SiC-based integrated aviation bidirectional solid-state circuit breaker and control protection method

Abstract

The application discloses a SiC-based integrated aviation bidirectional solid-state circuit breaker and a control protection method, and belongs to the technical field of SiC power semiconductor control. The application comprises a SiC common-source bidirectional power module and a full-digital control component; the SiC common-source bidirectional power module adopts a SiC power semiconductor device array common-source symmetric bidirectional topological structure to form a bidirectional symmetric conduction main power control switch; the full-digital control component is electrically isolated and connected with the SiC common-source bidirectional power module; the full-digital control component comprises a DSP processor unit, a switching value interface unit and a SiC module isolation driving unit; the DSP processor unit is connected with the switching value interface unit; the switching value interface unit and the SiC module isolation driving unit establish a control link to directly control the on-off of the SiC common-source bidirectional power module through the SiC module isolation driving unit. The application is specially used for aviation high-voltage direct-current power supply and distribution and electric aircraft power grid configuration conversion, and has high integration degree and high reliability.

Description

Technical Field

[0001] This invention belongs to the field of aviation electrical system technology, and relates to an integrated aviation bidirectional solid-state circuit breaker based on SiC and its control and protection method. Background Technology

[0002] With the rapid development of more-electric aircraft and electric aviation technology, high-voltage direct current (HVDC) power distribution systems have become the mainstream configuration for airborne power supply and distribution systems. Solid-state circuit breakers, as core components for fault isolation and on / off control, are key equipment for ensuring the safe operation of aviation electrical systems. In aviation HVDC applications, solid-state circuit breakers not only need to handle the on / off control of conventional circuits, but also need to adapt to harsh airborne operating conditions such as bidirectional energy flow, high power density, and strong electromagnetic interference.

[0003] A search of existing publicly available patents and academic papers reveals that existing solid-state circuit breakers suffer from core technological defects and are unsuitable for the harsh operating conditions of airborne aviation: First, bidirectional topologies are mostly asymmetrical structures with inconsistent bidirectional current-carrying electrical characteristics, failing to meet the bidirectional energy flow requirements of electric aircraft, and lacking aviation-specific common-source symmetrical topologies; Second, they rely on external magnetic current sensors or shunts, resulting in large size, susceptibility to magnetic saturation, low power density, and lack of built-in integrated shunt detection design; Third, they lack processor-based fully digital closed-loop control, bus and hardwired dual redundancy design, and programmable inverse-time overload protection; Fourth, they lack aviation-specific optimization, do not support grid configuration conversion, and lack fully isolated anti-interference design; Fifth, their simple topologies and low integration fail to meet the integrated design requirements of aviation high-voltage systems.

[0004] Existing high-current SiC modules are mostly half-bridge or full-bridge types. More importantly, they lack an integrated current acquisition unit, requiring external integration, and lack fully digital control components. The control box protection method is singular, and it requires external processor units and functional circuits for implementation. Therefore, there is an urgent need for a highly integrated and highly independent architecture suitable for aviation DC high-voltage and high-power scenarios to address the shortcomings of existing technologies in terms of rapid switching of high-voltage power grid power supply configurations, rapid fault diagnosis, system integration, lightweighting, digitalization, and control redundancy. Summary of the Invention

[0005] The purpose of this invention is to provide an integrated aviation bidirectional solid-state circuit breaker based on SiC and a control and protection method to overcome the shortcomings of existing technologies in terms of topological symmetry, detection integration, control redundancy and scenario adaptability.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an integrated aerospace bidirectional solid-state circuit breaker based on SiC, comprising: The SiC common-source bidirectional power module adopts a common-source symmetrical bidirectional topology structure of SiC power semiconductor device array to form a bidirectional symmetrically conducting main power control switch; the SiC common-source bidirectional power module integrates an integrated shunt detection unit, which is connected in series in the main power circuit to convert the bidirectional current signal of the main power circuit; The fully digital control component is electrically isolated from the SiC common-source bidirectional power module. The fully digital control component includes a DSP processor unit, a digital input interface unit, and a SiC module isolation drive unit. The DSP processor unit is connected to the digital input interface unit to acquire the status of digital input signals. The digital input interface unit establishes a control link with the SiC module isolation drive unit and directly controls the on / off state of the SiC common-source bidirectional power module through the SiC module isolation drive unit.

[0007] Furthermore, the SiC common-source bidirectional power module includes two groups of SiC power semiconductor device arrays, A and B, and an integrated shunt detection unit. Group A consists of N SiC MOSFET chips connected in parallel for current amplification. The drains (D) and sources (S) of all SiC MOSFET chips are connected together. Each SiC MOSFET chip's source (S) has a separate control loop connection terminal (KS), which, together with the gate, serves as the common control terminals G_A and KS_A for the group A chip array. Group B consists of the same number of SiC MOSFET chips connected in parallel as group A, with a symmetrical chip layout. All SiC MOSFET chips in group B... The drain (D) and source (S) connections of the MOSFET chip are the same as those of group A. The common control terminals of the group B chip array are G_B and KS_B. The source of the group A array is connected to the source of the group B array. The drain of the group A array is connected to the power supply input or output interface. The drain of the group B array is connected to one end of the integrated shunt detection unit. The other end of the integrated shunt detection unit is connected to the power supply output or input interface, forming a complete bidirectional main power loop.

[0008] Furthermore, the all-digital control component also includes a CAN bus interface unit, which, together with the digital input / output interface unit, forms a dual-redundant control architecture. The CAN bus interface unit is used to realize remote command interaction and device status uploading. The digital input / output interface unit is an opto-isolated hard-wired interface used to realize emergency on / off control.

[0009] Furthermore, the all-digital control component also includes a protection and discharge circuit unit, which is connected in parallel across the input / output terminals of the main power circuit to suppress transient overvoltages in the power circuit and discharge fault energy.

[0010] Furthermore, the all-digital control component also includes a voltage isolation acquisition unit and a current isolation acquisition unit; the voltage isolation acquisition unit is used to isolate and acquire the high voltage signal of the main power circuit, and the current isolation acquisition unit is used to isolate and acquire the current signal of the integrated shunt detection unit; the DSP processor unit is connected to the voltage isolation acquisition unit and the current isolation acquisition unit respectively to receive the acquired signals.

[0011] Furthermore, the all-digital control assembly also includes a power supply circuit unit; the power supply circuit unit adopts a non-isolated and isolated power supply conversion topology to convert the external input voltage into non-isolated and isolated power supplies, respectively supplying power to each low-voltage side and high-voltage side unit in the all-digital control assembly.

[0012] Furthermore, the circuit breaker supports bidirectional power flow, adapting to the charging and discharging of electric aircraft energy storage systems, energy feedback of propulsion systems, and flexible switching of multi-bus grid configurations.

[0013] Furthermore, the circuit breaker's switching process adopts a PWM linear step-type soft-connection control method, with its PWM duty cycle configurable within the range of 10% to 100%, and the PWM frequency and soft-connection time configurable.

[0014] Furthermore, the integrated aviation bidirectional solid-state circuit breaker is equipped with three independent protection mechanisms, including: I²t inverse time protection based on the DSP processor unit; microsecond-level short-circuit protection determined by hardware circuitry and controlled by the DSP processor unit; and SiC driver desaturation protection directly detected and blocked by hardware circuitry.

[0015] Secondly, the present invention provides a control and protection method for an integrated aerospace bidirectional solid-state circuit breaker based on SiC, comprising the following steps: It provides SiC common-source bidirectional power modules and fully digital control components, which are electrically isolated from each other. The DSP processor unit in the all-digital control assembly acquires and processes the voltage and current signals of the main power circuit in real time; During normal operation, the DSP processor unit responds to CAN bus commands or hard-wired digital commands and controls the on / off state of the SiC common-source bidirectional power module through the SiC module isolation drive unit. At the same time, external digital signals can control the SiC common-source bidirectional power module to be turned on directly through the independent control link between the digital interface unit and the SiC module isolation drive unit without going through the DSP processor unit. Under fault conditions, the circuit breaker implements a triple independent protection mechanism: the DSP processor unit performs I²t inverse time protection based on the real-time current signal, dynamically adjusting the breaking timing; when a short circuit occurs, microsecond-level short circuit protection is implemented, with the hardware circuit determining the short circuit state and the DSP processor unit controlling rapid breaking; when desaturation of the SiC power device is detected, SiC driver desaturation protection is implemented, with the hardware circuit directly detecting and immediately blocking the drive signal, achieving device-level nanosecond-level protection.

[0016] Compared with the prior art, the present invention has the following technical effects: This invention employs a SiC power semiconductor device array with a common-source symmetrical bidirectional topology, enabling the formation of a bidirectional symmetrically conducting main power control switch. This achieves complete symmetry in the forward and reverse current flow paths, impedance, and electrical characteristics, meeting the bidirectional energy flow requirements of the aerospace field. By integrating the integrated shunt detection unit within the SiC common-source bidirectional power module and connecting it in series in the main power circuit for converting the bidirectional current signal of the main power circuit, the external magnetic current sensor or shunt can be eliminated, avoiding magnetic saturation defects and significantly improving the power density and detection stability of airborne equipment. By setting up fully digital control components and electrically isolating them from the SiC common-source bidirectional power module, complete electrical isolation between the high-voltage power circuit and the low-voltage control circuit can be achieved, improving the anti-interference capability in complex electromagnetic environments of aviation. By setting up a switch interface unit to establish a control link with the SiC module isolation drive unit and directly control the on / off state of the SiC common-source bidirectional power module, and connecting the DSP processor unit to the switch interface unit to collect the status of switch signals, a dual-redundant control architecture of DSP processor control and hard-wired direct drive of switch signals can be constructed. Even if the DSP processor unit fails, the external switch signals can still independently control the on / off state of the circuit breaker, greatly improving control reliability and task execution capability.

[0017] In summary, the SiC-based integrated bidirectional solid-state circuit breaker provided by this invention is particularly suitable for applications with extremely high requirements for equipment power density, control reliability, and safety, such as aviation high-voltage DC power supply and distribution and electric aircraft power grid configuration conversion. Attached Figure Description

[0018] Figure 1 is a block diagram of the circuit topology of the intelligent solid-state circuit breaker according to an embodiment of the present invention.

[0019] Figure 2 is a core circuit topology diagram of the SiC common-source bidirectional power module according to an embodiment of the present invention.

[0020] Figure 3 is a composite protection logic diagram of the intelligent solid-state circuit breaker according to an embodiment of the present invention. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1, referring to Figure 1, in one embodiment of the present invention, provides an integrated aviation bidirectional solid-state circuit breaker based on SiC, mainly targeting high-voltage grid conversion and control of electric aircraft, high-power power distribution control, and other power control scenarios with anti-reverse current. Based on a highly integrated high-power intelligent solid-state power control and protection device with symmetrical common-source bidirectional topology SiC, it emphasizes safety, reliability, and adaptability to complex loads (including triple-combination protection mode, redundancy control, and PWM linear step soft turn-on), solving the pain points of current aviation high-voltage DC power supply and distribution systems.

[0022] This circuit breaker is used in the conversion of aviation high-voltage DC power supply and distribution systems to electric aircraft grid power supply configurations and in high-power power distribution control. It aims to solve the shortcomings of existing solid-state circuit breakers in terms of topological symmetry, detection integration, control redundancy and aviation adaptability, and to provide an integrated solution with high power density, high reliability and fully digital intelligent protection capabilities.

[0023] Specifically, the integrated SiC-based bidirectional solid-state circuit breaker of this invention comprises the following components: The SiC common-source bidirectional power module adopts a common-source symmetrical bidirectional topology structure of SiC power semiconductor device array to form a bidirectional symmetrically conducting main power control switch; the SiC common-source bidirectional power module integrates an integrated shunt detection unit, which is connected in series in the main power circuit to convert the bidirectional current signal of the main power circuit; A fully digital control component is electrically isolated from the SiC common-source bidirectional power module. The fully digital control component includes a DSP processor unit, a digital input / output interface unit, and a SiC module isolation drive unit. The DSP processor unit is connected to the digital input / output interface unit to acquire the status of digital input / output signals. The digital input / output interface unit establishes a control link with the SiC module isolation drive unit and directly controls the on / off state of the SiC common-source bidirectional power module through the SiC module isolation drive unit.

[0024] The SiC common-source bidirectional power module employs a common-source symmetrical bidirectional topology for SiC power semiconductor device arrays. This common-source symmetrical bidirectional topology means that the module contains two sets of power semiconductor devices. The sources of the two sets of devices are electrically connected together to form a common node, while the drains of the two sets of devices serve as two power ports for external circuit breaker connections. This topology fundamentally ensures that regardless of which port the current flows into or out from, the number of semiconductor devices it passes through, the path impedance, and the electrical stress distribution are exactly the same. This constitutes a bidirectional symmetrically conducting main power control switch, perfectly suited for bidirectional energy flow conditions such as charging and discharging in electric aircraft energy storage systems and energy feedback in propulsion systems. The module is presented as a highly integrated semi-open package, facilitating electrical and structural integration with fully digital control components.

[0025] The integrated shunt detection unit is designed to be integrated within the SiC common-source bidirectional power module. The shunt detection unit is connected in series in the main power circuit. When bidirectional load current flows through this resistor, according to Ohm's law, a weak voltage signal proportional to the current magnitude is generated across it. This voltage signal is the direct conversion of the bidirectional current signal in the main power circuit, which is then acquired and processed. This built-in approach eliminates the installation space and additional wiring required by external current sensors, and avoids the problems of magnetic saturation and measurement distortion that easily occur with traditional magnetic sensors in environments with aerospace vibration, high temperatures, and strong electromagnetic interference, significantly improving the long-term stability and reliability of current detection.

[0026] Electrical isolation is maintained between the all-digital control components and the SiC common-source bidirectional power modules. This electrical isolation means there is no direct electrical loop between the high-voltage and low-voltage sides; signal and energy transmission is achieved through magnetic coupling, optical coupling, or capacitive coupling. This completely eliminates the risk of high-voltage fault voltage affecting the low-voltage control circuits and personnel, ensuring system safety. Inside the all-digital control components, the DSP processor unit is the core control hub, integrating analog-to-digital conversion, PWM output, and communication peripherals. It performs signal processing, algorithm calculations, instruction execution, and status management, constructing a fully digital closed-loop control system.

[0027] A control link is established between the digital input / output interface unit and the SiC module isolation driver unit. The digital input / output interface unit is designed as an opto-isolated hardwired interface. Its output control signal is acquired by the DSP processor unit for status monitoring and logic integration; simultaneously, this signal is physically connected directly to the enable or input terminal of the SiC module isolation driver unit, forming an independent control link that does not pass through the DSP processor unit. Therefore, even in the most extreme case of a complete failure of the DSP processor unit, the pilot or upper control system can still directly command the SiC module isolation driver unit to activate by closing the external hardwired digital input / output signal, forcibly turning on or off the main power circuit. This greatly improves the system's mission reliability and control robustness in critical situations.

[0028] This invention presents an integrated SiC-based aerospace bidirectional solid-state circuit breaker architecture. By integrating a SiC common-source bidirectional power module with a common-source polarity symmetrical bidirectional topology, an internally integrated shunt detection unit, and a fully digital control component with dual-redundant control links, a complete closed-loop system is formed, encompassing power execution, intelligent control, and redundancy protection. The collaborative operation of these components ensures both bidirectional current carrying capacity and power density, while achieving comprehensive control reliability coverage from the core processor to the hardwired interface. This provides a simple, powerful, and extremely reliable solid-state power distribution protection solution for aerospace high-voltage DC power distribution applications.

[0029] The SiC common-source bidirectional power module includes two groups of SiC power semiconductor device arrays, A and B, and an integrated shunt detection unit. Group A consists of N SiC MOSFET chips connected in parallel for current amplification. The drains (D) and sources (S) of all SiC MOSFET chips are connected together. Each SiC MOSFET chip's source (S) has a separate control loop connection terminal (KS), which, together with the gate, serves as the common control terminals G_A and KS_A for the group A chip array. Group B consists of the same number of SiC MOSFET chips connected in parallel as group A. The chip layout is symmetrical to group A. The drains (D) and sources (S) of all SiC MOSFET chips in group B are connected in the same way as group A. The common control terminals for group B are G_B and KS_B. The sources of group A and group B are connected. The drains of group A are connected to the power supply input or output interface. The drain of the array is connected to one end of the integrated shunt detection unit, and the other end of the integrated shunt detection unit is connected to the power supply output or input interface, forming a complete bidirectional main power circuit.

[0030] Referring to Figure 2, Group A consists of N SiC MOSFET chips connected in parallel to amplify current. By merging the drains (D) and sources (S) of multiple power chips, the total current flowing through them is evenly distributed among the chips, thus multiplying the current capacity. Simultaneously, to ensure that all parallel chips can turn on and off synchronously and consistently, the gates (G) of all chips must also be merged to form a unified control terminal. Furthermore, in addition to being part of the power loop, the source also has a lead called the control loop connection terminal (KS), commonly known as a Kelvin source connection. Its purpose is to provide an independent reference potential for the gate drive signal, unaffected by the voltage drop of the large current loop, ensuring accurate and stable drive voltage during high-speed switching. After all chips are connected in parallel, the unified gate common terminal G_A and the source control common terminal KS_A together constitute the control port of the Group A chip array, receiving drive signals from the SiC module's isolated drive unit.

[0031] The structure of the SiC power semiconductor device array in group B is exactly the same as that in group A, consisting of N SiC MOSFET chips connected in parallel. The connection of its drain (D) and source (S), as well as the formation of the control terminals G_B and KS_B, are identical to those in group A. The key topological connection between the two groups is that the sources of the group A array and the group B array are directly connected together, forming a common-source node. This common-source node is the physical basis for bidirectional functionality. When current flows from the drain of group A to the drain of group B, the current path is: group A MOSFET drain → group A MOSFET channel → group A MOSFET source (common-source node) → group B MOSFET source → group B MOSFET channel → group B drain. When the current direction is opposite, the path is completely symmetrical. The drain of group A serves as the power input (or output) interface, while the drain of group B is connected to one end of an integrated shunt detection unit, the other end of which serves as the power output (or input) interface. In this embodiment, by placing the integrated shunt detection unit between the drain of group B and the external port, the current flowing through the integrated shunt detection unit is always the total current of the complete loop, regardless of the current direction, ensuring the accuracy and consistency of bidirectional current detection. The symmetrical chip layout ensures uniform heat distribution between the two groups of chips during operation, improving the long-term reliability of the device. This embodiment constructs a complete and perfectly symmetrical bidirectional main power loop from the external port, through group A devices, the common source node, group B devices, to the integrated shunt detection unit, and finally to the other external port, providing a practical hardware foundation for bidirectional current flow and high integration of the circuit breaker.

[0032] The all-digital control component also includes a CAN bus interface unit, which, together with the digital input / output interface unit, forms a dual-redundant control architecture. The CAN bus interface unit is used to realize remote command interaction and device status uploading. The digital input / output interface unit is an opto-isolated hard-wired interface used to realize emergency on / off control.

[0033] On the other hand, the digital input interface unit is designed as an opto-isolated hardwired interface independent of the digital bus. It does not rely on complex communication protocols, data encoding, or the processing of these protocols by DSP processor units. In emergency situations, such as when a forced power cut-off is required within milliseconds, or when the CAN communication network fails, the pilot or protection circuit can trigger a simple switch. This switch signal travels at the speed of light and directly affects the control link of the SiC module's isolated drive unit.

[0034] Referring to Figure 1, the control commands of the digital input interface unit and the CAN bus interface unit are logically ORed and independent of each other. By constructing a dual-redundant control architecture of CAN bus and hardwired digital input, the core control function of the solid-state circuit breaker is not affected by the failure of a single communication link or core processor, enabling the circuit breaker to simultaneously meet the contradictory requirements of aviation equipment for high informatization and extreme reliability.

[0035] The all-digital control component also includes a protection and discharge circuit unit, which is connected in parallel to the input / output terminals of the main power circuit to suppress transient overvoltages in the power circuit and complete fault energy discharge.

[0036] Specifically, this implementation adds overvoltage suppression and energy discharge protection to the system. In aviation DC power distribution systems, due to the presence of parasitic inductance in the lines, when solid-state circuit breakers perform high-speed breaking operations, especially when breaking large short-circuit currents, the rapidly changing current will induce extremely high transient overvoltages across the inductors. According to Lenz's law, the inductor will strongly resist the change in current, and the magnitude of its induced voltage is proportional to the rate of change of current. If this transient high voltage is not suppressed, it will far exceed the rated voltage of SiC power devices and other equipment on the bus, causing permanent breakdown damage.

[0037] The protection and discharge circuit unit is connected in parallel between the input and output terminals of the main power circuit. Internally, it typically integrates a snubber capacitor, a fast-clamping diode (such as a TVS diode), and a discharge circuit that can be actively turned on when necessary. During normal operation, this unit presents high impedance and does not affect the main circuit operation. When a voltage spike occurs during interruption, the snubber capacitor first acts as a buffer, absorbing the sudden voltage energy and slowing the rate of voltage rise. If the voltage continues to rise to the clamping threshold, the fast-clamping diode will instantly turn on, stabilizing the voltage at a safe level. For fault energy of a longer duration, such as lightning-induced energy or the shutdown energy of a large inductive load, the active discharge circuit will be triggered to conduct, dissipating the excess energy as heat in the discharge resistor. In this embodiment, by connecting the protection and discharge circuit unit in parallel across the main power circuit, effective suppression of interruption surge overvoltage and safe discharge of fault energy are achieved, providing double-layer protection for SiC power devices and the entire high-voltage bus system, ensuring the equipment's survivability under extreme fault conditions.

[0038] The all-digital control component also includes a voltage isolation acquisition unit and a current isolation acquisition unit; the voltage isolation acquisition unit is used to isolate and acquire the high voltage signal of the main power circuit, and the current isolation acquisition unit is used to isolate and acquire the current signal of the integrated shunt detection unit; the DSP processor unit is connected to the voltage isolation acquisition unit and the current isolation acquisition unit respectively to receive the acquired signals.

[0039] Specifically, this implementation constructs a perception layer for the system. To achieve fully digital closed-loop control and complex protection algorithms, the DSP processor unit must acquire high-precision, real-time main power circuit voltage and current information. The voltage isolation acquisition unit is responsible for sampling the high-voltage bus voltage applied across the circuit breaker. Since the bus voltage is as high as 600V or more, direct acquisition is dangerous and impractical. Therefore, this unit first converts the high voltage to a low-voltage signal proportionally through a precision resistor voltage divider network, and then transmits this low-voltage analog signal across the electrical isolation boundary to the low-voltage control side through devices such as isolation operational amplifiers or isolation ADCs, ensuring electrical isolation between the high and low voltage circuits during this process.

[0040] The current isolation acquisition unit also adopts a fully isolated analog conditioning topology. It first performs low-noise amplification and differential-to-single-ended conversion on the weak signal, and then transmits the conditioned voltage signal to the DSP processor unit via isolation devices. The high-speed analog-to-digital converter (ADC) module built into the DSP processor unit synchronously samples these isolated voltage and current signals, converting them into digital quantities. In this embodiment, by setting up fully isolated voltage and current acquisition units, the DSP processor unit can safely and accurately acquire the real-time electrical parameters of the main power circuit. This avoids the safety risks and common-mode interference problems caused by high and low voltage grounding, and provides a reliable data foundation for subsequent functions such as accurate overload protection logic, short-circuit condition detection, and energy metering.

[0041] The all-digital control assembly also includes a power supply circuit unit; the power supply circuit unit adopts a non-isolated and isolated power supply conversion topology to convert the external input voltage into non-isolated and isolated power supplies, respectively supplying power to each low-voltage side and high-voltage side unit in the all-digital control assembly.

[0042] This unit contains two independently operating power conversion paths. One is a non-isolated power conversion path, which, for example, directly converts an externally input 5V voltage to 3.3V or other logic levels via a non-isolated DC / DC converter (such as a Buck circuit). This output path is dedicated to powering the low-voltage side units in the fully digital control assembly, specifically including the DSP processor unit, the downstream digital circuitry of the CAN bus interface unit, the low-voltage outputs of the voltage isolation acquisition unit and the current isolation acquisition unit, and the I / O control logic terminals of the SiC module isolated drive unit.

[0043] The other path is an isolated power conversion. This path also draws power from an external input voltage, but transfers energy to the high-voltage side through an isolated DC / DC converter containing a high-frequency transformer. Typically, it can isolate and convert an 18V output voltage specifically for powering the high-voltage side of the SiC module's isolated drive unit, ensuring sufficient voltage and charge to drive the SiC MOSFET gate. Simultaneously, it also isolates and converts two independent 5V voltages to power the analog front-end circuits of the high-voltage side (i.e., the side directly connected to the high-voltage bus or integrated shunt detection unit) of the voltage isolation acquisition unit and the current isolation acquisition unit, respectively. In this embodiment, by employing a power conversion topology combining non-isolated and isolated power supplies, a clear, stable, and individually tailored power supply is provided from a unified external power input to the different units distributed on both sides of the isolation boundary within the entire circuit breaker, ensuring the coordinated and reliable operation of the entire system.

[0044] The circuit breaker supports bidirectional power flow and is suitable for charging and discharging of electric aircraft energy storage systems, energy feedback of propulsion systems, and flexible switching of multi-bus grid configurations.

[0045] During high-power demand phases such as takeoff or climb, the energy storage battery discharges to the propulsion motor controller through this solid-state circuit breaker, with energy flowing in the forward direction. When the aircraft enters the descent or deceleration phase, the propulsion motor becomes a generator, converting kinetic energy back into electrical energy. At this time, the current needs to flow in the reverse direction, passing through this solid-state circuit breaker to recharge the energy storage battery, achieving energy feedback. Currently, there are no mechanical circuit breakers with voltages of 270V or higher in aviation. Typically, mechanical contactors are used with current sensors or shunts for power control and protection. Mechanical contactors can achieve bidirectional current flow, but due to arcing and erosion of the mechanical contacts, their lifespan is short, reliability is low, and fault clearing response is slow. This circuit breaker seamlessly adapts to both operating conditions, has no internal mechanical contacts, has a long lifespan, high reliability, multiple protection mechanisms, and high safety. Furthermore, in multi-bus network configuration transitions, such as in a ring power supply network, to achieve fault isolation and network reconfiguration, the solid-state circuit breaker on a certain bus may need to carry power supply current or load current from different directions. This circuit breaker can function as a bidirectional channel in different configurations, making power grid dispatching more flexible. In this embodiment, by clearly defining the circuit breaker's bidirectional power flow capability, its wide applicability is highlighted in all operating conditions of aviation high-voltage power supply and distribution, such as charging and discharging of electric aircraft energy storage systems, energy feedback of propulsion systems, and flexible switching of multi-bus grid configurations.

[0046] The circuit breaker's switching process adopts a PWM linear step-type soft-connection control method, with its PWM duty cycle configurable within the range of 10% to 100%, and the PWM frequency and soft-connection time configurable.

[0047] This circuit breaker employs a fully digitally controlled PWM linear step-type soft-connection control method to solve this problem. PWM stands for Pulse Width Modulation. Upon receiving the connect command, the DSP processor unit does not immediately cause the SiC module isolation drive unit to output a continuous high level to fully turn on the SiC MOSFET chip. Instead, it issues a series of controlled PWM pulse sequences. Initially, the PWM duty cycle is set to a very small percentage, such as a lower limit of 10%. This means that in each switching cycle, the SiC MOSFET chip is only turned on for a very short time, charging a very limited amount of energy into the load capacitor. Subsequently, the DSP processor unit linearly and stepwise increases the PWM duty cycle according to a preset program, gradually increasing it from 10% to 100%. This duty cycle ramp-up process is the soft-charging process of the load capacitor. In this embodiment, by adopting PWM linear step soft-connection control with a programmable duty cycle in the range of 10% to 100%, this solid-state circuit breaker can be fully adapted to various mixed loads such as capacitive, inductive, and resistive loads that may be encountered in aircraft, thereby eliminating the current surge at the moment of connection and improving the stability of the entire power distribution system and the service life of the equipment.

[0048] The integrated aviation bidirectional solid-state circuit breaker is equipped with three independent protection mechanisms, including: I²t inverse time protection based on the DSP processor unit; microsecond-level short-circuit protection determined by hardware circuitry and controlled by the DSP processor unit; and SiC driver desaturation protection directly detected and blocked by hardware circuitry.

[0049] Firstly, I2t inverse-time protection, implemented by the DSP processor unit through real-time acquisition of current signals, adapts to the overload characteristics of aviation impulsive loads, dynamically adjusting the breaking timing based on the magnitude and duration of the overload current. Secondly, microsecond-level short-circuit protection, with hardware circuitry rapidly identifying short-circuit conditions and DSP processor software algorithms quickly capturing short-circuit transient signals and controlling the output, achieving microsecond-level arc-free breaking. Thirdly, SiC driver desaturation protection, employing a pure hardware circuit design without software intervention, directly detects the saturation state of SiC power devices. When a device exhibits desaturation anomaly, the drive signal is immediately blocked, achieving device-level rapid protection. These three protection mechanisms operate independently and collaboratively, comprehensively covering various fault scenarios. Simultaneously, the protection and discharge circuits suppress breaking surge overvoltages, achieving device and system protection. The entire unit is adapted to aviation high-voltage DC operating conditions, supporting bidirectional energy flow and flexible conversion of electric aircraft power grid configurations.

[0050] Referring to Figure 3, in another embodiment of the present invention, a control and protection method for an integrated aviation bidirectional solid-state circuit breaker based on SiC is provided, which can be used to realize the function of the integrated aviation bidirectional solid-state circuit breaker based on SiC as described in any of the above claims. Specifically, the control and protection method for the integrated aviation bidirectional solid-state circuit breaker based on SiC includes the following steps: The circuit breaker provides a SiC common-source bidirectional power module and a fully digital control component, which are electrically isolated from each other. The DSP processor unit in the fully digital control component acquires and processes the voltage and current signals of the main power circuit in real time. During normal operation, the DSP processor unit responds to CAN bus commands or hard-wired digital commands, controlling the on / off state of the SiC common-source bidirectional power module through the SiC module isolation drive unit. Simultaneously, external digital signals can control the SiC common-source bidirectional power module's connection directly through an independent control link between the digital interface unit and the SiC module isolation drive unit, without going through the DSP processor unit. Under fault conditions, the circuit breaker implements a triple independent protection mechanism: the DSP processor unit executes I²t inverse-time protection based on real-time current signals, dynamically adjusting the breaking timing; when a short circuit occurs, microsecond-level short-circuit protection is implemented, with hardware circuitry determining the short-circuit state and the DSP processor unit controlling rapid breaking; when desaturation of the SiC power device is detected, SiC... The driver desaturation protection is achieved by directly detecting and immediately blocking the drive signal through hardware circuitry, thus realizing device-level nanosecond-level protection.

[0051] The aviation high-voltage high-power intelligent solid-state circuit breaker of the present invention is composed of an integrated SiC common-source bidirectional power module and a fully digital control component. The two are connected through high-voltage power terminals and low-voltage signal terminals, and are modularly packaged to adapt to aviation airborne standard installation specifications.

[0052] The SiC common-source bidirectional power module serves as the core of power execution, employing a dual-power semiconductor device common-source symmetrical topology: the drains of the two sets of power devices serve as two external power ports of the circuit breaker, while the sources are interconnected to form a common node. A series-connected integrated shunt detection unit constitutes a complete bidirectional main power loop. In this topology, the forward and reverse current flow paths, impedances, and electrical characteristics are completely symmetrical. The shunt detection unit directly acquires the bidirectional loop current, eliminating magnetic saturation defects and significantly improving detection stability and integration.

[0053] The all-digital control component is the core of the overall machine control and detection. The implementation methods of each functional unit are as follows: The power supply circuit unit adopts a non-isolated + isolated power supply conversion topology. The non-isolated power conversion converts the externally input 5V operating voltage to 3.3V to power the DSP processor system, CAN bus interface unit, voltage / current isolation acquisition unit output, and SiC module isolation drive unit I / O control terminal in the all-digital control component. The isolated power conversion converts the externally input 5V operating voltage into one 18V and two 5V channels. The 18V power supply powers the high-voltage side of the SiC module isolation drive unit, and the two 5V channels power the high-voltage side of the voltage and current isolation acquisition units, respectively.

[0054] The DSP processor unit serves as the control center, integrating analog-to-digital conversion, PWM output, and communication peripherals to complete signal processing, algorithm calculation, instruction execution, and status management, thus constructing a fully digital closed-loop control system.

[0055] Both the voltage isolation acquisition unit and the current isolation acquisition unit adopt a fully isolated analog conditioning topology. The acquired main circuit voltage signal and shunt detection unit current signal are isolated, amplified, and conditioned before being output to the DSP processor, thus avoiding the risk of high and low voltage sharing a common ground.

[0056] The CAN bus interface unit and the digital input interface unit form a dual-redundant control architecture. The bus enables remote interaction, while the isolated hardwire enables local emergency control. The digital input control signals are not acquired and converted by the DSP processor and are directly connected to the SiC module's isolated drive unit to establish an independent control link. The DSP processor acquires the signals synchronously to obtain their status. The two links operate independently to ensure control reliability.

[0057] The SiC module isolated drive unit adopts an isolated drive topology, receives DSP control signals, and stably drives the power devices to switch on and off. At the same time, the digital interface unit establishes an independent control link with the SiC module isolated drive unit to realize direct drive of digital signals and avoid the risk of control failure caused by DSP processor failure.

[0058] The protection and discharge circuit unit is connected in parallel to the input / output terminals of the main power circuit. It integrates absorption, clamping and discharge topology to absorb and interrupt surge energy, clamp overvoltage, and achieve dual protection for power devices and bus system.

[0059] During normal operation, the DSP processor processes the acquired signals in real time and responds to dual-redundant on / off commands. Under fault conditions, a triple protection mechanism works in tandem: I2t inverse-time protection dynamically adjusts the disconnection timing based on overload conditions; short-circuit protection, achieved through a combination of hardware and software, provides microsecond-level fault isolation; and SiC driver desaturation protection provides device-level rapid protection. These triple protections are mutually redundant, comprehensively ensuring system safety. Furthermore, when the DSP processor malfunctions, external switching signals can directly act on the SiC module's isolation drive unit to control the circuit breaker connection, further enhancing its reliability.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An integrated aerospace bidirectional solid-state circuit breaker based on SiC, characterized in that, include: The SiC common-source bidirectional power module adopts a common-source symmetrical bidirectional topology structure of SiC power semiconductor device array to form a bidirectional symmetrically conducting main power control switch; the SiC common-source bidirectional power module integrates an integrated shunt detection unit, which is connected in series in the main power circuit to convert the bidirectional current signal of the main power circuit; The fully digital control component is electrically isolated from the SiC common-source bidirectional power module. The fully digital control component includes a DSP processor unit, a digital input interface unit, and a SiC module isolation drive unit. The DSP processor unit is connected to the digital input interface unit to acquire the status of digital input signals. The digital input interface unit establishes a control link with the SiC module isolation drive unit and directly controls the on / off state of the SiC common-source bidirectional power module through the SiC module isolation drive unit.

2. The SiC-based integrated bidirectional solid-state circuit breaker according to claim 1, characterized in that, The SiC common-source bidirectional power module includes two groups of SiC power semiconductor device arrays, A and B, and an integrated shunt detection unit. Group A consists of N SiC MOSFET chips connected in parallel for current amplification. The drains (D) and sources (S) of all SiC MOSFET chips are connected together. Each SiC MOSFET chip's source (S) has a separate control loop connection terminal (KS), which, together with the gate, serves as the common control terminals G_A and KS_A for the group A chip array. Group B consists of the same number of SiC MOSFET chips connected in parallel as group A, with a symmetrical chip layout. The drains (D) and sources (S) of all SiC MOSFET chips in group B are connected in the same way as in group A. The common control terminals for group B are G_B and KS_B. The sources of group A and group B are connected. The drains of group A are connected to the power supply input or output interface. The drains of group B are connected to one end of the integrated shunt detection unit, and the other end of the integrated shunt detection unit is connected to the power supply output or input interface, forming a complete bidirectional main power loop.

3. The integrated aerospace bidirectional solid-state circuit breaker based on SiC according to claim 1, characterized in that, The all-digital control component also includes a CAN bus interface unit, which, together with the digital input / output interface unit, forms a dual-redundant control architecture. The CAN bus interface unit is used to realize remote command interaction and device status uploading. The digital input / output interface unit is an opto-isolated hard-wired interface used to realize emergency on / off control.

4. The integrated aerospace bidirectional solid-state circuit breaker based on SiC according to claim 1, characterized in that, The all-digital control component also includes a protection and discharge circuit unit, which is connected in parallel to the input / output terminals of the main power circuit to suppress transient overvoltages in the power circuit and complete fault energy discharge.

5. The integrated aerospace bidirectional solid-state circuit breaker based on SiC according to claim 1, characterized in that, The all-digital control component also includes a voltage isolation acquisition unit and a current isolation acquisition unit; the voltage isolation acquisition unit is used to isolate and acquire the high voltage signal of the main power circuit, and the current isolation acquisition unit is used to isolate and acquire the current signal of the integrated shunt detection unit; the DSP processor unit is connected to the voltage isolation acquisition unit and the current isolation acquisition unit respectively to receive the acquired signals.

6. The integrated aerospace bidirectional solid-state circuit breaker based on SiC according to claim 1, characterized in that, The all-digital control assembly also includes a power supply circuit unit; the power supply circuit unit adopts a non-isolated and isolated power supply conversion topology to convert the external input voltage into non-isolated and isolated power supplies, respectively supplying power to each low-voltage side and high-voltage side unit in the all-digital control assembly.

7. The integrated aerospace bidirectional solid-state circuit breaker based on SiC according to claim 1, characterized in that, The circuit breaker supports bidirectional power flow and is suitable for charging and discharging of electric aircraft energy storage systems, energy feedback of propulsion systems, and flexible switching of multi-bus grid configurations.

8. The SiC-based integrated bidirectional solid-state circuit breaker according to claim 1, characterized in that, The circuit breaker's switching process adopts a PWM linear step-type soft-connection control method, with its PWM duty cycle configurable within the range of 10% to 100%, and its PWM frequency and soft-connection time configurable.

9. The integrated aerospace bidirectional solid-state circuit breaker based on SiC according to claim 1, characterized in that, The integrated aviation bidirectional solid-state circuit breaker is equipped with three independent protection mechanisms, including: I²t inverse time protection based on the DSP processor unit; microsecond-level short-circuit protection determined by hardware circuitry and controlled by the DSP processor unit; and SiC driver desaturation protection directly detected and blocked by hardware circuitry.

10. A control and protection method for an integrated SiC-based bidirectional solid-state circuit breaker according to any one of claims 1 to 9, characterized in that, Includes the following steps: It provides SiC common-source bidirectional power modules and fully digital control components, which are electrically isolated from each other. The DSP processor unit in the all-digital control assembly acquires and processes the voltage and current signals of the main power circuit in real time; During normal operation, the DSP processor unit responds to CAN bus commands or hard-wired digital commands and controls the on / off state of the SiC common-source bidirectional power module through the SiC module isolation drive unit. At the same time, external digital signals can control the SiC common-source bidirectional power module to be turned on directly through the independent control link between the digital interface unit and the SiC module isolation drive unit without going through the DSP processor unit. Under fault conditions, the circuit breaker implements a triple independent protection mechanism: the DSP processor unit performs I²t inverse time protection based on the real-time current signal and dynamically adjusts the breaking timing; When a short circuit occurs, microsecond-level short circuit protection is implemented. The hardware circuit determines the short circuit state and the DSP processor unit controls the rapid disconnection. When desaturation of the SiC power device is detected, SiC driver desaturation protection is implemented. The hardware circuit directly detects and immediately blocks the drive signal, achieving device-level nanosecond-level protection.

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