Multi-IGBT parallel overvoltage detection circuit

Abstract

The invention relates to the technical field of semiconductors, in particular to a multi-IGBT parallel overvoltage detection circuit which comprises an overvoltage detection circuit and an overvoltage hardware protection circuit. Wherein the first end of the overvoltage detection circuit is connected with the positive direct current ends of a plurality of IGBTs which are connected in parallel, the second end of the overvoltage detection circuit is connected with the first end of the overvoltage hardware protection circuit, and the third end of the overvoltage detection circuit is connected with the second end of the overvoltage hardware protection circuit. The third end of the overvoltage hardware protection circuit is connected with the IGBT driving circuit; and when the overvoltage detection circuit detects that the voltage corresponding to the positive direct current end is greater than a first voltage threshold value, the overvoltage hardware protection circuit sends an overvoltage protection signal to the IGBT driving circuit, so that the IGBT driving circuit adjusts the on-off states of the plurality of IGBTs according to the overvoltage protection signal. By the adoption of the scheme, overvoltage suppression and feedback protection can be achieved when a plurality of IGBTs connected in parallel are driven.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a multi-IGBT parallel overvoltage detection circuit. Background Art

[0002] Insulate-Gate Bipolar Transistor (IGBT) combines the advantages of Giant Transistor (GTR) and Power MOSFET, has good characteristics, and is widely used. However, in the prior art, when driving multiple IGBTs connected in parallel, the overvoltage suppression and feedback protection of multiple IGBTs in parallel are not considered, resulting in frequent burnout of IGBT devices due to overvoltage. Summary of the invention

[0003] The present disclosure provides a multi-IGBT parallel overvoltage detection circuit, the main purpose of which is to achieve overvoltage suppression and feedback protection when driving multiple IGBTs connected in parallel.

[0004] According to one aspect of the present disclosure, a multi-IGBT parallel overvoltage detection circuit is provided, comprising: an overvoltage detection circuit and an overvoltage hardware protection circuit; wherein,

[0005] The first end of the overvoltage detection circuit is connected to the positive DC ends of the multiple IGBTs connected in parallel, the second end of the overvoltage detection circuit is connected to the first end of the overvoltage hardware protection circuit, the third end of the overvoltage detection circuit is connected to the second end of the overvoltage hardware protection circuit, and the third end of the overvoltage hardware protection circuit is connected to the IGBT driving circuit;

[0006] When the overvoltage detection circuit detects that the voltage corresponding to the positive DC terminal is greater than a first voltage threshold, the overvoltage hardware protection circuit sends an overvoltage protection signal to the IGBT drive circuit, so that the IGBT drive circuit adjusts the on and off states of the multiple IGBTs according to the overvoltage protection signal.

[0007] Optionally, in an embodiment of the present disclosure, the overvoltage detection circuit includes a first overvoltage detection module and a second overvoltage detection module; wherein,

[0008] The first end of the first overvoltage detection module is connected to the positive DC end of the multiple IGBTs, the connection point between the second end of the first overvoltage detection module and the first end of the second overvoltage detection module is connected to the first end of the overvoltage hardware protection circuit, and the second end of the second overvoltage detection module is connected to the second end of the overvoltage hardware protection circuit.

[0009] Optionally, in one embodiment of the present disclosure, the first overvoltage detection module includes at least one first transient suppression diode; wherein,

[0010] The cathode of the first transient voltage suppression diode is connected to the positive DC terminals of the multiple IGBTs, and the anode of the first transient voltage suppression diode is connected to the first terminal of the second overvoltage detection module and the first terminal of the overvoltage hardware protection circuit.

[0011] Optionally, in an embodiment of the present disclosure, the first overvoltage detection module includes a plurality of first transient suppression diodes connected in series.

[0012] Optionally, in one embodiment of the present disclosure, the second overvoltage detection module includes at least one second transient suppression diode; wherein,

[0013] The cathode of the second transient voltage suppression diode is connected to the second end of the first overvoltage detection module and the first end of the overvoltage hardware protection circuit, and the anode of the second transient voltage suppression diode is connected to the second end of the overvoltage hardware protection circuit.

[0014] Optionally, in an embodiment of the present disclosure, the second overvoltage detection module includes a plurality of second transient suppression diodes connected in series.

[0015] Optionally, in an embodiment of the present disclosure, the overvoltage hardware protection circuit includes a first resistor, a second resistor, a first capacitor, and a first diode; wherein,

[0016] The first end of the first resistor is connected to the second end of the overvoltage detection circuit, the second end of the first resistor is connected to the first end of the first capacitor, the connection point between the second end of the first capacitor, the positive electrode of the first diode and the first end of the second resistor is connected to the third end of the overvoltage detection circuit, and the connection point between the negative electrode of the first diode and the second end of the second resistor is connected to the IGBT drive circuit.

[0017] Optionally, in one embodiment of the present disclosure, it further includes:

[0018] A plurality of secondary overvoltage hardware protection circuits, wherein the first ends of the secondary overvoltage hardware protection circuits are connected to the gates of the IGBTs in a one-to-one correspondence, and the second ends of the secondary overvoltage hardware protection circuits are respectively connected to the third end of the overvoltage detection circuit and the second end of the overvoltage hardware protection circuit;

[0019] When the voltage corresponding to the positive DC terminal is greater than a second voltage threshold, the multiple secondary overvoltage hardware protection circuits control the multiple IGBTs to be in an on state.

[0020] Optionally, in one embodiment of the present disclosure, the secondary overvoltage hardware protection circuit includes a second diode; wherein,

[0021] The anode of the second diode is connected to the third terminal of the overvoltage detection circuit and the second terminal of the overvoltage hardware protection circuit respectively, and the cathode of the second diode is connected to the gate of the IGBT.

[0022] In summary, the multi-IGBT parallel overvoltage detection circuit provided by the embodiment of the present disclosure, when the overvoltage detection circuit detects that the voltage corresponding to the positive DC terminal is greater than the first voltage threshold, the overvoltage hardware protection circuit sends an overvoltage protection signal to the IGBT drive circuit, so that the IGBT drive circuit adjusts the on-off state of multiple IGBTs according to the overvoltage protection signal, thereby achieving the purpose of reducing overvoltage, and realizing overvoltage suppression and feedback protection when driving multiple IGBTs connected in parallel.

[0023] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0025] Figure 1 A schematic diagram of a multi-IGBT parallel overvoltage detection circuit provided by an embodiment of the present disclosure;

[0026] Figure 2 A schematic structural diagram of a multi-IGBT parallel overvoltage detection circuit provided by another embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] Some embodiments of the present disclosure will be described in detail here, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. Various changes, modifications and equivalents of the structures described herein will become apparent after understanding the present disclosure. For example, the connection relationships of the structures described herein are merely examples and are not limited to those connection relationships set forth herein, but can be changed as becomes apparent after understanding the present disclosure, except for connections that must be made with specific connection relationships. In addition, for clarity and brevity, descriptions of features known in the art may be omitted.

[0028] The embodiments described in some embodiments of the present disclosure below do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of structures consistent with some aspects of the present disclosure as detailed in the appended claims.

[0029] It should be noted that IGBT power semiconductor devices are fully controlled devices with high voltage sensitivity, and are easily burned or exploded due to overvoltage. Considering the barrel effect of IGBT drive circuits and other issues, the industry usually increases the voltage resistance and current redundancy of IGBT devices, which results in poor economic efficiency after parallel connection. High-precision drive protection circuits, methods, and digital controllers are needed to solve the above problems.

[0030] The present disclosure is described in detail below with reference to specific embodiments.

[0031] Figure 1 This is a schematic diagram of a multi-IGBT parallel overvoltage detection circuit provided by an embodiment of the present disclosure. Figure 1 As shown, the multi-IGBT parallel overvoltage detection circuit includes: an overvoltage detection circuit and an overvoltage hardware protection circuit; wherein,

[0032] A first end of the overvoltage detection circuit is connected to the positive DC ends of multiple IGBTs connected in parallel, a second end of the overvoltage detection circuit is connected to a first end of the overvoltage hardware protection circuit, a third end of the overvoltage detection circuit is connected to a second end of the overvoltage hardware protection circuit, and a third end of the overvoltage hardware protection circuit is connected to the IGBT drive circuit.

[0033] According to some embodiments, when the overvoltage detection circuit detects that the voltage corresponding to the positive DC terminal is greater than the first voltage threshold, the overvoltage hardware protection circuit sends an overvoltage protection signal to the IGBT drive circuit, so that the IGBT drive circuit adjusts the on-off state of multiple IGBTs according to the overvoltage protection signal, thereby achieving the purpose of reducing overvoltage, and realizing overvoltage suppression and feedback protection when driving multiple IGBTs connected in parallel.

[0034] In some embodiments, the first voltage threshold does not specifically refer to a fixed threshold. The first voltage threshold can be determined according to an actual application scenario, for example.

[0035] In some embodiments, when the IGBT driving circuit adjusts the on / off state of multiple IGBTs according to the overvoltage protection signal, the overvoltage problem of the positive DC terminal of the IGBT can be suppressed by, for example, reducing the switching frequency of the output driving signal. The IGBT overvoltage can also be reduced by reducing the operating current to protect the device from damage. The specific method used can be determined according to the actual application scenario.

[0036] It should be noted that when the IGBT among the multiple IGBTs is an N-type IGBT, the positive DC terminal of the IGBT is the collector and the negative DC terminal is the emitter; when the IGBT among the multiple IGBTs is a P-type IGBT, the positive DC terminal of the IGBT is the emitter and the negative DC terminal is the collector.

[0037] Optionally, in one embodiment of the present disclosure, Figure 2 This is a schematic diagram of a multi-IGBT parallel drive signal synchronization circuit provided by an embodiment of the present disclosure. Figure 2 As shown, the multi-IGBT parallel drive signal synchronization circuit includes N N-type IGBTs from IGBT1 to IGBTN, where N is a positive integer greater than 1. The collectors of the N N-type IGBTs are all connected to the positive DC power supply DC+, and the emitters of the N N-type IGBTs are all connected to the negative DC power supply DC-, thereby realizing parallel connection of the N IGBTs.

[0038] According to some embodiments, the gate of the IGBT is used to receive a drive signal input by the IGBT drive circuit. The drive signals received by different IGBTs may be the same or different, which may be determined according to the actual application scenario. The IGBT may be turned on and off according to the received drive signal.

[0039] In some embodiments, if the multiple IGBTs connected in parallel are P-type IGBTs, the emitters of the P-type IGBTs are all connected to the positive DC power supply DC+, and the collectors of the P-type IGBTs are all connected to the negative DC power supply DC-.

[0040] Optionally, in one embodiment of the present disclosure, the overvoltage detection circuit includes a first overvoltage detection module and a second overvoltage detection module; wherein,

[0041] The first end of the first overvoltage detection module is connected to the positive DC end of multiple IGBTs, the second end of the first overvoltage detection module and the connection point between the first end of the second overvoltage detection module are connected to the first end of the overvoltage hardware protection circuit, and the second end of the second overvoltage detection module is connected to the second end of the overvoltage hardware protection circuit.

[0042] According to some embodiments, the first overvoltage detection module includes at least one first transient suppression diode DZ1; wherein,

[0043] The cathode of the first transient suppression diode DZ1 is connected to the positive DC terminals of the multiple IGBTs, and the anode of the first transient suppression diode DZ1 is connected to the first terminal of the second overvoltage detection module and the first terminal of the overvoltage hardware protection circuit.

[0044] In some embodiments, the first overvoltage detection module includes a plurality of first transient suppression diodes DZ1 connected in series. Figure 2 As shown in DZ11 to DZ1P, P is a positive integer greater than 1.

[0045] According to some embodiments, the second overvoltage detection module includes at least one second transient suppression diode DZ2; wherein,

[0046] The cathode of the second transient suppression diode DZ2 is connected to the second end of the first overvoltage detection module and the first end of the overvoltage hardware protection circuit, and the anode of the second transient suppression diode DZ2 is connected to the second end of the overvoltage hardware protection circuit.

[0047] In some embodiments, the second overvoltage detection module includes a plurality of second transient suppression diodes connected in series, such as Figure 2 As shown in DZ21 to DZ2Q in FIG. 1 , Q is a positive integer greater than 1.

[0048] It should be noted that the number and withstand voltage of the first transient suppression diode DZ1 in the first overvoltage detection module and the number and withstand voltage of the second transient suppression diode DZ2 in the second overvoltage detection module can be determined according to the actual application scenario, thereby determining the first voltage threshold.

[0049] Taking a scenario as an example, a high-power wind power converter includes multiple stages of IGBT devices connected in parallel. The IGBT device is a power semiconductor device of the converter main circuit and is responsible for power conversion. Therefore, the number and withstand voltage of the first transient suppression diode DZ1 and the second transient suppression diode DZ2 can be configured according to the voltage level of the high-power wind power converter to determine the first voltage threshold.

[0050] Optionally, in one embodiment of the present disclosure, the overvoltage hardware protection circuit includes a first resistor R1, a second resistor R2, a first capacitor C1, and a first diode D1; wherein,

[0051] The first end of the first resistor R1 is connected to the second end of the overvoltage detection circuit, the second end of the first resistor R1 is connected to the first end of the first capacitor C1, the connection point between the second end of the first capacitor C1, the anode of the first diode D1 and the first end of the second resistor R2 is connected to the third end of the overvoltage detection circuit, and the connection point between the cathode of the first diode D1 and the second end of the second resistor R2 is connected to the IGBT drive circuit.

[0052] In some embodiments, the first end of the first resistor R1 is connected to the second end of the first overvoltage detection module and the first end of the second overvoltage detection module, and the connection point between the second end of the first capacitor C1, the anode of the first diode D1 and the first end of the second resistor R2 is connected to the second end of the second overvoltage detection module.

[0053] It should be noted that when the voltage corresponding to the positive DC terminal of multiple IGBTs reaches the first voltage threshold, the detected voltage can be fed back to the input terminal of the IGBT drive circuit through the first resistor R1, the second resistor R2, the first capacitor C1, and the first diode D1, and then the on and off of the IGBT can be controlled by the IGBT drive circuit to play a protective role.

[0054] Optionally, in one embodiment of the present disclosure, the multi-IGBT parallel overvoltage detection circuit further includes:

[0055] Multiple secondary overvoltage hardware protection circuits, the first ends of the secondary overvoltage hardware protection circuits are connected to the gates of the IGBTs in a one-to-one correspondence, and the second ends of the secondary overvoltage hardware protection circuits are respectively connected to the third end of the overvoltage detection circuit and the second end of the overvoltage hardware protection circuit.

[0056] According to some embodiments, when the voltage corresponding to the positive DC terminal is greater than the second voltage threshold, the plurality of secondary overvoltage hardware protection circuits control the plurality of IGBTs to be in an on state.

[0057] In some embodiments, the second voltage threshold does not specifically refer to a fixed threshold. The second voltage threshold is greater than the first voltage threshold. The second voltage threshold can be determined according to an actual application scenario, for example.

[0058] According to some embodiments, the secondary overvoltage hardware protection circuit includes a second diode D2; wherein,

[0059] The anode of the second diode D2 is connected to the third end of the overvoltage detection circuit and the second end of the overvoltage hardware protection circuit respectively, and the cathode of the second diode D2 is connected to the gate of the IGBT.

[0060] In some embodiments, the second diode in the first secondary overvoltage hardware protection circuit in the multi-IGBT parallel overvoltage detection circuit is D21; the second diode in the Nth secondary overvoltage hardware protection circuit is D2N. Figure 2 As shown, the positive electrode of D21 is connected to the second end of the first capacitor C1, the positive electrode of the first diode D1, the first end of the second resistor R2 and the third end of the overvoltage detection circuit, and the negative electrode of D21 is connected to the gate of IGBT1; the positive electrode of D2N is connected to the second end of the first capacitor C1, the positive electrode of the first diode D1, the first end of the second resistor R2 and the third end of the overvoltage detection circuit, and the negative electrode of D2N is connected to the gate of IGBTN.

[0061] It should be noted that after the overvoltage detection circuit detects that the voltage corresponding to the positive DC terminal is greater than the first voltage threshold and controls the on and off states of multiple IGBTs through the IGBT drive circuit, if the voltage corresponding to the positive DC terminal is still rising and rises to be greater than the second voltage threshold, multiple secondary overvoltage hardware protection circuits can be set up to interlock with the IGBT drive circuit, drive the IGBT drive circuit to forcibly block the IGBT drive pulse, directly apply the trigger point to the control gate of the IGBT, and then turn on the IGBT, thereby reducing the overvoltage, thereby ensuring equipment safety and improving the reliability of the multi-IGBT parallel overvoltage detection circuit.

[0062] Optionally, in one embodiment of the present disclosure, the components involved in the multi-IGBT parallel overvoltage detection circuit, including but not limited to the first resistor R1, the second resistor R2, the first capacitor C1, the first diode D1, the second diode D2, the first transient suppression diode DZ1, the second transient suppression diode DZ2, etc., can all adopt high-precision devices, thereby further improving the accuracy of multi-IGBT parallel overvoltage detection.

[0063] In addition, the word "exemplary" is used herein to indicate serving as an example, instance, or diagram. Any aspect or design described as "exemplary" in this article is not necessarily understood to be advantageous compared to other aspects or designs. On the contrary, the use of the word exemplary is intended to present concepts in a specific way. As used herein, the term "or" is intended to represent an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or clear from the context, "X applies A or B" is intended to represent any one of the natural inclusive arrangements. That is, if X applies A; X applies B; or X applies both A and B, "X applies A or B" is satisfied under any of the aforementioned examples. In addition, unless otherwise specified or clearly pointed to a singular form from the context, the articles "one" and "an" as used in this application and the appended claims are generally understood to mean "one or more".

[0064] Likewise, although the present disclosure has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art after reading and understanding the specification and drawings. The present disclosure includes all such modifications and variations and is limited only by the scope of the claims. In particular, with respect to the various functions performed by the components (e.g., elements, resources, etc.) described above, unless otherwise noted, the terms used to describe such components are intended to correspond to any component (functionally equivalent) that performs the specific functions of the described components, even if the structure is not equivalent to the disclosed structure. In addition, although the specific features of the present disclosure may have been disclosed with respect to only one of several implementations, such features may be combined with one or more other features of other implementations as may be desired and conducive to any given or specific application. In addition, with respect to "including", "having", "having", "having", or variations thereof used in the specific embodiments or claims, such terms are intended to be inclusive in a manner similar to the term "comprising".

[0065] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0066] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A multi-IGBT parallel overvoltage detection circuit, characterized in that: include: Overvoltage detection circuit and overvoltage hardware protection circuit; wherein, The first end of the overvoltage detection circuit is connected to the positive DC ends of the multiple IGBTs connected in parallel, the second end of the overvoltage detection circuit is connected to the first end of the overvoltage hardware protection circuit, the third end of the overvoltage detection circuit is connected to the second end of the overvoltage hardware protection circuit, and the third end of the overvoltage hardware protection circuit is connected to the IGBT driving circuit; When the overvoltage detection circuit detects that the voltage corresponding to the positive DC terminal is greater than a first voltage threshold, the overvoltage hardware protection circuit sends an overvoltage protection signal to the IGBT drive circuit, so that the IGBT drive circuit adjusts the on and off states of the multiple IGBTs according to the overvoltage protection signal.

2. The multi-IGBT parallel overvoltage detection circuit according to claim 1, characterized in that: The overvoltage detection circuit includes a first overvoltage detection module and a second overvoltage detection module; wherein, The first end of the first overvoltage detection module is connected to the positive DC end of the multiple IGBTs, the connection point between the second end of the first overvoltage detection module and the first end of the second overvoltage detection module is connected to the first end of the overvoltage hardware protection circuit, and the second end of the second overvoltage detection module is connected to the second end of the overvoltage hardware protection circuit.

3. The multi-IGBT parallel overvoltage detection circuit according to claim 2, characterized in that: The first overvoltage detection module includes at least one first transient suppression diode; wherein, The cathode of the first transient voltage suppression diode is connected to the positive DC terminals of the multiple IGBTs, and the anode of the first transient voltage suppression diode is connected to the first terminal of the second overvoltage detection module and the first terminal of the overvoltage hardware protection circuit.

4. The multi-IGBT parallel overvoltage detection circuit according to claim 3, characterized in that: The first overvoltage detection module includes a plurality of first transient suppression diodes connected in series.

5. The multi-IGBT parallel overvoltage detection circuit according to claim 2, characterized in that: The second overvoltage detection module includes at least one second transient suppression diode; wherein, The cathode of the second transient voltage suppression diode is connected to the second end of the first overvoltage detection module and the first end of the overvoltage hardware protection circuit, and the anode of the second transient voltage suppression diode is connected to the second end of the overvoltage hardware protection circuit.

6. The multi-IGBT parallel overvoltage detection circuit according to claim 5, characterized in that: The second overvoltage detection module includes a plurality of second transient suppression diodes connected in series.

7. The multi-IGBT parallel overvoltage detection circuit according to claim 1, characterized in that: The overvoltage hardware protection circuit includes a first resistor, a second resistor, a first capacitor, and a first diode; wherein, The first end of the first resistor is connected to the second end of the overvoltage detection circuit, the second end of the first resistor is connected to the first end of the first capacitor, the connection point between the second end of the first capacitor, the positive electrode of the first diode and the first end of the second resistor is connected to the third end of the overvoltage detection circuit, and the connection point between the negative electrode of the first diode and the second end of the second resistor is connected to the IGBT drive circuit.

8. The multi-IGBT parallel overvoltage detection circuit according to claim 1, characterized in that: Also includes: A plurality of secondary overvoltage hardware protection circuits, wherein the first ends of the secondary overvoltage hardware protection circuits are connected to the gates of the IGBTs in a one-to-one correspondence, and the second ends of the secondary overvoltage hardware protection circuits are respectively connected to the third end of the overvoltage detection circuit and the second end of the overvoltage hardware protection circuit; When the voltage corresponding to the positive DC terminal is greater than a second voltage threshold, the multiple secondary overvoltage hardware protection circuits control the multiple IGBTs to be in an on state.

9. The multi-IGBT parallel overvoltage detection circuit according to claim 8, characterized in that: The secondary overvoltage hardware protection circuit includes a second diode; wherein, The anode of the second diode is connected to the third terminal of the overvoltage detection circuit and the second terminal of the overvoltage hardware protection circuit respectively, and the cathode of the second diode is connected to the gate of the IGBT.

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