Modular integrated shock resistant circuit breaker

Abstract

The application belongs to the technical field of circuit breaker, and particularly relates to a modular integrated impact-resistant circuit breaker, which comprises a main flow-through circuit, a solid-state switch module and a current-limiting module; the main flow-through circuit comprises a series combination of a main inductor Lp and the solid-state switch module; the solid-state switch module is used for performing a breaking operation of the main flow-through circuit; and the current-limiting module is used for limiting a fault current peak value and reducing a breaking pressure of the solid-state switch. The solid-state switch module adopts a series design of multiple MOSFETs; each MOSFET is equipped with an independent driving unit and an overvoltage protection diode, thereby forming a complete multiple protection mechanism and a fault protection system of the circuit breaker; the current-limiting module based on the mutual inductance principle realizes the unification of active current limiting and passive protection; and the cooperation of a current-limiting branch and an energy consumption branch ensures effective absorption and safe release of the fault current.

Description

Technical Field

[0001] This invention belongs to the field of circuit breaker technology, specifically, it relates to a modular integrated impact-resistant circuit breaker. Background Technology

[0002] With the rapid development of new energy power systems, high-voltage DC power scenarios such as DC charging stations for new energy vehicles and DC combiner stations for photovoltaic power generation face challenges. Because DC power systems experience extremely rapid current rise after a fault, reaching tens of times the rated current within milliseconds, and the fault current lacks a natural zero-crossing point, disconnecting faulty circuits is difficult. Therefore, the performance requirements for circuit breakers are constantly increasing. Traditional mechanical circuit breakers, due to their inherent mechanical limitations, are no longer sufficient to meet the demands of high-voltage DC power systems in terms of response speed and high fault current withstand capability.

[0003] Existing solid-state circuit breakers typically employ a single high-power switching device or a simple parallel connection of devices. This design subjectes the switching devices to significant voltage and current stress, making them prone to damage. Furthermore, the lack of an effective current-limiting protection mechanism easily leads to current peaks during switching operations, severely impacting the reliability and lifespan of the solid-state switch.

[0004] Furthermore, in terms of fault detection, existing technologies mostly employ simple current threshold comparison methods, which are difficult to accurately distinguish between overcurrent faults and inrush currents. This coarse fault diagnosis method is prone to malfunctions, affecting the normal operation of the main circuit. Summary of the Invention

[0005] To address the lack of effective current-limiting protection mechanisms in existing solid-state circuit breakers and the technical problem of accurately distinguishing between overcurrent faults and inrush currents in fault detection, this invention provides a modular integrated impulse-resistant circuit breaker.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A modular integrated impact-resistant circuit breaker includes a main current circuit, a solid-state switch module, and a current-limiting module;

[0008] The main circuit consists of a series combination of the main inductor Lp and the solid-state switch module;

[0009] Solid-state switch modules are used to perform the disconnection operation of the main current circuit;

[0010] The current limiting module is used to limit the peak fault current and reduce the breaking pressure of the solid-state switch;

[0011] The solid-state switch module includes multiple MOSFET transistors connected in series, a first diode, and a driving unit; the source of each MOSFET transistor is connected to a series combination of a first diode and a voltage-limiting resistor to limit overvoltage; the driving unit includes a driving capacitor and a driving resistor; the gate of each MOSFET transistor is connected to a series combination of a driving capacitor and a driving resistor to provide driving charge.

[0012] The current limiting module includes a secondary inductor Ls, a current limiting branch, and a power dissipation branch; wherein, the main inductor Lp and the secondary inductor Ls have mutual inductance M; the current limiting branch and the power dissipation branch are connected in parallel with the secondary inductor Ls respectively;

[0013] The current-limiting branch includes a current-limiting resistor Rc and a current-limiting capacitor Cc, which are used to limit the amplitude of the fault current.

[0014] The energy-consuming branch includes a second diode and an energy-consuming resistor Re, which are used to absorb the remaining energy in the current-limiting module.

[0015] Preferably, the first diode is a TVS diode. When the drain-source voltage of the MOSFET transistor exceeds the clamping voltage of the TVS diode, the diode turns on, limiting the voltage within a safe range.

[0016] Preferably, the solid-state switch module further includes an MOV (metal oxide varistor) element, which is connected in parallel across the solid-state switch module. The MOV exhibits low impedance under normal voltage, and its impedance increases rapidly when the voltage exceeds its threshold, absorbing overvoltage energy.

[0017] Preferably, it also includes a monitoring module and a control module;

[0018] The monitoring module is used to acquire current signals in real time;

[0019] The control module is used to identify the frequency characteristics of the current signal according to the wavelet transform method, and then dynamically determine the fault type of the current signal through multiple thresholds, thereby generating the disconnection control logic of the solid-state switch module.

[0020] Preferably, the specific process for determining the fault type of the current signal in the control module includes:

[0021] The acquired current signal is preprocessed, including high-pass filtering;

[0022] The preprocessed current signal is decomposed using a wavelet transform algorithm. The db4 wavelet basis function is selected to perform a three-level discrete wavelet transform to obtain the fundamental component and the three-level detail components.

[0023] The three layers of detail components are high-frequency detail components, mid-frequency detail components, and low-frequency detail components, respectively.

[0024] The intermediate frequency detail component is selected as the overcurrent fault characteristic; the energy integral of the intermediate frequency detail component is calculated, and a current limiting threshold is preset based on it;

[0025] The calculation formula is as follows:

[0026]

[0027] In the formula, E represents the energy integral of the intermediate frequency detail component over the time interval [t1, t2]; D(t) represents the energy amplitude of the intermediate frequency detail component; t1 and t2 represent the start and end points of the integration time, respectively; dt represents the sampling time frequency.

[0028] The fault type is determined based on multiple different thresholds; the determination process is as follows:

[0029] When the detected rate of change of current exceeds the short-circuit threshold, it is considered a short-circuit fault.

[0030] If the energy integral of the detected intermediate frequency detail component exceeds the current limiting threshold and the duration exceeds the time threshold T, it is determined to be an overcurrent fault.

[0031] Preferably, the high-pass filtering process includes:

[0032] Select the filter type and set the filter parameters, including sampling rate, cutoff frequency, and order;

[0033] Calculate the filter coefficients using filter design tools;

[0034] The filter is deployed in the control module to output the filtered current signal.

[0035] Preferably, the specific process for generating the disconnection control logic of the solid-state switch module in the control module includes:

[0036] Adjust the value of the current limiting resistor Rc in the current limiting module according to the fault type. The current limiting resistor Rc is a variable resistor and its resistance value is adjusted by a digital potentiometer.

[0037] When a short circuit fault is detected, the control module sends a command to the digital potentiometer to adjust the current-limiting resistor Rc to the maximum resistance value and to perform a shutdown operation on the solid-state switch module.

[0038] When an overcurrent fault is detected, the resistance value of the current-limiting resistor Rc is gradually increased and delayed by T. If the current-limiting threshold is still exceeded, the solid-state switch module is shut down. If the current-limiting threshold is lower than the current-limiting threshold after a delay of T, no action is required.

[0039] Preferably, the circuit breaker's operation includes the following operating modes:

[0040] Mode I: The main current circuit is in normal conduction state, and the current flows through the main inductor Lp and the conducting solid-state switch module; no induced current is generated in the current limiting module because there is no fluctuation in the DC circuit; the control module continuously analyzes the current signal and does not trigger the disconnection control command.

[0041] Mode II: If the control module determines that a short circuit fault has occurred, the current limiting resistor Rc is adjusted to its maximum resistance value; the auxiliary inductor Ls in the current limiting module is coupled with the main inductor Lp to generate mutual inductance M, and the current limiting module shunts the current in the main current circuit through the current limiting branch to suppress the current peak of the main current circuit; at the same time, a disconnection control command for the solid-state switch is generated.

[0042] Mode III: If the control module determines that there is an overcurrent fault, the resistance value of the current limiting resistor Rc is gradually increased; the current limiting module continuously shunts the current in the main current circuit; at the same time, a disconnection control command for the solid-state switch is generated.

[0043] If the control module falls below the current limiting threshold after a delay T, it returns to Mode I.

[0044] Mode IV: The control module sends a disconnection control command, and the drive capacitor of the solid-state switch module provides power to disconnect all MOSFET transistors; when the main current circuit is disconnected, the transient fault current is transferred to the current limiting module.

[0045] Mode V: After the main current circuit is completely disconnected, the remaining energy in the current limiting module is completely released through the energy dissipation branch; the current in the secondary inductor Ls gradually decays to zero; the control module triggers a reset operation to return to Mode I.

[0046] The beneficial effects of this invention are:

[0047] 1. The impact-resistant circuit breaker proposed in this invention adopts a modular architecture, separating the main circuit module, solid-state switch module, and current-limiting module. Each module functions independently yet cooperates with each other, improving system reliability and maintainability; the modular design facilitates system upgrades and optimization, and the parameters of each module can be adjusted according to specific application requirements; at the same time, the modular structure helps reduce manufacturing costs and improve production efficiency.

[0048] 2. The solid-state switch module employs a series design of multiple MOSFETs; each MOSFET is equipped with an independent drive unit and overvoltage protection diode to ensure the reliability of switching operation. Furthermore, the parallel design of the MOV components provides additional overvoltage protection for the system, forming a complete multi-protection mechanism and fault protection system for the circuit breaker.

[0049] 3. The current limiting module based on the mutual inductance principle achieves a unified approach to active current limiting and passive protection. The mutual inductance between the main and auxiliary inductors enables the system to respond quickly to fault currents, while the coordination between the current limiting branch and the energy dissipation branch ensures the effective absorption and safe release of fault currents.

[0050] 4. A fault feature extraction method based on wavelet transform enables accurate differentiation between overcurrent and inrush current. Dynamically adjustable current-limiting resistors, combined with precise control logic, allow for differentiated handling of different fault types, improving the current-limiting effect and surge resistance of the circuit breaker. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is a circuit structure diagram of a modular integrated impact-resistant circuit breaker according to the present invention.

[0053] Figure 2 This is a circuit structure diagram of a solid-state switch module in a modular integrated impact-resistant circuit breaker according to the present invention.

[0054] Figure 3 This is a flowchart for determining the fault type in a modular integrated impact-resistant circuit breaker according to the present invention.

[0055] Figure 4 This is a flowchart of the generation and disconnection control logic in a modular integrated impact-resistant circuit breaker according to the present invention. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] Please see Figures 1-4 As shown, a modular integrated impact-resistant circuit breaker includes a main current circuit, a solid-state switch module, and a current limiting module.

[0058] The main circuit consists of a series combination of the main inductor Lp and the solid-state switch module;

[0059] Solid-state switch modules are used to perform the disconnection operation of the main current circuit;

[0060] The current limiting module is used to limit the peak fault current and reduce the breaking pressure of the solid-state switch;

[0061] The solid-state switch module includes multiple MOSFET transistors (Q1, Q2, Q3) connected in series, a first diode Tv, and a driving unit; the source of each MOSFET transistor is connected to a series combination of the first diode Tv and the voltage limiting resistor Rv to limit overvoltage; the driving unit includes a driving capacitor Ci and a driving resistor Ri; the gate of each MOSFET transistor is connected to a series combination of the driving capacitor Ci and the driving resistor to provide driving charge.

[0062] Specifically, the solid-state switching module employs a circuit design method that connects multiple MOSFET transistors (PN junction field-effect transistors) in series. Its core feature is that multiple MOSFET transistors connected in series share a single gate drive signal, rather than each MOSFET transistor having its own separate drive circuit. This design simplifies the drive circuit structure, reduces system complexity and cost, and, through a well-designed diode circuit, ensures dynamic voltage equalization among the multiple MOSFET transistors during switching.

[0063] As a preferred embodiment, the first diode Tv is a TVS diode. When the drain-source voltage of the MOSFET transistor exceeds the clamping voltage of the TVS diode, the diode conducts, limiting the voltage within a safe range.

[0064] During the operation of the solid-state switch module, when the gate drive signal is high, all series-connected MOSFET transistors turn on simultaneously, and current flows through the series path; the solid-state switch module is in the on state. When the gate drive signal is low, all MOSFET transistors turn off simultaneously. Due to the extremely fast turn-off speed of MOSFET transistors (microseconds), transient voltage unevenness can occur in the series circuit. At this time, through the series combination of a TVS diode with high breakdown voltage and instantaneous power and a current-limiting resistor, this TVS branch provides a current feedback loop, which can effectively clamp the drain-source voltage of the MOSFET transistors (Q2, Q3) and ensure the consistency of the sub-voltage distribution of each MOSFET transistor.

[0065] Therefore, the series-connected MOSFET transistor topology, through sharing the drive signal and optimizing the voltage equalization circuit, achieves efficient series connection of multiple MOSFET transistors, solving the dynamic voltage equalization problem in high-voltage DC scenarios. This makes it simple to design and fast to switch in medium- and high-voltage DC solid-state circuit breakers.

[0066] The current limiting module includes a secondary inductor Ls, a current limiting branch, and a power dissipation branch; wherein, the main inductor Lp and the secondary inductor Ls have mutual inductance M; the current limiting branch and the power dissipation branch are connected in parallel with the secondary inductor Ls respectively;

[0067] The current-limiting branch includes a current-limiting resistor Rc and a current-limiting capacitor Cc, which are used to limit the amplitude of the fault current.

[0068] The energy-consuming branch includes a second diode and an energy-consuming resistor Re, which are used to absorb the remaining energy in the current-limiting module.

[0069] Specifically, the modular integrated surge-resistant circuit breaker proposed in this invention combines a main current circuit, a solid-state switching module, and a current-limiting module. The current-limiting module works in conjunction with the solid-state switching module of the main current circuit through a secondary inductor Ls coupled to the main current circuit, a current-limiting branch, and an energy-dissipating branch. In the initial stage of a fault, the current-limiting module restricts the current rise in the main current circuit and shares energy during the disconnection process of the solid-state switching module, thereby protecting the main current circuit and accelerating fault clearing. The entire process requires no additional control measures and relies on the characteristics of the circuit itself.

[0070] During normal operation, the current ripple is small, and the coupled inductor does not generate induced voltage, meaning the independent current limiting module does not affect the normal operation of the main current-carrying circuit in the DC power grid. It is suitable for DC power scenarios such as DC charging stations for new energy vehicles and DC combiner stations for photovoltaic power generation.

[0071] When a fault occurs in a DC power scenario, the rapid rise of the main inductor current generates current fluctuations, which induce a voltage at the secondary inductor. This transfers energy to the current-limiting branch and the energy-consuming branch, thereby limiting the fault current.

[0072] In practical implementation, the mutual inductance M between the main inductor Lp and the secondary inductor Ls determines the strength of the coupling. A larger mutual inductance results in stronger coupling, higher energy transfer efficiency, and better current limiting. The turns ratio of the main / secondary inductors affects the magnitude of the induced voltage and current, therefore requiring careful design based on the specific application scenario. Furthermore, the design of the main / secondary inductors needs to be matched with the current-limiting resistor Rc and current-limiting capacitor Cc to ensure effective current limiting in the event of a fault.

[0073] Furthermore, the solid-state switch module also includes an MOV (metal oxide varistor) element, which is connected in parallel across the solid-state switch module. The MOV exhibits low impedance under normal voltage, and its impedance increases rapidly when the voltage exceeds its threshold, absorbing overvoltage energy.

[0074] Furthermore, it also includes a monitoring module and a control module;

[0075] The monitoring module is used to acquire current signals in real time;

[0076] The control module is used to identify the frequency characteristics of the current signal according to the wavelet transform method, and then dynamically determine the fault type of the current signal through multiple thresholds, thereby generating the disconnection control logic of the solid-state switch module.

[0077] In the specific implementation process, Hall effect sensors or fiber optic current sensors can be selected in the monitoring module, which are suitable for the acquisition of low-to-medium frequency DC waveform signals.

[0078] The control module can utilize an FPGA embedded processor, which possesses high-speed and parallel computing capabilities, making it suitable for real-time wavelet transform signal processing. Specifically, the PL (Programmer) side implements the wavelet transform algorithm and threshold decision logic, while the PS (Power Supply) side executes the control logic and communication protocol.

[0079] Specifically, the monitoring and control modules aim to achieve rapid fault detection and accurate fault diagnosis through high-precision sensing, real-time signal processing, and intelligent control logic. Their implementation encompasses hardware design, communication protocols, and control logic optimization, ensuring the system's reliability and real-time performance under complex operating conditions, and providing core technical support for modular integrated impulse-resistant circuit breakers. In this technical field, hardware design and communication protocols are conventional technologies and have been publicly referenced, therefore they will not be described in detail. Only the control logic optimization aspect is specifically elaborated below.

[0080] Furthermore, the specific process for determining the fault type of the current signal in the control module includes:

[0081] The acquired current signal is preprocessed, including high-pass filtering;

[0082] The preprocessed current signal is decomposed using a wavelet transform algorithm. The db4 wavelet basis function is selected to perform a three-level discrete wavelet transform to obtain the fundamental component and the three-level detail components.

[0083] The three layers of detail components are high-frequency detail components, mid-frequency detail components, and low-frequency detail components, respectively.

[0084] The intermediate frequency detail component is selected as the overcurrent fault characteristic; the energy integral of the intermediate frequency detail component is calculated, and a current limiting threshold is preset based on it;

[0085] The calculation formula is as follows:

[0086]

[0087] In the formula, E represents the energy integral of the intermediate frequency detail component over the time interval [t1, t2]; D(t) represents the energy amplitude of the intermediate frequency detail component; t1 and t2 represent the start and end points of the integration time, respectively; dt represents the sampling time frequency.

[0088] The fault type is determined based on multiple different thresholds; the determination process is as follows:

[0089] When the detected rate of change of current exceeds the short-circuit threshold, it is considered a short-circuit fault.

[0090] If the energy integral of the detected intermediate frequency detail component exceeds the current limiting threshold and the duration exceeds the time threshold T, it is determined to be an overcurrent fault.

[0091] Specifically, in the decision-making process of the control module, the acquired current signal is first preprocessed with a high-pass filter; this eliminates DC components and low-frequency interference, improves the signal-to-noise ratio, and provides clearer signal characteristics for subsequent wavelet analysis. A three-level discrete wavelet transform is performed using the db4 wavelet basis function. The db4 wavelet basis has good frequency localization characteristics; it exhibits tight support in both the time and frequency domains; and vanishing moments are used to extract signal singularities. Thus, the signal is divided into: a fundamental component, reflecting the main trend of the signal, through three-level wavelet decomposition.

[0092] High-frequency detail components: reflect rapidly changing information (short-circuit faults);

[0093] Mid-frequency detail components: reflect the characteristics of overcurrent faults;

[0094] Low-frequency detail components: reflect the fluctuation characteristics of signal interference;

[0095] Since the direct current threshold method struggles to distinguish between fault types such as overcurrent and inrush current, a multi-band feature extraction method using wavelet transform is employed. The mid-frequency detail components are less affected by high-frequency variations and low-frequency noise fluctuations, best reflecting the characteristics of overcurrent faults. Energy integration of the mid-frequency detail components reflects the energy accumulation characteristics of the fault. By setting a current-limiting threshold and a time threshold T that conform to the energy accumulation of DC power scenarios, a reliable overcurrent fault judgment logic is established, achieving accurate differentiation between overcurrent and inrush current. This provides a targeted and dynamically adaptive judgment standard for dynamic load scenarios such as DC systems.

[0096] Short circuit faults are determined by monitoring the rate of change of current di / dt and comparing it with the short circuit threshold (e.g., di / dt > 10^3 A / s). If the current exceeds the short circuit threshold, it can be determined as a short circuit fault.

[0097] Furthermore, the high-pass filtering process includes:

[0098] Select the filter type and set the filter parameters, including sampling rate, cutoff frequency, and order;

[0099] Calculate the filter coefficients using filter design tools;

[0100] The filter is deployed in the control module to output the filtered current signal.

[0101] In practical implementation, a Butterworth filter can be selected, as it has the most flat passband characteristic. Key parameter settings include:

[0102] Determining the sampling rate fs: According to the Nyquist sampling theorem, the sampling rate should be at least twice the highest frequency of the signal. Considering the margin in practical applications, the sampling rate is set to 6-10 times the highest frequency.

[0103] Selection of cutoff frequency fc: The cutoff frequency should be determined based on the low-frequency components that need to be filtered out and the useful signal frequencies that need to be retained. The cutoff frequency can be set in the range of 0.5-1 times the power frequency.

[0104] Determining the filter order n: The filter order directly affects the filtering effect and computational complexity. A higher order results in better filtering, but also increases the computational load. Typically, orders between 4 and 6 are chosen to strike a balance between filtering effectiveness and computational efficiency.

[0105] Through reasonable parameter settings and optimization measures, this high-pass filter preprocessing step can effectively remove DC components and low-frequency interference, providing a reliable signal basis for subsequent fault detection.

[0106] Furthermore, the specific process for generating the disconnection control logic of the solid-state switch module in the control module includes:

[0107] Adjust the value of the current limiting resistor Rc in the current limiting module according to the fault type. The current limiting resistor Rc is a variable resistor and its resistance value is adjusted by a digital potentiometer.

[0108] When a short circuit fault is detected, the control module sends a command to the digital potentiometer to adjust the current-limiting resistor Rc to the maximum resistance value and to perform a shutdown operation on the solid-state switch module.

[0109] When an overcurrent fault is detected, the resistance value of the current-limiting resistor Rc is gradually increased and delayed by T. If the current-limiting threshold is still exceeded, the solid-state switch module is shut down. If the current-limiting threshold is lower than the current-limiting threshold after a delay of T, no action is required.

[0110] In practical implementation, the resistance value of the current-limiting resistor Rc is based on the dynamic adjustment mechanism of the digital potentiometer. By adjusting the resistance value of the current-limiting resistor Rc in real time, different types of faults can be addressed. The core of the system lies in adopting differentiated control strategies according to the fault type, achieving rapid response to short-circuit faults and gradual handling of overcurrent faults.

[0111] When a short-circuit fault is detected, the control module immediately performs two key operations. First, it sends a control command to the digital potentiometer to adjust the current-limiting resistor Rc to its preset maximum resistance value. This operation can limit the increase of the fault current in the shortest possible time. Second, it simultaneously triggers the shutdown operation of the solid-state switch module to quickly isolate the faulty circuit. This dual protection mechanism can effectively prevent equipment damage caused by short-circuit faults.

[0112] When an overcurrent fault is detected, the system employs a gradual control strategy. The control module first incrementally increases the resistance value of the current-limiting resistor Rc, reducing the current level through fine-tuning of the resistance. After each adjustment, the system waits for a preset time period T. This delay allows the system to observe the adjustment effect and avoids excessive intervention. If the current still exceeds the current-limiting threshold after the delay T, the system will then execute the circuit breaker's shutdown operation. This strategy ensures reliable system operation while avoiding unnecessary power outages.

[0113] Meanwhile, the setting of the time threshold T is a key factor in system performance. This parameter needs to comprehensively consider the system's electrical time constant, load characteristics, and protection requirements. Too short a delay may lead to over-response, while too long a delay may affect the protection effect. The optimal delay parameter can be determined through experimental verification and theoretical analysis.

[0114] This control logic scheme, through reasonable process design and parameter configuration, achieves accurate identification and differentiated handling of different types of faults, providing a strong guarantee for the reliable operation of circuit breakers.

[0115] In a more preferred implementation, the control of a digital potentiometer requires quantifying the resistance value of each adjustment step to ensure that the adjustment step size meets the control requirements without causing system oscillation. Simultaneously, the response characteristics and adjustment accuracy of the digital potentiometer must also match the system requirements to ensure that control commands are executed accurately.

[0116] Furthermore, the circuit breaker's operation includes the following operating modes:

[0117] Mode I: The main current circuit is in normal conduction state, and the current flows through the main inductor Lp and the conducting solid-state switch module; no induced current is generated in the current limiting module because there is no fluctuation in the DC circuit; the control module continuously analyzes the current signal and does not trigger the disconnection control command.

[0118] Mode II: If the control module determines that a short circuit fault has occurred, the current limiting resistor Rc is adjusted to its maximum resistance value; the auxiliary inductor Ls in the current limiting module is coupled with the main inductor Lp to generate mutual inductance M, and the current limiting module shunts the current in the main current circuit through the current limiting branch to suppress the current peak of the main current circuit; at the same time, a disconnection control command for the solid-state switch is generated.

[0119] Mode III: If the control module determines that there is an overcurrent fault, the resistance value of the current limiting resistor Rc is gradually increased; the current limiting module continuously shunts the current in the main current circuit; at the same time, a disconnection control command for the solid-state switch is generated.

[0120] If the control module falls below the current limiting threshold after a delay T, it returns to Mode I.

[0121] Mode IV: The control module sends a disconnection control command, and the drive capacitor Ci of the solid-state switch module provides power to disconnect all MOSFET transistors; when the main current circuit is disconnected, the transient fault current is transferred to the current limiting module.

[0122] Mode V: After the main current circuit is completely disconnected, the remaining energy in the current limiting module is completely released through the energy dissipation branch; the current in the secondary inductor Ls gradually decays to zero; the control module triggers a reset operation to return to Mode I.

[0123] In summary, the impact-resistant circuit breaker proposed in this invention adopts a modular architecture, functionally separating the main circuit module, solid-state switch module, and current-limiting module. Each module functions independently yet cooperates with each other, improving system reliability and maintainability. The modular design facilitates system upgrades and optimization, allowing adjustment of module parameters according to specific application requirements. Simultaneously, the modular structure helps reduce manufacturing costs and improve production efficiency. The solid-state switch module employs a multi-MOSFET series design, with each MOSFET equipped with an independent drive unit and overvoltage protection diode, ensuring reliable switching operation. The current-limiting module, based on the mutual inductance principle, achieves a unified approach to active current limiting and passive protection, ensuring effective absorption and safe release of fault current.

[0124] Furthermore, a fault feature extraction method based on wavelet transform enables accurate differentiation between overcurrent and inrush current. Dynamically adjustable current-limiting resistors, combined with precise control logic, allow for differentiated handling of different fault types. This improves the current-limiting effect and surge resistance of the circuit breaker, providing new technical support and application methods for the development of next-generation high-voltage DC circuit breakers.

[0125] In the description of this specification, the terms "in practice," "further," "specifically," etc., refer to specific features, structures, materials, or characteristics described in connection with the embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0126] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A modular integrated impact-resistant circuit breaker, characterized in that: This includes mainstream circuits, solid-state switching modules, and current limiting modules; The main circuit consists of a series combination of the main inductor and the solid-state switch module; Solid-state switch modules are used to perform the disconnection operation of the main current circuit; The current limiting module is used to limit the peak fault current and reduce the breaking pressure of the solid-state switch; The solid-state switch module includes multiple MOSFET transistors connected in series, a first diode, and a drive unit; The MOSFET transistor includes a first transistor and a plurality of second transistors connected in series, wherein the drain of the first transistor is connected to the source of the second transistors; One end of the series combination of the first diode and the voltage-limiting resistor is connected to the drain of the second transistor, and the other end is connected to the source of the first transistor. The driving unit includes a driving capacitor and a driving resistor; one end of the driving resistor is connected to the gate of the second transistor, the other end of the driving resistor is connected to one end of the driving capacitor and the other end of the series combination of the first diode and the voltage limiting resistor, and the other end of the driving capacitor is connected to the source of the first transistor. The current limiting module includes a secondary inductor, a current limiting branch, and a power dissipation branch; the primary inductor and the secondary inductor are mutually inductant; the current limiting branch and the power dissipation branch are connected in parallel with the secondary inductor, respectively. The current-limiting branch includes a current-limiting resistor and a current-limiting capacitor connected in series, used to limit the amplitude of the fault current; The energy-consuming branch includes a second diode and an energy-consuming resistor connected in series, which are used to absorb the remaining energy in the current-limiting module.

2. The modular integrated impact-resistant circuit breaker according to claim 1, characterized in that: The first diode is a TVS diode. When the drain-source voltage of the MOSFET transistor exceeds the clamping voltage of the TVS diode, the diode turns on, limiting the voltage within a safe range.

3. The modular integrated impact-resistant circuit breaker according to claim 1, characterized in that: The solid-state switch module also includes an MOV element, which is connected in parallel across the two ends of the solid-state switch module. The MOV exhibits low impedance under normal voltage, and its impedance increases rapidly when the voltage exceeds its threshold, absorbing overvoltage energy.

4. A modular integrated impact-resistant circuit breaker according to claim 1, characterized in that, It also includes a monitoring module and a control module; the monitoring module is used to acquire current signals in real time; the control module is used to identify the frequency characteristics of the current signal according to the wavelet transform method, and then dynamically determine the fault type of the current signal through multiple thresholds, thereby generating the disconnection control logic of the solid-state switch module.

5. A modular integrated impact-resistant circuit breaker according to claim 4, characterized in that, The specific process for determining the fault type of the current signal in the control module includes: The acquired current signal is preprocessed, including high-pass filtering; The preprocessed current signal is decomposed using a wavelet transform algorithm. The db4 wavelet basis function is selected to perform a three-level discrete wavelet transform to obtain the fundamental component and three levels of detail components. The three levels of detail components are high-frequency detail components, mid-frequency detail components, and low-frequency detail components, respectively. The intermediate frequency detail component is selected as the overcurrent fault characteristic; the energy integral of the intermediate frequency detail component is calculated, and a current limiting threshold is preset based on it; The fault type is determined based on multiple different thresholds; the determination process is as follows: When the detected rate of change of current exceeds the short-circuit threshold, it is considered a short-circuit fault. If the energy integral of the detected intermediate frequency detail component exceeds the current limiting threshold and the duration exceeds the time threshold T, it is determined to be an overcurrent fault.

6. A modular integrated impact-resistant circuit breaker according to claim 5, characterized in that, The formula for calculating the energy integral of the mid-frequency detail component is as follows: ； In the formula, This represents the energy integral of the mid-frequency detail components over the time interval [t2, t1]. t1 represents the energy amplitude of the mid-frequency detail component; t2 and t1 represent the start and end points of the integration time, respectively. This indicates the sampling time frequency.

7. A modular integrated impact-resistant circuit breaker according to claim 5, characterized in that, The high-pass filtering process includes: Select the filter type and set the filter parameters, including sampling rate, cutoff frequency, and order; Calculate the filter coefficients using filter design tools; The filter is deployed in the control module to output the filtered current signal.

8. A modular integrated impact-resistant circuit breaker according to claim 4, characterized in that, The specific process of generating the disconnection control logic of the solid-state switch module in the control module includes: Adjust the value of the current limiting resistor Rc in the current limiting module according to the fault type. The current limiting resistor Rc is a variable resistor and its resistance value is adjusted by a digital potentiometer. When a short circuit fault is detected, the control module sends a command to the digital potentiometer to adjust the current-limiting resistor Rc to the maximum resistance value and to perform a shutdown operation on the solid-state switch module. When an overcurrent fault is detected, the resistance value of the current-limiting resistor Rc is gradually increased and delayed by T. If the current-limiting threshold is still exceeded, the solid-state switch module is shut down. If the current-limiting threshold is lower than the current-limiting threshold after a delay of T, no action is required.

9. A modular integrated impact-resistant circuit breaker according to any one of claims 4-8, characterized in that: The circuit breaker operates in the following modes: Mode I: The main current-carrying loop is in normal conduction state, and the current flows through the main inductor Lp and the conducting solid-state switch module; No induced current was generated in the current limiting module because there was no fluctuation in the DC circuit; the control module continuously analyzed the current signal but did not trigger the disconnection control command. Mode II: If the control module determines that a short circuit fault has occurred, the current limiting resistor Rc is adjusted to its maximum resistance value; the auxiliary inductor Ls in the current limiting module is coupled with the main inductor Lp to generate mutual inductance M, and the current limiting module shunts the current in the main current circuit through the current limiting branch to suppress the current peak of the main current circuit; at the same time, a disconnection control command for the solid-state switch is generated. Mode III: If the control module determines that there is an overcurrent fault, the resistance value of the current limiting resistor Rc is gradually increased; the current limiting module continuously shunts the current in the main current circuit; at the same time, a disconnection control command for the solid-state switch is generated. If the control module falls below the current limiting threshold after a delay T, it returns to Mode I. Mode IV: The control module sends a disconnection control command, and the drive capacitor of the solid-state switch module provides power to disconnect all MOSFET transistors; when the main current circuit is disconnected, the transient fault current is transferred to the current limiting module. Mode V: After the main current loop is completely disconnected, the remaining energy in the current limiting module is completely released through the energy dissipation branch; The current in the secondary inductor Ls gradually decays to zero; the control module triggers a reset operation and returns to Mode I.

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