Multi-silicon carbide device parallel current sharing circuit based on voltage feedback
By using a voltage feedback mechanism and a conduction current detection circuit in the parallel circuit of multi-silicon carbide devices, the current between devices is dynamically adjusted, and the problem of uneven current when connecting multiple silicon carbide devices in parallel is solved, and current equalization and device safety are achieved.
Patent Information
- Application Number
- CN202411955092.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-04-01
AI Technical Summary
When the prior art connects multiple silicon carbide devices in parallel, it fails to effectively solve the problem of current unevenness, which can easily damage the device or increase redundancy.
The parallel current sharing circuit of polysilicon carbide devices based on voltage feedback is adopted. Through the combination of the current sharing circuit and the conduction current detection circuit of the silicon carbide device, the current detection of different silicon carbide devices is realized, and dynamic balance is formed by dynamic adjustment of the conduction current.
Current equalization is achieved in parallel operation of polysilicon carbide devices, ensuring that the current flows through each device is the same, reducing the risk of device damage and avoiding redundancy problems.
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Figure CN119742998A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a parallel current-sharing circuit of multiple silicon carbide devices based on voltage feedback. Background Art
[0002] Silicon Carbide (SiC) is a material with excellent electrical properties such as wide bandgap, high breakdown electric field, high saturation drift velocity and high thermal conductivity. Compared with other materials, it is more suitable for working under special conditions of high temperature, high power and high frequency. Therefore, the material has attracted widespread attention since its birth. The development of the power electronics industry has always been closely related to the development of semiconductor devices. Under the circumstances that the industry has put forward higher requirements for high frequency and high power, the application of high-power high-frequency induction heating technology to SiC metal-oxide semiconductor field-effect transistor (Metal-Oxide-SemiconductorField-EffectTransistor, MOSFET) has also entered the stage of active exploration. However, in the prior art, when driving multiple silicon carbide devices connected in parallel, the problem of parallel current sharing of multiple silicon carbide devices is not considered, which is easy to damage the device due to uneven current or increase the redundancy of the current-carrying capacity of a single silicon carbide device. Summary of the invention
[0003] The present disclosure provides a parallel current sharing circuit for multiple silicon carbide devices based on voltage feedback, the main purpose of which is to achieve parallel current sharing of multiple silicon carbide devices.
[0004] It ensures that the on / off conversion is completed safely and quickly with minimal switching loss.
[0005] According to one aspect of the present disclosure, a parallel current sharing circuit for multiple silicon carbide devices based on voltage feedback is provided, comprising: a current sharing circuit and a plurality of silicon carbide device conduction current detection circuits; wherein,
[0006] The silicon carbide device on-current detection circuit corresponds one-to-one to the silicon carbide devices in the plurality of silicon carbide devices connected in parallel;
[0007] The first end of the silicon carbide device on-current detection circuit is connected to the negative DC end of the silicon carbide device, the second end of the silicon carbide device 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.
[0008] Optionally, in one embodiment of the present disclosure, the silicon carbide device on-current detection circuit includes a first resistor; wherein,
[0009] The first end of the first resistor is connected to the negative DC end of the silicon carbide device, and the second end of the first resistor is connected to the first end of the current balancing circuit.
[0010] Optionally, in one embodiment of the present disclosure, the silicon carbide device on-current detection circuit further includes a first protection module; wherein,
[0011] 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.
[0012] Optionally, in an embodiment of the present disclosure, the first protection module includes a first diode; wherein,
[0013] 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.
[0014] Optionally, in an embodiment of the present disclosure, the current balancing circuit includes a second resistor; wherein,
[0015] A first end of the second resistor is connected to a second end of the silicon carbide device on-current detection circuit, and a second end of the second resistor is grounded.
[0016] Optionally, in an embodiment of the present disclosure, the current balancing circuit further includes a second protection module; wherein,
[0017] 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.
[0018] Optionally, in one embodiment of the present disclosure, the second protection module includes a second diode; wherein,
[0019] 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.
[0020] Optionally, in one embodiment of the present disclosure, the positive DC terminal of the silicon carbide device is connected to a positive DC power supply, the negative DC terminal of the silicon carbide device is connected to a negative DC power supply, and the gate of the silicon carbide device is used to receive a driving signal.
[0021] In summary, the multi-silicon carbide device parallel current equalizing circuit based on voltage feedback provided in the embodiment of the present disclosure can realize current detection for different silicon carbide devices under the condition of parallel operation of silicon carbide devices by adopting a unified current equalizing circuit grounding combined with independent silicon carbide device on-current detection circuits between each silicon carbide device, and can dynamically adjust the on-current between silicon carbide devices through the current equalizing circuit to form a dynamic balance, thereby ensuring that the current flowing through each silicon carbide device is the same.
[0022] 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
[0023] 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.
[0024] Figure 1 A schematic diagram of a parallel current-sharing circuit for multiple silicon carbide devices based on voltage feedback provided by an embodiment of the present disclosure;
[0025] Figure 2 A schematic diagram of the structure of a parallel current sharing circuit of multiple silicon carbide devices based on voltage feedback provided in another embodiment of the present disclosure. DETAILED DESCRIPTION
[0026] 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.
[0027] 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.
[0028] The present disclosure is described in detail below with reference to specific embodiments.
[0029] Figure 1 This is a schematic diagram of a parallel current sharing circuit for multiple silicon carbide devices based on voltage feedback provided by an embodiment of the present disclosure. Figure 1As shown, the parallel current sharing circuit of multiple silicon carbide devices based on voltage feedback includes: a current sharing circuit and a plurality of silicon carbide device conduction current detection circuits; wherein,
[0030] The silicon carbide device on-current detection circuit corresponds one-to-one to the silicon carbide devices in the plurality of silicon carbide devices connected in parallel;
[0031] The first end of the silicon carbide device on-current detection circuit is connected to the negative DC end of the silicon carbide device, the second end of the silicon carbide device 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.
[0032] According to some embodiments, the silicon carbide device refers to a SiC MOSFET. When the silicon carbide device among the multiple silicon carbide devices is an N-type silicon carbide device, the negative DC terminal of the silicon carbide device is an emitter, and the positive DC terminal is a collector; when the silicon carbide device among the multiple silicon carbide devices is a P-type silicon carbide device, the negative DC terminal of the silicon carbide device is a collector, and the positive DC terminal is an emitter.
[0033] It should be noted that by adopting independent silicon carbide device on-current detection circuits between each silicon carbide device, current detection for different silicon carbide devices under parallel working conditions of silicon carbide devices can be realized. By adopting a unified current balancing circuit grounding, the on-current between silicon carbide devices can be dynamically adjusted through the current balancing circuit to form a dynamic balance, thereby ensuring that the current flowing through each silicon carbide device is the same.
[0034] Optionally, in one embodiment of the present disclosure, Figure 2 This is a schematic diagram of a parallel current sharing circuit for multiple silicon carbide devices based on voltage feedback provided by an embodiment of the present disclosure. Figure 2 As shown, the multi-silicon carbide device parallel current sharing circuit based on voltage feedback includes N N-type silicon carbide devices, SiC MOSFET1 to SiC MOSFETN, where N is a positive integer greater than 1, and the collectors of the N N-type silicon carbide devices are all connected to a positive DC power supply DC+, and the emitters of the N N-type silicon carbide devices are all connected to a negative DC power supply DC-, thereby realizing parallel connection of the N N-type silicon carbide devices.
[0035] According to some embodiments, the gate of the silicon carbide device is used to receive a driving signal, and the driving signals received by different silicon carbide devices may be the same or different, which may be determined according to the actual application scenario. The silicon carbide device can be turned on and off according to the received driving signal.
[0036] In some embodiments, if the multiple silicon carbide devices connected in parallel are P-type silicon carbide devices, the emitters of the P-type silicon carbide devices are all connected to the positive DC power supply DC+, and the collectors of the P-type silicon carbide devices are all connected to the negative DC power supply DC-.
[0037] Optionally, in one embodiment of the present disclosure, Figure 2 As shown, the silicon carbide device on-current detection circuit includes a first resistor R1; wherein,
[0038] A first end of the first resistor R1 is connected to the negative DC end of the silicon carbide device, and a second end of the first resistor R1 is connected to a first end of the current balancing circuit.
[0039] In some embodiments, the first resistor in the on-current detection circuit of the first silicon carbide device in the multi-silicon carbide device parallel current sharing circuit based on voltage feedback is R11; the first resistor in the on-current detection circuit of the Nth silicon carbide device is R1N. Figure 2 As shown, the first end of R11 is connected to the emitter of SiC MOSFET1, 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 SiC MOSFETN, and the second end of R1N is connected to the first end of the current balancing circuit.
[0040] It should be noted that the first resistor R1 is used as an on-current detection element. When the on-currents of different silicon carbide devices are different, different voltages will be generated between R11 and R1N. Since the voltages at the positive DC terminals of the silicon carbide devices are equal, different voltage differences will be generated between the positive DC terminals and the negative DC terminals of the multiple silicon carbide devices connected in parallel. Since the on-resistance of the silicon carbide device is very small, it will affect the on-current of the silicon carbide device, so that it can cooperate with the current balancing circuit to realize dynamic, high-speed, real-time current balancing control of the on-current of the silicon carbide device.
[0041] Optionally, in one embodiment of the present disclosure, the silicon carbide device on-current detection circuit further includes a first protection module; wherein,
[0042] 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.
[0043] In some embodiments, the first protection module is used to protect the first resistor R1, thereby improving the reliability of the multi-silicon carbide device parallel current sharing circuit based on voltage feedback.
[0044] According to some embodiments, Figure 2 As shown, the first protection module includes a first diode D1; wherein,
[0045] 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 .
[0046] In some embodiments, the first diode in the on-current detection circuit of the first silicon carbide device in the multi-silicon carbide device parallel current sharing circuit based on voltage feedback is D11; the first diode in the on-current detection circuit of the Nth silicon carbide device 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.
[0047] 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 parallel current sharing circuit of multiple silicon carbide devices based on voltage feedback.
[0048] Optionally, in one embodiment of the present disclosure, the current balancing circuit includes a second resistor R2; wherein,
[0049] A first end of the second resistor R2 is connected to a second end of the silicon carbide device on-current detection circuit, and a second end of the second resistor R2 is grounded.
[0050] 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.
[0051] 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.
[0052] For example, if the on-current of a silicon carbide device 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 silicon carbide device, thereby reducing the relative voltage between the positive DC terminal and the negative DC terminal of the silicon carbide device, and further reducing the on-current of the silicon carbide device.
[0053] Optionally, in one embodiment of the present disclosure, the current balancing circuit further includes a second protection module; wherein,
[0054] 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.
[0055] In some embodiments, the second protection module is used to protect the second resistor R2, thereby improving the reliability of the multi-silicon carbide device parallel current sharing circuit based on voltage feedback.
[0056] According to some embodiments, Figure 2 As shown, the second protection module includes a second diode D2; wherein,
[0057] 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 .
[0058] 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 parallel current sharing circuit of multiple silicon carbide devices based on voltage feedback.
[0059] 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.
[0060] Taking a scenario as an example, a high-power wind power converter includes multiple stages of parallel silicon carbide devices, which are power semiconductor devices of the converter main circuit and are responsible for power conversion. Therefore, the resistance values of R11~R1N, the resistance value of the second resistor R2, the diode parameters of D11~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.
[0061] Optionally, in one embodiment of the present disclosure, components involved in the parallel current sharing circuit of multiple silicon carbide devices 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 silicon carbide devices.
[0062] 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".
[0063] 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".
[0064] 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.
[0065] 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 parallel current sharing circuit of multiple silicon carbide devices based on voltage feedback, characterized in that: include: A current balancing circuit and a plurality of silicon carbide device conduction current detection circuits; wherein, The silicon carbide device on-current detection circuit corresponds one-to-one to the silicon carbide devices in the plurality of silicon carbide devices connected in parallel; The first end of the silicon carbide device on-current detection circuit is connected to the negative DC end of the silicon carbide device, the second end of the silicon carbide device 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-silicon carbide device parallel current sharing circuit based on voltage feedback according to claim 1, characterized in that: The silicon carbide device on-current detection circuit comprises a first resistor; wherein, The first end of the first resistor is connected to the negative DC end of the silicon carbide device, and the second end of the first resistor is connected to the first end of the current balancing circuit.
3. The parallel current sharing circuit of multiple silicon carbide devices based on voltage feedback according to claim 2, characterized in that: The silicon carbide device 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-silicon carbide device 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 parallel current sharing circuit of multiple silicon carbide devices 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 silicon carbide device on-current detection circuit, and a second end of the second resistor is grounded.
6. The parallel current sharing circuit of multiple silicon carbide devices 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 parallel current sharing circuit of multiple silicon carbide devices 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 parallel current sharing circuit of multiple silicon carbide devices based on voltage feedback according to claim 1, characterized in that: The positive DC terminal of the silicon carbide device is connected to a positive DC power supply, the negative DC terminal of the silicon carbide device is connected to a negative DC power supply, and the gate of the silicon carbide device is used to receive a driving signal.