A high-voltage leakage protection system for marine propulsion systems

Abstract

This invention relates to the field of marine electrical safety technology, specifically to a high-voltage leakage current protection system for marine propulsion systems. The system includes a dynamic leakage current detection module, a signal processing and control module, a rapid power-off execution module, an environmental adaptability module, and an alarm module. The dynamic leakage current detection module is used to collect the current difference signal, insulation resistance signal, and auxiliary signals of the leakage current protection system in real time. The signal processing and control module is connected to the dynamic leakage current detection module and is used to run a dynamic leakage current detection algorithm to analyze the current difference signal and insulation resistance signal. This invention significantly improves the accuracy and reliability of leakage current detection by setting up dual-channel monitoring and a dynamic threshold algorithm. Combined with rapid power-off and intelligent humidity compensation strategies, it effectively reduces unnecessary downtime and improves system operating efficiency while ensuring safety.

Description

Technical Field

[0001] This invention relates to the field of marine electrical safety technology, and more specifically, to a leakage protection system for high voltage marine propulsion systems. Background Technology

[0002] Electric ship technology is a comprehensive technology that uses electric propulsion systems as its core, replacing traditional fuel power with clean energy sources such as batteries and fuel cells to achieve efficient, low-carbon, and intelligent operation of ships. Its core includes power systems (such as lithium batteries and hydrogen fuel cells), energy management, and intelligent control technologies. Electric ship technology, especially electric outboard motors, is rapidly being promoted as a green and efficient power solution. However, electric outboard motors pose a risk of electrical leakage during use, mainly due to their special working environment. Their high-voltage electrical systems are exposed to the harsh marine environment of humidity and high salt spray for extended periods, making them prone to leakage.

[0003] Current technologies primarily rely on monitoring insulation resistance or using residual current devices (RCDs) to prevent leakage. For example, monitoring the insulation resistance to ground of a high-voltage system triggers an alarm or cuts off the power when the resistance falls below a set threshold; or the RCD detects the current difference (residual current) between the live and neutral wires for protection. However, these conventional solutions reveal numerous drawbacks under the unique operating conditions of ships. For instance, traditional RCDs are prone to malfunctions in high-humidity and high-salt-spray environments due to increased system-to-ground capacitance current and measurement noise interference, or they may experience delayed responses when actual action is needed. Furthermore, the lack of effective, real-time monitoring of the hidden fault of aging insulation materials prevents predictive maintenance. Moreover, the reliability and stability of existing protection devices significantly decrease under complex conditions such as extreme temperatures and severe vibrations. Summary of the Invention

[0004] The purpose of this invention is to provide a high-voltage leakage protection system for marine propulsion systems, in order to solve the problems of insufficient leakage detection accuracy, poor protection reliability, and lack of effective insulation aging monitoring in the complex marine environment mentioned in the background art.

[0005] To achieve the above objectives, the present invention aims to provide a high-voltage leakage protection system for marine propulsion systems, the leakage protection system comprising a dynamic leakage detection module, a signal processing and control module, a rapid power-off execution module, an environmental adaptability module, and an alarm module; The dynamic leakage current detection module is used to collect the current difference signal, insulation resistance signal and auxiliary signal of the leakage current protection system in real time. The signal processing and control module is connected to the dynamic leakage current detection module and is used to run the dynamic leakage current detection algorithm, analyze the current difference signal and insulation resistance signal, and generate protection commands based on the adaptive threshold adjustment mechanism. The rapid power-off execution module is connected to the signal processing and control module and is used to respond to the protection command and cut off the power supply of the leakage protection system. The environmental adaptability module includes a humidity compensation unit and a temperature and humidity monitoring unit connected to the rapid power-off execution module; The alarm module is used to perform corresponding alarm operations according to the instructions sent by the signal processing and control module; The dynamic leakage current detection algorithm utilizes both current difference detection and insulation resistance monitoring for dual-channel monitoring, and dynamically calculates the current difference alarm threshold and insulation resistance alarm threshold based on the real-time operating status of the leakage current protection system.

[0006] As a further improvement to this technical solution, the specific operation steps for the dynamic leakage current detection module to acquire the current difference signal of the leakage current protection system in real time are as follows: Step 1, Signal Sensing: Using a zero-sequence current transformer, the three-phase four-wire of the leakage protection system is... Simultaneously passing through its magnetic core to induce three-phase four-wire Instantaneous current value ; Step 2, Vector Summation: Based on Kirchhoff's Current Law, according to the formula... The instantaneous residual current was calculated. ; Step 3, Signal Conditioning: Conditioning the instantaneous residual current... Signal conditioning is performed, including filtering to remove high-frequency noise, amplification to a suitable processing level, and calculation of the residual current RMS value at power frequency. ; Step 4, Output: The final output is the effective value of the residual current at power frequency. That's all.

[0007] As a further improvement to this technical solution, the specific operation steps for the dynamic leakage current detection module to collect the insulation resistance signal of the leakage current protection system in real time are as follows: Step 1, Test Signal Injection: A known and safe test signal is injected between the leakage current protection system and ground using an insulation monitoring instrument. A constant low-voltage DC current is injected using the DC injection method. Alternatively, a low-frequency AC test signal can be injected using the low-frequency AC injection method. ; Step 2, Voltage Response Measurement: Using a high-precision measurement circuit, the voltage response between the system and ground generated by the injected test signal is measured. The DC voltage to ground is measured using the DC injection method. Alternatively, the AC voltage response to ground can be measured using the low-frequency AC injection method. ; Step 3: Calculate the resistance value: Calculate the insulation resistance according to Ohm's law, using the DC injection method and the formula... The insulation resistance value was calculated. Alternatively, a low-frequency AC injection method can be used, first through the formula... The impedance magnitude was calculated. Because the frequency is extremely low, the capacitive reactance is very large, therefore the impedance amplitude is... It mainly reflects the resistive component, thus obtaining the insulation resistance value. ; Step 4: Output: Output the calculated insulation resistance value. The value is smoothed by filtering to eliminate instantaneous fluctuations, and the final output is the filtered insulation resistance value. .

[0008] As a further improvement to this technical solution, the auxiliary signal collected in real time by the dynamic leakage current detection module includes the total load current of the system. Ambient temperature Ambient humidity And the estimated value of the system's capacitance to ground The total load current of the system Data is obtained from environmental sensors to evaluate the performance of insulation materials and calculate adaptive thresholds, wherein the ambient temperature... and ambient humidity All data are acquired through environmental sensors and used to evaluate the performance of insulation materials and calculate adaptive thresholds. The system's estimated ground capacitance value... It is obtained by online or offline estimation using the transient process during system startup, impedance measurement at a specific frequency, or a model based on historical data / system topology.

[0009] As a further improvement to this technical solution, the signal processing and control module runs a dynamic leakage current detection algorithm to analyze the current difference signal and insulation resistance signal, and generates protection commands based on an adaptive threshold adjustment mechanism. The specific operation steps are as follows: Step 1: Signal Acquisition: Acquire the real-time current difference signal, insulation resistance signal, and auxiliary signal of the leakage protection system from the dynamic leakage current detection module; Step 2: Dynamic Adaptive Threshold Calculation: Based on the acquired current difference signal, insulation resistance signal, and auxiliary signal, calculate the current difference alarm threshold respectively. and insulation resistance alarm threshold ; Step 3: Multi-condition judgment and protection command generation: Judge and generate protection commands according to the priority order of emergency leakage judgment > insulation degradation judgment > environmental risk collaborative judgment; The conditions for emergency leakage current detection are as follows: > The protection command it generates is: immediately generate the highest priority emergency power-off command; The conditions for determining insulation degradation are: no emergency leakage current detection is triggered, and < The protection commands it generates are: generating an insulation fault alarm command, and can also generate a delayed power-off command in conjunction with it; The conditions for the environmental risk collaborative judgment are as follows: if the emergency leakage judgment and insulation degradation judgment are not triggered, the humidity compensation logic is invoked to determine the current humidity level, and the generated protection instruction is: if the humidity exceeds the warning threshold... But below the danger threshold If so, a compensation start command is generated, and the compensation effect is monitored. If it is within the maximum compensation time... If the indoor humidity does not drop to a safe level, a compensation failure warning will be generated. If the humidity reaches or exceeds the danger threshold, a warning will be issued. If so, a forced start compensation command will be generated immediately, and an emergency protection countdown will begin. If the humidity does not drop within this countdown period The following will generate a power-off command for environmental hazards; Step 4: Command Output and System Linkage: The emergency power-off and environmental hazard power-off commands generated in the above steps are sent to the rapid power-off execution module to cut off the power supply. The insulation fault alarm and compensation failure warning commands generated in the above steps are sent to the alarm module. The start compensation and forced start compensation commands generated in the above steps are sent to the humidity compensation unit in the environmental adaptability module.

[0010] As a further improvement to this technical solution, the current difference alarm threshold is calculated in the dynamic adaptive threshold calculation step. The specific operating steps are as follows: The basic current difference alarm threshold is set according to safety standards. ; According to the formula Calculate the ground capacitance current of the system ,in This is the proportionality coefficient. This represents the effective value of the system phase voltage. For the system frequency, according to the formula Calculate and measure the estimated values ​​of noise and harmonic effects. ,in These are empirical coefficients used to reflect load harmonics and noise levels. The effective value of the total load current of the system is determined by installing [something] on [something]. The effective values ​​of the three-phase currents are measured by the current transformers on each phase, and then calculated or synthesized from the effective values ​​of the three-phase currents. Then according to the formula Synthesized final current difference alarm threshold ,in and These are adjustable weighting coefficients.

[0011] As a further improvement to this technical solution, the insulation resistance alarm threshold is calculated in the dynamic adaptive threshold calculation step. The specific operating steps are as follows: The basic insulation resistance alarm threshold is set according to the standard. ; According to the formula Temperature dynamic correction is performed to calculate the insulation resistance alarm threshold. ,in Represents an exponential function. For insulating materials, The current absolute temperature. For reference absolute temperature.

[0012] As a further improvement to this technical solution, the insulation layer of the wiring harness in the leakage protection system adopts a nanocomposite insulation material. The nanocomposite insulation material is a composite material with a polymer as the matrix and nano-carbon material as the filler. The nano-carbon material includes one or more of carbon nanotubes, graphene, graphene nanosheets or carbon nanofibers.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention employs a dual-channel monitoring mechanism combining current difference detection and insulation resistance monitoring, enabling the system to simultaneously capture rapid, sudden leakage faults and slow insulation degradation faults. Furthermore, by incorporating a dynamic adaptive threshold algorithm, the alarm threshold can be adjusted in real-time based on system load, ambient temperature and humidity, and ground capacitance, effectively overcoming the shortcomings of traditional fixed thresholds which are susceptible to interference in complex marine environments. This significantly reduces false alarm and missed alarm rates, achieving early warning and accurate judgment of concealed insulation faults.

[0014] 2. This invention optimizes the signal processing flow, thereby shortening the action time of the rapid power-off execution module, providing crucial rapid protection for personnel and equipment. At the same time, the integrated humidity compensation unit adopts hierarchical threshold and hysteresis control logic, prioritizing the activation of active dehumidification compensation when humidity exceeds the standard, and only executing power-off when compensation is ineffective or humidity reaches a dangerous critical value. This intelligent strategy of compensating first and then powering off effectively avoids unnecessary shutdowns caused by environmental fluctuations while ensuring safety, significantly improving the operating efficiency and availability of the ship's propulsion system. Attached Figure Description

[0015] Figure 1This is a block diagram illustrating the overall principle of the network security detection system of the present invention.

[0016] Figure 2 This is a circuit diagram of the fast power-off execution module of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In one specific embodiment, such as Figure 1 As shown, a high-voltage leakage current protection system for a marine propulsion system includes a dynamic leakage current detection module, a signal processing and control module, a rapid power-off execution module, an environmental adaptability module, and an alarm module. The system is connected and communicates via an internal data bus. Furthermore, the insulation layer of the wiring harness in the leakage current protection system uses a nanocomposite insulation material. This nanocomposite insulation material is a composite material with a polymer matrix and nano-carbon materials as fillers, wherein the nano-carbon materials include one or more of carbon nanotubes, graphene, graphene nanosheets, or carbon nanofibers.

[0019] The following provides a detailed introduction to the function and purpose of each module: The dynamic leakage current detection module is used to acquire the current difference signal, insulation resistance signal, and auxiliary signals of the leakage current protection system in real time. The dynamic leakage current detection algorithm uses both current difference detection and insulation resistance monitoring for dual-channel monitoring, and dynamically calculates the current difference alarm threshold and insulation resistance alarm threshold based on the real-time operating status of the leakage current protection system.

[0020] The specific operation steps for the dynamic leakage current detection module to acquire the current difference signal of the leakage current protection system in real time are as follows: Step 1, Signal Sensing: Using a zero-sequence current transformer, the three-phase four-wire of the leakage protection system is... Simultaneously passing through its magnetic core to induce three-phase four-wire Instantaneous current value ; Step 2, Vector Summation: Based on Kirchhoff's Current Law, according to the formula... The instantaneous residual current was calculated. ; Step 3, Signal Conditioning: Conditioning the instantaneous residual current... Signal conditioning is performed, including filtering to remove high-frequency noise, amplification to a suitable processing level, and calculation of the residual current RMS value at power frequency. ; Step 4, Output: The final output is the effective value of the residual current at power frequency. That's all.

[0021] The specific operation steps for the dynamic leakage current detection module to acquire the insulation resistance signal of the leakage current protection system in real time are as follows: Step 1, Test Signal Injection: A known and safe test signal is injected between the leakage current protection system and ground using an insulation monitoring instrument. A constant low-voltage DC current is injected using the DC injection method. Alternatively, a low-frequency AC test signal can be injected using the low-frequency AC injection method. ; Step 2, Voltage Response Measurement: Using a high-precision measurement circuit, the voltage response between the system and ground generated by the injected test signal is measured. The DC voltage to ground is measured using the DC injection method. Alternatively, the AC voltage response to ground can be measured using the low-frequency AC injection method. ; Step 3: Calculate the resistance value: Calculate the insulation resistance according to Ohm's law, using the DC injection method and the formula... The insulation resistance value was calculated. Alternatively, a low-frequency AC injection method can be used, first through the formula... The impedance magnitude was calculated. Because the frequency is extremely low, the capacitive reactance is very large, therefore the impedance amplitude is... It mainly reflects the resistive component, thus obtaining the insulation resistance value. ; Step 4: Output: Output the calculated insulation resistance value. The value is smoothed by filtering to eliminate instantaneous fluctuations, and the final output is the filtered insulation resistance value. .

[0022] The auxiliary signals collected in real time by the dynamic leakage current detection module include the total system load current. Ambient temperature Ambient humidity And the estimated value of the system's capacitance to ground The total load current of the system Data is obtained from environmental sensors to evaluate the performance of insulation materials and calculate adaptive thresholds, wherein the ambient temperature... and ambient humidity All data are acquired through environmental sensors and used to evaluate the performance of insulation materials and calculate adaptive thresholds. The system's estimated ground capacitance value... It is obtained by online or offline estimation using the transient process during system startup, impedance measurement at a specific frequency, or a model based on historical data / system topology.

[0023] The signal processing and control module is connected to the dynamic leakage current detection module. It runs the dynamic leakage current detection algorithm, analyzes the current difference signal and insulation resistance signal, and generates protection commands based on an adaptive threshold adjustment mechanism. Specifically: Step 1: Signal Acquisition: Acquire the real-time current difference signal, insulation resistance signal, and auxiliary signal of the leakage protection system from the dynamic leakage current detection module; Step 2: Dynamic Adaptive Threshold Calculation: Based on the acquired current difference signal, insulation resistance signal, and auxiliary signal, calculate the current difference alarm threshold respectively. and insulation resistance alarm threshold Specifically: Calculate the current difference alarm threshold The specific operating steps are as follows: The basic current difference alarm threshold is set according to safety standards. ; According to the formula Calculate the ground capacitance current of the system ,in This is the proportionality coefficient. This represents the effective value of the system phase voltage. For the system frequency, according to the formula Calculate and measure the estimated values ​​of noise and harmonic effects. ,in These are empirical coefficients used to reflect load harmonics and noise levels. The effective value of the total load current of the system is determined by installing [something] on [something]. The effective values ​​of the three-phase currents are measured by the current transformers on each phase, and then calculated or synthesized from the effective values ​​of the three-phase currents. Then according to the formula Synthesized final current difference alarm threshold ,in and These are adjustable weighting coefficients.

[0024] In a specific implementation case of this system, it was applied to a certain type of electric ship propulsion system with a rated voltage of 1500V and a system frequency of 50Hz. During actual commissioning, the adjustable weighting coefficients were determined through analysis of historical operating data. and The preferred range, for example, during the ship's startup phase, when the load current harmonics are relatively large, can be selected as... =1.2, =0.3; During the stable operation phase, it can be taken as 0.3. =0.8, =0.2. Those skilled in the art can adjust the coefficient value within the above range according to the specific system load characteristics and the degree of environmental interference to achieve the best protection effect.

[0025] Calculate the insulation resistance alarm threshold The specific operating steps are as follows: The basic insulation resistance alarm threshold is set according to the standard. ; According to the formula Temperature dynamic correction is performed to calculate the insulation resistance alarm threshold. ,in Represents an exponential function. For insulating materials, The current absolute temperature. For reference absolute temperature.

[0026] Step 3: Multi-condition judgment and protection command generation: Judge and generate protection commands according to the priority order of emergency leakage judgment > insulation degradation judgment > environmental risk collaborative judgment; The conditions for emergency leakage current detection are as follows: > The protection command it generates is: immediately generate the highest priority emergency power-off command; The conditions for determining insulation degradation are: no emergency leakage current detection is triggered, and < The protection commands it generates are: generating an insulation fault alarm command, and can also generate a delayed power-off command in conjunction with it; The conditions for the environmental risk collaborative judgment are as follows: if the emergency leakage judgment and insulation degradation judgment are not triggered, the humidity compensation logic is invoked to determine the current humidity level, and the generated protection instruction is: if the humidity exceeds the warning threshold... ( =85%) but below the danger threshold ( If the compensation rate is 95%, a compensation start command is generated, and the compensation effect is monitored. If the compensation time is within the maximum compensation period... ( If the humidity does not drop to a safe level within 10 minutes, a compensation failure warning will be generated. If the humidity reaches or exceeds the danger threshold, a warning will be issued. If so, a forced start compensation command will be generated immediately, and an emergency protection countdown will begin. If the humidity does not drop within this countdown period The following will generate a power-off command for environmental hazards; Step 4: Command Output and System Linkage: The emergency power-off and environmental hazard power-off commands generated in the above steps are sent to the rapid power-off execution module to cut off the power supply. The insulation fault alarm and compensation failure warning commands generated in the above steps are sent to the alarm module. The start compensation and forced start compensation commands generated in the above steps are sent to the humidity compensation unit in the environmental adaptability module.

[0027] The rapid power-off execution module is connected to the signal processing and control module to respond to protection commands and cut off the power supply to the leakage current protection system.

[0028] The environmental adaptability module includes a humidity compensation unit and a temperature and humidity monitoring unit connected to the rapid power-off execution module.

[0029] The alarm module is used to perform corresponding alarm operations based on the instructions sent by the signal processing and control module.

[0030] The system works as follows: 1. System initialization and self-test.

[0031] After the system is powered on, the signal processing and control module starts and runs the dynamic leakage current detection algorithm. The system first performs a self-test: checking if the communication between the zero-sequence current transformer and the insulation monitor in the dynamic leakage current detection module is normal; verifying the validity of the readings from the humidity sensor and humidity compensation unit in the environmental adaptability module; and sending a test command to the rapid power-off execution module to confirm the sensitivity of its tripping mechanism. After the self-test passes, the system enters real-time monitoring mode. The power-off principle of the rapid power-off execution module is as follows: Figure 2 The diagram illustrates how the system cuts off the main circuit power supply via a trip unit upon receiving an emergency power outage or environmental hazard power outage command. The rapid power outage execution module includes a trip unit, a drive circuit, and a power disconnection unit. When the signal processing and control module sends an emergency power outage or environmental hazard power outage command, the drive circuit responds immediately, controlling the trip unit to disconnect the main circuit power supply within milliseconds, achieving rapid protection for the system and personnel.

[0032] 2. Real-time acquisition and preprocessing of multi-source signals.

[0033] During system operation, the dynamic leakage current detection module continuously collects multiple signals.

[0034] Current difference signal acquisition: Real-time sensing of three-phase four-wire using zero-sequence current transformer instantaneous current The instantaneous residual current is obtained by vector summation. After filtering and amplification, the effective value of the signal at the power frequency is calculated. .

[0035] Insulation resistance signal acquisition: The insulation monitoring instrument uses the DC injection method to inject a known DC current between the system and ground. And measure the DC voltage to ground. Through formula The insulation resistance value was calculated, and then smoothed and filtered to obtain a stable value. .

[0036] Auxiliary signal acquisition: Acquire the total load current of the system. Ambient temperature Ambient humidity And call the pre-stored system-to-ground capacitance estimate. .

[0037] 3. Dynamic decision-making and protection instruction generation.

[0038] Based on the acquired signals, the signal processing and control module executes the following algorithm: Based on the acquired current difference signal, insulation resistance signal, and auxiliary signal, the current difference alarm threshold is calculated respectively. and insulation resistance alarm threshold Specifically: Calculate the current difference alarm threshold The specific operating steps are as follows: The basic current difference alarm threshold is set according to safety standards. ; According to the formula Calculate the ground capacitance current of the system ,in This is the proportionality coefficient. This represents the effective value of the system phase voltage. For the system frequency, according to the formula Calculate and measure the estimated values ​​of noise and harmonic effects. ,in These are empirical coefficients used to reflect load harmonics and noise levels. The effective value of the total load current of the system is determined by installing [something] on [something]. The effective values ​​of the three-phase currents are measured by the current transformers on each phase, and then calculated or synthesized from the effective values ​​of the three-phase currents. Then according to the formula Synthesized final current difference alarm threshold ,in and These are adjustable weighting coefficients.

[0039] Calculate the insulation resistance alarm threshold The specific operating steps are as follows: The basic insulation resistance alarm threshold is set according to the standard. ; According to the formula Temperature dynamic correction is performed to calculate the insulation resistance alarm threshold. ,in Represents an exponential function. For insulating materials, The current absolute temperature. For reference absolute temperature.

[0040] Multi-condition judgment and protection command generation: First Priority—Emergency Leakage Detection: System Comparison and ,like > If so, a high-priority emergency power-off command will be generated immediately.

[0041] Second priority—insulation degradation judgment: If the emergency judgment is not triggered, then compare... and ,like < If this is done, an insulation fault alarm command will be generated, and a delayed power-off command can be generated in conjunction with it.

[0042] Third priority—Environmental risk collaborative judgment: If the first two levels are not triggered, the humidity compensation logic is invoked. The system determines the current humidity level: If humidity exceeds the warning threshold But below the danger threshold If this is detected, a start compensation command is generated, activating the heater for active dehumidification. The system monitors the compensation effect; if it occurs within the maximum compensation time... If the internal humidity does not drop to a safe level, a compensation failure warning command will be generated.

[0043] If humidity reaches or exceeds the danger threshold If so, a forced start compensation command will be generated immediately, and an emergency protection countdown will begin. If the humidity does not drop within this countdown period The following will generate a power-off command for environmental hazards.

[0044] 4. Command issuance and system-wide execution.

[0045] The signal processing and control module distributes the generated instructions to each execution unit: Emergency power failure and environmental hazard power failure commands are sent to the rapid power failure execution module. Upon receiving the command, the module activates the trip unit within milliseconds to cut off the main circuit power supply.

[0046] Insulation fault alarm and compensation failure warning commands are sent to the alarm module, triggering the audible and visual alarm to remind the crew to take action.

[0047] The start compensation and forced start compensation commands are sent to the humidity compensation unit in the environmental adaptability module to control the heater to reduce the ambient humidity.

[0048] In addition, all instructions, key data and action events are recorded and can be uploaded to the remote monitoring center via the communication interface, facilitating fault diagnosis and historical data analysis.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-voltage leakage protection system for a marine propulsion system, characterized in that, The leakage current protection system includes a dynamic leakage current detection module, a signal processing and control module, a rapid power-off execution module, an environmental adaptability module, and an alarm module. The dynamic leakage current detection module is used to collect the current difference signal, insulation resistance signal and auxiliary signal of the leakage current protection system in real time. The signal processing and control module is connected to the dynamic leakage current detection module and is used to run the dynamic leakage current detection algorithm, analyze the current difference signal and insulation resistance signal, and generate protection commands based on the adaptive threshold adjustment mechanism. The rapid power-off execution module is connected to the signal processing and control module and is used to respond to the protection command and cut off the power supply of the leakage protection system. The environmental adaptability module includes a humidity compensation unit and a temperature and humidity monitoring unit connected to the rapid power-off execution module; The alarm module is used to perform corresponding alarm operations according to the instructions sent by the signal processing and control module; The dynamic leakage current detection algorithm utilizes both current difference detection and insulation resistance monitoring for dual-channel monitoring, and dynamically calculates the current difference alarm threshold and insulation resistance alarm threshold based on the real-time operating status of the leakage current protection system.

2. The high-voltage leakage protection system for marine propulsion systems according to claim 1, characterized in that, The auxiliary signals collected in real time by the dynamic leakage current detection module include at least one of the following: total system load current, ambient temperature, ambient humidity, and estimated system capacitance to ground.

3. The high-voltage leakage protection system for marine propulsion systems according to claim 1, characterized in that, The signal processing and control module runs a dynamic leakage current detection algorithm to analyze the current difference signal and insulation resistance signal, and generates protection commands based on an adaptive threshold adjustment mechanism. The specific operation steps are as follows: Step 1: Signal Acquisition: Acquire the real-time current difference signal, insulation resistance signal, and auxiliary signal of the leakage protection system from the dynamic leakage current detection module; Step 2, Dynamic Adaptive Threshold Calculation: Based on the acquired current difference signal, insulation resistance signal and auxiliary signal, calculate the current difference alarm threshold and insulation resistance alarm threshold respectively; Step 3: Multi-condition judgment and protection command generation: Judge and generate protection commands according to the priority order of emergency leakage judgment > insulation degradation judgment > environmental risk collaborative judgment.

4. The high-voltage leakage protection system for marine propulsion systems according to claim 3, characterized in that, The specific steps for calculating the current difference alarm threshold in the dynamic adaptive threshold calculation step are as follows: Set the basic current difference alarm threshold according to safety standards; The calculation system calculates the ground capacitance current, calculates and measures the estimated value of noise and harmonic effects, and obtains the effective value of the three-phase current by measuring the effective value of the three-phase current through current transformers installed on each phase, and then calculates or synthesizes the effective value of the three-phase current. The final current difference alarm threshold is synthesized.

5. The high-voltage leakage protection system for marine propulsion systems according to claim 3, characterized in that, The specific steps for calculating the insulation resistance alarm threshold in the dynamic adaptive threshold calculation step are as follows: The basic insulation resistance alarm threshold is set according to the standard. Temperature dynamic correction is performed to calculate the insulation resistance alarm threshold.

6. The high-voltage leakage protection system for marine propulsion systems according to claim 1, characterized in that, The insulation layer of the wiring harness in the leakage protection system is made of nanocomposite insulation material. The nanocomposite insulation material is a composite material with polymer as the matrix and nano-carbon material as the filler. The nano-carbon material includes one or more of carbon nanotubes, graphene, graphene nanosheets or carbon nanofibers.

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