A multi-unit diesel storage energy management method, system and multi-unit diesel storage system

Abstract

The present application relates to the technical field of new energy energy management, and particularly relates to a multi-generator diesel storage energy management method, system and multi-generator diesel storage system. The multi-generator diesel storage energy management method comprises the following steps: acquiring the current SOC of the energy storage battery in real time, determining the charging and discharging state of the energy storage battery according to the SOC; determining the number of diesel generator sets to start based on the charging and discharging state of the energy storage battery; determining the total output power PG of the diesel generator set based on the charging and discharging state of the energy storage battery and the number of diesel generator sets to start. Not only can the output power of the diesel generator set be continuously adjusted according to the charging and discharging state and the SOC state to ensure that the diesel generator set works in the high-efficiency zone as much as possible and reduces energy loss, but also the energy management under the multi-generator working condition can be applied, which is easy to implement and has a wide application prospect in the energy management of diesel storage hybrid power ships.

Description

Technical Field

[0001] This invention relates to the field of new energy energy management technology, and in particular to a multi-unit diesel-storage energy management method, system, and multi-unit diesel-storage system. Background Technology

[0002] Energy conservation and emission reduction are of significant research value to the shipping industry, as they can reduce ship operating costs and bring social and environmental benefits. With the development of new energy technologies and industrial control technologies for ships, hybrid-powered ships have been widely adopted. Hybrid-powered ships primarily use energy storage batteries and diesel generators to achieve hybrid power supply, which can effectively improve the fuel efficiency of diesel generators and reduce operating costs. During operation, the energy storage battery, through energy regulation, ensures that the diesel generator operates within its high-efficiency range as much as possible. However, the energy regulation capability of the energy storage battery is limited by its power and charge / discharge state; therefore, an energy management method is needed to rationally allocate the power between the diesel generator and the energy storage battery.

[0003] Currently, research on energy management strategies for hybrid power ships in China is scarce and still in its early stages. Rule-based energy management methods are widely used in engineering, but they also have many problems, including at least the following: (1) Existing literature rarely analyzes the energy distribution between generators and batteries in multi-unit scenarios; (2) Power distribution rules are often too simplistic; after determining the battery's charging and discharging status, the battery power is only related to the load and generator power, and not to the battery's own power. (3) Changes in State of Charge; (4) Failure to consider losses in energy storage batteries and converters. Summary of the Invention

[0004] To address at least one deficiency in the existing energy management methods, in a first aspect, the present invention provides a multi-unit diesel-storage energy management method, applicable to a system with multiple diesel generator sets and energy storage batteries, comprising the following steps: Real-time acquisition of the current status of the energy storage battery According to the above Determine the charge / discharge state of the energy storage battery; The number of diesel generator sets to be started is determined based on the charge / discharge state of the energy storage battery; when the energy storage battery is in a charging state, the number of starts is determined based on the rated power of the diesel generator set. and load power Determine the number of diesel generator sets to start; when the energy storage battery is in a discharging state, determine the maximum discharge power of the energy storage battery. The optimal power value of the diesel generator set Determine the number of diesel generator sets to be started; Based on the charge / discharge state of the energy storage battery and the number of diesel generator sets started, the total output power of the diesel generator sets is determined. .

[0005] In one embodiment, according to the Determining the charge / discharge state of the energy storage battery includes: The state of charge (SOC) of the energy storage battery is divided into multiple charge ranges, and the threshold values ​​for each charge range are determined to include at least the following: and ,and ; If the above In If the battery's charge range is within a certain range, then the energy storage battery is determined to be in a charging state, and the operating mode of the energy storage battery is switched to charging mode; if the In If the energy storage battery falls within a certain range, it is determined that the energy storage battery is in a discharging state, and the operating mode of the energy storage battery is switched to the discharging mode; if ... In If the energy range is within a certain range, it is determined that the energy storage battery maintains its current charging or discharging state, and the operating mode of the energy storage battery remains the current charging or discharging mode.

[0006] In one embodiment, the threshold of the power range further includes and ,and ; When the In When the power range is within the specified range, determine the... and stated Size; if If the energy storage battery is in a discharging state, its operating mode is switched to discharge mode; if If so, it is determined that the energy storage battery maintains its current charging state or discharging state, and the operating mode of the energy storage battery maintains its current charging mode or discharging mode. When the In and When the energy range is within the specified range, it is determined whether the energy storage battery maintains its current charging or discharging state, and the operating mode of the energy storage battery remains the current charging or discharging mode.

[0007] In one embodiment, the diesel generator set consists of three units; when the energy storage battery is in a charging state, if If so, it is determined that a single diesel generator set is started and working; if If so, it is determined that the two diesel generator sets have started working; if If so, then it is determined that the three diesel generator sets mentioned above have started working; if the... Between and If the current number of diesel generator sets is maintained, then the number of such generator sets will remain unchanged. in, ;and , , , The calculation formula is: ; ; ; ; In the formula, 1.5 , , This is the hysteresis.

[0008] In one embodiment, the diesel generator set consists of three units; when the energy storage battery is in a discharging state, if If so, then it is determined that 0 of the aforementioned diesel generator sets have started working; if If so, it is determined that a single diesel generator set is started and working; if If so, it is determined that the two diesel generator sets have started working; if If so, then it is determined that the three diesel generator sets mentioned above have started working; if the... Between , and In between, the current number of diesel generator sets started remains unchanged; in, ;and , , , , , The calculation formula is: ; ; ; ; ; ; ; In the formula, , This is the hysteresis.

[0009] In one embodiment, the total output power of the diesel generator set is determined based on the charge / discharge state of the energy storage battery and the number of times the diesel generator set is started. This includes the following steps: When the energy storage battery is in a charging state, based on the SOC, the number of diesel generator sets started, and the... and the maximum power of the diesel generator set in its high-efficiency operating range. The minimum power of the diesel generator set in its high-efficiency operating range Determine the ; When the energy storage battery is in a discharged state, according to the The above The current SOC value and the optimal power value of the diesel generator set. Determine the .

[0010] In one embodiment, when the energy storage battery is in a charging state, the The calculation formula is: ; In the formula, The number of times the diesel generator set is started.

[0011] In one embodiment, when the energy storage battery is in a discharged state, the The following steps are included in the determination process: like If the diesel generator set does not work, The energy storage battery operates independently, and the total output power of the energy storage battery is... ; like Then the diesel generator set operates independently. When the energy storage battery is not working, the total output power of the energy storage battery is... ; like Then the diesel generator and the energy storage battery work simultaneously. Total output power of energy storage batteries - .

[0012] Secondly, the present invention also provides a multi-unit diesel-storage energy management system, comprising: The energy storage battery charge / discharge state determination module is used to determine the charge / discharge state of the energy storage battery in real time. Determine the charge / discharge state of the energy storage battery; The diesel generator set start quantity determination module is used to determine the start quantity of the diesel generator set based on the charging and discharging state of the energy storage battery; when the energy storage battery is in a charging state, it determines the start quantity based on the rated power of the diesel generator set. and load power Determine the number of diesel generator sets to start; when the energy storage battery is in a discharging state, determine the maximum discharge power of the energy storage battery. The optimal power value of the diesel generator set Determine the number of diesel generator sets to be started; The total output power determination module for the diesel generator set is used to determine the total output power of the diesel generator set based on the charging and discharging state of the energy storage battery and the number of diesel generator sets started. .

[0013] Thirdly, the present invention also provides a multi-unit diesel-storage system, including multiple diesel generator sets and energy storage batteries; the multiple diesel generator sets and the energy storage batteries are electrically connected to at least one load via a DC bus to supply power to the load; it also includes a multi-unit diesel-storage energy management method as described in any of the above embodiments, or a multi-unit diesel-storage energy management system as described in the above embodiments.

[0014] Based on the above, compared with the prior art, the diesel-electric storage energy management method provided by the present invention realizes the diesel-electric storage energy management strategy through three steps: determining the charge / discharge state of the energy storage battery, determining the number of diesel generator sets to be started, and determining the total output power of the diesel generator sets. This not only allows for management based on the charge / discharge state and... The output power of the diesel generator set is continuously adjusted according to the status to ensure that the diesel generator set operates in the high-efficiency range as much as possible, reduce energy loss, and can also be applied to energy management under multi-unit operating conditions. It is easy to implement and has broad application prospects in energy management of diesel-storage hybrid ships.

[0015] Other features and beneficial effects of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other beneficial effects of the invention can be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Unless otherwise specified, the positional relationships shown in the drawings in the following description are based on the direction in which the components are drawn in the figure.

[0017] Figure 1 A fuel characteristic curve of a diesel generator set provided in an embodiment of the present invention; Figure 2 A flowchart illustrating the steps of a multi-unit diesel storage energy management method according to an embodiment of the present invention; Figure 3 In one embodiment of the present invention, based on A schematic diagram showing the charging and discharging states divided by the power range; Figure 4 In another embodiment of the present invention, based on A schematic diagram showing the charging and discharging states divided by the power range; Figure 5 This is a schematic diagram illustrating the division of the number of diesel generators started based on the power range of the load power during charging, according to one embodiment of the present invention. Figure 6 This is a schematic diagram illustrating the division of the number of diesel generators started based on the power range of the load power during discharge, according to one embodiment of the present invention. Figure 7 The output power of the diesel generator and the charging and discharging waveforms of the energy storage battery under the multi-unit diesel energy management method provided in the embodiments of the present invention are shown. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that all terms used in this invention (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and should not be construed as limiting the invention; it should be further understood that the terms used in this invention should be understood to have the same meaning as those in the context of this specification and in the relevant field, and should not be understood in an idealized or overly formal sense, except as expressly defined in this invention.

[0020] In hybrid-electric marine systems, the fuel efficiency of diesel generator sets is related to the load rate, specifically as follows: Figure 1 The figure shown is an efficiency curve of a generator with respect to load rate and fuel consumption. Figure 1 It can be seen that fuel consumption is lower when the load rate is between 60% and 90%, meaning that the generator's typical high-efficiency range should be between 60% and 90% of the load rate. Of course, different diesel generators have different fuel efficiency curves; this study focuses on... Figure 1 Taking the generator as an example for analysis, the proposed method can be applied to other diesel generator sets.

[0021] It's also important to note that in energy storage modules, the energy storage battery absorbs electrical energy and converts it into chemical energy during charging, and releases energy during discharging, converting chemical energy back into electrical energy. Obviously, the energy conversion efficiency cannot be 100%. According to literature research, this conversion efficiency is approximately between 95% and 98%, and the higher the charging / discharging current, the lower the efficiency. Furthermore, the energy storage battery is connected to the grid via a power converter. Due to switching losses, conduction losses, and inductor magnetic and copper losses in the converter, the energy transfer efficiency of the converter cannot be 100%. That is, assuming the converter's unidirectional energy transfer efficiency is 1%, and the ratio of released to absorbed energy by the battery is 97%, then the efficiency of the energy effectively transferred to the load through the energy storage system is: (1-1%). (1-1%) 97% = 95%. With... Figure 1 Taking a diesel generator with the indicated fuel characteristics as an example, assuming the generator's fuel consumption in the high-efficiency range is 193g / kWh, considering the efficiency of the converter and battery, if energy is buffered by the battery, the actual fuel consumption is 193 / 0.95 = 203.1g / kWh, approximately equal to the fuel consumption at 50% load. In other words, when the diesel generator operates in its high-efficiency fuel range at a relatively optimal load rate, generating 1kWh of electricity consumes 193g of fuel. If an energy storage battery is used, due to energy conversion losses, the actual fuel consumption is 203g, which is comparable to the fuel consumption of a generator at 50% load without using an energy storage battery.

[0022] Therefore, it can be deduced that when the load rate is above 50%, using energy storage batteries to store energy has little effect on improving the efficiency of diesel generators, and may even reduce efficiency. In this case, the generator set should be allowed to directly supply power to the load. Energy storage batteries buffer energy, which only improves the operating efficiency of diesel generators in the low-power range. Based on the above derivation, the main inventive concept of the multi-unit diesel-electric energy storage management method provided by this invention is to avoid diesel generator sets operating in the low-efficiency range as much as possible, and correspondingly extend the proportion of their high-efficiency range.

[0023] Firstly, please refer to Figure 2 The following is a detailed description of a multi-unit diesel storage energy management method provided by an embodiment of the present invention.

[0024] In this embodiment, the multi-unit diesel energy storage management method is applied to a system with multiple diesel generator sets and energy storage batteries, and includes the following steps: S10, Real-time acquisition of the current status of the energy storage battery According to the above Determine the charge / discharge state of the energy storage battery.

[0025] The state of charge of the energy storage battery can be divided into multiple operating ranges, according to the aforementioned... The charging and discharging state of the energy storage battery is determined by the operating range. Of course, in this embodiment, the charging and discharging state can also be determined based on the current of the energy storage battery, relevant system commands, or relevant battery management modules.

[0026] Taking this embodiment as an example, according to the above Determining the charge / discharge state of the energy storage battery includes dividing the state of charge of the energy storage battery into multiple charge ranges, such as... Figure 3 As shown, the threshold for determining the power range includes at least the following: and ,and .

[0027] If the above In If the battery's charge range is within a certain range, then the energy storage battery is determined to be in a charging state, and the operating mode of the energy storage battery is switched to charging mode; if the In If the energy storage battery falls within a certain range, it is determined that the energy storage battery is in a discharging state, and the operating mode of the energy storage battery is switched to the discharging mode; if ... In If the energy range is within a certain range, it is determined that the energy storage battery maintains its current charging or discharging state, and the operating mode of the energy storage battery remains the current charging or discharging mode.

[0028] It should be noted that the above During charging and discharging, the value changes gradually in real time. Therefore, for the energy storage battery to maintain its current charging or discharging state means that when the... From charging mode The range of electricity consumption changes to During the specified energy range, the energy storage battery should remain in charging mode until the specified charging state is reached. Change to During the specified power range, the energy storage battery switches to discharge mode; when the... From the discharge mode The range of electricity consumption changes to During the specified charge range, the energy storage battery should remain in the discharge state of discharge mode until the specified discharge state is reached. Change to During the specified battery capacity range, the energy storage battery switches to charging mode.

[0029] It should also be noted that the energy storage battery's capacity range is not limited to three ranges. Depending on actual operating conditions, the energy storage battery's capacity range can be divided into other more detailed ranges, such as four, five, or six ranges, to meet the specific requirements of the energy storage battery. Precise control is required, but this embodiment is not limited thereto.

[0030] Furthermore, when the load encounters a situation requiring short-term high power demand, the aforementioned As demand constantly changes, the charging and discharging mode based on the aforementioned power range division requires increasing the number of charging and discharging cycles and frequent start-stop of diesel generator sets to supply the power required by the load. This can easily lead to problems such as high energy loss and reduced lifespan. For example, when a ship needs to perform operations such as entering and leaving port or avoiding collisions, the power required by the load will suddenly increase, thus requiring more charging and discharging cycles and frequent start-stop of diesel generator sets to supply the power required by the load.

[0031] To meet the power requirements of the load under conditions requiring short-term high power and effectively solve the above problems, in this embodiment, as follows: Figure 4 As shown, the threshold of the power range also includes and ,and ; When the In When the power range is within the specified range, determine the... and stated Size; if If the load power exceeds the rated power of the diesel generator set, the energy storage battery is determined to be in a discharging state, and its operating mode is switched to discharge mode. That is, when the load power exceeds the rated power of the diesel generator set, the energy storage battery is switched to discharge mode to compensate for the insufficient power of the diesel generator set, thereby reducing the number of charging and discharging cycles and the resulting frequent start-stop problems of the diesel generator. If so, it is determined that the energy storage battery maintains its current charging state or discharging state, and the operating mode of the energy storage battery maintains its current charging mode or discharging mode. When the In and When the energy range is within the specified range, it is determined whether the energy storage battery maintains its current charging or discharging state, and the operating mode of the energy storage battery remains the current charging or discharging mode.

[0032] It should also be noted that the aforementioned During charging and discharging, the value changes gradually in real time. Therefore, the statement that the energy storage battery maintains its current charging or discharging state here means that when the... Change from charging mode to or When the energy range is within the specified range, the energy storage battery remains in the charging state of the charging mode; when the... Change from discharge mode to or When the energy storage battery is within its discharge range, it remains in the discharge mode. Similarly, when the... From charging mode change to The power range and At that time, the energy storage battery remains in charging mode; when the aforementioned From discharge mode change to The power range and At that time, the energy storage battery still remains in discharge mode.

[0033] S20, determine the number of diesel generator sets to start based on the charging and discharging state of the energy storage battery; when the energy storage battery is charging, determine the number of diesel generator sets to start based on their rated power. and load power Determine the number of diesel generator sets to start; when the energy storage battery is in a discharging state, determine the maximum discharge power of the energy storage battery. The optimal power value of the diesel generator set Determine the number of diesel generator sets to be started.

[0034] Specifically, when there are multiple diesel generator sets, the number of diesel generator sets to be started is determined by the above-mentioned parameters, so as to more fully consider the energy distribution between the diesel generator sets and the energy storage batteries, and ensure that the number of diesel generator sets to be started can be increased or decreased more reasonably according to the load demand, thereby improving energy management efficiency.

[0035] This embodiment uses three diesel generator sets as an example for detailed explanation.

[0036] Please see Figure 5 When the energy storage battery is in a charging state, if If so, it is determined that a single diesel generator set is started and working; if If so, it is determined that the two diesel generator sets have started working; if If so, then it is determined that the three diesel generator sets mentioned above have started working; if the... Between and If the current number of diesel generator sets is maintained, then the number of such generator sets will remain unchanged. in, ;and , , , The calculation formula is: ; ; ; ; In the formula, 1.5 , , This is the hysteresis.

[0037] Preferably, this embodiment is preferred. Preferred Preferred .

[0038] in, The value of depends primarily on the losses of components such as the energy storage battery, converter, and switching devices mentioned in the aforementioned specification, as well as the high-efficiency power range of the diesel generator set; this embodiment is not limited to these. Figure 1 Taking a diesel generator with the indicated fuel characteristics as an example, based on relevant experience, the actual fuel consumption of the diesel generator is approximately equal to the fuel consumption at 50% load. Therefore, the preferred fuel type is... Furthermore, due to and To determine the power threshold between starting a single diesel generator set and starting two diesel generator sets, therefore, when multiple diesel generator sets are operating at the same power threshold... It should be twice. .Right now, The value of can be selected based on the actual power of the diesel generator set, choosing a parameter of 2 or close to 2. This embodiment is not limited to this. Additionally, the hysteresis... coefficient The value of can also be adjusted according to the actual operating conditions, and this embodiment is not limited thereto.

[0039] It should be noted that, due to It is a continuous value that changes in real time according to actual load demand, therefore Between and ], then maintaining the current number of diesel generator sets started means: when Starting and operating from a single diesel generator set Range change to During the interval, it will still maintain the operation of a single diesel generator set; when Start-up operation by two diesel generator sets Range change to During the interval, both diesel generator sets will continue to operate. Similarly, when Start-up operation by two diesel generator sets Range change to During the interval, both diesel generator sets will continue to operate; when Start-up and operation by three diesel generator sets Range change to During the interval, the operation of the three diesel generator sets will continue.

[0040] Through the above , Each is superimposed with a hysteresis To obtain , The method of determining these values ​​effectively avoids frequent start-stop cycles of the diesel generator set during power fluctuations, thus improving energy distribution efficiency. Furthermore, the selection of the aforementioned power thresholds ensures that... At lower levels, A smaller value makes it easier to start more diesel generators, allowing more energy to be transferred to the energy storage battery for charging.

[0041] Further, please refer to Figure 6 When the energy storage battery is in a discharged state, if If so, then it is determined that 0 of the aforementioned diesel generator sets have started working; if If so, it is determined that a single diesel generator set is started and working; if If so, it is determined that the two diesel generator sets have started working; if If so, then it is determined that the three diesel generator sets mentioned above have started working; if the... Between , and In between, the current number of diesel generator sets started remains unchanged; in, ;and , , , , , The calculation formula is: ; ; ; ; ; ; ; In the formula, , The value of can be adjusted according to the actual operating conditions, and this embodiment is not limited thereto; Hysteresis; the optimal power value of the diesel generator set. The value can be selected based on the optimal power value of the actual diesel generator set. Figure 1 Taking diesel generator sets as an example, It should be the load power value when the diesel generator set has the lowest combustion consumption.

[0042] With the above setup, during the discharge process of the energy storage battery, when the load power is relatively small, the energy storage battery alone provides power. When the load power is large, more diesel generator sets are gradually started, further improving energy distribution efficiency and reducing energy consumption. , , With hysteresis This is also related, and its function is to effectively avoid the problem of frequently starting and stopping the diesel generator set when power fluctuates by setting a hysteresis interval. For example, when Higher than Only one diesel generator set is started at a time, and when Below The diesel generator set is only shut down when necessary to ensure the stability of the generator count.

[0043] It should be noted that, due to It is a continuous value that changes in real time according to actual load demand, therefore, Between , and In between, maintaining the current number of diesel generator sets started means: when Starting and operating from 0 diesel generator sets Range change to During the interval, the number of diesel generator sets started and working remains at 0; when Starting and operating from a single diesel generator set Range change to During the interval, it will still operate as a single diesel generator set. Similarly, when Starting and operating from a single diesel generator set Range change to During the interval, it will still maintain the operation of a single diesel generator set; when Start-up operation by two diesel generator sets Range change to During the interval, both diesel generator sets will continue to operate. Start-up operation by two diesel generator sets Range change to During the interval, both diesel generator sets will continue to operate; when Starting and working from three diesel generator sets Range change to During the interval, the operation of the three diesel generator sets will continue.

[0044] It should also be noted that those skilled in the art can select fewer than three or more diesel generator sets according to actual needs, and make reasonable improvements using the above-mentioned inventive concept to apply the rules, formulas, and algorithms for the number of diesel generator sets to be started in other quantities, all of which fall within the protection scope of the embodiments of this disclosure.

[0045] S30, based on the charging and discharging state of the energy storage battery and the number of times the diesel generator set is started, determine the total output power of the diesel generator set. .

[0046] Specifically, based on the aforementioned analysis, even if the diesel generator set cannot operate in its high-efficiency range, as long as its power output is maintained at an efficiency of over 50%, it is still stronger than the output of the energy storage battery. Therefore, when the energy storage battery is charging, if the energy storage battery... If the power output is low, the diesel generator set should be able to produce a larger power output, while the energy storage battery... When the load is large, the diesel generator set should reduce its power output while ensuring that the output power is greater than the load power; conversely, when the energy storage battery discharges, the diesel generator set should increase its power output accordingly. Reduce power consumption while handling more power. That is, combine the power of the energy storage battery and the diesel generator with... This is related to enabling the efficient diesel generator to provide more power and reducing energy loss in the energy storage battery itself. Therefore, step S30 includes the following: When the energy storage battery is in a charging state, the total output power of the diesel generator set should be guaranteed. Higher than Excess power is absorbed by the energy storage battery, and The lower the SOC, the greater the power the diesel generator set should provide. Therefore, based on the SOC, the number of diesel generator sets started, and the... and the maximum power of the diesel generator set in its high-efficiency operating range. The minimum power of the diesel generator set in its high-efficiency operating range Determine the ; That is, the design described The calculation formula is: ; In the formula, The number of times the diesel generator set is started. for and The maximum value between the two. and These are the maximum and minimum power values ​​for the high-efficiency operating range of the diesel generator set, respectively. The specific values ​​can be set based on the actual fuel characteristics of the diesel generator. Figure 1 Taking a diesel generator with the indicated fuel characteristics as an example, the high-efficiency operating range of a diesel generator set can be defined as the area with a load rate between 60% and 90%. According to the above expression, when the energy storage battery... At that time, the total output power of the diesel generator set Maximum When energy storage batteries At that time, the total output power of the diesel generator set for That is, to ensure the total output power of the diesel generator set. Pick or The larger value in the range.

[0047] When the energy storage battery is in a discharging state, its discharge power can be set by comprehensively considering the load power and the operating conditions of the diesel generator set. That is, according to the... The above The current SOC value and the optimal power value of the diesel generator set. Determine the The aforementioned The following steps are included in the determination process: like If the diesel generator set does not work, The energy storage battery operates and discharges independently, and the total output power of the energy storage battery is... ; like Then the diesel generator set operates and discharges independently. When the energy storage battery is not working, the total output power of the energy storage battery is... ; like Then the diesel generator and the energy storage battery work simultaneously. Total output power of energy storage batteries - That is, each diesel generator maintains an output power of The remaining power is provided by energy storage batteries, and as... As the power decreases, the energy storage battery gradually provides less power.

[0048] It should be noted that the above calculation yields the total output power of all diesel generator sets; the reference output power for each generator is... .

[0049] In summary, it still has the following characteristics. Figure 1 Taking a diesel generator set with specific fuel characteristics as an example, the above-mentioned multi-unit diesel storage energy management method can achieve the following: Figure 7 The diagram shows the output power of the diesel generator and the charging / discharging waveforms of the energy storage battery. It reveals that the load power equals the sum of the diesel generator's output power and the total output power of the energy storage battery, achieving energy balance to meet load requirements. Throughout the operation, the diesel generator's output power remains within its rated range and is greater than 50%, mostly hovering around the 70% high-efficiency zone, indicating a high level of efficiency. The energy storage battery... Between 20% and 80%, it effectively avoids overcharging and over-discharging, and has a certain margin that can be reserved for emergency adjustments; the energy storage battery has fewer charge and discharge cycles, which is beneficial to improving battery life.

[0050] Secondly, the present invention also provides a multi-unit diesel-storage energy management system, comprising: The energy storage battery charge / discharge state determination module is used to determine the charge / discharge state of the energy storage battery in real time. Determine the charge / discharge state of the energy storage battery; The diesel generator set start quantity determination module is used to determine the start quantity of the diesel generator set based on the charging and discharging state of the energy storage battery; when the energy storage battery is in a charging state, it determines the start quantity based on the rated power of the diesel generator set. and load power Determine the number of diesel generator sets to start; when the energy storage battery is in a discharging state, determine the maximum discharge power of the energy storage battery. The optimal power value of the diesel generator set Determine the number of diesel generator sets to be started; The total output power determination module for the diesel generator set is used to determine the total output power of the diesel generator set based on the charging and discharging state of the energy storage battery and the number of diesel generator sets started. .

[0051] This energy management system not only achieves rational energy allocation under multi-unit operating conditions, improving energy utilization and saving energy consumption, but also effectively ensures the stability of system operation. It is easy to implement, highly versatile, and highly reliable, with broad application prospects. The specific functions, roles, and methods of each module can be found in the above-described method implementation examples, and will not be repeated here.

[0052] Thirdly, the present invention also provides a multi-unit diesel-storage system, including multiple diesel generator sets and energy storage batteries; the multiple diesel generator sets and the energy storage batteries are electrically connected to at least one load via a DC bus to supply power to the load; it also includes a multi-unit diesel-storage energy management method or a multi-unit diesel-storage energy management system as described in any of the above embodiments.

[0053] This system is also applicable to the rational allocation of energy under multi-unit operating conditions, improving energy utilization and effectively ensuring the performance of multi-unit diesel-storage systems, and has broad application prospects in diesel-storage hybrid ships. The specific functions, roles, and steps of its methods or systems can be referred to the embodiments of the first and second aspects mentioned above, and will not be repeated here.

[0054] In summary, the multi-unit diesel-storage energy management method, system, and system provided by this invention achieve a diesel-storage energy management strategy through three steps: determining the charge / discharge state of the storage battery, determining the number of diesel generator sets started, and determining the total output power of the diesel generator sets. This allows for energy management based not only on the charge / discharge state and... The output power of the diesel generator set is continuously adjusted according to the status to ensure that the diesel generator set operates in the high-efficiency range as much as possible, reduce energy loss, and can also be applied to energy management under multi-unit operating conditions. It is easy to implement and has broad application prospects in energy management of diesel-storage hybrid ships.

[0055] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of the present invention can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or the background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0056] Although this document frequently uses terms such as diesel generator set, energy storage battery, and power range, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention. The terms "first," "second," etc. (if present) in the specification, claims, and accompanying drawings of the embodiments of the invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for managing diesel-powered energy storage across multiple generating units, characterized in that, A system for use with multiple diesel generator sets and energy storage batteries includes the following steps: Real-time acquisition of the current status of the energy storage battery According to the above Determine the charge / discharge state of the energy storage battery; according to the Determining the charge / discharge state of the energy storage battery includes: The state of charge (SOC) of the energy storage battery is divided into multiple charge ranges, and the threshold values ​​for each charge range are determined to include at least the following: and ,and ; If the above In If the battery's charge range is within a certain range, then the energy storage battery is determined to be in a charging state, and the operating mode of the energy storage battery is switched to charging mode; if the In If the energy storage battery falls within a certain range, it is determined that the energy storage battery is in a discharging state, and the operating mode of the energy storage battery is switched to the discharging mode; if ... In If the energy range is within a certain range, it is determined that the energy storage battery maintains its current charging or discharging state, and the operating mode of the energy storage battery maintains its current charging or discharging mode. The threshold for the power range also includes and ,and ; When the In When the power range is within the specified range, determine the... and stated Size; if If the energy storage battery is in a discharging state, its operating mode is switched to discharge mode; if If so, it is determined that the energy storage battery maintains its current charging state or discharging state, and the operating mode of the energy storage battery maintains its current charging mode or discharging mode. When the In and When the energy range is within the specified range, it is determined whether the energy storage battery maintains its current charging state or discharging state, and the working mode of the energy storage battery remains the current charging mode or discharging mode. The number of diesel generator sets to be started is determined based on the charge / discharge state of the energy storage battery; when the energy storage battery is in a charging state, the number of starts is determined based on the rated power of the diesel generator set. and load power Determine the number of diesel generator sets to start; when the energy storage battery is in a discharging state, determine the maximum discharge power of the energy storage battery. The optimal power value of the diesel generator set Determine the number of diesel generator sets to be started; Based on the charge / discharge state of the energy storage battery and the number of diesel generator sets started, the total output power of the diesel generator sets is determined. .

2. The multi-unit diesel storage energy management method according to claim 1, characterized in that: The diesel generator set consists of three units; when the energy storage battery is charging, if If so, it is determined that a single diesel generator set is started and working; if If so, it is determined that the two diesel generator sets have started working; if If so, then it is determined that the three diesel generator sets mentioned above have started working; if the... Between and If the current number of diesel generator sets is maintained, then the number of such generator sets will remain unchanged. in, ;and , , , The calculation formula is: ； ； ； ； In the formula, 1.5 , , This is the hysteresis.

3. The multi-unit diesel storage energy management method according to claim 1, characterized in that: The diesel generator set consists of three units; When the energy storage battery is in a discharged state, if If so, then it is determined that 0 of the aforementioned diesel generator sets have started working; if If so, it is determined that a single diesel generator set is started and working; if If so, it is determined that the two diesel generator sets have started working; if If so, then it is determined that the three diesel generator sets mentioned above have started working; if the... Between , and In between, the current number of diesel generator sets started remains unchanged; in, ;and , , , , , The calculation formula is: ； ； ； ； ； ； ； In the formula, , This is the hysteresis.

4. The multi-unit diesel storage energy management method according to any one of claims 1-3, characterized in that, The total output power of the diesel generator set is determined based on the charge / discharge state of the energy storage battery and the number of times the diesel generator set is started. This includes the following steps: When the energy storage battery is in a charging state, based on the SOC, the number of diesel generator sets started, and the... and the maximum power of the diesel generator set in its high-efficiency operating range. The minimum power of the diesel generator set in its high-efficiency operating range Determine the ; When the energy storage battery is in a discharged state, according to the The above The SOC and the optimal power value of the diesel generator set. Determine the .

5. The multi-unit diesel storage energy management method according to claim 4, characterized in that, When the energy storage battery is in a charging state, The calculation formula is: ； In the formula, The number of times the diesel generator set is started.

6. The multi-unit diesel storage energy management method according to claim 5, characterized in that, When the energy storage battery is in a discharged state, The following steps are included in the determination process: like If the diesel generator set does not work, The energy storage battery operates independently, and the total output power of the energy storage battery is... ; like Then the diesel generator set operates independently. When the energy storage battery is not working, the total output power of the energy storage battery is... ; like Then the diesel generator and the energy storage battery work simultaneously. Total output power of energy storage batteries - .

7. A multi-unit diesel-electric energy storage management system, characterized in that, include: The energy storage battery charge / discharge state determination module is used to determine the charge / discharge state of the energy storage battery in real time. Determine the charge / discharge state of the energy storage battery; according to the Determining the charge / discharge state of the energy storage battery includes: The state of charge (SOC) of the energy storage battery is divided into multiple charge ranges, and the threshold values ​​for each charge range are determined to include at least the following: and ,and ; If the above In If the battery's charge range is within a certain range, then the energy storage battery is determined to be in a charging state, and the operating mode of the energy storage battery is switched to charging mode; if the In If the energy storage battery falls within a certain range, it is determined that the energy storage battery is in a discharging state, and the operating mode of the energy storage battery is switched to the discharging mode; if ... In If the energy range is within a certain range, it is determined that the energy storage battery maintains its current charging or discharging state, and the operating mode of the energy storage battery maintains its current charging or discharging mode. The threshold for the power range also includes and ,and ; When the In When the power range is within the specified range, determine the... and stated Size; if If the energy storage battery is in a discharging state, its operating mode is switched to discharge mode; if If so, it is determined that the energy storage battery maintains its current charging state or discharging state, and the operating mode of the energy storage battery maintains its current charging mode or discharging mode. When the In and When the energy range is within the specified range, it is determined whether the energy storage battery maintains its current charging state or discharging state, and the working mode of the energy storage battery remains the current charging mode or discharging mode. The diesel generator set start quantity determination module is used to determine the start quantity of the diesel generator set based on the charging and discharging state of the energy storage battery; when the energy storage battery is in a charging state, it determines the start quantity based on the rated power of the diesel generator set. and load power Determine the number of diesel generator sets to start; when the energy storage battery is in a discharging state, determine the maximum discharge power of the energy storage battery. The optimal power value of the diesel generator set Determine the number of diesel generator sets to be started; The total output power determination module for the diesel generator set is used to determine the total output power of the diesel generator set based on the charging and discharging state of the energy storage battery and the number of diesel generator sets started. .

8. A multi-unit diesel storage system, characterized in that: It includes multiple diesel generator sets and energy storage batteries; the multiple diesel generator sets and the energy storage batteries are electrically connected to at least one load via a DC bus to supply power to the load; it also includes a multi-generator diesel-storage energy management method as described in any one of claims 1-6, or a multi-generator diesel-storage energy management system as described in claim 7.

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