the coding value to realize the control of the driving current.

[0092] The output end of the second comparator U8 is connected to the encoding subunit 211, and specifically can be connected to the controller U7 in the encoding subunit 211. When the temperature information of the corresponding power device 110 is greater than the temperature information received by the communication end, the second comparator U8 sends an enable signal to the controller U7, so that the controller U7 obtains the corresponding encoding value from the memory U6 ​​according to the first difference, and controls the on or off of the switch unit 230 according to the encoding value, thereby controlling the driving current.

[0093] Optionally, refer to Figure 4 The control unit 210 further includes: a first isolator U9; the first isolator U9 receives the initial pulse signal P0, and the first isolator U9 is connected to the driving unit 220. In this way, the initial pulse signal P0 can be transmitted to the driving unit 220 through the first isolator U9.

[0094] Exemplarily, the power module 100 includes two power devices 110 , wherein one power device includes a first gallium nitride transistor Q1 , and the other power device includes a second gallium nitride transistor Q2 .

[0095] Figure 5 is another driving timing diagram of a power module provided by an embodiment of the present invention, such as Figure 5As shown, at time t1', the temperature of the first gallium nitride transistor Q1 and the second gallium nitride transistor Q2 are the same, and the pulse signal P1 corresponding to the first gallium nitride transistor Q1 and the pulse signal P2 corresponding to the second gallium nitride transistor Q2 have the same slope in the process of jumping to a high level, that is, the driving speed is the same, and the first gallium nitride transistor Q1 and the second gallium nitride transistor Q2 are turned on at the same time. At time t2', the first difference between the temperature information of the first gallium nitride transistor Q1 and the temperature information of the second gallium nitride transistor Q2 is greater than the preset threshold, then the driving speed of the driving unit 220 corresponding to the first gallium nitride transistor Q1 is relatively low, so that the first gallium nitride transistor Q1 is delayed from being turned on, thereby reducing the loss of the first gallium nitride transistor Q1. At time t3', the temperatures of the first gallium nitride transistor Q1 and the second gallium nitride transistor Q2 are restored to be consistent, achieving temperature balance.

[0096] It should be noted that in order to express the change of driving speed, Figure 5 It is shown in FIG. 1 that the slope of the pulse signal P1 corresponding to the first gallium nitride transistor Q1 is obvious, but the slope and driving speed of the pulse signal P1 corresponding to the first gallium nitride transistor Q1 are not limited.

[0097] On the basis of the above technical solutions, optionally, refer to Figure 2 or Figure 4 The temperature acquisition module 300 includes a second resistor R2 and a third resistor R3, the first end of the second resistor R2 is connected to the third power supply V3, the second end of the second resistor R2 is connected to the first end of the third resistor R3, the second end of the third resistor R3 is connected to the power ground GND, and the first end of the third resistor R3 is connected to the corresponding control unit 210; wherein the third resistor R3 is a thermistor.

[0098] Specifically, the third resistor R3 is a thermistor, and the resistance of the third resistor R3 will change with the change of temperature. The temperature acquisition module 300 is set at the power device 110, and the resistance of the third resistor R3 will change with the change of the temperature of the power device 110. The control unit 210 obtains the voltage value of the first end of the third resistor R3, which is the voltage value corresponding to the temperature information. The voltage values ​​corresponding to the temperature information of different power devices 110 are compared, and the temperature information of different power devices 110 can be compared, which is convenient for adjusting the conduction time of the power device 110 according to the temperature information of the power device 110, and convenient for adjusting the driving speed of the driving unit 220 according to the temperature information of the power device 110, thereby achieving temperature balance of the power device 110.

[0099] Optionally, refer to Figure 2 or Figure 4, the first output end of the driving unit 220 and the second output end of the driving unit 220 are both connected to the power device 110, the first output end of the driving unit 220 is used to output the first driving signal, and the second output end of the driving unit 220 is used to output the second driving signal. Wherein, for example, the first driving signal is a high-level signal and the second driving signal is a low-level signal, then when the control unit 210 outputs the target pulse signal, the driving unit 220 outputs the first driving signal with a time delay, so that the corresponding power device 110 is delayed in conducting.

[0100] On the basis of the above technical solutions, in one implementation mode, Figure 6 is a partial structural diagram of a driving circuit of a power module provided in an embodiment of the present invention. Optionally, refer to Figure 6 The power device 110, the temperature acquisition module 300 and the driving module 200 are integrated into a power module 10. In this way, the integration of the driving circuit of the power module can be improved, and the driving circuit of the power module can be used as a whole for easy use.

[0101] In another embodiment, Figure 7 is a partial structural diagram of another driving circuit of a power module provided in an embodiment of the present invention. Figure 7 , the power device 110, the temperature acquisition module 300 and the driving module 200 are independent modules. In this way, the required modules can be selected according to the requirements. For example, when the stability of the driving circuit is required to be high, the power device 110, the temperature acquisition module 300 and the driving module 200 can be used at the same time. When the cost of the driving circuit is required to be low, the power device 110 and the driving module 200 can be used. The modules can also be selected according to the actual situation, which is not limited in this embodiment.

[0102] Alternatively, if Figure 6 or Figure 7 As shown, the control unit 210 is connected to the initial pulse signal P0 and the initial inverted signal P0B, and the control unit 210 is correspondingly connected to two driving units 220, and can control the two driving units 220 to generate driving signals to achieve driving of the two power devices 110. Among them, the initial pulse signal P0 and the initial inverted signal P0B are inverted signals to each other, and can drive the two power devices 110 to be complementary.

[0103] When controlling the power device 110 corresponding to the initial inverted signal P0B to delay turning on, the transition time of the initial inverted signal P0B may be delayed according to the generation method of the target pulse signal.

[0104] Alternatively, if Figure 6 or Figure 7As shown, the driving module 200 further includes a first power supply unit 240 and a second power supply unit 250. The first power supply unit 240 is connected to an external power supply, and the first power supply unit 240 is connected to the driving unit 220. The first power supply unit 240 is used to provide a first power supply V1 for the driving unit 220. The second power supply unit 250 is connected to an external power supply, and the second power supply unit 250 is connected to the control unit 210. The second power supply unit 250 is used to supply power to the control unit 210. The first power supply unit 240 and the second power supply unit 250 may include a DC-DC converter or a low-dropout regulator (LDO), which is not limited in this embodiment.

[0105] On the basis of the above technical solutions, Figure 8 is a schematic diagram of a structure of a driving circuit of another power module provided in an embodiment of the present invention. Figure 8 The driving circuit of the power module also includes a second isolator U10; the driving module 200 receives the initial pulse signal P0 through the second isolator U10. In this way, the external control device and the driving circuit can be isolated to prevent the large power or voltage on one side of the driving circuit from affecting the external control device.

[0106] An embodiment of the present invention further provides a method for driving a power module. The method for driving a power module is implemented by a driving circuit for a power module provided by any implementation scheme of the present invention. Fig. 9 is a flowchart of a method for driving a power module provided by an embodiment of the present invention, with reference to Fig. 9 , the driving method of the power module includes:

[0107] S101 . The control unit compares the temperature information of all power devices.

[0108] Specifically, Figure 1 As shown, the temperature acquisition module 300 is arranged at the power device 110, and can detect the temperature of the corresponding power device 110, obtain the temperature information of the corresponding power device 110, and send the collected temperature information to the corresponding control unit 210. Then the control unit 210 can obtain the temperature information of the corresponding power device 110, and different control units 210 are connected in communication, and the control unit 210 can obtain the temperature information of the remaining power devices 110, so that each control unit 210 can obtain the temperature information of all power devices 110. After obtaining the temperature information of all power devices 110, the control unit 210 can calculate the difference between each two pieces of temperature information to compare the temperature information of all power devices.

[0109] S102: When the difference between two pieces of temperature information is greater than a preset threshold, the control unit adjusts the turn-on time of at least one power device to be later than the turn-on time of other power devices, and / or adjusts the driving speed of at least one driving unit to be lower than the driving speed of other driving units.

[0110] Specifically, Figure 1 As shown, after the control unit 210 obtains the temperature information of all power devices 110, it can calculate the difference between every two pieces of temperature information. When the difference between two pieces of temperature information is greater than a preset threshold, it indicates that the temperature value corresponding to the temperature information is larger than the temperature values ​​corresponding to other temperature information, that is, the power device 110 has a temperature imbalance problem. At this time, the driving circuit of the power module will adjust the on-time of at least one power device 110 to be later than the on-time of the other power devices, and / or adjust the driving speed of at least one driving unit 220 to be lower than the driving speed of the other driving units. In this way, by adjusting the on-time of at least one power device 110 to be later than the on-time of the other power devices, the on-time of the power device 110 with a larger temperature value corresponding to the temperature information can be made to be later than the on-time of the power device 110 with a smaller temperature value. By adjusting the driving speed of at least one driving unit 220 to be lower than the driving speeds of the remaining driving units, the driving speed of the power device 110 having a larger temperature value corresponding to the temperature information can be made lower than the driving speed of the power device 110 having a smaller temperature value, so that the power device 110 having a larger temperature value corresponding to the temperature information is delayed from being turned on, thereby reducing the loss of the power device 110 having a larger temperature value, which is beneficial to balancing the loss of the power device 110, making the temperatures of different power devices 110 close to each other, avoiding temperature imbalance of the power device 110, thereby avoiding thermal failure of the power device 110, and helping to improve the reliability and stability of the power module 100.

[0111] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0112] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A driving circuit of a power module, characterized in that: The power module includes at least two power devices connected in parallel; the drive circuit includes at least two drive modules and at least two temperature acquisition modules; The temperature acquisition module is arranged at the power device, and the driving module is connected to the control end of the power device; The driving module includes a control unit and a driving unit, the control unit is connected to the corresponding temperature acquisition module, and different control units are communicated with each other; the control unit is used to compare the temperature information of all power devices, and when the difference between two temperature information is greater than a preset threshold, adjust the conduction time of at least one of the power devices to be later than the conduction time of the other power devices, and / or adjust the driving speed of at least one of the driving units to be lower than the driving speed of the other driving units.

2. The driving circuit of the power module according to claim 1, characterized in that: When the difference between the two pieces of temperature information is greater than a preset threshold, the first target control unit controls the turn-on time of the corresponding power device to be later than the turn-on time of the other power devices; or the second target control unit controls the turn-on time of the corresponding power device to be earlier than the turn-on time of the other power devices; And / or, the first target control unit controls the driving speed of the corresponding driving unit to be lower than the driving speeds of the remaining driving units; or, the second target control unit controls the driving speed of the corresponding driving unit to be higher than the driving speeds of the remaining driving units; Among them, the first target control unit is a control unit whose corresponding temperature information minus any other temperature information has a difference greater than the preset threshold; the second target control unit has a temperature information minus any other temperature information has a difference less than the inverse of the preset threshold.

3. The driving circuit of the power module according to claim 1, characterized in that: The control unit includes a first calculator, a pulse generator, a first comparator, and a second calculator; The first input end of the first calculator is connected to the corresponding temperature acquisition module, the second input end of the first calculator is connected to the communication end of the control unit, and the first calculator is used to calculate a first difference between the temperature information of the corresponding power device and the temperature information received by the communication end; A first input terminal of the pulse generator is connected to a triangular wave signal, a second input terminal of the pulse generator is connected to an output terminal of the first calculator, and the pulse generator is used to generate a delayed pulse signal according to the first difference and the triangular wave signal; The first input end of the first comparator is connected to the corresponding temperature acquisition module, the second input end of the first comparator is connected to the communication end of the control unit, and the first comparator is used to send an enable signal to the second calculator when the temperature information of the corresponding power device is greater than the temperature information received by the communication end; The second calculator receives the initial pulse signal, and is connected to the output terminals of the first comparator and the pulse generator respectively, and is used to generate a target pulse signal according to the delayed pulse signal and the initial pulse signal when receiving the enable signal; The driving unit is connected to the second calculator, and is used for generating a driving signal to a corresponding power device according to the target pulse signal.

4. The driving circuit of the power module according to claim 3, characterized in that: The first calculator is a subtractor, and the second calculator is a logical AND device.

5. The driving circuit of the power module according to claim 1, characterized in that: The control unit includes an encoding subunit; the driving module also includes a plurality of switch units and a plurality of first resistors; The first resistor is connected between the first power source and the first end of the switch unit, and the second end of the switch unit is connected to the driving unit; The first input end of the encoding subunit is connected to the corresponding temperature acquisition module, the second input end of the encoding subunit is connected to the communication end of the control unit, and the encoding subunit is connected to the control end of the switch unit. The encoding subunit is used to calculate the first difference between the temperature information of the corresponding power device and the temperature information received by the communication end, and determine the encoding value according to the first difference and the preset corresponding relationship, and control the conduction or shutdown of the switch unit according to the encoding value; wherein the preset corresponding relationship is the corresponding relationship between the first difference and the encoding value.

6. The driving circuit of the power module according to claim 5, characterized in that: The encoding subunit includes a third calculator, a memory and a controller; The first input end of the third calculator is connected to the corresponding temperature acquisition module, the second input end of the third calculator is connected to the communication end of the control unit, and the third calculator is used to calculate the first difference between the temperature information of the corresponding power device and the temperature information received by the communication end; The memory is used to store the preset corresponding relationship; The controller is connected to the third calculator and the memory respectively, and is used to determine a coding value according to the first difference and a preset corresponding relationship, and control the switching unit to be turned on or off according to the coding value.

7. The driving circuit of the power module according to claim 6, characterized in that: The third calculator is a subtractor; The switch unit includes a transistor.

8. The driving circuit of the power module according to claim 5, characterized in that: The control unit further comprises: a second comparator; The first input end of the second comparator is connected to the corresponding temperature acquisition module, the second input end of the second comparator is connected to the communication end of the control unit, the output end of the second comparator is connected to the encoding subunit, and the second comparator is used to send an enable signal to the encoding subunit when the temperature information of the corresponding power device is greater than the temperature information received by the communication end.

9. The driving circuit of the power module according to any one of claims 1 to 8, characterized in that: The power device, the temperature acquisition module and the driving module are integrated into a power module; or, the power device, the temperature acquisition module and the driving module are independent modules.

10. A method for driving a power module, characterized in that: The method is implemented by the driving circuit of the power module according to any one of claims 1 to 9, and the method comprises: The control unit compares the temperature information of all power devices; When the difference between the two pieces of temperature information is greater than a preset threshold, the control unit adjusts the turn-on time of at least one of the power devices to be later than the turn-on time of the remaining power devices, and / or adjusts the driving speed of at least one of the driving units to be lower than the driving speed of the remaining driving units.

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