Multi-IGBT parallel current sharing circuit based on voltage feedback

Abstract

The invention relates to the technical field of semiconductors, in particular to a multi-IGBT parallel current sharing circuit based on voltage feedback, which comprises a current sharing circuit and a plurality of IGBT conduction current detection circuits, wherein the IGBT conduction current detection circuits are in one-to-one correspondence with the IGBTs in the plurality of IGBTs which are connected in parallel; the first end of the IGBT conduction current detection circuit is connected with the negative direct current end of the IGBT, the second end of the IGBT conduction current detection circuit is connected with the first end of the current sharing circuit, and the second end of the current sharing circuit is grounded. By the adoption of the scheme, parallel current sharing of multiple IGBTs can be achieved.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a multi-IGBT parallel current sharing circuit based on voltage feedback. 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 current balancing problem of multiple IGBTs in parallel is not considered, which may easily damage the device due to uneven current or increase the redundancy of the current carrying capacity of a single IGBT. Summary of the invention

[0003] The present disclosure provides a multi-IGBT parallel current sharing circuit based on voltage feedback, the main purpose of which is to achieve parallel current sharing of multiple IGBTs.

[0004] According to one aspect of the present disclosure, a multi-IGBT parallel current sharing circuit based on voltage feedback is provided, comprising: a current sharing circuit and a plurality of IGBT on-current detection circuits; wherein,

[0005] The IGBT on-current detection circuit corresponds one-to-one to the IGBTs in the plurality of IGBTs connected in parallel;

[0006] The first end of the IGBT on-current detection circuit is connected to the negative DC end of the IGBT, the second end of the IGBT on-current detection circuit is connected to the first end of the current balancing circuit, and the second end of the current balancing circuit is grounded.

[0007] Optionally, in one embodiment of the present disclosure, the IGBT on-current detection circuit includes a first resistor; wherein,

[0008] The first end of the first resistor is connected to the negative DC terminal of the IGBT, and the second end of the first resistor is connected to the first end of the current balancing circuit.

[0009] Optionally, in one embodiment of the present disclosure, the IGBT on-current detection circuit further includes a first protection module; wherein,

[0010] The first end of the first protection module is connected to the first end of the first resistor, and the second end of the first protection module is connected to the second end of the first resistor.

[0011] Optionally, in an embodiment of the present disclosure, the first protection module includes a first diode; wherein,

[0012] A cathode of the first diode is connected to a first end of the first resistor, and an anode of the first diode is connected to a second end of the first resistor.

[0013] Optionally, in an embodiment of the present disclosure, the current balancing circuit includes a second resistor; wherein,

[0014] A first end of the second resistor is connected to a second end of the IGBT on-current detection circuit, and a second end of the second resistor is grounded.

[0015] Optionally, in an embodiment of the present disclosure, the current balancing circuit further includes a second protection module; wherein,

[0016] The first end of the second protection module is connected to the first end of the second resistor, and the second end of the second protection module is connected to the second end of the second resistor.

[0017] Optionally, in one embodiment of the present disclosure, the second protection module includes a second diode; wherein,

[0018] A cathode of the second diode is connected to a first end of the second resistor, and an anode of the second diode is connected to a second end of the second resistor.

[0019] Optionally, in an embodiment of the present disclosure, the positive DC terminal of the IGBT is connected to a positive DC power supply, the negative DC terminal of the IGBT is connected to a negative DC power supply, and the gate of the IGBT is used to receive a driving signal.

[0020] In summary, the multi-IGBT parallel current equalizing circuit based on voltage feedback provided in the embodiment of the present disclosure can realize current detection for different IGBTs under IGBT parallel working conditions by adopting a unified current equalizing circuit grounding combined with independent IGBT on-current detection circuits between each IGBT, and can dynamically adjust the on-current between IGBT devices through the current equalizing circuit to form a dynamic balance, thereby ensuring that the current flowing through each IGBT device is the same.

[0021] 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

[0022] 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.

[0023] Figure 1A schematic diagram of a multi-IGBT parallel current sharing circuit based on voltage feedback provided by an embodiment of the present disclosure;

[0024] Figure 2 A schematic structural diagram of a multi-IGBT parallel current sharing circuit based on voltage feedback provided in another embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] 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.

[0026] 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.

[0027] The present disclosure is described in detail below with reference to specific embodiments.

[0028] Figure 1 The schematic diagram of the structure of a multi-IGBT parallel current sharing circuit based on voltage feedback provided by the embodiment of the present disclosure. Figure 1 As shown, the multi-IGBT parallel current sharing circuit based on voltage feedback includes: a current sharing circuit and multiple IGBT on-current detection circuits; wherein,

[0029] The IGBT on-current detection circuit corresponds one-to-one to the IGBTs in the plurality of IGBTs connected in parallel;

[0030] The first end of the IGBT on-current detection circuit is connected to the negative DC end of the IGBT, the second end of the IGBT on-current detection circuit is connected to the first end of the current balancing circuit, and the second end of the current balancing circuit is grounded.

[0031] According to some embodiments, when an IGBT among the multiple IGBTs is an N-type IGBT, the negative DC terminal of the IGBT is the emitter and the positive DC terminal is the collector; when an IGBT among the multiple IGBTs is a P-type IGBT, the negative DC terminal of the IGBT is the collector and the positive DC terminal is the emitter.

[0032] It should be noted that by adopting independent IGBT on-current detection circuits between each IGBT, current detection for different IGBTs under IGBT parallel working conditions can be realized. By adopting a unified current balancing circuit grounding, the on-current between IGBT devices can be dynamically adjusted through the current balancing circuit to form a dynamic balance, thereby ensuring that the current flowing through each IGBT device is the same.

[0033] Optionally, in one embodiment of the present disclosure, Figure 2 The schematic diagram of the structure of a multi-IGBT parallel current sharing circuit based on voltage feedback provided by the embodiment of the present disclosure. Figure 2 As shown, the multi-IGBT parallel current sharing circuit based on voltage feedback 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 N-type IGBTs.

[0034] According to some embodiments, the gate of the IGBT is used to receive a driving signal, and the driving 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 driving signal.

[0035] 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-.

[0036] Optionally, in one embodiment of the present disclosure, Figure 2 As shown, the IGBT on-current detection circuit includes a first resistor R1; wherein,

[0037] A first end of the first resistor R1 is connected to the negative DC terminal of the IGBT, and a second end of the first resistor R1 is connected to a first end of the current balancing circuit.

[0038] In some embodiments, the first resistor in the first IGBT on-current detection circuit in the multi-IGBT parallel current sharing circuit based on voltage feedback is R11; the first resistor in the Nth IGBT on-current detection circuit is R1N. Figure 2 As shown, the first end of R11 is connected to the emitter of IGBT1, and the second end of R11 is connected to the first end of the current balancing circuit; the first end of R1N is connected to the emitter of IGBTN, and the second end of R1N is connected to the first end of the current balancing circuit.

[0039] It should be noted that the first resistor R1 is used as an on-current detection element. When the on-currents of different IGBT devices are different, different voltages will be generated between R11 and R1N. Since the voltages at the positive DC terminals of the IGBTs are equal, different voltage differences will be generated between the positive DC terminals and the negative DC terminals of the multiple IGBTs connected in parallel. Since the on-resistance of the IGBT is very small, it will affect the on-current of the IGBT, so that it can cooperate with the current balancing circuit to realize dynamic, high-speed, real-time current balancing control of the IGBT on-current.

[0040] Optionally, in one embodiment of the present disclosure, the IGBT on-current detection circuit further includes a first protection module; wherein,

[0041] The first end of the first protection module is connected to the first end of the first resistor, and the second end of the first protection module is connected to the second end of the first resistor.

[0042] In some embodiments, the first protection module is used to protect the first resistor R1 , thereby improving the reliability of the multi-IGBT parallel current sharing circuit based on voltage feedback.

[0043] According to some embodiments, Figure 2 As shown, the first protection module includes a first diode D1; wherein,

[0044] A cathode of the first diode D1 is connected to a first end of the first resistor R1 , and an anode of the first diode D1 is connected to a second end of the first resistor R1 .

[0045] In some embodiments, the first diode in the first IGBT on-current detection circuit in the multi-IGBT parallel current sharing circuit based on voltage feedback is D11; the first diode in the Nth IGBT on-current detection circuit is D1N. Figure 2 As shown, the first end of R11 is connected to the negative electrode of D11, and the second end of R11 is connected to the positive electrode of D11; the first end of R1N is connected to the negative electrode of D1N, and the second end of R1N is connected to the positive electrode of D1N.

[0046] It should be noted that the first diode D1 can play the role of withstanding voltage and protecting the first resistor R1, and can improve the reliability of the multi-IGBT parallel current sharing circuit based on voltage feedback.

[0047] Optionally, in one embodiment of the present disclosure, the current balancing circuit includes a second resistor R2; wherein,

[0048] A first end of the second resistor R2 is connected to a second end of the IGBT on-current detection circuit, and a second end of the second resistor R2 is grounded.

[0049] In some embodiments, the first end of the second resistor R2 is connected to the second ends of R11 ˜ R1N and the positive electrodes of D11 ˜ D1N respectively.

[0050] It should be noted that the first resistor R1 and the second resistor R2 can form a negative voltage feedback in combination, and the second resistor R2 can play a role in generating a voltage reference.

[0051] For example, if the on-current of a certain IGBT is large, the negative voltage feedback formed by the first resistor R1 and the second resistor R2 can form a voltage difference between the positive DC terminal and the negative DC terminal of the IGBT, thereby reducing the relative voltage between the positive DC terminal and the negative DC terminal of the IGBT, and further reducing the on-current of the IGBT.

[0052] Optionally, in one embodiment of the present disclosure, the current balancing circuit further includes a second protection module; wherein,

[0053] The first end of the second protection module is connected to the first end of the second resistor R2, and the second end of the second protection module is connected to the second end of the second resistor R2.

[0054] In some embodiments, the second protection module is used to protect the second resistor R2, thereby improving the reliability of the multi-IGBT parallel current sharing circuit based on voltage feedback.

[0055] According to some embodiments, Figure 2 As shown, the second protection module includes a second diode D2; wherein,

[0056] A cathode of the second diode D2 is connected to a first end of the second resistor R2 , and an anode of the second diode D2 is connected to a second end of the second resistor R2 .

[0057] In some embodiments, the first diode D2 can play the role of withstanding voltage and protecting the second resistor R2, and can improve the reliability of the multi-IGBT parallel current sharing circuit based on voltage feedback.

[0058] Optionally, in an embodiment of the present disclosure, parameters used by various components in the selection circuit may be calculated based on actual application scenarios.

[0059] Taking a scenario as an example, a high-power wind power converter includes multiple stages of parallel-connected IGBT devices. The IGBT device is a power semiconductor device of the converter main circuit and is responsible for power conversion. Therefore, the resistance values ​​of R11 to R1N, the resistance value of the second resistor R2, and the diode parameters of D11 to D1N and the diode parameters of the second diode D2 can be selected according to the different voltage levels and current levels of the converter main circuit to ensure that the voltage negative feedback meets the control requirements and avoids excessive or low voltage affecting the normal operation of the converter main circuit.

[0060] Optionally, in one embodiment of the present disclosure, components involved in the multi-IGBT parallel current sharing circuit based on voltage feedback, including but not limited to the first resistor R1, the second resistor R2, the first diode D1, the second diode D2, etc., can all adopt high-precision devices, thereby further improving the parallel current sharing effect of the IGBT.

[0061] 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".

[0062] 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".

[0063] 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.

[0064] 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 current sharing circuit based on voltage feedback, characterized in that: include: A current balancing circuit and multiple IGBT on-current detection circuits; wherein, The IGBT on-current detection circuit corresponds one-to-one to the IGBTs in the plurality of IGBTs connected in parallel; The first end of the IGBT on-current detection circuit is connected to the negative DC end of the IGBT, the second end of the IGBT on-current detection circuit is connected to the first end of the current balancing circuit, and the second end of the current balancing circuit is grounded.

2. The multi-IGBT parallel current sharing circuit based on voltage feedback according to claim 1, characterized in that: The IGBT on-current detection circuit includes a first resistor; wherein, The first end of the first resistor is connected to the negative DC terminal of the IGBT, and the second end of the first resistor is connected to the first end of the current balancing circuit.

3. The multi-IGBT parallel current sharing circuit based on voltage feedback according to claim 2, characterized in that: The IGBT on-current detection circuit also includes a first protection module; wherein, The first end of the first protection module is connected to the first end of the first resistor, and the second end of the first protection module is connected to the second end of the first resistor.

4. The multi-IGBT parallel current sharing circuit based on voltage feedback according to claim 3, characterized in that: The first protection module includes a first diode; wherein, A cathode of the first diode is connected to a first end of the first resistor, and an anode of the first diode is connected to a second end of the first resistor.

5. The multi-IGBT parallel current sharing circuit based on voltage feedback according to claim 1, characterized in that: The current balancing circuit includes a second resistor; wherein, A first end of the second resistor is connected to a second end of the IGBT on-current detection circuit, and a second end of the second resistor is grounded.

6. The multi-IGBT parallel current sharing circuit based on voltage feedback according to claim 5, characterized in that: The current balancing circuit also includes a second protection module; wherein, The first end of the second protection module is connected to the first end of the second resistor, and the second end of the second protection module is connected to the second end of the second resistor.

7. The multi-IGBT parallel current sharing circuit based on voltage feedback according to claim 6, characterized in that: The second protection module includes a second diode; wherein, A cathode of the second diode is connected to a first end of the second resistor, and an anode of the second diode is connected to a second end of the second resistor.

8. The multi-IGBT parallel current sharing circuit based on voltage feedback according to claim 1, characterized in that: The positive DC terminal of the IGBT is connected to a positive DC power supply, the negative DC terminal of the IGBT is connected to a negative DC power supply, and the gate of the IGBT is used to receive a driving signal.

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