Power module driving circuit

Abstract

The utility model discloses a power module driving circuit, and relates to the technical field of power module driving, and the power module driving circuit comprises a power module; the voltage sampling module is connected with the power module and is used for sampling bus voltage of the power module; the current sampling module is connected with the power module and is used for sampling current flowing through the power module; the isolation driving module is respectively connected with the voltage sampling module and the current sampling module and is used for carrying out logic processing according to the voltage sampling signal and the current sampling signal; and the turn-off channel module is respectively connected with the isolation driving module and the power module and is used for providing a plurality of turn-off channels with different performances between the isolation driving module and the power module and carrying out channel switching among the plurality of turn-off channels according to the channel switching signal so as to drive the power module to be turned off. The effect that the turn-off loss of the power module is not increased or not obviously increased while the voltage stress of the power module is restrained is achieved.

Description

Technical Field

[0001] The present application relates to the field of power module driving technology, and in particular to a power module driving circuit. Background Art

[0002] The power module drive circuit is the circuit that drives the power module on and off. In current power module drive circuits, the drive resistor determines the switching speed and switching losses of the power module during the switching process. In related technologies, increasing the drive resistor can suppress the voltage stress of the power module, but this approach increases the power module's turn-off losses.

[0003] Therefore, how to suppress the voltage stress of the power module without increasing the turn-off loss of the power module is a technical problem that needs to be solved urgently. Utility Model Content

[0004] The main purpose of this application is to provide a power module driving circuit, aiming to solve the technical problem in the related art of how to suppress the voltage stress of the power module without increasing the turn-off loss of the power module.

[0005] To achieve the above objectives, the present application proposes a power module driving circuit, comprising:

[0006] Power modules;

[0007] The voltage sampling module is connected to the power module and is used to sample the bus voltage of the power module and output a voltage sampling signal;

[0008] The current sampling module is connected to the power module and is used to sample the current flowing through the power module and output a current sampling signal;

[0009] The isolation drive module is connected to the voltage sampling module and the current sampling module respectively. The isolation drive module is used to perform logic processing according to the voltage sampling signal and the current sampling signal and output a channel switching signal;

[0010] The shutdown channel module is connected to the control end of the isolation drive module and the power module respectively. The shutdown channel module is used to provide multiple shutdown channels with different performances between the isolation drive module and the power module, and to switch between the multiple shutdown channels according to the channel switching signal to drive the power module to shut down.

[0011] In one embodiment, the isolation driver module includes:

[0012] An overvoltage protection unit is connected to the voltage sampling module, and is used to compare the voltage sampling signal with a preset voltage signal and output an overvoltage protection signal;

[0013] An overcurrent protection unit is connected to the current sampling module, and is used to compare the current sampling signal with the preset current signal and output an overcurrent protection signal;

[0014] The logic switching unit is connected to the overvoltage protection unit and the overcurrent protection unit respectively. The logic switching unit is used to perform logic OR processing according to the overvoltage protection signal and the overcurrent protection signal, and output a corresponding channel switching signal.

[0015] In one embodiment, the voltage sampling module includes a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R9 and a capacitor C1;

[0016] One end of the resistor R5 and the input end of the power module are both connected to the DC bus, the other end of the resistor R5 is connected to one end of the resistor R7 through the resistor R6, the other end of the resistor R7 is respectively connected to one end of the resistor R4 and one end of the resistor R9, the other end of the resistor R4 is respectively connected to one end of the capacitor C1 and the first end of the isolation drive module, and the other end of the capacitor C1, the other end of the resistor R9 and the first output end of the power module are all grounded.

[0017] In one embodiment, the current sampling module includes a resistor R10, a resistor R11 and a capacitor C2;

[0018] One end of the resistor R10 is connected to the second output end of the power module and one end of the resistor R11 respectively, the other end of the resistor R10 is connected to one end of the capacitor C2 and the second end of the isolation drive module respectively, and the other end of the capacitor C2 and the other end of the resistor R11 are both grounded.

[0019] In one embodiment, the shutdown channels with different performances include shutdown resistance channels with different resistance values, voltage shutdown channels with different impedances, current shutdown channels with different currents, or negative pressure shutdown channels with different negative voltages.

[0020] In one embodiment, the shutoff channel module includes a single-connection multi-control switch G1 and a plurality of shutoff resistors with different resistance values;

[0021] One end of the switch G1 is a coupling contact connected to the output end of the isolation drive module. The other end of the switch G1 includes multiple control contacts, which are respectively connected to one end of multiple off-resistors. The other ends of the multiple off-resistors are all connected to the control end of the power module.

[0022] The switch G1 is used for switching to connect any one of the plurality of turn-off resistors according to a channel switching signal, so as to switch to the corresponding turn-off resistor channel.

[0023] In one embodiment, the power module driving circuit further includes:

[0024] The temperature sampling module is provided on the power module and is used to sample the temperature of the power module and output a temperature sampling signal;

[0025] The isolation drive module is also connected to the temperature sampling module. The isolation drive module is also used to perform logic processing according to the voltage sampling signal, the current sampling signal and the temperature sampling signal, and output a channel switching signal.

[0026] In one embodiment, the isolation driver module includes:

[0027] An overvoltage protection unit is connected to the voltage sampling module, and is used to compare the voltage sampling signal with a preset voltage signal and output an overvoltage protection signal;

[0028] An overcurrent protection unit is connected to the current sampling module, and is used to compare the current sampling signal with the preset current signal and output an overcurrent protection signal;

[0029] An over-temperature protection unit is connected to the temperature sampling module, and is used to compare the temperature sampling signal with a preset threshold signal and output an over-temperature protection signal;

[0030] The logic switching unit is connected to the overvoltage protection unit, the overcurrent protection unit and the overtemperature protection unit respectively. The logic switching unit is used to perform logic or processing according to the overvoltage protection signal, the overcurrent protection signal and the overtemperature protection signal, and output the corresponding channel switching signal.

[0031] In one embodiment, the power module driving circuit further includes:

[0032] A short-circuit detection module is connected to the power module and is used to detect a short circuit in the power module and output a short-circuit detection signal;

[0033] The isolation drive module is also connected to the short-circuit detection module. The isolation drive module is also used to perform logic processing according to the voltage sampling signal, the current sampling signal and the short-circuit detection signal, and output a channel switching signal.

[0034] In one embodiment, the isolation driver module includes:

[0035] An overvoltage protection unit is connected to the voltage sampling module, and is used to compare the voltage sampling signal with a preset voltage signal and output an overvoltage protection signal;

[0036] An overcurrent protection unit is connected to the current sampling module, and is used to compare the current sampling signal with the preset current signal and output an overcurrent protection signal;

[0037] An overload protection unit is connected to the short-circuit detection module, and is used to compare the short-circuit detection signal with a preset reference signal and output an overload protection signal;

[0038] The logic switching unit is connected to the overvoltage protection unit, the overcurrent protection unit and the overload protection unit respectively. The logic switching unit is used to perform logic or processing according to the overvoltage protection signal, the overcurrent protection signal and the overload protection signal, and output the corresponding channel switching signal.

[0039] One or more technical solutions proposed in this application have at least the following technical effects:

[0040] A power module driving circuit is proposed, in which the bus voltage of the power module is sampled by a voltage sampling module and the current flowing through the power module is sampled by a current sampling module. The isolation driving module then performs logic processing based on the voltage sampling signal and the current sampling signal, and outputs a channel switching signal, so that the shutdown channel module switches channels between multiple shutdown channels with different performances provided between the isolation driving module and the power module according to the channel switching signal, so as to drive the power module to shut down, thereby achieving the purpose of avoiding overstress of the power module. In this circuit, the power module driving circuit itself is used to sample voltage and current, and no additional external detection circuit is required, which can avoid excessive cost increase. In this case, the switching of the shutdown channel is also achieved through the integrated isolation driving module, which can quickly realize sampling and reduce switching delay, so that the shutdown stress of the power module can be timely and effectively suppressed, thereby achieving the effect of suppressing the voltage stress of the power module without increasing or significantly increasing the shutdown loss of the power module. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative work.

[0042] Figure 1 A connection diagram of a power module drive circuit in the related art;

[0043] Figure 2 This is a connection diagram of an embodiment of a power module driving circuit provided by this application;

[0044] Figure 3 A connection diagram of another embodiment of the power module driving circuit provided by this application;

[0045] Figure 4 A connection diagram of another embodiment of the power module drive circuit provided by this application;

[0046] Figure 5 This is a connection diagram of a specific application example of the power module drive circuit provided in this application.

[0047] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0048] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0049] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application, the directional indications are only used to explain the relative positional relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly. In addition, if there are descriptions of "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0050] The power module driver circuit is the circuit that turns the power module on and off. Currently, most power module driver circuits use a conventional drive method that connects a constant drive resistor to a constant drive voltage. In this method, the drive resistor determines the switching speed and switching losses of the power module during switching. Increasing the switching speed of the power module by adjusting the drive resistor increases the voltage stress on the power module, which may cause the power module to fail due to overstress.

[0051] To this end, the voltage stress of the power module can be suppressed by increasing the driving resistance, such as Figure 1 Figure 1 shows a connection diagram of a power module drive circuit in related art. The drive circuit of power module Q01 consists of a sequentially connected driver chip U01, a switch G01, and three parallel drive resistors R01, R02, and R03. This approach allows switching between multiple drive resistors to suppress voltage stress in the power module, but this approach also increases the power module's turn-off losses. Therefore, finding a way to suppress voltage stress in the power module without increasing its turn-off losses is a pressing technical challenge.

[0052] Moreover, for the above Figure 1 The drive circuit requires additional gate voltage detection circuit and collector or drain voltage detection circuit to determine the switching of the drive resistor, and an additional comparison circuit needs to be added, which increases the cost to a certain extent. Moreover, most of these added circuits are set outside the drive circuit, which makes the voltage sampling of the front stage of the driver chip have a certain delay, resulting in untimely drive response of the power module.

[0053] In response to the above problems, the present application provides a power module driving circuit.

[0054] In one embodiment of the present application, refer to Figure 2 , Figure 2 This is a connection diagram of an embodiment of a power module driving circuit. The power module driving circuit includes a power module, a voltage sampling module, a current sampling module, an isolation driving module and a shutdown channel module.

[0055] Among them, the voltage sampling module is connected to the power module, the current sampling module is connected to the power module, the isolation drive module is connected to the voltage sampling module and the current sampling module respectively, and the shutdown channel module is connected to the control end of the isolation drive module and the power module respectively;

[0056] The voltage sampling module is used to sample the bus voltage of the power module and output a voltage sampling signal;

[0057] The current sampling module is used to sample the current flowing through the power module and output a current sampling signal;

[0058] The isolation driver module is used to perform logic processing based on the voltage sampling signal and the current sampling signal and output the channel switching signal;

[0059] The shutdown channel module is used to provide multiple shutdown channels with different performances between the isolation drive module and the power module, and to switch channels between the multiple shutdown channels according to the channel switching signal to drive the power module to shut down.

[0060] It should be noted that both the voltage sampling signal and the current sampling signal are input to the isolation driver module. The isolation driver module can adopt an integrated design with integrated overvoltage protection and overcurrent protection functions. Overvoltage and overcurrent detection can be implemented on the high-voltage side of the isolation device inside the isolation driver module. The detection results are then used to perform corresponding logical processing to generate and output a channel switching signal. The multiple shutdown channels with different performances provided by the shutdown channel module refer to multiple channels with different parameters, or multiple channels with increasing or decreasing parameters. For example, multiple channels corresponding to multiple driving resistors with increasing or decreasing resistance values, multiple voltage shutdown channels with increasing or decreasing shutdown voltages, and multiple current shutdown channels with increasing or decreasing shutdown currents. The switching of these channels can be achieved through switching devices (such as single-connected multi-control switches) or switching circuits.

[0061] It should also be noted that when the shutdown channel module switches channels based on a channel switching signal, it can execute a switch each time it receives a signal, cyclically switching between multiple channels. If a single switch is not sufficient to suppress the voltage stress of the power module and further switching is required, the isolation driver module generates another channel switching signal after real-time sampling feedback from the voltage sampling module or the current sampling module to switch to the next shutdown channel, thus achieving multi-channel switching.

[0062] The power module driving circuit provided in this embodiment samples the bus voltage of the power module through a voltage sampling module and the current flowing through the power module through a current sampling module. The isolation driving module then performs logical processing based on the voltage sampling signal and the current sampling signal and outputs a channel switching signal, so that the shutdown channel module switches between multiple shutdown channels with different performances provided between the isolation driving module and the power module according to the channel switching signal to drive the power module to shut down, thereby achieving the purpose of avoiding overstress of the power module. In this circuit, the power module driving circuit itself samples the voltage and current, and no additional external detection circuit is required, which can avoid excessive cost increase. In this case, the shutdown channel switching is also achieved through the integrated isolation driving module, which can quickly achieve sampling and reduce switching delay, thereby timely and effectively suppressing the shutdown stress of the power module, achieving the effect of suppressing the voltage stress of the power module without increasing or significantly increasing the shutdown loss of the power module.

[0063] In one possible embodiment, referring to Figure 2 In the power module driving circuit, the isolation driving module includes an overvoltage protection unit, an overcurrent protection unit and a logic switching unit.

[0064] Among them, the overvoltage protection unit is connected to the voltage sampling module, the overcurrent protection unit is connected to the current sampling module, and the logic switching unit is connected to the overvoltage protection unit and the overcurrent protection unit respectively;

[0065] The overvoltage protection unit is used to compare the voltage sampling signal with the preset voltage signal and output an overvoltage protection signal;

[0066] The overcurrent protection unit is used to compare the current sampling signal with the preset current signal and output an overcurrent protection signal;

[0067] The logic switching unit is used to perform logic OR processing according to the overvoltage protection signal and the overcurrent protection signal, and output a corresponding channel switching signal.

[0068] It should be noted that both the preset voltage signal and the preset current signal can be set and adjusted by a variable resistor drive. A comparator is provided in the overvoltage protection unit, one input of which is connected to the voltage sampling module to receive the voltage sampling signal, and the other input is set to the overvoltage threshold through a variable resistor, corresponding to receiving the preset voltage signal, and then comparing the voltage sampling signal with the preset voltage signal. If the bus voltage of the power module is higher and exceeds the overvoltage threshold, the comparator flips, generates an overvoltage protection signal OV, and outputs it to the logic switching unit, so that the switching logic takes effect. Similarly, a comparator is also provided in the overcurrent protection unit, one input of which is connected to the current sampling module to receive the current sampling signal, and the other input is set to the overcurrent threshold through a variable resistor, corresponding to receiving the preset current signal, and then comparing the current sampling signal with the preset current signal. If the current flowing through the power module exceeds the overcurrent threshold, the comparator flips, generates an overcurrent protection signal OC, and outputs it to the logic switching unit, so that the switching logic takes effect. The logic switching unit performs logic OR processing, that is, when the overvoltage protection signal OV is received as a high level and / or the overcurrent protection signal OC is received as a high level, a channel switching signal can be generated accordingly to drive the shutdown channel module to perform channel switching.

[0069] In this embodiment, voltage sampling and current sampling are used to determine whether the power module is overstressed, and the power module is driven to shut down in time to ensure that the power module does not fail due to overstress, so that the power module can operate within the normal working range; an integrated isolation drive module is also used to implement logic processing functions for voltage protection and current protection, and the shutdown channel of the power module is switched to ensure that the shutdown operation of the power module does not generate excessive shutdown losses.

[0070] In one possible implementation, refer to Figure 2 In the power module driving circuit, the voltage sampling module includes a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R9 and a capacitor C1;

[0071] One end of the resistor R5 and the input end of the power module are both connected to the DC bus, the other end of the resistor R5 is connected to one end of the resistor R7 through the resistor R6, the other end of the resistor R7 is respectively connected to one end of the resistor R4 and one end of the resistor R9, the other end of the resistor R4 is respectively connected to one end of the capacitor C1 and the first end of the isolation drive module, and the other end of the capacitor C1, the other end of the resistor R9 and the first output end of the power module are all grounded.

[0072] Exemplarily, the power module may include an IGBT (Insulated Gate Bipolar Transistor), a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor), a JFET (Junction Field-Effect Transistor), or other power semiconductor switches (such as gallium nitride power semiconductors, silicon carbide power devices, etc.) and other controllable switching tubes, or a power switching circuit composed of multiple controllable switching tubes. The actual selection can be based on needs and is not specifically limited here.

[0073] In this embodiment, the power module is an IGBT tube as an example. Figure 2 The IGBT tube Q1 in the power module, the input end of the power module is the collector C of the IGBT tube Q1, and the collector C is connected to the DC bus Vbus ( Figure 2 (not shown), the first output end of the power module is the first emitter E1 of the IGBT tube Q1, and the first emitter E1 is grounded. One end of the resistor R5 is connected to the DC bus Vbus, and the other end of the resistor R4 is connected to the first end of the isolation driver module, specifically the voltage sampling end. In the voltage sampling module, the bus voltage of the DC bus Vbus is divided by resistors R5, R6, R7, and R9. The divided voltage is the sampling signal. After the sampling signal is filtered by the filter circuit composed of resistor R4 and capacitor C1, the filtered sampling signal, i.e., the voltage sampling signal, is input to the isolation driver module so that it can perform overvoltage protection accordingly.

[0074] In this embodiment, a voltage sampling module is directly added inside the driving circuit. The voltage sampling module samples the voltage of the power module through a simple resistor voltage division method. The circuit structure is simple and can save costs. It also utilizes the integrated current protection function of the isolation driving module of the power module driving circuit itself. Compared with the method of setting up an overvoltage detection circuit externally, the delay is short, which facilitates the isolation driving module to perform overvoltage protection in time and the shutdown channel module to respond in time to perform shutdown channel switching, thereby driving the power module to operate.

[0075] In one possible implementation, refer to Figure 2 ,In the power module driving circuit, the current sampling module includes a resistor R10, a resistor R11 and a capacitor C2;

[0076] One end of the resistor R10 is connected to the second output end of the power module and one end of the resistor R11 respectively, the other end of the resistor R10 is connected to one end of the capacitor C2 and the second end of the isolation drive module respectively, and the other end of the capacitor C2 and the other end of the resistor R11 are both grounded.

[0077] In this embodiment, Figure 2 As shown, the second output terminal of the power module is the second emitter E2 of the IGBT Q1, or the current sensing terminal of the power module. This second emitter E2 is grounded via a resistor R11 and is also connected to the second terminal of the isolation driver module, specifically the current sampling terminal, via a filter circuit consisting of a resistor R10 and a capacitor C2. In the current sampling module, the load current flows through resistor R11, generating a voltage drop, which generates a sampling signal. This sampling signal is filtered by the filter circuit consisting of resistor R10 and capacitor C2, and the filtered sampling signal, i.e., the current sampling signal, is input to the isolation driver module for corresponding overcurrent protection.

[0078] In this embodiment, a current sampling module is directly added inside the driving circuit. The current sampling module samples the current of the power module through a simple resistance sampling method. The circuit structure is simple and can save costs. It also utilizes the isolation driving module integrated current protection function of the power module driving circuit itself. Compared with the method of setting up an overcurrent detection circuit externally, the delay is short, which facilitates the isolation driving module to perform overcurrent protection in time and the shutdown channel module to respond in time to perform shutdown channel switching, thereby driving the power module to operate.

[0079] In a feasible implementation, the shutdown channels with different performances include shutdown resistance channels with different resistance values, voltage shutdown channels with different impedances, current shutdown channels with different currents, or negative pressure shutdown channels with different negative pressures.

[0080] It should be noted that the shutdown channel module can be a plurality of groups of shutdown resistors arranged outside the isolation drive module, and these plurality of groups of shutdown resistors form a plurality of shutdown resistor channels with different resistance values ​​between the isolation drive module and the power module; the shutdown channel module can also be arranged together with the isolation drive module in the same hardware module, and the shutdown channel module can be a channel composed of a plurality of groups of electronic circuits, such as a plurality of groups of voltage shutdown channels with different impedances, a plurality of groups of current shutdown channels with different currents, or a plurality of groups of negative pressure shutdown channels with different negative pressures.

[0081] In a specific embodiment, refer to Figure 2, in this power module driving circuit, the turn-off channel module includes a single-pole multi-control switch G1 and multiple turn-off resistors with different resistances;

[0082] One end of the switch G1 is a connection contact, which is connected to the output end of the isolation driving module. The other end of the switch G1 includes multiple control contacts, which are respectively connected to one end of multiple turn-off resistors correspondingly. The other ends of the multiple turn-off resistors are all connected to the control end of the power module;

[0083] The switch G1 is used to switch and connect any one of the multiple turn-off resistors according to the channel switching signal, so as to switch to the corresponding turn-off resistor channel.

[0084] In this embodiment, as Figure 2 shown, the turn-off channel module includes three turn-off resistors with different resistances, including turn-off resistor Roff1, turn-off resistor Roff2 and turn-off resistor Roff3;

[0085] The other end of the switch G1 includes three control contacts, which are respectively connected to one end of the turn-off resistor Roff1, one end of the turn-off resistor Roff2 and one end of the turn-off resistor Roff3 correspondingly. The other ends of the turn-off resistor Roff1, the turn-off resistor Roff2 and the turn-off resistor Roff3 are all connected to the control end of the power module, and are specifically connected to the gate G of the IGBT tube Q1.

[0086] Exemplarily, the resistances of the turn-off resistor Roff1, the turn-off resistor Roff2 and the turn-off resistor Roff3 increase in sequence, that is, Roff1 < Roff2 < Roff3. The isolation driving module outputs a channel switching signal to the turn-off channel module, indicating that the turn-off resistor switching logic takes effect. The control contact of the switch G1 can be switched and connected to the next turn-off channel, such as switching from the turn-off resistor Roff1 to the turn-off resistor Roff2. In practical applications, specific switching logics can also be set according to needs.

[0087] In this embodiment, multiple groups of turn-off resistors arranged outside the isolation driving module are used to form multiple turn-off resistor channels with different resistances. When there is overvoltage or overcurrent, it can be switched to a turn-off resistor channel with a larger resistance to achieve the suppression of the turn-off stress of the power module.

[0088] In another embodiment of the present application, referring to Figure 3 , Figure 3 is a connection schematic diagram of another embodiment of the power module driving circuit. The power module driving circuit further includes a temperature sampling module.

[0089] Among them, the temperature sampling module is arranged on the power module, and the isolation driving module is also connected to the temperature sampling module;

[0090] The temperature sampling module is used to sample the temperature of the power module and output a temperature sampling signal;

[0091] The isolation drive module is also used to perform logic processing according to the voltage sampling signal, the current sampling signal and the temperature sampling signal, and output a channel switching signal.

[0092] In one possible implementation, Figure 3 As shown, the temperature sampling module includes a thermistor NTC, a resistor R2 and a resistor R3;

[0093] One end of the thermistor NTC is respectively connected to one end of the resistor R2, one end of the resistor R3 and the third end of the isolation driver module, the other end of the resistor R2 is connected to the working power supply, and the other end of the resistor R3 and the other end of the thermistor NTC are both grounded.

[0094] In this embodiment, Figure 3 As shown, one end of the thermistor NTC is connected to the third end of the isolation driver module, specifically the temperature sampling end. In the temperature sampling module, the operating voltage VCC provided by the working power supply is divided by resistors R2 and R3. The divided voltage is the temperature sampling signal, which is input to the isolation driver module to enable corresponding overtemperature protection.

[0095] In a feasible implementation, the isolation driving module includes an overvoltage protection unit, an overcurrent protection unit, an overtemperature protection unit, and a logic switching unit.

[0096] Among them, the overvoltage protection unit is connected to the voltage sampling module, the overcurrent protection unit is connected to the current sampling module, the overtemperature protection unit is connected to the temperature sampling module, and the logic switching unit is connected to the overvoltage protection unit, the overcurrent protection unit and the overtemperature protection unit respectively;

[0097] The overvoltage protection unit is used to compare the voltage sampling signal with the preset voltage signal and output an overvoltage protection signal;

[0098] The overcurrent protection unit is used to compare the current sampling signal with the preset current signal and output an overcurrent protection signal;

[0099] The over-temperature protection unit is used to compare the temperature sampling signal with the preset threshold signal and output an over-temperature protection signal;

[0100] The logic switching unit is used to perform logic OR processing according to the overvoltage protection signal, the overcurrent protection signal and the overtemperature protection signal, and output the corresponding channel switching signal.

[0101] The preset threshold signal can be set and adjusted via a variable resistor drive. The voltage sampling signal, current sampling signal, and temperature sampling signal are all input to the isolation driver module, which can integrate overvoltage protection, overcurrent protection, and overtemperature protection functions.

[0102] In this embodiment, Figure 3 As shown, a comparator is provided in the over-temperature protection unit. One input end of the comparator is connected to the temperature sampling module to receive the temperature sampling signal, and the other input end sets the over-temperature threshold through a variable resistor, corresponding to receiving the preset threshold signal, and then compares the temperature sampling signal with the preset threshold signal. If the temperature of the power module is not within the over-temperature threshold, the comparator flips, generates an over-temperature protection signal OT and outputs it to the logic switching unit, so that the switching logic takes effect; the specific implementation of the overvoltage protection unit and the over-current protection unit can refer to the above, and will not be repeated here. The logic switching unit performs logical or processing, that is, when the over-voltage protection signal OV is received as a high level, the over-current protection signal OC is received as a high level and / or the over-temperature protection signal OT is received as a high level, a channel switching signal can be generated accordingly to drive the shutdown channel module to perform channel switching.

[0103] For example, for the power module being an IGBT tube Q1, when the temperature is low and not within the over-temperature threshold, the comparator flips, enabling the channel switching logic to take effect; for the power module being a silicon carbide MOS tube, when the temperature is high and not within the over-temperature threshold, the comparator flips, enabling the channel switching logic to take effect.

[0104] The power module drive circuit provided in this embodiment directly adds a temperature sampling module within the drive circuit. This temperature sampling module samples the power module temperature through a simple resistor sampling method, resulting in a simple circuit structure and cost savings. Furthermore, the power module drive circuit utilizes the integrated temperature protection function of the isolation drive module itself. Compared to the method of setting up an external over-temperature detection circuit, the delay is short, facilitating the timely over-temperature protection of the isolation drive module and the timely response of the shutdown channel module to switch the shutdown channel and drive the power module to operate. Simultaneously, voltage sampling, current sampling, and temperature sampling are used to determine whether the power module is overstressed, and the power module is promptly shut down to ensure that the power module does not fail due to overstress. Furthermore, the integrated isolation drive module implements logic processing functions for voltage protection, current protection, and temperature protection, switches the shutdown channel of the power module, and ensures that the shutdown operation of the power module does not generate excessive shutdown losses.

[0105] In another embodiment of the present application, referring to Figure 4 , Figure 4 This is a connection diagram of another embodiment of a power module driving circuit. The power module driving circuit further includes a short-circuit detection module.

[0106] The short-circuit detection module is connected to the power module, and the isolation drive module is also connected to the short-circuit detection module;

[0107] The short-circuit detection module is used to detect short circuits in the power module and output short-circuit detection signals;

[0108] The isolation drive module is also used to perform logic processing according to the voltage sampling signal, the current sampling signal and the short-circuit detection signal, and output a channel switching signal.

[0109] In one possible implementation, Figure 4 As shown, the short circuit detection module includes a diode D1, a resistor R1 and a capacitor C3;

[0110] The cathode of the diode D1 is connected to the input terminal of the power module, the anode of the diode D1 is connected to one end of the capacitor C3 and the fourth end of the isolation drive module through the resistor R1, and the other end of the capacitor C3 is grounded.

[0111] In this embodiment, Figure 4 As shown, the cathode of diode D1 is connected to the input terminal of the power module, specifically the collector C of IGBT tube Q1, and the anode of diode D1 is connected to the fourth terminal of the isolation driver module, specifically the short-circuit detection terminal, through resistor R1. Diode D1 is a high-voltage blocking diode, resistor R1 is a current-limiting resistor, and capacitor C3 is a desaturation (Desat) capacitor. In this short-circuit detection module, when the power module is turned on under normal working conditions, the voltage across the input and output terminals drops, diode D1 is turned on, and the voltage on capacitor C3 is small. At this time, the short-circuit detection signal input to the isolation driver module is low, indicating that there is no short circuit; when a short circuit occurs, the power module is turned on under the short-circuit state, the voltage across the input and output terminals rises, diode D1 is blocked, and the Desat internal current source or voltage source of the isolation driver module charges capacitor C3, and the voltage on capacitor C3 rises. At this time, the short-circuit detection signal input to the isolation driver module is high, indicating that there is a short circuit, and the isolation driver module can perform overload protection accordingly.

[0112] In a feasible implementation, the isolation driving module includes an overvoltage protection unit, an overcurrent protection unit, an overload protection unit, and a logic switching unit.

[0113] Among them, the overvoltage protection unit is connected to the voltage sampling module, the overcurrent protection unit is connected to the current sampling module, the overload protection unit is connected to the short circuit detection module, and the logic switching unit is connected to the overvoltage protection unit, the overcurrent protection unit and the overload protection unit respectively;

[0114] The overvoltage protection unit is used to compare the voltage sampling signal with the preset voltage signal and output an overvoltage protection signal;

[0115] The overcurrent protection unit is used to compare the current sampling signal with the preset current signal and output an overcurrent protection signal;

[0116] The overload protection unit is used to compare the short circuit detection signal with a preset reference signal and output an overload protection signal;

[0117] The logic switching unit is used to perform logic OR processing according to the overvoltage protection signal, the overcurrent protection signal and the overload protection signal, and output the corresponding channel switching signal.

[0118] The preset reference signal can be set and adjusted via a variable resistor drive. The voltage sampling signal, current sampling signal, and short-circuit detection signal are all input to the isolation driver module, which can integrate overvoltage protection, overcurrent protection, and overload protection functions.

[0119] In this embodiment, Figure 4 As shown, a comparator is provided in the overload protection unit, one input end of the comparator is connected to the short-circuit detection module to receive the short-circuit detection signal, and the other input end sets the comparator threshold through a variable resistor, corresponding to receiving a preset reference signal, and then compares the short-circuit detection signal with the preset reference signal. If the short-circuit detection signal exceeds the comparator threshold, the comparator flips, generates an overload protection signal OC1 and outputs it to the logic switching unit, so that the switching logic takes effect; the specific implementation of the overvoltage protection unit and the overcurrent protection unit can refer to the above, and will not be repeated here. The logic switching unit performs logical or processing, that is, when the overvoltage protection signal OV is received as a high level, the overcurrent protection signal OC is received as a high level and / or the overload protection signal OC1 is received as a high level, a channel switching signal can be generated accordingly to drive the shutdown channel module to perform channel switching.

[0120] For example, the power module is an IGBT tube Q1. When the IGBT tube Q1 is turned on under normal working conditions, the voltage VCE across its collector and emitter drops to a smaller voltage value Vcesat, for example, 1-3V, and the diode D1 is turned on. At this time, the voltage on the capacitor C3 is small, the short-circuit detection signal is low, and its voltage value does not exceed the comparator threshold, so the comparator does not flip; when a short circuit occurs in the power module and the IGBT tube Q1 is turned on under the short-circuit state, VCE rises and the diode D1 is blocked. At this time, the capacitor C3 is charged, the voltage on the capacitor C3 rises, the short-circuit detection signal is high, and its voltage value exceeds the comparator threshold. The comparator flips, making the channel switching logic effective. Optionally, the comparator threshold can be set to a lower threshold. If the load connected to the power module is short-circuited and the load current increases, when the IGBT tube Q1 is turned on under normal working conditions, VCE will increase slightly, and the voltage on capacitor C3 will rise accordingly. At this time, due to the low comparator threshold, the comparator will flip, and the channel switching logic will take effect. In this process, the comparator threshold can be regarded as a characteristic manifestation of the load saturation of the power module, which belongs to the current switching threshold of the variable resistor drive. It can be seen that the isolated drive module provides a quick overload protection function; afterwards, if the load current is significantly larger, VCE increases significantly, and the voltage on capacitor C3 is high, the comparator can also flip, and the channel switching logic will take effect.

[0121] The power module drive circuit provided in this embodiment directly adds a short-circuit detection module within the drive circuit. This short-circuit detection module detects short circuits in the power module or its load through high-voltage blocking of a diode. This results in a simple circuit structure and reduces costs. Furthermore, the power module drive circuit utilizes the isolation drive module's inherent overload protection function. Compared to the method of setting up an external short-circuit detection circuit, this method has a shorter delay, facilitating timely overload protection by the isolation drive module and timely response by the shutdown channel module to switch the shutdown channel and drive the power module. Furthermore, through voltage sampling, current sampling, and short-circuit detection, it is determined whether the power module is overstressed, and the power module is promptly shut down, ensuring that the power module does not fail due to overstress. Furthermore, the integrated isolation drive module implements logic processing functions for voltage protection, current protection, and overload protection, switches the shutdown channel of the power module, and ensures that the shutdown operation of the power module does not generate excessive shutdown losses.

[0122] In a specific application example, refer to Figure 5 , Figure 5 This is a connection diagram of a specific application example of a power module drive circuit. The power module drive circuit includes a power module, a voltage sampling module, a current sampling module, a temperature sampling module, a short circuit detection module, an isolation drive module and a shutdown channel module.

[0123] Among them, the isolation drive module includes an overvoltage protection unit, an overcurrent protection unit, an overtemperature protection unit, an overload protection unit and a logic switching unit. The logic switching unit can perform logic or processing according to the overvoltage protection signal, overcurrent protection signal, overtemperature protection signal and overload protection signal. If any of the above signals is a high level, it can correspond to the output channel switching signal to control the switching switch G1 in the shutdown channel module to switch to any one of the multiple shutdown resistors, thereby realizing channel switching between multiple shutdown channels.

[0124] It should be noted that for more implementation details of the power module drive circuit of this application example, please refer to the description of the specific implementation methods in the aforementioned embodiments. Correspondingly, the power module drive circuit of this application example also has all the beneficial effects brought about by the technical solutions of the aforementioned embodiments. For the sake of brevity, they are not further described here.

[0125] The above are only some embodiments of the present application and are not intended to limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A power module driving circuit, characterized in that: include: Power modules; A voltage sampling module is connected to the power module, and is used to sample the bus voltage of the power module and output a voltage sampling signal; a current sampling module connected to the power module, the current sampling module being used to sample the current flowing through the power module and output a current sampling signal; an isolation driving module, connected to the voltage sampling module and the current sampling module respectively, and configured to perform logic processing according to the voltage sampling signal and the current sampling signal and output a channel switching signal; A shutdown channel module is connected to the control end of the isolation drive module and the power module respectively. The shutdown channel module is used to provide multiple shutdown channels with different performances between the isolation drive module and the power module, and to switch channels between the multiple shutdown channels according to the channel switching signal to drive the power module to shut down.

2. The power module driving circuit according to claim 1, wherein: The isolation driver module includes: an overvoltage protection unit connected to the voltage sampling module, the overvoltage protection unit being configured to compare the voltage sampling signal with a preset voltage signal and output an overvoltage protection signal; an overcurrent protection unit connected to the current sampling module, the overcurrent protection unit being configured to compare the current sampling signal with a preset current signal and output an overcurrent protection signal; A logic switching unit is connected to the overvoltage protection unit and the overcurrent protection unit respectively, and is used to perform logic OR processing according to the overvoltage protection signal and the overcurrent protection signal, and output the channel switching signal accordingly.

3. The power module driving circuit according to claim 1, wherein: The voltage sampling module includes a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R9 and a capacitor C1; One end of the resistor R5 and the input end of the power module are both connected to the DC bus, the other end of the resistor R5 is connected to one end of the resistor R7 through the resistor R6, the other end of the resistor R7 is respectively connected to one end of the resistor R4 and one end of the resistor R9, the other end of the resistor R4 is respectively connected to one end of the capacitor C1 and the first end of the isolation drive module, and the other end of the capacitor C1, the other end of the resistor R9 and the first output end of the power module are all grounded.

4. The power module driving circuit according to claim 1, wherein: The current sampling module includes a resistor R10, a resistor R11 and a capacitor C2; One end of the resistor R10 is connected to the second output end of the power module and one end of the resistor R11 respectively, the other end of the resistor R10 is connected to one end of the capacitor C2 and the second end of the isolation driving module respectively, and the other end of the capacitor C2 and the other end of the resistor R11 are both grounded.

5. The power module driving circuit according to any one of claims 1 to 4, characterized in that: The shut-off channels with different performances include shut-off resistance channels with different resistance values, voltage shut-off channels with different impedances, current shut-off channels with different currents, or negative pressure shut-off channels with different negative pressures.

6. The power module driving circuit according to claim 5, wherein: The shutoff channel module includes a single-connected multi-control switch G1 and multiple shutoff resistors with different resistance values; One end of the switching switch G1 is a coupling contact connected to the output end of the isolation driving module, and the other end of the switching switch G1 includes a plurality of control contacts, each of which is connected to one end of a plurality of the shutdown resistors, and the other ends of the plurality of the shutdown resistors are connected to the control end of the power module; The switch G1 is used to switch to any one of the plurality of turn-off resistors according to the channel switching signal, so as to switch to the corresponding turn-off resistor channel.

7. The power module driving circuit according to claim 1, wherein: The power module driving circuit further includes: A temperature sampling module is provided on the power module, and is used to sample the temperature of the power module and output a temperature sampling signal; The isolation driving module is also connected to the temperature sampling module. The isolation driving module is further used to perform logic processing according to the voltage sampling signal, the current sampling signal and the temperature sampling signal, and output the channel switching signal.

8. The power module driving circuit according to claim 7, wherein: The isolation driver module includes: an overvoltage protection unit connected to the voltage sampling module, the overvoltage protection unit being configured to compare the voltage sampling signal with a preset voltage signal and output an overvoltage protection signal; an overcurrent protection unit connected to the current sampling module, the overcurrent protection unit being configured to compare the current sampling signal with a preset current signal and output an overcurrent protection signal; an over-temperature protection unit connected to the temperature sampling module, the over-temperature protection unit being configured to compare the temperature sampling signal with a preset threshold signal and output an over-temperature protection signal; A logic switching unit is connected to the overvoltage protection unit, the overcurrent protection unit and the overtemperature protection unit respectively. The logic switching unit is used to perform logic or processing according to the overvoltage protection signal, the overcurrent protection signal and the overtemperature protection signal, and output the channel switching signal accordingly.

9. The power module driving circuit according to claim 1, wherein: The power module driving circuit further includes: a short-circuit detection module connected to the power module, configured to detect a short circuit occurring in the power module and output a short-circuit detection signal; The isolation driving module is also connected to the short-circuit detection module. The isolation driving module is further configured to perform logic processing according to the voltage sampling signal, the current sampling signal and the short-circuit detection signal, and output the channel switching signal.

10. The power module driving circuit according to claim 9, wherein: The isolation driver module includes: an overvoltage protection unit connected to the voltage sampling module, the overvoltage protection unit being configured to compare the voltage sampling signal with a preset voltage signal and output an overvoltage protection signal; an overcurrent protection unit connected to the current sampling module, the overcurrent protection unit being configured to compare the current sampling signal with a preset current signal and output an overcurrent protection signal; an overload protection unit connected to the short-circuit detection module, the overload protection unit being configured to compare the short-circuit detection signal with a preset reference signal and output an overload protection signal; A logic switching unit is connected to the overvoltage protection unit, the overcurrent protection unit and the overload protection unit respectively, and the logic switching unit is used to perform logical OR processing according to the overvoltage protection signal, the overcurrent protection signal and the overload protection signal, and output the channel switching signal accordingly.

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