IGBT overcurrent protection circuit and ultrasonic power supply

Abstract

The utility model relates to the technical field of circuits, and discloses an IGBT overcurrent protection circuit and an ultrasonic power supply. The IGBT overcurrent protection circuit comprises a control circuit and at least two current detection circuits. The current detection circuits are respectively connected with the corresponding IGBT devices and are used for collecting the current of the IGBT devices and generating corresponding detection signals when the current of the IGBT devices exceeds a preset current threshold value; the control circuit is connected with each current detection circuit and each IGBT device, and is used for driving each IGBT device to be powered off and turned off when receiving a detection signal generated by at least one current detection circuit. According to the embodiment of the invention, synchronous over-current protection can be carried out on a plurality of IGBT devices, and over-current damage to the IGBT devices is avoided.

Description

Technical Field

[0001] This application relates to the field of circuit technology, and in particular to an IGBT overcurrent protection circuit and an ultrasonic power supply. Background Technology

[0002] Due to their advantages in frequency, current, and voltage operating range, IGBTs occupy an important position in the fields of power conversion and automatic control, becoming the core component of power conversion products. In IGBT applications, overcurrent protection is a crucial technology. Overcurrent protection circuits not only affect the operating performance and safety of the IGBT itself, but also impact the performance and safety of the entire system.

[0003] In related technologies, IGBT overcurrent protection circuits are designed to provide overcurrent protection only for the IGBT devices monitored by the circuit. In circuit systems with multiple IGBT devices, multiple IGBT overcurrent protection circuits are configured. However, if an IGBT overcurrent protection circuit malfunctions, it can easily lead to damage to the IGBT device under overcurrent conditions, especially in ultrasonic power supplies. Overcurrent in the IGBT device can cause core magnetization and rapid core saturation, resulting in signal distortion in subsequent stages. Utility Model Content

[0004] The purpose of this application is to provide an IGBT overcurrent protection circuit and an ultrasonic power supply, which can provide synchronous overcurrent protection for multiple IGBT devices to avoid damage to the IGBT devices due to overcurrent.

[0005] This application provides an IGBT overcurrent protection circuit, including:

[0006] At least two current detection circuits are connected to the corresponding IGBT devices to collect the current of the IGBT devices and generate a corresponding detection signal when the current of the IGBT devices exceeds a preset current threshold.

[0007] A control circuit, connected to each of the current detection circuits and each of the IGBT devices, drives each of the IGBT devices to power down and turn off when it receives a detection signal generated by at least one of the current detection circuits.

[0008] In some embodiments, the current detection circuit includes:

[0009] The sampling sub-circuit is connected to the collector and emitter of the IGBT device, samples the collector-emitter voltage of the IGBT device, and generates a corresponding voltage sampling signal;

[0010] A signal comparison sub-circuit is connected to the sampling sub-circuit and receives the voltage sampling signal. It compares the voltage sampling signal with a preset voltage signal and generates a corresponding voltage comparison signal when the voltage value of the voltage sampling signal exceeds the voltage value of the preset voltage signal.

[0011] The signal output sub-circuit connects the signal comparison sub-circuit and the control circuit, receives the voltage comparison signal, isolates and converts the voltage comparison signal to generate the detection signal, and outputs the detection signal to the control circuit.

[0012] In some embodiments, the signal comparison sub-circuit includes a signal comparator and its peripheral circuits, wherein the signal comparator is a TL331IDB chip.

[0013] In some embodiments, the signal output sub-circuit includes a signal isolator and its peripheral circuitry, wherein the signal isolator is a TLP152 chip.

[0014] In some embodiments, the control circuit includes:

[0015] The signal processing sub-circuit is connected to each of the current detection circuits and generates a corresponding power-down control signal when it receives a detection signal generated by at least one of the current detection circuits.

[0016] At least two driving sub-circuits are connected to the signal processing sub-circuit and the corresponding IGBT device, and drive the corresponding IGBT device to power down and turn off when the signal processing sub-circuit generates the power-down control signal.

[0017] In some embodiments, the signal processing sub-circuit compares the voltage values ​​of the detection signal and the preset voltage signal, and generates the power-down control signal when the voltage value of the detection signal exceeds the voltage value of the preset voltage signal.

[0018] In some embodiments, the driving sub-circuit receives an external pulse width modulation signal, isolates and converts the pulse width modulation signal to generate the driving signal, outputs the driving signal to power on the IGBT device, and switches to not generating the driving signal when the signal processing sub-circuit generates the power-off control signal.

[0019] In some embodiments, the signal processing sub-circuit generates a corresponding power-on control signal when the current detection circuit finishes generating the detection signal and a preset waiting time is reached, so that each of the driving sub-circuits receiving the power-on control signal drives the IGBT device to power on.

[0020] In some embodiments, the current detection circuit is provided in four groups, and each of the IGBT devices constitutes a full-bridge drive circuit topology.

[0021] This application also provides an ultrasonic power supply, including the above-described IGBT overcurrent protection circuit.

[0022] The beneficial effects of this application are as follows: By configuring at least two sets of current detection circuits to simultaneously detect the current of at least two sets of IGBT devices, and triggering the control circuit to drive all IGBT devices to power down when an overcurrent is detected in at least one set of IGBT devices, synchronous protection of multiple IGBT devices can be achieved, avoiding multiple overcurrent phenomena in IGBT devices that could cause overcurrent damage to the IGBT devices. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the IGBT overcurrent protection circuit provided in the embodiments of this application.

[0024] Figure 2 This is a schematic diagram of the current detection circuit provided in the embodiment of this application.

[0025] Figure 3 This is a schematic diagram of the control circuit provided in the embodiment of this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0027] It should be noted that the terms "first," "second," "third," "fourth," etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a system, product, or device that includes a series of circuits is not necessarily limited to those explicitly listed, but may include other circuits not explicitly listed or inherent to such systems, products, or devices.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0029] This application provides an IGBT overcurrent protection circuit.

[0030] See Figure 1 In one embodiment, the IGBT overcurrent protection circuit includes a current detection circuit 1 and a control circuit 2, wherein at least two sets of current detection circuits 1 are provided, and the number of current detection circuits 1 is the same as the number of IGBT devices.

[0031] Each current detection circuit 1 is connected to a corresponding IGBT device. The current detection circuit 1 is used to collect the current of the IGBT device and generates a corresponding detection signal when the current of the IGBT device exceeds a preset current threshold. Specifically, the current detection circuit 1 performs current detection on the corresponding IGBT device, compares the detected current information with the preset current information, and if the current value corresponding to the detected current information exceeds the current value corresponding to the preset current information, it is determined that the IGBT device is overcurrent. The current detection circuit 1 generates a corresponding detection signal and outputs it to the control circuit 2.

[0032] Control circuit 2 connects each current detection circuit 1 and each IGBT device. Control circuit 2 is used to power down and turn off each IGBT device when it receives a detection signal generated by at least one current detection circuit 1. Specifically, control circuit 2 connects to each IGBT device. When no detection signal is received from a current detection circuit 1, control circuit 2 powers on each IGBT device. When a detection signal is received from one of the current detection circuits 1, control circuit 2 powers down and turns off all IGBT devices, achieving synchronous protection for multiple IGBT devices and preventing overcurrent damage.

[0033] The IGBT overcurrent protection circuit provided in this application embodiment configures at least two sets of current detection circuits 1 to simultaneously detect the current of at least two sets of IGBT devices. When an overcurrent is detected in at least one set of IGBT devices, the control circuit 2 is triggered to drive all IGBT devices to power down and turn off. This can achieve synchronous protection of multiple IGBT devices and avoid multiple IGBT devices from being damaged by overcurrent.

[0034] See also Figure 1 and Figure 2 In one specific embodiment, the current detection circuit 1 includes a sampling sub-circuit 11, a signal comparison sub-circuit 12, and a signal output sub-circuit 13.

[0035] The sampling sub-circuit 11 is connected to the collector and emitter of the IGBT device. The sampling sub-circuit 11 samples the collector-emitter voltage of the IGBT device and generates a corresponding voltage sampling signal. Specifically, one sampling terminal of the sampling sub-circuit 11 is connected to the emitter of the IGBT device, and the other sampling terminal is connected to the collector of the IGBT device to sample the collector-emitter voltage of the IGBT device (also known as desaturation detection). When the emitter current of the IGBT device increases sharply due to a short circuit, the collector-emitter voltage of the IGBT device enters the linear region from the saturation state. The voltage value of the collector-emitter voltage of the IGBT device increases rapidly with the increase of the emitter current. The sampling sub-circuit 11 generates a voltage sampling signal with a corresponding voltage value based on the collector-emitter voltage value of the IGBT device.

[0036] The signal comparison sub-circuit 12 is connected to the sampling sub-circuit 11. The signal comparison sub-circuit 12 receives a voltage sampling signal and compares the voltage sampling signal with a preset voltage signal. When the voltage value of the voltage sampling signal exceeds the voltage value of the preset voltage signal, a corresponding voltage comparison signal is generated. Specifically, the signal comparison sub-circuit 12 receives the voltage sampling signal generated by the sampling sub-circuit 11 and an external preset voltage signal. The voltage sampling signal and the preset voltage signal are compared. If the voltage value of the preset voltage signal is greater than the voltage value of the voltage sampling signal, the IGBT device has not experienced overcurrent and does not output a voltage comparison signal. If the voltage value of the voltage sampling signal is greater than the voltage value of the preset voltage signal, the IGBT device experiences overcurrent and outputs a voltage comparison signal to the signal output sub-circuit 13.

[0037] The signal output sub-circuit 13 connects the signal comparison sub-circuit 12 and the control circuit 2. The signal output sub-circuit 13 receives a voltage comparison signal, isolates and converts the voltage comparison signal, generates a detection signal, and outputs the detection signal to the control circuit 2. Specifically, the signal output sub-circuit 13 is a signal isolation circuit topology. One side of the signal output sub-circuit 13 receives the voltage comparison signal, and the other side generates a corresponding detection signal based on the received voltage comparison signal and outputs it to the control circuit 2. This isolates the voltage comparison signal and the detection signal, preventing signal interference between them.

[0038] In this embodiment, the signal comparator sub-circuit 12 includes a signal comparator U1 and its peripheral circuits. The signal comparator U1 is a TL331IDB chip.

[0039] In this embodiment, the signal output sub-circuit 13 includes a signal isolator U2 and its peripheral circuits. The signal isolator U2 is a TLP152 chip.

[0040] See also Figure 1 and Figure 3 In one specific embodiment, the control circuit 2 includes a signal processing sub-circuit 21 and a driving sub-circuit 22, wherein at least two sets of driving sub-circuits 22 are provided, and the number of driving sub-circuits 22 is the same as the number of IGBT devices.

[0041] The signal processing sub-circuit 21 is connected to each current detection circuit 1. When the signal processing sub-circuit 21 receives a detection signal generated by at least one current detection circuit 1, it generates a corresponding power-down control signal. Specifically, the signal processing sub-circuit 21 monitors each current detection circuit 1 in real time. When at least one current detection circuit 1 generates a detection signal, the signal processing sub-circuit 21 receives the detection signal and generates a corresponding power-down control signal, which is then output to each drive sub-circuit 22.

[0042] The driving sub-circuit 22 connects the signal processing sub-circuit 21 and the corresponding IGBT device. When the signal processing sub-circuit 21 generates a power-down control signal, the driving sub-circuit 22 drives the corresponding IGBT device to power down and turn off. Specifically, when the driving sub-circuit 22 does not receive a power-down control signal generated by the signal processing sub-circuit 21, it drives each IGBT device to power on and turn on; when it receives a power-down control signal generated by the signal processing sub-circuit 21, it drives the corresponding IGBT device to power down and turn off.

[0043] In this embodiment, the signal processing sub-circuit 21 compares the voltage values ​​of the detection signal and the preset voltage signal. When the voltage value of the detection signal exceeds the voltage value of the preset voltage signal, a power-down control signal is generated. Specifically, one input terminal of the signal processing sub-circuit 21 is used to connect to the detection signal generated by the current detection circuit 1, and the other input terminal of the signal processing sub-circuit 21 is connected to an external preset voltage signal. The signal processing sub-circuit 21 compares the voltage values ​​of its two input terminals. If the voltage value of the input terminal connected to the preset voltage signal is greater than the voltage value of the input terminal connected to the detection signal, the IGBT device has not experienced overcurrent and does not output a power-down control signal. If the voltage value of the input terminal connected to the detection signal is greater than the voltage value of the input terminal connected to the preset voltage signal, the IGBT device experiences overcurrent and outputs a power-down control signal to the drive sub-circuit 22. More specifically, the signal processing sub-circuit 21 includes a signal processor U3 and its peripheral circuits. The signal processor U3 is a TL331IDB chip.

[0044] In this embodiment, the driving sub-circuit 22 receives an external pulse width modulation (PWM) signal, isolates and converts the PWM signal to generate a driving signal, and outputs the driving signal to power on the IGBT device. When the signal processing sub-circuit 21 generates a power-down control signal, it switches to not generating a driving signal. Specifically, the driving sub-circuit 22 is a signal isolation circuit topology. One side of the driving sub-circuit 22 receives the PWM signal and connects to the signal processing sub-circuit 21. The other side of the driving sub-circuit 22 generates a corresponding driving signal based on the received PWM signal and outputs it to the IGBT device, thus isolating the PWM signal and the driving signal and preventing signal interference between them. When the signal processing sub-circuit 21 generates a power-down control signal, the driving sub-circuit 22 switches to not generating a driving signal, causing the corresponding IGBT device to power off. More specifically, the driving sub-circuit 22 includes an isolation driver U4 and its peripheral circuitry. The isolation driver U4 is a Pai8233C-WR chip.

[0045] In this embodiment, when the current detection circuit 1 finishes generating the detection signal and the preset waiting time has elapsed, the signal processing sub-circuit 21 generates a corresponding power-on control signal, causing each drive sub-circuit 22 receiving the power-on control signal to power on the IGBT device. Specifically, when the current detection circuit 1 finishes generating the detection signal, the signal processing sub-circuit 21 maintains the output of the power-off control signal to the drive sub-circuit 22 to keep the IGBT device powered off until the preset waiting time has elapsed. When the preset waiting time has elapsed, the signal processing sub-circuit 21 generates a corresponding power-on control signal and outputs it to the drive sub-circuit 22, causing each drive sub-circuit 22 receiving the power-on control signal to power on the IGBT device. More specifically, one input terminal of the signal processor U3 is used to receive the detection signal generated by the current detection circuit 1, and the other input terminal of the signal processor U3 is used to receive an external preset voltage signal. The input terminal of the signal processor U3 that receives the preset voltage signal is connected to the external preset voltage signal through a delay resistor R1 and grounded through a delay capacitor R2. Through the delay resistor R1 and the delay capacitor R2, the signal processor U3 can generate a power-on control signal and output it to the driver sub-circuit 22 when the current detection circuit 1 finishes generating the detection signal and the preset waiting time has elapsed. By configuring the resistance value of the delay resistor R1 and the capacitance value of the delay capacitor R2, the duration of the preset waiting time can be set.

[0046] The IGBT overcurrent protection circuit provided in this application embodiment has four sets of current detection circuits 1, and each IGBT device constitutes a full-bridge drive circuit topology.

[0047] This application also provides an ultrasonic power supply.

[0048] The ultrasonic power supply includes the IGBT overcurrent protection circuit described above. The specific structure of the IGBT overcurrent protection circuit is as described in the above embodiments. Since the ultrasonic power supply provided in this application adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0049] In summary, the IGBT overcurrent protection circuit and ultrasonic power supply provided in this application embodiment, by configuring at least two sets of current detection circuits to simultaneously detect the current of at least two sets of IGBT devices, and triggering the control circuit to drive all IGBT devices to power down when an overcurrent is detected in at least one set of IGBT devices, can achieve synchronous protection of multiple IGBT devices, avoiding multiple overcurrent phenomena in IGBT devices that could cause overcurrent damage to the IGBT devices.

[0050] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0051] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. An IGBT overcurrent protection circuit, characterized in that, include: At least two current detection circuits are connected to the corresponding IGBT devices to collect the current of the IGBT devices and generate a corresponding detection signal when the current of the IGBT devices exceeds a preset current threshold. A control circuit, connected to each of the current detection circuits and each of the IGBT devices, drives each of the IGBT devices to power down and turn off when it receives a detection signal generated by at least one of the current detection circuits.

2. The IGBT overcurrent protection circuit according to claim 1, characterized in that, The current detection circuit includes: The sampling sub-circuit is connected to the collector and emitter of the IGBT device, samples the collector-emitter voltage of the IGBT device, and generates a corresponding voltage sampling signal; A signal comparison sub-circuit is connected to the sampling sub-circuit and receives the voltage sampling signal. It compares the voltage sampling signal with a preset voltage signal and generates a corresponding voltage comparison signal when the voltage value of the voltage sampling signal exceeds the voltage value of the preset voltage signal. The signal output sub-circuit connects the signal comparison sub-circuit and the control circuit, receives the voltage comparison signal, isolates and converts the voltage comparison signal to generate the detection signal, and outputs the detection signal to the control circuit.

3. The IGBT overcurrent protection circuit according to claim 2, characterized in that, The signal comparison sub-circuit includes a signal comparator and its peripheral circuits, wherein the signal comparator is a TL331IDB chip.

4. The IGBT overcurrent protection circuit according to claim 2, characterized in that, The signal output sub-circuit includes a signal isolator and its peripheral circuits, wherein the signal isolator is a TLP152 chip.

5. The IGBT overcurrent protection circuit according to claim 1, characterized in that, The control circuit includes: The signal processing sub-circuit is connected to each of the current detection circuits and generates a corresponding power-down control signal when it receives a detection signal generated by at least one of the current detection circuits. At least two driving sub-circuits are connected to the signal processing sub-circuit and the corresponding IGBT device, and drive the corresponding IGBT device to power down and turn off when the signal processing sub-circuit generates the power-down control signal.

6. The IGBT overcurrent protection circuit according to claim 5, characterized in that, The signal processing sub-circuit compares the voltage values ​​of the detection signal and the preset voltage signal, and generates the power-down control signal when the voltage value of the detection signal exceeds the voltage value of the preset voltage signal.

7. The IGBT overcurrent protection circuit according to claim 5, characterized in that, The driving sub-circuit receives an external pulse width modulation signal, isolates and converts the pulse width modulation signal to generate a driving signal, outputs the driving signal to power on the IGBT device, and switches to not generating the driving signal when the signal processing sub-circuit generates the power-off control signal.

8. The IGBT overcurrent protection circuit according to claim 5, characterized in that, The signal processing sub-circuit generates a corresponding power-on control signal when the current detection circuit finishes generating the detection signal and a preset waiting time has elapsed, so that each of the driving sub-circuits receiving the power-on control signal drives the IGBT device to power on.

9. The IGBT overcurrent protection circuit according to any one of claims 1 to 8, characterized in that, The current detection circuit is configured with four groups, and each of the IGBT devices constitutes a full-bridge drive circuit topology.

10. An ultrasonic power supply, characterized in that, Includes the IGBT overcurrent protection circuit as described in any one of claims 1 to 9.

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