Method for managing hybrid propulsion system of ship

Abstract

The invention provides a ship hybrid power propulsion system management method. The ship hybrid power propulsion system comprises generator sets used for supplying power to loads and a lithium battery pack, the lithium battery pack is further used for storing electric energy, and the method comprises the steps that system adjusting information is obtained, and the system adjusting information comprises at least one of the remaining electric quantity of the lithium battery pack, the load power and the number of the generator sets; if it is determined that the system adjustment information meets the preset condition, the working state of the system is adjusted according to the met preset condition, and the working state comprises at least one of charging and discharging of the lithium battery pack, increasing and decreasing of the generator set and load unloading. Working states such as charging and discharging of the lithium battery pack and increasing and decreasing of the generator set can be automatically adjusted according to the system adjusting information, system faults are effectively avoided, the operation cost and the maintenance cost are reduced, the advantages of a hybrid power system can be fully played, the energy utilization efficiency is improved, and the adaptability to various working conditions of ships is improved.

Description

Technical Field

[0001] The present application relates to the technical field of ship power management, and specifically, to a method for managing a ship hybrid propulsion system. Background Art

[0002] As an important means of transportation, energy conservation and emission reduction of ship power systems have always been the focus of the industry. Traditional ship power systems mainly use diesel engines or other fossil fuel generators as power sources, which have problems such as low energy efficiency, high pollutant emissions, high operating costs, and high safety hazards. In order to solve the above problems, hybrid power systems have received widespread attention and application in the field of ships in recent years.

[0003] The hybrid power system combines a generator set with a lithium battery pack. This method can fully utilize the high energy density characteristics of fossil fuels used in the generator set and the advantages of easy control and pollution-free electric propulsion, thereby significantly improving energy efficiency and reducing harmful gas emissions. As an auxiliary power source, the lithium battery pack can provide additional power support when the ship needs to accelerate, climb or cope with high-load conditions, ensuring the stability and reliability of power output. In addition, the energy storage function of the lithium battery pack can also recover excess energy when the ship is decelerating, braking or idling, improving overall navigation efficiency and endurance.

[0004] However, existing ship hybrid power systems often adopt energy management strategies and battery charge and discharge control strategies that only use lithium battery packs as backup energy sources or control the charging and discharging of lithium battery packs during fixed time periods. These strategies are not reasonable and can easily cause the generator set or lithium battery pack to be in an overloaded or non-working state for a long time, which can easily cause system failures and increase operating and maintenance costs. It is difficult to fully utilize the advantages of the hybrid power system, the energy utilization efficiency is low, and the adaptability to various ship operating conditions is poor. Summary of the invention

[0005] In view of the shortcomings of existing methods, this application proposes a method for managing a hybrid propulsion system for ships, which can solve the problems that existing strategies are prone to system failures, increase operating costs and maintenance costs, make it difficult to fully utilize the advantages of hybrid power systems, have low energy utilization efficiency, and have poor adaptability to various operating conditions of ships.

[0006] According to one aspect of an embodiment of the present application, an embodiment of the present application provides a method for managing a hybrid propulsion system for a ship, wherein the hybrid propulsion system for the ship includes a generator set and a lithium battery pack for supplying power to a load, and the lithium battery pack is also used to store electrical energy, and the method includes:

[0007] Acquiring system adjustment information, wherein the system adjustment information includes at least one of the remaining power of the lithium battery pack, the load power, and the number of generator sets;

[0008] If it is determined that the system adjustment information meets the preset conditions, the working state of the system is adjusted according to the preset conditions met, and the working state includes at least one of charging and discharging of the lithium battery pack, increasing and decreasing of the generator set, and load unloading.

[0009] In a possible implementation, the system further includes a DC power distribution module provided with a rectifier, a DC bus, and a bidirectional DC converter, the DC power distribution module is connected to the load, the generator set is connected to the DC bus through the rectifier, the lithium battery pack is connected to the DC bus through the bidirectional DC converter, and the droop characteristic slope of the bidirectional DC converter is smaller than the droop characteristic slope of the rectifier;

[0010] The method comprises:

[0011] Acquiring power change information through the DC bus;

[0012] If it is determined that the power change information satisfies the power change condition, the output voltage or output current of the rectifier and / or the DC voltage set value and current limit of the bidirectional DC converter are adjusted according to the power change information to perform load transfer.

[0013] In a possible implementation, the system adjustment information includes the remaining power of the lithium battery pack, the preset condition includes that the remaining power of the lithium battery pack is within a preset range, and adjusting the working state of the system according to the satisfied preset condition includes:

[0014] If it is determined that the remaining power of the lithium battery pack is within a preset range, the generator set is controlled to operate at a preset load rate, and the charging and discharging of the lithium battery pack is controlled according to the current power demand to perform peak shaving and valley filling. The preset load rate is determined based on the fuel loss of the generator set.

[0015] In a possible implementation, the method includes:

[0016] If it is determined that the remaining power of the lithium battery pack is not within the preset range, the lithium battery pack is controlled to be charged or discharged according to the magnitude between the remaining power and the boundary value of the preset range.

[0017] In a possible implementation, the complexity includes simple, medium, and complex, and the scaling coefficients of the super-resolution models corresponding to different complexities are different. The scaling coefficients are used to adjust the usage ratio of the convolution branch and the self-attention branch.

[0018] In a possible implementation, the system adjustment information includes load power and the number of generator sets, the preset condition includes that the load power increases to a first load preset value and the number of generator sets is less than the first preset value, and adjusting the working state of the system according to the satisfied preset condition includes:

[0019] After waiting for a first time, a first number of backup generators are started.

[0020] In a possible implementation, the preset condition includes that the number of the generator sets is greater than a second preset value and the load power is reduced to a second load power, and adjusting the working state of the system according to the satisfied preset condition includes:

[0021] If it is determined that the remaining power of the lithium battery pack is greater than the first predetermined threshold, then after waiting for a second time, a second number of generator sets are decoupled, and the second number is less than the second preset value;

[0022] If it is determined that the remaining power of the lithium battery pack is less than the first predetermined threshold, the lithium battery pack is charged.

[0023] In a possible implementation, the preset condition includes that all the generator sets are working and the load power increases to a predetermined value, and adjusting the working state of the system according to the satisfied preset condition includes:

[0024] If it is determined that the remaining power is less than a second predetermined threshold, unloading the preset load after waiting for a third time;

[0025] If it is determined that the remaining power is greater than the second predetermined threshold, the lithium battery pack is controlled to discharge, and the preset load is unloaded according to the load power after the lithium battery pack is discharged.

[0026] In a possible implementation, the load includes a continuous load and an intermittent load, and the calculation of the load power includes:

[0027] Obtain the rated input power of each load and determine the continuous load and intermittent load according to the working conditions of the ship;

[0028] determining a demand factor for the load and a simultaneous factor for the intermittent load;

[0029] The load power is calculated according to the rated input power, the demand factor, and the simultaneity factor.

[0030] In a possible implementation, the calculating the load power according to the rated input power, the required coefficient, and the simultaneous coefficient includes:

[0031] Determine a first required power according to the rated input power, the required coefficient and the simultaneous coefficient;

[0032] A second required power is determined based on the first required power and a grid loss, and the second required power is determined as the load power.

[0033] In a possible implementation manner, determining the first required power according to the rated input power, the required coefficient, and the simultaneous coefficient includes:

[0034] By P G =∑K i ·P ci +K2·∑K j ·P Ij Calculate the first required power, where P G is the first required power, P ci is the rated input power of the i-th continuous load, P Ij is the rated input power of the i-th intermittent load, K i is the required coefficient of the i-th continuous load, K j is the required coefficient of the jth intermittent load, and K2 is the simultaneous coefficient.

[0035] The beneficial technical effects brought about by the technical solution provided by the embodiment of the present application include:

[0036] A ship hybrid propulsion system management method provided by the present application has the beneficial effect of obtaining system adjustment information; if it is determined that the system adjustment information meets the preset conditions, the working state of the system is adjusted according to the preset conditions met, and the working state includes at least one of the charging and discharging of lithium battery packs, the increase and decrease of generator sets, and load unloading. The present application can automatically adjust the working states such as the charging and discharging of lithium battery packs, the increase and decrease of generator sets according to the system adjustment information, effectively avoid the occurrence of system failures, reduce operating costs and maintenance costs, and give full play to the advantages of the hybrid power system, improve energy utilization efficiency, and improve adaptability to various working conditions of ships.

[0037] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0039] Figure 1 A flow chart of a method for managing a hybrid propulsion system for a ship provided in an embodiment of the present application;

[0040] Figure 2 A structural diagram of a hybrid propulsion system for a ship provided in an embodiment of the present application;

[0041] Figure 3 A schematic diagram of the management of a generator set and a lithium battery pack provided in an embodiment of the present application.

[0043] 1. Generator set; 2. Lithium battery pack; 3. DC distribution module; 31. Rectifier; 32. Bidirectional DC converter; 33. DC bus; 34. Inverter unit; 35. Inverter; 41. Transformer module; 42. Propulsion motor; 5. AC distribution module; 51. First bus; 52. Second bus; 53. Third bus; 61. First transformer; 62. Second transformer. DETAILED DESCRIPTION

[0044] The embodiments of the present application are described below in conjunction with the drawings in the present application. It should be understood that the implementation methods described below in conjunction with the drawings are exemplary descriptions for explaining the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions of the embodiments of the present application.

[0045] It will be understood by those skilled in the art that, unless specifically stated, the "said" and "the" used herein may also include plural forms. It should be further understood that the wording "including" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the implementation of other features, information, data, steps, operations, elements, components and / or combinations thereof supported by the present technical field. It should be understood that when we say that an element is "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or it may refer to the connection relationship between the element and the other element through an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein refers to at least one of the items defined by the term, for example, "A and / or B" may be implemented as "A", or as "B", or as "A and B".

[0046] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0047] The embodiment of the present application provides a method for managing a hybrid propulsion system for a ship, which can be used for a hybrid propulsion system for a ship. The hybrid propulsion system for a ship includes a generator set 1 for supplying power to a load and a lithium battery pack 2, and the lithium battery pack 2 is also used to store electrical energy. The hybrid propulsion system for a ship manages the generator set 1, the lithium battery pack 2, and the load in real time through the method.

[0048] In one embodiment, the lithium battery pack 2 can use lithium iron phosphate batteries, the rated capacity of a single battery is 100 ampere hours, a total of 200 strings are configured, each string has 104 cells, and the total capacity is 2080 kWh. The maximum charging power of the lithium battery pack 2 is 200 kilowatts, and the maximum discharge power is 300 kilowatts. The battery pack allows an operating temperature range of -20°C to 55°C.

[0049] In one embodiment, the lithium battery pack 2 can use ternary lithium batteries, the rated capacity of the single battery is 120 ampere hours, a total of 180 strings are configured, each string has 120 cells, and the total capacity is 2592 kWh. The maximum charging power of the lithium battery pack 2 is 300 kilowatts, and the maximum discharge power is 400 kilowatts. The allowable operating temperature range of the lithium battery pack 2 is 0°C to 45°C.

[0050] In one embodiment, the lithium battery pack 2 may use lithium manganese oxide batteries, the rated capacity of a single battery is 150 ampere hours, a total of 160 strings are configured, each string has 128 cells, and the total capacity is 3072 kWh. The maximum charging power of the lithium battery pack 2 is 400 kilowatts, and the maximum discharge power is 500 kilowatts. The allowable operating temperature range of the lithium battery pack 2 is -10°C to 50°C.

[0051] Optionally, the ship hybrid propulsion system may further include a power management system, and the propulsion system may execute the method of the present application through the power management system. The power management system may be provided with a computer, a CPU, and other devices capable of adjusting the working state of the propulsion system according to the system adjustment information, and may also be provided with a communication device connected to the cloud, through which the acquired charging and discharging information is sent to the cloud, and the working state is adjusted according to the feedback information transmitted by the cloud.

[0052] In one embodiment, Figure 3 As shown, the power management system may include a control main station and a PMS (Power Management System) human-machine interface. The control main station is connected to the PMS human-machine interface. After obtaining the system adjustment information, the control main station can control the working state of the propulsion system according to the system adjustment information, and can display the current working state of the propulsion system in real time through the PMS human-machine interface and obtain the control instructions input by the user.

[0053] like Figure 1-Figure 3 As shown, the ship hybrid propulsion system management method of the present application includes:

[0054] S101: Obtain system adjustment information.

[0055] Optionally, the system adjustment information includes at least one of the remaining power of the lithium battery group 2, the load power, and the number of the generator sets 1.

[0056] Optionally, the ship hybrid propulsion system may be provided with a plurality of sensors for collecting system adjustment information, and the sensors may be arranged in the lithium battery pack 2, the generator set 1 and the current transmission line of the system. The setting position of the sensor may be set according to the type of information collected, the location of the collected object and other information.

[0057] Optionally, it is possible to detect whether the propulsion system is currently working, and if it is determined that the system has started working, the system adjustment information is collected. It is also possible to detect whether the information collection conditions are currently met, and if it is determined that the information collection conditions are met, the system adjustment information is collected. The information collection conditions may include at least one of the following conditions: receiving an information collection instruction, the current ship is in a preset working mode, and the lithium battery pack 2 is working normally.

[0058] Optionally, the propulsion system may also include a DC distribution module 3 provided with a rectifier 31 (AC / DC), a DC bus 33, and a bidirectional DC converter 32 (DC / DC), the DC distribution module 3 is connected to the load, the generator set 1 is connected to the DC bus 33 through the rectifier 31, the lithium battery pack 2 is connected to the DC bus 33 through the bidirectional DC converter 32, and the droop characteristic slope of the bidirectional DC converter 32 is smaller than the droop characteristic slope of the rectifier 31.

[0059] Optionally, the droop characteristic slope of the bidirectional DC converter 32 can be controlled based on the voltage mode of the DC bus 33. The bidirectional DC converter 32 undertakes the energy regulation task in the propulsion system and needs to have a wider regulation range and higher regulation accuracy. By setting a smaller droop characteristic slope, the output voltage of the bidirectional DC converter 32 can change more smoothly when the output power changes, which is beneficial to the stable operation of the propulsion system and the precise management of power.

[0060] In one embodiment, Figure 3 As shown, the generator set 1 can be a diesel generator, the number of diesel generators can be 3, the number of lithium battery packs 2 can be 3, each diesel generator is connected to the control main station through a rectifier 31, and the control main station is connected to the lithium battery pack 2 through a bidirectional DC converter 32. Different lithium battery packs 2 are connected to different bidirectional DC converters 32.

[0061] Optionally, the method of the present application further includes: obtaining power change information through the DC bus 33; if it is determined that the power change information satisfies the power change condition, adjusting the output voltage or output current of the rectifier 31 and / or the DC voltage set value and current limit value (such as setting the output current range) of the bidirectional DC converter 32 according to the power change information to perform load transfer. The power change condition may be a sudden increase in power (such as the power increase within a set time period is greater than a first threshold) or a sudden decrease in power (such as the power reduction within a set time period is greater than a second threshold).

[0062] Optionally, the power change information may be the change information of the voltage and / or current of the DC bus 33, or the voltage and current of the DC bus 33 may be collected, and the power of the propulsion system may be calculated by the voltage and current, and then the power change information may be obtained based on the power.

[0063] Optionally, the power change information can be collected through a power management system, and the power management system can further control the power output of the bidirectional DC converter 32 by adjusting the DC voltage set value. This adjustment method can flexibly adjust the working state of the bidirectional DC converter 32 according to the actual needs of the propulsion system, thereby achieving optimal allocation and efficient utilization of energy.

[0064] Optionally, when a sudden increase or decrease in power is detected through the DC bus 33, the bidirectional DC converter 32 may first bear most of the sudden increase or decrease in power (the droop characteristic slope of the bidirectional DC converter 32 is small, and the output voltage changes smoothly), and then the power management system controls the increased or decreased load to be gradually transferred to the rectifier 31. The gradual transfer of the load can be achieved by adjusting the output voltage or current of the rectifier 31 and controlling the connection or disconnection of the load.

[0065] Optionally, after detecting that the power change information meets the power change conditions, the control parameters of the rectifier 31 or the bidirectional DC converter 32 (such as the voltage parameters, current parameters, efficiency parameters of the rectifier 31, the output voltage, output current, ripple, transient response and other parameters of the DC converter) or the operating mode can be adjusted to transfer the load and reduce the impact on the propulsion system.

[0066] In one embodiment, there are two generator sets 1 and two lithium battery packs 2. The power management system uses the DC bus 33 voltage mode to control the rectifier 31 and the bidirectional DC converter 32. The droop characteristic slope of the bidirectional DC converter 32 can be set to 0.8, and the droop characteristic slope of the rectifier 31 is set to 1.2. The power management system controls the power of the bidirectional DC converter 32 by adjusting the DC voltage set value. When the DC bus 33 has a sudden increase or decrease in power, the bidirectional DC converter 32 bears most of the sudden increase or decrease in power, and then the power management system controls the increase or decrease in load to gradually transfer to the rectifier 31. The maximum charging power of the bidirectional DC converter 32 is set to 200 kilowatts, and the maximum discharge power is set to 300 kilowatts.

[0067] In one embodiment, the propulsion system includes two generator sets 1 and two lithium battery packs 2. The power management system adopts the DC bus 33 voltage mode control, the droop characteristic slope of the bidirectional DC converter 32 is set to 0.6, and the droop characteristic slope of the rectifier 31 is set to 1.0. The power management system controls the power of the bidirectional DC converter 32 by adjusting the DC voltage set value. When the DC bus 33 has a sudden increase or decrease in power, the bidirectional DC converter 32 bears most of the sudden increase or decrease in power, and then the power management system controls the increase or decrease in load to gradually transfer to the rectifier 31. The maximum charging power of the bidirectional DC converter 32 is set to 300 kilowatts, and the maximum discharge power is set to 400 kilowatts.

[0068] In one embodiment, the propulsion system includes three generator sets 1 and a lithium battery pack 2. The power management system adopts the DC bus 33 voltage mode control, the droop characteristic slope of the bidirectional DC converter 32 is set to 0.5, and the droop characteristic slope of the rectifier 31 is set to 0.8. The power management system controls the power of the bidirectional DC converter 32 by adjusting the DC voltage set value. When the DC bus 33 has a sudden increase or decrease in power, the bidirectional DC converter 32 bears most of the sudden increase or decrease in power, and then the power management system controls the increase or decrease in load to gradually transfer to the rectifier 31. The maximum charging power of the bidirectional DC converter 32 is set to 400 kilowatts, and the maximum discharge power is set to 500 kilowatts.

[0069] Alternatively, if Figure 2 As shown, the DC power distribution module 3 may also include an inverter unit 34 and an inverter 35, and the propulsion system may also include an AC power distribution module 5, a transformer module 41, a first transformer 61, and a second transformer 62. The inverter unit 34 is connected to the DC bus 33 and the propulsion motor 42 on the ship respectively. The DC power transmitted by the DC bus 33 is converted into AC power by the inverter unit 34 and transmitted to the propulsion motor 42, which includes the bow thruster and the propulsion motor 42 at other positions of the ship. The transformer module 41 is connected to the AC configuration module and the inverter 35 respectively. The inverter 35 can convert DC power into AC power and transmit the converted AC power to the transformer module 41, and can also receive the AC power transmitted by the transformer module 41 and transmit the AC power to the DC bus 33, so as to charge the lithium battery pack 2 through the DC bus 33.

[0070] Optionally, the AC pairing module may include an AC bus and a control switch, which controls the connection between the AC bus and the transformer and the shore power box (equipment for supplying power to the ship). The electric energy transmitted by the shore power box can be transmitted to the lithium battery pack 2 through the AC bus, the transformer module 41 and the inverter 35. The AC bus is connected to the load and the first transformer 61 and the second transformer 62. The AC bus may include a first bus 51, a second bus 52 and a third bus 53, the first bus 51 and the second bus 52 are connected through a control switch, and the first bus 51 is connected to the third bus 53 through the first transformer 61, and the second bus 52 is connected to the third bus 53 through the second transformer 62.

[0071] S102: If it is determined that the system adjustment information meets the preset conditions, the working state of the system is adjusted according to the satisfied preset conditions.

[0072] Optionally, the working state includes at least one of charging and discharging of the lithium battery pack 2, increasing and decreasing of the generator set 1, and load unloading.

[0073] Optionally, the system adjustment information includes the remaining power of the lithium battery pack 2, the preset condition includes that the remaining power of the lithium battery pack 2 is within a preset range, and the working state of the system is adjusted according to the preset condition that is satisfied, including: if it is determined that the remaining power of the lithium battery pack 2 is within the preset range, then the generator set 1 is controlled to operate at a preset load rate, and the charging and discharging of the lithium battery pack 2 is controlled according to the current power demand to perform peak shaving and valley filling, and the preset load rate is determined based on the fuel loss of the generator set 1.

[0074] Optionally, the preset load rate may be a load rate when the fuel loss of the generator set 1 is optimal (when the electrical energy generated by consuming unit fuel is the highest).

[0075] Optionally, the preset range can be 50%-95%. When the remaining power of the lithium battery group 2 is within this range, the lithium battery group 2 is controlled to charge and discharge normally, and the generator set 1 is controlled to operate at a preset load rate. The remaining or insufficient power is provided by the lithium battery group 2, and the lithium battery group 2 achieves peak shaving and valley filling through charging and discharging.

[0076] Optionally, if it is determined that the remaining power of the lithium battery pack 2 is not within a preset range, the lithium battery pack 2 is controlled to be charged or discharged according to the magnitude of the remaining power and a boundary value of the preset range.

[0077] Optionally, if the remaining power of the lithium battery pack 2 is less than the minimum boundary value of the preset range, the lithium battery pack 2 is controlled to charge. If the remaining current of the lithium battery pack 2 is greater than the maximum boundary value of the preset range, the lithium battery pack 2 is controlled to discharge.

[0078] In one embodiment, the propulsion system includes three generator sets 1 and two lithium battery sets 2. The preset range can be 50%-95%. If the remaining power of the lithium battery set 2 is less than 50%, the lithium battery set 2 is controlled to only charge but not discharge. If the remaining power is greater than 95%, the lithium battery set 2 is controlled to only discharge but not charge.

[0079] In one embodiment, the propulsion system includes two generator sets 1 and two lithium battery groups 2. The preset range can be 60%-90%, and the preset load rate can be that the generator set 1 operates at 75% of the rated power. If the remaining power of the lithium battery group 2 is less than 60%, the lithium battery group 2 is controlled to only charge but not discharge. If the remaining power is greater than 90%, the lithium battery group 2 is controlled to only discharge but not charge.

[0080] In one embodiment, the propulsion system includes three generator sets 1 and a lithium battery group 2. The preset range can be 55%-85%. The preset load rate can be that the generator set 1 operates at 70% of the rated power. If the remaining power of the lithium battery group 2 is less than 55%, the lithium battery group 2 is controlled to only charge but not discharge. If the remaining power is greater than 85%, the lithium battery group 2 is controlled to only discharge but not charge.

[0081] Optionally, the system adjustment information includes the load power and the number of generator sets 1, the preset condition includes that the load power increases to a first load preset value and the number of generator sets 1 is less than the first preset value, and the working state of the propulsion system is adjusted according to the preset condition satisfied, including: after waiting for a first time, starting a first number of standby generators. The load power may be the power required to provide for the current load operation. The first preset value may be the total number of generator sets 1.

[0082] In one embodiment, the number of generator sets 1 is 3, the first load preset value may be 85% of the rated power of the ship system, the first preset value may be 5, the first time may be 15 seconds, and the first preset number may be 1. When the number of generator sets 1 powered by electricity is less than 3 and the load power increases to 85% of the rated power, one generator set 1 is automatically started after a delay of 15 seconds.

[0083] Optionally, the preset condition includes that the number of generator sets 1 is greater than a second preset value and the load power is reduced to a second load power, and adjusting the working state of the system according to the preset condition that is satisfied includes: if it is determined that the remaining power of the lithium battery group 2 is greater than a first preset threshold, then after waiting for a second time, de-energizing a second number of generator sets 1, and the second number is less than a second preset value; if it is determined that the remaining power of the lithium battery group 2 is less than the first preset threshold, then charging the lithium battery group 2. The second preset value is less than the first preset value.

[0084] In one embodiment, the number of generator sets 1 is 3, the second preset value may be 1, the second load power may be 30%, the first predetermined threshold may be 95%, and the second time may be 30s. When the number of generator sets 1 supplying power is greater than 1 and the load power is reduced to 30% of the rated power, if the remaining power is greater than 95%, one generator set 1 is automatically de-energized after a delay of 30s, and if the remaining power is less than 95%, the lithium battery pack 2 is charged first.

[0085] In one embodiment, the number of generator sets 1 is 2. When the number of generator sets 1 on the grid is 1 and the load power increases to 90% of the rated power, another generator set 1 is automatically started after a delay of 10 seconds. When the number of generator sets 1 on the grid is 2 and the load power decreases to 25% of the rated power, if the remaining power of the lithium battery group 2 is greater than 90%, one generator set 1 is automatically de-energized after a delay of 20 seconds. If the remaining power of the lithium battery group 2 is less than 90%, the lithium battery group 2 is charged first.

[0086] In one embodiment, the number of generator sets 1 is 3. When the number of generator sets 1 on the grid is less than 3 and the load power increases to 80% of the rated power, another generator set 1 is automatically started after a delay of 20 seconds. When the number of generator sets 1 on the grid is 3 and the load power decreases to 35% of the rated power, if the remaining power of the lithium battery group 2 is greater than 85%, one generator set 1 is automatically de-energized after a delay of 40 seconds. If the remaining power of the lithium battery group 2 is less than 85%, the lithium battery group 2 is charged first.

[0087] Optionally, the preset conditions include that the generator set 1 is fully operational and the load power increases to a predetermined value, and the operating state of the system is adjusted according to the preset conditions that are satisfied, including: if it is determined that the remaining power is less than the second predetermined threshold, then wait for a third time before unloading the preset load; if it is determined that the remaining power is greater than the second predetermined value, then control the lithium battery pack 2 to discharge, and unload the preset load according to the load power after the lithium battery pack 2 is discharged. After the lithium battery pack 2 is discharged, if it is detected that the load power has not been effectively reduced (such as not reduced within the fourth time), the preset load is unloaded.

[0088] Optionally, the preset load may be an air conditioner, an oven, or other non-critical loads that do not affect the navigation of the ship. A trip coil may be provided on the power switch of these loads, and the power switch may be disconnected by the trip coil, thereby achieving rapid unloading of the preset load.

[0089] In one embodiment, the predetermined value may be 90% of the rated power, the number of generator sets 1 is 3, the second predetermined threshold may be 50% of the rated power, and the third time may be 10 seconds. When the number of online generator sets is equal to 3 (and all generator sets 1 are powered) and the load increases to 90% of the rated power, if the remaining power of the lithium battery pack 2 is <50%, the non-critical load is automatically unloaded after a delay of 10 seconds. If the remaining power is >50%, the lithium battery pack 2 is controlled to discharge first (charging has a lower priority than discharging). When the lithium battery pack 2 reaches its set discharge power and the load power is still >90% of the rated power, the non-critical load is automatically unloaded after a delay of 10 seconds.

[0090] In one embodiment, the predetermined value may be 95% of the rated power, the number of generator sets 1 is 2, the second predetermined threshold may be 60% of the rated power, and the third time may be 5 seconds. When the number of online generator sets is equal to 2 (and all generator sets 1 are powered) and the load increases to 95% of the rated power, if the remaining power of the lithium battery pack 2 is <60%, the non-critical load is automatically unloaded after a delay of 5 seconds. If the remaining power is >60%, the lithium battery pack 2 is controlled to discharge first (charging has a lower priority than discharging). When the lithium battery pack 2 reaches its set discharge power and the load power is still >95% of the rated power, the non-critical load is automatically unloaded after a delay of 5 seconds.

[0091] In one embodiment, the predetermined value may be 92% of the rated power, the number of generator sets 1 is 3, the second predetermined threshold may be 55% of the rated power, and the third time may be 15 seconds. When the number of online units is equal to 3 (and all generator sets 1 are powered) and the load increases to 92% of the rated power, if the remaining power of the lithium battery pack 2 is <55%, the non-critical loads such as the air-conditioning distribution box, the kitchen distribution box, and the cab air-conditioning are automatically unloaded after a delay of 15 seconds. If the remaining power is >55%, the lithium battery pack 2 is controlled to discharge first (charging has a lower priority than discharging). When the lithium battery pack 2 reaches its set discharge power and the load power is still >92% of the rated power, the non-critical loads are automatically unloaded after a delay of 15 seconds.

[0092] Optionally, in order to effectively protect and manage the lithium battery pack 2, the propulsion system may also include a battery temperature detection module, a battery voltage detection module, and a battery current detection module. These modules collect the voltage, temperature, current and other parameters of the lithium battery pack 2, and dynamically adjust the battery charging and discharging mode according to the above strategy to improve the utilization efficiency of the lithium battery pack 2.

[0093] Optionally, the calculation of load power can be achieved by using the required coefficient method, three-category load method, day and night load method, probability analysis calculation method, formula calculation method, calculation method based on a certain special heavy load, etc. The selection and use of this calculation method can be determined according to the purpose of the ship.

[0094] Optionally, the load includes continuous load and intermittent load, and the calculation of load power includes: obtaining the rated input power of each load, determining the continuous load and intermittent load according to the operating condition of the ship; determining the required coefficient of the load and the simultaneous coefficient of the intermittent load; and calculating the load power based on the rated input power, the required coefficient and the simultaneous coefficient.

[0095] Optionally, the ship's operating conditions may include information on sailing, port entry and exit, berthing, loading and unloading, etc. Among them, the information corresponding to sailing includes the full-load full-speed sailing state, the information corresponding to port entry and exit includes the low-speed sailing or maneuvering state in the port, the information corresponding to berthing includes the anchoring and mooring state, and sometimes this operating condition is combined with the port entry and exit operating conditions into the port entry and exit operating conditions, the information corresponding to berthing includes the berthing pier or moored ship without passengers or cargo, and the information corresponding to loading and unloading includes the loading and unloading state of cargo ships, liquid cargo ships (oil tankers, liquefied gas ships and chemical ships) or container ships.

[0096] Optionally, the load is an electrical equipment, which includes (1) auxiliary machinery for power plants - auxiliary machinery serving the main engine and main boiler, such as lubricating oil pumps, seawater cooling pumps, fresh water cooling pumps and blowers; (2) deck machinery - including anchor winches, capstans, steering gears, cargo winches, gangways, boat lifts, etc.; (3) cabin auxiliary machinery - including domestic water pumps, fire pumps, bottom pumps and auxiliary machinery serving auxiliary boilers; (4) mechanical repair machinery - including lathes, drilling machines, electric welders and turning machines; (5) refrigeration and ventilation - including air conditioning devices , auxiliary machines and ventilators for food cold storage, etc.; (6) kitchen equipment - including auxiliary machines for kitchen machinery such as electric stoves and electric ovens, and electric tea stoves, etc.; (7) lighting equipment - including lighting equipment such as cabin lighting, cabin lighting, deck lighting, navigation lights, signal lights, and electric fans, etc.; weak current equipment - including radio communication, navigation, crew and ship safety and onboard communication equipment, etc.; (9) automation equipment, etc. - such as automation devices, battery charging equipment, refrigerated containers and bow thrusters, and special equipment for special ships, etc. Among them, the classification of electrical equipment varies greatly depending on the type, tonnage, and main engine type of the ship. When calculating the load power, electrical equipment can be increased, decreased, or combined.

[0097] Optionally, the required coefficient = the maximum required power of the equipment / the rated input power of the equipment * 100%. The rated input power of the equipment, for motors, is its rated input power. For lighting and weak current equipment, the total power of these equipment can be used as the rated power. For equipment whose power fluctuates over time, the average power is generally taken as the rated input power.

[0098] Optionally, the required coefficient varies with the ship's operating conditions. For general commercial ships, the following values ​​can be taken:

[0099] General auxiliary machine: 60% to 95%;

[0100] Servo: 20%~30%;

[0101] Electric heating equipment: 50% to 100%;

[0102] General lighting: 70%~80% (navigation), 60%~70% (loading and unloading), 50%~60% (berthing);

[0103] Working light: 100% (loading and unloading).

[0104] Optionally, when the air conditioner is a split air conditioner, it is an intermittent load, and when the air conditioner is a central air conditioner, it can be a continuous load, and the demand coefficient when the air conditioner is an intermittent load is greater than the demand coefficient when the air conditioner is a continuous load.

[0105] Optionally, each intermittent load will not be used at the same time, so under certain conditions, the sum of the maximum power requirements of each intermittent load that may be operated is smaller than the sum of the maximum power requirements of all intermittent loads.

[0106] Wherein, the simultaneity factor = the sum of the maximum power requirements of all intermittent loads / the sum of the maximum power requirements of all intermittent loads that may operate.

[0107] The value of the simultaneous coefficient varies with the different operating conditions of the ship. The simultaneous coefficient is also affected by the ship's loading status, navigation area and season, and is usually determined based on experience and actual test results. When there is no accurate calculated value, the simultaneous coefficient can be selected as 0.3 to 0.5.

[0108] Optionally, the load power is calculated according to the rated input power, the required coefficient and the simultaneous coefficient, including: determining a first required power according to the rated input power, the required coefficient and the simultaneous coefficient; determining a second required power based on the first required power and grid loss, and determining the second required power as the load power.

[0109] Optionally, determining the first required power according to the rated input power, the required coefficient and the simultaneous coefficient includes: G =∑K i ·P ci +K2·∑K j ·P Ij Calculate the first required power, where P G is the first required power, P ci is the rated input power of the i-th continuous load, P Ij is the rated input power of the i-th intermittent load, K i is the required coefficient of the i-th continuous load, K j is the required coefficient of the jth intermittent load, and K2 is the simultaneous coefficient.

[0110] In one embodiment, the calculation of load power may include: calculating the rated input power of each electrical device. Determining the electrical devices required for use under each operating condition, thereby identifying continuous loads and intermittent loads. Determining the required coefficient of each electrical device. Calculating the required power of each electrical device, and calculating the total power required for each electrical device under each operating condition. Determining the simultaneous coefficient of the intermittent load, and calculating the first required power. When calculating the first required power, if there is a larger load in the intermittent load, the sum of the power required for the continuous load (∑K i ·P ci ) plus the maximum intermittent load power required (∑K j ·P Ij ) plus the sum of the power required by other intermittent loads (K2·∑K (j-1) ·P I(j-1) ), and the addition result is determined as the first required power. After the first required power is calculated, the first required power is added to the grid loss to obtain the second required power, and the grid loss can be 5% of the first required power.

[0111] Optionally, after calculating the load power under normal conditions of the ship, the capacity and number of generator sets 1 can be determined based on the load power, and the load rate of the generator set 1 under various operating conditions of the ship (the ratio of the load power under various operating conditions to the total rated power of the generator set 1) can be calculated, and the charging and discharging of the lithium battery group 2 under different operating conditions can be controlled based on the load rate.

[0112] The ship hybrid propulsion system management method of the present application obtains system adjustment information; if it is determined that the system adjustment information meets the preset conditions, the working state of the system is adjusted according to the preset conditions that are met, and the working state includes at least one of the charging and discharging of the lithium battery pack, the increase and decrease of the generator set, and the load unloading. The present application can automatically adjust the working states such as the charging and discharging of the lithium battery pack, the increase and decrease of the generator set according to the system adjustment information, effectively avoid the occurrence of system failures, reduce operating costs and maintenance costs, and give full play to the advantages of the hybrid power system, improve energy utilization efficiency, and improve adaptability to various working conditions of the ship.

[0113] Those skilled in the art will appreciate that the various operations, methods, steps, measures, and schemes in the processes discussed in this application may be alternated, changed, combined, or deleted. Furthermore, other steps, measures, and schemes in the various operations, methods, and processes discussed in this application may also be alternated, changed, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and schemes in the related art that are similar to those disclosed in this application may also be alternated, changed, rearranged, decomposed, combined, or deleted.

[0114] In the description of the present application, the directions or positional relationships indicated by words such as "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the exemplary directions or positional relationships shown in the accompanying drawings. They are for the convenience of describing or simplifying the description of the embodiments of the present application, and do not indicate or imply that the referred device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.

[0115] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0116] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0117] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0118] The above is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the technical concept of the scheme of the present application, other similar implementation methods based on the technical ideas of the present application are also within the protection scope of the embodiments of the present application.

Claims

1. A method for managing a hybrid propulsion system for a ship, characterized in that: The ship hybrid propulsion system comprises a generator set and a lithium battery pack for supplying power to a load, and the lithium battery pack is also used to store electrical energy. The method comprises: Acquiring system adjustment information, wherein the system adjustment information includes at least one of the remaining power of the lithium battery pack, the load power, and the number of generator sets; If it is determined that the system adjustment information meets the preset conditions, the working state of the system is adjusted according to the preset conditions met, and the working state includes at least one of charging and discharging of the lithium battery pack, increasing and decreasing of the generator set, and load unloading.

2. The ship hybrid propulsion system management method according to claim 1, characterized in that: The system further comprises a DC power distribution module provided with a rectifier, a DC bus, and a bidirectional DC converter, wherein the DC power distribution module is connected to the load, the generator set is connected to the DC bus via the rectifier, the lithium battery pack is connected to the DC bus via the bidirectional DC converter, and the droop characteristic slope of the bidirectional DC converter is smaller than the droop characteristic slope of the rectifier; The method comprises: Acquiring power change information through the DC bus; If it is determined that the power change information satisfies the power change condition, the output voltage or output current of the rectifier and / or the DC voltage set value and current limit of the bidirectional DC converter are adjusted according to the power change information to perform load transfer.

3. The ship hybrid propulsion system management method according to claim 1, characterized in that: The system adjustment information includes the remaining power of the lithium battery pack, the preset condition includes that the remaining power of the lithium battery pack is within a preset range, and adjusting the working state of the system according to the satisfied preset condition includes: If it is determined that the remaining power of the lithium battery pack is within a preset range, the generator set is controlled to operate at a preset load rate, and the charging and discharging of the lithium battery pack is controlled according to the current power demand to perform peak shaving and valley filling. The preset load rate is determined based on the fuel loss of the generator set.

4. The ship hybrid propulsion system management method according to claim 3, characterized in that: The method comprises: If it is determined that the remaining power of the lithium battery pack is not within the preset range, the lithium battery pack is controlled to be charged or discharged according to the magnitude between the remaining power and the boundary value of the preset range.

5. The ship hybrid propulsion system management method according to claim 1, characterized in that: The system adjustment information includes load power and the number of generator sets, the preset condition includes that the load power increases to a first load preset value and the number of generator sets is less than the first preset value, and adjusting the working state of the system according to the satisfied preset condition includes: After waiting for a first time, a first number of backup generators are started.

6. The ship hybrid propulsion system management method according to claim 5, characterized in that: The preset condition includes that the number of the generator sets is greater than a second preset value and the load power is reduced to a second load power, and adjusting the working state of the system according to the satisfied preset condition includes: If it is determined that the remaining power of the lithium battery pack is greater than the first predetermined threshold, then after waiting for a second time, a second number of generator sets are decoupled, and the second number is less than the second preset value; If it is determined that the remaining power of the lithium battery pack is less than the first predetermined threshold, the lithium battery pack is charged.

7. The ship hybrid propulsion system management method according to claim 1, characterized in that: The preset conditions include that all the generator sets are working and the load power increases to a predetermined value, and adjusting the working state of the system according to the satisfied preset conditions includes: If it is determined that the remaining power is less than a second predetermined threshold, unloading the preset load after waiting for a third time; If it is determined that the remaining power is greater than the second predetermined threshold, the lithium battery pack is controlled to discharge, and the preset load is unloaded according to the load power after the lithium battery pack is discharged.

8. The ship hybrid propulsion system management method according to claim 1, characterized in that: The load includes a continuous load and an intermittent load, and the calculation of the load power includes: Obtain the rated input power of each load and determine the continuous load and intermittent load according to the working conditions of the ship; determining a demand factor for the load and a simultaneous factor for the intermittent load; The load power is calculated according to the rated input power, the demand factor, and the simultaneity factor.

9. The ship hybrid propulsion system management method according to claim 8, characterized in that: The calculating the load power according to the rated input power, the required coefficient and the simultaneous coefficient comprises: Determine a first required power according to the rated input power, the required coefficient and the simultaneous coefficient; A second required power is determined based on the first required power and a grid loss, and the second required power is determined as the load power.

10. The ship hybrid propulsion system management method according to claim 9, characterized in that: The determining the first required power according to the rated input power, the required coefficient and the simultaneous coefficient comprises: By P G =∑K i ·P ci +K2·∑K j ·P Ij Calculate the first required power, where P G is the first required power, P ci is the rated input power of the i-th continuous load, P Ij is the rated input power of the i-th intermittent load, K i is the required coefficient of the i-th continuous load, K j is the required coefficient of the jth intermittent load, and K2 is the simultaneous coefficient.

Images