Control method of mobile energy storage power station for ship and energy storage system

Abstract

The invention relates to the technical field of energy storage systems, in particular to a control method of a mobile energy storage power station for a ship and an energy storage system.The energy storage system comprises an energy storage unit, an energy management system, a harmonic analysis sensor and an energy storage converter; the control method mainly comprises the following steps that firstly, an energy management system monitors parameters of an energy storage unit and the load condition of a power grid in real time, and a harmonic analysis sensor collects electric energy quality data and calculates total harmonic distortion; then harmonic components are analyzed through a fast Fourier transform algorithm and a sliding window mechanism, and transient harmonic detection precision is improved by using a multi-resolution wavelet transform technology; and when harmonic distortion exceeds the limit, a suppression mechanism is triggered to adjust parameters of the energy storage converter, so that the total harmonic distortion of the system is strictly controlled within 5%, the influence of harmonic pollution on a ship power grid and electric equipment is effectively avoided, and the stability and purity of electric energy output are ensured.

Description

Technical Field

[0001] This invention relates to the field of energy storage system technology, specifically to a control method and energy storage system for a mobile energy storage power station for ships. Background Technology

[0002] In the field of shipping and offshore operations, mobile energy storage power stations serve as an important supplement to the ship's power system, undertaking key tasks such as peak load regulation and emergency power supply. Their operational stability and power quality directly affect the normal operation of the ship's propulsion system, navigation and communication equipment, and various electrical loads.

[0003] However, when traditional energy storage systems are connected to the grid with ship generators, a large number of harmonic current components are easily generated due to factors such as the switching action of the energy storage converter, the nonlinear characteristics of the load, and sudden changes in the grid load. This leads to voltage harmonic distortion, causing the total harmonic distortion of the system to exceed the standard. This not only affects the service life of precision electrical equipment, but may also interfere with the frequency and voltage stability of the ship's power grid. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned shortcomings in the prior art by providing a control method and energy storage system for a mobile energy storage power station for ships.

[0005] The objective of this invention is achieved through the following technical solution: a control method for a mobile energy storage power station for ships, wherein the mobile energy storage power station for ships includes an energy storage system; the energy storage system includes an energy storage unit, an energy management system, a harmonic analysis sensor, and an energy storage converter; the control method for the mobile energy storage power station for ships includes the following steps: S1. Monitor basic data in real time through the energy management system; the basic data includes the voltage, current and temperature of the energy storage unit, and also the load status of the energy storage system; S2. Collect power quality data of the energy storage system during operation using the harmonic analysis sensor, including current data; generate voltage harmonic graphs based on the collected current data, and calculate the total harmonic distortion of the system. S3. The energy management system adopts the fast Fourier transform algorithm to perform real-time frequency domain analysis on the harmonic current components extracted from the current data, and introduces a sliding window mechanism to periodically update the basic data and power quality data. S4. The energy management system uses multi-resolution wavelet transform technology to decompose the harmonic signals extracted from the power quality data into multiple scales to improve the detection accuracy and response speed of transient harmonics. When the harmonic distortion after decomposition exceeds the set threshold, the harmonic suppression mechanism is triggered. S5. When the harmonic distortion exceeds the set threshold, the energy management system dynamically adjusts the trigger angle of the IGBT in the energy storage converter to optimize the output current waveform, so that the total harmonic distortion of the system is no more than 5%. S6. During the harmonic suppression mechanism process, the output power of the energy storage unit is adjusted synchronously to avoid the impact of sudden load changes on the energy storage system.

[0006] The present invention is further configured such that the current data includes the fundamental current, each harmonic current component and the background harmonic current.

[0007] The present invention further specifies that the formula for calculating the total harmonic distortion of the system is: ; in This represents the amplitude of the fundamental current. For the first The amplitude of the second harmonic current; Background harmonic current; Indicates the highest order in the harmonic calculation; , and These are weighting coefficients, and they satisfy... ; The sensitivity coefficient of the equipment ranges from 0.8 to 1.2. This is a constant offset, with a value ranging from 2 to 5. The harmonic weight inflection point is set to 10-15.

[0008] The present invention is further configured such that the power quality data also includes voltage data; In step S4, the harmonic signal includes a current harmonic signal and a voltage harmonic signal. The current harmonic signal is composed of harmonic current components, and the voltage harmonic signal is generated by the current harmonic components flowing through the power grid impedance.

[0009] The present invention is further configured such that the energy storage unit performs real-time fault diagnosis on the energy storage unit and the energy storage converter through a variety of fault detection algorithms, and generates fault alarm information including fault location and fault type; When the energy management system detects a fault in the energy storage unit, it automatically selects the optimal repair strategy based on the fault type and provides real-time feedback on the fault diagnosis results and repair progress.

[0010] The present invention is further configured such that, during the operation of the energy storage system, if a certain energy storage unit fails, the energy management system quickly identifies the failed energy storage unit through the fault detection module and automatically generates a fault simulation analysis report including changes in harmonic current components and power fluctuations before and after the fault. The simulation analysis adopts the following dynamic power allocation algorithm: ; in This indicates that after a fault occurs, the energy storage unit The new power output, Indicates energy storage unit The current power output, Indicates the faulty system in time Fault power at that time This indicates the total number of energy storage units in the energy storage power station. This indicates the number of available energy storage units remaining after a failure.

[0011] The present invention is further configured such that the energy management system quickly identifies the faulty energy storage unit through the fault detection module, and automatically generates a fault simulation analysis report including changes in harmonic current components and power fluctuations before and after the fault; the remaining effective energy storage units automatically share the load of the faulty energy storage unit to ensure the stability of the energy storage system, while ensuring that the total harmonic distortion of the system is not greater than 5% by real-time monitoring of the total harmonic distortion of the system; The energy storage system dynamically adjusts the IGBT trigger angle and power output curve of the energy storage converter corresponding to the remaining effective energy storage units to maintain a stable load distribution for the remaining energy storage units and avoid overload of a single energy storage unit.

[0012] The present invention is further configured such that, during the simulation analysis phase after a failure in the energy storage system, the energy management system employs a fast Fourier transform algorithm to perform frequency domain analysis on the harmonic current components extracted from the current data before and after the failure point, and dynamically adjusts the power allocation of each effective energy storage unit based on the analysis results to ensure that the remaining energy storage system continues to operate stably and that the total harmonic distortion of the system is not greater than 5%. The energy management system has a sliding window mechanism, which monitors the operating status of the energy storage system in real time by periodically updating the monitoring data. Under the conditions of sudden load changes in the energy storage system or simultaneous operation of multiple energy storage units, it ensures that the total harmonic distortion of the system meets the power quality requirements of the energy storage system. The energy management system has remote diagnostic and simulation functions. After a fault occurs, it can quickly call up power quality data and harmonic analysis results before and after the fault through the remote maintenance platform to complete the fault analysis, generate harmonic simulation graphics, and provide optimization solutions.

[0013] The present invention is further configured such that the energy storage converter has an overcurrent protection module and an overvoltage protection module.

[0014] An energy storage system for a mobile energy storage power station on a ship includes an energy storage unit, an energy management system, a harmonic analysis sensor, and an energy storage converter; it also includes: Monitoring module: used for real-time monitoring of basic data; the basic data includes the voltage, current and temperature of the energy storage unit, and also the load status of the energy storage system; Acquisition and Calculation Module: Used to acquire power quality data during the operation of the energy storage system, including current data; used to generate voltage harmonic graphs based on the acquired current data and calculate the total harmonic distortion of the system; Real-time frequency domain analysis module: It adopts the fast Fourier transform algorithm to perform real-time frequency domain analysis on the harmonic current components extracted from the current data, and introduces a sliding window mechanism to periodically update the basic data and power quality data. Multi-resolution wavelet transform module: Through multi-resolution wavelet transform technology, the harmonic signals extracted from power quality data are decomposed into multiple scales to improve the detection accuracy and response speed of transient harmonics. When the harmonic distortion after decomposition exceeds the set threshold, the harmonic suppression mechanism is triggered. Output current waveform optimization module: When harmonic distortion exceeds a set threshold, the energy management system dynamically adjusts the trigger angle of the IGBT in the energy storage converter to optimize the output current waveform, ensuring that the total harmonic distortion of the system does not exceed 5%. Output power regulation module: Used to synchronously regulate the output power of the energy storage unit during the harmonic suppression mechanism process, so as to avoid the impact of sudden load changes on the energy storage system.

[0015] The beneficial effects of this invention are as follows: This invention accurately collects power quality data through a harmonic analysis sensor, and combines the Fast Fourier Transform algorithm and multi-resolution wavelet transform technology to achieve high-precision and rapid detection of harmonic current components and transient harmonics; when harmonic distortion exceeds the limit, the total harmonic distortion of the system can be strictly controlled within 5% by dynamically adjusting the trigger angle of the energy storage converter IGBT, effectively avoiding the impact of harmonic pollution on the ship's power grid and electrical equipment, and ensuring the stability and purity of power output. Attached Figure Description

[0016] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0017] The present invention will be further described in conjunction with the following embodiments.

[0018] Depend on Figure 1 As can be seen, the control method for a mobile energy storage power station for ships described in this embodiment includes an energy storage system; the energy storage system includes an energy storage unit, an energy management system, a harmonic analysis sensor, and an energy storage converter; the control method for the mobile energy storage power station for ships includes the following steps: S1. Real-time monitoring of basic data through the energy management system; the basic data includes the voltage, current, and temperature of the energy storage units, as well as the load status of the energy storage system; the energy management system, as the core control center of the energy storage system, monitors the voltage and current of the energy storage units, which can directly reflect the battery charging and discharging status (such as avoiding battery bulging caused by overcharging or capacity decay caused by over-discharging), while the temperature data is related to battery thermal safety (preventing safety risks caused by thermal runaway); at the same time, monitoring the load status of the energy storage system can accurately capture the real-time power demand of the ship's power grid, providing basic data support for subsequent harmonic suppression and power regulation; through this step, dual real-time perception of the system's safety status and load demand can be achieved, avoiding battery safety risks in advance, and providing an accurate load benchmark for the formulation of subsequent control strategies, avoiding blind control due to data gaps, and ensuring the stability of the system's initial operating state.

[0019] S2. Power quality data during the operation of the energy storage system is collected using the harmonic analysis sensor. The power quality data includes current data. A voltage harmonic graph is generated based on the collected current data, and the total harmonic distortion of the system is calculated. The harmonic analysis sensor has high-precision current sampling capability, which can capture subtle changes in the fundamental, harmonic, and background harmonics in the current (these components are the core causes of power quality degradation in ship power grids). Since voltage harmonics are indirectly generated when current harmonics flow through the impedance of ship power grid lines, the voltage harmonic graph generated based on the collected current data can intuitively present the harmonic distribution characteristics. The total harmonic distortion of the system is then calculated using a specific formula, which can transform power quality from a qualitative description into a quantitative indicator, providing a clear basis for subsequent harmonic suppression strategies. This step can obtain accurate power quality data, visualization, and quantitative indicators, avoiding reliance on experience to judge harmonic problems. It provides a complete data source for subsequent harmonic analysis, prevents incomplete suppression due to incomplete harmonic information, and ensures the comprehensiveness of power quality assessment.

[0020] S3. The energy management system employs a Fast Fourier Transform (FFT) algorithm to perform real-time frequency domain analysis on the harmonic current components extracted from the current data. A sliding window mechanism is introduced to periodically update the basic data and power quality data. The FFT algorithm can transform the time-domain current waveform into frequency-domain harmonic components (e.g., accurately identifying the frequency and amplitude of different harmonics such as the 3rd and 5th orders), achieving precise harmonic localization and solving the problem that traditional time-domain analysis cannot distinguish harmonic frequencies. Simultaneously, a sliding window mechanism (e.g., setting an update cycle of 100ms / window) is introduced to periodically replace old data and incorporate new data, avoiding data lag that could cause the analysis results to become out of sync with the actual operating conditions of the ship's power grid. Through this step, the analysis accuracy of the harmonic current components can be improved to a dual-dimensional level of frequency and amplitude. Furthermore, the real-time updated data ensures that the analysis results are synchronized with the system's operating status, providing a "real-time guarantee" for the dynamic adjustment of subsequent harmonic suppression strategies and avoiding the problem that static analysis cannot cope with fluctuations in ship load (e.g., sudden acceleration or deceleration of the propulsion system).

[0021] S4. The energy management system uses multi-resolution wavelet transform technology to decompose harmonic signals extracted from power quality data at multiple scales, thereby improving the detection accuracy and response speed of transient harmonics. When the harmonic distortion after decomposition exceeds a set threshold, a harmonic suppression mechanism is triggered. Multi-resolution wavelet transform technology has multi-scale analysis capabilities and can decompose harmonic signals in different frequency ranges in layers. It is particularly adept at capturing transient harmonics with short durations (e.g., milliseconds) and abrupt amplitude changes in the ship's power grid (traditional FFT algorithms have a significant lag in detecting transient signals). Simultaneously, based on the power supply quality requirements of the ship's power grid for precision equipment (e.g., navigation and communication systems), a harmonic distortion threshold (e.g., total system harmonic distortion > 5%) is set, forming a closed-loop logic of detection-judgment-triggering to ensure that suppression measures are immediately activated when harmonics exceed the standard. This step can compress the detection response speed of transient harmonics from the second level to the millisecond level, avoiding equipment failures (e.g., radar signal interference) caused by the accumulation of transient harmonics. At the same time, the threshold triggering mechanism enables automated activation of harmonic suppression, reducing delays in manual intervention and ensuring the power supply stability of critical ship equipment.

[0022] S5. When harmonic distortion exceeds the set threshold, the energy management system dynamically adjusts the trigger angle of the IGBT in the energy storage converter to optimize the output current waveform, ensuring that the total harmonic distortion of the system is no greater than 5%. The trigger angle of the IGBT in the energy storage converter directly determines the conduction sequence of the output current. By dynamically adjusting the trigger angle, specific harmonic components of the current can be selectively offset (e.g., adjusting the angle to offset the impact of the 3rd harmonic on the power grid), making the output current approach an ideal sine wave. Strictly controlling the total harmonic distortion of the system to within 5% is a core standard for the power supply quality of precision electrical equipment (such as propulsion system motors and navigation equipment) in a ship's power grid. This step can quickly control harmonic distortion within a safe range, avoiding the shortening of equipment life caused by harmonics (e.g., additional losses in motors due to harmonics), while ensuring that the output power meets the power supply requirements of critical ship equipment, directly guaranteeing the safety of ship navigation.

[0023] S6. During the harmonic suppression mechanism, the output power of the energy storage unit is synchronously adjusted to avoid the impact of sudden load changes on the energy storage system. Adjusting the IGBT trigger angle to suppress harmonics may cause fluctuations in the output power of the energy storage converter. If the energy storage unit power is not adjusted synchronously, it can easily trigger sudden load changes in the ship's power grid (such as sudden power spikes and drops), thereby interfering with the stability of the grid voltage and frequency. By synchronously adjusting the output power of the energy storage unit, the converter power fluctuations can be balanced, maintaining the stability of the total system power and avoiding the impact of sudden load changes on the power grid. This step achieves coordinated control of harmonic suppression and power stability, preventing new grid fluctuations caused by harmonic suppression, ensuring the stability of the ship's power grid voltage and frequency, avoiding power supply interference to sensitive equipment such as radar and communications, and ensuring the coordinated and stable operation of the entire energy storage system and the ship's power grid.

[0024] The control method for a mobile energy storage power station for ships described in this embodiment includes the fundamental current, harmonic current components, and background harmonic current in the current data.

[0025] The control method for a mobile energy storage power station for ships described in this embodiment uses the following formula for calculating the total harmonic distortion of the system: ; in This represents the amplitude of the fundamental current. For the first The amplitude of the second harmonic current; Background harmonic current; Indicates the highest order in the harmonic calculation; , and These are weighting coefficients, and they satisfy... ; The sensitivity coefficient of the equipment ranges from 0.8 to 1.2. This is a constant offset, with a value ranging from 2 to 5. The harmonic weight inflection point is set to 10-15.

[0026] Specifically, the fundamental current is the core effective component of power transmission, harmonic currents are the main sources of interference that degrade power quality, and background harmonic currents come from inherent interference in the ship's electrical grid (such as other electrical equipment). The three together determine power quality. The introduction of weighting coefficients (α, β, γ) is because the three have different degrees of influence on the ship's electrical grid (e.g., the fundamental current has a higher weight and is directly related to the effectiveness of power supply), which can avoid the deviation caused by traditional equal weight calculation. The equipment sensitivity coefficient (K) is adapted to the harmonic tolerance characteristics of different equipment on the ship, such as lithium batteries and energy storage converters (e.g., lithium batteries are more sensitive to harmonics, so K can be taken as 1.2 to strengthen their protection). The constant offset (C) is used to correct the small measurement error of the background harmonic current to ensure the accuracy of the calculation. The harmonic weight inflection point (M=10-15) distinguishes the influence of high and low order harmonics (lower order harmonics have a greater impact on ship propulsion motors and navigation equipment, and have a higher weight before the inflection point). This formula enables the total harmonic distortion calculation results of the system to accurately reflect the actual power quality of the ship's energy storage system, avoiding energy waste caused by excessive suppression of harmonics or equipment failures caused by insufficient suppression (such as increased additional losses in the propulsion motor), and providing a quantitative basis for subsequent harmonic control.

[0027] The control method for a mobile energy storage power station for ships described in this embodiment includes voltage data as part of the power quality data. In step S4, the harmonic signal includes a current harmonic signal and a voltage harmonic signal. The current harmonic signal is composed of harmonic current components, and the voltage harmonic signal is generated by the current harmonic components flowing through the power grid impedance.

[0028] In marine electrical networks, current harmonic signals are a source of interference (such as the switching action of IGBTs in energy storage converters and the nonlinear characteristics of loads). When current harmonics flow through the line impedance of the marine electrical network (such as cable resistance and inductance), a voltage drop is generated, which in turn forms voltage harmonic signals. Current harmonics may cause motors to overheat, while voltage harmonics may cause voltage instability in navigation equipment and communication systems. If only current data is monitored and voltage data is ignored, the hidden dangers caused by voltage harmonics are easily overlooked. By simultaneously collecting voltage data and distinguishing between current and voltage harmonic signals, the power quality status can be comprehensively assessed, avoiding equipment failures due to missing monitoring dimensions (such as signal interruptions in radar systems caused by voltage harmonics), and ensuring the power supply stability of critical marine equipment.

[0029] The control method of a mobile energy storage power station for ships described in this embodiment involves the energy storage unit performing real-time fault diagnosis on the energy storage unit and the energy storage converter through various fault detection algorithms, and generating fault alarm information including fault location and fault type. When the energy management system detects a fault in the energy storage unit, it automatically selects the optimal repair strategy based on the fault type and provides real-time feedback on the fault diagnosis results and repair progress.

[0030] Shipboard energy storage systems exhibit a variety of fault types (such as lithium battery overheating, energy storage converter overcurrent, and voltage anomalies), making it difficult for a single detection algorithm to cover all of them (for example, threshold algorithms are good at detecting sudden faults, while trend analysis algorithms are good at capturing progressive faults). Therefore, employing multiple fault detection algorithms can improve diagnostic coverage and accuracy. Different faults have different risk levels and require different handling methods (for example, lithium battery overheating requires prioritizing cooling, while converter overcurrent requires cutting off the unit's power supply). Selecting a repair strategy based on the fault type can avoid the inefficiency or escalation of faults caused by a one-size-fits-all approach. Real-time feedback of diagnostic results and repair progress allows offshore maintenance personnel to monitor the system status in real time, reducing on-site troubleshooting time. This design improves fault diagnosis accuracy, effectively shortens fault handling time, and significantly reduces manual maintenance costs and the impact of faults on ship operations.

[0031] The control method for a mobile energy storage power station for ships described in this embodiment involves the energy management system quickly identifying the faulty energy storage unit through a fault detection module during the operation of the energy storage system. The system automatically generates a fault simulation analysis report containing changes in harmonic current components and power fluctuations before and after the fault. The simulation analysis employs the following dynamic power allocation algorithm: ; in This indicates that after a fault occurs, the energy storage unit The new power output, Indicates energy storage unit The current power output, Indicates the faulty system in time Fault power at that time This indicates the total number of energy storage units in the energy storage power station. This indicates the number of available energy storage units remaining after a failure.

[0032] During ship operations, energy storage systems must continuously supply power to critical equipment such as propulsion and navigation. If a single energy storage unit fails and goes offline, it can easily lead to a decrease in total power (such as affecting the propulsion system's power), or the remaining effective units may be overloaded and damaged due to concentrated load. This dynamic power allocation algorithm, through fault power averaging logic (distributing the power of the faulty unit evenly to T-1 effective units), can ensure the stability of the system's total power and avoid power outages. Simultaneously, it generates a fault simulation analysis report. By comparing harmonic and power data before and after the fault, it can accurately pinpoint the scope of the fault's impact on the system (such as whether it causes a sudden increase in harmonics), providing a data-driven fault profile for subsequent maintenance. This design avoids insufficient power supply to ship equipment caused by faults, prevents overload of effective energy storage units, and the report also reduces the time spent on blind troubleshooting by maintenance personnel, improving fault handling efficiency.

[0033] The control method for a mobile energy storage power station for ships described in this embodiment involves an energy management system that rapidly identifies faulty energy storage units through a fault detection module and automatically generates a fault simulation analysis report including changes in harmonic current components and power fluctuations before and after the fault. The remaining effective energy storage units automatically share the load of the faulty unit to ensure the stability of the energy storage system. Simultaneously, by monitoring the total harmonic distortion (THD) of the system in real time, the system's THD is guaranteed to be no greater than 5%. The energy storage system dynamically adjusts the IGBT trigger angle and power output curve of the energy storage converter corresponding to the remaining effective energy storage units to maintain a stable load distribution for the remaining energy storage units and avoid overload of a single energy storage unit.

[0034] When effective energy storage units share the load of faulty units, changes in power output may induce new harmonics (such as current waveform distortion caused by a sudden power surge). If not intervened in time, this can easily lead to excessive total harmonic distortion (THD) of the system. By dynamically adjusting the IGBT trigger angle of the energy storage converter, the newly added harmonics can be offset, maintaining a stable current waveform. At the same time, adjusting the power output curve (such as using a smooth rising / falling curve) can avoid the impact of sudden load changes on effective units (such as preventing lithium batteries from having their lifespan shortened due to instantaneous high-power discharge). Real-time monitoring of THD ensures that the power quality always meets shipboard standards (THD ≤ 5%). Through this design, even in a fault state, the energy storage system can still maintain high-quality power supply, avoiding system paralysis caused by fault propagation, while protecting the remaining effective units and extending the overall service life of the energy storage system.

[0035] The control method for a mobile energy storage power station for ships described in this embodiment includes a simulation analysis phase after a fault occurs in the energy storage system. The energy management system uses a fast Fourier transform algorithm to perform frequency domain analysis on the harmonic current components extracted from the current data before and after the fault point. Based on the analysis results, the power allocation of each effective energy storage unit is dynamically adjusted to ensure that the remaining energy storage system continues to operate stably and that the total harmonic distortion of the system is not greater than 5%. The energy management system has a sliding window mechanism, which monitors the operating status of the energy storage system in real time by periodically updating the monitoring data. Under the conditions of sudden load changes in the energy storage system or simultaneous operation of multiple energy storage units, it ensures that the total harmonic distortion of the system meets the power quality requirements of the energy storage system. The energy management system has remote diagnostic and simulation functions. After a fault occurs, it can quickly call up power quality data and harmonic analysis results before and after the fault through the remote maintenance platform to complete the fault analysis, generate harmonic simulation graphics, and provide optimization solutions.

[0036] The Fast Fourier Transform (FFT) algorithm can accurately pinpoint changes in harmonic components before and after a fault (such as a sudden increase in the amplitude of a harmonic at a certain frequency), providing a targeted basis for power distribution adjustments. A sliding window mechanism (e.g., 100ms / window) can periodically update data, ensuring that total harmonic distortion (THD) monitoring is not lagging during sudden changes in ship load (such as sudden acceleration of the propulsion system) or when multiple units are operating in parallel. Remote diagnostics addresses the pain point of inconvenient offshore maintenance, enabling remote analysis through data transmission without requiring the maintenance vessel to immediately go to sea. This design effectively shortens the time required for the system to recover after a fault, effectively addressing power quality control under complex ship operating conditions, while significantly reducing the time and economic costs of offshore maintenance.

[0037] This embodiment describes a control method for a mobile energy storage power station for ships, wherein the energy storage converter has an overcurrent protection module and an overvoltage protection module.

[0038] The energy storage system of a mobile energy storage power station for ships described in this embodiment includes an energy storage unit, an energy management system, a harmonic analysis sensor, and an energy storage converter; it also includes: Monitoring module: used for real-time monitoring of basic data; the basic data includes the voltage, current and temperature of the energy storage unit, and also the load status of the energy storage system; Acquisition and Calculation Module: Used to acquire power quality data during the operation of the energy storage system, including current data; used to generate voltage harmonic graphs based on the acquired current data and calculate the total harmonic distortion of the system; Real-time frequency domain analysis module: It adopts the fast Fourier transform algorithm to perform real-time frequency domain analysis on the harmonic current components extracted from the current data, and introduces a sliding window mechanism to periodically update the basic data and power quality data. Multi-resolution wavelet transform module: Through multi-resolution wavelet transform technology, the harmonic signals extracted from power quality data are decomposed into multiple scales to improve the detection accuracy and response speed of transient harmonics. When the harmonic distortion after decomposition exceeds the set threshold, the harmonic suppression mechanism is triggered. Output current waveform optimization module: When harmonic distortion exceeds a set threshold, the energy management system dynamically adjusts the trigger angle of the IGBT in the energy storage converter to optimize the output current waveform, ensuring that the total harmonic distortion of the system does not exceed 5%. Output power regulation module: Used to synchronously regulate the output power of the energy storage unit during the harmonic suppression mechanism process, so as to avoid the impact of sudden load changes on the energy storage system.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A control method for a mobile energy storage power station for ships, characterized in that: The mobile energy storage power station for ships includes an energy storage system; the energy storage system includes an energy storage unit, an energy management system, a harmonic analysis sensor, and an energy storage converter; the control method of the mobile energy storage power station for ships includes the following steps: S1. Monitor basic data in real time through the energy management system; the basic data includes the voltage, current and temperature of the energy storage unit, and also the load status of the energy storage system; S2. Collect power quality data of the energy storage system during operation using the harmonic analysis sensor, including current data; generate voltage harmonic graphs based on the collected current data, and calculate the total harmonic distortion of the system. S3. The energy management system adopts the fast Fourier transform algorithm to perform real-time frequency domain analysis on the harmonic current components extracted from the current data, and introduces a sliding window mechanism to periodically update the basic data and power quality data. S4. The energy management system uses multi-resolution wavelet transform technology to decompose the harmonic signals extracted from the power quality data into multiple scales to improve the detection accuracy and response speed of transient harmonics. When the harmonic distortion after decomposition exceeds the set threshold, the harmonic suppression mechanism is triggered. S5. When the harmonic distortion exceeds the set threshold, the energy management system dynamically adjusts the trigger angle of the IGBT in the energy storage converter to optimize the output current waveform, so that the total harmonic distortion of the system is no more than 5%. S6. During the harmonic suppression mechanism process, the output power of the energy storage unit is adjusted synchronously to avoid the impact of sudden load changes on the energy storage system.

2. The control method for a mobile energy storage power station for ships according to claim 1, characterized in that: The current data includes the fundamental current, each harmonic current component, and the background harmonic current.

3. The control method for a mobile energy storage power station for ships according to claim 2, characterized in that: The formula for calculating the total harmonic distortion of the system is as follows: ； in This represents the amplitude of the fundamental current. For the first The amplitude of the second harmonic current; Background harmonic current; Indicates the highest order in the harmonic calculation; , and These are weighting coefficients, and they satisfy... ; The sensitivity coefficient of the equipment ranges from 0.8 to 1.

2. This is a constant offset, with a value ranging from 2 to 5. The harmonic weight inflection point is set to 10-15.

4. The control method for a mobile energy storage power station for ships according to claim 1, characterized in that: The power quality data also includes voltage data; In step S4, the harmonic signal includes a current harmonic signal and a voltage harmonic signal. The current harmonic signal is composed of harmonic current components, and the voltage harmonic signal is generated by the current harmonic components flowing through the power grid impedance.

5. The control method for a mobile energy storage power station for ships according to claim 1, characterized in that: The energy storage unit uses multiple fault detection algorithms to perform real-time fault diagnosis on the energy storage unit and the energy storage converter, and generates fault alarm information including fault location and fault type. When the energy management system detects a fault in the energy storage unit, it automatically selects the optimal repair strategy based on the fault type and provides real-time feedback on the fault diagnosis results and repair progress.

6. The control method for a mobile energy storage power station for ships according to claim 1, characterized in that: During the operation of the energy storage system, if a fault occurs in an energy storage unit, the energy management system quickly identifies the faulty energy storage unit through the fault detection module and automatically generates a fault simulation analysis report that includes changes in harmonic current components and power fluctuations before and after the fault. The simulation analysis uses the following dynamic power allocation algorithm: ； in This indicates that after a fault occurs, the energy storage unit The new power output, Indicates energy storage unit The current power output, Indicates the faulty system in time Fault power at that time This indicates the total number of energy storage units in the energy storage power station. This indicates the number of available energy storage units remaining after a failure.

7. The control method for a mobile energy storage power station for ships according to claim 6, characterized in that: The energy management system quickly identifies faulty energy storage units through a fault detection module and automatically generates a fault simulation analysis report that includes changes in harmonic current components and power fluctuations before and after the fault. The remaining effective energy storage units automatically share the load of the faulty energy storage unit to ensure the stability of the energy storage system. At the same time, it ensures that the total harmonic distortion of the system does not exceed 5% by monitoring the total harmonic distortion of the system in real time. The energy storage system dynamically adjusts the IGBT trigger angle and power output curve of the energy storage converter corresponding to the remaining effective energy storage units to maintain a stable load distribution for the remaining energy storage units and avoid overload of a single energy storage unit.

8. The control method for a mobile energy storage power station for ships according to claim 7, characterized in that: During the simulation analysis phase after a failure in the energy storage system, the energy management system uses a fast Fourier transform algorithm to perform frequency domain analysis on the harmonic current components extracted from the current data before and after the failure point. Based on the analysis results, it dynamically adjusts the power allocation of each effective energy storage unit to ensure that the remaining energy storage system continues to operate stably and that the total harmonic distortion of the system is no greater than 5%. The energy management system has a sliding window mechanism, which monitors the operating status of the energy storage system in real time by periodically updating the monitoring data. Under the conditions of sudden load changes in the energy storage system or simultaneous operation of multiple energy storage units, it ensures that the total harmonic distortion of the system meets the power quality requirements of the energy storage system. The energy management system has remote diagnostic and simulation functions. After a fault occurs, it can quickly call up power quality data and harmonic analysis results before and after the fault through the remote maintenance platform to complete the fault analysis, generate harmonic simulation graphics, and provide optimization solutions.

9. The control method for a mobile energy storage power station for ships according to claim 1, characterized in that: The energy storage converter has an overcurrent protection module and an overvoltage protection module.

10. An energy storage system for a mobile energy storage power station on a ship, characterized in that: Includes energy storage units, energy management systems, harmonic analysis sensors, and energy storage converters; also includes: Monitoring module: used for real-time monitoring of basic data; the basic data includes the voltage, current and temperature of the energy storage unit, and also the load status of the energy storage system; Acquisition and Calculation Module: Used to acquire power quality data during the operation of the energy storage system, including current data; used to generate voltage harmonic graphs based on the acquired current data and calculate the total harmonic distortion of the system; Real-time frequency domain analysis module: It adopts the fast Fourier transform algorithm to perform real-time frequency domain analysis on the harmonic current components extracted from the current data, and introduces a sliding window mechanism to periodically update the basic data and power quality data. Multi-resolution wavelet transform module: Through multi-resolution wavelet transform technology, the harmonic signals extracted from power quality data are decomposed into multiple scales to improve the detection accuracy and response speed of transient harmonics. When the harmonic distortion after decomposition exceeds the set threshold, the harmonic suppression mechanism is triggered. Output current waveform optimization module: When harmonic distortion exceeds a set threshold, the energy management system dynamically adjusts the trigger angle of the IGBT in the energy storage converter to optimize the output current waveform, ensuring that the total harmonic distortion of the system does not exceed 5%. Output power regulation module: Used to synchronously regulate the output power of the energy storage unit during the harmonic suppression mechanism process, so as to avoid the impact of sudden load changes on the energy storage system.

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