Ship hybrid propulsion system management method

Abstract

The application provides a ship hybrid power propulsion system management method. The ship hybrid power propulsion system comprises a generator set and a lithium battery pack for supplying power to a load and storing electric energy, and the method comprises: acquiring system regulation information, the system regulation information comprising at least one of the residual capacity of the lithium battery pack, the load power and the number of generator sets; if it is determined that the system regulation information meets a preset condition, adjusting the working state of the system according to the met preset condition, the working state comprising at least one of the charging and discharging of the lithium battery pack, the increase and decrease of the generator set and the unloading of the load. The application can automatically adjust the working state of the lithium battery pack, the increase and decrease of the generator set and the like according to the system regulation information, effectively avoid the occurrence of system failure, reduce the operation cost and maintenance cost, fully exert the advantages of the hybrid power system, improve the energy utilization efficiency and the adaptability to various working conditions of the ship.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ship power management, in particular, the present application relates to a ship hybrid power propulsion system management method. BACKGROUND

[0002] As an important means of transportation, the energy saving and emission reduction of the power system of the ship has always been the focus of the industry. The traditional ship power system mainly uses diesel engine or other fossil fuel generator as power source, which has the problems of low energy utilization efficiency, large pollutant emission, high operation cost, and large safety hidden danger. In order to solve the above problems, in recent years, hybrid power system has been widely concerned and applied in the field of ship.

[0003] The hybrid power system combines generator set and lithium battery pack. This way can make full use of the high energy density characteristics of fossil fuel used by generator set and the advantages of easy control and no pollution of electric propulsion, so as to significantly improve the energy utilization efficiency and reduce the emission of harmful gas. As an auxiliary power source, lithium battery pack can provide additional power support when the ship needs to accelerate, climb or cope with high load conditions, so as to ensure the stability and reliability of power output. In addition, the energy storage function of lithium battery pack can also recover excess energy when the ship decelerates, brakes or idles, so as to improve the overall sailing efficiency and endurance.

[0004] However, the existing ship hybrid power system often takes the lithium battery pack as a backup energy source or controls the lithium battery pack to charge and discharge in a fixed time period in terms of energy management strategy and battery charge and discharge control strategy. These strategies are not reasonable and are easy to make the generator set or lithium battery pack work in overload or idle state for a long time, which is easy to cause system failure, increase operation cost and maintenance cost, and is difficult to fully exert the advantages of hybrid power system, low energy utilization efficiency and poor adaptability to various working conditions of the ship. SUMMARY

[0005] The present application is aimed at the shortcomings of the prior art, and provides a ship hybrid power propulsion system management method, which can solve the problems of existing strategies that are easy to cause system failure, increase operation cost and maintenance cost, difficult to fully exert the advantages of hybrid power system, low energy utilization efficiency and poor adaptability to various working conditions of the ship.

[0006] According to one aspect of the embodiments of the present application, the embodiments of the present application provide a ship hybrid power propulsion system management method, the ship hybrid power propulsion system comprising a generator set and a lithium battery pack for supplying power to a load, and the lithium battery pack is also used for storing electric energy, and the method comprises:

[0007] obtaining system adjustment information, the system adjustment information comprising 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 a preset condition, the working state of the system is adjusted according to the preset condition that meets, 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 unloading of the load.

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

[0010] The method includes:

[0011] Power change information is obtained through the direct-current bus.

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

[0013] In one possible implementation, the system adjustment information includes the residual capacity of the lithium battery pack, the preset condition includes that the residual capacity of the lithium battery pack is in a preset range, and the working state of the system is adjusted according to the preset condition that meets, including:

[0014] If it is determined that the residual capacity of the lithium battery pack is in the preset range, the generator set is controlled to work at a preset load rate, and the lithium battery pack is controlled to charge and discharge according to the current power demand to perform peak clipping and valley filling, and the preset load rate is determined according to the fuel consumption of the generator set.

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

[0016] If it is determined that the residual capacity of the lithium battery pack is not in the preset range, the lithium battery pack is controlled to charge or discharge according to the size of the residual capacity and the boundary value of the preset range.

[0017] In one possible implementation, the complexity includes simple, medium and complex, different complexity corresponds to different proportional coefficients of the super-division model, and the proportional coefficients are used to adjust the use proportion of the convolution branch and the self-attention branch.

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

[0019] After waiting for a first time, starting a first number of standby generator sets.

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

[0021] If it is determined that the remaining power of the lithium battery pack is greater than a first predetermined threshold value, waiting for a second time, and then disconnecting a second number of generator sets, the second number being 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 value, charging the lithium battery pack.

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

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

[0025] If it is determined that the remaining power is greater than the second predetermined threshold value, controlling the lithium battery pack to discharge, and unloading the preset load according to a load power after the lithium battery pack discharges.

[0026] In a possible implementation, the load comprises a continuous load and an intermittent load, and the calculating the load power comprises:

[0027] Obtaining rated input powers of the loads, and determining the continuous load and the intermittent load according to a working condition of the ship;

[0028] Determining a required coefficient of the load and a simultaneous coefficient of the intermittent load;

[0029] Calculating the load power according to the rated input power, the required coefficient, and the simultaneous coefficient.

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

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

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

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

[0034] determining the first required power by P G =∑K i ·P ci +K2·∑K j ·P Ij , wherein P G is the first required power, P ci is the rated input power of the ith continuous load, P Ij is the rated input power of the jth intermittent load, K i is the required coefficient of the ith continuous load, K j is the required coefficient of the jth intermittent load, and K2 is the simultaneous coefficient.

[0035] The technical scheme provided by the embodiments of the present application has the beneficial technical effects including:

[0036] The ship hybrid power propulsion system management method provided by the present application has the beneficial effects that system adjustment information is acquired; if it is determined that the system adjustment information meets a preset condition, the working state of the system is adjusted according to the preset condition that is met, the working state including at least one of charging and discharging of the lithium battery pack, increasing and decreasing of the generator set, and unloading of the load, the present application can automatically adjust the working state such as charging and discharging of the lithium battery pack and increasing and decreasing of the generator set according to the system adjustment information, effectively avoiding the occurrence of system failure, reducing operation cost and maintenance cost, fully exerting the advantages of the hybrid power system, improving energy utilization efficiency, and improving the adaptability to various working conditions of the ship.

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

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

[0039] Figure 1 a flowchart of the ship hybrid power propulsion system management method provided by the embodiments of the present application;

[0040] Figure 2 A structural diagram of a ship hybrid propulsion system provided by an embodiment of the present application is shown in FIG. 1.

[0041] Figure 3 A schematic diagram of a generator set and lithium battery pack management provided by an embodiment of the present application is shown in FIG. 2.

[0042] 1, generator set; 2, lithium battery pack; 3, DC power distribution module; 31, rectifier; 32, bidirectional DC converter; 33, DC bus; 34, inverter unit; 35, inverter; 41, voltage conversion module; 42, propulsion motor; 5, AC power distribution module; 51, first bus; 52, second bus; 53, third bus; 61, first transformer; 62, second transformer. DETAILED DESCRIPTION

[0043] Embodiments of the present application will be described below in conjunction with the accompanying drawings. It should be understood that the embodiments described below in conjunction with the accompanying drawings are exemplary descriptions of the technical solutions of the embodiments of the present application, and do not limit the technical solutions of the embodiments of the present application.

[0044] Those skilled in the art can understand that, unless specifically stated, "said" and "the" used herein can also include plural forms. It should be further understood that the phrase "comprising" used in the specification of the present application means that the features, integers, steps, operations, elements and / or components exist, but does not exclude other features, information, data, steps, operations, elements, components and / or combinations thereof supported by the present technology. It should be understood that when we say that an element is "connected" or "coupled" to another element, the element can be directly connected or coupled to the other element, or can mean that the element and the other element are connected through an intermediate element. In addition, "connected" or "coupled" used herein can include wireless connection or wireless coupling. The term "and / or" used herein means at least one of the items defined by the term, for example, "A and / or B" can be implemented as "A", or as "B", or as "A and B".

[0045] To make the purpose, technical solutions and advantages of the present application clearer, the embodiments of the present application will be described in further detail below in conjunction with the accompanying drawings.

[0046] The embodiments of the present application provide a ship hybrid propulsion system management method, which can be used in a ship hybrid propulsion system. The ship hybrid propulsion system includes a generator set 1 and a lithium battery pack 2 for supplying power to a load, and the lithium battery pack 2 is also used for storing electric energy. The ship hybrid propulsion system manages the generator set 1, the lithium battery pack 2 and the load in real time through the method.

[0047] In one embodiment, the lithium battery pack 2 can employ lithium iron phosphate batteries, with a single cell rated capacity of 100 ampere-hours, a total of 200 strings, 104 cells per string, and a total capacity of 2080 kilowatt-hours. The lithium battery pack 2 has a maximum charging power of 200 kilowatts and a maximum discharging power of 300 kilowatts. The battery pack allows a working temperature range of -20°C to 55°C.

[0048] In one embodiment, the lithium battery pack 2 can employ ternary lithium batteries, with a single cell rated capacity of 120 ampere-hours, a total of 180 strings, 120 cells per string, and a total capacity of 2592 kilowatt-hours. The lithium battery pack 2 has a maximum charging power of 300 kilowatts and a maximum discharging power of 400 kilowatts. The lithium battery pack 2 allows a working temperature range of 0°C to 45°C.

[0049] In one embodiment, the lithium battery pack 2 can employ lithium manganese batteries, with a single cell rated capacity of 150 ampere-hours, a total of 160 strings, 128 cells per string, and a total capacity of 3072 kilowatt-hours. The lithium battery pack 2 has a maximum charging power of 400 kilowatts and a maximum discharging power of 500 kilowatts. The lithium battery pack 2 allows a working temperature range of -10°C to 50°C.

[0050] Optionally, the ship hybrid propulsion system can further include a power management system, and the propulsion system can perform the method of the present application through the power management system. The power management system can be provided with a computer, a CPU, and other devices capable of adjusting the working state of the propulsion system according to system adjustment information, or can be provided with a communication device connected to the cloud, through which the charging and discharging information is sent to the cloud, and the working state is adjusted according to the feedback information transmitted by the cloud.

[0051] In one embodiment, as shown in Figure 3 , the power management system can include a control master station and a PMS (Power Management System) human-machine interface, and the control master station is connected with the PMS human-machine interface. The control master station can control the working state of the propulsion system according to the system adjustment information after obtaining 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 instruction input by the user.

[0052] As shown in Figures 1-3 , the ship hybrid propulsion system management method of the present application includes:

[0053] S101: Obtain system adjustment information.

[0054] Optionally, the system adjustment information includes at least one of the remaining power of the lithium battery pack 2, the load power, and the number of generator sets 1.

[0055] Optionally, the ship hybrid propulsion system can be provided with multiple sensors for collecting system regulation information, which can be arranged in the lithium battery pack 2, the generator set 1 and the current transmission line of the system. The arrangement position of the sensor can be set according to the type of information collected, the position of the object collected and other information.

[0056] Optionally, it can be detected whether the propulsion system is currently started to work, and if it is determined that the system is started to work, the collection of the system regulation information is performed. It can also be detected whether the information collection condition is currently met, and if it is determined that the information collection condition is met, the collection of the system regulation information is performed. The information collection condition can include at least one of receiving an information collection instruction, the current ship being in a preset working mode, the lithium battery pack 2 working normally and the like.

[0057] Optionally, the propulsion system can further include a direct current power distribution module 3 provided with a rectifier 31 (AC / DC), a direct current bus 33 and a bidirectional direct current converter 32 (DC / DC), the direct current power distribution module 3 is connected with the load, the generator set 1 is connected with the direct current bus 33 through the rectifier 31, the lithium battery pack 2 is connected with the direct current bus 33 through the bidirectional direct current converter 32, and the droop characteristic slope of the bidirectional direct current converter 32 is smaller than the droop characteristic slope of the rectifier 31.

[0058] Optionally, the droop characteristic slope of the bidirectional direct current converter 32 can be controlled based on the voltage mode of the direct current bus 33. The bidirectional direct current 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 change of the output voltage of the bidirectional direct current converter 32 when the output power changes is more gentle, thereby being beneficial to the stable operation of the propulsion system and the accurate management of the power.

[0059] In one embodiment, as shown in Figure 3 the generator set 1 can be a diesel generator, the number of the diesel generators can be 3, the number of the lithium battery packs 2 can be 3, each diesel generator is connected with the control master station through a rectifier 31, the control master station is connected with the lithium battery pack 2 through a bidirectional direct current converter 32, and the bidirectional direct current converters 32 connected with different lithium battery packs 2 are different.

[0060] Optionally, the method of the application further includes: acquiring power change information through the direct current bus 33; if it is determined that the power change information meets a power change condition, adjusting the output voltage or output current of the rectifier 31 and / or the direct current voltage given value and current limit value (such as setting the range of the output current) of the bidirectional direct current converter 32 to perform load transfer according to the power change information. The power change condition can be power surge (such as the power increased in a set time period being greater than a first threshold value) or power drop (such as the power decreased in a set time period being greater than a second threshold value).

[0061] Optionally, the power change information can be the voltage and / or current change information of the DC bus 33. The voltage and current of the DC bus 33 can be collected, the power of the propulsion system can be calculated based on the voltage and current, and then the power change information can be obtained based on the power.

[0062] Optionally, the power change information can be collected by the power management system. The power management system can control the power output of the bidirectional DC converter 32 by adjusting the DC voltage set value of the bidirectional DC converter 32. This adjustment method can flexibly adjust the working state of the bidirectional DC converter 32 according to the actual demand of the propulsion system, so as to realize the optimal distribution and efficient utilization of energy.

[0063] Optionally, when a power surge or a power drop is detected through the DC bus 33, the bidirectional DC converter 32 can first bear most of the power surge or power drop (the droop characteristic slope of the bidirectional DC converter 32 is small, and the change of the output voltage is gentle), and then the power management system can gradually transfer the increased or decreased load to the rectifier 31. The gradual transfer of the load can be realized by adjusting the output voltage or current of the rectifier 31 and controlling the connection or disconnection of the load.

[0064] Optionally, the control parameters (such as the voltage parameters, current parameters, and efficiency parameters of the rectifier 31, the output voltage, output current, ripple, and transient response of the bidirectional DC converter) or the working mode of the rectifier 31 or the bidirectional DC converter 32 can be adjusted to transfer the load and reduce the impact on the propulsion system when the power change information meets the power change condition.

[0065] In one embodiment, there are two generator sets 1 and two lithium battery groups 2. The power management system controls the rectifier 31 and the bidirectional DC converter 32 in the DC bus 33 voltage mode. 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 can be set to 1.2. The power management system controls the power of the bidirectional DC converter 32 by adjusting the DC voltage set value of the bidirectional DC converter 32. When a power surge or a power drop occurs in the DC bus 33, the bidirectional DC converter 32 can bear most of the power surge or power drop, and then the power management system can gradually transfer the increased or decreased load to the rectifier 31. The maximum charging power of the bidirectional DC converter 32 is set to 200 kW, and the maximum discharging power is set to 300 kW.

[0066] In one embodiment, the propulsion system includes two generator sets 1, two lithium battery sets 2, the power management system adopts 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 given value of the bidirectional DC converter 32. 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 gradually transfers the increased or decreased load to the rectifier 31 controlled by the power management system. The maximum charging power of the bidirectional DC converter 32 is set to 300 kW, and the maximum discharging power is set to 400 kW.

[0067] In one embodiment, the propulsion system includes three generator sets 1, one lithium battery set 2, the power management system adopts 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 given value of the bidirectional DC converter 32. 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 gradually transfers the increased or decreased load to the rectifier 31 controlled by the power management system. The maximum charging power of the bidirectional DC converter 32 is set to 400 kW, and the maximum discharging power is set to 500 kW.

[0068] Optionally, as shown in Figure 2 The DC power distribution module 3 can also include an inverter unit 34 and an inverter 35, and the propulsion system can also include an AC power distribution module 5, a voltage conversion module 41, and a first transformer 61 and a second transformer 62, the inverter unit 34 is connected with 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 side propulsion motor and the propulsion motor at other positions of the ship. The voltage conversion module 41 is connected with 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 voltage conversion module 41, and also can receive the AC power transmitted by the voltage conversion module 41 and transmit the AC power to the DC bus 33, so as to charge the lithium battery set 2 through the DC bus 33.

[0069] Optionally, the AC matching module can include an AC bus and a control switch, the control switch controls the connection of the AC bus with the transformer and the shore power box (a device for supplying power to the ship), the power 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 with the load and the first transformer 61 and the second transformer 62. Among them, the AC bus can 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 with the third bus 53 through the first transformer 61, and the second bus 52 is connected with the third bus 53 through the second transformer 62.

[0070] S102: If it is determined that the system adjustment information meets the preset condition, adjusting the working state of the system according to the met preset condition.

[0071] 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 unloading of the load.

[0072] Optionally, the system adjustment information includes the remaining capacity of the lithium battery pack 2, the preset condition includes that the remaining capacity of the lithium battery pack 2 is in a preset range, and adjusting the working state of the system according to the met preset condition includes: if it is determined that the remaining capacity of the lithium battery pack 2 is in the preset range, controlling the generator set 1 to work at a preset load rate, and controlling the lithium battery pack 2 to charge and discharge according to the current power demand to perform peak clipping and valley filling, the preset load rate being determined according to the fuel consumption of the generator set 1.

[0073] Optionally, the preset load rate can be the load rate when the fuel consumption of the generator set 1 is the optimal consumption (at this time, the electric energy generated per unit of fuel consumed is the highest).

[0074] Optionally, the preset range can be 50%-95%, when the remaining capacity of the lithium battery pack 2 is in the range, the lithium battery pack 2 is controlled to normally charge and discharge, and the generator set 1 is controlled to work at a preset load rate, the remaining or insufficient power is provided by the lithium battery pack 2, and the lithium battery pack 2 realizes peak clipping and valley filling through charging and discharging.

[0075] Optionally, if it is determined that the remaining capacity of the lithium battery pack 2 is not in the preset range, the lithium battery pack 2 is controlled to charge or discharge according to the size of the boundary value of the remaining capacity and the preset range.

[0076] Optionally, if the remaining capacity 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.

[0077] In one embodiment, the propulsion system includes three generator sets 1 and two lithium battery banks 2, the preset range can be 50%-95%, if the remaining power of the lithium battery bank 2 is less than 50%, the lithium battery bank 2 is controlled to only charge and not discharge, if the remaining power is greater than 95%, the lithium battery bank 2 is controlled to only discharge and not charge.

[0078] In one embodiment, the propulsion system includes two generator sets 1 and two lithium battery banks 2, the preset range can be 60%-90%, the preset load rate can be that the generator set 1 works at 75% rated power, if the remaining power of the lithium battery bank 2 is less than 60%, the lithium battery bank 2 is controlled to only charge and not discharge, if the remaining power is greater than 90%, the lithium battery bank 2 is controlled to only discharge and not charge.

[0079] In one embodiment, the propulsion system includes three generator sets 1 and one lithium battery bank 2, the preset range can be 55%-85%, the preset load rate can be that the generator set 1 works at 70% rated power, if the remaining power of the lithium battery bank 2 is less than 55%, the lithium battery bank 2 is controlled to only charge and not discharge, if the remaining power is greater than 85%, the lithium battery bank 2 is controlled to only discharge and not charge.

[0080] Optionally, the system adjustment information includes 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 a first preset value, and the working state of the propulsion system is adjusted according to the satisfied preset condition, including: after waiting for a first time, starting a first number of standby generators. The load power can be the power required to provide for the current load work. The first preset value can be the total number of generator sets 1.

[0081] In one embodiment, the number of generator sets 1 is three, the first load preset value can be 85% of the rated power of the ship system, the first preset value can be 5, the first time can be 15 seconds, and the first preset number can be 1. When the number of power supply generator sets 1 is less than three and the load power increases to 85% of the rated power, a generator set 1 is automatically started after a delay of 15 seconds.

[0082] Optionally, the preset condition includes that the number of generator sets 1 is greater than a second preset value and the load power decreases to a second load power, and the working state of the system is adjusted according to the satisfied preset condition, including: if it is determined that the remaining power of the lithium battery bank 2 is greater than a first predetermined threshold, waiting for a second time, and then splitting a second number of generator sets 1, the second number is less than the second preset value; if it is determined that the remaining power of the lithium battery bank 2 is less than the first predetermined threshold, charging the lithium battery bank 2. The second preset value is less than the first preset value.

[0083] In one embodiment, the number of generator sets 1 is 3, the second preset value can be 1, the second load power can be 30%, the first predetermined threshold can be 95%, and the second time can 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 > 95%, one generator set 1 is automatically tripped after a delay of 30s, and if the remaining power < 95%, the lithium battery pack 2 is preferentially charged.

[0084] 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 is increased to 90% of the rated power, another generator set 1 is automatically started after a delay of 10s. When the number of generator sets 1 on the grid is 2 and the load power is reduced to 25% of the rated power, if the remaining power of the lithium battery pack 2 > 90%, one generator set 1 is automatically tripped after a delay of 20s, and if the remaining power of the lithium battery pack 2 < 90%, the lithium battery pack 2 is preferentially charged.

[0085] 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 is increased to 80% of the rated power, another generator set 1 is automatically started after a delay of 20s. When the number of generator sets 1 on the grid is 3 and the load power is reduced to 35% of the rated power, if the remaining power of the lithium battery pack 2 > 85%, one generator set 1 is automatically tripped after a delay of 40s, and if the remaining power of the lithium battery pack 2 < 85%, the lithium battery pack 2 is preferentially charged.

[0086] Optionally, the preset conditions include that all generator sets 1 are working and the load power is increased to a predetermined value, and the working state of the system is adjusted according to the satisfied preset conditions, including: if it is determined that the remaining power is less than a second predetermined threshold, the preset load is unloaded after a third time; if it is determined that the remaining power is greater than the second predetermined value, the lithium battery pack 2 is discharged, and the preset load is unloaded according to the load power after the lithium battery pack 2 is discharged. Wherein, after the lithium battery pack 2 is discharged, if it is detected that the load power is not effectively reduced (such as not reduced within a fourth time), the preset load is unloaded.

[0087] Optionally, the preset load can be air conditioning, oven and other non-critical loads that do not affect the navigation of the ship, and a trip coil can be provided on the power switch of these loads, and the power switch is disconnected through the trip coil, so as to realize the rapid unloading of the preset load.

[0088] In one embodiment, the predetermined value can be 90% rated power, the number of generator sets 1 is 3, the second predetermined threshold can be 50% rated power, and the third time can be 10 seconds. When the number of on-grid units is equal to 3 (and all generator sets 1 supply power) and the load increases to 90% 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 preferentially discharge (the priority of charging is lower than that of discharging), and when the lithium battery pack 2 reaches its set discharge power and the load power is still >90% rated power, the non-critical load is automatically unloaded after a delay of 10 seconds.

[0089] In one embodiment, the predetermined value can be 95% rated power, the number of generator sets 1 is 2, the second predetermined threshold can be 60% rated power, and the third time can be 5 seconds. When the number of on-grid units is equal to 2 (and all generator sets 1 supply power) and the load increases to 95% 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 preferentially discharge (the priority of charging is lower than that of discharging), and when the lithium battery pack 2 reaches its set discharge power and the load power is still >95% rated power, the non-critical load is automatically unloaded after a delay of 5 seconds.

[0090] In one embodiment, the predetermined value can be 92% rated power, the number of generator sets 1 is 3, the second predetermined threshold can be 55% rated power, and the third time can be 15 seconds. When the number of on-grid units is equal to 3 (and all generator sets 1 supply power) and the load increases to 92% rated power, if the remaining power of the lithium battery pack 2 is <55%, the non-critical load such as air conditioning distribution box, kitchen distribution box, and driver room air conditioner is automatically unloaded after a delay of 15 seconds, if the remaining power is >55%, the lithium battery pack 2 is controlled to preferentially discharge (the priority of charging is lower than that of discharging), and when the lithium battery pack 2 reaches its set discharge power and the load power is still >92% rated power, the non-critical load is automatically unloaded after a delay of 15 seconds.

[0091] Optionally, to effectively protect and manage the lithium battery pack 2, the propulsion system can further include a battery temperature detection module, a battery voltage detection module, and a battery current detection module, through which the voltage, temperature, and current of the lithium battery pack 2 are collected, and the charging and discharging mode of the battery is dynamically adjusted according to the above strategy, thereby improving the use efficiency of the lithium battery pack 2.

[0092] Optionally, the calculation of the load power can be realized by using a required coefficient method, a three-class load method, a day and night load method, a probability analysis calculation method, a formula calculation method, and a calculation method based on a certain heavy load, and the selection and use of the calculation method can be determined according to the purpose of the ship.

[0093] Optionally, the loads include continuous loads and intermittent loads, and the calculation of the load power comprises: obtaining rated input power of each load, determining the continuous loads and the intermittent loads according to the working conditions of the ship; determining a required coefficient of the load and a simultaneous coefficient of the intermittent load; and calculating the load power according to the rated input power, the required coefficient and the simultaneous coefficient.

[0094] Optionally, the working conditions of the ship can include information in the conditions of sailing, entering and leaving a port, approaching and leaving a wharf, anchoring, loading and unloading, etc. The information corresponding to the sailing includes a full-load full-speed sailing state, the information corresponding to the entering and leaving a port includes a low-speed sailing or maneuvering state in a port, the information corresponding to the approaching and leaving a wharf includes an anchor lifting and mooring state, sometimes the working condition is combined with the entering and leaving a port as the entering and leaving a port, the information corresponding to the anchoring includes an anchoring wharf or mooring a ship without passengers or goods, and the information corresponding to the loading and unloading includes a cargo ship, a liquid cargo ship (an oil tanker, a liquefied gas tanker and a chemical tanker) or a container ship in a loading or unloading state.

[0095] Optionally, the load is an electric device, which includes (1) auxiliary machinery for power devices, such as oil pumps, sea water cooling pumps, fresh water cooling pumps, air blowers and the like, which serve the main engine and the main boiler; (2) deck machinery, including anchor machines, winches, steering machines, cargo winches, gangways, boat launching machines and the like; (3) cabin auxiliary machinery, including water pumps for living, fire pumps, bottom pumps and auxiliary machinery for auxiliary boilers and the like; (4) machine repair machinery, including lathes, drilling machines, electric welding machines and turning gears and the like; (5) refrigeration and ventilation, including auxiliary machinery for air conditioning devices, food refrigerators and ventilation machines and the like; (6) kitchen equipment, including auxiliary machinery for kitchen machinery such as electric stoves, electric ovens and the like, and electric tea stoves and the like; (7) lighting equipment, including lighting equipment such as engine room lighting, cabin lighting, deck lighting and the like, navigation lights, signal lights and electric fans and the like; weak current equipment, including radio communication, navigation, crew and ship safety and shipboard communication equipment and the like; (9) automation equipment and the like, such as automation devices, battery charging equipment, refrigerated containers, bow thruster devices and special equipment for special ships and the like. The classification of the electric device is greatly different with the type, tonnage and main engine type of the ship, and the electric device can be increased, decreased or combined when the load power is calculated.

[0096] Optionally, the required coefficient = maximum required power of the device / rated input power of the device * 100%. The rated input power of the device is the rated input power of the electric motor, the total power of the lighting and weak current equipment is taken as the rated power for the lighting and weak current equipment, and the average power is taken as the rated input power for the device with power fluctuation over time.

[0097] Optionally, the required coefficient is different with the working condition of the ship, and for a general merchant ship, the following values can be taken:

[0098] General auxiliary equipment: 60%-95%;

[0099] Servo motors: 20%–30%;

[0100] Electric heating equipment: 50%–100%;

[0101] General lighting: 70%–80% (navigation), 60%–70% (loading and unloading), 50%–60% (berthing);

[0102] Work lights: 100% (loading and unloading).

[0103] Optionally, when the air conditioner is a split-type air conditioner, it is an intermittent load; when the air conditioner is a central air conditioner, it can be a continuous load. Furthermore, the demand factor when the air conditioner is an intermittent load is greater than the demand factor when the air conditioner is a continuous load.

[0104] Alternatively, the intermittent loads may not be used at the same time, so under certain conditions, the sum of the maximum power requirements of the intermittent loads that may be operating is smaller than the sum of the maximum power requirements of all intermittent loads.

[0105] Wherein, the simultaneous coefficient = the sum of the maximum required power of all intermittent loads / the sum of the maximum required power of each possible intermittent load.

[0106] The simultaneity coefficient varies depending on the ship's operating state. It is also influenced by factors such as the ship's loading status, navigation area, and season, and is typically determined based on experience and actual test results. When a precise calculated value is unavailable, the simultaneity coefficient can be set between 0.3 and 0.5.

[0107] Optionally, the load power is calculated based on the rated input power, the demand factor, and the simultaneity factor, including: determining a first required power based on the rated input power, the demand factor, and the simultaneity factor; determining a second required power based on the first required power and grid losses; and determining the second required power as the load power.

[0108] Optionally, the first required power is determined based on the rated input power, the demand factor, and the simultaneity factor, including: via P G =∑K i ·P ci +K2·∑K j ·P Ij Calculate the first required power, where P G For the first required power, P ci P is the rated input power of the i-th continuous load. Ij K is the rated input power of the i-th intermittent load. i K is the demand factor for the i-th consecutive load. j K1 is the demand factor for the j-th intermittent load, and K2 is the simultaneity factor.

[0109] In one embodiment, the calculation of the load power can include: calculating the rated input power of each electrical device. Determining the electrical devices required to be used under each working condition, thereby identifying continuous loads and intermittent loads. Determining the demand factor of each electrical device. Calculating the required power of each electrical device, and calculating the total required power of the electrical devices under each working condition. Determining the simultaneous factor of the intermittent loads, and calculating the first required power. When calculating the first required power, if there is a larger load in the intermittent loads, the sum of the required power of the continuous loads (∑K i ·P ci ) plus the required power of the largest intermittent load (∑K j ·P Ij ) plus the sum of the required power of the other intermittent loads (K2·∑K (j-1) ·P I(j-1) ) 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.

[0110] Optionally, after the load power under the normal state of the ship is calculated, the capacity and the number of the generator set 1 can also be determined according to the load power, and the load rate of the generator set 1 under each working condition (the ratio of the load power under each working condition to the total rated power of the generator set 1) is calculated, and the charging and discharging of the lithium battery pack 2 under different working conditions is controlled according to the load rate.

[0111] The ship hybrid propulsion system management method of the present application obtains system regulation information; if it is determined that the system regulation information meets a preset condition, the working state of the system is adjusted according to the preset condition that is 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 unloading of the load. The present application can automatically adjust the working state such as the charging and discharging of the lithium battery pack and the increase and decrease of the generator set according to the system regulation information, effectively avoid the occurrence of system failure, reduce the operation cost and maintenance cost, fully exert the advantages of the hybrid power system, improve the energy utilization efficiency, and improve the adaptability to various working conditions of the ship.

[0112] Those skilled in the art can understand that the steps, measures, and schemes in the various operations, methods, and processes discussed in the present application can be alternated, changed, combined, or deleted. Further, other steps, measures, and schemes in the various operations, methods, and processes discussed in the present application can also be alternated, changed, rearranged, decomposed, combined, or deleted. Further, the steps, measures, and schemes in the various operations, methods, and processes in the related art can also be alternated, changed, rearranged, decomposed, combined, or deleted.

[0113] In the description of the present application, the directions or positional relationships indicated by the words "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the exemplary directions or positional relationships shown in the drawings, and 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 devices or components indicated thereby must have a particular orientation, or be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0114] The terms "first", "second", "third", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implying that the indicated technical features are limited to a certain number. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0115] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral connection; can be directly connected, or indirectly connected through an intermediate medium; can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0116] In the description of the present application, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0117] The above only describes some embodiments of the present application, and it should be pointed out that, for those skilled in the art, without departing from the technical concept of the present application, other similar implementation means based on the technical idea of the present application also belong to the protection scope of the embodiments of the present application.

Claims

1. A management method for a marine hybrid propulsion system, characterized in that, The ship hybrid propulsion system includes a DC power distribution module equipped with a rectifier, a DC bus, a bidirectional DC converter, a generator set for supplying power to a load, and a lithium battery pack, wherein the lithium battery pack is also used for storing electrical energy. 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. The droop slope of the bidirectional DC converter is less than the droop slope of the rectifier. The method includes: Acquire system adjustment information, which includes at least one of the following: 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. The working state includes at least one of charging and discharging of the lithium battery pack, adding or removing generator sets, and unloading the load. The preset conditions include that the remaining power of the lithium battery pack is within a preset range. Adjusting the system's operating state according to satisfied preset conditions 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 lithium battery pack is controlled to charge and discharge according to the current power demand to perform peak shaving and valley filling. The preset load rate is determined based on the fuel consumption of the generator set. The method includes: Power change information is obtained through the DC bus; If the power change information is determined to meet the power change conditions, the output voltage or output current of the rectifier and / or the DC voltage setpoint and current limit of the bidirectional DC converter are adjusted according to the power change information to perform load transfer.

2. The method for managing a ship hybrid propulsion system according to claim 1, characterized in that, The method includes: If it is determined that the remaining power of the lithium battery pack is not within a preset range, the charging or discharging of the lithium battery pack is controlled according to the boundary value between the remaining power and the preset range.

3. The method for managing a ship hybrid propulsion system according to claim 1, characterized in that, The system adjustment information includes load power and the number of generator sets. The preset conditions include the load power increasing to a first preset load value and the number of generator sets being less than a first preset value. Adjusting the system's operating state according to the satisfied preset conditions includes: After waiting for the first opportunity, start the first number of backup generators.

4. The method for managing a ship hybrid propulsion system according to claim 3, characterized in that, The preset conditions include the number of generator sets being greater than a second preset value and the load power being reduced to a second load power. Adjusting the system's operating state according to the satisfied preset conditions 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 disconnected, the second number being 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, then the lithium battery pack is charged.

5. The method for managing a ship hybrid propulsion system according to claim 1, characterized in that, The preset conditions include all generator sets operating and the load power increasing to a predetermined value. Adjusting the system's operating state according to the satisfied preset conditions includes: If it is determined that the remaining power is less than the second predetermined threshold, the preset load will be unloaded after a third period of 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.

6. The method for managing a ship hybrid propulsion system according to claim 1, characterized in that, The load includes continuous load and intermittent load, and the calculation of the load power includes: Obtain the rated input power of each load and determine continuous load and intermittent load based on the ship's operating conditions; Determine the demand factor of the load and the simultaneity factor of the intermittent load; The load power is calculated based on the rated input power, the demand factor, and the simultaneity factor.

7. The method for managing a ship hybrid propulsion system according to claim 6, characterized in that, The calculation of the load power based on the rated input power, the demand factor, and the simultaneity factor includes: The first required power is determined based on the rated input power, the demand factor, and the simultaneity factor. The second required power is determined based on the first required power and the grid loss, and the second required power is determined as the load power.

8. The method for managing a ship hybrid propulsion system according to claim 7, characterized in that, Determining the first required power based on the rated input power, the demand factor, and the simultaneity factor includes: pass Calculate the first required power, where, The first power required, The rated input power of the i-th continuous load, Let i be the rated input power of the i-th intermittent load. Let be the demand factor for the i-th consecutive load. Let be the demand factor for the j-th intermittent load. This is the simultaneity coefficient.

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