Ship power grid transient electromagnetic interference grading evaluation method and system

Abstract

The invention discloses a ship power grid transient electromagnetic interference grading evaluation method and system, relates to the technical field of ship power grid safety evaluation, realizes scientific grading evaluation of ship power grid transient peak interference, and provides a reliable basis for stable operation and equipment protection of a ship power grid. Comprising the following steps: measuring a transient peak sensitive threshold value of equipment by adopting a peak signal transduction sensitivity test; performing classification and importance coefficient assignment on the equipment according to the importance degree of the equipment; and calculating a weighted average sensitive threshold value of load equipment at the rear end of the distribution box by adopting a weighted average method. At the output end of a power distribution box of a ship power grid cabin, a transient peak conducted emission detection device is used for monitoring and collecting power grid transient peak conducted emission data in real time, and a power grid transient peak interference measured value is recognized from the power grid transient peak conducted emission data. Comparing the power grid transient peak interference measured value with the weighted average sensitive threshold value, and calculating a difference value between the two values; and according to a difference value result, carrying out ship power grid transient peak interference grading evaluation.

Description

Technical Field

[0001] The present invention relates to the technical field of ship power grid security assessment, and in particular to a ship power grid transient electromagnetic interference hierarchical assessment method and system. Background Art

[0002] In shipboard power systems and power grids, transient spike interference is a significant factor affecting the normal operation of a ship's electronic and electrical systems and equipment. Transient spike interference can cause performance degradation or malfunction in critical systems and equipment such as sonar, navigation, and ship control, potentially leading to ship safety incidents. Shipboard power grids are complex, with specialized power generation and distribution systems. The types of load devices connected to the distribution boxes in each compartment are diverse. During ship operation, transient spike interference signals of varying intensities are frequently generated at both the source and load ends of the power grid, potentially causing equipment malfunction, performance degradation, or even damage, posing a serious threat to ship navigation safety and the stable operation of the power system.

[0003] At present, the detection of transient spike interference in ship power grids is mostly based on a single standard indicator test. There is a lack of comprehensive and systematic evaluation methods that can reflect the importance of diverse load equipment to ship safety and technical and tactical indicators. It is impossible to scientifically classify transient spike interference in ship power grids, and it is difficult to meet the needs of ships for accurate assessment and effective prevention and control of transient spike interference in power grids. Summary of the Invention

[0004] In view of this, the present invention provides a method and system for hierarchical assessment of transient electromagnetic interference in shipboard power grids, which realizes scientific hierarchical assessment of transient spike interference in shipboard power grids, provides a reliable basis for the stable operation of shipboard power grids and equipment protection, and ensures the safe operation of ships.

[0005] To achieve the above-mentioned purpose, the present invention provides a hierarchical evaluation method for transient electromagnetic interference of a shipboard power grid, the technical solution of which includes the following steps:

[0006] Step 1: Use the spike signal conduction sensitivity test to apply simulated transient spike interference signals of different intensities to the common grid load devices at the rear end of the distribution box in the ship's power grid compartment one by one to measure the transient spike sensitivity threshold of the equipment.

[0007] Step 2: Classify the equipment and assign importance coefficients based on their importance.

[0008] Combined with the transient spike sensitivity threshold and importance coefficient assignment of each device, the importance coefficient is used as the weight, and the weighted average method is adopted to calculate the weighted average sensitivity threshold of the load devices behind the distribution box.

[0009] Step 3: At the output end of the distribution box in the ship's power grid compartment, a transient spike conducted emission detection device is used to monitor and collect power grid transient spike conducted emission data in real time, from which the power grid transient spike interference measurement value is identified.

[0010] Step 4: Compare the measured value of the grid transient spike interference with the weighted average sensitivity threshold and calculate the difference between the two; based on the difference result, conduct a graded evaluation of the shipboard grid transient spike interference.

[0011] Furthermore, step 1 is specifically as follows: for the common grid load equipment at the rear end of the distribution box in the ship's power grid compartment, a transient spike signal is injected, the transient spike signal pulse width is 10us±20%, and the transient spike signal amplitude V P The voltage shall be increased in sequence from 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V, 800V, 850V and 900V. The injection time of transient spike signal for each amplitude shall be no less than 10min. At the same time, the phase of transient spike signal shall be adjusted. When abnormal performance or failure occurs, the interference signal threshold level, i.e., the sensitive threshold of the equipment, shall be recorded. For equipment that does not exhibit electromagnetic interference during the test, the sensitive threshold shall be recorded as the maximum value of 900V.

[0012] Furthermore, in step 2, the equipment is classified and the importance coefficient is assigned according to its importance. Specifically, the equipment is divided into Class I to Class III equipment according to its importance; the importance coefficient assignment range is set to 1-10; Class I equipment is the most important equipment type on the ship. After being subjected to transient spike electromagnetic interference, Class I equipment will cause physical damage to the subsystem or equipment, affecting the performance and safety of the entire ship; the importance coefficient of Class I equipment is set to w i The value range is 1-3; Class II equipment refers to: after being subjected to transient peak electromagnetic interference, the subsystem or equipment performance is reduced or malfunctions occur, which only makes the system unable to complete some functions without affecting the safety of the system and personnel; the importance coefficient of Class II equipment is w i The value range is set to 4-6; Class III equipment refers to: after being subjected to transient peak electromagnetic interference, this type of subsystem and equipment will only experience reduced working performance without failure; or even if a failure occurs, it will recover to working state within a certain period of time after repair, and will not cause the system equipment to lose function; the importance coefficient of Class III equipment is w i The value range is set to 7-10.

[0013] Furthermore, in step 2, the weighted average sensitivity threshold of the main load equipment at the back end of the distribution box is calculated as : ; Among them, S i is the sensitivity threshold of the i-th load device, w iis the importance coefficient of the i-th load device.

[0014] Furthermore, in step 3, at the output end of the distribution box in the ship's power grid compartment, a transient spike conducted emission detection device is used to monitor and collect power grid transient spike conducted emission data in real time, wherein the monitoring and collection process is specifically as follows:

[0015] The time for monitoring and collecting emission data shall not be less than one sea voyage of the ship.

[0016] During the monitoring and collection process, low-frequency transmitting equipment such as sonar on the ship should transmit at full power for no less than 2 times; radio frequency transmitting equipment should transmit at rated power for no less than 2 times, and the transmitting frequency should be 2 frequency points within their respective working frequency bands.

[0017] The microwave transmitting equipment shall transmit at full power for no less than 2 times.

[0018] High-power equipment whose power exceeds the set value shall be started, operated, stopped or switched to the operating state at least twice; high-power equipment includes high-pressure air compressors, bilge pumps, hydraulic pumps for the entire ship, and propellers.

[0019] Furthermore, in step 3, the grid transient spike conduction emission data is monitored and collected, and the grid transient spike interference measurement value is identified therefrom, specifically in the following manner:

[0020] For the transient spike interference signal collected by monitoring, according to the parameters of the transient spike interference signal including intensity, pulse width, and occurrence frequency, the peak detection and statistical analysis method is used to extract the maximum value from the time-varying signal sequence, and the transient spike interference peak value V is identified by combining the spectrum characteristics and energy distribution of the transient spike signal. PEAK .

[0021] The measured value of the transient peak interference of the power grid is:

[0022] .

[0023] Furthermore, step 4: compare the measured value of the power grid transient spike interference with the weighted average sensitivity threshold and calculate the difference between the two; based on the difference result, carry out the ship power grid transient spike interference classification evaluation, specifically:

[0024] Comparison of the power grid transient peak interference measurement value dBV and the weighted average sensitivity threshold , calculate the difference between the two =dBV- According to the difference results, the ship power grid transient peak interference classification evaluation is carried out as follows. <-30dB: No risk level; all load devices in the power distribution box in the power grid compartment can work normally and compatibly, and generally no electromagnetic interference occurs. When in the range of -30dB~-6dB: low risk level; the electromagnetic interference risk on board is controllable. In the range of -6dB~0dB: medium risk level; there is a risk of transient spike electromagnetic interference on board; >0dB range: high risk level; electromagnetic interference is potential or has occurred on board.

[0025] Another aspect of the embodiments of the present invention further provides a system for grading and evaluating transient electromagnetic interference in a shipboard power grid, including the following modules:

[0026] The sensitivity threshold determination module is used to conduct a spike signal conduction sensitivity test, applying simulated transient spike interference signals of different intensities to the common load equipment at the rear end of the distribution box in the ship's power grid compartment one by one, and measuring the transient spike sensitivity threshold of the equipment; specifically: for the common load equipment at the rear end of the distribution box in the ship's power grid compartment, inject a transient spike signal with a transient spike signal pulse width of 10us±20% and a transient spike signal amplitude V P The voltage shall be increased in sequence from 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V, 800V, 850V and 900V. The injection time of transient spike signal for each amplitude shall be no less than 10min. At the same time, the phase of transient spike signal shall be adjusted. When abnormal performance or failure occurs, the interference signal threshold level, i.e., the sensitive threshold of the equipment, shall be recorded. For equipment that does not exhibit electromagnetic interference during the test, the sensitive threshold shall be recorded as the maximum value of 900V.

[0027] The weighted average sensitivity threshold calculation module is used to classify devices and assign importance coefficients according to their importance. It combines the transient spike sensitivity threshold and importance coefficient values ​​of each device obtained in the sensitivity threshold determination module, uses the importance coefficient as the weight, and uses the weighted average method to calculate the weighted average sensitivity threshold of the load devices at the back end of the distribution box. Specifically,

[0028]

[0029] in, is the calculated weighted average sensitivity threshold of the main load equipment behind the distribution box, S i is the sensitivity threshold of the i-th load device, w i is the importance coefficient of the i-th load device; the devices are divided into Class I to Class III devices according to their importance.

[0030] The importance coefficient assignment range is set to 1-10.

[0031] Class I equipment is the most important equipment on board. When Class I equipment is subjected to transient spike electromagnetic interference, it will cause physical damage to the subsystem or equipment, affecting the performance and safety of the entire ship. The importance coefficient of Class I equipment is set as w i The value range is 1-3.

[0032] Class II equipment refers to equipment that, after being subjected to transient spike electromagnetic interference, causes subsystem or equipment performance degradation or failure, only making the system unable to complete some functions without affecting the safety of the system and personnel; the importance coefficient of Class II equipment is w i The value range is set to 4-6.

[0033] Class III equipment refers to: after being subjected to transient peak electromagnetic interference, the subsystems and equipment of this type will only experience reduced working performance without failure; or even if a failure occurs, it will recover to working state within a certain period of time after repair, and will not cause the system equipment to lose function; the importance coefficient of Class III equipment is w i The value range is set to 7-10.

[0034] The grid transient spike interference measurement value identification module is used to apply the transient spike conducted emission detection device at the output end of the ship's grid compartment distribution box to monitor and collect grid transient spike conducted emission data in real time, and identify the grid transient spike interference measurement value therefrom.

[0035] The evaluation module is used to compare the measured value of the power grid transient spike interference with the weighted average sensitivity threshold and calculate the difference between the two; based on the difference result, a graded evaluation of the ship power grid transient spike interference is carried out.

[0036] Furthermore, in the grid transient spike interference measurement value identification module, at the output end of the distribution box in the ship's grid compartment, a transient spike conducted emission detection device is used to monitor and collect grid transient spike conducted emission data in real time, wherein the monitoring and collection process is specifically as follows:

[0037] The time for monitoring and collecting emission data shall not be less than one sea voyage of the ship.

[0038] During the monitoring and collection process, low-frequency transmitting equipment such as sonar on the ship should transmit at full power for no less than 2 times; radio frequency transmitting equipment should transmit at rated power for no less than 2 times, and the transmitting frequency should be 2 frequency points within their respective working frequency bands.

[0039] The microwave transmitting equipment shall transmit at full power for no less than 2 times.

[0040] High-power equipment whose power exceeds the set value shall be started, operated, stopped or switched to the operating state at least twice; high-power equipment includes high-pressure air compressors, bilge pumps, hydraulic pumps for the entire ship, and propellers.

[0041] In the grid transient spike interference measurement value identification module, the grid transient spike conduction emission data is monitored and collected, and the grid transient spike interference measurement value is identified from it. The specific method is as follows:

[0042] For the transient spike interference signal collected by monitoring, according to the parameters of the transient spike interference signal including intensity, pulse width, and occurrence frequency, the peak detection and statistical analysis method is used to extract the maximum value from the time-varying signal sequence, and the transient spike interference peak value V is identified by combining the spectrum characteristics and energy distribution of the transient spike signal. PEAK .

[0043] The measured value of the transient peak interference of the power grid is: .

[0044] Furthermore, the evaluation module specifically compares the grid transient spike interference measurement value dBV with the weighted average sensitivity threshold , calculate the difference between the two =dBV- , according to the difference results, the ship power grid transient peak interference classification evaluation is carried out as follows; < -30dB: No risk level; all load devices in the power distribution box in the power grid compartment can work normally and compatibly, and generally no electromagnetic interference occurs; In the range of -30dB to -6dB: low risk level; electromagnetic interference risk on board is controllable; In the range of -6dB~0dB: medium risk level; there is a risk of transient spike electromagnetic interference on board; >0dB range: high risk level; electromagnetic interference is potential or has occurred on board.

[0045] Beneficial effects:

[0046] 1) The present invention provides a method for grading and evaluating transient electromagnetic interference in ship power grids. This method implements scientific grading and evaluation of transient spike interference in ship power grids through real-time online detection and comprehensive analysis of the anti-interference capability and sensitivity threshold of load equipment at the rear end of the ship's cabin distribution box, as well as the transient spike interference in the ship power grid. The grading and evaluation of transient spike interference in ship power grids and different risk levels can intuitively reflect the degree of impact of transient spike interference in ship power grids on equipment, providing a decision-making basis for safe ship operation and power system maintenance and management, thereby ensuring safe ship operation.

[0047] 2) The present invention provides a hierarchical assessment method for transient electromagnetic interference in shipboard power grids. This method comprehensively considers the anti-interference capability, sensitivity threshold, and importance of different load devices in the shipboard power grid. Through a scientific calculation method, the weighted average sensitivity threshold of the load devices in the cabin distribution box area of ​​the power grid is obtained. The evaluation results can better reflect the tolerance of the load devices on the ship to transient interference in the power grid. Compared with single indicator detection, the evaluation results are more comprehensive and accurate.

[0048] 3) The present invention provides a hierarchical assessment method for transient electromagnetic interference in shipboard power grids. By measuring the transient peak interference signal of the power grid and comparing it with the average sensitivity, this method achieves a hierarchical assessment of transient peak interference in shipboard power grids. This method can intuitively provide shipboard operators with information on the risk level of transient peak interference in the power grid, facilitating the timely implementation of targeted protection and optimization measures to ensure the stable operation of the shipboard power grid and the safety of equipment.

[0049] 4) The evaluation method involved in the present invention has strong practicality and operability, and is suitable for transient spike evaluation of ship power grids of different types and sizes, which helps to improve the reliability and intelligent management level of ship power grid systems.

[0050] 5) The present invention provides a ship power grid transient electromagnetic interference grading assessment system, which can be used to execute the above-mentioned ship power grid transient spike interference grading assessment method. The system implements each function in the assessment method in a modular manner. Through each module, the anti-interference ability, sensitivity threshold and ship power grid transient spike interference of the load equipment at the rear end of the ship cabin distribution box are detected and comprehensively analyzed in real time, thereby realizing a scientific grading assessment of the ship power grid transient spike interference. Through the ship power grid transient spike interference grading assessment and different risk levels, the impact of the ship power grid transient spike interference on the equipment can be intuitively reflected, providing a decision-making basis for the safe operation of the ship and the maintenance and management of the power system, thereby ensuring the safe operation of the ship. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A flow chart of a method for hierarchical assessment of transient electromagnetic interference in a shipboard power grid provided in Example 1 of the present invention;

[0052] Figure 2 This is a test configuration diagram for a spike signal conduction sensitivity test in Example 1 of the present invention;

[0053] Figure 3 Injecting a transient spike signal into the spike signal conduction sensitivity in embodiment 1 of the present invention;

[0054] Figure 4 This is a configuration diagram for the grid transient spike conducted emission test in Example 1 of the present invention;

[0055] Figure 5This is a block diagram of a ship power grid transient electromagnetic interference classification assessment system provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0056] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0057] Example 1:

[0058] This embodiment provides a method for evaluating transient electromagnetic interference of a ship power grid by levels. Figure 1 As shown, the method includes the following steps:

[0059] Step 1: Determine the equipment transient spike sensitivity threshold through the load equipment spike signal conduction sensitivity test.

[0060] In an embodiment of the present invention, with reference to the spike signal conduction sensitivity test (CS06) method in HJB34A-2007 "Electromagnetic Compatibility Requirements for Ships", simulated transient spike interference signals of varying intensities are applied to each of the common load devices at the rear end of the distribution box in the ship's power grid compartment. Parameters such as the interference signal threshold level when each device exhibits performance anomalies or failures are recorded to determine the device's sensitivity threshold, which can reflect the device's sensitivity to transient spike interference of varying intensities.

[0061] The spike signal conduction sensitivity test configuration diagram is as follows Figure 2 .

[0062] In this embodiment, the transient spike signal is injected as Figure 3 The pulse width of the transient spike signal is 10us±20%. The amplitude of the transient spike signal is V P Conduct the test at increasing voltages of 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V, 800V, 850V, and 900V, respectively. Each transient spike signal should be injected for at least 10 minutes, and the phase of the transient spike signal should be adjusted. In the event of performance anomalies or malfunctions, record the interference signal threshold level, i.e., the device's sensitivity threshold. For devices that exhibit no electromagnetic interference during the test, the sensitivity threshold is recorded as the maximum value of 900V.

[0063] Step 2: Classify the equipment and assign importance coefficients based on the importance of the equipment, that is, the degree of consequences or damage that may be caused to the ship platform after the transient peak electromagnetic interference occurs.

[0064] The transient spike sensitivity threshold of each device measured in step 1 does not mean that electromagnetic interference will definitely occur when the equipment is loaded on board and is exposed to a transient spike signal that reaches or approaches the sensitivity threshold. It only indicates that the probability of electromagnetic interference is high. Conversely, the smaller the transient spike interference signal is than the sensitivity threshold, the lower the probability of electromagnetic interference.

[0065] Different devices are assigned importance coefficients to reflect their importance, i.e., the potential consequences or damage to the ship platform caused by transient spike electromagnetic interference. For more important devices, such as the Class I devices described below, smaller importance coefficients are assigned, using the importance coefficients as weights, thereby reducing the average sensitivity calculated after weighted assignment.

[0066] In this embodiment, the importance coefficient assignment range is set to 1-10, and the higher the importance, the smaller the assigned value.

[0067] Class I equipment: The most important equipment on a ship. After being subjected to transient spike electromagnetic interference, it may cause physical damage to subsystems or equipment, and even affect the performance and safety of the entire ship. Importance coefficient w i The value range is set to 1-3.

[0068] Class II equipment: Equipment of high importance on ships. After being subjected to transient spike electromagnetic interference, it may cause the subsystem or equipment to have reduced performance or malfunction. It only makes the system unable to complete some functions, but does not affect the safety of the system and personnel. Importance coefficient w i The value range is set to 4-6.

[0069] Category III equipment: Equipment of average importance on ships. After being subjected to transient spike electromagnetic interference, the subsystems and equipment of this category will only experience reduced performance without causing any failure; or even if a failure occurs, it can be quickly restored to working condition by crew repairs, and will not cause the system equipment to lose function. Importance coefficient w i The value range can be set to 7-10.

[0070] In this embodiment, the weighted average sensitivity threshold of the load devices at the rear end of the distribution box is calculated by combining the transient spike sensitivity threshold and importance value of each device obtained in step 1, specifically:

[0071] The calculated weighted average sensitivity threshold of the main load equipment behind the distribution box is :

[0072]

[0073] Among them, S i is the sensitivity threshold of the i-th load device, w i is the importance coefficient of the i-th load device.

[0074] Step 3: At the output end of the distribution box in the ship's power grid compartment, a transient spike conducted emission detection device is used to monitor and collect power grid transient spike conducted emission data in real time.

[0075] The grid transient spike conducted emission test configuration diagram is as follows: Figure 4 .

[0076] The monitoring and data collection time should be no less than one sea voyage of the ship. During the monitoring and data collection process, low-frequency transmitting equipment such as sonar on board the ship should transmit at full power at least twice; shortwave communication equipment, satellite communication equipment and other radio frequency transmitting equipment should transmit at rated power at least twice (the transmitting frequency should be the higher and lower frequencies within their respective operating frequency bands); microwave transmitting equipment such as radar should transmit at full power at least twice; and high-power equipment such as high-pressure air compressors, bilge pumps, hydraulic pumps throughout the ship, and propellers should be started, operated, stopped, or switched between operating states at least twice.

[0077] For the transient spike interference signal collected by monitoring, according to the intensity, pulse width, occurrence frequency and other parameters of the transient spike interference signal, the peak detection and statistical analysis method is used to extract the maximum value from the time-varying signal sequence, and the transient spike interference peak value V is identified by combining the spectrum characteristics and energy distribution of the transient spike signal. PEAK .

[0078] The measured value of the transient peak interference of the power grid is:

[0079] .

[0080] Step 4: Grading evaluation of shipboard power grid transient spike interference.

[0081] Comparison of the power grid transient peak interference measurement value dBV and the weighted average sensitivity threshold , calculate the difference between the two =dBV- , according to the difference results, the ship power grid transient peak interference classification evaluation is carried out as follows; < -30dB: No risk level; all load devices in the power distribution box in the power grid compartment can work normally and compatibly, and generally no electromagnetic interference occurs. In the range of -30dB~-6dB: low risk level; the electromagnetic interference risk on board is controllable, and close attention should be paid to the sensitive thresholds of each device and the transient spike test results of the power grid. In the range of -6dB~0dB: medium risk level; there may be transient spike electromagnetic interference risk hazards on board, and it is necessary to actively reserve electromagnetic interference protection measures to reduce the risk of electromagnetic interference. >0dB: High risk level; electromagnetic interference is potential or has occurred on board, and it is necessary to investigate and rectify weak links in electromagnetic compatibility and take effective electromagnetic interference protection and control measures until the transient peak interference assessment is downgraded.

[0082] Through the graded evaluation of ship power grid transient spike interference and different risk levels, the impact of ship power grid transient spike interference on equipment can be intuitively reflected, providing a decision-making basis for ship safety operation and power system maintenance and management.

[0083] Example 2:

[0084] In this embodiment, a method for hierarchical assessment of transient electromagnetic interference in a shipboard power grid is implemented by the following steps:

[0085] Step 1: During a ship's voyage, conduct a transient spike interference sensitivity test on n load devices located at the rear of the cockpit power distribution box to determine their transient spike sensitivity thresholds. Using dedicated electromagnetic compatibility test equipment, apply a transient spike interference signal with a 10µs pulse width and a 400V to 900V increment in accordance with relevant standards to each device. Record the interference signal threshold level parameters when each device experiences abnormalities such as performance degradation and malfunction to determine the device sensitivity threshold. For example, when a transient spike interference signal with a strength of 500V and a duration of 10us is injected into a sonar device, the sonar display spectrum appears black and flickering, so the sonar sensitivity threshold S1 is 500V. When a transient spike interference signal with a strength of 600V and a duration of 10us is injected into an electronic chart system, garbled characters appear on the electronic chart display, so the sensitivity threshold S2 is 600V. When a transient spike interference signal with a strength of 350V and a duration of 10us is injected into a lighting device, the lighting device exhibits a noticeable brightness change, so the sensitivity threshold S3 is 350V. When a transient spike interference signal with a pulse width of 10us is injected into a steering device, no sensitivity occurs, so the sensitivity threshold is set to S4 = 900V.

[0086] Step 2: Assign importance coefficients to the n devices in the cockpit based on their functions and importance in ship operation. Assign the importance coefficient of the sonar to w1 = 2, the importance coefficient of the electronic chart system to w2 = 6, the importance coefficient of the lighting to w3 = 10, and the importance coefficient of the steering system to w4 = 1, etc.

[0087] Calculate the weighted average sensitivity threshold of the main load equipment at the rear end of the cockpit power distribution box, see Table 1.

[0088] Table 1

[0089]

[0090] Step 3: During the voyage, a high-precision transient spike interference signal detection device is installed at the output end of the cockpit distribution box. The device is continuously operated for 120 hours to collect transient spike interference signals and perform spectrum analysis, intensity calculation and other processing on the signals. The peak value of transient spike interference of the power grid V PEAK =100V.

[0091] Grid transient spike interference measurement value = 40dB.

[0092] Step 4: Compare the measured values ​​of grid transient spike interference and weighted average sensitivity threshold , calculate the difference Δ = dBV- = -13.5. According to the classification rules, the cockpit power grid transient spike interference during this period is determined to be at a low risk level. The electromagnetic interference risk on board is controllable. During navigation, close attention should be paid to the sensitivity thresholds of various devices and the transient spike test results of the power grid.

[0093] Example 3:

[0094] In order to realize the ship power grid transient electromagnetic interference hierarchical assessment method as proposed in the embodiment, this embodiment also provides a ship power grid transient electromagnetic interference hierarchical assessment system, which is composed of the following components: Figure 5 As shown, it includes the following modules:

[0095] The sensitivity threshold determination module is used to apply simulated transient spike interference signals of varying intensities to the common network load devices at the rear end of the distribution box in the ship's power grid compartment, using a spike signal conduction sensitivity test, to measure the transient spike sensitivity threshold of the devices. In this embodiment, the sensitivity threshold determination module specifically performs the following steps:

[0096] For the common grid load equipment at the rear end of the distribution box in the ship's power grid compartment, a transient spike signal is injected. The transient spike signal pulse width is 10us±20%, and the transient spike signal amplitude is V P The voltage shall be increased in sequence from 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V, 800V, 850V and 900V. The injection time of transient spike signal for each amplitude shall be no less than 10min. At the same time, the phase of transient spike signal shall be adjusted. When abnormal performance or failure occurs, the interference signal threshold level, i.e., the sensitive threshold of the equipment, shall be recorded. For equipment that does not exhibit electromagnetic interference during the test, the sensitive threshold shall be recorded as the maximum value of 900V.

[0097] The weighted average sensitivity threshold calculation module is used to classify devices and assign importance coefficients according to their importance. Combined with the transient spike sensitivity threshold and importance coefficient assignment of each device obtained in step 1, the weighted average sensitivity threshold of the load devices at the back end of the distribution box is calculated using a weighted average method. In this embodiment, the weighted average sensitivity threshold calculation module classifies devices and assigns importance coefficients according to their importance, specifically as follows:

[0098] Equipment is divided into Class I to Class III according to its importance;

[0099] The importance coefficient assignment range is set to 1-10;

[0100] Class I equipment is the most important equipment on board. When Class I equipment is subjected to transient spike electromagnetic interference, it will cause physical damage to the subsystem or equipment, affecting the performance and safety of the entire ship. The importance coefficient of Class I equipment is set as w i The value range is 1-3.

[0101] Class II equipment refers to equipment that, after being subjected to transient spike electromagnetic interference, causes subsystem or equipment performance degradation or failure, only making the system unable to complete some functions without affecting the safety of the system and personnel; the importance coefficient of Class II equipment is w i The value range is set to 4-6.

[0102] Class III equipment refers to: after being subjected to transient peak electromagnetic interference, the subsystems and equipment of this type will only experience reduced working performance without failure; or even if a failure occurs, it will recover to working state within a certain period of time after repair, and will not cause the system equipment to lose function; the importance coefficient of Class III equipment is w i The value range is set to 7-10.

[0103] The calculated weighted average sensitivity threshold of the main load equipment behind the distribution box is :

[0104]

[0105] Among them, S i is the sensitivity threshold of the i-th load device, w i is the importance coefficient of the i-th load device.

[0106] The grid transient spike interference measurement value identification module is used to apply the transient spike conducted emission detection device at the output end of the ship's grid compartment distribution box to monitor and collect grid transient spike conducted emission data in real time, and identify the grid transient spike interference measurement value therefrom.

[0107] In this embodiment, the time for monitoring and collecting emission data is not less than one sea voyage of the ship;

[0108] During the monitoring and collection process, low-frequency transmitting equipment such as sonar on board the ship should transmit at full power for no less than 2 times; radio frequency transmitting equipment should transmit at rated power for no less than 2 times, with the transmitting frequency taking 2 frequency points within their respective operating frequency bands;

[0109] The microwave transmitting equipment shall be transmitted at full power for no less than 2 times;

[0110] High-power equipment with a power exceeding the set value must be started, operated, and stopped (or switched to a different operating state) at least twice; high-power equipment includes high-pressure air compressors, bilge pumps, hydraulic pumps throughout the ship, and propellers;

[0111] For the transient spike interference signal collected by monitoring, according to the parameters of the transient spike interference signal including intensity, pulse width, and occurrence frequency, the peak detection and statistical analysis method is used to extract the maximum value from the time-varying signal sequence, and the transient spike interference peak value V is identified by combining the spectrum characteristics and energy distribution of the transient spike signal. PEAK ;

[0112] The measured value of the transient peak interference of the power grid is:

[0113] .

[0114] The evaluation module is used to compare the measured value of the power grid transient spike interference with the weighted average sensitivity threshold and calculate the difference between the two; based on the difference result, a graded evaluation of the ship power grid transient spike interference is carried out; in this embodiment, the evaluation module is specifically:

[0115] Comparison of the power grid transient peak interference measurement value dBV and the weighted average sensitivity threshold , calculate the difference between the two =dBV- According to the difference results, the ship power grid transient peak interference classification evaluation is carried out as follows. < -30dB: No risk level; all load devices in the power distribution box in the power grid compartment can work normally and compatibly, and generally no electromagnetic interference occurs. When in the range of -30dB~-6dB: low risk level; the electromagnetic interference risk on board is controllable. When in the range of -6dB~0dB: medium risk level; there is a risk of transient spike electromagnetic interference on board. >0dB range: high risk level; electromagnetic interference is potential or has occurred on board.

[0116] This embodiment provides a shipboard power grid transient electromagnetic interference classification assessment system, wherein each module can be implemented not only by a data processing program but also by hardware, for example, by logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. Therefore, such hardware capable of implementing the present method also constitutes the present application.

[0117] The flowcharts and block diagrams in the accompanying drawings of the present application show the possible implementation architecture, functions and operations of the systems, methods and computer program products according to the various embodiments disclosed in the present application. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of code, and the above-mentioned module, program segment, or a part of code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in the order of the standards in different figures. For example, the boxes represented by two connections can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of the boxes in the block diagram or flowchart, can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0118] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for hierarchical assessment of transient electromagnetic interference in shipboard power grids, characterized in that: The steps include: Step 1: Using the spike signal conduction sensitivity test, simulated transient spike interference signals of varying intensities are applied to each of the common load devices at the rear end of the distribution box in the ship's power grid compartment to measure the transient spike sensitivity threshold of the devices. Step 2: Classify the equipment and assign importance coefficients according to their importance; Combined with the transient spike sensitivity threshold and importance coefficient of each device, the importance coefficient is used as the weight, and the weighted average sensitivity threshold of the load devices behind the distribution box is calculated using the weighted average method; Step 3: At the output end of the distribution box in the ship's power grid compartment, a transient spike conducted emission detection device is used to monitor and collect power grid transient spike conducted emission data in real time, from which the power grid transient spike interference measurement value is identified; Step 4: Compare the measured value of the grid transient spike interference with the weighted average sensitivity threshold and calculate the difference between the two; based on the difference result, conduct a graded evaluation of the shipboard grid transient spike interference.

2. A method for hierarchical assessment of transient electromagnetic interference in a shipboard power grid according to claim 1, characterized in that: The step 1 is specifically as follows: For the common grid load equipment at the rear end of the distribution box in the ship's power grid compartment, a transient spike signal is injected. The transient spike signal pulse width is 10us±20%, and the transient spike signal amplitude V P Conduct the test at increasing voltages of 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V, 800V, 850V, and 900V in sequence. The injection time of each amplitude transient spike signal shall not be less than 10 minutes. At the same time, adjust the phase of the transient spike signal. When performance abnormalities or faults occur, record the interference signal threshold level, i.e., the sensitivity threshold of the equipment. During the test, no electromagnetic interference occurred in the equipment, and the sensitivity threshold was recorded as the maximum value of 900V.

3. The method for hierarchical evaluation of transient electromagnetic interference in a shipboard power grid according to claim 1, wherein: In step 2, the equipment is classified and assigned importance coefficients according to their importance, specifically: Equipment is divided into Class I to Class III according to its importance; The importance coefficient assignment range is set to 1-10; Class I equipment is the most important equipment on board. When Class I equipment is subjected to transient spike electromagnetic interference, it may cause physical damage to the subsystem or equipment, affecting the performance and safety of the entire ship. Set the importance factor w for Class I equipment i The value range is 1-3; The Class II equipment refers to equipment that, after being subjected to transient spike electromagnetic interference, causes the subsystem or equipment to degrade in performance or malfunction, only making the system unable to complete some functions without affecting the safety of the system and personnel; the importance coefficient of Class II equipment is w i The value range is set to 4-6; Class III equipment refers to: after being subjected to transient peak electromagnetic interference, the subsystems and equipment of this type will only experience reduced working performance without failure; or even if a failure occurs, it will recover to working state within a certain period of time after repair, and will not cause the system equipment to lose function; the importance coefficient of Class III equipment is w i The value range is set to 7-10.

4. The method for hierarchical evaluation of transient electromagnetic interference in a shipboard power grid according to claim 1, wherein: In step 2, the weighted average sensitivity threshold of the main load equipment at the back end of the distribution box is calculated as : ； Among them, S i is the sensitivity threshold of the i-th load device, w i is the importance coefficient of the i-th load device.

5. The method for hierarchical assessment of transient electromagnetic interference in a shipboard power grid according to claim 1, wherein: In step 3, at the output end of the distribution box in the ship's power grid compartment, a transient spike conducted emission detection device is used to monitor and collect power grid transient spike conducted emission data in real time, wherein the monitoring and collection process is specifically as follows: The time for monitoring and collecting emission data shall not be less than one sea voyage of the ship; During the monitoring and collection process, low-frequency transmitting equipment such as sonar on board the ship should transmit at full power for no less than 2 times; radio frequency transmitting equipment should transmit at rated power for no less than 2 times, with the transmitting frequency taking 2 frequency points within their respective operating frequency bands; The microwave transmitting equipment shall be transmitted at full power for no less than 2 times; High-power equipment whose power exceeds the set value shall be started, operated, stopped or switched to the operating state at least twice; the high-power equipment includes high-pressure air compressors, bilge pumps, hydraulic pumps for the entire ship, and propellers.

6. A method for hierarchical assessment of transient electromagnetic interference in a shipboard power grid according to claim 1 or 5, characterized in that: In step 3, the grid transient spike conduction emission data is monitored and collected, and the grid transient spike interference measurement value is identified therefrom. Specifically, the method is as follows: For the transient spike interference signal collected by monitoring, according to the parameters of the transient spike interference signal including intensity, pulse width, and occurrence frequency, the peak detection and statistical analysis method is used to extract the maximum value from the time-varying signal sequence, and the transient spike interference peak value V is identified by combining the spectrum characteristics and energy distribution of the transient spike signal. PEAK ; The measured value of the transient peak interference of the power grid is: 。 7. The method for hierarchical evaluation of transient electromagnetic interference in a shipboard power grid according to claim 1, wherein: Step 4: Compare the measured value of the power grid transient spike interference with the weighted average sensitivity threshold and calculate the difference between the two; and carry out a graded evaluation of the ship power grid transient spike interference based on the difference result, specifically: Comparison of the power grid transient peak interference measurement value dBV and the weighted average sensitivity threshold , calculate the difference between the two Δ = dBV- ,According to the difference results, the ship power grid transient spike interference grading evaluation is carried out as follows; When Δ<-30dB: No risk level; all load devices in the power distribution box of the power grid compartment can work normally and compatibly, and generally no electromagnetic interference occurs; When Δ is in the range of -30dB to -6dB: low risk level; electromagnetic interference risk on board is controllable; When Δ is in the range of -6dB~0dB: medium risk level; There is a risk of transient spike electromagnetic interference on board; When Δ>0dB: high risk level; electromagnetic interference is potential or has occurred on board.

8. A shipboard power grid transient electromagnetic interference classification assessment system, characterized in that: Includes the following modules: The sensitivity threshold determination module is used to conduct a spike signal sensitivity test, applying simulated transient spike interference signals of different intensities to the common load equipment at the rear end of the distribution box in the ship's power grid compartment one by one, and measuring the transient spike sensitivity threshold of the equipment; specifically: for the common load equipment at the rear end of the distribution box in the ship's power grid compartment, inject a transient spike signal, the transient spike signal pulse width is 10us±20%, the transient spike signal amplitude V P Conduct the test at increasing voltages of 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V, 800V, 850V, and 900V in sequence. The injection time of each amplitude transient spike signal shall not be less than 10 minutes. At the same time, adjust the phase of the transient spike signal. When performance abnormalities or faults occur, record the interference signal threshold level, i.e., the sensitivity threshold of the equipment. During the test, no electromagnetic interference was observed in the equipment, and the sensitivity threshold was recorded as the maximum value of 900V; The weighted average sensitivity threshold calculation module is used to classify devices and assign importance coefficients according to their importance. The module combines the transient spike sensitivity threshold and importance coefficient values ​​of each device obtained in the sensitivity threshold determination module, uses the importance coefficient as the weight, and uses a weighted average method to calculate the weighted average sensitivity threshold of the load devices at the back end of the distribution box. Specifically, ； in, is the calculated weighted average sensitivity threshold of the main load equipment behind the distribution box, S i is the sensitivity threshold of the i-th load device, w i is the importance coefficient of the i-th load device; the devices are divided into Class I to Class III devices according to their importance; The importance coefficient assignment range is set to 1-10; The Class I equipment is the most important equipment on board. After being subjected to transient spike electromagnetic interference, Class I equipment may cause physical damage to the subsystem or equipment, affecting the performance and safety of the entire ship. The importance coefficient w of Class I equipment is set i The value range is 1-3; The Class II equipment refers to equipment that, after being subjected to transient spike electromagnetic interference, causes the subsystem or equipment to degrade in performance or malfunction, only making the system unable to complete some functions without affecting the safety of the system and personnel; the importance coefficient of Class II equipment is w i The value range is set to 4-6; Class III equipment refers to: after being subjected to transient peak electromagnetic interference, the subsystems and equipment of this type will only experience reduced working performance without failure; or even if a failure occurs, it will recover to working state within a certain period of time after repair, and will not cause the system equipment to lose function; the importance coefficient of Class III equipment is w i The value range is set to 7-10; The grid transient spike interference measurement value identification module is used to use the transient spike conducted emission detection device at the output end of the ship's grid compartment distribution box to monitor and collect grid transient spike conducted emission data in real time, and identify the grid transient spike interference measurement value from it; The evaluation module is used to compare the measured value of the power grid transient spike interference with the weighted average sensitivity threshold and calculate the difference between the two; based on the difference result, a graded evaluation of the ship power grid transient spike interference is carried out.

9. A shipboard power grid transient electromagnetic interference classification assessment system according to claim 8, characterized in that: In the grid transient spike interference measurement value identification module, at the output end of the distribution box in the ship's grid compartment, a transient spike conducted emission detection device is used to monitor and collect grid transient spike conducted emission data in real time. The monitoring and collection process is specifically as follows: The time for monitoring and collecting emission data shall not be less than one sea voyage of the ship; During the monitoring and collection process, low-frequency transmitting equipment such as sonar on board the ship should transmit at full power for no less than 2 times; radio frequency transmitting equipment should transmit at rated power for no less than 2 times, with the transmitting frequency taking 2 frequency points within their respective operating frequency bands; The microwave transmitting equipment shall be transmitted at full power for no less than 2 times; High-power equipment with a power exceeding the set value must be started, operated, stopped, or switched to a running state at least twice; such high-power equipment includes high-pressure air compressors, bilge pumps, hydraulic pumps for the entire ship, and propellers; The power grid transient spike interference measurement value identification module monitors and collects power grid transient spike conducted emission data and identifies the power grid transient spike interference measurement value therefrom in the following manner: For the transient spike interference signal collected by monitoring, according to the parameters of the transient spike interference signal including intensity, pulse width, and occurrence frequency, the peak detection and statistical analysis method is used to extract the maximum value from the time-varying signal sequence, and the transient spike interference peak value V is identified by combining the spectrum characteristics and energy distribution of the transient spike signal. PEAK ; The measured value of the transient peak interference of the power grid is: 。 10. The shipboard power grid transient electromagnetic interference classification assessment system according to claim 8, characterized in that: The evaluation module is specifically: Comparison of the power grid transient peak interference measurement value dBV and the weighted average sensitivity threshold , calculate the difference between the two Δ = dBV- ,According to the difference results, the ship power grid transient spike interference grading evaluation is carried out as follows; When Δ< -30dB: No risk level; all load devices in the power distribution box in the power grid compartment can work normally and compatibly, and generally no electromagnetic interference occurs; When Δ is in the range of -30dB to -6dB: low risk level; electromagnetic interference risk on board is controllable; When Δ is in the range of -6dB~0dB: medium risk level; There is a risk of transient spike electromagnetic interference on board; When Δ>0dB: high risk level; electromagnetic interference is potential or has occurred on board.

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