An external auxiliary power supply system, method and terminal device thereof

Abstract

This invention discloses an external auxiliary power supply system, method, and terminal equipment, belonging to the field of auxiliary power supply technology. The system includes: an AC / DC conversion module for receiving AC signals and outputting isolated DC signals based on the AC signals, which are then transmitted via a DC bus to a first isolation level conversion module, a second isolation level conversion module, and a timing interlock module; the first isolation level conversion module powers on the driver board based on the isolated DC signals, and the second isolation level conversion module powers on the auxiliary load based on the isolated DC signals; the timing interlock module acquires a negative turn-off bias voltage signal in real time based on the isolated DC signals, and controls a timing control switch to close when the negative turn-off bias voltage signal is determined to meet preset power supply conditions, thereby powering on the control board based on the isolated DC signals. Therefore, by implementing this invention, stable and continuous transmission of power supply signals to high-voltage power devices can be achieved.

Description

Technical Field

[0001] This invention relates to the field of auxiliary power supply technology, and in particular to an external auxiliary power supply system, method and terminal equipment thereof. Background Technology

[0002] With the advancement of new power system construction, the demand for direct-connected power electronic devices at medium-voltage levels in distribution networks continues to increase. Among these, high-voltage power semiconductor devices such as 10kV SiC MOSFETs have become core application components due to their ability to effectively improve the power density and operating efficiency of medium-voltage direct-connected power electronic devices. These high-voltage power devices typically include auxiliary loads such as driver boards, control boards, and fans. The stable operation of these devices relies on providing reliable external auxiliary power to each board and load, making the external auxiliary power supply system a crucial component. Currently, external auxiliary power supply systems for high-voltage power devices often use AC-DC conversion modules to convert AC to DC, followed by level conversion modules to supply power to different loads. This type of power supply provides basic power conversion and distribution functions for high-voltage power devices, exhibiting advantages such as a simple power supply link and high power conversion efficiency in low-voltage power device applications, making it a standard solution for auxiliary power supply of power electronic devices.

[0003] However, in high-voltage power device applications using 10kV SiC MOSFETs, existing external auxiliary power supply systems exhibit numerous compatibility issues, failing to meet the high-reliability power supply requirements of high-voltage, strong electromagnetic environments. Firstly, existing power supply systems lack differentiated power supply timing control mechanisms for the driver and control boards of high-voltage power devices, often employing synchronous power-on of both boards. In contrast, 10kV SiC... MOSFETs are extremely sensitive to gate potential. If the control board powers on and outputs control commands before the driver board, the driver board's failure to establish a reliable negative turn-off bias voltage can cause the device gate to be in a floating or high-impedance unstable state. In high-voltage scenarios, the high dv / dt (i.e., the rapid rate of change of voltage at the power device's terminals) can easily raise the gate potential through Miller capacitance, leading to serious accidents such as device false triggering and bridge arm shoot-through. Secondly, the existing power supply system's level conversion module does not have an independent isolation level conversion design for the power supply requirements of the driver board, auxiliary load, and control board. In high-voltage, strong electromagnetic environments, electromagnetic coupling interference in the power supply signal is easily generated, affecting the power supply stability of each board and load. Thirdly, the DC signal output from the existing power supply system's AC / DC conversion module lacks effective isolation design. Electrical interference from the mains side can easily be conducted to the high-voltage power device side, further reducing the reliability of the auxiliary power supply and failing to meet the high isolation and high stability requirements of the auxiliary power supply in 10kV high-voltage direct-connection scenarios. In summary, existing external auxiliary power supply systems suffer from technical problems such as unreasonable power supply timing and lack of isolation power supply design, leading to unreliable auxiliary power supply in high-voltage scenarios. Summary of the Invention

[0004] This invention provides an external auxiliary power supply system, method, and terminal equipment, which can solve the technical problems of unreliable auxiliary power supply in high-voltage scenarios caused by unreasonable power supply timing and lack of isolation power supply design in existing external auxiliary power supply systems, and realize stable and continuous transmission of power supply signals to high-voltage power devices.

[0005] This invention provides an external auxiliary power supply system applied to a high-voltage power device, the high-voltage power device including a drive board, a control board, and an auxiliary load; the system includes an AC / DC conversion module, a DC bus, a first isolation level conversion module, a second isolation level conversion module, and a timing interlock module, wherein: The AC / DC conversion module is used to receive AC signals and output isolated DC signals based on the AC signals, and output them to the DC bus. The DC bus is used to receive the isolated DC signal and transmit it to the first isolation level conversion module, the second isolation level conversion module and the timing interlocking module respectively; The first isolation level conversion module is used to perform isolation level conversion on the isolated DC signal to power on the driver board; the second isolation level conversion module is used to perform isolation level conversion on the isolated DC signal to power on the auxiliary load. A timing control switch is provided between the timing interlocking module and the control board, and the sampling terminal of the timing interlocking module is electrically connected to the negative voltage output terminal of the first isolation level conversion module. The timing interlocking module is used to acquire the negative turn-off bias voltage signal in real time based on the negative voltage output terminal, and to make a turn-off determination based on the negative turn-off bias voltage signal and a preset safety threshold. When the determination meets the preset power supply conditions, it controls the timing control switch to close, and then powers on the control board based on the isolated DC signal.

[0006] In the above solution, the external auxiliary power supply system provided by the present invention is applied to a high-voltage power device. An isolated DC signal is output to the DC bus via an AC / DC conversion module, and the DC bus supplies power to each module. The first and second isolation level conversion modules independently isolate the power supply to the drive board and auxiliary load, respectively, achieving electrical isolation between the drive board and the auxiliary load power supply and avoiding power supply interference in a high-voltage, strong electromagnetic environment. Simultaneously, a timing interlocking module obtains the isolated DC signal from the DC bus and monitors the negative turn-off bias voltage signal in real time, using a preset safety threshold to determine when to turn off. The timing control switch is closed only when the conditions are met to power on the control board. This hardware-level implementation prioritizes the power-on timing of the driver board over the control board, ensuring that the gate of the high-voltage power device has a reliable reverse turn-off bias voltage before the control board outputs control commands. This avoids false triggering caused by external interference when the gate is floating or in a high-impedance state, thus preventing device damage or system failure caused by abnormal power-on timing of the high-voltage power device from the source. At the same time, the electrical connection design between each module and the DC bus ensures the stability and continuity of power supply signal transmission, and can adapt to the auxiliary power supply requirements of the high-voltage power device.

[0007] Furthermore, the AC / DC conversion module includes a power frequency isolation submodule and an AC / DC conversion submodule, wherein: The power frequency isolation submodule is used to receive the AC signal and output an isolated AC signal to the AC-DC conversion submodule; The AC / DC conversion submodule is used to convert the isolated AC signal to an isolated DC signal and transmit it to the DC bus.

[0008] In the above scheme, the AC / DC conversion module is divided into a power frequency isolation submodule and an AC / DC conversion submodule. The power frequency isolation submodule first isolates the received AC signal and outputs an isolated AC signal, realizing primary electrical isolation between the mains side and the high-voltage power device side, effectively blocking the transmission of electrical interference from the mains side to the high-voltage power device side. The AC / DC conversion submodule then converts the isolated AC signal into an isolated DC signal. Through the hierarchical processing of power frequency isolation and AC / DC conversion, the purity and stability of the output isolated DC signal are improved, avoiding electromagnetic coupling interference caused by direct AC / DC conversion, further ensuring the reliability of DC bus power supply, and laying the foundation for the stable operation of subsequent isolation level conversion modules and timing interlocking modules. At the same time, the hierarchical module design also makes the isolation protection of the power supply system more layered and adaptable to the insulation requirements of high-voltage scenarios.

[0009] Furthermore, the power frequency isolation submodule includes an iron core, a primary side, a secondary side, an inner shielding layer, and an outer shielding layer, wherein: The primary side includes a first primary winding and a second primary winding connected in series, and the secondary side includes a secondary winding. The first primary winding, the second primary winding, and the secondary winding are respectively wound on the iron core. The original side is used to receive the AC signal; The secondary side is used to electrically connect to the AC / DC conversion submodule, and the secondary side is used to transmit the isolated AC output signal generated based on the AC signal to the AC / DC conversion submodule; There is electrical insulation between the inner shielding layer and the outer shielding layer; The inner shielding layer is tightly attached to the surface of the primary side and is electrically connected to the protective ground. The inner shielding layer is used to discharge the primary side common-mode current generated on the primary side to the protective ground. The outer shielding layer is tightly attached to the secondary side surface and is electrically connected to the power ground of the high-voltage power device. The outer shielding layer is used to discharge the secondary common-mode current generated on the secondary side to the power ground.

[0010] In the above scheme, the system sets the power frequency isolation submodule as an iron core, including the primary side of the first and second primary windings connected in series, the secondary side of the secondary winding, and an inner and outer shielding layer. The first, second, and secondary primary windings are wound on the iron core. Utilizing the electromagnetic coupling effect of the iron core, stable transmission of AC signals from the primary side to the secondary side is achieved. Simultaneously, the series-connected double primary winding design optimizes the winding potential distribution on the iron core, avoiding the potential unevenness problem that exists with a single winding in high-voltage scenarios. The electrical insulation design between the inner and outer shielding layers ensures proper connection between the primary and secondary sides. The system provides electrical isolation; simultaneously, the inner shielding layer is tightly fitted to the primary side and connected to the protective ground, which can quickly discharge the primary common-mode current generated on the primary side to the protective ground. The outer shielding layer is tightly fitted to the secondary side and connected to the power ground of the high-voltage power device, which can promptly discharge the secondary common-mode current generated on the secondary side to the power ground. This achieves an independent common-mode current discharge design with dual shielding layers, which significantly reduces the electromagnetic coupling between the primary and secondary sides, effectively suppresses signal interference caused by common-mode current in high-voltage scenarios, and avoids common-mode current breakdown of winding insulation. This improves the insulation performance and anti-interference capability of the power frequency isolation submodule, and ensures stable output of isolated AC signals.

[0011] Furthermore, the primary side of the power frequency isolation submodule also includes a first voltage divider resistor and a second voltage divider resistor; wherein: the first voltage divider resistor is connected in parallel across the two ends of the first primary winding, and the second voltage divider resistor is connected in parallel across the two ends of the second primary winding.

[0012] In the above scheme, the system adds first and second voltage-dividing resistors, respectively, in parallel across the first and second primary windings, to the primary side of the power frequency isolation submodule. These resistors divide and adjust the voltage of the corresponding primary windings, further optimizing the potential distribution on the primary side. This makes the potential of the first and second primary windings more uniform, preventing partial discharge or insulation breakdown in a single winding due to excessively high potential. Simultaneously, by setting the impedance of the voltage-dividing resistors to be much lower than the capacitive reactance formed by the parasitic capacitance of the windings, the potential shift caused by parasitic capacitance is effectively suppressed, improving the stability of the primary side operation. This, in turn, ensures the stability of the electromagnetic coupling of the power frequency isolation submodule, making the output isolated AC signal more stable and adaptable to the power frequency isolation requirements in high-voltage scenarios.

[0013] Furthermore, an air gap is provided between the inner shielding layer and the outer shielding layer, and the air gap is used to maintain electrical insulation between the inner shielding layer and the outer shielding layer.

[0014] In the above scheme, the electrical insulation between the inner and outer shielding layers is designed as an air gap. As a natural insulating medium, the air gap can stably maintain the electrical insulation performance between the inner and outer shielding layers, preventing electrical conduction between the shielding layers. At the same time, the design of the air gap will not introduce additional parasitic capacitance, and will not interfere with the electromagnetic coupling and common-mode current discharge of the primary and secondary sides. Compared with other insulating materials, the insulation performance of the air gap is more stable and more adaptable to the strong electromagnetic environment of high-voltage power devices, ensuring that the inner and outer shielding layers can independently achieve the function of common-mode current discharge, and further improving the insulation and anti-coupling capability of the power frequency isolation submodule.

[0015] Further: The AC / DC conversion submodule includes a full-bridge rectifier unit, a first supporting capacitor, a high-frequency inverter unit, a filter unit, a high-frequency transformer unit, a high-frequency rectifier unit, and a second supporting capacitor, wherein: The receiving end of the full-bridge rectifier unit is used to receive the isolated AC signal; The first output terminal of the full-bridge rectifier unit is electrically connected to the first terminal of the first supporting capacitor, the second output terminal of the full-bridge rectifier unit is electrically connected to the second terminal of the first supporting capacitor, the first output terminal of the full-bridge rectifier unit is electrically connected to the first receiving terminal of the high-frequency inverter unit, and the second output terminal of the full-bridge rectifier unit is electrically connected to the second receiving terminal of the high-frequency inverter unit. The first output terminal of the high-frequency inverter unit is electrically connected to the first terminal of the filter unit, and the second output terminal of the high-frequency inverter unit is electrically connected to the second terminal of the filter unit. The second end of the filtering unit is electrically connected to the first receiving end of the high-frequency transformer unit, and the third end of the filtering unit is electrically connected to the second receiving end of the high-frequency transformer unit. The first output terminal of the high-frequency transformer unit is electrically connected to the first receiving terminal of the high-frequency rectifier unit, and the second output terminal of the high-frequency transformer unit is electrically connected to the second receiving terminal of the high-frequency rectifier unit. The first output terminal of the high-frequency rectifier unit is electrically connected to the first terminal of the second supporting capacitor, and the second output terminal of the high-frequency rectifier unit is electrically connected to the second terminal of the second supporting capacitor. The first output terminal and the second output terminal of the high-frequency rectifier unit are respectively electrically connected to the DC bus. The first output terminal and the second output terminal of the high-frequency rectifier unit are used to transmit the obtained isolated DC signal to the DC bus.

[0016] In the above scheme, the AC / DC conversion submodule of the system first rectifies the isolated AC signal through a full-bridge rectifier unit, and then uses a first supporting capacitor to filter and smooth the rectified signal to improve the stability of the DC signal. Next, the smoothed DC signal is inverted into a high-frequency AC signal through a high-frequency inverter unit to improve the efficiency of subsequent power conversion. The high-frequency AC signal is filtered by a filtering unit to remove harmonic interference and ensure the purity of the high-frequency AC signal. The filtered high-frequency AC signal is isolated and transformed by a high-frequency transformer unit to achieve secondary electrical isolation and further improve insulation performance. The isolated high-frequency AC signal is rectified into a DC signal by a high-frequency rectifier unit and filtered and smoothed again by a second supporting capacitor, finally outputting a stable isolated DC signal to the DC bus. The entire AC / DC conversion submodule achieves the conversion from isolated AC signals to stable isolated DC signals through graded processing of rectification, filtering, inversion, filtering, transformation, rectification, and filtering. The multi-stage filtering and isolation design significantly reduces harmonics and interference in the signal, improves the accuracy and stability of the output isolated DC signal, and the high-frequency conversion design improves the power conversion efficiency and reduces the module size, making it suitable for the small size and high reliability requirements of auxiliary power supply for high-voltage power devices.

[0017] Further: the filtering unit includes a filter inductor and a filter capacitor, wherein: The first end of the filter inductor serves as the first end of the filter unit, the second end of the filter inductor is electrically connected to the first end of the filter capacitor, the second end of the filter capacitor serves as the second end of the filter unit, and the second end of the filter inductor serves as the third end of the filter unit.

[0018] In the above scheme, the filtering unit is designed as a combination of a filtering inductor and a filtering capacitor, and corresponding circuit connections are made. The filtering inductor can effectively suppress series harmonic interference in high-frequency AC signals, and the filtering capacitor can quickly filter out parallel harmonic components in high-frequency AC signals. The combination of the two forms an LC filtering circuit, which can specifically filter out harmonics and noise in the output signal of the high-frequency inverter unit, improve the sinusoidal quality and purity of the high-frequency AC signal, provide a high-quality input signal for the stable operation of the subsequent high-frequency transformer unit, avoid electromagnetic coupling abnormalities caused by harmonic interference, and thus ensure the stability of the final output isolated DC signal of the AC-DC conversion submodule.

[0019] Furthermore, the timing interlocking module is also used to control the timing control switch to remain in the off state when it is determined that the preset power supply conditions are not met, so that the control board remains in the unpowered state, and to make a shutdown determination in real time until the preset power supply conditions are met.

[0020] In the above scheme, the system designs a timing interlocking module to determine the action logic when the preset power supply conditions are not met. At this time, the timing interlocking module controls the timing control switch to remain in the open state, keeping the control board in an unpowered state, and continuously performs shutdown determination in real time until the conditions are met. This achieves hardware-level interlocking protection for the power supply to the control board. As long as the negative shutdown bias voltage does not reach the preset safety threshold, the control board will never be powered on. This avoids false triggering caused by the control board outputting commands when there is no reliable reverse shutdown voltage at the gate of the power device due to abnormal situations such as voltage failure, insufficient voltage, or voltage fluctuation. At the same time, the real-time determination design can close the switch in time to power on the control board when the negative shutdown bias voltage recovers to a safe state, without manual intervention. This achieves automatic and reliable control of the power supply timing, further improving the working safety and fault tolerance of the entire external auxiliary power supply system in high-voltage scenarios.

[0021] This invention provides an external auxiliary power supply method applied to a high-voltage power device including a driver board, a control board, and an auxiliary load, for implementing an external auxiliary power supply system. The system includes an AC / DC conversion module, a DC bus, a first isolation level conversion module, a second isolation level conversion module, and a timing interlock module. A timing control switch is provided between the timing interlock module and the control board. The sampling terminal of the timing interlock module is electrically connected to the negative voltage output terminal of the first isolation level conversion module. Using the timing interlock module as the execution entity, the method includes: When the AC / DC conversion module receives an AC signal and outputs an isolated DC signal to the DC bus based on the AC signal, the first isolation level conversion module performs isolation level conversion on the isolated DC signal to power on the driver board, and the second isolation level conversion module performs isolation level conversion on the isolated DC signal to power on the auxiliary load. Receive isolated DC signals from the DC bus; The negative turn-off bias voltage signal is acquired in real time based on the negative voltage output terminal; The shutdown determination is made based on the negative shutdown bias voltage signal and the preset safety threshold. When the preset power supply conditions are met, the timing control switch is closed, and the control board is powered on based on the isolated DC signal.

[0022] The external auxiliary power supply method provided by this invention is based on an external auxiliary power supply system. It uses a timing interlocking module as the execution entity. After the AC / DC conversion module outputs an isolated DC signal, and the first and second isolated level conversion modules power on the driver board and auxiliary load respectively, the timing interlocking module receives the isolated DC signal from the DC bus, acquires and determines the negative turn-off bias voltage signal in real time, and powers on the control board only when the conditions are met. This method strictly follows the timing logic of prioritizing driver board power-on. It achieves precise control of the power-on sequence through the actions of corresponding hardware modules, avoiding uncertainties such as delays and crashes inherent in software control. This ensures that the gate of the high-voltage power device always receives a reliable reverse turn-off voltage before receiving control commands from the control board. From a methodological perspective, this guarantees the safety of auxiliary power supply in high-voltage scenarios. Furthermore, the execution process of the method is highly compatible with the system hardware, and the connection between each step relies on the electrical connection and signal transmission of the hardware modules, ensuring the stability and operability of the power supply method.

[0023] The present invention also provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements an external auxiliary power supply method as described above.

[0024] Another embodiment of the present invention provides a computer-readable storage medium item, including: a stored computer program, which, when the computer program is running, controls the device where the computer-readable storage medium is located to perform steps such as the external auxiliary power supply method of the present invention.

[0025] The implementation of this invention has the following beneficial effects: The entire external auxiliary power supply system and corresponding power supply method provided by this invention, through the overall design of hierarchical isolation, independent level conversion, and hardware-level timing interlock control, achieve high insulation, low electromagnetic coupling, and high timing safety in the auxiliary power supply of high-voltage power devices; the multi-level isolation design of power frequency isolation and high-frequency transformer significantly improves the insulation performance of the system, effectively blocking electrical interference between the mains side and the high-voltage power device side; the design of double shielding layer combined with voltage divider resistor optimizes the potential distribution, efficiently discharges common-mode current, further reduces electromagnetic coupling, and avoids local... The system eliminates the possibility of partial discharge or insulation breakdown. Multi-stage filtering and rectification design ensures the stability and purity of the isolated DC signal, providing reliable power to the driver board, control board, and auxiliary loads. Hardware-based timing interlocking control enables precise power-on of the driver board prior to the control board, completely eliminating the uncertainty of software control and ensuring that the gates of power devices are always reliably off before receiving control commands. This avoids high-voltage safety accidents such as bridge arm shoot-through and device damage caused by gate mis-triggers. Simultaneously, the hierarchical design and independent power supply of each module make the system's power management more targeted, adapting to the high-voltage, strong electromagnetic environment and low-power auxiliary power supply requirements of high-voltage power devices such as 10kV SiC MOSFET power units. This significantly improves the overall reliability and safety of auxiliary power supply for high-voltage power devices, effectively solving the problems of insufficient insulation, severe coupling, and unreliable timing control in existing auxiliary power supply solutions under high-voltage scenarios. Attached Figure Description

[0026] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of an external auxiliary power supply system provided in this embodiment; Figure 2 This is a schematic diagram of the high isolation transformer provided in this embodiment; Figure 3 This is a schematic diagram of a highly reliable external centralized auxiliary power supply architecture for a 10kV SiC MOSFET power unit provided in this embodiment. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0030] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0031] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0032] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0033] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0034] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0035] Example 1: This embodiment provides an external auxiliary power supply system, such as Figure 1 As shown, this is applied to a high-voltage power device, which includes a drive board, a control board, and an auxiliary load; the system includes an AC / DC conversion module, a DC bus, a first isolation level conversion module, a second isolation level conversion module, and a timing interlock module, wherein: The AC / DC conversion module is used to receive AC signals and output isolated DC signals based on the AC signals, and output them to the DC bus. The DC bus is used to receive the isolated DC signal and transmit it to the first isolation level conversion module, the second isolation level conversion module and the timing interlocking module respectively; The first isolation level conversion module is used to perform isolation level conversion on the isolated DC signal to power on the driver board; the second isolation level conversion module is used to perform isolation level conversion on the isolated DC signal to power on the auxiliary load. A timing control switch S is provided between the timing interlocking module and the control board, and the sampling terminal of the timing interlocking module is electrically connected to the negative voltage output terminal of the first isolation level conversion module. The timing interlocking module is used to acquire the negative turn-off bias voltage signal in real time based on the negative voltage output terminal, and to make a turn-off determination based on the negative turn-off bias voltage signal and a preset safety threshold. When the determination meets the preset power supply conditions, it controls the timing control switch S to close, and then powers on the control board based on the isolated DC signal.

[0036] In the above scheme, the external auxiliary power supply system provided in this embodiment is applied to a high-voltage power device. An isolated DC signal is output to the DC bus via an AC-DC conversion module, and the DC bus supplies power to each module. The first and second isolation level conversion modules independently isolate the power supply to the drive board and auxiliary load, respectively, achieving electrical isolation between the drive board and the auxiliary load power supply and avoiding power supply interference in a high-voltage, strong electromagnetic environment. Simultaneously, a timing interlocking module obtains the isolated DC signal from the DC bus and monitors the negative turn-off bias voltage signal in real time, using a preset safety threshold for turn-off judgment. The timing control switch is closed only when the conditions are met to power on the control board. This hardware-level implementation prioritizes the power-on timing of the driver board over the control board, ensuring that the gate of the high-voltage power device has a reliable reverse turn-off bias voltage before the control board outputs control commands. This avoids false triggering caused by external interference when the gate is floating or in a high-impedance state, thus preventing device damage or system failure caused by abnormal power-on timing of the high-voltage power device from the source. At the same time, the electrical connection design between each module and the DC bus ensures the stability and continuity of power supply signal transmission, and can adapt to the auxiliary power supply requirements of the high-voltage power device.

[0037] in, Figure 1 In this context, +DC represents the positive terminal of the DC bus. Figure 1 -DC in the diagram represents the negative terminal of the DC bus. The AC / DC conversion module receives AC signals from a single-phase 220V mains power supply. The DC bus is powered by the isolated DC signal output from the AC / DC conversion module, which supplies power to the first isolation level conversion module, the second isolation level conversion module, and the timing interlocking module, thereby enabling power supply to the drive board, control board, and auxiliary load of the high-voltage power device.

[0038] In practical implementation, with the construction and development of new power systems, the demand for direct-connection applications of power electronic devices at medium-voltage levels in distribution networks is increasing. The application of high-voltage power semiconductor devices (i.e., high-voltage power devices, such as 10kV SiC MOSFETs) at voltage levels of 6.5kV and above in medium-voltage direct-connected power electronic devices can effectively improve the power density and operating efficiency of the devices. Therefore, such high-voltage power semiconductor devices have good application prospects in the field of medium-voltage direct-connected power electronic devices. However, with the increase in the grid-side voltage level and the DC bus voltage level inside the power electronic device, achieving highly reliable auxiliary power supply for power units based on 10kV SiC MOSFETs has become a pressing technical problem to be solved in this field. The auxiliary loads inside this power unit, such as the drive board, control board, and fans, all need to operate reliably in a high-voltage, strong electromagnetic environment. The power supply guarantee for the drive board and control board is particularly critical to the stable operation of the power unit.

[0039] However, there are currently no mature commercial driver boards for 10kV SiC MOSFETs. Due to size design limitations, most self-developed driver boards do not have high-voltage isolation functions. In practical applications, the power supply circuit of the self-developed driver board is directly connected to the high-voltage power circuit, which poses a potential power supply safety hazard. At the same time, in order to ensure the reliable operation of the power unit, a reasonable power-on sequence needs to be designed for the driver board, control board and auxiliary load to avoid faults such as false triggering of power devices caused by improper power-on sequence. In current technologies, there are two main types of auxiliary power supply solutions for power units: one is a self-powered auxiliary power supply architecture, which draws power directly from the DC bus of the power unit to provide auxiliary power to each module of the power unit. Its advantage lies in the simplicity of the power supply circuit. The other is an external centralized auxiliary power supply architecture, which supplies power to each module of the power unit through an independent low-voltage power supply, after isolation and level conversion by a high-isolation power frequency transformer. In application scenarios with a small number of power units, it can simplify the power supply wiring structure and achieve centralized management, unified voltage regulation and output isolation of auxiliary power supply. It can also reduce the power loss and energy coupling problems that are prone to occur in the self-powered auxiliary power supply architecture. However, in application scenarios with high-voltage DC buses, the self-powered auxiliary power supply architecture has low power supply reliability and is difficult to adapt to the high-voltage application requirements of 10kV SiC MOSFET power units.

[0040] In summary, there is currently no external centralized auxiliary power supply architecture designed for power units based on 10kV SiC MOSFETs. Existing self-powered auxiliary power supply solutions are mostly applicable to power units with DC bus voltage levels below 2000V, while power units based on 10kV SiC MOSFETs typically have DC bus voltage levels above 4.5kV, making existing self-powered auxiliary power supply solutions unsuitable for the auxiliary power supply requirements of such high-voltage power units. For external centralized auxiliary power supply architectures, existing designs are all geared towards power electronic devices with lower grid-side voltage levels. When directly applied to 10kV SiC MOSFET power units, the isolation transformer in the auxiliary power supply system is prone to partial discharge or even insulation breakdown due to uneven winding potential distribution. Furthermore, the 10kV SiC MOSFET generates a dv / dt as high as 250kV / µs during switching. This high-voltage change rate generates a large displacement current through the mutual capacitance coupling between the primary and secondary sides of the isolation transformer. This displacement current penetrates the transformer insulation layer and flows to the low-voltage control side, causing interference or even damage to the low-voltage control circuit. Simultaneously, existing auxiliary power supply architectures cannot achieve precise control of the power-on sequence of each module within the 10kV SiC MOSFET power unit. Some solutions use software to achieve timing control, but such software control solutions suffer from large control delays, making it difficult to meet the high reliability requirements of high-voltage power units for power-on sequence.

[0041] Therefore, to solve the above-mentioned technical problems, this embodiment proposes a method as follows: Figure 1 The external auxiliary power supply system shown is designed to meet the requirements of prioritizing power supply to the drive board and then powering the auxiliary load in a 10kV SiC MOSFET power unit, and to avoid device erroneous triggering caused by abnormal drive signals. The system adds a timing interlock module and a timing control switch S between the DC bus and the control board. The timing interlock module is used to control the timing of the power supply to the control board by turning off the timing control switch S designed on it.

[0042] Specifically, this embodiment addresses the extreme sensitivity of 10kV SiC MOSFETs to gate potential. At the end of the auxiliary power supply, a hardware-interlocked active protection logic is established using a timing interlock module and a timing control switch. During system startup or voltage establishment transients, if the driver board power supply (typically +20V / -5V) lags behind the logic establishment of the main control circuit (i.e., the control board), the gate of the 10kV SiC MOSFET may be in a floating or unstable high-impedance state. In this case, the residual dv / dt on the control board may raise the gate potential through the Miller capacitance Cgd, potentially causing a bridge arm shoot-through accident under high voltage. Therefore, this embodiment introduces a timing interlock circuit before the control board. The timing interlock module in this circuit uses a high-precision hardware voltage comparator to monitor the negative turn-off bias voltage of the driver power supply in real time and makes a turn-off determination based on the negative turn-off bias voltage signal and a preset safety threshold. Only when the negative turn-off bias voltage is established and reaches a preset safety threshold (e.g., below -4.5V) is the preset power supply condition determined, and the output of the hardware voltage comparator generates an enable signal EN. This enable signal EN controls the timing control switch S to close, thereby powering on the control board based on an isolated DC signal. This ensures that at the moment of power-on, the gate of the 10kV SiC MOSFET has obtained a reliable reverse turn-off voltage before the system receives external PWM control commands. This system can provide centralized auxiliary power supply to high-voltage power devices (such as 10kV silicon carbide (SiC) power units), and through reasonable power-on timing design, it achieves a protection control logic that prioritizes drive during auxiliary power supply power-on, filling the gap in current designs of centralized auxiliary power supply systems based on 10kV SiC MOSFETs.

[0043] Optionally, the AC / DC conversion module includes a power frequency isolation submodule and an AC / DC conversion submodule, wherein: The power frequency isolation submodule is used to receive the AC signal and output an isolated AC signal to the AC-DC conversion submodule; The AC / DC conversion submodule is used to convert the isolated AC signal to an isolated DC signal and transmit it to the DC bus.

[0044] Optionally, the power frequency isolation submodule includes an iron core, a primary side, a secondary side, an inner shielding layer, and an outer shielding layer, wherein: The primary side includes a first primary winding and a second primary winding connected in series, and the secondary side includes a secondary winding. The first primary winding, the second primary winding, and the secondary winding are respectively wound on the iron core. The original side is used to receive the AC signal; The secondary side is used to electrically connect to the AC / DC conversion submodule, and the secondary side is used to transmit the isolated AC output signal generated based on the AC signal to the AC / DC conversion submodule; There is electrical insulation between the inner shielding layer and the outer shielding layer; The inner shielding layer is tightly attached to the surface of the primary side and is electrically connected to the protective ground. The inner shielding layer is used to discharge the primary side common-mode current generated on the primary side to the protective ground. The outer shielding layer is tightly attached to the secondary side surface and is electrically connected to the power ground of the high-voltage power device. The outer shielding layer is used to discharge the secondary common-mode current generated on the secondary side to the power ground.

[0045] In the specific implementation process, the primary common-mode current generated on the primary side specifically refers to the common-mode current generated by parasitic capacitance coupling on the primary side, and the secondary common-mode current generated on the secondary side specifically refers to the common-mode current generated by parasitic capacitance coupling on the secondary side.

[0046] Optionally, the primary side of the power frequency isolation submodule further includes a first voltage divider resistor and a second voltage divider resistor; wherein: the first voltage divider resistor is connected in parallel across the two ends of the first primary winding, and the second voltage divider resistor is connected in parallel across the two ends of the second primary winding.

[0047] Optionally, an air gap is provided between the inner shielding layer and the outer shielding layer, the air gap being used to maintain electrical insulation between the inner shielding layer and the outer shielding layer.

[0048] In practical implementation, the power frequency isolation submodule described above in this embodiment implements a high isolation transformer design, applicable to 10kV SiC MOSFET power units. This high isolation transformer, as described above... Figure 2As shown, to address the problem of uneven potential distribution in traditional windings under high insulation voltage, this embodiment provides a high-isolation transformer comprising a first primary winding S1 and a second primary winding S2. The primary winding is physically divided into two independent segments, S1 and S2. A first voltage-dividing resistor R1 and a second voltage-dividing resistor R2 are introduced, connecting the two resistors to the midpoints of the two primary windings to establish a defined resistive voltage-dividing branch with an impedance significantly lower than the capacitive reactance formed by parasitic capacitance. In this embodiment, the rated power of the high-isolation transformer is designed to be less than 100W. Furthermore, to reduce coupling between the primary and secondary windings, this embodiment constructs a composite physical barrier between the primary and secondary windings of the high-isolation transformer, consisting of a double-layer aluminum foil electrostatic shield combined with an air gap. The double-layer aluminum foil electrostatic shielding is achieved by an inner shielding layer 1 and an outer shielding layer 2. The inner shielding layer 1 is adjacent to the primary winding and directly connected to the system ground GND (i.e., the protective ground). The outer shielding layer 2 is adjacent to the secondary winding S3 and connected to the power ground G of the power unit. The inner and outer shielding layers do not contact each other, and an air gap 3 is reserved in between to maintain electrical insulation. At this time, it is ensured that the high-frequency common-mode current generated on the secondary side flows directly back to the power ground on the high-voltage side through the outer shielding layer 2, and does not cross the air gap to enter the ground loop on the primary side.

[0049] This embodiment designs a power frequency isolation submodule suitable for high-voltage, low-power scenarios. It uses an iron core as the magnetic coupling basis, dividing the primary winding into two series windings with parallel voltage divider resistors to optimize the potential distribution on the primary side. A tightly fitted inner shielding layer 1 and outer shielding layer 2 are respectively placed on the primary and secondary sides, with an air gap between the shielding layers for electrical insulation. The inner shielding layer 1 is connected to protective ground, and the outer shielding layer 2 is connected to power ground, effectively discharging common-mode current on the primary and secondary sides. This structural design can simultaneously achieve high insulation performance and low electromagnetic coupling performance in the high dv / dt and complex electric field environment generated by 10kV SiC MOSFETs, avoiding displacement current interference and insulation faults. Under the premise of carrying the grid-side voltage insulation level, this module structure further optimizes the winding potential distribution through structured intervention of the internal electromagnetic field distribution, achieving a balance between high insulation and low electromagnetic coupling. The independent common-mode current discharge design of the inner shielding layer 1 and outer shielding layer 2 effectively suppresses the 10kV SiC... The displacement current interference caused by the high dv / dt generated by the MOSFET avoids problems such as insulation breakdown and partial discharge.

[0050] In the specific implementation process, the external auxiliary power supply system of this embodiment, through the reasonable design of the high isolation transformer and power-on timing, not only realizes the protection control logic of driving priority at the moment of auxiliary power supply power-on, but also achieves the balance between high insulation and low coupling of the isolation transformer.

[0051] Optional: The AC / DC conversion submodule includes a full-bridge rectifier unit, a first supporting capacitor, a high-frequency inverter unit, a filter unit, a high-frequency transformer unit, a high-frequency rectifier unit, and a second supporting capacitor, wherein: The receiving end of the full-bridge rectifier unit is used to receive the isolated AC signal; The first output terminal of the full-bridge rectifier unit is electrically connected to the first terminal of the first supporting capacitor, the second output terminal of the full-bridge rectifier unit is electrically connected to the second terminal of the first supporting capacitor, the first output terminal of the full-bridge rectifier unit is electrically connected to the first receiving terminal of the high-frequency inverter unit, and the second output terminal of the full-bridge rectifier unit is electrically connected to the second receiving terminal of the high-frequency inverter unit. The first output terminal of the high-frequency inverter unit is electrically connected to the first terminal of the filter unit, and the second output terminal of the high-frequency inverter unit is electrically connected to the second terminal of the filter unit. The second end of the filtering unit is electrically connected to the first receiving end of the high-frequency transformer unit, and the third end of the filtering unit is electrically connected to the second receiving end of the high-frequency transformer unit. The first output terminal of the high-frequency transformer unit is electrically connected to the first receiving terminal of the high-frequency rectifier unit, and the second output terminal of the high-frequency transformer unit is electrically connected to the second receiving terminal of the high-frequency rectifier unit. The first output terminal of the high-frequency rectifier unit is electrically connected to the first terminal of the second supporting capacitor, and the second output terminal of the high-frequency rectifier unit is electrically connected to the second terminal of the second supporting capacitor. The first output terminal and the second output terminal of the high-frequency rectifier unit are respectively electrically connected to the DC bus. The first output terminal and the second output terminal of the high-frequency rectifier unit are used to transmit the obtained isolated DC signal to the DC bus.

[0052] Optionally: The filtering unit includes a filter inductor and a filter capacitor, wherein: The first end of the filter inductor serves as the first end of the filter unit, the second end of the filter inductor is electrically connected to the first end of the filter capacitor, the second end of the filter capacitor serves as the second end of the filter unit, and the second end of the filter inductor serves as the third end of the filter unit.

[0053] Optionally, the timing interlocking module is further configured to control the timing control switch S to remain in the open state when it is determined that the preset power supply conditions are not met, so that the control board remains in the unpowered state, and to make a shutdown determination in real time until the preset power supply conditions are met.

[0054] In practical implementation, this embodiment provides a highly reliable external centralized auxiliary power supply architecture suitable for 10kV SiC MOSFET power units, such as... Figure 3As shown, an external auxiliary power supply system is used. The core design goal of this auxiliary power supply architecture is to adapt to the low-power auxiliary power supply requirements of less than 100W in a 10kV high-voltage direct-connection scenario. It is customized to meet the high isolation requirements, small size constraints, and high reliability requirements of power supply timing in this specific scenario. The system includes: a power frequency isolation submodule, a full-bridge rectifier unit, a first supporting capacitor C1, a high-frequency inverter unit, a filter inductor L1, a filter capacitor C2, a high-frequency transformer unit, a high-frequency rectifier unit, a second supporting capacitor C3, a DC bus, a first isolation level conversion module, a second isolation level conversion module, a timing interlock module, and a timing control switch S. The primary side of the power frequency isolation submodule receives AC signals from a single-phase 220V mains power supply. This auxiliary power supply architecture is applied to a 10kV SiCMOSFET high-voltage power device, which includes a driver board, a control board, and an auxiliary load.

[0055] Specifically, the power frequency isolation submodule used in this embodiment is a low-power power frequency high isolation transformer structure. Its primary side is used to receive AC signals from a single-phase 220V mains power supply. The specific circuit connection relationship is as follows: The primary side of the power frequency isolation submodule is electrically connected to the single-phase 220V mains power interface to obtain the power frequency AC signal; the secondary side of the power frequency isolation submodule is electrically connected to the AC input terminal (i.e., the receiving terminal) of the full-bridge rectifier unit. In this embodiment, the full-bridge rectifier unit uses SiC Schottky diodes to convert the isolated AC signal output by the power frequency isolation submodule into a DC signal; the DC output terminal of the full-bridge rectifier unit (including the first output terminal and the second output terminal) is electrically connected to the first supporting capacitor C1. In this embodiment, the first supporting capacitor C1 is a low-ESR ceramic multilayer high-frequency supporting capacitor to filter and smooth the DC signal output by the full-bridge rectifier unit to adapt to the high switching frequency operation requirements of the subsequent high-frequency inverter stage. The output terminal of the first supporting capacitor C1 (i.e., the first and second terminals of the first supporting capacitor) is electrically connected to the DC side of the high-frequency inverter unit through the first and second receiving terminals of the high-frequency inverter unit. In this embodiment, the high-frequency inverter unit adopts a GaN single-phase full-bridge high-frequency inverter structure, and its switching frequency is increased to 1MHz to convert the smoothed DC signal into a high-frequency AC signal. The AC side of the high-frequency inverter unit is electrically connected to the filter circuit composed of filter inductor L1 and filter capacitor C2 in sequence through the first and second output terminals of the high-frequency inverter unit. In this embodiment, the filter inductor L1 is an inductor made by microstrip winding technology, and the filter capacitor C2 is a high-frequency capacitor made of NPO material. The two work together to filter the high-frequency AC signal output by the high-frequency inverter unit, filter out harmonic interference, and improve signal purity. The output terminal of the filter capacitor C2 (i.e., the second terminal of the filter unit) and the third terminal of the filter unit are electrically connected to the primary side of the high-frequency transformer unit through the first and second receiving terminals of the high-frequency transformer unit, respectively. In this embodiment, the high-frequency transformer unit adopts a high-frequency miniature transformer with a planar magnetic core structure, which is used to isolate and transform the filtered high-frequency AC signal again. The secondary side of the high-frequency transformer unit is electrically connected to the AC input terminal (including the first and second receiving terminals of the high-frequency rectifier unit) of the high-frequency rectifier unit through the first and second output terminals of the high-frequency transformer unit. In this embodiment, the high-frequency rectifier unit adopts a GaN HEMT structure, which is used to rectify the isolated high-frequency AC signal output by the high-frequency transformer unit into a DC signal again. The DC output terminal (including the first and second output terminals of the high-frequency rectifier unit) of the high-frequency rectifier unit is electrically connected to the second supporting capacitor C3. After being filtered and smoothed by the second supporting capacitor C3, a stable DC bus is formed at its output terminal to provide power supply for subsequent modules.The DC bus is electrically connected to the first isolation level conversion module, the second isolation level conversion module, and the timing interlock module, respectively. The first isolation level conversion module is used to perform isolation level conversion on the DC voltage (i.e., isolated DC signal) output from the DC bus, converting it into a dedicated drive power supply voltage suitable for the driver board, thereby powering the driver board. The second isolation level conversion module is used to perform isolation level conversion on the DC voltage output from the DC bus, converting it into a voltage suitable for the auxiliary load, thereby powering the auxiliary load. The timing interlock module is equipped with a timing control switch S. The timing interlock module is used to obtain power from the DC bus and collect the negative turn-off bias voltage signal output by the first isolation level conversion module in real time. After completing the turn-off determination based on this signal, the timing control switch S is used to realize the power supply timing control of the control board. The device selection and circuit connection design of the above modules are adapted to the high-voltage and strong electromagnetic working environment of 10kV SiC MOSFET high-voltage power devices. They also take into account the high insulation, low electromagnetic coupling and small size design requirements of the auxiliary power supply architecture. At the same time, through multi-level isolation, filtering and level conversion design, the stability of DC bus output voltage is ensured, laying the foundation for reliable power supply to the drive board, control board and auxiliary load.

[0056] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can specifically be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0057] Example 2: This embodiment provides an external auxiliary power supply method applied to a high-voltage power device including a driver board, a control board, and an auxiliary load, for implementing an external auxiliary power supply system. The system includes an AC / DC conversion module, a DC bus, a first isolation level conversion module, a second isolation level conversion module, and a timing interlock module. A timing control switch S is provided between the timing interlock module and the control board. The sampling terminal of the timing interlock module is electrically connected to the negative voltage output terminal of the first isolation level conversion module. Using the timing interlock module as the execution entity, the method includes: When the AC / DC conversion module receives an AC signal and outputs an isolated DC signal to the DC bus based on the AC signal, the first isolation level conversion module performs isolation level conversion on the isolated DC signal to power on the driver board, and the second isolation level conversion module performs isolation level conversion on the isolated DC signal to power on the auxiliary load. Receive isolated DC signals from the DC bus; The negative turn-off bias voltage signal is acquired in real time based on the negative voltage output terminal; The shutdown determination is made based on the negative shutdown bias voltage signal and the preset safety threshold. When the determination meets the preset power supply conditions, the timing control switch S is closed, and then the control board is powered on based on the isolated DC signal.

[0058] Optionally, when it is determined that the preset power supply conditions are met, the timing control switch S is kept in the open state, so that the control board remains unpowered, and the shutdown determination is performed in real time until the preset power supply conditions are met.

[0059] The external auxiliary power supply method provided in this embodiment is based on an external auxiliary power supply system. Using a timing interlocking module as the execution entity, after the AC / DC conversion module outputs an isolated DC signal, and the first and second isolated level conversion modules power on the driver board and auxiliary load respectively, the timing interlocking module receives the isolated DC signal from the DC bus, acquires and determines the negative turn-off bias voltage signal in real time, and powers on the control board only when the conditions are met. This method strictly follows the timing logic of prioritizing driver board power-on. Through the actions of the corresponding hardware modules, precise control of the power-on sequence is achieved, avoiding uncertainties such as delays and crashes present in software control. This ensures that the gate of the high-voltage power device always receives a reliable reverse turn-off voltage before receiving control commands from the control board. From a methodological perspective, this guarantees the safety of auxiliary power supply in high-voltage scenarios. Furthermore, the execution process of the method is highly compatible with the system hardware, and the connection between each step relies on the electrical connection and signal transmission of the hardware modules, ensuring the stability and operability of the power supply method.

[0060] The auxiliary power supply system and method provided in Embodiments 1 and 2 ensure the safety and high accuracy of the power-on timing through the hardware design of timing interlocking logic. This embodiment features a timing interlocking hardware circuit deeply integrated with an external centralized auxiliary power supply architecture. The timing interlocking module connects to the DC bus, the first isolation level conversion module, and the control board power supply branch. A hardware voltage comparator monitors the negative turn-off bias voltage of the driver board in real time. Based on a preset safety threshold, it automatically determines the turn-off and controls the on / off state of the timing control switch. This hardware logic design ensures that the SiCMOSFET gate driver board always has a reliable turn-off bias voltage before receiving control commands from the control board, improving the reliability of the driver board's power supply at the hardware level and completely solving the control problem of power unit power-on timing in high-voltage scenarios. This hardware-based timing interlocking design replaces conventional software delay schemes, eliminating control uncertainties during software crashes and startup code loading. It achieves zero-risk physical isolation at the moment of power-on in 10kV high-voltage scenarios and can control the stability of the drive voltage within ±0.1V, completely avoiding the problem of power device mis-triggering caused by improper power-on timing at the hardware level.

[0061] Example 3: This embodiment takes a power unit based on 10kV SiC MOSFET as the application object and conducts an experimental verification of an external auxiliary power supply system provided in this embodiment under a DC bus voltage of 5000V. It details the working process and effect verification results of the auxiliary power supply system, and elaborates on the technical advantages and core design points of this embodiment.

[0062] Specifically, the external auxiliary power supply system in this embodiment is applied to a 10kV SiC MOSFET power unit that includes a driver board, a control board, and an auxiliary load. The auxiliary power supply system is connected to a single-phase 220V AC mains power supply as an AC signal input. After multi-stage power conversion, isolation, and level conversion, it provides reliable auxiliary power to each module of the power unit. The specific workflow is as follows: First, system initialization is performed: the single-phase 220V mains power is connected to the primary side of the power frequency isolation submodule of the system. The power frequency isolation submodule completes the electrical isolation from the mains power side. At the same time, the insulation status and circuit connection status of the AC / DC conversion submodule, each isolation level conversion module, timing interlock module and power unit in the auxiliary power supply system are detected. After confirming that there are no short circuits or open circuits in each module and that the auxiliary power supply system as a whole is in a safe working condition, the power conversion stage begins.

[0063] Next, DC power is established: the received AC mains signal is converted into an isolated AC signal by the power frequency isolation submodule and output to the AC-DC conversion submodule. The isolated AC signal is rectified into a DC signal by the full-bridge rectifier unit in the AC-DC conversion submodule, filtered and smoothed by the first support capacitor, and then inverted into a high-frequency AC signal by the high-frequency inverter unit. The high-frequency AC signal is filtered to remove harmonic interference by the filter unit, and then isolated and transformed again by the high-frequency transformer unit. It is then rectified into a DC signal by the high-frequency rectifier unit, and finally filtered and smoothed a second time by the second support capacitor. A stable DC voltage is established at the DC bus of the auxiliary power supply system, providing a stable energy source for the subsequent first isolation level conversion module, second isolation level conversion module and timing interlock module.

[0064] Finally, auxiliary power supply output is achieved: the first isolation level conversion module and the second isolation level conversion module draw power from the DC bus respectively, and each performs independent isolation level conversion on the isolated DC signal of the DC bus. The first isolation level conversion module outputs a dedicated DC voltage adapted to the operation of the driver board to power on the driver board, and the second isolation level conversion module outputs a DC voltage adapted to the operation of the auxiliary load to power on the auxiliary load. During this process, the timing interlocking module draws power from the DC bus synchronously and obtains the negative shutdown bias voltage signal output by the first isolation level conversion module in real time. It performs shutdown judgment based on a preset safety threshold. When the judgment result meets the preset power supply conditions, it controls the timing control switch to close to power on the control board. Each power supply channel maintains independent electrical isolation to ensure the power supply safety and reliability in high-voltage direct connection scenarios.

[0065] To enable the operation of the power unit, after the system provides stable power to the driver board, control board, and auxiliary load, the driver board enters normal operation. The control board sends control signals to the driver board to drive the 10kV SiC MOSFET power unit to operate normally under a 5000V DC bus voltage. During operation, key electrical signals such as the drain-source voltage, drain current, and drive voltage of the SiC MOSFET are monitored in real time using an oscilloscope, and the system operating status is recorded.

[0066] After completing the above-described workflow under the 5000V DC bus voltage condition, the system's performance was tested and analyzed. The verification results show that the external auxiliary power supply system exhibits good operational stability and reliability. The specific verification results are as follows: The power supply voltage of the drive circuit remains stable, and the amplitude and timing of the drive voltage waveform meet the design requirements. There are no undervoltage, voltage jitter or abnormal fluctuations, which proves that the auxiliary power supply system of this embodiment can provide continuous and reliable energy support for the drive board and meet the high stability requirements of the 10kV SiC MOSFET power unit for the power supply of the drive board. The drain-source voltage and drain current waveforms of the SiC MOSFET maintain a good correspondence with the drive signal waveform. The drive signal can accurately act on the SiC MOSFET power device. No additional electromagnetic interference is introduced due to the unstable auxiliary power supply, and no power device malfunction occurs. This verifies the accuracy and anti-interference of the auxiliary power supply system in this embodiment. Throughout the experiment, no obvious electromagnetic coupling or mutual interference was observed between the external auxiliary power supply system and the 10kV SiC MOSFET power unit. The operating states of each power supply module and each board of the power unit were independent and stable, proving that the external centralized power supply method of the auxiliary power supply system in this embodiment has good engineering feasibility and system reliability in application scenarios with high voltage direct connection and few cascaded modules.

[0067] Throughout the experiment, none of the modules in the auxiliary power supply system of this embodiment experienced insulation breakdown, partial discharge, or common-mode current interference. It was able to continuously and stably provide auxiliary power to the 10kV SiC MOSFET power unit under 5000V high-voltage DC bus conditions, effectively ensuring the normal operation of the drive circuit and control circuit, and fully meeting the efficiency and reliability requirements of the auxiliary power supply system for 10kV direct-connected power electronic devices.

[0068] This embodiment effectively improves the power supply reliability of high-voltage power devices through the topology design of an external centralized auxiliary power supply system. Specifically, for the auxiliary power supply requirements of the 10kV SiC MOSFET power unit, this embodiment designs an external centralized auxiliary power supply topology based on power frequency isolation, AC / DC conversion, high-frequency inverter, high-frequency isolation, DC bus, and multi-channel isolation level conversion, and rationally selects SiC Schottky diodes and GaN... HEMT and other power semiconductor devices, combined with passive components such as low-ESR ceramic multilayer capacitors, NPO high-frequency capacitors, and microstrip-wound filter inductors, achieve efficient conversion from single-phase 220V AC mains power to the auxiliary power supply voltage required by each module of the power unit. The modules work in stages, with layer-by-layer isolation and filtering, ensuring both the stability of the power supply voltage and meeting the insulation and anti-interference requirements of high-voltage scenarios. The external centralized power supply method under this topology achieves multi-level electrical isolation through a power frequency isolation submodule and a high-frequency transformer unit. After multi-stage filtering and rectification, a stable isolated DC signal is generated, which is then used by the first and second isolation level conversion modules to provide suitable isolated DC voltages to the driver board, control board, and auxiliary loads. This avoids the electromagnetic coupling and signal interference risks easily introduced by multi-stage DC / DC converters in self-powered power supply schemes, ensuring the stable operation of the 10kV SiC MOSFET power unit in high-voltage direct-connection scenarios from the power supply link design perspective. Furthermore, the high-isolation power frequency isolation submodule structural design provides technical advantages such as high insulation performance and low electromagnetic coupling.

[0069] Example 4: Based on the above embodiments of the external auxiliary power supply method, another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the external auxiliary power supply method of any embodiment of the present invention.

[0070] For example, in this embodiment, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the terminal device.

[0071] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0072] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0073] Example 5: Based on the above-described method embodiments, another embodiment of the present invention provides a computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the external auxiliary power supply method described in any of the above-described method embodiments of the present invention.

[0074] The modules / units integrated in the device / terminal equipment, if implemented as software functional units and sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0075] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An external auxiliary power supply system, characterized in that, This system is applied to high-voltage power devices, which include a drive board, a control board, and an auxiliary load. The system includes an AC / DC conversion module, a DC bus, a first isolation level conversion module, a second isolation level conversion module, and a timing interlock module, wherein: The AC / DC conversion module is used to receive AC signals and output isolated DC signals based on the AC signals, and output them to the DC bus. The DC bus is used to receive the isolated DC signal and transmit it to the first isolation level conversion module, the second isolation level conversion module and the timing interlocking module respectively; The first isolation level conversion module is used to perform isolation level conversion on the isolated DC signal to power on the driver board; the second isolation level conversion module is used to perform isolation level conversion on the isolated DC signal to power on the auxiliary load. A timing control switch is provided between the timing interlocking module and the control board, and the sampling terminal of the timing interlocking module is electrically connected to the negative voltage output terminal of the first isolation level conversion module. The timing interlocking module is used to acquire the negative turn-off bias voltage signal in real time based on the negative voltage output terminal, and to make a turn-off determination based on the negative turn-off bias voltage signal and a preset safety threshold. When the determination meets the preset power supply conditions, it controls the timing control switch to close, and then powers on the control board based on the isolated DC signal.

2. The external auxiliary power supply system as described in claim 1, characterized in that, The AC / DC conversion module includes a power frequency isolation submodule and an AC / DC conversion submodule, wherein: The power frequency isolation submodule is used to receive the AC signal and output an isolated AC signal to the AC-DC conversion submodule; The AC / DC conversion submodule is used to convert the isolated AC signal to an isolated DC signal and transmit it to the DC bus.

3. An external auxiliary power supply system as described in claim 2, characterized in that, The power frequency isolation submodule includes an iron core, a primary side, a secondary side, an inner shielding layer, and an outer shielding layer, wherein: The primary side includes a first primary winding and a second primary winding connected in series, and the secondary side includes a secondary winding. The first primary winding, the second primary winding, and the secondary winding are respectively wound on the iron core. The original side is used to receive the AC signal; The secondary side is used to electrically connect to the AC / DC conversion submodule, and the secondary side is used to transmit the isolated AC output signal generated based on the AC signal to the AC / DC conversion submodule; There is electrical insulation between the inner shielding layer and the outer shielding layer; The inner shielding layer is tightly attached to the surface of the primary side and is electrically connected to the protective ground. The inner shielding layer is used to discharge the primary side common-mode current generated on the primary side to the protective ground. The outer shielding layer is tightly attached to the secondary side surface and is electrically connected to the power ground of the high-voltage power device. The outer shielding layer is used to discharge the secondary common-mode current generated on the secondary side to the power ground.

4. An external auxiliary power supply system as described in claim 3, characterized in that, The primary side of the power frequency isolation submodule also includes a first voltage divider resistor and a second voltage divider resistor; wherein: the first voltage divider resistor is connected in parallel across the two ends of the first primary winding, and the second voltage divider resistor is connected in parallel across the two ends of the second primary winding.

5. An external auxiliary power supply system as described in claim 3, characterized in that: An air gap is provided between the inner shielding layer and the outer shielding layer to maintain electrical insulation between them.

6. An external auxiliary power supply system as described in claim 2, characterized in that: The AC / DC conversion submodule includes a full-bridge rectifier unit, a first supporting capacitor, a high-frequency inverter unit, a filter unit, a high-frequency transformer unit, a high-frequency rectifier unit, and a second supporting capacitor, wherein: The receiving end of the full-bridge rectifier unit is used to receive the isolated AC signal; The first output terminal of the full-bridge rectifier unit is electrically connected to the first terminal of the first supporting capacitor, the second output terminal of the full-bridge rectifier unit is electrically connected to the second terminal of the first supporting capacitor, the first output terminal of the full-bridge rectifier unit is electrically connected to the first receiving terminal of the high-frequency inverter unit, and the second output terminal of the full-bridge rectifier unit is electrically connected to the second receiving terminal of the high-frequency inverter unit. The first output terminal of the high-frequency inverter unit is electrically connected to the first terminal of the filter unit, and the second output terminal of the high-frequency inverter unit is electrically connected to the second terminal of the filter unit. The second end of the filtering unit is electrically connected to the first receiving end of the high-frequency transformer unit, and the third end of the filtering unit is electrically connected to the second receiving end of the high-frequency transformer unit. The first output terminal of the high-frequency transformer unit is electrically connected to the first receiving terminal of the high-frequency rectifier unit, and the second output terminal of the high-frequency transformer unit is electrically connected to the second receiving terminal of the high-frequency rectifier unit. The first output terminal of the high-frequency rectifier unit is electrically connected to the first terminal of the second supporting capacitor, and the second output terminal of the high-frequency rectifier unit is electrically connected to the second terminal of the second supporting capacitor. The first output terminal and the second output terminal of the high-frequency rectifier unit are respectively electrically connected to the DC bus. The first output terminal and the second output terminal of the high-frequency rectifier unit are used to transmit the obtained isolated DC signal to the DC bus.

7. An external auxiliary power supply system as described in claim 6, characterized in that: The filtering unit includes a filter inductor and a filter capacitor, wherein: The first end of the filter inductor serves as the first end of the filter unit, the second end of the filter inductor is electrically connected to the first end of the filter capacitor, the second end of the filter capacitor serves as the second end of the filter unit, and the second end of the filter inductor serves as the third end of the filter unit.

8. An external auxiliary power supply system as described in claim 1, characterized in that: The timing interlocking module is also used to control the timing control switch to remain in the off state when it is determined that the preset power supply conditions are not met, so that the control board remains in the unpowered state, and to make a shutdown determination in real time until the preset power supply conditions are met.

9. An external auxiliary power supply method, characterized in that, An external auxiliary power supply system is applied to a high-voltage power device including a driver board, a control board, and an auxiliary load. The system includes an AC / DC conversion module, a DC bus, a first isolation level conversion module, a second isolation level conversion module, and a timing interlock module. A timing control switch is provided between the timing interlock module and the control board. The sampling terminal of the timing interlock module is electrically connected to the negative voltage output terminal of the first isolation level conversion module. Using the timing interlock module as the execution entity, the method includes: When the AC / DC conversion module receives an AC signal and outputs an isolated DC signal to the DC bus based on the AC signal, the first isolation level conversion module performs isolation level conversion on the isolated DC signal to power on the driver board, and the second isolation level conversion module performs isolation level conversion on the isolated DC signal to power on the auxiliary load. Receive isolated DC signals from the DC bus; The negative turn-off bias voltage signal is acquired in real time based on the negative voltage output terminal; The shutdown determination is made based on the negative shutdown bias voltage signal and the preset safety threshold. When the preset power supply conditions are met, the timing control switch is closed, and the control board is powered on based on the isolated DC signal.

10. A terminal device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements the external auxiliary power supply method as described in any one of claims 9.

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