Overvoltage automatic cut-off device for high-frequency switching power supply module

Abstract

The invention discloses a high-frequency switching power supply module overvoltage automatic removal device which adopts a hardware architecture completely independent of a high-frequency switching power supply module and a system monitor, state acquisition, logic judgment, fault removal and power supply form a closed loop, and decoupling of an overvoltage protection function and system main monitoring is realized. A threshold adjusting module of the self-adaptive control module dynamically corrects an overvoltage threshold in combination with real-time temperature and an aging coefficient, misjudgment of a fixed threshold due to module temperature excursion and long-term aging is avoided, overvoltage judgment better fits the actual operation characteristics of the module, meanwhile, a fault pre-judgment module is based on logic judgment of real-time voltage and the dynamic threshold, and the fault pre-judgment accuracy is improved. The overvoltage state can be accurately identified; besides, the fault removal module terminates an overvoltage generation source by cutting off module energy input and synchronously eliminates an overvoltage signal existing at the output end of the module, so that the situation that downstream equipment is continuously damaged by module residual energy after input is cut off is avoided, and the damage risk of overvoltage is effectively reduced.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to an automatic overvoltage cutoff device for a high-frequency switching power supply module. Background Technology

[0002] In power systems, the 48V DC communication power supply system in substations is the core power source ensuring the reliable operation of critical equipment such as protection devices, automation devices, and communication transmission equipment. High-frequency switching power supply modules, as a core component of this system, perform the dual functions of converting AC power to DC power for substation use and charging batteries. Their operational stability directly determines the safety of the power grid. To improve system redundancy, high-frequency switching power supply modules are generally configured with multiple modules operating in parallel. However, in recent years, accidents causing damage to power grid equipment due to abnormally high output voltage of a single module have occurred frequently, becoming a major hidden danger to the safe operation of the power grid.

[0003] To address the overvoltage protection requirements of high-frequency switching power supply modules, existing technologies primarily employ a built-in voltage sampling unit within the module. This unit converts the analog output voltage signal into a digital signal, which is then transmitted to a monitor. The monitor detects the voltage and, when the received voltage data exceeds a threshold, initiates a power-off operation to achieve overvoltage protection. However, this solution relies on the normal operation of the monitor. If the monitor malfunctions, experiences a crash, program error, or power failure, it will be unable to receive the module's voltage sampling data or send a cut-off command, rendering the overvoltage protection function ineffective. Furthermore, the communication bus between the module and the monitor is susceptible to strong electromagnetic interference from substations, aging cables, and loose connections, leading to communication interruptions and preventing protection from being triggered.

[0004] Therefore, how to improve the reliability of DC communication power supply systems in substations is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide an automatic overvoltage cut-off device for high-frequency switching power supply modules, which can improve the reliability of DC communication power supply systems in substations.

[0006] In a first aspect, embodiments of this application provide an automatic overvoltage cutoff device for a high-frequency switching power supply module, connected to the high-frequency switching power supply module. The device includes: a status acquisition module for acquiring the operating status of the high-frequency switching power supply module, an adaptive control module, a fault cutoff module for cutting off the energy supply of the high-frequency switching power supply module and eliminating its overvoltage output, and a power supply module for supplying power to each module. The status acquisition module includes a voltage acquisition module and a temperature acquisition module; The adaptive control module includes a threshold adjustment module and a fault prediction module. The threshold adjustment module is used to dynamically correct the overvoltage threshold based on the real-time temperature generated by the temperature acquisition module and the preset aging coefficient. The fault prediction module is used to perform overvoltage logic judgment based on the real-time voltage generated by the voltage acquisition module and the overvoltage threshold. If it is determined to be overvoltage, the fault clearing module is triggered.

[0007] In one embodiment, the voltage acquisition module includes: The first voltage acquisition unit is used to acquire the output voltage of the high-frequency switching power supply module; The second voltage acquisition unit is used to acquire the DC bus voltage of the high-frequency switching power supply module; The fault prediction module includes a threshold judgment unit, which is used to determine whether the output voltage reaches the overvoltage threshold; if the overvoltage threshold is reached, the difference between the output voltage and the DC bus voltage is calculated; if the difference is higher than the first threshold, it is determined that a single module is overvoltage and a multi-level fault isolation module is triggered; if the difference is not higher than the second threshold, it is determined that the bus is overvoltage and an alarm is triggered.

[0008] In one embodiment, the fault prediction module further includes: a fusion processing unit; The fusion processing unit is used to fuse the output voltage and the DC bus voltage using a Kalman filter algorithm to obtain a filtered fused value of the output voltage and a fused value of the DC bus voltage. The threshold judgment unit is used to determine whether the output voltage fusion value reaches the overvoltage threshold; if it reaches the overvoltage threshold, it calculates the difference between the output voltage fusion value and the DC bus voltage fusion value; if the difference is higher than the first threshold, it is determined that a single module is overvoltage and triggers multi-level fault isolation module; if the difference is not higher than the second threshold, it is determined that the bus is overvoltage and triggers an alarm.

[0009] In one embodiment, the first voltage acquisition unit acquires the output voltage via a series reverse-blocking diode.

[0010] In one embodiment, the reverse-blocking diode is a Schottky barrier diode.

[0011] In one embodiment, an RC snubber circuit is connected in parallel across the reverse stop diode.

[0012] In one embodiment, the second voltage acquisition unit acquires the DC bus voltage via a Hall voltage sensor.

[0013] In one embodiment, the power supply module is a dual DC-DC power supply.

[0014] In one embodiment, the fault clearing module includes: An AC circuit breaker connected in series with the AC input terminal of the high-frequency switching power supply module serves as a primary disconnection unit, used to disconnect the AC input power of the high-frequency switching power supply module. A solid-state relay connected in parallel to the DC output terminal of the high-frequency switching power supply module serves as a secondary cut-off unit, used to short-circuit the overvoltage DC signal output by the high-frequency switching power supply module to the protective ground. Accordingly, the fault prediction module includes a graded triggering unit, which is used to identify the overvoltage logic judgment result. If the overvoltage logic judgment result is a slight overvoltage, a triggering command is sent to the secondary cutoff unit; if the overvoltage logic judgment result is a severe overvoltage, a coordinated triggering command is sent to both the primary cutoff unit and the secondary cutoff unit.

[0015] In one embodiment, the solid-state relay is a zero-voltage turn-on relay.

[0016] The high-frequency switching power supply module overvoltage automatic cutoff device provided in this application adopts a hardware architecture completely independent of the high-frequency switching power supply module and system monitor. Status acquisition, logic judgment, fault clearing, and power supply are all self-contained closed loops, achieving decoupling of overvoltage protection function from the main system monitoring. Moreover, the threshold adjustment module of the adaptive control module dynamically corrects the overvoltage threshold by combining real-time temperature and aging coefficient, avoiding misjudgment caused by fixed threshold due to module temperature drift and long-term aging, making the overvoltage judgment more in line with the actual operating characteristics of the module. At the same time, the fault prediction module can accurately identify the overvoltage state based on the logic judgment of real-time voltage and dynamic threshold. In addition, the fault clearing module focuses on the dual objectives of cutting off energy supply and eliminating overvoltage output. It terminates the source of overvoltage generation by cutting off the module's energy input and simultaneously eliminates the overvoltage signal already existing at the module's output, avoiding the situation where the residual energy of the module continues to harm downstream equipment after only cutting off the input, effectively reducing the risk of damage from overvoltage.

[0017] Therefore, the high-frequency switching power supply module overvoltage automatic cut-off device provided in this application can make up for the problems of overvoltage hazards in high-frequency switching power supply modules and insufficient reliability of existing protection schemes in the existing solutions, and realize accurate and reliable protection of substation DC communication power supply systems.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1A schematic diagram of the working principle of a high-frequency switching module is shown. Figure 2 This paper shows a schematic diagram of an automatic overvoltage cutoff device for a high-frequency switching power supply module provided in an embodiment of this application. Detailed Implementation

[0020] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the accompanying drawings and embodiments. Although the embodiments of this application provide method operation instruction steps as shown in the following embodiments or drawings, more or fewer operation instruction steps may be included in the method based on conventional or non-inventive effort. In steps where there is no logically necessary causal relationship, the execution order of these steps is not limited to the execution order provided in the embodiments of this application. In actual processing or when the device executes, the method may be executed sequentially or in parallel according to the method shown in the embodiments or drawings.

[0022] Example 1: The high-frequency switching power supply module is internally equipped with overvoltage protection. Its principle is to sample the output voltage of each module, convert the electrical signal into a digital signal, and transmit it to the monitor via RS-485. When the output voltage exceeds the alarm value, the monitor issues a command to control the module to cut off the module's output. Figure 1 The diagram shows the working principle of a high-frequency switching module. This embodiment proposes an automatic overvoltage cutoff device for a high-frequency switching power supply module. This device works in conjunction with the high-frequency switching power supply module and is an external intelligent cutoff device independent of the internal overvoltage protection unit built into the high-frequency switching power supply module. Together with the internal overvoltage protection unit, it realizes an intelligent dual protection system for the high-frequency switching power supply module.

[0023] Please refer to Figure 2 , Figure 2 A schematic diagram of the overvoltage automatic cutoff device for the high-frequency switching power supply module provided in this embodiment is shown. Figure 2 As shown, the device mainly includes four core modules: a status acquisition module, an adaptive control module, a fault isolation module, and a power supply module.

[0024] In the automatic overvoltage cutoff device for high-frequency switching power supply modules, the status acquisition module is responsible for capturing key operating parameters of the high-frequency switching power supply module in real time, providing reliable data support for the subsequent logical judgment of the adaptive control module and the action triggering of the fault cutoff module.

[0025] The core components of the status acquisition module include two main acquisition modules: a voltage acquisition module and a temperature acquisition module. The voltage acquisition module can be directly connected to the output terminals of the high-frequency switching power supply module, while the temperature acquisition element (not limited to sensor type) of the temperature acquisition module is deployed on or near the surface of the core heat-generating component of the high-frequency switching power supply module.

[0026] The voltage acquisition module is used to acquire the output voltage of the high-frequency switching power supply module, avoiding bus voltage interference and ensuring that the acquired values ​​accurately reflect the output status of a single module. The temperature acquisition module is used to acquire the real-time operating temperature of the high-frequency switching power supply module, focusing on monitoring the surface temperature of power devices (such as IGBTs and rectifier bridges) to reflect the module's heating status. This embodiment does not limit the specific types of components used for the voltage and temperature acquisition modules; they can be selected based on the specific requirements of the actual application scenario, and will not be elaborated further here.

[0027] It should be noted that when the status acquisition module is connected to the high-frequency switching power supply module, there is no need to modify the original circuit of the high-frequency switching power supply module. It can be connected to the output terminal of the module only through the external terminal, avoiding potential hazards to the original system. At the same time, the modular design can be adapted to different models of high-frequency switching power supply modules without large-scale modification of the original system, and is suitable for multi-module parallel operation scenarios in substations.

[0028] The signal output terminals of the voltage and temperature acquisition units are connected to the adaptive control module. The adaptive control module is the core decision-making unit, undertaking the dual functions of dynamically optimizing overvoltage standards and accurately judging overvoltage states. By integrating real-time data from the status acquisition module, it realizes intelligent adjustment of overvoltage protection logic, avoiding false alarms and missed alarms caused by fixed thresholds, and ensuring the timeliness and accuracy of fault clearing actions.

[0029] The core function of the adaptive control module is to dynamically optimize the protection strategy based on the real-time operating status of the module, accurately identify overvoltage faults, and trigger the disconnection action. Specifically, the adaptive control module includes a threshold adjustment module and a fault prediction module. The threshold adjustment module receives real-time temperature data (reflecting the current heating state of the module) from the temperature acquisition unit in the status acquisition module, calculates a preset aging coefficient (generated based on the module's cumulative running time, historical overtemperature counts, and overvoltage event frequency, ranging from 0 to 1; the larger the coefficient, the more severe the aging; the specific calculation formula is not limited in this embodiment), and dynamically corrects the overvoltage threshold according to the real-time temperature generated by the temperature acquisition module and the preset aging coefficient.

[0030] This embodiment does not limit the specific correction logic, but only provides a working condition-threshold correlation algorithm for reference. Its core logic may include, but is not limited to: when the temperature rises (e.g., exceeding 60℃), the withstand voltage of the module's power devices decreases, and the threshold adjustment module lowers the overvoltage threshold by a preset ratio; for example, the threshold is 54V at room temperature and corrected to 52V at high temperature. When the aging coefficient increases (e.g., approaching 1), the performance of components such as module capacitors and semiconductors degrades, and the threshold is lowered accordingly; for example, the threshold is 54V at a low aging coefficient of 0.2 and corrected to 51V at a high aging coefficient of 0.8. When temperature and aging coefficient have a combined effect, a weighted calculation is used, such as a 40% weight for temperature and a 60% weight for aging coefficient, to avoid threshold deviation caused by a single factor. Other overvoltage threshold correction methods can refer to the above logic and will not be elaborated further here.

[0031] The threshold adjustment module breaks through the limitations of traditional fixed overvoltage thresholds. By combining the module's real-time temperature and aging characteristics, it generates a dynamic overvoltage threshold that adapts to the current operating conditions. This solves the problems of protection lag caused by the module's reduced withstand voltage under high temperature / high aging conditions but the use of the original threshold, and false tripping caused by an overly strict threshold under normal temperature / low aging conditions.

[0032] The fault prediction module in the adaptive control module is used to perform overvoltage logic judgment based on the real-time voltage generated by the voltage acquisition module and the overvoltage threshold to determine whether to trigger fault clearing. If overvoltage is detected, the fault clearing module is triggered. The fault prediction module uses the dynamic overvoltage threshold as a benchmark, compares it with the real-time voltage data from the voltage acquisition module, identifies overvoltage, and accurately triggers the fault clearing module after confirming overvoltage to stop the overvoltage hazard. It can also output alarm signals (such as audible and visual alarms) to prompt maintenance personnel to handle the situation, but this is not limited here.

[0033] The adaptive control module can specifically use an STM32 series microcontroller (such as the STM32F103C8T6) as its hardware core. The STM32F103C8T6 microcontroller has strong data processing capabilities and a multi-channel ADC interface, which can receive multiple acquisition signals and multiple data commands, making it easy to configure. Of course, other types of chips can also be used, but this embodiment does not limit this choice.

[0034] The fault isolation module performs a dual function: cutting off the power supply source to the module and eliminating existing overvoltage output. After the adaptive control module detects overvoltage, it physically blocks the module's energy input, eliminates residual overvoltage at the output, terminates the AC input energy to the high-frequency switching power supply module, prevents the module from continuing to generate overvoltage output, and avoids the continuous generation of overvoltage. It then eliminates the overvoltage output and handles any residual overvoltage energy already present at the module's output, such as the high-voltage charge stored in the filter capacitor, to prevent residual overvoltage from impacting downstream equipment after the power supply is cut off. By precisely and quickly terminating the overvoltage hazard and preventing the overvoltage signal from spreading to the DC bus and downstream equipment, such as communication transmission equipment and automation devices, it is a key execution unit for ensuring the safety of the substation's 48V DC communication power supply system.

[0035] Specifically, the fault isolation module is connected to the adaptive control module via an electrical isolation interface (such as opto-isolation or relay isolation) and receives overvoltage trigger commands (which can be digital signals or switching signals) from the adaptive control module. Simultaneously, the fault isolation module is connected in series with the energy input path of the high-frequency switching power supply module (such as the AC input terminal or DC bus input terminal), maintaining continuity under normal conditions to ensure normal power supply to the module. Upon overvoltage triggering, this path is cut off, thereby cutting off the energy supply to the high-frequency switching power supply module and stopping the continuous generation of overvoltage signals at the source. The fault isolation module is connected in parallel or selectively connected to the DC output terminal of the module. Under normal conditions, it does not affect the output characteristics of the high-frequency switching power supply module. Upon triggering, it handles residual overvoltage through energy discharge or isolation mechanisms, safely releasing or isolating residual overvoltage energy (such as capacitor energy storage or inductor freewheeling current) already present at the module output terminal, preventing residual overvoltage from impacting downstream equipment (such as communication equipment and protection devices) after the energy supply is cut off.

[0036] The circuit configuration of the fault isolation module can be flexibly selected based on system voltage level, response speed requirements, and cost budget. The core functionality must meet the goals of rapid disconnection and safe elimination. For example, a driven circuit breaker or thyristor can be selected to achieve energy disconnection, while a discharge transistor or varistor clamping can be used to eliminate overvoltage output. This embodiment only uses the above circuit configuration as an example; the selection of other circuit configurations can refer to the description in this embodiment and will not be elaborated further here.

[0037] The power supply module connects to all functional modules within the automatic overvoltage cutoff device of the high-frequency switching power supply module, providing continuous and stable power. All output circuits of the power supply module and each functional module can have built-in short-circuit and overvoltage protection functions, so that in the event of a fault in one circuit (such as a short circuit), only the power supply to that circuit is cut off, without affecting the operation of other modules, thus improving system redundancy. The power supply module preferentially draws power from the stable energy source of the protected system, avoiding drawing power from the output terminal of the high-frequency switching power supply module itself, to prevent power interruption in the event of a fault in the high-frequency switching power supply module. Possible power source scenarios include, but are not limited to: 48V DC communication bus in substations, 220V AC power supply for station use, etc.

[0038] In this embodiment, the specific circuit configuration of the power supply module is not limited and can be flexibly selected according to the device's power requirements, reliability requirements, and installation environment. For example, an LDO low-dropout linear regulator or an AC-DC switching power supply can be used. In one embodiment, the power supply module can specifically be a DC-DC dual-channel power supply. The DC-DC dual-channel power supply can output two independent and adjustable DC voltages, such as one 5V supply for the control module and acquisition module, and the other 12V supply for the fault isolation module drive circuit. This eliminates the need for multiple single-channel power supplies, simplifying the device's power supply architecture. At the same time, the two outputs can be configured with overload protection and overvoltage protection respectively. When a load on one channel fails (such as a momentary short circuit in the fault isolation module), only the power supply to that channel is cut off, without affecting the operation of the core units such as the control module and acquisition module.

[0039] Based on the above description, the high-frequency switching power supply module overvoltage automatic cutoff device provided in this embodiment adopts a hardware architecture that is completely independent of the high-frequency switching power supply module and the system monitor. Status acquisition, logic judgment, fault clearing, and power supply are all self-contained closed loops, realizing the decoupling of overvoltage protection function from the main system monitoring. Moreover, the threshold adjustment module of the adaptive control module dynamically corrects the overvoltage threshold by combining real-time temperature and aging coefficient, avoiding misjudgment caused by fixed threshold due to module temperature drift and long-term aging, making the overvoltage judgment more in line with the actual operating characteristics of the module. At the same time, the fault prediction module can accurately identify the overvoltage state based on the logic judgment of real-time voltage and dynamic threshold. In addition, the fault clearing module focuses on the dual goals of cutting off energy supply and eliminating overvoltage output. It terminates the source of overvoltage generation by cutting off the module's energy input and simultaneously eliminates the overvoltage signal already present at the module's output, avoiding the situation where the residual energy of the module continues to harm downstream equipment after only cutting off the input, effectively reducing the risk of damage from overvoltage.

[0040] Example 2: Based on the above embodiments, in order to accurately distinguish the root cause of overvoltage and realize the targeted removal of faulty modules, this embodiment proposes to locate the root cause of overvoltage by independently acquiring the output voltage of the module and the DC bus voltage, and then locating the root cause of overvoltage based on the difference between the two, thereby avoiding the misjudgment problem of traditional single voltage acquisition.

[0041] Specifically, the voltage acquisition module includes a first voltage acquisition unit and a second voltage acquisition unit. The first voltage acquisition unit acquires the output voltage of the high-frequency switching power supply module, reflecting the output state of the high-frequency switching power supply module itself. The second voltage acquisition unit acquires the DC bus voltage of the high-frequency switching power supply module, reflecting the common voltage state of the entire system. Correspondingly, a threshold judgment unit is set in the fault prediction module. The threshold judgment unit is specifically used to determine whether the output voltage reaches the overvoltage threshold. If the output voltage does not reach the overvoltage threshold, it is determined to be normal operation, and no further action is required. If the output voltage reaches the overvoltage threshold, the next step is differential analysis, which calculates the difference between the output voltage and the DC bus voltage. If the difference is higher than the first threshold (e.g., 2V), it is determined to be a single module overvoltage, triggering a multi-level fault isolation module. If the difference is not higher than the second threshold (e.g., 1V), it is determined to be a bus overvoltage, triggering an alarm.

[0042] Under normal operating conditions, the output voltage of the high-frequency switching power supply module is basically the same as the DC bus voltage (the difference is only the line voltage drop, usually ≤0.5V). When the module output voltage exceeds the limit, by calculating the difference between the output voltage and the DC bus voltage, two overvoltage scenarios can be accurately distinguished: If the difference is greater than the first threshold, it means that only the output voltage of this module is abnormally high, while the bus voltage is still within the normal range. For example, the sampling capacitor inside the module burns out, causing the output to surge to 84V. The bus voltage is not over-limited because other modules share the current. It is determined that a single high-frequency switching power supply module is over-voltage. If the difference is less than or equal to the second threshold, it means that the module output voltage exceeds the limit because the overall bus voltage has increased. For example, if other faulty high-frequency switching power supply modules pull up the bus voltage, the output of this high-frequency switching power supply module will passively increase with the bus voltage, which is determined to be bus overvoltage.

[0043] If the overvoltage is in a single module, a multi-level fault isolation module is triggered, cutting off the AC input of the module and discharging the residual overvoltage. Only the faulty module is isolated, without affecting the operation of other normal modules. If the overvoltage is in the bus, a single module isolation is not triggered to avoid accidentally isolating normal modules. Only an alarm is triggered (such as audible and visual alarms, remote notifications, etc., which are not limited here) to prompt maintenance personnel to investigate system-level problems, such as sudden load reduction or multiple module anomalies.

[0044] Substation high-frequency switching power supply modules commonly employ a multi-module parallel configuration, with all module outputs connected to the same DC bus. If only the module output voltage is collected, when the bus experiences an overall overvoltage due to a fault in one high-frequency switching power supply module or a system problem, the output voltage of all high-frequency switching power supply modules will passively rise along with the bus. Traditional protection systems would mistakenly interpret this as an overvoltage in all high-frequency switching power supply modules and disconnect them in batches, leading to a power outage in the entire DC communication system. This embodiment, by limiting the collection of bus voltage and calculating the difference, can accurately identify bus overvoltage scenarios, avoid mistakenly disconnecting normal modules, and ensure continuous system power supply.

[0045] Example 3: In this second embodiment, there is no limitation on the specific acquisition devices selected for the first voltage acquisition unit and the second voltage acquisition unit. For example, the first voltage acquisition unit can be selected from voltage divider resistor acquisition components, integrated voltage acquisition chips, etc., and the second voltage acquisition unit can be selected from high-precision voltage divider acquisition modules, isolated voltage transmitters, etc.

[0046] The first voltage acquisition unit acquires the output voltage of the high-frequency switching power supply module itself. Since multiple modules in the substation system are connected in parallel to the same bus, if the module output voltage is directly acquired, the reverse voltage on the bus side may flow back into the acquisition circuit, causing the acquired value to be distorted. To avoid this situation, in one embodiment, the first voltage acquisition unit can acquire the output voltage by connecting a series reverse-blocking diode. In the acquisition circuit of the first voltage acquisition unit, a diode with unidirectional conductivity is connected in series. The reverse-blocking diode is connected in series in the line from the positive terminal of the module output (OUT+) to the positive terminal of the signal input of the first voltage acquisition unit (only one diode needs to be connected in series, no parallel connection is required). The anode (+) of the diode faces the positive terminal of the module output, and the cathode (-) faces the positive terminal of the signal input of the acquisition unit. Utilizing the forward conduction and reverse cutoff characteristics of diodes, when the module outputs voltage normally, the current conducts along the forward path from the high-frequency switching power supply module output terminal → reverse blocking diode → first voltage acquisition unit, allowing the acquisition unit to accurately acquire the module's own output voltage. When reverse voltage or reverse current occurs on the bus side, the diode reverse cuts off, blocking the conduction of bus interference to the acquisition circuit, ensuring that the acquired value only reflects the true output state of a single module, and providing an accurate data basis for subsequent differentiation between module overvoltage and bus overvoltage.

[0047] The reverse protection diode can be a Schottky barrier diode, which is based on the barrier structure of metal and semiconductor contact and has an extremely low forward voltage drop, which can significantly reduce voltage acquisition deviation. Of course, other types of diodes can also be used, such as ordinary silicon rectifier diodes, fast recovery diodes, etc., but this embodiment does not limit them.

[0048] To suppress voltage spikes caused by reverse recovery during the switching of the Schottky barrier diode (although the reverse recovery time is extremely short, there is still a transient current change), and to avoid spike interference with the voltage acquisition accuracy of the first voltage acquisition unit, while protecting the diode and subsequent voltage divider resistors, ADC chips, and other devices in the acquisition circuit from overvoltage surges, and to meet the stable acquisition requirements of the strong electromagnetic environment in substations, an RC snubber circuit can be connected in parallel across the reverse barrier diode. In the RC snubber circuit, the capacitor can quickly absorb the instantaneous spike energy during diode switching, while the resistor can suppress the LC oscillation formed by the capacitor and the parasitic inductance of the acquisition circuit, further attenuating high-frequency interference, ensuring a smoother output voltage signal from the acquired module, and reducing the impact of spike voltage on the diode's reverse withstand voltage, extending device lifespan, and ensuring the long-term reliable operation of the first voltage acquisition unit.

[0049] The second voltage acquisition unit is used to acquire the common voltage status of the DC bus. Because multiple high-frequency switching power supply modules operate in parallel on the DC bus, there are issues such as high-frequency switching interference, instantaneous overvoltage, and ground loop current. To block strong electrical interference and risks to the bus, the second voltage acquisition unit can acquire the DC bus voltage using a Hall voltage sensor. Specifically, the Hall voltage sensor can draw power from the positive and negative terminals of the DC bus, i.e., it is connected in parallel to the common output terminal of the 48V DC bus of the substation through dedicated terminals. The secondary side signal output terminals (such as OUT+, OUT-) of the Hall voltage sensor are connected to the signal conditioning circuit of the second voltage acquisition unit. The output standard signal (such as 0-5V) is filtered by an RC low-pass filter and then connected to the ADC pin of the STM32 microcontroller to ensure a smooth acquisition signal. The ground terminal of the secondary side of the Hall voltage sensor shares a common ground with the protective ground (GND) of the device control module to ensure a consistent signal reference potential.

[0050] The Hall voltage sensor, based on the Hall effect principle, achieves non-contact acquisition of DC bus voltage through electromagnetic induction. It eliminates the need for direct series or parallel connection to the high-voltage bus circuit. Instead, it utilizes the sensor's magnetic field sensing element to convert the current signal corresponding to the bus voltage into a standard weak electrical signal linearly related to the voltage. This signal is then transmitted to the signal conditioning circuit of the second voltage acquisition unit, where it is filtered and amplified to achieve accurate acquisition of the DC bus voltage. The Hall voltage sensor has a primary-secondary isolation voltage ≥2500V, achieving signal transmission through magnetic coupling. With no direct electrical connection, it completely blocks the conduction of high-voltage bus interference, ground loop current, and transient overvoltage into the acquisition circuit.

[0051] Example 4: The first voltage acquisition unit acquires the output voltage of the module, and the second voltage acquisition unit acquires the DC bus voltage. However, the 48V DC communication power supply system of the substation has problems such as strong interference, fluctuations in the parallel connection of multiple modules, and easy confusion of overvoltage types. Directly using the original acquired voltage for judgment may cause noise to cause the instantaneous peak of the module output voltage to be misjudged as a single module overvoltage, triggering unnecessary disconnection actions and affecting the power supply of the system. At the same time, after the small fluctuations of the bus voltage are combined with the module output voltage, the difference calculation is distorted, which may mistakenly determine the single module overvoltage as the bus overvoltage, resulting in missed fault disconnection.

[0052] To address the issue of high noise levels in the raw data acquisition, which could lead to misjudgments due to overvoltage, this embodiment proposes to further incorporate a fusion processing unit into the fault prediction module.

[0053] The fusion processing unit is mainly used to fuse the output voltage and DC bus voltage using the Kalman filter algorithm, obtaining the filtered fused output voltage value and the fused DC bus voltage value. Specifically, the Kalman filter is based on an iterative logic of prediction and updating. It first predicts the current voltage value based on the historical change patterns of the voltage data, and then corrects it by combining newly acquired voltage data (including noise). Finally, it outputs the filtered fused output voltage value and the fused DC bus voltage value. This process can effectively filter out random noise in the acquired data (such as instantaneous voltage fluctuations caused by electromagnetic interference), while retaining the true trend of voltage change (such as the continuous voltage rise when the module is overvoltaged, and the slow fluctuation of the bus voltage), making the fused voltage value closer to the actual operating conditions and avoiding misjudgments caused by noise in the original data.

[0054] The threshold judgment unit no longer uses the original acquired voltage, but uses the fused voltage value as the judgment basis. Specifically, the threshold judgment unit is used to determine whether the fused output voltage value reaches the overvoltage threshold; if it does not reach it, it is determined to be normal operation, and no further action is required; if it reaches the overvoltage threshold, it calculates the difference between the fused output voltage value and the fused DC bus voltage value; if the difference is higher than the first threshold, it is determined to be a single module overvoltage, triggering multi-level fault isolation of the module; if the difference is not higher than the second threshold, it is determined to be a bus overvoltage, only triggering an alarm, without isolating the module.

[0055] Based on the above introduction, this embodiment proposes a fault prediction module design that combines a fusion processing unit (Kalman filter algorithm) with threshold judgment based on the fusion value. The Kalman filter algorithm dynamically fuses real-time data of the module output voltage and DC bus voltage, effectively filtering out random noise such as strong electromagnetic interference in substations and high-frequency ripple from module switching actions, while preserving the true voltage change trend. This avoids misjudgments and omissions of overvoltage caused by interference with traditional raw data, further reducing the acquisition error between the fused output voltage and DC bus voltage values ​​and significantly improving data reliability. Furthermore, the threshold judgment unit uses the filtered fusion value as a basis, comparing overvoltage thresholds, calculating voltage differences, and triggering hierarchical actions to activate upper-level logic. This accurately distinguishes between individual module overvoltage and bus overvoltage. Even in complex operating conditions with voltage fluctuations caused by multiple modules operating in parallel, it avoids judgment errors caused by normal voltage fluctuations. Moreover, the real-time dynamic adaptation characteristics of the Kalman filter allow for rapid tracking of voltage changes in scenarios of sudden module overvoltage (such as a rapid increase in output voltage to 84V), ensuring timely judgment and action response. This provides accurate and reliable overvoltage protection support for the stable operation of the substation's DC communication power supply system.

[0056] Example 5: Overvoltage faults in high-frequency switching power supply modules can be categorized into two scenarios: mild overvoltage (instantaneous fluctuations) and severe overvoltage (persistent faults). Traditional single-stage tripping solutions (such as using only AC circuit breakers) cannot simultaneously ensure thorough protection and system power supply continuity. To avoid excessive tripping for mild overvoltages, which could affect system power supply, and to prevent incomplete tripping for severe overvoltages, which could lead to residual overvoltage damaging equipment, this embodiment proposes a two-stage architecture for the fault tripping module. This architecture combines primary tripping with secondary tripping with solid-state relays, along with a graded triggering unit in the fault prediction module, forming a precise protection logic that identifies the overvoltage level and corresponds to the tripping action.

[0057] Specifically, the fault clearance module includes: a primary clearance unit and a secondary clearance unit.

[0058] The primary disconnect unit is an AC circuit breaker connected in series with the AC input terminal of the high-frequency switching power supply module. Its core function is to disconnect the AC input power supply to the high-frequency switching power supply module. When triggered, the circuit breaker trips and disconnects the 220V AC input of the module, preventing the module from continuing to generate overvoltage output, thus eliminating the overvoltage risk at its source and fulfilling the core objective of fault disconnection by cutting off the energy supply.

[0059] The secondary cutoff unit is a solid-state relay connected in parallel to the DC output of the high-frequency switching power supply module. Its core function is to short-circuit the overvoltage DC signal output by the high-frequency switching power supply module to the protective ground, quickly eliminating the overvoltage output. When triggered, the solid-state relay conducts, short-circuiting the overvoltage DC signal at the module output to the protective ground, quickly discharging the residual charge of the filter capacitor, suppressing overvoltage spikes, and preventing residual overvoltage from impacting downstream equipment (such as communication transmission equipment, automation devices, etc.) after the AC input is cut off.

[0060] Correspondingly, the fault prediction module includes a graded triggering unit. The graded triggering unit is used to identify the overvoltage logic judgment result. If the overvoltage logic judgment result is a slight overvoltage, a triggering command is sent to the secondary disconnection unit to quickly discharge the overvoltage by shorting to the protection ground. There is no need to disconnect the module's AC input, thus avoiding the interruption of normal power supply. If the overvoltage logic judgment result is a severe overvoltage, a coordinated triggering command is sent to both the primary disconnection unit and the secondary disconnection unit. The circuit breaker trips to cut off the energy supply, and the solid-state relay is simultaneously shorted to discharge the residual overvoltage, forming a dual protection of source disconnection and residual elimination.

[0061] Specifically, a zero-voltage switching (ZVPS) solid-state relay can be selected. A ZVPS solid-state relay only conducts at the instant the AC voltage crosses zero or when the DC voltage approaches zero, thus avoiding voltage surges and electromagnetic interference at the moment of conduction and preventing damage to the device. Of course, other types of relays can also be used; this embodiment does not limit their selection.

[0062] Based on the above introduction, the fault isolation module provided in this embodiment adopts a two-stage architecture of a primary AC circuit breaker and a secondary solid-state relay. It is designed in conjunction with the graded triggering unit of the fault prediction module. By clearly defining the functional division of the two-stage isolation units, the primary AC circuit breaker can cut off the module's AC input to terminate the energy supply, while the secondary solid-state relay can short-circuit the overvoltage DC signal to the protective ground to eliminate residual overvoltage. In cases of minor overvoltage, only the secondary isolation is triggered, avoiding unnecessary power interruptions and ensuring the power supply continuity of the multi-module parallel system. In cases of severe overvoltage, both stages are triggered collaboratively to quickly cut off the energy source and discharge residual overvoltage, preventing the risk of overvoltage propagation damaging communication equipment. This not only meets the core requirements of fault isolation but also achieves differentiated protection through graded triggering.

[0063] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the foregoing disclosed concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A high frequency switching power supply module overvoltage automatic removal device, characterized in that, The device connected to a high-frequency switching power supply module comprises a state acquisition module for acquiring the running state of the high-frequency switching power supply module, an adaptive control module, a fault removal module for cutting off the energy supply of the high-frequency switching power supply module and eliminating the overvoltage output thereof, and a power supply module for supplying power to each module; The state acquisition module comprises a voltage acquisition module and a temperature acquisition module. The adaptive control module comprises a threshold adjustment module and a fault prediction module; the threshold adjustment module is used for dynamically correcting an overvoltage threshold according to the real-time temperature generated by the temperature acquisition module and a preset aging coefficient; and the fault prediction module is used for performing overvoltage logical judgment on the real-time voltage generated by the voltage acquisition module and the overvoltage threshold, and triggering the fault removal module if overvoltage is determined.

2. The apparatus of claim 1, wherein, The voltage acquisition module comprises: A first voltage acquisition unit for acquiring the output voltage of the high-frequency switching power supply module; A second voltage acquisition unit for acquiring the DC bus voltage of the high-frequency switching power supply module. The fault prediction module comprises a threshold judgment unit, which is used for judging whether the output voltage reaches the overvoltage threshold; if the overvoltage threshold is reached, the difference between the output voltage and the DC bus voltage is calculated; if the difference is higher than a first threshold, it is determined that a single module is overvoltage, and a multi-stage fault removal module is triggered; if the difference is not higher than a second threshold, it is determined that the bus is overvoltage, and an alarm is triggered.

3. The apparatus of claim 2, wherein, The fault prediction module further comprises a fusion processing unit. The fusion processing unit is used for performing fusion processing on the output voltage and the DC bus voltage through a Kalman filtering algorithm to obtain a filtered output voltage fusion value and a DC bus voltage fusion value. The threshold judgment unit is used for judging whether the output voltage fusion value reaches the overvoltage threshold; if the overvoltage threshold is reached, the difference between the output voltage fusion value and the DC bus voltage fusion value is calculated; if the difference is higher than the first threshold, it is determined that a single module is overvoltage, and a multi-stage fault removal module is triggered; if the difference is not higher than the second threshold, it is determined that the bus is overvoltage, and an alarm is triggered.

4. The apparatus of claim 2, wherein, The first voltage acquisition unit acquires the output voltage through a series-connected inverse diode.

5. The apparatus of claim 4, wherein, The inverse diode is a Schottky barrier diode.

6. The apparatus of claim 5, wherein, The inverse diode is connected in parallel with an RC absorption circuit across its two ends.

7. The apparatus of claim 2, wherein, The second voltage acquisition unit acquires the DC bus voltage through a Hall voltage sensor.

8. The apparatus of claim 1, wherein, The power supply module is a DC-DC dual-channel power supply.

9. The device of any one of claims 1 to 8, wherein, The fault removal module comprises: An AC air circuit breaker connected in series with the AC input terminal of the high-frequency switching power supply module, serving as a first-stage removal unit, for cutting off the AC input power supply of the high-frequency switching power supply module; A solid-state relay connected in parallel with the DC output terminal of the high-frequency switching power supply module, serving as a second-stage removal unit, for short-circuiting the overvoltage DC signal output by the high-frequency switching power supply module to a protective earth. Correspondingly, the fault pre-judging module comprises a hierarchical triggering unit, which is configured to identify the overvoltage logic judging result, and send a triggering instruction to the secondary cutting unit if the overvoltage logic judging result is mild overvoltage, and send a cooperative triggering instruction to the primary cutting unit and the secondary cutting unit if the overvoltage logic judging result is severe overvoltage.

10. The apparatus of claim 9, wherein, The solid-state relay is a zero-voltage open relay.

Images