Inland river electric ship energy guarantee optimization method considering multiple energy supply modes

Abstract

The invention relates to the field of inland river electric ship energy complementation, in particular to an inland river electric ship energy guarantee optimization method considering multiple energy supply modes, which comprises the following steps: S1, collecting information, and establishing an inland river electric ship energy guarantee database; s2, establishing an inland river electric ship energy guarantee optimization model considering multiple energy supply modes; s3, converting the nonlinear inland river electric ship energy guarantee optimization model into a mixed integer linear programming model through a linearization technology; s4, substituting the database into the mixed integer linear programming model, solving an energy complementation decision variable with the lowest total energy complementation cost, and obtaining an inland river electric ship energy guarantee optimal strategy; and S5, scheduling the inland river electric ship energy guarantee optimization according to the inland river electric ship energy guarantee optimal strategy. The three energy supply modes of low-speed charging, quick charging and battery replacement are comprehensively applied, and the overall operation efficiency and economical efficiency of the electric ship in the inland river are considered.

Description

Technical Field

[0001] The present invention relates to the field of inland electric ship energy replenishment, and in particular to an inland electric ship energy guarantee optimization method taking into account multiple energy supply modes. Background Art

[0002] Inland waterway shipping is an important part of the integrated transportation system and water resource utilization. It is reported that more than 70% of inland waterway vessels in service are still at the level before the implementation of national emission regulations. The resulting pollutant emissions may have a significant negative impact on the air quality and health of residents in urban areas around ports. In order to cope with global challenges such as climate warming, environmental degradation, and energy crisis, it is imperative to reduce emissions from inland waterway shipping. The use of low-carbon / zero-carbon fuels and propulsion technologies to update inland waterway vessels is the most thorough way to reduce emissions and is an inevitable trend for the future development of green inland waterway shipping.

[0003] Since the current battery configuration is often unable to support a ship to complete a complete transportation mission, electric ships need to go to energy replenishment facilities for energy replenishment during navigation to ensure the energy required for navigation. Charging is a conventional energy supply mode, which is divided into slow charging and fast charging. Battery swapping is an emerging energy supply mode. Ships replenish electricity by replacing the depleted batteries on board with fully charged batteries at the battery swap station. Compared with charging, battery swapping can achieve faster energy replenishment, and the replacement time of a single battery is about 10-15 minutes. Most of my country's newly built electric ships support charging and battery swapping.

[0004] At present, the industry is mostly focused on the development of charging and swapping facilities for electric ships. Some scholars in the academic community are concerned about how to design low-cost energy security solutions for electric ships. However, focusing only on the application of a single energy supply mode loses the flexibility of mixed application of multiple energy supply modes. Referring to the experience and achievements in the field of electric vehicle energy security, in actual applications, no single energy supply mode can perform optimally in all cases, emphasizing the necessity of developing energy security solutions for electric ships by comprehensively using multiple energy supply modes.

[0005] In view of the above, we provide an energy security optimization method for inland electric ships taking into account multiple energy supply modes, and comprehensively use the three mainstream electric ship energy supply modes of slow charging, fast charging and battery replacement to provide energy security for ships, in order to improve the overall operating efficiency and economy of inland electric ships. Summary of the invention

[0006] In order to solve the technical problem that the prior art only uses a single energy supply mode and cannot take into account the overall operating efficiency and economy, the present invention proposes an energy security optimization method for inland electric ships taking into account multiple energy supply modes. By comprehensively using three electric ship energy supply modes of slow charging, fast charging and battery replacement, energy security is provided for the ship, taking into account the overall operating efficiency and economy of inland electric ships.

[0007] The technical solution of the present invention is:

[0008] An energy security optimization method for inland electric ships taking into account multiple energy supply modes, comprising:

[0009] Step S1, collect ship information, battery information, route information, charging and swapping station information, and establish an inland electric ship energy security database.

[0010] The ship information includes: overall length, width, depth, deadweight tonnage, capacity, design speed, water speed, water speed limit, rated motor power, propulsion power, and service power;

[0011] The battery information includes: battery capacity, battery quantity, battery pack specifications, charge and discharge rate, maximum charge and discharge power, minimum charge and discharge power, battery discharge efficiency, and comprehensive efficiency;

[0012] The route information includes: ports along the route, number of ports, number of segments, water speed of segments, length of segments, speed limit over ground, ports for cargo operations, and port call time;

[0013] The charging and battery swapping station information includes: slow charging station location, slow charging pile power, slow charging station rate, fast charging station location, fast charging pile power, fast charging station rate, battery swapping station location, unit battery swapping time, and battery swapping station rate.

[0014] Step S2, based on the actual application environment and needs, establish an energy security optimization model for inland electric ships taking into account multiple energy supply modes, including:

[0015] Step S201, based on the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement, establish an optimization objective function for the total cost of voyage energy replenishment.

[0016] The optimization objective function of the total cost of the voyage energy replenishment is:

[0017] C=C sc +C fc +C bs (1)

[0018] Where C is the total cost of voyage energy replenishment, C sc , C fc , C bsThey are the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement.

[0019] Step S202, based on the energy replenishment decision variables and the energy replenishment rate, respectively establish the functions of the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement.

[0020] The functions of the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement are:

[0021]

[0022] Where N represents the number of ports on the route that do not contain the replication node, and the replication node represents the return port other than the destination port; {2N-1} represents the replication node of the starting port; Respectively represent the set of ports with slow charging stations, fast charging stations, and battery swap stations on the route, excluding the starting port and its replication nodes; They represent port i, i.e. the i-th port that the ship passes through during the voyage, and the charging rates of slow charging, fast charging, and battery replacement charging technologies; are the energy replenishment decision variables, which represent the energy replenishment in the slow charging, fast charging and battery replacement modes of port i respectively.

[0023] Step S203, establishing a replenishment power constraint and a replenishment time constraint for the energy replenishment decision variables in step S202.

[0024] The supplementary power constraint is:

[0025]

[0026] In the formula, ΔE i is the amount of electricity replenished by the ship at port i, and ΔE1 is the amount of electricity replenished at the starting port; It is a collection of ports with charging and swapping stations on the route, except the starting port and its replication nodes.

[0027] The ship replenishes the power through slow charging at port i The constraints are:

[0028]

[0029] In the formula, E i is the power level of the ship when it arrives at port i, ΔSOC is the upper limit of the battery pack SOC max and lower limit SOC min The difference between them, CAP is the total capacity of a group of batteries, E max For electric ships, the SOC of all battery packs is SOC max Maximum power level at the time.

[0030] The ship is charged with electricity through fast charging at port i The constraints are:

[0031]

[0032] The amount of electricity replenished by the ship at port i through battery replacement The constraints are:

[0033]

[0034] Where N i is the number of battery packs replaced by the ship at port i; are the decision variables for the recharging port and mode, which respectively represent whether the ship performs slow charging, fast charging, or battery replacement at port i. If the ship enters the port and uses the corresponding energy supply mode for recharging, the value is 1, otherwise it is 0.

[0035] Among them, the number of battery packs replaced for the ship at port i is N i The constraints are:

[0036]

[0037] In the formula, is the maximum number of replaceable batteries when the ship arrives at port i, and ε is a sufficiently small number.

[0038] The energy replenishment time constraint is:

[0039]

[0040] In the formula, is the recharging time of port i; are the slow charging, fast charging and battery replacement time at port i, respectively, and the calculation method is:

[0041]

[0042] Where P sc and P fc For slow charging and fast charging power, The additional time for adding a port without cargo loading and unloading, t bs is the time required to replace a battery, m is the number of batteries in a group, N i is the number of battery packs replaced at port i; β i It is an indicator variable that represents whether only refueling operations are performed at port i. It takes 1 if only refueling operations are performed, and 0 otherwise.

[0043] Step S204, further establishing a replenishment mode selection constraint and a ship power constraint for the replenishment power in the supplementary power constraint in step S203.

[0044] The energy replenishment mode selection constraints include:

[0045] At most one energy supply mode can be selected in a port, and the expression is:

[0046]

[0047] After returning to the starting port, the ship is recharged to full power, expressed as:

[0048]

[0049] Some ports do not have fast charging or battery replacement stations, so the options for ships to recharge at these ports are limited. The expression is:

[0050]

[0051] The ship power constraints include:

[0052]

[0053] Where, E1 is the initial power level of the ship at the starting port; N b is the number of onboard batteries; η overall is the overall efficiency; ser is the service load power demand; P pro (v i-1 ) is the propulsion power load requirement on the route from port i-1 to port i; η dc is the battery pack discharge efficiency; {1} indicates the starting port.

[0054] Step S205, for the recharging time in the recharging time constraint in step S203, further establish a round trip time constraint and a charging and discharging power constraint.

[0055] The round trip time constraints of the voyage are:

[0056] T total ≤T total,max (8)

[0057] Where, T total is the round trip time of the voyage, T total,max is the maximum round trip time of the voyage;

[0058] The calculation formula for the round trip time of the voyage is:

[0059]

[0060] In the formula, is a collection of ports on the route; is the port time of port i; is the recharging time of port i; is the flight time of segment j;

[0061] The calculation method of the flight time is:

[0062]

[0063] In the formula, len j is the length of segment j; v j is the ship’s speed over water on segment j, w j is the water velocity of segment j, v j +w j is the ship’s speed over the ground on segment j; A collection of flight segments on a route.

[0064] The constraints on water speed are:

[0065]

[0066] The ground speed constraint is:

[0067]

[0068] In the formula, are the minimum and maximum ground speed limits for segment j; are the minimum and maximum water speed limits for segment j.

[0069] The charge and discharge power constraints are:

[0070]

[0071] In the formula, is the lower limit of battery pack discharge power, The upper limit of the battery pack discharge power;

[0072] The charging power constraints for slow charging and fast charging are:

[0073]

[0074] In the formula, is the rated charging power of the slow charging pile. is the rated charging power of the fast charging pile, The upper limit of charging power for the onboard battery pack.

[0075] Step S3, converting the nonlinear inland electric ship energy security optimization model constructed in step S2 into a mixed integer linear programming model through linearization technology.

[0076] The linearization techniques include:

[0077] Step S301, the nonlinearity caused by the max function is linearized by introducing an intermediate quantity and the large M method:

[0078] The intermediate quantity includes the indicator variable z sc , z fc and intermediate variables The relationship between the indicator variable and the intermediate variable is:

[0079]

[0080] The equivalent linear expressions of equations (9) and (10) containing the max function are:

[0081]

[0082] In the formula, the intermediate variable Represent the max function in equations (9) and (10) respectively; indicator variable z sc , z fc It is a 0-1 variable, indicating the value selection of the max function;

[0083] Step S302, linearize the nonlinearity caused by 0-1 variables using the Big M method:

[0084] The equivalent expression of formula (22) containing 0-1 variables is:

[0085]

[0086] The equivalent expression of formula (18) containing 0-1 variables is:

[0087]

[0088] Formula (19) is equivalent to:

[0089]

[0090] Step S4, substituting the database established in step S1 into the mixed integer linear programming model obtained in step S3, solving the energy replenishment decision variables with the lowest total energy replenishment cost for the voyage, and obtaining the optimal energy guarantee strategy for inland electric ships;

[0091] Step S5, according to the inland electric vessel energy security optimal strategy, the inland electric vessel energy security optimization is scheduled, and the scheduling includes: determining the energy replenishment port, determining the energy supply mode, and determining the replenishment energy of each port.

[0092] The present invention provides energy guarantee for ships by comprehensively utilizing three energy supply modes, namely slow charging, fast charging and battery replacement, while taking into account the overall operating efficiency and economy of inland electric ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 The present invention is a flow chart of an energy security optimization method for inland electric ships taking into account multiple energy supply modes.

[0094] Figure 2 It is an energy guarantee scheme for inland electric ships under a single energy supply mode in an embodiment of the present invention to replenish energy at each port.

[0095] Figure 3 It is the energy replenishment cost of each port in the energy guarantee scheme for inland electric ships under the single energy supply mode in the embodiment of the present invention.

[0096] Figure 4 It is the energy replenishment time of each port in the energy guarantee scheme of inland electric ships under the single energy supply mode in the embodiment of the present invention.

[0097] Figure 5 This is an energy guarantee scheme for inland electric ships taking into account multiple energy supply modes in an embodiment of the present invention. DETAILED DESCRIPTION

[0098] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0099] The present invention provides an energy guarantee optimization method for inland electric ships taking into account multiple energy supply modes, the process is as follows: Figure 1 As shown, the following steps are included:

[0100] Step S1: Collect ship information, battery information, route information, charging and swapping station information, etc., and establish an inland electric ship energy security database;

[0101] The energy guarantee database of the inland electric ship is shown in Table 1:

[0102] Table 1 Energy security database for inland electric ships

[0103]

[0104]

[0105] Step S2: According to the actual application environment and needs, an energy security optimization model for inland electric ships taking into account various energy supply modes is established.

[0106] Step S201: Based on the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement, an optimization objective function of the total cost of voyage energy replenishment is established, which is defined as shown in formula (1):

[0107] C=C sc +C fc +C bs (1)

[0108] Where C is the total cost of voyage energy replenishment, C sc , C fc , C bs They are the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement.

[0109] Step S202: Based on the energy replenishment decision variables and the energy replenishment rate, the functions of the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement are established respectively.

[0110] The functions of the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement are shown in equations (2)-(4):

[0111]

[0112] Where N represents the number of ports on the route including the departure port and the destination port, excluding the duplicate node (the port on the return voyage, excluding the destination port. For example, Port A is a port on the route, Port A on the outbound voyage is called Port A, and Port A on the return voyage is called the duplicate node of Port A.); Respectively represent the set of ports with slow charging stations, fast charging stations, and battery swap stations on the route, including the replication nodes, excluding the starting port and its replication nodes; {2N-1} represents the replication node of the starting port; They represent the slow charging, fast charging and battery replacement rates of port i respectively; They respectively represent the energy replenishment in port i slow charging, fast charging and battery replacement modes.

[0113] Step S203: for the energy replenishment decision variables in step S202, establish a replenishment power constraint and an energy replenishment time constraint.

[0114] 1) Supplementary power constraints:

[0115]

[0116] Where ΔE i is the amount of electricity replenished by the ship at port i, and ΔE1 is the amount of electricity replenished at the starting port; It is a collection of ports with charging and swapping stations on the route, except the starting port and its replication nodes.

[0117] The ship replenishes the power through slow charging at port i The constraints are:

[0118]

[0119] In the formula, E i is the power level of the ship when it arrives at port i, ΔSOC is the upper limit of the battery pack SOC max and lower limit SOC minThe difference between them, CAP is the total capacity of a group of batteries, E max For electric ships, the SOC of all battery packs is SOC max Maximum power level at the time.

[0120] The ship is charged with electricity through fast charging at port i The constraints are:

[0121]

[0122] The amount of electricity replenished by the ship at port i through battery replacement The constraints are:

[0123]

[0124] Where N i is the number of battery packs replaced by the ship at port i; are the decision variables for the recharging port and mode, which respectively represent whether the ship performs slow charging, fast charging, or battery replacement at port i. If the ship enters the port and uses the corresponding energy supply mode for recharging, the value is 1, otherwise it is 0.

[0125] Among them, it is stipulated that only battery packs that have reached the lower limit of the state of charge (SOC) can be replaced, and further N i There are constraints as shown in equations (21) and (22).

[0126]

[0127] In the formula, is the maximum number of replaceable batteries when the ship arrives at port i, and ε is a sufficiently small number.

[0128] 2) Recharge time constraints:

[0129]

[0130] In the formula, is the recharging time of port i; are the slow charging, fast charging and battery replacement time at port i, respectively, and the calculation method is:

[0131]

[0132] Where P sc and P fc For slow charging and fast charging power, The additional time for adding a port without cargo loading and unloading, t bs is the time required to replace a battery, m is the number of batteries in a group, N i is the number of battery packs replaced at port i; β iIt is an indicator variable that represents whether only refueling operations are performed at port i. It takes 1 if only refueling operations are performed, and 0 otherwise.

[0133] Step S204: for the replenishment power in the supplementary power constraint in step S203, further establish a replenishment mode selection constraint and a ship power constraint.

[0134] 1) Constraints on energy replenishment mode selection:

[0135] Inland electric ships can only choose one energy supply mode at most in a port, which is specifically expressed as shown in formula (14):

[0136]

[0137] In addition, when the ship returns to the starting port, in order to ensure the initial energy for the next voyage, the ship needs to be restored to a fully charged state, as shown in formula (15):

[0138]

[0139] Considering that not all ports have fast charging and battery replacement technologies, ships are limited in their choices at these ports. The specific expressions are shown in equations (16) and (17):

[0140]

[0141] 2) Ship power constraints:

[0142]

[0143] Where, E1 is the initial power level of the ship at the starting port; N b is the number of onboard batteries; η overall is the overall efficiency; ser is the service load power demand; P pro (v i-1 ) is the propulsion power load requirement on the route from port i-1 to port i; η dc is the battery pack discharge efficiency; {1} indicates the starting port.

[0144] Step S205: For the recharging time in the recharging time constraint in step S203, further establish a round trip time constraint and a charging and discharging power constraint.

[0145] 1) Voyage round trip time constraints:

[0146] T total ≤T total,max (8)

[0147] Where, T total is the round trip time of the voyage, T total,maxis the maximum round trip time of the voyage;

[0148] The calculation formula for the round trip time of the voyage is:

[0149]

[0150] In the formula, is a collection of ports on the route; is the port time of port i; is the recharging time of port i; is the flight time of segment j;

[0151] The calculation method of the voyage time is:

[0152]

[0153] In the formula, len j is the length of segment j; v j is the ship’s speed over water on segment j, w j is the water velocity of segment j, v j +w j is the ship’s speed over the ground on segment j; A collection of flight segments on a route.

[0154] The constraints on water speed are:

[0155]

[0156] The ground speed constraint is:

[0157]

[0158] In the formula, are the minimum and maximum ground speed limits for segment j; are the minimum and maximum water speed limits for segment j.

[0159] 2) The charge and discharge power constraints are:

[0160]

[0161] In the formula, is the lower limit of battery pack discharge power, The upper limit of the battery pack discharge power;

[0162] The charging power constraints for slow charging and fast charging are:

[0163]

[0164] In the formula, is the rated charging power of the slow charging pile. is the rated charging power of the fast charging pile, The upper limit of charging power for the onboard battery pack.

[0165] Step S3: converting the nonlinear inland electric ship energy security optimization model constructed in step S2 into a mixed integer linear programming model through linearization technology.

[0166] The linearization techniques include:

[0167] Step S301: The nonlinearity caused by the max function is linearized by introducing an intermediate quantity and the large M method:

[0168] The intermediate quantity includes the indicator variable z sc , z fc and intermediate variables The relationship between the indicator variable and the intermediate variable is:

[0169]

[0170]

[0171] The equivalent linear expressions of equations (9) and (10) containing the max function are:

[0172]

[0173] In the formula, the intermediate variable Represent the max function in equations (9) and (10) respectively; indicator variable z sc , z fc It is a 0-1 variable, indicating the value selection of the max function;

[0174] Step S302: For the nonlinearity caused by 0-1 variables, linearization is performed using the Big M method:

[0175] Formula (22) contains the multiplication of 0-1 variables and integer variables, and the equivalent expression is:

[0176]

[0177] In formulas (18) and (19), there are integer variables and 0-1 variables Multiplying, there is a continuous variable E i and 0-1 variables Multiplication can be linearized using the Big M method.

[0178] The equivalent expression of formula (18) is:

[0179]

[0180] The equivalent expression of formula (19) is:

[0181]

[0182]

[0183] Step S4: Substituting the database established in step S1 into the mixed integer linear programming model obtained in step S3, solving the energy replenishment decision variables with the lowest total energy replenishment cost for the voyage, and obtaining the optimal energy guarantee strategy for inland electric ships;

[0184] Step S5: according to the optimal strategy for energy security of the inland electric vessel, the energy security of the inland electric vessel is optimized and scheduled, and the scheduling includes: determining the energy replenishment port, determining the energy supply mode, and determining the energy replenishment of each port.

[0185] Based on the relevant data of COSCO SHIPPING Green Water 01 700TEU pure electric container ship sailing on the Wuhan-Yangshan route, four energy guarantee schemes for inland electric ships using a single energy supply mode and the method of the present invention are analyzed and compared.

[0186] The four options are:

[0187] 1) Energy security solution for inland electric ships based on slow charging;

[0188] 2) Energy security solution for inland electric ships based on fast charging;

[0189] 3) Energy security solution for inland electric ships based on battery replacement;

[0190] 4) Energy security solutions for inland electric ships based on multiple energy supply modes.

[0191] For schemes 1-3 using a single energy supply mode, the energy guarantee scheme with the lowest cost is as follows: Figure 2 , Figure 3 , Figure 4 shown.

[0192] Comparing the energy guarantee solutions with the shortest time and lowest cost in these three modes, slow charging has the lowest total cost, but due to the low energy replenishment efficiency, it is difficult to meet the huge energy replenishment needs of electric ships, and the voyage time reaches nearly 1,500 hours. The energy replenishment time of battery swapping is significantly lower than slow charging and fast charging, and a round trip can be completed in less than 250 hours, but the cost is also higher than the other two modes. In summary, among the three energy replenishment modes, slow charging and fast charging are better from a cost perspective; from an efficiency perspective, battery swapping and fast charging are better.

[0193] Scheme 4 is the lowest cost scheme under the condition that the voyage time is limited to 300 hours. The energy guarantee scheme is as follows: Figure 5 As shown in the figure, it can be seen that ships mainly choose two energy supply modes: fast charging and battery replacement.

[0194] A comprehensive comparison of the four schemes is shown in Table 2. It can be seen that the inland ship energy guarantee scheme taking into account multiple energy supply modes can achieve a balance between cost and efficiency to a certain extent, and reduce costs while ensuring efficiency. Compared with schemes 1 and 2, the efficiency is improved by 80.5% and 56.4%. Compared with scheme 3, the cost is reduced by 3.1%.

[0195] Table 2 Comparison of optimization results of different schemes

[0196] plan Total energy replenishment cost (10,000 yuan) Total time (hours) 1 21.37 1499 2 33.26 671 3 44.44 249 4 43.06 292

[0197] It should be noted that the above-described specific implementations can enable those skilled in the art to more fully understand the invention, but do not limit the invention in any way. Therefore, although this specification has described the invention in detail with reference to the drawings and embodiments, those skilled in the art should understand that the invention can still be modified or replaced by equivalents. In short, all technical solutions and improvements that do not deviate from the spirit and scope of the invention should be included in the protection scope of the patent for the invention.

Claims

1. A method for optimizing energy security of inland electric ships taking into account multiple energy supply modes, characterized in that: Step S1, collecting ship information, battery information, route information, and charging and swapping station information to establish an inland electric ship energy security database; Step S2, based on the actual application environment and needs, establish an energy security optimization model for inland electric ships taking into account multiple energy supply modes, including: Step S201, based on the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement, an optimization objective function of the total cost of voyage energy replenishment is established; Step S202, based on the energy replenishment decision variables and the energy replenishment rate, respectively establish the functions of the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement; Step S203, establishing a replenishment power constraint and a replenishment time constraint for the energy replenishment decision variable in step S202; Step S204, further establishing a replenishment mode selection constraint and a ship power constraint for the replenishment power in the supplementary power constraint in step S203; Step S205, for the recharging time in the recharging time constraint in step S203, further establishing a round trip time constraint and a charging and discharging power constraint; Step S3, converting the nonlinear inland electric ship energy security optimization model constructed in step S2 into a mixed integer linear programming model through linearization technology; Step S4, substituting the database established in step S1 into the mixed integer linear programming model obtained in step S3, solving the energy replenishment decision variables with the lowest total energy replenishment cost for the voyage, and obtaining the optimal energy guarantee strategy for inland electric ships; Step S5, according to the inland electric ship energy security optimal strategy, the inland electric ship energy security optimization is scheduled, and the scheduling includes: determining the energy replenishment port, determining the energy supply mode, and determining the replenishment energy of each port.

2. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 1 is characterized in that: In the step S1, The ship information includes: overall length, width, depth, deadweight tonnage, capacity, design speed, water speed, water speed limit, rated motor power, propulsion power, and service power; The battery information includes: battery capacity, battery quantity, battery pack specifications, charge and discharge rate, maximum charge and discharge power, minimum charge and discharge power, battery discharge efficiency, and comprehensive efficiency; The route information includes: ports along the route, number of ports, number of segments, water speed of segments, length of segments, speed limit over ground, ports for cargo operations, and port call time; The charging and battery swapping station information includes: slow charging station location, slow charging pile power, slow charging station rate, fast charging station location, fast charging pile power, fast charging station rate, battery swapping station location, unit battery swapping time, and battery swapping station rate.

3. The energy guarantee optimization method for inland electric ships taking into account multiple energy supply modes according to claim 1 is characterized in that: In step S201, the optimization objective function of the total cost of the voyage energy replenishment is: C=C sc +C fc +C bs (1) Where C is the total cost of voyage energy replenishment, C sc , C fc , C bs They are the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement.

4. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 1 is characterized in that: In step S202, the functions of the total cost of slow charging, the total cost of fast charging, and the total cost of battery replacement are respectively: Where N represents the number of ports on the route that do not contain the replication node, and the replication node represents the return port other than the destination port; {2N-1} represents the replication node of the starting port; Respectively represent the set of ports with slow charging stations, fast charging stations, and battery swap stations on the route, excluding the starting port and its replication nodes; They represent port i, i.e. the i-th port that the ship passes through during the voyage, and the charging rates of slow charging, fast charging, and battery replacement charging technologies; are the energy replenishment decision variables, which represent the energy replenishment in the slow charging, fast charging and battery replacement modes of port i respectively.

5. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 1 is characterized in that: In step S203, the supplementary power constraint is: In the formula, ΔE i is the amount of electricity replenished by the ship at port i, and ΔE1 is the amount of electricity replenished at the starting port; It is the set of ports with charging and swapping stations on the route, except the starting port and its replication nodes; The ship replenishes the power through slow charging at port i The constraints are: In the formula, E i is the power level of the ship when it arrives at port i, ΔSOC is the upper limit of the battery pack SOC max and lower limit SOC min The difference between them, CAP is the total capacity of a group of batteries, E max For electric ships, the SOC of all battery packs is SOC max Maximum power level at 100 Hz; The ship is charged with electricity through fast charging at port i The constraints are: The amount of electricity replenished by the ship at port i through battery replacement The constraints are: Where N i is the number of battery packs replaced by the ship at port i; are the decision variables for the recharging port and mode, which respectively represent whether the ship performs slow charging, fast charging, or battery replacement at port i. If the ship enters the port and uses the corresponding energy supply mode for recharging, the value is 1, otherwise it is 0.

6. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 5 is characterized in that: The number of battery packs N replaced for the ship at port i i The constraints are: In the formula, is the maximum number of replaceable batteries when the ship arrives at port i, and ε is a sufficiently small number.

7. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 1 is characterized in that: In step S203, the energy replenishment time constraint is: In the formula, is the recharging time of port i; are the slow charging, fast charging and battery replacement time at port i, respectively, and the calculation method is: Where P sc and P fc For slow charging and fast charging power, The additional time for adding a port without cargo loading and unloading, t bs is the time required to replace a battery, m is the number of batteries in a group, N i is the number of battery packs replaced at port i; β i It is an indicator variable that represents whether only refueling operations are performed at port i. It takes 1 if only refueling operations are performed, and 0 otherwise.

8. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 1 is characterized in that: In step S204, the energy replenishment mode selection constraint includes: At most one energy supply mode can be selected in a port, and the expression is: After returning to the starting port, the ship is recharged to full power, expressed as: Some ports do not have fast charging or battery replacement stations, so the options for ships to recharge at these ports are limited. The expression is:

9. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 1, characterized in that: In step S204, the ship power constraint includes: Where, E1 is the initial power level of the ship at the starting port; N b is the number of onboard batteries; η overall is the overall efficiency; ser is the service load power demand; P pro (v i-1 ) is the propulsion power load requirement on the route from port i-1 to port i; η dc is the battery pack discharge efficiency; {1} indicates the starting port.

10. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 1, characterized in that: In step S205, the round trip time constraint of the voyage is: T total ≤T total,max (8) Where, T total is the round trip time of the voyage, T total,max is the maximum round trip time of the voyage; The calculation formula for the round trip time of the voyage is: In the formula, is a collection of ports on the route; is the port time of port i; is the recharging time of port i; is the flight time of segment j; The calculation method of the flight time is: In the formula, len j is the length of segment j; v j is the ship’s speed over water on segment j, w j is the water velocity of segment j, v j +w j is the ship’s speed over the ground on segment j; A collection of flight segments on a route.

11. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 8, characterized in that: The constraints on water speed are: The ground speed constraint is: In the formula, are the minimum and maximum ground speed limits for segment j; are the minimum and maximum water speed limits for segment j.

12. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 1, characterized in that: In step S205, the charge and discharge power constraints are: In the formula, is the lower limit of battery pack discharge power, The upper limit of the battery pack discharge power; The charging power constraints for slow charging and fast charging are: In the formula, is the rated charging power of the slow charging pile. is the rated charging power of the fast charging pile, The upper limit of charging power for the onboard battery pack.

13. The method for optimizing energy security of inland electric ships taking into account multiple energy supply modes according to claim 1, characterized in that: In step S3, the linearization technique includes: Step S301, the nonlinearity caused by the max function is linearized by introducing an intermediate quantity and the large M method: The intermediate quantity includes the indicator variable z sc , z fc and intermediate variables The relationship between the indicator variable and the intermediate variable is: The equivalent linear expressions of equations (9) and (10) containing the max function are: In the formula, the intermediate variable Represent the max function in equations (9) and (10) respectively; indicator variable z sc , z fc It is a 0-1 variable, indicating the value selection of the max function; Step S302, linearize the nonlinearity caused by 0-1 variables using the Big M method: The equivalent expression of formula (22) containing 0-1 variables is: The equivalent expression of formula (18) containing 0-1 variables is: Formula (19) is equivalent to:

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