IGBT driving device and power supply circuit

Abstract

The utility model discloses an IGBT driving device and a power supply circuit, and relates to the technical field of driving control, an IGBT is connected between a power supply and a load, and the power supply and the load are electrically connected or disconnected; the IGBT driving device comprises a signal acquisition circuit, a main controller and a driving circuit, the signal acquisition circuit is electrically connected with a power supply input end, and the signal acquisition circuit is used for acquiring a power supply signal received by an IGBT and outputting a corresponding sampling signal; the input end of the main controller is electrically connected with the output end of the signal acquisition circuit, and the main controller is used for receiving the sampling signal and outputting a corresponding driving control signal according to the sampling signal; the input end of the driving circuit is electrically connected with the main controller, the output end of the driving circuit is electrically connected with the controlled end of the IGBT, and the driving circuit is used for outputting a driving voltage signal of the IGBT according to the driving control signal. The utility model aims to provide corresponding driving voltages for different IGBTs, and ensure reliable conduction and turn-off of the IGBTs, thereby improving the operational reliability of the IGBTs and prolonging the service life of the IGBTs.

Description

Technical Field

[0001] This application relates to the field of drive control technology, and in particular to an IGBT drive device and power supply circuit. Background Technology

[0002] In power electronic systems, IGBTs are widely used in various power conversion and control applications, such as motor drives, inverters, and uninterruptible power supplies (UPS), due to their advantages of high efficiency, high withstand voltage, and low conduction losses. However, the performance and reliability of IGBTs largely depend on the design of their drive circuits. The IGBT drive circuit is responsible for providing appropriate gate voltage and current to ensure reliable IGBT turn-on and turn-off. Because IGBTs of different brands, processes, and specifications have different electrical characteristics, using the same step drive voltage and conduction time for different IGBTs will result in different peak currents at the moment of turn-on. If the peak current is too large, it will cause IGBT damage and seriously affect the reliability of IGBT operation. Utility Model Content

[0003] The main purpose of this invention is to provide a driving device and power supply circuit for IGBTs, which aims to provide corresponding driving voltages for different IGBTs, ensure reliable IGBT turn-on and turn-off, thereby improving the operational reliability of IGBTs and extending their service life.

[0004] To achieve the above objectives, this utility model proposes an IGBT driving device, wherein the IGBT is connected between a power supply and a load, and switches the electrical connection between the power supply and the load on / off; the IGBT driving device includes:

[0005] The signal acquisition circuit is electrically connected to the power input terminal. The signal acquisition circuit is used to acquire the power signal received by the IGBT and output the corresponding sampling signal.

[0006] The main controller has its input terminal electrically connected to the output terminal of the signal acquisition circuit, and is used to receive the sampling signal and output a corresponding drive control signal according to the sampling signal;

[0007] The driving circuit has its input terminal electrically connected to the main controller and its output terminal electrically connected to the controlled terminal of the IGBT, and is used to output the driving voltage signal of the IGBT according to the driving control signal.

[0008] In one embodiment, the driving circuit includes:

[0009] The first-stage drive circuit is used to generate and output the drive signals required by the IGBT;

[0010] The second-stage drive circuit has its input terminal electrically connected to the output terminal of the first-stage drive circuit, its control terminal electrically connected to the output terminal of the main controller, and its output terminal connected to the controlled terminal of the IGBT. The second-stage drive circuit processes the drive signal output by the first-stage drive circuit according to the drive control signal from the main controller, and outputs the drive voltage signal for the IGBT.

[0011] In one embodiment, the second-stage driving circuit includes:

[0012] An amplifier circuit is provided, wherein the positive input terminal of the amplifier circuit is electrically connected to the main controller, and the negative input terminal of the amplifier circuit is grounded; the amplifier circuit is used to amplify the sampling signal connected to the positive input terminal and output the corresponding amplified signal.

[0013] A voltage regulation circuit is provided, wherein a first terminal of the voltage regulation circuit is electrically connected to the output terminal of the amplifier circuit, and a second terminal of the voltage regulation circuit is electrically connected to the IGBT; the voltage regulation circuit is used to receive the amplified signal output by the amplifier circuit, and output a drive voltage signal of the corresponding voltage level to the IGBT according to the amplified signal, so as to drive the IGBT to turn on / off the electrical connection between the power supply and the load.

[0014] In one embodiment, the voltage regulation circuit includes:

[0015] A current-limiting resistor, the first end of which is electrically connected to the output terminal of the first-stage drive circuit and the controlled terminal of the IGBT;

[0016] The transistor has its base electrically connected to the output terminal of the amplifier circuit, its emitter electrically connected to the second terminal of the current-limiting resistor, and its collector grounded.

[0017] In one embodiment, the amplification circuit includes:

[0018] An operational amplifier having a positive terminal, a negative terminal, and an amplification output terminal, wherein the amplification output terminal is electrically connected to the voltage regulation circuit.

[0019] A first resistor, the first end of which is electrically connected to the main controller, and the second end of which is electrically connected to the positive terminal of the operational amplifier;

[0020] The second resistor has its first end electrically connected to the negative terminal of the operational amplifier, and its second end grounded.

[0021] The feedback resistor, the first end of the feedback resistor, the first end of the second resistor, and the negative terminal are interconnected, and the second end of the feedback resistor is electrically connected to the amplified output terminal.

[0022] In one embodiment, the signal acquisition circuit includes:

[0023] A voltage acquisition circuit is electrically connected to the power input terminal. The voltage acquisition circuit is used to acquire the voltage signal output from the power input terminal to the IGBT and output the corresponding voltage sampling signal to the main controller.

[0024] And / or, a current acquisition circuit, which is electrically connected to the power input terminal, and is used to acquire the current signal output from the power input terminal to the IGBT, and output the corresponding current sampling signal to the main controller.

[0025] The main controller is used to output a corresponding drive control signal to the drive circuit according to the voltage sampling signal and / or the current sampling signal, so that the drive circuit outputs the drive voltage signal of the IGBT according to the drive control signal, and drives the IGBT to turn on / off the electrical connection between the power supply and the load.

[0026] In one embodiment, a capacitor is connected between the IGBT and the power supply, and the current acquisition circuit further includes:

[0027] A high-frequency current sampling circuit, wherein the first terminal of the high-frequency current sampling circuit is electrically connected to the power input terminal, and the second terminal of the high-frequency current sampling circuit is electrically connected to the input terminal of the capacitor;

[0028] The high-frequency current sampling circuit is used to collect the high-frequency current flowing through the IGBT and output the corresponding high-frequency current sampling signal to the main controller.

[0029] And / or, a low-frequency current sampling circuit, wherein the first terminal of the low-frequency current sampling circuit is electrically connected to the output terminal of the capacitor, and the second terminal of the low-frequency current sampling circuit is electrically connected to the IGBT;

[0030] The low-frequency current sampling circuit is used to collect the low-frequency current flowing through the IGBT and output the corresponding low-frequency current sampling signal to the main controller.

[0031] In one embodiment, the high-frequency current sampling circuit includes a high-frequency sampling resistor, which is connected in series between the power input terminal and the capacitor. The low-frequency current sampling circuit includes a low-frequency sampling resistor, which is connected in series between the capacitor and the IGBT.

[0032] In one embodiment, the driving device further includes:

[0033] An analog-to-digital converter (ADC) circuit is provided, wherein the input terminal of the ADC circuit is electrically connected to the output terminal of the signal acquisition circuit, and the output terminal of the ADC circuit is electrically connected to the main controller; the ADC circuit is used to convert the sampled signal into an analog-to-digital signal and output it to the main controller so that the main controller outputs a corresponding drive control signal.

[0034] In one embodiment, the driving device further includes:

[0035] The digital-to-analog converter circuit has its input terminal electrically connected to the main controller and its output terminal electrically connected to the second-stage drive circuit. The digital-to-analog converter circuit is used to convert the drive control signal output by the main controller into a digital signal and output it to the second-stage drive circuit, so that the second-stage drive circuit outputs a corresponding drive voltage signal to the IGBT.

[0036] This utility model proposes a power supply circuit, which includes the IGBT driving device described in any one of the above-mentioned claims, and

[0037] The power input terminal is used to connect the power supply to the load.

[0038] The power output terminal is used to connect the load.

[0039] The IGBT has a first terminal electrically connected to the power input terminal, a second terminal electrically connected to the power output terminal, and a controlled terminal electrically connected to the output terminal of the drive device. The IGBT is used to turn on / off the electrical connection between the power supply and the load.

[0040] The driving device is used to acquire the power signal at the first terminal of the IGBT to obtain a sampling signal, and output the driving voltage signal to the controlled terminal of the IGBT according to the sampling signal to control the IGBT to turn on / off.

[0041] This invention discloses an IGBT driving device, wherein the IGBT is connected between a power supply and a load, and conducts / disconnects the electrical connection between the power supply and the load; the IGBT driving device includes a signal acquisition circuit, a main controller, and a driving circuit. The signal acquisition circuit is electrically connected to the power input terminal and is used to acquire the power signal received by the IGBT and output a corresponding sampling signal; the input terminal of the main controller is electrically connected to the output terminal of the signal acquisition circuit and is used to receive the sampling signal and output a corresponding driving control signal according to the sampling signal; the input terminal of the driving circuit is electrically connected to the main controller, and the output terminal of the driving circuit is electrically connected to the controlled terminal of the IGBT and is used to output the driving voltage signal of the IGBT according to the driving control signal.

[0042] In practical applications, the main controller acquires the power signal received by the IGBT from the signal acquisition circuit and outputs a corresponding drive voltage control signal to control the drive circuit to output the corresponding drive voltage signal to the IGBT. That is, the IGBT drive device proposed in this application can determine the IGBT drive voltage based on the power signal, making the current of different IGBTs as consistent as possible during conduction. This improves the problem of excessive peak current causing IGBT damage during conduction, thereby enhancing the reliability of IGBT operation. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of a module of an embodiment of the IGBT driving device of this utility model;

[0045] Figure 2 This is a schematic diagram of another embodiment of the IGBT driving device of this utility model;

[0046] Figure 3 This is a schematic diagram of another embodiment of the IGBT driving device of this utility model;

[0047] Figure 4 This is a schematic diagram of another embodiment of the IGBT driving device of this utility model;

[0048] Figure 5 This is a schematic diagram illustrating the relationship between driving voltage and conduction current in an embodiment of a related technology;

[0049] Figure 6 This is a circuit diagram of an embodiment of the IGBT driving device of this utility model;

[0050] Figure 7 This is a schematic diagram of the driving voltage-conduction current relationship of an embodiment of the IGBT driving device of this utility model.

[0051] Figure 8 This is a detailed circuit diagram of an embodiment of the IGBT driving device of this utility model.

[0052] Explanation of icon numbers:

[0053] 10. Signal acquisition circuit; 20. Main controller; 30. Drive circuit; 31. First-stage drive circuit; 32. Second-stage drive circuit; 33. Amplifier circuit; 34. Voltage regulation circuit; 40. Analog-to-digital converter circuit; 50. Digital-to-analog converter circuit.

[0054] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0055] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0056] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0057] In power electronic systems, IGBTs are widely used in various power conversion and control applications, such as motor drives, inverters, and uninterruptible power supplies (UPS), due to their advantages of high efficiency, high withstand voltage, and low conduction losses. However, the performance and reliability of IGBTs largely depend on the design of their drive circuits. The IGBT drive circuit is responsible for providing appropriate gate voltage and current to ensure reliable turn-on and turn-off of the IGBT. Since IGBTs from different brands, with different manufacturing processes, and specifications have different electrical characteristics, refer to... Figure 5 If the same step drive voltage and conduction time are used for different IGBTs, the peak current of the IGBT at the moment of conduction will be different. If the peak current is too large, it will cause damage to the IGBT and seriously affect the reliability of IGBT operation.

[0058] Therefore, refer to Figure 1 This utility model proposes an IGBT driving device, wherein the IGBT is connected between a power supply and a load, and conducts / disconnects the electrical connection between the power supply and the load; the IGBT driving device includes:

[0059] The signal acquisition circuit 10 is electrically connected to the power input terminal. The signal acquisition circuit 10 is used to acquire the power signal received by the IGBT and output the corresponding sampling signal.

[0060] The main controller 20 has its input terminal electrically connected to the output terminal of the signal acquisition circuit 10, and is used to receive the sampling signal and output a corresponding drive control signal according to the sampling signal;

[0061] The driving circuit 30 has its input terminal electrically connected to the main controller and its output terminal electrically connected to the controlled terminal of the IGBT. It is used to output the driving voltage signal of the IGBT according to the driving control signal.

[0062] In this embodiment, the signal acquisition circuit 10 can be implemented using one or more of voltage sampling circuits and current sampling circuits. The sampled signals include voltage sampling signals and / or current sampling signals. The voltage sampling circuit includes resistive voltage divider circuits, operational amplifier circuits, etc., while the current sampling circuit includes shunt resistors, Hall effect sensors, current transformers, etc. The drive circuit 30 can be implemented using pulse transformer drive circuits, dedicated integrated drive chips, etc. The main controller 20 can be implemented using MCUs, DSPs (Digital Signal Processors), FPGAs (Field Programmable Gate Arrays), PLCs, SOCs (System on Chips), etc.

[0063] Taking the signal acquisition circuit 10, which includes a voltage sampling circuit and a current sampling circuit, as an example, the voltage sampling circuit is electrically connected to the power input terminal and is used to acquire the voltage signal output by the power supply, and output the corresponding voltage sampling signal to the main controller 20. The current sampling circuit can be connected in series in the loop containing the power supply, IGBT, and load, and is used to acquire the current flowing through the IGBT, and output the corresponding current sampling signal to the main controller 20. In this embodiment, since the IGBT's turn-on effect is different under different driving voltages, the power supply voltage (the voltage value corresponding to the voltage sampling signal) is acquired by the voltage sampling circuit. Then, the main controller 20 controls the drive circuit 30 to output the corresponding drive voltage according to the magnitude of the acquired voltage to drive the IGBT to work, reducing the peak current at the IGBT turn-on time, thereby improving reliability. In addition, under the same power supply voltage, the different load sizes will also affect the IGBT's turn-on degree. Therefore, the current in the loop containing the power supply, IGBT, and load is acquired by the current sampling circuit so that the main controller 20 controls the drive circuit 30 to output the corresponding drive voltage according to the current. In this way, different driving voltages can be provided to the IGBT based on the sampled signal, so that the driving voltage of the IGBT matches the current operating condition of the IGBT.

[0064] Optionally, based on the switching characteristics of the IGBT, the signal acquisition circuit 10 can acquire the current of the IGBT during the switching transient process, i.e., the high-frequency current. The main controller 20 adjusts the drive voltage according to the high-frequency current to ensure the safety of the IGBT during rapid switching. Optionally, the signal acquisition circuit 10 can also acquire the current of the IGBT under steady-state operating conditions, reflecting the load size, i.e., the low-frequency current. The main controller 20 adjusts the drive voltage according to the low-frequency current to ensure that the IGBT can operate stably under different load conditions. Optionally, the signal acquisition circuit 10 can acquire the power supply voltage. The main controller 20 adjusts the drive voltage according to the power supply voltage to ensure that the IGBT can reliably conduct under different power supply voltages, improving overvoltage and undervoltage problems. Optionally, the signal acquisition circuit 10 can also simultaneously acquire the power supply voltage, high-frequency current, and low-frequency current. The main controller 20 controls the drive circuit 30 to output the corresponding drive voltage based on the corresponding drive control signals of the three, so as to make the current of different IGBTs as consistent as possible when they are turned on, improving the problem of IGBT damage. It should be noted that the high-frequency current is positively correlated with the drive voltage, while the drive voltage is negatively correlated with the low-frequency current and the power supply voltage, respectively. The main controller 20 can determine the magnitude of the high-frequency current, low-frequency current and power supply voltage based on the sampling signal output by the signal acquisition circuit 10, so as to control the drive circuit 30 to output the corresponding drive voltage to the IGBT. For example, when the high-frequency current is large, the drive voltage should be increased, and when the low-frequency current and / or power supply voltage is large, the drive voltage should be decreased, thereby ensuring that the IGBT works safely and reliably under different operating conditions.

[0065] In practical applications, the main controller 20 outputs a drive control signal based on the sampled signal from the signal acquisition circuit 10, controlling the drive circuit 30 to output the corresponding drive voltage. This dynamically adjusts the IGBT's drive voltage, ensuring that the current changes during IGBT turn-on and turn-off remain within a safe range, reducing switching losses and extending the IGBT's lifespan. Furthermore, by simultaneously acquiring power supply voltage, low-frequency current, and high-frequency current, the main controller 20 can comprehensively consider multiple factors to ensure stable operation of the IGBT under different operating conditions, improving the reliability of IGBT operation.

[0066] In one embodiment, reference Figure 2 The driving circuit 30 includes:

[0067] The first-stage drive circuit 31 is used to generate and output the drive signals required by the IGBT;

[0068] The second-stage drive circuit 32 has its input terminal electrically connected to the output terminal of the first-stage drive circuit 31, its control terminal electrically connected to the output terminal of the main controller 20, and its output terminal connected to the controlled terminal of the IGBT. The second-stage drive circuit 32 is used to process the drive signal output by the first-stage drive circuit 31 according to the drive control signal of the main controller 20, and output the drive voltage signal of the IGBT.

[0069] It should be noted that, based on the switching characteristics of IGBTs and the requirements of practical applications, since the typical threshold voltage of many IGBTs is around 10V, the drive voltage should provide sufficient safety margin to ensure that the IGBT can be fully turned on under various operating conditions. At the same time, the drive voltage should also be compatible with most brands of IGBTs, exhibiting good compatibility. Therefore, in this embodiment, the drive voltage corresponding to the drive signal output by the first-stage drive circuit 31 can be 18V. Assuming the drive signal required by the IGBT is the original drive signal, the original drive signal output by the first-stage drive circuit 31 can be 18V. The main controller 20 outputs a drive control signal based on the sampling signal output by the signal acquisition circuit 10, to control the second-stage drive circuit 32 to process the original drive signal output by the first-stage drive circuit 31, such as increasing or decreasing it, thereby outputting a drive voltage signal to the IGBT, realizing dynamic adjustment of the IGBT drive voltage. This ensures the stability and safety of the IGBT under different operating conditions, while providing sufficient safety margin and good compatibility.

[0070] In practical applications, the first-stage drive circuit 31 can be the conventional drive circuit 30 of the IGBT in related technologies. In this application, a second-stage drive circuit 32 is added to the conventional drive circuit 30 as a voltage regulation circuit 34. Based on the sampling signals such as voltage, low-frequency current, and high-frequency current, the MCU dynamically adjusts the magnitude of the IGBT step drive voltage to reduce the peak current at the turn-on time of the IGBT, thereby improving the reliability of the IGBT operation.

[0071] Optionally, refer to Figure 3 The second-stage driving circuit 32 includes:

[0072] Amplifier circuit 33, the positive input terminal of which is electrically connected to the main controller 20, and the negative input terminal of which is grounded; the amplifier circuit 33 is used to amplify the sampling signal connected to the positive input terminal and output the corresponding amplified signal.

[0073] A voltage regulation circuit 34 is provided, with its first terminal electrically connected to the output terminal of the amplifier circuit 33 and its second terminal electrically connected to the IGBT. The voltage regulation circuit 34 is used to receive the amplified signal output by the amplifier circuit 33 and output a drive voltage signal of the corresponding voltage level to the IGBT according to the amplified signal, so as to drive the IGBT to turn on / off the electrical connection between the power supply and the load.

[0074] In this embodiment, the amplifier circuit 33 can be implemented using a common-emitter amplifier circuit 33, a common-source amplifier circuit 33, and an operational amplifier circuit, etc.; the voltage regulation circuit 34 can be implemented using a transistor, a step-up / step-down circuit, and the aforementioned main controller 20. Among these, since transistors have advantages such as high switching frequency, no sparking, high regulation accuracy, light weight, small size, long life, and high reliability, transistors can be used to implement the circuit.

[0075] Optionally, the voltage regulation circuit 34 includes:

[0076] A current-limiting resistor, the first end of which is electrically connected to the output terminal of the first-stage driving circuit 31 and the controlled terminal of the IGBT, respectively;

[0077] The transistor has its base electrically connected to the output terminal of the amplifier circuit 33, its emitter electrically connected to the second terminal of the current-limiting resistor, and its collector grounded.

[0078] The amplifier circuit 33 includes:

[0079] An operational amplifier having a positive terminal, a negative terminal, and an amplification output terminal, wherein the amplification output terminal is electrically connected to the voltage regulation circuit 34;

[0080] A first resistor, the first end of which is electrically connected to the main controller 20, and the second end of which is electrically connected to the positive terminal of the operational amplifier;

[0081] The second resistor has its first end electrically connected to the negative terminal of the operational amplifier, and its second end grounded.

[0082] The feedback resistor, the first end of the feedback resistor, the first end of the second resistor, and the negative terminal are interconnected, and the second end of the feedback resistor is electrically connected to the amplified output terminal.

[0083] Specifically, the first-stage driving circuit 31 provides an 18V driving voltage to the IGBT. The signal acquisition circuit 10 acquires the power signal received by the IGBT. The main controller 20, based on the sampling signal output by the signal acquisition circuit 10 (including but not limited to power supply voltage, low-frequency current and high-frequency current), controls the second-stage driving circuit 32 to adjust the 18V driving voltage output by the first-stage driving circuit 31 to output different step driving voltages to the IGBT.

[0084] refer to Figure 8 The MCU is the main controller 20, R1 is a current-limiting resistor, Q2 is a PNP transistor, Q1 is an IGBT, U1 is an operational amplifier, R2 is the first resistor, R3 is the second resistor, and R4 is the feedback resistor. The base of transistor Q2 is electrically connected to the positive terminal of the operational amplifier, the emitter of transistor Q2 is electrically connected to the current-limiting resistor R1, and the collector of transistor Q2 is grounded. When the main controller 20 receives the sampling signal, it outputs the corresponding voltage signal (drive control signal) to the operational amplifier U1. After being amplified by the operational amplifier, it is output to the base of transistor Q2. When the base voltage is lower than the 18V output by the first-stage drive circuit 31, transistor Q2 conducts, and the voltage signal output by the main controller 20 directly drives the IGBT. It should be noted that the voltage signal output by the main controller 20 to the base changes with the sampling signal. If the voltage signal output by the main controller 20 is different, the base voltage of transistor Q2 will also be different. Figure 7 The IGBT driving device proposed in this application can dynamically adjust the magnitude of the stepped driving voltage output from the driving circuit 30 to the IGBT based on the sampled signal, thereby enabling IGBTs of different specifications to have the same on-state current and improving the IGBT overcurrent problem. When the base voltage is low (below 18V), the voltage difference V between the base and emitter is... be It is relatively small, but still sufficient to turn on the PNP transistor. Because V be The base current I is relatively small, but still within the conduction range. b It will be relatively large. According to Ic =βI b From I, we can obtain the collector current I. c It will also be relatively large. That is, the voltage drop V between the collector and emitter. ce The voltage drop V between the collector and emitter is relatively small, resulting in a higher conduction degree for the PNP transistor. Therefore, when the PNP transistor has a high conduction degree, the voltage drop V between the collector and emitter is relatively small. ce The voltage difference is relatively small, which means the drive voltage (i.e., step voltage) output to the IGBT is low. Similarly, when the base voltage is relatively high (still below 18V), the voltage difference V between the base and emitter is relatively small. be Larger, because V be Larger base current I b It will be smaller. According to I c =βI b Therefore, the collector current I is obtained. c It will also be relatively small. That is, the voltage drop V between the collector and emitter. ce The voltage drop V between the collector and emitter is relatively large, resulting in a relatively low conduction level for the PNP transistor. Therefore, when the conduction level of the PNP transistor is low, the voltage drop V between the collector and emitter is relatively large. ce A relatively large voltage level means that the drive voltage (i.e., step voltage) output to the IGBT is relatively high. When the base voltage equals the voltage output by the first-stage drive circuit 31 (e.g., 18V), the PNP transistor is cut off, and the IGBT is directly driven by the first-stage drive circuit 31. Therefore, the second-stage drive circuit 32 can adjust the magnitude of the drive voltage output to the IGBT according to the drive control signal output by the main controller 20, thereby ensuring that the current value of IGBTs of different specifications tends to be consistent when they are turned on, avoiding damage to the IGBT due to excessive peak current, and thus improving the reliability of IGBT operation.

[0085] It should be noted that the current-limiting resistor R1 limits the emitter current of Q2 to prevent excessive emitter current from causing the PNP to overheat. The first resistor R2 limits the current from the main controller 20 output to the positive terminal of the operational amplifier, preventing excessive input current at the positive terminal from damaging the operational amplifier. The second resistor R3 limits the current from the main controller 20 output to the negative terminal of the operational amplifier, forming a balanced input circuit together with the first resistor R2 to ensure a balanced input signal for the operational amplifier and improve the accuracy of the operational amplifier's output signal. The feedback resistor R4 is used to stabilize the output voltage of the operational amplifier, reduce output voltage fluctuations, and improve the stability of the operational amplifier's output signal.

[0086] In practical applications, the main controller 20 dynamically adjusts the drive voltage output by the drive circuit 30 based on sampling signals such as power supply voltage, low-frequency current, and high-frequency current acquired by the signal processing circuit, ensuring reliable turn-on and turn-off of the IGBT under different operating conditions. Furthermore, negative feedback is provided through operational amplifiers and feedback resistors, stabilizing the operational amplifier output voltage, reducing output voltage fluctuations, and thus improving the stability of the drive voltage. The current-limiting resistor prevents overcurrent from causing overheating of the PNP transistor and IGBT, improving the reliability of the transistor and IGBT operation and extending their service life.

[0087] In one embodiment, the signal acquisition circuit 10 includes:

[0088] A voltage acquisition circuit is electrically connected to the power input terminal. The voltage acquisition circuit is used to acquire the voltage signal output from the power input terminal to the IGBT and output the corresponding voltage sampling signal to the main controller.

[0089] And / or, a current acquisition circuit, which is electrically connected to the power input terminal, is used to acquire the current signal output from the power input terminal to the IGBT, and output the corresponding current sampling signal to the main controller 20.

[0090] The main controller 20 is used to output a corresponding drive control signal to the drive circuit 30 according to the voltage sampling signal and / or the current sampling signal, so that the drive circuit 30 outputs the drive voltage signal of the IGBT according to the drive control signal, and drives the IGBT to turn on / off the electrical connection between the power supply and the load.

[0091] In this embodiment, the voltage acquisition circuit can be implemented using a resistive voltage divider circuit, an operational amplifier circuit, etc., and the current sampling circuit can be implemented using a shunt resistor, a Hall effect sensor, a current transformer, etc.

[0092] Specifically, the voltage sampling circuit is electrically connected to the power input terminal to collect the voltage signal output by the power supply and outputs the corresponding voltage sampling signal to the main controller 20. The main controller 20 controls the drive circuit 30 to output the corresponding drive voltage based on the magnitude of the collected voltage to drive the IGBT, thereby reducing the peak current at the IGBT turn-on time and improving reliability. The current sampling circuit can be connected in series in the circuit containing the power supply and the IGBT to collect the current flowing through the IGBT and output the corresponding current sampling signal to the main controller 20. That is, the current sampling circuit collects the current in the circuit containing the power supply, IGBT, and load, so that the main controller 20 controls the drive circuit 30 to output the corresponding drive voltage based on the current. In this way, different magnitudes of drive voltage are provided to the IGBT based on the sampled signal, so that the drive voltage of the IGBT matches the current operating condition of the IGBT.

[0093] It should be noted that since the impedance of a capacitor is inversely proportional to its frequency, high-frequency signals encounter lower impedance when passing through a capacitor, while low-frequency signals encounter higher impedance. Therefore, low-frequency signals face greater resistance when passing through a capacitor, with most of their energy being stored rather than transferred through the capacitor. High-frequency signals encounter less resistance, and most of their energy is transferred through the capacitor. In this embodiment, the frequency response characteristics of the capacitor are used to distinguish between high-frequency and low-frequency currents to complete the acquisition of both.

[0094] In this embodiment, a capacitor is connected between the IGBT and the power supply, and the current acquisition circuit further includes:

[0095] A high-frequency current sampling circuit, wherein the first terminal of the high-frequency current sampling circuit is electrically connected to the power input terminal, and the second terminal of the high-frequency current sampling circuit is electrically connected to the input terminal of the capacitor;

[0096] The high-frequency current sampling circuit is used to collect the high-frequency current flowing through the IGBT and output the corresponding high-frequency current sampling signal to the main controller.

[0097] And / or, a low-frequency current sampling circuit, wherein the first terminal of the low-frequency current sampling circuit is electrically connected to the output terminal of the capacitor, and the second terminal of the low-frequency current sampling circuit is electrically connected to the IGBT;

[0098] The low-frequency current sampling circuit is used to collect the low-frequency current flowing through the IGBT and output the corresponding low-frequency current sampling signal to the main controller.

[0099] The high-frequency current sampling circuit includes a high-frequency sampling resistor, which is connected in series between the power input terminal and the capacitor. The low-frequency current sampling circuit includes a low-frequency sampling resistor, which is connected in series between the capacitor and the IGBT.

[0100] In this embodiment, reference Figure 6 The high-frequency current sampling circuit uses a high-frequency sampling resistor, while the low-frequency current sampling circuit uses a low-frequency sampling resistor. The power input terminal includes the positive and negative terminals. The first terminal of the capacitor is connected to the positive terminal of the power supply, and the second terminal of the capacitor is connected to the negative terminal of the power supply. The low-frequency sampling resistor is connected in series between the power supply and the capacitor, and the high-frequency sampling resistor is connected in series between the capacitor and the emitter of the IGBT.

[0101] In accordance with the above embodiments, the voltage sampling circuit is electrically connected to the power input terminal to collect the voltage signal output by the power supply and output a corresponding voltage sampling signal to the main controller 20. The main controller 20 controls the drive circuit 30 to output a corresponding drive voltage based on the magnitude of the collected voltage to drive the IGBT, thereby reducing the peak current at the IGBT turn-on time and improving reliability. Simultaneously, the main controller 20 may also include a second voltage detection circuit and a third voltage detection circuit. The second voltage detection circuit detects the voltage across the low-frequency sampling resistor and outputs a low-frequency sampling signal, enabling the main controller 20 to determine the low-frequency current output by the power supply based on the low-frequency sampling signal and control the drive circuit 30 to output a corresponding drive voltage to the IGBT based on the low-frequency current. Furthermore, the third voltage detection circuit detects the voltage across the high-frequency sampling resistor and outputs a high-frequency sampling signal, enabling the main controller 20 to determine the high-frequency current in the IGBT circuit based on the high-frequency sampling signal and control the drive circuit 30 to output a corresponding drive voltage to the IGBT based on the high-frequency current. To further improve the reliability and stability of IGBT operation, in this embodiment, the power supply voltage, high-frequency current, and low-frequency current are detected so that the main controller 20 outputs corresponding drive control signals according to the power supply voltage, high-frequency current, and low-frequency current. That is, the main controller 20 turns on the step drive signal of the IGBT, thereby dynamically adjusting the step drive voltage output by the drive circuit 30 to the IGBT.

[0102] Specifically, the high-frequency sampling resistor can collect the current of the IGBT during the switching transient process, i.e., the high-frequency current. The main controller 20 adjusts the drive voltage based on the high-frequency current to ensure the safety of the IGBT during rapid switching. The low-frequency sampling resistor can collect the current of the IGBT under steady-state operating conditions, reflecting the load size, i.e., the low-frequency current. The main controller 20 adjusts the drive voltage based on the low-frequency current to ensure stable operation of the IGBT under different load conditions. In practical applications, the main controller 20 controls the drive circuit 30 to output corresponding drive voltages based on the corresponding drive control signals from these three components. This ensures that the current of different IGBTs during conduction is as consistent as possible, thereby mitigating the problem of IGBT damage.

[0103] It should be noted that the high-frequency current is positively correlated with the driving voltage, while the driving voltage is negatively correlated with both the low-frequency current and the power supply voltage. The main controller 20 can determine the power supply voltage based on the voltage sampling signal output by the voltage detection circuit, determine the high-frequency current based on the high-frequency sampling resistor and the high-frequency sampling signal output by the third voltage detection circuit, and determine the low-frequency current based on the low-frequency sampling resistor and the low-frequency sampling signal output by the second voltage detection circuit. Based on the magnitude of the high-frequency current, low-frequency current, and power supply voltage, the controller controls the driving circuit 30 to output the corresponding driving voltage to the IGBT. For example, when the high-frequency current is large, the driving voltage should be increased; when the low-frequency current and / or power supply voltage is large, the driving voltage should be decreased, thereby ensuring that the IGBT operates safely and reliably under different operating conditions.

[0104] The high-frequency sampling resistor enables current acquisition during the IGBT's switching transient process, allowing the main controller 20 to adjust the drive voltage based on the high-frequency current. This ensures the IGBT's safety during rapid switching, reduces peak current, and prevents damage caused by excessive thermal stress. The low-frequency sampling resistor enables current acquisition under steady-state operating conditions, allowing the main controller 20 to adjust the drive voltage based on the low-frequency current. This ensures stable operation of the IGBT under different load conditions, improving its applicability. In this embodiment, the IGBT drive device achieves dynamic adjustment of the IGBT drive voltage through the coordinated operation of the voltage and current acquisition circuits, ensuring stable and safe operation of the IGBT under various conditions and improving its reliability.

[0105] It should be noted that, in order to achieve precise processing of the sampled signal and precise control of the drive voltage, reference... Figure 4 and Figure 8 The driving device further includes:

[0106] The analog-to-digital converter circuit 40 has its input terminal electrically connected to the output terminal of the signal acquisition circuit 10, and its output terminal electrically connected to the main controller 20. The analog-to-digital converter circuit 40 is used to convert the sampled signal into an analog signal and output it to the main controller 20, so that the main controller 20 outputs a corresponding drive control signal.

[0107] The drive device further includes:

[0108] The digital-to-analog converter circuit 50 has its input terminal electrically connected to the main controller 20 and its output terminal electrically connected to the second-stage drive circuit 32. The digital-to-analog converter circuit 50 is used to convert the drive control signal output by the main controller 20 into a digital signal and output it to the second-stage drive circuit 32, so that the second-stage drive circuit 32 outputs a corresponding drive voltage signal to the IGBT.

[0109] In this embodiment, the analog-to-digital converter circuit 40 can be implemented using a successive approximation analog-to-digital converter (A / D converter), an integrating analog-to-digital converter, a serial-parallel comparison analog-to-digital converter, etc., and the digital-to-analog converter circuit 50 can be implemented using a successive approximation digital-to-analog converter (D / A converter), an integrating digital-to-analog converter, a serial-parallel comparison digital-to-analog converter, etc.

[0110] Specifically, the sampling signal is an analog signal. The analog-to-digital converter (ADC) 40 converts the analog signal into a digital signal and outputs it to the main controller 20. The main controller 20 processes the digital signal to determine the power supply voltage and / or high-frequency current and / or low-frequency current corresponding to the sampling signal, and then outputs the corresponding drive control signal to the drive circuit 30 to achieve dynamic adjustment of the IGBT drive voltage. It can be understood that the digital-to-analog converter (DAC) 50 can convert the digital signal output by the main controller 20 into an analog signal and control the drive circuit 30 to output the corresponding drive voltage according to the analog signal. In conjunction with the above embodiment, the voltage sampling circuit collects the voltage signal output by the power supply and outputs the corresponding voltage sampling signal to the ADC 40. The main controller 20 processes the first digital signal output by the ADC 40 and outputs the corresponding drive control signal to the DAC 50. The DAC 50 converts the digital drive control signal into an analog signal and outputs it to the drive circuit 30, controlling the drive circuit 30 to output the corresponding drive voltage to drive the IGBT. Simultaneously, the second voltage detection circuit detects the voltage across the low-frequency sampling resistor and outputs a low-frequency sampling signal to the analog-to-digital converter circuit 40. This allows the main controller 20 to process the second digital signal output by the analog-to-digital converter circuit 40 and output a corresponding drive control signal to the digital-to-analog converter circuit 50. The drive control signal, which is a digital signal, is converted into an analog signal and output to the drive circuit 30, controlling the drive circuit 30 to output the corresponding drive voltage to the IGBT. Furthermore, the third voltage detection circuit detects the voltage across the high-frequency sampling resistor and outputs a high-frequency sampling signal to the analog-to-digital converter circuit 40. This allows the main controller 20 to process the third digital signal output by the analog-to-digital converter circuit 40 and output a corresponding drive control signal to the digital-to-analog converter circuit 50. The drive control signal, which is a digital signal, is converted into an analog signal and output to the drive circuit 30, controlling the drive circuit 30 to output the corresponding drive voltage. When power supply voltage, low-frequency current and high-frequency current are collected simultaneously, the sampling signals output by the corresponding signal processing circuit can be output to the same or different analog-to-digital conversion circuits 40 for analog-to-digital conversion, and the corresponding digital signals can be output to the main controller 20. This allows the main controller 20 to determine the power supply voltage, low-frequency current and high-frequency current based on the digital signals, and output the corresponding drive control signals to dynamically adjust the step drive voltage output by the drive circuit 30 to the IGBT.

[0111] It should be noted that both the analog-to-digital converter circuit 40 and the digital-to-analog converter circuit 50 can be integrated with the main controller 20 to reduce wiring area.

[0112] In practical applications, the analog-to-digital converter (ADC) 40 ensures that the main controller 20 can accurately acquire the values ​​of power supply voltage, low-frequency current, and high-frequency current. Furthermore, the ADC 40 filters out noise in the analog signal, improves the signal-to-noise ratio, ensures the accuracy of the sampled signal, and ensures that the main controller 20 outputs a precise drive control signal, thereby achieving precise control of the drive voltage. The digital-to-analog converter (DAC) 50 ensures that the main controller 20 can precisely control the drive voltage output by the drive circuit 30, enabling the IGBT to operate stably under different operating conditions. In addition, the DAC 50 can output a smooth analog signal, avoiding sudden changes in the drive voltage, reducing the impact on the IGBT during switching, and thus improving the IGBT's lifespan. Therefore, by introducing the ADC 40 and DAC 50, the IGBT drive device can achieve precise processing of the sampled signal and precise control of the drive voltage. This ensures that the IGBT can operate stably and safely under different operating conditions, thereby improving the overall performance of the power supply circuit in which the IGBT is located.

[0113] This utility model also proposes a power supply circuit, which includes the aforementioned IGBT driving device, and

[0114] The power input terminal is used to connect the power supply to the load.

[0115] The power output terminal is used to connect the load.

[0116] The IGBT has a first terminal electrically connected to the power input terminal, a second terminal electrically connected to the power output terminal, and a controlled terminal electrically connected to the output terminal of the drive device. The IGBT is used to turn on / off the electrical connection between the power supply and the load.

[0117] The driving device is used to acquire the power signal at the first terminal of the IGBT to obtain a sampling signal, and output the driving voltage signal to the controlled terminal of the IGBT according to the sampling signal to control the IGBT to turn on / off.

[0118] In this embodiment, the aforementioned driving device collects the power supply voltage and / or low-frequency current and / or high-frequency current output by the power supply, and after obtaining the sampled signal, outputs a corresponding driving voltage signal to the IGBT to control the operating state of the IGBT. In this way, the IGBT driving device can dynamically adjust the IGBT driving voltage based on the sampled signal, ensuring that the current change during IGBT turn-on and turn-off is within a safe range, reducing switching losses, extending the IGBT's lifespan, and thus improving the reliability and stability of the power supply circuit.

[0119] It is worth noting that since the power supply circuit of this application includes the aforementioned IGBT driving device, the embodiments of the power supply circuit of this application include all the technical solutions of all embodiments of the aforementioned IGBT driving device, and the technical effects achieved are exactly the same, so they will not be repeated here.

[0120] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields are included within the scope of the present utility model.

Claims

1. A driving device for an IGBT, characterized in that, The IGBT is connected between the power supply and the load, and conducts / disconnects the electrical connection between the power supply and the load; The IGBT driving device includes: The signal acquisition circuit is electrically connected to the power input terminal. The signal acquisition circuit is used to acquire the power signal received by the IGBT and output the corresponding sampling signal. The main controller has its input terminal electrically connected to the output terminal of the signal acquisition circuit, and is used to receive the sampling signal and output a corresponding drive control signal according to the sampling signal; The driving circuit has its input terminal electrically connected to the main controller and its output terminal electrically connected to the controlled terminal of the IGBT, and is used to output the driving voltage signal of the IGBT according to the driving control signal.

2. The IGBT driving device as described in claim 1, characterized in that, The driving circuit includes: The first-stage drive circuit is used to generate and output the drive signals required by the IGBT; The second-stage drive circuit has its input terminal electrically connected to the output terminal of the first-stage drive circuit, its control terminal electrically connected to the output terminal of the main controller, and its output terminal connected to the controlled terminal of the IGBT. The second-stage drive circuit processes the drive signal output by the first-stage drive circuit according to the drive control signal from the main controller, and outputs the drive voltage signal for the IGBT.

3. The IGBT driving device as described in claim 2, characterized in that, The second-stage driving circuit includes: An amplifier circuit is provided, wherein the positive input terminal of the amplifier circuit is electrically connected to the main controller, and the negative input terminal of the amplifier circuit is grounded; the amplifier circuit is used to amplify the sampling signal connected to the positive input terminal and output the corresponding amplified signal. A voltage regulation circuit is provided, wherein a first terminal of the voltage regulation circuit is electrically connected to the output terminal of the amplifier circuit, and a second terminal of the voltage regulation circuit is electrically connected to the IGBT; the voltage regulation circuit is used to receive the amplified signal output by the amplifier circuit, and output a drive voltage signal of the corresponding voltage level to the IGBT according to the amplified signal, so as to drive the IGBT to turn on / off the electrical connection between the power supply and the load.

4. The IGBT driving device as described in claim 3, characterized in that, The voltage regulation circuit includes: A current-limiting resistor, the first end of which is electrically connected to the output terminal of the first-stage drive circuit and the controlled terminal of the IGBT; The transistor has its base electrically connected to the output terminal of the amplifier circuit, its emitter electrically connected to the second terminal of the current-limiting resistor, and its collector grounded.

5. The IGBT driving device as described in claim 3, characterized in that, The amplifier circuit includes: An operational amplifier having a positive terminal, a negative terminal, and an amplification output terminal, wherein the amplification output terminal is electrically connected to the voltage regulation circuit. A first resistor, the first end of which is electrically connected to the main controller, and the second end of which is electrically connected to the positive terminal of the operational amplifier; The second resistor has its first end electrically connected to the negative terminal of the operational amplifier, and its second end grounded. The feedback resistor, the first end of the feedback resistor, the first end of the second resistor, and the negative terminal are interconnected, and the second end of the feedback resistor is electrically connected to the amplified output terminal.

6. The IGBT driving device as described in claim 1, characterized in that, The signal acquisition circuit includes: A voltage acquisition circuit is electrically connected to the power input terminal. The voltage acquisition circuit is used to acquire the voltage signal output from the power input terminal to the IGBT and output the corresponding voltage sampling signal to the main controller. And / or, a current acquisition circuit, which is electrically connected to the power input terminal, and is used to acquire the current signal output from the power input terminal to the IGBT, and output the corresponding current sampling signal to the main controller. The main controller is used to output a corresponding drive control signal to the drive circuit according to the voltage sampling signal and / or the current sampling signal, so that the drive circuit outputs the drive voltage signal of the IGBT according to the drive control signal, and drives the IGBT to turn on / off the electrical connection between the power supply and the load.

7. The IGBT driving device as described in claim 6, characterized in that, A capacitor is connected between the IGBT and the power supply, and the current acquisition circuit further includes: A high-frequency current sampling circuit, wherein the first terminal of the high-frequency current sampling circuit is electrically connected to the power input terminal, and the second terminal of the high-frequency current sampling circuit is electrically connected to the input terminal of the capacitor; The high-frequency current sampling circuit is used to collect the high-frequency current flowing through the IGBT and output the corresponding high-frequency current sampling signal to the main controller. And / or, a low-frequency current sampling circuit, wherein the first terminal of the low-frequency current sampling circuit is electrically connected to the output terminal of the capacitor, and the second terminal of the low-frequency current sampling circuit is electrically connected to the IGBT; The low-frequency current sampling circuit is used to collect the low-frequency current flowing through the IGBT and output the corresponding low-frequency current sampling signal to the main controller.

8. The IGBT driving device as described in claim 7, characterized in that, The high-frequency current sampling circuit includes a high-frequency sampling resistor, which is connected in series between the power input terminal and the capacitor. The low-frequency current sampling circuit includes a low-frequency sampling resistor, which is connected in series between the capacitor and the IGBT.

9. The IGBT driving device as described in claim 2, characterized in that, The drive device further includes: An analog-to-digital converter (ADC) circuit is provided, wherein the input terminal of the ADC circuit is electrically connected to the output terminal of the signal acquisition circuit, and the output terminal of the ADC circuit is electrically connected to the main controller; the ADC circuit is used to convert the sampled signal into an analog-to-digital signal and output it to the main controller so that the main controller outputs a corresponding drive control signal.

10. The IGBT driving device as described in claim 2, characterized in that, The drive device further includes: The digital-to-analog converter circuit has its input terminal electrically connected to the main controller and its output terminal electrically connected to the second-stage drive circuit. The digital-to-analog converter circuit is used to convert the drive control signal output by the main controller into a digital signal and output it to the second-stage drive circuit, so that the second-stage drive circuit outputs a corresponding drive voltage signal to the IGBT.

11. A power supply circuit, characterized in that, The power supply circuit includes a driving device for the IGBT as described in any one of claims 1 to 10, and The power input terminal is used to connect the power supply to the load. The power output terminal is used to connect the load. The IGBT has a first terminal electrically connected to the power input terminal, a second terminal electrically connected to the power output terminal, and a controlled terminal electrically connected to the output terminal of the drive device. The IGBT is used to turn on / off the electrical connection between the power supply and the load. The driving device is used to acquire the power signal at the first terminal of the IGBT to obtain a sampling signal, and output the driving voltage signal to the controlled terminal of the IGBT according to the sampling signal to control the IGBT to turn on / off.

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