A power system suitable for pure electric port tugboats

Abstract

This invention relates to the field of marine propulsion technology and discloses a power system suitable for pure electric port tugboats. The system includes: a power battery pack, a DC power distribution board, an AC power distribution board, an auxiliary day-use module, a charging box, and a control module. The power battery pack is connected to the DC power distribution board, the auxiliary day-use module, and the charging box. The DC power distribution board is connected to the AC power distribution board and the auxiliary day-use module. The AC power distribution board includes several day-use transformers. The auxiliary day-use module includes an auxiliary day-use inverter, an auxiliary sine filter, and an auxiliary day-use transformer. The control module is used to switch the power supply mode of the power battery pack according to the ship's status, control the operating status of the DC power distribution board, the AC power distribution board, and the auxiliary day-use module based on the switched power supply mode, and determine the discharge priority of each power battery based on its charge status. This invention ensures the stability and efficiency of the pure electric port tugboat power system.

Description

Technical Field

[0001] This invention relates to the field of marine propulsion technology, and more specifically, to a propulsion system suitable for pure electric port tugboats. Background Technology

[0002] With the continuous development of maritime trade, the requirements for ships in terms of green and low-carbon operation and efficiency are increasing. Ship electrification, as an important path to achieve the green and low-carbon transformation of ships, has become an important development trend in the field of ship power.

[0003] Pure electric port tugboats are vessels that assist large ships in entering and leaving ports, berthing and unberthing, turning around, moving berths, and towing barges. Because the duration of each operation of a pure electric port tugboat varies, and the waiting time at the dock or anchorage is not fixed, traditional pure electric port tugboats need to continuously use DC power distribution boards and related auxiliary equipment to ensure that the batteries can continuously supply power to the ship's daily equipment during the waiting period. This results in a certain amount of power consumption, and the DC power distribution boards themselves also generate heat. All of these constitute ineffective power consumption of the power system, thereby reducing the stability and efficiency of the power system. How to reduce ineffective power consumption during the waiting period is the key to improving the service life of pure electric port tugboats.

[0004] Therefore, it is necessary to design a power system suitable for pure electric port tugboats to solve the problems existing in the current technology. Summary of the Invention

[0005] In view of this, the present invention proposes a power system suitable for pure electric port tugboats, aiming to solve the problem that the continuous use of DC power distribution boards and related auxiliary equipment results in a certain amount of power consumption, which reduces the stability and efficiency of the power system.

[0006] This invention proposes a power system suitable for pure electric port tugboats, comprising:

[0007] Power battery pack, DC power distribution board, AC power distribution board, auxiliary daily use module, charging box and control module;

[0008] The power battery pack is connected to the DC power distribution board, the auxiliary daily use module and the charging box;

[0009] The charging box is used to charge the power battery pack, which includes a plurality of power batteries, each of which is used to provide electrical energy.

[0010] The DC power distribution board is connected to the AC power distribution board and the auxiliary daily use module;

[0011] The DC power distribution board includes several DC converters, a day-use inverter, and a main drive inverter, with the several DC converters connected to the day-use inverter and the main drive inverter;

[0012] The AC distribution board includes several day-use transformers;

[0013] The auxiliary daily use module includes an auxiliary daily use inverter, an auxiliary sine filter, and an auxiliary daily use transformer. One end of the auxiliary sine filter is connected to the auxiliary daily use inverter, and the other end of the auxiliary sine filter is connected to the auxiliary daily use transformer.

[0014] The control module is connected to the power battery pack, DC power distribution board, AC power distribution board and auxiliary daily use module. The control module is used to switch the power supply mode of the power battery pack according to the ship's status, control the working status of the DC power distribution board, AC power distribution board and auxiliary daily use module based on the switched power supply mode, and determine the discharge priority of each power battery based on the charge status of each power battery in the power battery pack.

[0015] Furthermore, the power system suitable for pure electric port tugboats also includes: each of the main propulsion inverters is connected to the main propulsion motor.

[0016] Furthermore, when switching the power supply mode of the power battery pack according to the ship's status, and controlling the operating status of the DC power distribution board, AC power distribution board, and auxiliary daily use module based on the switched power supply mode, the following is included:

[0017] When the ship is in a waiting state, the power supply mode of the power battery pack is a standby power supply mode. In the standby power supply mode, the power battery pack supplies power to the AC power distribution board, and the DC power distribution board is in a closed state.

[0018] When the vessel is in operation, the power supply mode of the power battery pack is the power supply mode, in which the power battery pack supplies power to the DC power distribution board, and the DC power distribution board is in the open state.

[0019] Furthermore, when determining the discharge priority of each power battery based on the state of charge of each power battery in the power battery pack, the method includes:

[0020] When the power supply mode of the power battery pack is determined to be standby power supply mode or power supply mode, the power change value of each power battery per unit time is obtained, and the historical average power change value is determined.

[0021] When the change in charge of all power batteries within the unit time is less than or equal to the historical average change in charge, it is determined that the output power of the power batteries will not be adjusted, and the discharge priority of each power battery is determined according to the battery capacity of each power battery.

[0022] If the change in the power battery charge within a unit of time is greater than the historical average change in charge charge, then it is determined that the output power of the power battery should be adjusted.

[0023] Furthermore, when determining whether to adjust the output power of the power battery, the following are included:

[0024] Determine the difference between the change in the power battery's charge and the historical average change in charge, and compare the difference with the historical adjustment set;

[0025] The historical adjustment set includes several historical change differences and several historical adjustment factors, and each historical change difference corresponds to a historical adjustment factor.

[0026] If the historical adjustment set contains a historical change difference equal to the change difference, then the adjustment factor for the output power of the power battery is determined based on the historical adjustment set; otherwise, the adjustment factor for the output power of the power battery is determined based on the historical adjustment set and the power adjustment model.

[0027] Furthermore, when determining the adjustment factor for the output power of the power battery based on the historical adjustment set, or otherwise, when determining the adjustment factor for the output power of the power battery based on the historical adjustment set and the power adjustment model, the process includes:

[0028] When determining the adjustment factor for the output power of the power battery based on the historical adjustment set, if the historical change difference is unique, the historical adjustment factor corresponding to the historical change difference is used as the adjustment factor for the output power of the power battery; if the historical change difference is not unique, the average of the historical adjustment factors corresponding to each historical change difference is used as the adjustment factor for the output power of the power battery.

[0029] When determining the adjustment factor of the output power of the power battery based on the historical adjustment set and the power adjustment model, the historical adjustment set is divided into a training set and a test set, and the convolutional neural network model is trained based on the training set and the test set. The power adjustment model is determined according to the training results, and the change difference is substituted into the power adjustment model to determine the adjustment factor of the output power of the power battery.

[0030] The output power is directly proportional to the adjustment factor, which determines the battery capacity of each power battery, and the discharge priority of the power batteries is determined based on the total battery capacity of all power batteries.

[0031] Furthermore, when determining the discharge priority of each power battery based on the total capacity of all power batteries, the following steps are included:

[0032] The battery capacity of each power battery is compared with the battery capacity threshold.

[0033] When the battery capacity of all power batteries is greater than or equal to the battery capacity threshold, the battery capacity of all power batteries is arranged in descending order, and the battery with the largest capacity is discharged.

[0034] When the capacity of a power battery is less than the battery capacity threshold, the discharge of that power battery is stopped, and the remaining power batteries are arranged in descending order of capacity, and the discharge is started from the battery with the largest capacity.

[0035] Furthermore, when determining the discharge priority of each power battery based on the total capacity of all power batteries, the following also applies:

[0036] The power battery that does not adjust the output power is called the initial power battery, and the power battery that adjusts the output power is called the adjusted power battery.

[0037] The adjusted capacity of the power battery is recorded as the adjusted capacity, and the initial capacity of the power battery is recorded as the initial capacity.

[0038] When the adjusted capacity and the initial capacity are greater than or equal to the battery capacity threshold, the adjusted capacity and the initial capacity are arranged in descending order, and the battery is discharged from the largest adjusted capacity or the largest initial capacity.

[0039] When the adjusted capacity or initial capacity is less than the battery capacity threshold, the discharge priority is determined based on the relationship between the adjusted capacity and the initial capacity.

[0040] Furthermore, when determining the discharge priority based on the relationship between the adjusted capacity and the initial capacity, the following steps are included:

[0041] When the adjusted capacity or initial capacity is less than the battery capacity threshold, the discharge of the adjusted power battery or initial power battery is stopped, and the adjusted capacity of the remaining adjusted power battery and the initial capacity of the remaining initial power battery are arranged in descending order.

[0042] If the remaining adjustment capacity and the remaining initial capacity are not equal, then discharge is performed from the largest adjustment capacity or the initial capacity, and the adjustment capacity and the initial capacity are discharged alternately.

[0043] If the remaining adjusted capacity and the remaining initial capacity are equal, the discharge priority is determined based on the relationship between the remaining adjusted capacity and the remaining initial capacity.

[0044] Furthermore, if the remaining adjusted capacity and the remaining initial capacity are equal, the discharge priority is determined based on the relationship between the remaining adjusted capacity and the remaining initial capacity, including:

[0045] If the remaining adjusted capacity and the remaining initial capacity are equal, then discharge is performed from the largest initial capacity to the smallest initial capacity until the initial power battery is no longer present, and then discharge is performed with the remaining largest adjusted capacity.

[0046] Compared with existing technologies, the beneficial effects of this invention are as follows: By coordinating the auxiliary daily-use module and the control module, the ineffective power consumption of pure electric port-operated tugboats during docking or anchoring is avoided, thereby increasing the vessel's cruising range and providing strong support for the electrification of tugboats. Furthermore, the auxiliary daily-use module connects the power battery pack to the AC power distribution board, avoiding the intermediate link of the DC power distribution board, thereby reducing the failure factors of pure electric port-operated tugboats, and further reducing the usage time of DC power distribution and related auxiliary equipment, improving the reliability and efficiency of the system. Secondly, the auxiliary daily-use module provides low-power power supply when the vessel is waiting, and the control module determines the discharge priority of each power battery in the power battery pack based on the power battery's charge status, realizing resource management and protection, ensuring the controllability of the power battery pack, thereby avoiding the short-board effect of the power battery, thus optimizing the range of pure electric port-operated tugboats and improving the system's efficiency and stability. Attached Figure Description

[0047] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0048] Figure 1 A schematic diagram of a power system suitable for a pure electric port tugboat provided in an embodiment of the present invention;

[0049] Figure 2 This is a partial schematic diagram of an auxiliary daily-use module provided in an embodiment of the present invention.

[0050] In the diagram: 1. Power battery; 2. DC power distribution board; 3. AC power distribution board; 4. Auxiliary daily use module; 5. Charging box; 20. DC converter; 21. Daily use inverter; 22. Main drive inverter; 23. Main drive motor; 30. Daily use transformer; 40. Auxiliary daily use inverter; 41. Auxiliary sine filter; 42. Auxiliary daily use transformer. Detailed Implementation

[0051] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0052] See Figure 1-2 As shown in some embodiments of this application, a power system suitable for a pure electric port tugboat includes: a power battery pack, a DC power distribution board 2, an AC power distribution board 3, an auxiliary day-use module 4, a charging box 5, and a control module. The power battery pack is connected to the DC power distribution board 2, the auxiliary day-use module 4, and the charging box 5. The charging box 5 is used to charge the power battery pack. The power battery pack includes several power batteries 1, each power battery 1 being used to provide electrical energy. The DC power distribution board 2 is connected to the AC power distribution board 3 and the auxiliary day-use module 4. The DC power distribution board 2 includes several DC converters 20, a day-use inverter 21, and a main drive inverter 22. The several DC converters 20 are connected to the day-use inverter 21 and the main drive inverter 22. The AC power distribution... Board 3 includes several daily-use transformers 30. The auxiliary daily-use module 4 includes an auxiliary daily-use inverter 40, an auxiliary sine filter 41, and an auxiliary daily-use transformer 42. One end of the auxiliary sine filter 41 is connected to the auxiliary daily-use inverter 40, and the other end of the auxiliary sine filter 41 is connected to the auxiliary daily-use transformer 42. The control module is connected to the power battery pack, DC power distribution board 2, AC power distribution board 3, and auxiliary daily-use module 4. The control module is used to switch the power supply mode of the power battery pack according to the ship's status, control the working status of DC power distribution board 2, AC power distribution board 3, and auxiliary daily-use module 4 based on the switched power supply mode, and determine the discharge priority of each power battery 1 based on the charge status of each power battery 1 in the power battery pack.

[0053] In some embodiments of this application, the power system suitable for pure electric port tugboats further includes: each main propulsion inverter 22 connected to the main propulsion motor 23.

[0054] Specifically, the power battery pack consists of eight power batteries 1, each of which can be flexibly charged and discharged. The DC power distribution board 2 serves as the core power distribution hub of the system, regulating the voltage through DC converters 20 and connecting to the main propulsion inverter 22. The main propulsion inverter 22 uses the electrical energy from the power batteries 1 to drive the main propulsion motor 23 and the daytime inverter 21, which in turn supplies power to the AC power distribution board 3. The AC power distribution board 3 is used to distribute AC power to the ship's daytime equipment such as lighting, air conditioning, and pumps and valves. The DC power distribution board 2 is liquid-cooled and is cooled during operation by auxiliary equipment such as cooling water pumps and cooling fans. The DC power distribution board 2 includes eight DC converters 20, two daytime inverters 21, and two main propulsion inverters 22. Each DC converter 20 is connected to one power battery 1, and the main propulsion inverter 22 is connected to the main propulsion motor 23, which provides power to the all-electric harbor tugboat. The AC distribution board 3 includes four daily power transformers 30. The auxiliary daily power module 4 includes an auxiliary daily power inverter 40, an auxiliary sine filter 41, and an auxiliary daily power transformer 42. The auxiliary daily power module 4 is used to independently provide power for daily use. The auxiliary daily power inverter 40 inverts DC power into AC power. The auxiliary sine filter 41 is used to filter out harmonics to ensure power quality and thus avoid interference to daily equipment. The auxiliary daily power transformer 42 is used to adjust the voltage to match the rated voltage and finally supply power to the AC distribution board 3, thereby avoiding the direct operation of the DC distribution board 2. The auxiliary daily use module 4 adopts an air-cooled cooling method, which is different from the inverter method through the DC power distribution board 2. It requires less heat dissipation power and does not need to start the water cooling system of the auxiliary equipment during operation, thereby reducing unnecessary auxiliary equipment startup, reducing the power consumption and noise of the pure electric port tugboat, and improving the stability and reliability of the pure electric port tugboat. The charging box 5 provides a charging source for the power battery pack. The control module is responsible for judging the ship's operating conditions and switching the power supply mode. At the same time, it monitors the charge and health status of each power battery 1 in real time to schedule the power battery 1 with an appropriate charge to discharge, avoiding over-discharge or forced output of the power battery 1 with a low charge, thereby balancing the loss of the power battery 1 to maintain the voltage stability of the power battery pack, and thus ensuring the power supply reliability of the system.

[0055] Understandably, by controlling the ship's operating conditions and switching power supply modes through the control module, the continuous operation of the DC power distribution board 2 is avoided, thus preventing redundant energy consumption due to excessive power consumption. Furthermore, the auxiliary daily utility module 4 is independently powered with a low-power architecture. The combined power consumption of the auxiliary daily utility inverter 40, auxiliary sine filter 41, and auxiliary daily utility transformer 42 is lower than the total operating power of the DC power distribution board 2, thereby increasing the standby time of the pure electric port tugboat. The auxiliary sine filter 41 of the auxiliary daily utility module 4 optimizes power quality, reduces the impact of harmonics on the system, and further improves the system reliability. When waiting for a pure electric tugboat, excessive discharge or forced output of individual power batteries 1 can shorten the lifespan of the power battery pack (forced discharge of power battery 1 will accelerate the sulfation of the plates). The control module judges the ship's operating conditions and switches the power supply mode, and determines the discharge priority of each power battery 1 based on the charge state of each power battery 1 in the power battery pack. This balances the charge and discharge cycles of each power battery 1 and avoids the "barrel effect" (the failure of a single power battery 1 drags down the performance of the power battery pack). In this way, the "one-size-fits-all" power supply is transformed into "on-demand" power supply, which improves the stability and efficiency of the power system.

[0056] In some embodiments of this application, when switching the power supply mode of the power battery pack according to the ship's state, and controlling the working state of the DC power distribution board, AC power distribution board, and auxiliary daily use module based on the switched power supply mode, the following is included: when the ship's state is a waiting state, the power supply mode of the power battery pack is a standby power supply mode, in which the power battery pack supplies power to the AC power distribution board, and the DC power distribution board is in a closed state; when the ship's state is an operating state, the power supply mode of the power battery pack is a power supply mode, in which the power battery pack supplies power to the DC power distribution board, and the DC power distribution board is in an open state.

[0057] Specifically, by dynamically determining the vessel status of the pure electric port-operated tugboat, the stability and efficiency of the power system are ensured. The "waiting" state indicates that the pure electric port-operated tugboat is waiting at the dock or anchorage, requiring only low-power daily loads such as lighting, air conditioning, and pumps / valve operation. In this waiting state, the power battery pack switches to standby mode, bypassing the DC power distribution board and directly supplying power through the auxiliary daily modules. This allows the auxiliary daily transformer to be connected to the AC power distribution board with the correct voltage. Simultaneously, the DC power distribution board is completely shut down, and all auxiliary equipment connected to it can be turned off. This reduces the usage time and lifespan of auxiliary equipment, while also reducing power loss, thereby improving the energy efficiency of the pure electric port-operated tugboat and increasing its cruising range. The operational status indicates that the pure electric port tugboat is performing towing and steering operations. The power battery pack sets its power supply mode to power supply mode, the DC converter is responsible for voltage regulation, and the main propulsion inverter drives the main propulsion motor. During operation, the DC distribution board is activated, the power battery pack connects to the DC distribution board and controls the battery discharge current, gradually balancing the remaining capacity of each battery, thereby eliminating the bottleneck effect, optimizing the remaining range of the entire vessel, ensuring synchronous response between power output and daily load, and achieving on-demand power supply. The DC distribution board contains high-power devices (main propulsion inverter), which generate a lot of waste heat during continuous operation. By switching the power supply mode of the power battery pack, the power circuit of the DC distribution board is cut off, reducing the heat source. Meanwhile, the auxiliary daily operation modules themselves have low power consumption, further ensuring the energy-saving and reliable synergistic optimization of the power system, thereby improving the system's stability and efficiency.

[0058] In some embodiments of this application, when determining the discharge priority of each power battery based on the state of charge of each power battery in the power battery pack, the method includes: when the power supply mode of the power battery pack is determined to be standby power supply mode or power supply mode, obtaining the change value of the charge of each power battery within a unit time and determining the historical average change value of the charge; when the change value of the charge of all power batteries within a unit time is less than or equal to the historical average change value of the charge, it is determined that the output power of the power battery will not be adjusted; and determining the discharge priority of each power battery according to the battery capacity of each power battery; when the change value of the charge of a power battery within a unit time is greater than the historical average change value of the charge, it is determined that the output power of that power battery will be adjusted.

[0059] Specifically, once the power supply mode (standby power supply mode / power supply mode) is determined, the power change value of each power battery per unit time is collected in real time. The power change value reflects the actual discharge rate of the power battery. It is compared with the historical average power change value, which reflects the normal discharge fluctuation range of the power battery. Using the historical average power change value as a benchmark, if the power change value of all power batteries is less than or equal to the historical average power change value, it indicates that the discharge state of the power battery pack is relatively stable. At this time, the discharge priority is allocated according to the battery capacity of each power battery to avoid accelerated wear and tear of small-capacity power batteries due to frequent charging and discharging. If the power change value of a power battery is greater than the historical average power change value, it indicates that the power battery has a discharge abnormality (such as a sudden increase in current due to a change in internal resistance). In this case, the output power of the power battery needs to be adjusted to reduce the discharge current or suspend the output to prevent risks such as over-discharge and thermal runaway. This ensures the energy utilization of the power battery pack under stable operating conditions and the protection of the power battery under abnormal operating conditions, thereby improving the stability and efficiency of the system.

[0060] In some embodiments of this application, when determining to adjust the output power of the power battery, the process includes: determining the difference between the change in the power battery's charge and the historical average change in charge, and comparing the difference with a historical adjustment set. The historical adjustment set includes several historical difference values ​​and several historical adjustment factors, and each historical difference value corresponds to a historical adjustment factor. If there is a historical difference value in the historical adjustment set that is equal to the difference value, then the adjustment factor for the output power of the power battery is determined based on the historical adjustment set; otherwise, the adjustment factor for the output power of the power battery is determined based on the historical adjustment set and the power adjustment model.

[0061] In some embodiments of this application, when determining the adjustment factor of the power battery's output power based on a historical adjustment set, or otherwise determining the adjustment factor of the power battery's output power based on a historical adjustment set and a power adjustment model, the process includes: when determining the adjustment factor of the power battery's output power based on a historical adjustment set, if equal historical change differences are unique, then the historical adjustment factor corresponding to the historical change difference is used as the adjustment factor of the power battery's output power; if equal historical change differences are not unique, then the average of the historical adjustment factors corresponding to each historical change difference is used as the adjustment factor of the power battery's output power. When determining the adjustment factor of the power battery's output power based on a historical adjustment set and a power adjustment model, the historical adjustment set is divided into a training set and a test set, and a convolutional neural network model is trained based on the training set and the test set. The power adjustment model is determined according to the training results, and the change differences are substituted into the power adjustment model to determine the adjustment factor of the power battery's output power. The output power and the adjustment factor are directly proportional. The battery capacity of each power battery is determined, and the discharge priority of each power battery is determined according to the battery capacity of all power batteries.

[0062] Specifically, using the change difference as a judgment benchmark improves the system's intelligence and stability. By judging the degree of matching between the current change difference and historical conditions, when matching historical data is found, this data can be directly used to determine the adjustment factor of the power battery's output power, thus ensuring the reliability and consistency of the adjustment operation. The comprehensive use of a large amount of historical data provides rich reference information for determining the adjustment factor. For cases where the current conditions do not perfectly match historical data, the adjustment factor of the power battery's output power is determined based on the historical adjustment set and the power adjustment model, improving the system's automation level and adjustment accuracy. The historical adjustment set is divided into a training set and a test set; typically, 80%-90% of the data is used as the training set, and the remainder as the test set. To improve the model's generalization ability, both the training and test sets contain diverse data. The convolutional neural network (CNN) model is trained using these sets, with the training set used to train the model and the test set used to evaluate its performance. The CNN model comprises multiple layers of neurons of different types and activation functions, designed to capture complex relationships in the data. During training, the CNN model attempts to learn patterns and relationships in the data to improve its prediction or classification capabilities. The test set data is then input into the trained CNN model to determine its accuracy. Accuracy reflects the model's performance on unknown data and is a crucial performance indicator. Once the model reaches a predetermined accuracy threshold, it is considered to have achieved a stable prediction level. At this point, the trained CNN model is used as a power adjustment model. This model can accurately output the adjustment factor for the power battery's output power, improving the system's stability and reliability.

[0063] It is understandable that the output power is directly proportional to the adjustment factor. Assuming the output power is P and the adjustment factor is H, the adjusted output power is P*H. When it is necessary to reduce the output power, the output power is adjusted according to the adjustment factor to reduce the discharge current or suspend the output, preventing risks such as over-discharge and thermal runaway. This ensures both the energy utilization of the power battery pack under stable operating conditions and the protection of the power battery under abnormal operating conditions. The discharge priority of each power battery is determined according to the battery capacity of all power batteries, avoiding the same treatment of power batteries that may have abnormal discharge as power batteries that are discharging normally, thus ensuring the stability and reliability of the system.

[0064] In some embodiments of this application, when determining the discharge priority of each power battery based on the total capacity of all power batteries, the method includes: comparing the capacity of each power battery with a battery capacity threshold; when the capacity of all power batteries is greater than or equal to the battery capacity threshold, arranging the capacity of all power batteries in descending order and discharging from the largest capacity; when there is a power battery whose capacity is less than the battery capacity threshold, stopping the discharge of that power battery, arranging the remaining power batteries in descending order and discharging from the largest capacity.

[0065] Specifically, refined management of power batteries is achieved through battery capacity threshold screening and graded discharge. A healthy discharge range is defined by battery capacity thresholds, preventing low-capacity power batteries from aging faster during charge-discharge cycles due to insufficient remaining energy and low discharge margin. When all power batteries meet their capacity thresholds, larger-capacity batteries are prioritized for discharge, leveraging their ample energy reserves and more stable voltage during discharge to reduce the frequency of use of smaller-capacity batteries and balance the losses across all power batteries. If any power battery falls below its capacity threshold, its discharge is immediately stopped to prevent voltage drops and current fluctuations caused by insufficient capacity from interfering with the system's power supply. The remaining large-capacity power batteries continue to output power in sequence to ensure continuous power supply. By preventing losses from low-capacity power batteries and prioritizing high-capacity power batteries, the lifespan of each power battery and the consistency of the entire battery pack are extended, the impact of voltage fluctuations on power and daily loads is reduced, and the reliability of power supply is improved.

[0066] In some embodiments of this application, when determining the discharge priority of each power battery based on the battery capacity of all power batteries, the method further includes: designating power batteries whose output power is not adjusted as initial power batteries, designating power batteries whose output power is adjusted as adjusted power batteries, designating the battery capacity of the adjusted power batteries as adjusted capacity, and designating the battery capacity of the initial power batteries as initial capacity; when the adjusted capacity and the initial capacity are greater than or equal to the battery capacity threshold, the adjusted capacity and the initial capacity are arranged in descending order, and discharge is performed starting from the largest adjusted capacity or the initial capacity; when there is an adjusted capacity or the initial capacity that is less than the battery capacity threshold, the discharge priority is determined based on the relationship between the adjusted capacity and the initial capacity.

[0067] In some embodiments of this application, when determining the discharge priority based on the relationship between the adjusted capacity and the initial capacity, the following steps are included: when the adjusted capacity or the initial capacity is less than the battery capacity threshold, the discharge of the adjusted power battery or the initial power battery is stopped, and the adjusted capacity of the remaining adjusted power battery and the initial capacity of the remaining initial power battery are arranged in descending order; if the remaining adjusted capacity and the remaining initial capacity are not equal, the discharge is started from the largest adjusted capacity or the initial capacity, and the adjusted capacity and the initial capacity are discharged alternately; if the remaining adjusted capacity and the remaining initial capacity are equal, the discharge priority is determined according to the relationship between the remaining adjusted capacity and the remaining initial capacity.

[0068] Specifically, the initial power battery (normal discharge) and the adjusted power battery (output power adjusted) are first labeled. This identifies the state differences of each power battery while preserving the usability of the adjusted power battery. The capacity of the adjusted power battery can still support power supply; it is not completely failed, but its output power is adjusted due to abnormal instantaneous changes in charge (such as temporary protection caused by short-term load fluctuations). Directly shutting it down would leave this energy idle, especially during waiting periods between operations, which rely on the power battery's endurance. Furthermore, although the initial power battery is stable, if it is subjected to discharge tasks alone for a long time, it will age faster due to high-frequency, high-load cycles (such as accelerated expansion and contraction of electrode material lattice). If the adjusted power battery is left idle for a long time, electrolyte stratification and passivation of active materials may occur due to stagnation, which would shorten its lifespan. By screening the battery capacity threshold, the discharge of either the adjusted or initial power battery can be effectively stopped to avoid damage from over-discharge. When the initial capacity is greater than or equal to the battery capacity threshold, the adjusted capacity and initial capacity are arranged in descending order, and discharge is performed from the largest adjusted capacity or initial capacity, ensuring the stability and continuity of power supply. When the adjusted capacity or initial capacity is less than the battery capacity threshold, the adjusted capacity of the remaining adjusted power battery and the initial capacity of the remaining initial power battery are arranged in descending order, and priority is given to their use. Then, an alternating discharge mechanism is introduced, allowing the adjusted power battery and the initial power battery to discharge in turn. When used alternately, the adjusted power battery and the initial power battery can complement each other. The initial power battery provides a stable load, and the adjusted power battery can appropriately supplement the load after adjustment due to possible abnormal discharge. This not only avoids the pressure overload of a single battery, but also buffers load changes through dynamic switching to reduce voltage and current surges, thereby maximizing the energy potential of each power battery to improve the overall range and providing stable power support for the pure electric port tugboat.

[0069] In some embodiments of this application, when the remaining adjusted capacity and the remaining initial capacity are equal, the discharge priority is determined based on the relationship between the remaining adjusted capacity and the remaining initial capacity, including: when the remaining adjusted capacity and the remaining initial capacity are equal, the discharge is performed from the largest initial capacity to the smallest initial capacity until there is no initial power battery, and the discharge is performed with the largest remaining adjusted capacity.

[0070] Specifically, when the remaining adjusted capacity is equal to the initial capacity, the initial power battery (normal discharge) is given priority in discharge. When there is no initial power battery with a capacity greater than or equal to the battery capacity threshold, the adjusted power battery is used for discharge. The initial power battery has not experienced any discharge abnormalities, and its internal resistance and voltage curve are relatively stable. It is not prone to fluctuations during discharge and can provide reliable power support for the ship's equipment. Prioritizing the consumption of the initial power battery can reduce the frequency of use of the adjusted power battery. The adjusted power battery may have its output power adjusted due to possible abnormalities. Excessive use may aggravate its internal losses (such as plate reaction imbalance). Delaying its use can provide it with a certain buffer recovery period, thereby slowing down the aging rate and ensuring the reliability and stability of energy distribution. Whether it is alternating discharge or sequential discharge followed by activation of the adjusted power battery, the goal is to maximize the energy potential of each power battery to improve the overall range and provide stable power support for pure electric port tugboats.

[0071] In summary, the beneficial effects of this invention are as follows: By coordinating the auxiliary daily-use module and the control module, the ineffective power consumption of pure electric port-operated tugboats during berthing or anchoring is avoided, thereby increasing the vessel's cruising range and providing strong support for the electrification of tugboats. Furthermore, the auxiliary daily-use module connects the power battery pack to the AC power distribution board, avoiding the intermediate link of the DC power distribution board, thus reducing the failure factors of pure electric port-operated tugboats, thereby reducing the usage time of DC power distribution and related auxiliary equipment, and improving the reliability and efficiency of the system. Secondly, the auxiliary daily-use module provides low-power power supply when the vessel is waiting, and the control module determines the discharge priority of each power battery in the power battery pack based on the power battery's charge status, realizing resource management and protection, ensuring the controllability of the power battery pack, thereby avoiding the bottleneck effect of the power battery, optimizing the range of pure electric port-operated tugboats, and improving the system's efficiency and stability.

[0072] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0073] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0074] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0075] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A power system suitable for pure electric port tugboats, characterized in that, include: Power battery pack, DC power distribution board, AC power distribution board, auxiliary daily use module, charging box and control module; The power battery pack is connected to the DC power distribution board, the auxiliary daily use module and the charging box; The charging box is used to charge the power battery pack, which includes a plurality of power batteries, each of which is used to provide electrical energy. The DC power distribution board is connected to the AC power distribution board and the auxiliary daily use module; The DC power distribution board includes several DC converters, a day-use inverter, and a main drive inverter, with the several DC converters connected to the day-use inverter and the main drive inverter; The AC distribution board includes several day-use transformers; The auxiliary daily use module includes an auxiliary daily use inverter, an auxiliary sine filter, and an auxiliary daily use transformer. One end of the auxiliary sine filter is connected to the auxiliary daily use inverter, and the other end of the auxiliary sine filter is connected to the auxiliary daily use transformer. The control module is connected to the power battery pack, DC power distribution board, AC power distribution board and auxiliary daily use module. The control module is used to switch the power supply mode of the power battery pack according to the ship's status, control the working status of the DC power distribution board, AC power distribution board and auxiliary daily use module based on the switched power supply mode, and determine the discharge priority of each power battery based on the charge status of each power battery in the power battery pack.

2. The power system for pure electric port tugboats according to claim 1, characterized in that, Also includes: Each of the aforementioned main drive inverters is connected to the main drive motor.

3. The power system for pure electric port tugboats according to claim 2, characterized in that, When switching the power supply mode of the power battery pack according to the ship's status, and controlling the operating status of the DC power distribution board, AC power distribution board, and auxiliary daily use module based on the switched power supply mode, the following is included: When the ship is in a waiting state, the power supply mode of the power battery pack is a standby power supply mode. In the standby power supply mode, the power battery pack supplies power to the AC power distribution board, and the DC power distribution board is in a closed state. When the vessel is in operation, the power supply mode of the power battery pack is the power supply mode, in which the power battery pack supplies power to the DC power distribution board, and the DC power distribution board is in the open state.

4. The power system for pure electric port tugboats according to claim 3, characterized in that, Determining the discharge priority of each power battery based on its state of charge in the power battery pack includes: When the power supply mode of the power battery pack is determined to be standby power supply mode or power supply mode, the power change value of each power battery per unit time is obtained, and the historical average power change value is determined. When the change in charge of all power batteries within the unit time is less than or equal to the historical average change in charge, it is determined that the output power of the power batteries will not be adjusted, and the discharge priority of each power battery is determined according to the battery capacity of each power battery. If the change in the power battery charge within a unit of time is greater than the historical average change in charge charge, then it is determined that the output power of the power battery should be adjusted.

5. The power system for pure electric port tugboats according to claim 4, characterized in that, When determining whether to adjust the output power of the power battery, the following should be included: Determine the difference between the change in the power battery's charge and the historical average change in charge, and compare the difference with the historical adjustment set; The historical adjustment set includes several historical change differences and several historical adjustment factors, and each historical change difference corresponds to a historical adjustment factor. If the historical adjustment set contains a historical change difference equal to the change difference, then the adjustment factor for the output power of the power battery is determined based on the historical adjustment set; otherwise, the adjustment factor for the output power of the power battery is determined based on the historical adjustment set and the power adjustment model.

6. The power system for pure electric port tugboats according to claim 5, characterized in that, When determining the adjustment factor for the output power of the power battery based on the historical adjustment set, or otherwise, when determining the adjustment factor for the output power of the power battery based on the historical adjustment set and the power adjustment model, the process includes: When determining the adjustment factor for the output power of the power battery based on the historical adjustment set, if the historical change difference is unique, the historical adjustment factor corresponding to the historical change difference is used as the adjustment factor for the output power of the power battery; if the historical change difference is not unique, the average of the historical adjustment factors corresponding to each historical change difference is used as the adjustment factor for the output power of the power battery. When determining the adjustment factor of the output power of the power battery based on the historical adjustment set and the power adjustment model, the historical adjustment set is divided into a training set and a test set, and the convolutional neural network model is trained based on the training set and the test set. The power adjustment model is determined according to the training results, and the change difference is substituted into the power adjustment model to determine the adjustment factor of the output power of the power battery. The output power is directly proportional to the adjustment factor, which determines the battery capacity of each power battery, and the discharge priority of the power batteries is determined based on the total battery capacity of all power batteries.

7. The power system for pure electric port tugboats according to claim 6, characterized in that, When determining the discharge priority of each power battery based on the total capacity of all power batteries, the following is included: The battery capacity of each power battery is compared with the battery capacity threshold. When the battery capacity of all power batteries is greater than or equal to the battery capacity threshold, the battery capacity of all power batteries is arranged in descending order, and the battery with the largest capacity is discharged. When the capacity of a power battery is less than the battery capacity threshold, the discharge of that power battery is stopped, and the remaining power batteries are arranged in descending order of capacity, and the discharge is started from the battery with the largest capacity.

8. The power system for pure electric port tugboats according to claim 7, characterized in that, When determining the discharge priority of each power battery based on the total capacity of all power batteries, the following also applies: The power battery that does not adjust the output power is called the initial power battery, and the power battery that adjusts the output power is called the adjusted power battery. The adjusted capacity of the power battery is recorded as the adjusted capacity, and the initial capacity of the power battery is recorded as the initial capacity. When the adjusted capacity and the initial capacity are greater than or equal to the battery capacity threshold, the adjusted capacity and the initial capacity are arranged in descending order, and the battery is discharged from the largest adjusted capacity or the largest initial capacity. When the adjusted capacity or initial capacity is less than the battery capacity threshold, the discharge priority is determined based on the relationship between the adjusted capacity and the initial capacity.

9. The power system for pure electric port tugboats according to claim 8, characterized in that, When determining discharge priority based on the relationship between the adjusted capacity and the initial capacity, the following is included: When the adjusted capacity or initial capacity is less than the battery capacity threshold, the discharge of the adjusted power battery or initial power battery is stopped, and the adjusted capacity of the remaining adjusted power battery and the initial capacity of the remaining initial power battery are arranged in descending order. If the remaining adjustment capacity and the remaining initial capacity are not equal, then discharge is performed from the largest adjustment capacity or the initial capacity, and the adjustment capacity and the initial capacity are discharged alternately. If the remaining adjusted capacity and the remaining initial capacity are equal, the discharge priority is determined based on the relationship between the remaining adjusted capacity and the remaining initial capacity.

10. The power system for a pure electric port tugboat according to claim 9, characterized in that, If the remaining adjusted capacity and the remaining initial capacity are equal, the discharge priority is determined based on the relationship between the remaining adjusted capacity and the remaining initial capacity, including: If the remaining adjusted capacity and the remaining initial capacity are equal, then discharge is performed from the largest initial capacity to the smallest initial capacity until the initial power battery is no longer present, and then discharge is performed with the remaining largest adjusted capacity.

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