Current sharing circuit and energy storage system

Abstract

The embodiment of the application relates to the technical field of energy storage, and provides a current sharing circuit and an energy storage system, the circuit comprising: a plurality of parallel bridge arm modules comprising a plurality of silicon carbide devices, an input end of the bridge arm module being used for electrical connection with a digital signal processor; a plurality of current detection modules, a first end of the current detection module being electrically connected with an output end of the bridge arm module; a plurality of current sharing modules, a first end of the current sharing module being electrically connected with a second end of the current detection module, a second end of the current sharing module being used for power supply for a to-be-used electrical equipment, the current detection module, the current sharing module and the bridge arm module corresponding in number.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a current sharing circuit and energy storage system. Background Technology

[0002] Existing PCS (Power Conversion System) systems typically require multiple silicon carbide MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) connected in parallel to meet the power and current requirements of high-current applications. However, in parallel applications of silicon carbide MOSFETs, differences in device parameters and asymmetry in circuit layout become two major bottlenecks restricting balanced current distribution, which in turn affect the stability and efficiency of the overall system performance.

[0003] Traditional current sharing control methods, such as adjusting circuit parameters to make each branch as uniform as possible or relying on precise circuit layout to achieve current sharing, often fail to achieve ideal current balance, especially in complex and high-power PCS applications. Furthermore, overcurrent protection typically employs passive methods, such as fuses or relays. While these methods can protect the circuit to some extent, they have limitations in response speed and accuracy, especially in rapidly changing high-current environments. Utility Model Content

[0004] This application provides a current sharing circuit and energy storage system, which at least solves the problem that the current sharing control method in the related art has limitations in response speed and accuracy in rapidly changing high current environments.

[0005] According to some embodiments of this application, one aspect of this application provides a current sharing circuit, including: multiple parallel bridge arm modules, each including multiple silicon carbide devices, the input terminal of the bridge arm module being electrically connected to a digital signal processor; multiple current detection modules, the first terminal of each current detection module being electrically connected to the output terminal of the bridge arm module; and multiple current sharing modules, the first terminal of each current sharing module being electrically connected to the second terminal of each current detection module, the second terminal of each current sharing module being used to supply power to the device in use, wherein the current detection module, the current sharing module, and the bridge arm module correspond one-to-one in number.

[0006] In some embodiments, the current sharing module is a differential mode inductor.

[0007] In some embodiments, the current detection module is a current transformer.

[0008] In some embodiments, the bridge arm module includes four silicon carbide devices, namely a first silicon carbide device, a second silicon carbide device, a third silicon carbide device, and a fourth silicon carbide device. The drain of the first silicon carbide device is electrically connected to the drain of the second silicon carbide device. The source of the first silicon carbide device is electrically connected to the source of the second silicon carbide device, the drain of the third silicon carbide device, the drain of the fourth silicon carbide device, and the first terminal of the current sharing module. The source of the third silicon carbide device is electrically connected to the source of the fourth silicon carbide device. The gates of the first silicon carbide device, the second silicon carbide device, the third silicon carbide device, and the fourth silicon carbide device are respectively used for electrical connection with the digital signal processor.

[0009] In some embodiments, the current sharing circuit further includes: a first voltage regulator module and a second voltage regulator module, wherein a first terminal of the first voltage regulator module is electrically connected to the Meter clamp terminal of the driver chip, a second terminal of the first voltage regulator module is electrically connected to the gate of the silicon carbide device, a first terminal of the second voltage regulator module is electrically connected to the ground terminal of the driver chip, and a second terminal of the second voltage regulator module is electrically connected to the source of the silicon carbide device, wherein the driver chip is electrically connected between the digital signal processor and the input terminal of the bridge arm module.

[0010] In some embodiments, both the first voltage regulator module and the second voltage regulator module are resistor modules.

[0011] In some embodiments, the current sharing circuit further includes a filtering module for electrically connecting between the Meter clamp terminal of the driver chip and the ground terminal of the driver chip, wherein the driver chip is electrically connected between the digital signal processor and the input terminal of the bridge arm module.

[0012] In some embodiments, the filtering module is a capacitor module.

[0013] In some embodiments, the current sharing circuit further includes: a gate floating shutdown module for electrically connecting between the Meter clamp terminal of the driver chip and the ground terminal of the driver chip, wherein the driver chip is electrically connected between the digital signal processor and the output terminal of the input terminal of the bridge arm module.

[0014] In some embodiments, the current sharing circuit further includes: a differentially configured gate module for electrically connecting between the driver chip and the input terminal of the bridge arm module, wherein the driver chip is electrically connected between the digital signal processor and the input terminal of the bridge arm module.

[0015] In some embodiments, the differential configuration gate module includes: a first resistor module, a second resistor module, and a diode, wherein the cathode of the diode is electrically connected to a first terminal of the second resistor module and the output terminal of the driver chip, the anode of the diode is electrically connected to a first terminal of the first resistor module, and the second terminal of the first resistor module is electrically connected to a second terminal of the second resistor module and the gate of the silicon carbide device.

[0016] In some embodiments, the silicon carbide device is an NMOS (N-type metal-oxide-semiconductor field-effect transistor).

[0017] In some embodiments, the current sharing circuit further includes multiple heat sinks, and the heat sinks and the current sharing module are integrated into the same heat dissipation platform.

[0018] In some embodiments, the radiator is a copper tube radiator or a liquid-cooled radiator.

[0019] According to some embodiments of this application, another aspect of this application provides an energy storage system including any of the current sharing circuits described above.

[0020] The technical solution provided in this application has at least the following advantages: The current detection module can detect the output current of each bridge arm module in real time and quickly feed the signal back to the digital signal processor. This direct and fast feedback mechanism avoids the delay problem in traditional methods, enabling the control system to react instantly to current changes. Each bridge arm module corresponds to a current sharing module and a current detection module. This one-to-one correspondence design makes current sharing control more precise and can independently adjust the current of each bridge arm. Even in rapidly changing high-current environments, it can effectively suppress current imbalance. Combining fast detection and independent control, the digital signal processor can execute more complex control algorithms, such as PID (proportional-integral-derivative) control, fuzzy control, or adaptive control. These algorithms can better adapt to rapid current changes and improve the accuracy and stability of current sharing control. The connection between the current detection module and the digital signal processor enables the system to take protective measures immediately when overcurrent is detected, preventing silicon carbide devices from being damaged due to overload. Compared with existing solutions, this improves response speed and accuracy, solving the problem that traditional current sharing control methods have limitations in response speed and accuracy in rapidly changing high-current environments. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a current sharing circuit provided in one embodiment of this application;

[0023] Figure 2 A schematic diagram of a current sharing circuit including two parallel bridge arm modules is provided in one embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the structure of a silicon carbide device driving circuit provided in an embodiment of this application.

[0025] The above figures include the following reference numerals:

[0026] 100. Bridge arm module; 110. Silicon carbide device; 200. Digital signal processor; 300. Current detection module; 400. Current sharing module; 500. Standby power device; 610. First voltage regulator module; 620. Second voltage regulator module; 700. Driver chip; 800. Filter module; 810. Capacitor module; 820. Third resistor module; 830. Fourth resistor module; 840. Fifth resistor module; 900. Differential configuration gate module; 910. First resistor module; 920. Second resistor module; 930. Diode. Detailed Implementation

[0027] As is known from the background art, traditional current sharing control methods have limitations in response speed and accuracy in rapidly changing high current environments. To solve the above-mentioned technical problems, the embodiments of this application provide a current sharing circuit and energy storage system.

[0028] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0031] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0032] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0033] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0034] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0035] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or it can have another component present in between. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located in between.

[0036] The terminology used in the description of the various embodiments described herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "foreword" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0037] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0038] Figure 1 This is a schematic diagram of a current sharing circuit according to an embodiment of this application, such as... Figure 1 As shown, the current sharing circuit includes:

[0039] Multiple parallel bridge arm modules 100, including multiple silicon carbide devices 110, have input terminals for electrical connection to a digital signal processor 200.

[0040] Specifically, the aforementioned digital signal processor is used to provide drive signals for each bridge arm and control the switching state of each bridge arm in real time, and the aforementioned silicon carbide device is preferably a silicon carbide MOSFET.

[0041] Multiple current detection modules 300, the first end of the current detection module 300 being electrically connected to the output end of the bridge arm module 100.

[0042] Multiple current sharing modules 400 are provided, with the first end of each current sharing module 400 electrically connected to the second end of the current detection module 300. The second end of the current sharing module 400 is used to supply power to the standby equipment 500. The current detection module 300, the current sharing module 400, and the bridge arm module 100 correspond one-to-one in number.

[0043] Through the above embodiments, the current sensing module can detect the output current of each bridge arm module in real time and quickly feed the signal back to the digital signal processor. This direct and fast feedback mechanism avoids the delay problem in traditional methods, enabling the control system to react instantly to current changes. Each bridge arm module corresponds to one current sharing module and one current sensing module. This one-to-one correspondence design makes current sharing control more precise, allowing independent adjustment of the current of each bridge arm. Even in rapidly changing high-current environments, it can effectively suppress current imbalance. Combining fast detection and independent control, the digital signal processor can execute more complex control algorithms, such as PID (proportional-integral-derivative) control, fuzzy control, or adaptive control. These algorithms can better adapt to rapid current changes, improving the accuracy and stability of current sharing control. The connection between the current sensing module and the digital signal processor enables the system to take immediate protective measures when overcurrent is detected, preventing damage to silicon carbide devices due to overload. Compared with existing solutions, this improves response speed and accuracy, solving the limitations of traditional current sharing control methods in response speed and accuracy in rapidly changing high-current environments.

[0044] In one alternative, the current sharing module is a differential mode inductor.

[0045] In the above embodiments, when multiple silicon carbide device branches are connected in parallel, uneven current distribution can easily occur due to inconsistent device parameters and parasitic inductance and resistance. A differential-mode inductor connected in series in each branch suppresses current changes, making the current more balanced across branches and improving the parallel current sharing effect. When a branch device has a lower on-resistance, it will preferentially carry more current. The differential-mode inductor forms an additional impedance in steady state, suppressing the current in that branch and gradually redistributing the current, thus preventing long-term overcurrent and overheating in a particular branch. During switching transients or rapid load changes, the current in a branch may suddenly increase; the magnetic field coupling effect of the differential-mode inductor counteracts this surge, limiting rapid current shift and suppressing dynamic current imbalance between branches, preventing instantaneous overcurrent breakdown in a single branch. Furthermore, asymmetrical printed circuit board traces and inconsistent device distribution can lead to different parasitic inductances. The balancing effect of the differential-mode inductor can weaken the current distribution deviation caused by these inconsistencies, improving system tolerance. Differential-mode inductors impede high-frequency components, making the current rise or fall slope smoother, further reducing the peak current when parallel devices are switched, and reducing electromagnetic interference. At the same time, current-sharing inductors ensure that the current sharing of multiple silicon carbide devices is more balanced, avoiding overheating and overcurrent of individual devices, and extending device life.

[0046] In another alternative, the aforementioned current detection module is a current transformer.

[0047] In the above embodiments, the current transformer can proportionally convert the large current on the primary side into a small current or voltage signal on the secondary side, facilitating controller acquisition. It exhibits good linearity and low temperature drift, ensuring accurate detection of the current in parallel branches, thereby improving the accuracy of current sharing control. Furthermore, the current transformer possesses inherent electrical isolation characteristics, with the secondary side physically isolated from the primary side. This separation of the control circuit from the high-voltage, high-current power circuit effectively protects the safety of low-voltage components such as the digital signal processor and driver chip, preventing overvoltage or surge conduction. For rapidly changing currents, the current transformer responds quickly and accurately captures overcurrent signals. Compared to shunt resistors, the current transformer experiences almost no additional power loss when detecting current, introducing no additional heat generation and not affecting the efficiency of the power loop. When using a current transformer as the detection element, the large current in parallel branches can be proportionally converted into a smaller detection current, achieving high-precision acquisition; simultaneously, the current transformer's excellent electrical isolation characteristics isolate the control circuit from the high-voltage power circuit, improving system safety. Because current transformers have the advantages of wide range and fast response, they can accurately capture overcurrent signals under conditions of high current and high current change rate, facilitating timely triggering of protection actions; moreover, they generate almost no additional power consumption during the detection process, reducing the system's energy loss. Through the above design, the reliability and anti-interference capability of current detection are improved, thereby further enhancing the overall stability and safety of the current sharing circuit.

[0048] In some exemplary embodiments, the bridge arm module includes four silicon carbide devices, namely a first silicon carbide device, a second silicon carbide device, a third silicon carbide device, and a fourth silicon carbide device. The drain of the first silicon carbide device is electrically connected to the drain of the second silicon carbide device. The source of the first silicon carbide device is electrically connected to the source of the second silicon carbide device, the drain of the third silicon carbide device, the drain of the fourth silicon carbide device, and the first terminal of the current sharing module. The source of the third silicon carbide device is electrically connected to the source of the fourth silicon carbide device. The gates of the first silicon carbide device, the second silicon carbide device, the third silicon carbide device, and the fourth silicon carbide device are respectively used for electrical connection with the digital signal processor.

[0049] In the above embodiments, the bridge arm module includes four silicon carbide (SiC) devices. Compared to a single SiC device, the four-transistor structure can share current and heat, avoiding overcurrent and overheating in a single transistor. Both the upper and lower bridge arms consist of two parallel SiC devices, resulting in a more symmetrical electrical and thermal distribution. This facilitates the function of the subsequent current sharing module and reduces the impact of parasitic inductance, resistance, and capacitance caused by inconsistencies in parasitic parameters between branches. The gates of the four SiC devices are connected to the control terminals of a digital signal processor (DSP), which can independently or in groups control the conduction or shutdown of each device. This not only enables normal pulse width modulation (PWM) drive but also allows for rapid and precise shutdown of a specific device in case of abnormal current, achieving overcurrent protection. The four-transistor bridge arm structure, combined with the high efficiency of SiC devices, results in lower losses during high-frequency, high-power operation. Simultaneously, parallel sharing and DSP control ensure the safety and stability of the circuit. By employing four silicon carbide devices in a parallel half-bridge topology within the bridge arm module, the current-carrying capacity of a single bridge arm can be effectively improved, reducing the overcurrent risk of individual devices. Furthermore, the symmetry and current-sharing characteristics of the circuit are enhanced. The gates of each device are electrically connected to a digital signal processor, enabling the controller to adjust and protect the switching states of the bridge arms in real time, further improving the circuit's reliability and operating efficiency.

[0050] In other exemplary embodiments, such as Figure 1 and Figure 2As shown, the current sharing circuit further includes: a first voltage regulator module 610 and a second voltage regulator module 620. The first end of the first voltage regulator module 610 is electrically connected to the Meter clamp terminal of the driver chip 700, and the second end of the first voltage regulator module 610 is electrically connected to the gate of the silicon carbide device 110. The first end of the second voltage regulator module 620 is electrically connected to the ground terminal of the driver chip 700, and the second end of the second voltage regulator module 620 is electrically connected to the source of the silicon carbide device 110. The driver chip 700 is electrically connected between the input terminals of the digital signal processor 200 and the bridge arm module 100.

[0051] In the above embodiments, silicon carbide devices have fast switching speeds and significant parasitic capacitance, which can easily lead to interference with the gate voltage. By electrically connecting the first terminal of the first voltage regulator module to the Met clamp terminal of the driver chip, a stable reference is provided, which can clamp the gate at a low potential during the turn-off process and avoid mis-turn-on due to voltage coupling. The first terminal of the second voltage regulator module is used to electrically connect to the ground terminal of the driver chip to ensure a stable potential difference between the gate and the source and prevent malfunction. During the switching process, the gate of the silicon carbide device may experience spikes or oscillations due to parasitic inductance or capacitance mismatch. The voltage regulator module can effectively absorb spike energy, reduce gate overshoot amplitude, reduce oscillation, and avoid the risk of damage to the device gate oxide layer due to overshoot. In addition, in the parallel application of silicon carbide devices, if the gate voltage of a certain device is unstable, it may turn on prematurely or turn off late, causing uneven branch current. By unifying the gate and source voltage characteristics through the voltage regulator module, the switching sequence of multiple parallel silicon carbide devices is made closer, improving the consistency of current distribution. The voltage regulator module acts as a buffer and stabilizes the voltage between the driver chip and the power device. This ensures stable transmission of the drive signal even at high frequencies, reducing the risk of false triggering due to electromagnetic interference. Furthermore, the stable drive voltage reduces the number of times the device repeatedly enters the critical conduction region, lowering switching losses and thermal shock, and effectively extending the lifespan of the silicon carbide device. In summary, by placing a first voltage regulator module and a second voltage regulator module between the driver chip and the silicon carbide device, the gate and source voltages can be effectively stabilized during high-speed switching, avoiding false turn-on or false turn-off caused by the Miller effect. Simultaneously, gate voltage spikes and oscillations are suppressed, improving the switching consistency of parallel devices. This not only enhances the driver chip's anti-interference capability under high-frequency, high-voltage environments but also significantly reduces the risk of damage to the silicon carbide, thereby improving system reliability and lifespan.

[0052] Specifically, the aforementioned current sharing circuit may include multiple parallel bridge arm modules. It should be understood that each bridge arm module may be configured with a corresponding first voltage regulator module and a second voltage regulator module, which are respectively connected to the Miller clamp terminal and the ground terminal of the corresponding driver chip to realize the voltage regulation control of the gate-source voltage of the silicon carbide device in the bridge arm module.

[0053] In some further exemplary embodiments of this application, both the first voltage regulator module and the second voltage regulator module are resistor modules.

[0054] In the above embodiments, the resistor module achieves voltage regulation without requiring complex circuits or dedicated voltage regulator chips. Its simple structure makes it easy to arrange on printed circuit boards, resulting in low cost and suitability for applications with a large number of parallel branches. The resistor, connected in series in the drive channel, divides and buffers the voltage between the gate and source, effectively suppressing voltage spikes generated by switching transients. During high-speed switching of silicon carbide devices, the gate circuit is prone to resonance due to parasitic inductance and capacitance; the resistor module provides appropriate damping, reducing oscillation amplitude and improving the stability of the gate signal. Furthermore, the resistor module makes the gate voltage transition smoother, reducing electrical stress on the device, thereby reducing the risk of gate oxide layer damage to silicon carbide devices during long-term operation and extending device lifespan. By setting the first and second voltage regulator modules as resistor modules, gate voltage regulation and limiting can be achieved in a simple and low-cost manner. The resistor module provides voltage division and damping during high-speed switching, effectively suppressing gate voltage overshoot and oscillation, ensuring the stability of the switching characteristics of parallel silicon carbide devices, extending device lifespan, and improving current sharing.

[0055] In one alternative embodiment, the current sharing circuit further includes a filter module for electrically connecting between the Meter clamp terminal of the driver chip and the ground terminal of the driver chip, wherein the driver chip is electrically connected between the digital signal processor and the input terminal of the bridge arm module.

[0056] In the above embodiments, due to the very fast switching speed of silicon carbide (SiC) devices, the gate of the SiC device is susceptible to interference from noise and parasitic capacitance coupling. By adding a filter module between the Miller clamp terminal and ground, high-frequency interference signals can be effectively filtered out, maintaining the stability of the gate voltage. In the off state, if the gate is momentarily pulled up above the threshold voltage due to coupling interference, false turn-on may occur, leading to short circuits in the upper and lower bridge arms. By adding a filter module, these transient interferences can be quickly filtered out, preventing malfunctions of the SiC device and thus improving system safety. In addition, high-frequency spike currents and voltage oscillations not only affect the gate but also generate electromagnetic interference in the system. The filter module's characteristic of allowing low-frequency signals to pass smoothly in the gate drive circuit while attenuating or filtering high-frequency signals can suppress high-frequency noise conduction, reduce electromagnetic interference radiation, and improve the electromagnetic compatibility of the entire circuit. Due to the differences in gate circuit characteristics between parallel devices, the interference levels of different branches vary, which may cause inconsistent switching timing. Furthermore, being in a highly interfering environment for a long time will accelerate the loss of the gate oxide layer of silicon carbide devices. By setting a filter module between the Miller clamp terminal and the ground terminal of the driver chip, the driving environment of each silicon carbide device can be made more stable, reducing the impact of parasitic parameter differences and improving current sharing performance.

[0057] Specifically, such as Figure 3 As shown, the filter module 800 includes a capacitor module 810. The first end of the capacitor module 810 is electrically connected to the second end of the third resistor module 820 and the first end of the fourth resistor module 830. The second end of the capacitor module 810 is electrically connected to the second end of the fifth resistor module 840 and the second end of the fourth resistor module 830. The first end of the third resistor module 820 is electrically connected to the Meter clamp terminal B1_VCP2 of the driver chip 700. The first end of the fifth resistor module 840 is electrically connected to the ground terminal B1_GND2 of the driver chip 700. The first end of the fourth resistor module 830 is electrically connected to the gate of the silicon carbide device, and the second end of the fourth resistor module 830 is electrically connected to the source of the silicon carbide device.

[0058] In another alternative, the filtering module mentioned above is a capacitor module.

[0059] In the above embodiments, since the capacitor has low impedance at high frequencies and high impedance at low frequencies, when the capacitor module is connected between the Miller clamp terminal and the ground terminal, it can quickly bypass high-frequency interference signals to ground, thus retaining only the low-frequency effective drive signal, forming a low-pass filter. This effectively filters out high-frequency voltage spikes caused by switching transients. High-speed switching of silicon carbide devices can easily lead to gate voltage overshoot or oscillation. The capacitor module provides a buffer for the gate signal, absorbing high-frequency spikes, reducing voltage oscillations, and maintaining a stable gate potential. Furthermore, in the off state, the high voltage change rate can couple interference to the gate through the Miller capacitor. The capacitor module can quickly discharge these interference currents to ground, preventing the gate voltage from rising above the threshold and preventing false turn-on. The capacitor module absorbs and bypasses these high-frequency components, reducing the amplitude of electromagnetic interference and improving the electromagnetic compatibility of the circuit. Different branch devices may be subject to different interferences, leading to differences in switching timing. The capacitor filter module makes the gate voltages of each branch more uniform, ensuring the switching synchronization of parallel silicon carbide devices and contributing to current sharing. During long-term operation, if the gate is frequently subjected to spikes and oscillations, it will accelerate the damage to the gate oxide layer. By setting the filter module as a capacitor module, the electrical stress on the gate is reduced, the anti-interference ability and operational reliability of the circuit are improved, the device life is extended, and the overall system reliability is improved.

[0060] In some exemplary embodiments, the current sharing circuit further includes a gate floating shutdown module for electrically connecting between the Meter clamp terminal of the driver chip and the ground terminal of the driver chip, wherein the driver chip is electrically connected between the digital signal processor and the output terminal of the input terminal of the bridge arm module.

[0061] In the above embodiments, when the driver chip does not output a signal, the power supply is abnormal, or the device is temporarily disconnected, the gate of the silicon carbide device may be in a floating state, that is, neither pulled high nor effectively pulled low. At this time, if there is electromagnetic interference or Miller effect coupling, the gate voltage may be raised above the threshold, causing the silicon carbide device to falsely turn on. By setting a gate floating turn-off module, a stable pull-down path is provided when the gate is floating, clamping the gate potential at a safe level and preventing malfunction. In unexpected situations such as loss of drive signal, digital signal processor reset, or power failure, the gate is easily uncontrollable due to being floating. With the gate floating turn-off module, even if the drive signal is not present, the silicon carbide device can be reliably turned off, avoiding direct short circuits between the upper and lower bridge arms. In addition, since the voltage change rate of the silicon carbide device is large during high-speed switching, the drain voltage change will be coupled to the gate through Miller capacitance. If the gate is floating, this interference will directly cause false turn-on. With the floating turn-off module, this coupled charge can be quickly released to ground, ensuring that the gate remains at a low potential. In parallel applications of silicon carbide devices, if a silicon carbide device in one branch is mistakenly turned on due to floating, it will bear a large current alone, leading to uneven current or even burnout. Through floating turn-off design, all parallel devices are in a reliable turn-off state when there is no drive, avoiding abnormal branch current distribution. Furthermore, being in an unstable floating state for a long time will increase the electrical stress on the gate oxide layer. Reliable floating turn-off can reduce this stress accumulation and extend the working life of silicon carbide devices.

[0062] In some other exemplary embodiments, the current sharing circuit further includes: a differentially configured gate module for electrically connecting between the driver chip and the input terminal of the bridge arm module, wherein the driver chip is electrically connected between the digital signal processor and the input terminal of the bridge arm module.

[0063] In the above embodiments, silicon carbide devices have extremely fast switching speeds. If all devices use the same gate resistor, overshoot, oscillation, or excessive electromagnetic interference may occur. Differential configuration gate modules optimize turn-on and turn-off speeds by setting different resistance values ​​in the turn-on and turn-off paths. Smaller turn-on resistance reduces conduction delay and turn-on losses; larger turn-off resistance delays the turn-off edge, reducing voltage overshoot and oscillation. Differential configuration resistors provide damping at different phases, suppressing overshoot, stabilizing waveforms, and preventing false turn-on or overheating caused by gate oscillation. Furthermore, if all devices switch rapidly, the rate of change of voltage and current is too large, generating strong electromagnetic interference. Differential configuration allows the switching speed to vary within a controllable range, reducing electromagnetic interference and improving electromagnetic compatibility. Moreover, due to process differences, the switching speeds of parallel silicon carbide devices are not entirely the same. Differential configuration gate modules can individually adjust the gate resistance value for the characteristics of different devices, making the turn-on or turn-off of each device more consistent. The optimized switching waveform reduces the electrical stress on the devices, preventing damage due to overshoot or oscillation.

[0064] In one alternative, such as Figure 3 As shown, the differential configuration gate module 900 includes: a first resistor module 910, a second resistor module 920, and a diode 930. The cathode of the diode 930 is electrically connected to the first terminal of the second resistor module 920 and the output terminal B1_G2 of the driver chip 700, respectively. The anode of the diode 930 is electrically connected to the first terminal of the first resistor module 910. The second terminal of the first resistor module 910 is electrically connected to the second terminal of the second resistor module 920 and the gate of the silicon carbide device 110, respectively.

[0065] In the above embodiments, the current path differs during the turn-on and turn-off processes of the silicon carbide device. During turn-on, the drive current passes through the diode to the first resistor module and then to the gate; during turn-off, the drive current passes through the second resistor module and discharges to the gate. Because the first and second resistors can be selected with different resistance values, rapid turn-on is possible, reducing turn-on losses. A larger turn-off resistor slows down the current drop, reducing overshoot and oscillation. During turn-off, if the current drops too quickly, it can cause drain voltage overshoot or loop oscillation. Using a larger turn-off resistor slows down the current drop, suppressing overshoot and preventing the silicon carbide device from experiencing voltage surges exceeding its rated value at the moment of turn-off. High-speed switching of silicon carbide devices easily causes electromagnetic interference. Through differentiated configuration, a faster turn-on speed and a slower turn-off speed result in smoother voltage changes, reducing electromagnetic interference radiation and improving electromagnetic compatibility. Furthermore, differentiated gate configurations make the switching behavior of each device more consistent, reducing current imbalance caused by one path turning on or off first. Furthermore, gate voltage overshoot and oscillation are among the main causes of gate oxide failure in silicon carbide devices. Differential configuration design suppresses these problems, reduces gate stress, and improves the long-term reliability and lifespan of the device. Moreover, the circuit is simple to implement and flexible to adjust. It can achieve separate control of turn-on and turn-off using only a combination of resistors and diodes. Adjusting the resistance value can adapt to different power levels and switching speed requirements, making it highly flexible.

[0066] In another alternative, the silicon carbide device mentioned above is an NMOS.

[0067] In the above embodiments, NMOS is an N-channel metal-oxide-semiconductor field-effect transistor with high electron mobility and low on-resistance. It switches faster than traditional silicon devices and can withstand higher voltage or current change rates. It maintains low loss even under high-frequency pulse-width modulation control, increasing system power density and reducing the size of magnetic components. Furthermore, NMOS has high voltage withstand capability, meeting the system's safe operation requirements in high-voltage applications. Compared to P-type devices, NMOS is simpler to drive, requiring only a positive voltage to the gate to turn it on. NMOS also features good consistency and superior temperature characteristics, resulting in more stable current sharing when multiple devices are connected in parallel, reducing current imbalance caused by parameter deviations and extending the power module's lifespan. In addition, NMOS maintains low on-resistance and stable breakdown voltage even at high temperatures. In the current sharing circuit of this solution, the reliability of the entire system under high power, high temperature, and complex operating conditions can be significantly improved.

[0068] In some exemplary embodiments, the current sharing circuit further includes multiple heat sinks, and the heat sinks and the current sharing module are integrated into the same heat dissipation platform.

[0069] In the above embodiments, both the silicon carbide devices and the current-sharing inductor generate heat during operation. Integrating them onto the same heat dissipation platform increases the heat dissipation area and shortens the overall heat conduction path, thus improving heat dissipation efficiency. If the silicon carbide and inductor are cooled separately, uneven temperature distribution will occur, leading to differences in device performance. Integrating them onto the same heat dissipation platform can achieve uniform heat distribution, reduce temperature differences between devices, and help improve current distribution of parallel silicon carbide devices, enhancing current sharing. Furthermore, integrating the heat sink with the current sharing module reduces the use of independent heat sinks and heat dissipation substrates, resulting in a more compact structure, reduced system size and weight, and shorter electrical connection paths, reducing parasitic inductance and resistance, thereby further suppressing switching overshoot and current unevenness, and improving circuit stability. In addition, the integrated heat dissipation platform facilitates modular power design, allowing the entire current sharing circuit to be assembled or replaced as an independent module, improving system maintenance efficiency.

[0070] In some other exemplary embodiments, the heat sink is a copper tube heat sink or a liquid-cooled heat sink.

[0071] In the above embodiments, due to the high thermal conductivity of copper, the heat generated by the silicon carbide devices and inductors can be quickly transferred to the heat dissipation substrate or external air. The heat is then efficiently removed by the coolant circulating in pipes or cold plates, resulting in higher heat dissipation capacity than air cooling, making it suitable for high-power, high-density applications. Furthermore, silicon carbide devices are temperature-sensitive; high junction temperatures accelerate aging and even breakdown. The core of the current-sharing inductor is prone to saturation at high temperatures, and the winding insulation performance deteriorates. Efficient heat dissipation keeps the device temperature within the rated range, preventing overheating failure and extending lifespan. Moreover, copper pipe cooling and liquid cooling have high heat exchange efficiency, allowing the same heat dissipation task to be completed in a smaller volume. Compared to traditional air cooling, this reduces the number or speed of fans, lowers noise, and improves system stability.

[0072] This application provides an energy storage system, including any of the above-described current sharing circuits.

[0073] Specifically, the aforementioned energy storage system may include an energy storage battery pack, an energy conversion module, and a current sharing circuit electrically connected to the energy conversion module. The energy conversion module is used to convert the DC power output from the energy storage battery pack into AC power, or vice versa, to achieve bidirectional energy flow. The current sharing circuit is applied in the inverter unit or conversion unit of the energy conversion module to perform current balancing control on multiple parallel silicon carbide power devices, thereby ensuring a more uniform current distribution in each parallel branch and preventing overcurrent heating in some power devices.

[0074] In the above embodiments, by employing any of the aforementioned current sharing circuits, the energy storage system can achieve coordinated static and dynamic current sharing through current detection of parallel power branches and differential-mode inductor current sharing combined with gate drive control. This ensures a more balanced current distribution across parallel branches while preventing overcurrent in any single branch, thereby reducing the risk of device overheating failure and improving overall system reliability. Simultaneously, gate regulation and filtering suppress mis-conduction and electromagnetic interference caused by high voltage and current change rates, improving electromagnetic compatibility and switching timing consistency. A unified heat dissipation platform further enhances the uniformity of temperature fields in key components, reducing losses and temperature rise, and increasing power density and lifespan. Therefore, the aforementioned energy storage system maintains high operating efficiency and long-term stability even under high power density, complex power grid, and dynamic load conditions.

[0075] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A current sharing circuit, characterized in that, include: Multiple parallel bridge arm modules (100) include multiple silicon carbide devices (110), and the input terminals of the bridge arm modules (100) are used for electrical connection with a digital signal processor (200); Multiple current detection modules (300), the first end of which is electrically connected to the output end of the bridge arm module (100); Multiple current sharing modules (400) are provided, with the first end of each current sharing module (400) electrically connected to the second end of the current detection module (300). The second end of each current sharing module (400) is used to supply power to the equipment (500) in standby mode. The current detection module (300), the current sharing module (400), and the bridge arm module (100) correspond one-to-one in number. A first voltage regulator module (610) and a second voltage regulator module (620) are provided. The first end of the first voltage regulator module (610) is electrically connected to the Meter clamp terminal of the driver chip (700). The second end of the first voltage regulator module (610) is electrically connected to the gate of the silicon carbide device (110). The first end of the second voltage regulator module (620) is electrically connected to the ground terminal of the driver chip (700). The second end of the second voltage regulator module (620) is electrically connected to the source of the silicon carbide device (110). The driver chip (700) is electrically connected between the digital signal processor (200) and the input terminal of the bridge arm module (100).

2. The current sharing circuit according to claim 1, characterized in that, The current sharing module (400) is a differential mode inductor.

3. The current sharing circuit according to claim 1, characterized in that, The current detection module (300) is a current transformer.

4. The current sharing circuit according to claim 1, characterized in that, The bridge arm module (100) includes four silicon carbide devices (110), namely a first silicon carbide device, a second silicon carbide device, a third silicon carbide device, and a fourth silicon carbide device. The drain of the first silicon carbide device is electrically connected to the drain of the second silicon carbide device. The source of the first silicon carbide device is electrically connected to the source of the second silicon carbide device, the drain of the third silicon carbide device, the drain of the fourth silicon carbide device, and the first terminal of the current sharing module (400). The source of the third silicon carbide device is electrically connected to the source of the fourth silicon carbide device. The gates of the first silicon carbide device, the second silicon carbide device, the third silicon carbide device, and the fourth silicon carbide device are respectively used to be electrically connected to the digital signal processor (200).

5. The current sharing circuit according to claim 1, characterized in that, Both the first voltage regulator module (610) and the second voltage regulator module (620) are resistor modules.

6. The current sharing circuit according to claim 1, characterized in that, The current sharing circuit further includes a filter module (800) for electrically connecting between the Meter clamp terminal of the driver chip (700) and the ground terminal of the driver chip (700), wherein the driver chip (700) is electrically connected between the digital signal processor (200) and the input terminal of the bridge arm module (100).

7. The current sharing circuit according to claim 6, characterized in that, The filtering module (800) is a capacitor module.

8. The current sharing circuit according to claim 1, characterized in that, The current sharing circuit further includes a gate floating shutdown module for electrically connecting between the Meter clamp terminal of the driver chip (700) and the ground terminal of the driver chip (700), wherein the driver chip (700) is electrically connected between the digital signal processor (200) and the output terminal of the input terminal of the bridge arm module (100).

9. The current sharing circuit according to claim 1, characterized in that, The current sharing circuit further includes: a differentially configured gate module (900) for electrically connecting between the driver chip (700) and the input terminal of the bridge arm module (100), wherein the driver chip (700) is electrically connected between the digital signal processor (200) and the input terminal of the bridge arm module (100).

10. The current sharing circuit according to claim 9, characterized in that, The differential configuration gate module (900) includes: a first resistor module (910), a second resistor module (920), and a diode (930). The negative terminal of the diode (930) is electrically connected to the first terminal of the second resistor module (920) and the output terminal of the driver chip (700), respectively. The positive terminal of the diode (930) is electrically connected to the first terminal of the first resistor module (910), and the second terminal of the first resistor module (910) is electrically connected to the second terminal of the second resistor module (920) and the gate of the silicon carbide device (110), respectively.

11. The current sharing circuit according to claim 1, characterized in that, The silicon carbide device (110) is an NMOS.

12. The current sharing circuit according to claim 1, characterized in that, The current sharing circuit also includes multiple heat sinks, and the heat sinks and the current sharing module (400) are integrated into the same heat dissipation platform.

13. The current sharing circuit according to claim 12, characterized in that, The radiator is a copper tube radiator or a liquid-cooled radiator.

14. An energy storage system, characterized in that, include: The current sharing circuit according to any one of claims 1 to 13.

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