Ship multi-time scale energy management method

Abstract

The present application relates to a ship multi-time scale energy management system, a ship multi-time scale energy management method is designed, the demand meets power is obtained through a particle swarm algorithm, and there are two power distribution control methods according to the difference of the main power supply, one is that a diesel unit is used as the main power supply, and the other is that an energy storage unit is used, so that the maximum energy utilization is realized, the system cost is reduced while maintaining stability.

Description

Technical Field

[0001] This invention relates to the field of integrated energy management, which combines upper-level energy optimization scheduling, lower-level coordinated control, and intelligent algorithms, specifically a multi-timescale energy management method for ships. Background Technology

[0002] In recent years, distributed power generation modules composed of clean energy sources such as wind and solar power have been gradually applied to ships, forming shipboard microgrids. Meanwhile, integrated electric ships, characterized by electric propulsion systems, possess advantages such as rapid maneuverability, low noise, low fuel consumption, low maintenance costs, and high reliability, and have become an important direction for future ship development. Compared to traditional microgrids, shipboard microgrids often experience high-power propulsion system connections during navigation, causing short-term fluctuations in bus voltage due to sudden load changes. Since the load response characteristics of power generation units on multi-energy ships vary, uneven power distribution can lead to insufficient power supply. Therefore, it is urgent to rationally and effectively allocate ship power across both short-term and long-term time scales. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-timescale energy management method for ships. The multi-timescale energy management system of the ship, in which the method operates, includes a diesel generator unit, an energy storage unit, and a photovoltaic unit. The method includes: step S1, initializing all particles, and outputting the total power E at a certain load state time point of the diesel generator unit, energy storage unit, and photovoltaic unit. a As particles, the particle swarm is initialized with the operating state of the flexible load at each moment as unknowns. The individual extreme value pBest is set as the current position of the particle, and the swarm extreme value gBest is recorded, where pBest is the individual extreme value, representing the optimal total output power E of a single particle. a gBest is the swarm optimization, representing the optimal total output power E of the particle swarm. a Step S2: Determine the iteration number iter and the number of particles n, or directly obtain the optimal load state Gbest(n) of the system; Step S3: Based on the value of each particle in the system operating cost function F, change the individual extreme value pBest and the population extreme value gBest of the particles; Step S4: Set the load state power S of the nth particle... a (t) is output as the system's optimal load state Gbest(n), and F(gBest(n)) is output as the function to minimize the system operating cost F. min Output and end the calculation; and also includes: taking the system's optimal load state Gbest(n) in step S4 as the demand-compliant power P, and running two power distribution control methods under two modes, with the diesel unit as the main power source or the energy storage unit as the main power source, according to the demand-compliant power P.

[0004] Preferably, step S1 includes: step S11, calculating the load state power S of each particle at each moment of the flexible load. a (t); Step S12, based on the load state power S of each particle at each moment of the flexible load. a (t) Calculate the corresponding total output power E a Step S13, based on the calculated total output power E a The operating cost is calculated using the system operating cost function F; in step S14, based on the operating cost of each particle calculated in step S13, the optimal total output power E corresponding to a single particle in step S12 is... a Let pBest be the individual extreme value of a single particle; let E be the total optimal output power E obtained from searching all particles in step S12. a Let gBest be the population extremum of a single particle.

[0005] Preferably, step S2 includes: step S21 setting the maximum number of iterations and the maximum population size; step S22 starting from iteration number iter = 1 and particle number n = 1, iterating sequentially, and determining whether the number of iterations iter is less than the maximum number of iterations. If not, the optimal system load state Gbest(n) is obtained, and the process proceeds to step S4; if yes, the process proceeds to step S23; step S23, determining whether particle number n is less than the maximum population size; if not, updating the particle swarm, correcting the particle swarm to meet the load running time constraint, and returning to step S22 with iter = iter + 1; if yes, the process proceeds to step S3.

[0006] Preferably, step S3 includes: step S31, calculating the load state power S corresponding to the nth particle. a (t), calculate the system operating cost F(n) for the nth particle, where F(n) represents the operating cost of the nth particle; Step S32, determine whether F(n) is less than the operating cost F(pBest(n)) of the best fitness position among all positions experienced by the nth particle. If yes, set F(pBest(n)) = F(n) and proceed to step S33; if no, set the number of particles to n = n + 1 and return to step S23; Step S33, determine whether F(n) of the nth particle under step S32 is less than the operating cost F(gBest(n)) of the best fitness position found by all particles. If yes, set F(gBest(n)) = F(pBest(n)) and proceed to step S4; if no, set the number of particles n to n = n + 1 and return to step S23.

[0007] Preferably, the power distribution control method under the ship's multi-timescale energy management system with diesel generator units as the main power source includes: Step S5, taking the optimal load state Gbest(n) obtained in Step S4 as the demand-compliant power P; Step S6, determining whether the photovoltaic unit power Pv and the diesel generator unit power Pb are greater than or equal to the demand-compliant power P; if yes, proceed to Step S7; if no, the diesel generator unit, energy storage unit, and photovoltaic unit jointly supply power; Step S7, determining whether the photovoltaic unit power Pv is greater than or equal to the demand-compliant power P; if yes, the photovoltaic unit supplies power alone; if no, proceed to Step S8; Step S8, determining whether the photovoltaic unit power Pv is equal to 0; if yes, proceed to Step S9; if no, the photovoltaic unit and energy storage unit jointly supply power; Step S9, determining whether the SOC is greater than or equal to 20% and less than or equal to 80%; if yes, the energy storage unit supplies power alone; if no, the diesel generator unit supplies power alone.

[0008] Preferably, the power distribution control method under the ship's multi-timescale energy management system with energy storage units as the main power source includes: step S5', taking the system's optimal load state Gbest(n) obtained in step S4 as the demand-compliant power P; step S6', determining whether the photovoltaic unit power Pv and the energy storage unit power Pg are greater than or equal to the demand-compliant power P; if yes, proceed to step S7'; if no, the diesel unit, energy storage unit, and photovoltaic unit jointly supply power; step S7', determining whether the photovoltaic unit power Pv is greater than or equal to the demand-compliant power P; if yes, the photovoltaic unit supplies power alone; if no, proceed to step S8'; step S8', determining whether the photovoltaic unit power Pv is equal to 0; if yes, the diesel unit supplies power alone; if no, the photovoltaic unit and diesel unit supply power alone.

[0009] Preferably, the system operating cost function F is:

[0010] Where T is the number of time periods in the ship scheduling cycle, N is the number of power generation equipment types, is the power generation cost of equipment i at time t, and IR t Let P be the interruptibility cost at time t. i,t Let CO be the power output of device i at time t. i,t This represents the total system cost.

[0011] Total system cost CO i,t for:

[0012] CO i,t =CF i,t (P i,t )+IV i,t (P i,t )+OM i,t (P i,t )

[0013] Among them, CF i,t IV represents the fuel cost of diesel unit i at time t. i,t OM represents the depreciation cost of the energy storage unit or photovoltaic unit at time t. i,t The maintenance cost of device i at time t;

[0014] The depreciation expense IV i,t and maintenance costs OM i,t They are respectively:

[0015]

[0016] OM i,t =K m,i ×P i,t

[0017] Where d is the depreciation rate, m is the service life of the equipment, and C INSi,t Let P be the installation cost of device i at time t. r,i f is the rated power of device i. c,i Let K be the capacity factor of device i. m,i P represents the unit operating and maintenance cost of device i. i,t Let E be the power output of device i at time t, that is, the total output power E of the diesel unit, energy storage unit and photovoltaic unit at the load state time point of time t. a ;

[0018] Interruption fee IR t for:

[0019]

[0020] Where A, B, and C are coefficients for interruption costs, and P... IL This refers to the interruptible load.

[0021] Preferably, the total output power E of the diesel unit, energy storage unit, and photovoltaic unit at a certain load state time point is... a The calculation method is as follows: First, calculate the load-state power S of the diesel unit, energy storage unit, and photovoltaic unit. a (t);

[0022]

[0023] The second step is to calculate the total output power E. a :

[0024]

[0025] Where τ represents the load state time point, T a,s Indicates the earliest time the transferable load can begin. P represents the latest time that the transferable load will end. a For transferable load power, T a This refers to the operating time of the transferable load.

[0026] Preferably, the output power ω(s) of the diesel unit at a certain load state time point is calculated as follows: First, calculate the control coefficient M in the transfer function:

[0027] M = T j s 2 (1+Ts)+K(1+T2s)(1+T3s)

[0028] The second step is to calculate the output power ω(s) of the diesel unit under load conditions:

[0029]

[0030] Where K is the control increment in the transfer function, T is the delay time of the inertial element, T2 is the coefficient of the integral element, T3 is the coefficient of the derivative element, and ω ref (s) is the reference rotational speed, s is the Laplace complex parameter variable, and T e (s) is the sampling period, T j The generator's inertial time constant;

[0031] The output power P of the energy storage unit at a certain load state time point b The calculation method is as follows:

[0032] The first step is to calculate the voltage V of the energy storage unit. b for:

[0033] V b =E b -R b I b

[0034] The second step is to calculate the output power P. b :

[0035] P b =V b I b

[0036] Among them, E b I is the no-load electromotive force of the energy storage unit. b R is the output current of the energy storage unit. b The resistance is the internal resistance of the energy storage unit; the following is the output power P of the photovoltaic unit at a certain load state time point. V One calculation method: First, calculate the output current I of the photovoltaic unit. pv :

[0037]

[0038] The second step is to calculate the output power P of the photovoltaic unit under load conditions. V :

[0039] P V =I pv U pv

[0040] Among them: I sc U is the current of the photovoltaic unit. pv I0 is the output voltage of the photovoltaic unit, I0 is the reverse saturation current of the parasitic diode inside the photovoltaic unit, q is the electron charge, A is a constant coefficient, 1≤A≤2, k is the Boltzmann constant, T is the absolute temperature, and e is the natural constant.

[0041] Preferably, the SOC of the energy storage unit at a certain load state time point is calculated as follows:

[0042]

[0043] Among them, I b Q is the output current of the energy storage unit, and Q is the capacity of the energy storage unit.

[0044] The method for determining SOC is as follows:

[0045]

[0046] Among them, SOC i,t Let SOC represent the state of charge (SOC) of energy storage unit i at time t. i,t-1 The state of charge of energy storage unit i at time t-1. The output power of the energy storage unit. State of Charge (SOC) represents the charge and discharge state of the energy storage unit. i,min SOC i,max These are the lower and upper limits of the state of charge of energy storage unit i. E represents the discharge efficiency of the energy storage unit. i,BE Let i be the capacity of energy storage unit i. The charging efficiency of the energy storage unit is given by ΔT, where ΔT is the unit of time interval.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] First, this invention proposes a multi-timescale energy management method for ships to achieve efficient power balance between supply and demand while maintaining voltage and system stability.

[0049] Second, this invention aims at economic efficiency and energy conservation, and uses particle swarm optimization algorithm for optimization and regulation based on energy management.

[0050] Third, the particle swarm optimization algorithm based on this invention can calculate the operating cost corresponding to the local optimum, thereby greatly saving operating costs. By using the particle swarm optimization algorithm for optimization and adjustment, the operating cost of the system can be reduced. Attached Figure Description

[0051] Figure 1 The present invention provides a power distribution control method using a diesel unit as the main power source.

[0052] Figure 2 The present invention provides a power distribution control method using an energy storage unit as the main power source.

[0053] Figure 3 The flowchart of the particle swarm optimization algorithm provided by this invention is shown. Detailed Implementation

[0054] The technical content, structural features, objectives and effects of the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments.

[0055] A method for multi-timescale energy management of ships, wherein the method applies to a multi-timescale energy management system of ships, the system comprising a diesel unit, an energy storage unit, and a photovoltaic unit.

[0056] Since the power supply capacity, power supply status, and energy supply cost of the diesel unit, energy storage unit, and photovoltaic unit are all different, in order to obtain the optimal energy management path, the PSO algorithm (Particle Swarm Optimization) is used to obtain the required load power P, and two power distribution control methods are implemented based on the required load power P: one using the diesel unit as the main power source and the other using the energy storage unit as the main power source. This allows for the adjustment of the operating status of the diesel unit, energy storage unit, and photovoltaic unit during navigation.

[0057] The method outputs the total power E at a specific load state time point of the diesel unit, energy storage unit, and photovoltaic unit. a As particles, they include:

[0058] PSO regulation method and power distribution control method.

[0059] PSO adjustment methods are as follows: Figure 3 As shown, it includes:

[0060] Step S1: Initialize all particles.

[0061] Specifically, the particle swarm is initialized with the operating state of the flexible load at each moment as the unknown.

[0062] Step S11: Calculate the load state power S of each particle at each moment of the flexible load. a(t)(i.e., the load-state power S of the diesel unit, energy storage unit, and photovoltaic unit at the corresponding time) a (t)).

[0063] Step S12, based on the load state power S of each particle at each moment of the flexible load. a (t) Calculate the corresponding total output power E a .

[0064] Step S13: Based on the calculated total output power Ea, apply the system operating cost function. Calculate the system operating cost F.

[0065] Step S14: Based on the running cost of each particle calculated in step S13, the position with the best fitness among all the positions experienced by the individual particle obtained in step S12 is set as the current position of the individual particle, that is, the optimal total output power E of the individual particle. a The individual extreme value pBest is defined as the optimal position of all particles with the best fitness obtained in step S12, which is the optimal total output power E of the particle swarm. a The population extreme value is gBest.

[0066] Step S2: Calculate and determine the iteration number iter and the number of particles n, or directly obtain the optimal load state of the system Gbest(n).

[0067] Step S2 includes:

[0068] Step S21 sets the maximum number of iterations and the maximum population size.

[0069] Step S22 starts with iteration number iter=1 and particle number n=1, and iterates sequentially. It checks whether the number of iterations is less than or equal to the maximum number of iterations. If not, it outputs the optimal load state Gbest(n) of the system and proceeds to step S4; if yes, it proceeds to step S23.

[0070] Step S23: Determine if the number of particles n is less than the maximum population size; if not, update the particle swarm, correct the particle swarm to meet the running time constraints under the load state, and return to step S22 with the iteration number iter = iter + 1; if yes, proceed to step S3.

[0071] Step S3: Based on the iteration number iter and the number of particles n determined in step S2, calculate the value of each particle in the system operating cost function F (i.e., fitness), the individual extreme value pBest and the population extreme value gBest (i.e., the position and velocity of the updated particles).

[0072] Step S3 includes:

[0073] Step S31: Calculate the load state power S corresponding to the nth particle. a (t), calculate the system operating cost F(n) for the nth particle, where F(n) represents the operating cost for the nth particle.

[0074] Step S32: Determine whether F(n) is less than the running cost F(pBest(n)) of the best fitness position among all positions experienced by the nth particle. If yes, set F(pBest(n)) = F(n) and proceed to step S33; otherwise, count the number of particles as n = n + 1 and return to step S23.

[0075] Step S33: Determine whether F(n) of the nth particle in step S32 is less than the running cost F(gBest(n)) of the optimal fitness position found by all particles. If yes, set F(gBest(n)) = F(pBest(n)), i.e., make a substitution, and it is still equal to the aforementioned F(n); proceed to step S4; if no, count the number of particles n as n = n + 1, and return to step S23.

[0076] Step S4: Output the optimal load state Gbest(n) of the system, which is the load state power S calculated for the corresponding particle in step S31. a (t), output the minimum system operating cost function F. min This is F(gBest(n)) in step S33, and the operation ends.

[0077] As can be seen from the aforementioned method, the minimum system operating cost function F can be obtained from both steps S2 and S4 by obtaining the optimal system load state Gbest(n). min And the optimal load state Gbest(n).

[0078] like Figure 1 , Figure 2 As shown, after obtaining the optimal load state Gbest(n) of the system, it is counted as the system's required load power P. The power allocation control method of the ship's multi-timescale energy management system can adopt different strategies to maintain system stability based on different operating conditions of the ship. The ship's multi-timescale energy management system includes diesel generators, energy storage units, and photovoltaic units; the power allocation control method has two different allocation modes: one using the diesel generators as the main power source and the other using the energy storage units as the main power source.

[0079] When the diesel unit is used as the main power source, the power distribution control method includes:

[0080] Step S5: The optimal load state Gbest(n) of the system obtained from the PSO adjustment method is counted as the demand compliance power P.

[0081] Step S6: Determine whether the photovoltaic unit power Pv and the diesel engine unit power Pb are greater than or equal to the required power P; if yes, proceed to step S7; if no, the diesel unit, energy storage unit, and photovoltaic unit will jointly supply power.

[0082] Step S7: Determine whether the photovoltaic unit power Pv is greater than or equal to the required power P; if yes, the photovoltaic unit supplies power independently; if no, proceed to step S8.

[0083] Step S8: Determine if the photovoltaic unit power Pv is equal to 0; if yes, proceed to step S9; if no, the photovoltaic unit and the energy storage unit jointly supply power.

[0084] Step S9: Determine whether the SOC (State of Charge) of the energy storage unit is greater than or equal to 20% and less than or equal to 80%. If yes, the energy storage unit is powered separately; otherwise, the diesel unit is powered separately.

[0085] When the energy storage unit is used as the main power source, the power distribution control method includes:

[0086] Step S5': The optimal load state Gbest(n) of the system obtained from the PSO adjustment method is counted as the demand-compliant power P.

[0087] Step S6': Determine whether the power Pv of the photovoltaic unit and the power Pg of the energy storage unit are greater than or equal to the required power P; if yes, proceed to step S7'; if no, the diesel unit, energy storage unit, and photovoltaic unit will jointly supply power.

[0088] Step S7': Determine whether the photovoltaic unit power Pv is greater than or equal to the required power P; if yes, the photovoltaic unit supplies power independently; if no, proceed to step S8'.

[0089] Step S8': Determine whether the photovoltaic unit power Pv is equal to 0; if yes, the diesel unit is powered separately; if no, the photovoltaic unit and the diesel unit are powered separately.

[0090] In a specific embodiment, the following is the total output power E of the diesel unit, energy storage unit, and photovoltaic unit at a certain load state time point. a One calculation method:

[0091] The first step is to calculate the load-state power S of the diesel unit, energy storage unit, and photovoltaic unit. a (t).

[0092]

[0093] The second step is to calculate the total output power E. a .

[0094]

[0095] Where τ represents the load state time point, T a,s This represents the earliest time at which the transferable load can operate, and is a constant. P represents the latest time that the transferable load can operate, and is a variable. a For transferable load power, T a This refers to the runtime of the transferable load.

[0096] The following is one method for calculating the output power ω(s) of a diesel unit at a certain load state and time point:

[0097] The first step is to calculate the control coefficient M in the transfer function;

[0098] M = T j s 2 (1+Ts)+K(1+T2s)(1+T3s)

[0099] The second step is to calculate the output power ω(s) of the diesel unit under load conditions:

[0100]

[0101] Where K is the control increment in the transfer function, T is the delay time of the inertial element, T2 is the coefficient of the integral element, T3 is the coefficient of the derivative element, and ω ref (s) is the reference rotational speed, s is the Laplace complex parameter variable, and T e (s) is the sampling period, T j is the generator's inertial time constant.

[0102] The following is the output power P of the energy storage unit at a certain load state time point. b One calculation method:

[0103] The first step is to calculate the voltage V of the energy storage unit. b for.

[0104] V b =E b -R b I b

[0105] The second step is to calculate the output power P. b .

[0106] P b =V b I b

[0107] Among them, E b V is the no-load electromotive force of the energy storage unit. bI is the output voltage of the energy storage unit. b R is the output current of the energy storage unit. b This refers to the internal resistance of the energy storage unit.

[0108] In addition, the following is a method for calculating the State of Charge (SOC) of an energy storage unit at a certain load state time point, which is used to determine the state of charge of the energy storage unit.

[0109]

[0110] Where Q is the capacity of the energy storage unit.

[0111] The state of charge constraints of the energy storage unit are as follows:

[0112]

[0113] Among them, SOC i,t Let SOC represent the state of charge (SOC) of energy storage unit i at time t. i，t-1 The state of charge of energy storage unit i at time t-1. The output power of the energy storage unit. State of Charge (SOC) represents the charge and discharge state of the energy storage unit. i,min SOC i,max These are the lower and upper limits of the state of charge of energy storage unit i. E represents the discharge efficiency of the energy storage unit. i,BE Let i be the capacity of energy storage unit i. The charging efficiency of the energy storage unit is given by ΔT, where ΔT is the unit of time interval.

[0114] The following is the output power P of the photovoltaic unit at a certain load state time point. V One calculation method:

[0115] The first step is to calculate the output current I of the photovoltaic unit. pv ;

[0116]

[0117] The second step is to calculate the output power P of the photovoltaic unit under load conditions. V ;

[0118] P V =I pv U pv

[0119] Among them, I sc U is the current of the photovoltaic unit. pvI0 is the output voltage of the photovoltaic unit, I0 is the reverse saturation current of the parasitic diode inside the photovoltaic unit, q is the electron charge, A is a constant coefficient, 1≤A≤2, k is the Boltzmann constant, T is the absolute temperature, and e is the natural constant.

[0120] In a specific embodiment, the following is one function of the system operating cost function F.

[0121] In microgrids, the generation cost mainly considers operating costs and compensation costs for interruptible loads. Therefore, the system operating cost function F of the ship's power system can be expressed as:

[0122]

[0123] Where T is the number of time periods in the ship scheduling cycle, N is the number of power generation equipment types, is the power generation cost of equipment i at time t, and IR t Let P be the interruptibility cost at time t. i,t Let CO be the power output of device i at time t. i,t This represents the total system cost.

[0124] Since photovoltaic units are a green and pollution-free energy source, their fuel costs are not considered. Therefore, the total system cost can be expressed as:

[0125] CO i,t =CF i,t (P i,t )+IV i,t (P i,t )+OM i,t (P i,t )

[0126] Among them, CF i,t IV represents the fuel cost of diesel unit i at time t. i,t OM represents the depreciation cost of the energy storage unit or photovoltaic unit at time t. i,t Let t be the maintenance cost of device i at time t.

[0127] Among them, depreciation expense IV i,t and maintenance costs OM i,t They are represented as follows:

[0128]

[0129] OM i,t =K m,i ×P i,t

[0130] Where d is the depreciation rate, m is the service life of the equipment, and C INSi,t Let P be the installation cost of device i at time t. r,if is the rated power of device i. c,i Let K be the capacity factor of device i. m,i P represents the unit operating and maintenance cost of device i. i,t The power generation of device i at time t (i.e., the total output power of the diesel unit, energy storage unit, and photovoltaic unit). Ea ).

[0131] In cases of insufficient power supply during ship navigation, it is necessary to interrupt some non-critical loads to ensure the normal power supply to critical loads. The interruption costs are as follows:

[0132]

[0133] Where A, B, and C are coefficients for interruption costs, and P... IL This refers to the interruptible load.

[0134] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for energy management on ships across multiple time scales, characterized in that, The ship multi-timescale energy management system to which the method applies includes diesel units, energy storage units, and photovoltaic units; The method includes: Step S1: Initialize all particles and output the total power at a certain load state time point of the diesel unit, energy storage unit, and photovoltaic unit. As particles, the particle swarm is initialized with the operating state of the flexible load at each moment as unknowns. The individual extreme value pBest is set as the current position of the particle, and the swarm extreme value gBest is recorded, where pBest is the individual extreme value, representing the optimal total output power of a single particle. gBest is the swarm optimization, representing the optimal total output power of the particle swarm. ; Step S2: Determine the iteration number iter and the number of particles n, or directly obtain the optimal load state of the system Gbest(n). Step S3: Based on the value of the system operating cost function F for each particle, change the individual extreme value pBest and the population extreme value gBest of the particles. Step S4, calculate the load state power of the nth particle. As the output of the system's optimal load state Gbest(n), F(gBest(n)) is used as the function to minimize the system operating cost F. min Output the result and end the calculation; It also includes: taking the optimal load state Gbest(n) of the system in step S4 as the demand-compliant power P, and operating two power distribution control methods in two modes, with the diesel unit as the main power source or the energy storage unit as the main power source, according to the demand-compliant power P. Among them, the power distribution control method under the ship's multi-timescale energy management system, which uses diesel units as the main power source, includes: Step S5: The optimal load state Gbest(n) of the system obtained in step S4 is counted as the demand-compliant power P; Step S6: Determine whether the power of the photovoltaic unit and the power of the diesel engine unit are greater than or equal to the required power P; if yes, proceed to step S7; if no, the diesel unit, energy storage unit, and photovoltaic unit will jointly supply power. Step S7: Determine whether the power of the photovoltaic unit is greater than or equal to the required power P; if yes, the photovoltaic unit supplies power independently; if no, proceed to step S8. Step S8: Determine if the photovoltaic unit power is equal to 0; if yes, proceed to step S9; if no, the photovoltaic unit and the energy storage unit jointly supply power. Step S9: Determine whether the SOC is greater than or equal to 20% and less than or equal to 80%. If yes, the energy storage unit is powered separately; otherwise, the diesel unit is powered separately. Among them, the power distribution control method under the ship multi-timescale energy management system with energy storage units as the main power source includes: Step S5': The optimal load state Gbest(n) of the system obtained in step S4 is counted as the demand-compliant power P; Step S6': Determine whether the power of the photovoltaic unit and the power of the energy storage unit are greater than or equal to the required power P; if yes, proceed to step S7'; if no, the diesel unit, energy storage unit, and photovoltaic unit will jointly supply power. Step S7': Determine whether the power of the photovoltaic unit is greater than or equal to the required power P; if yes, the photovoltaic unit supplies power independently; if no, proceed to step S8'. Step S8': Determine if the photovoltaic unit power is equal to 0; if yes, the diesel unit is powered separately; if no, both the photovoltaic unit and the diesel unit are powered separately.

2. The method for multi-timescale energy management of ships according to claim 1, characterized in that, Step S1 includes: Step S11: Calculate the load state power of each particle at each moment of the flexible load. ; Step S12: Based on the load state power of each particle at each moment of the flexible load. Calculate the corresponding total output power ; Step S13, based on the calculated total output power Calculate the operating cost using the system operating cost function F; Step S14: Based on the operating cost of each particle calculated in step S13, calculate the optimal total output power corresponding to a single particle in step S12. Let pBest be the individual extreme value of a single particle; the optimal total output power obtained from searching all particles in step S12 is... Let gBest be the population extreme value for a single particle.

3. The method for multi-timescale energy management of ships according to claim 2, characterized in that, Step S2 includes: Step S21 sets the maximum number of iterations and the maximum population size; Step S22 starts with iteration number iter=1 and particle number n=1, and iterates sequentially. It checks whether the number of iterations iter is less than the maximum number of iterations. If not, the optimal system load state Gbest(n) is obtained, and proceeds to step S4; if yes, proceeds to step S23. Step S23: Determine if the number of particles n is less than the maximum population size; if not, update the particle swarm, correct the particle swarm to meet the load running time constraint, and return to step S22 with iter=iter+1; if yes, proceed to step S3.

4. The ship multi-timescale energy management method according to claim 3, characterized in that, Step S3 includes: Step S31: Calculate the load state power corresponding to the nth particle. Calculate the system operating cost F(n) for the nth particle, where F(n) represents the operating cost for the nth particle. Step S32: Determine whether F(n) is less than the running cost F(pBest(n)) of the best fitness position among all positions experienced by the nth particle. If yes, set F(pBest(n)) = F(n) and proceed to step S33; otherwise, count the number of particles as n = n + 1 and return to step S23. Step S33: Determine whether F(n) of the nth particle in step S32 is less than the running cost F(gBest(n)) of the optimal fitness position found by all particles. If yes, set F(gBest(n)) = F(pBest(n)) and proceed to step S4; otherwise, set the number of particles n to n = n + 1 and return to step S23.

5. A method for multi-timescale energy management of ships according to any one of claims 1 to 4, characterized in that, The system operating cost function F is: Where T is the number of time periods in the ship scheduling cycle, N is the number of types of power generation equipment, and t is the power generation cost of equipment i at time t. Let be the interruptibility cost at time t. Let be the power generation of device i at time t. This represents the total system cost. Total system cost for: in, Let be the fuel cost of diesel unit i at time t. This represents the depreciation cost of the energy storage unit or photovoltaic unit at time t. The maintenance cost of device i at time t; The depreciation expense and maintenance costs They are respectively: Where d is the depreciation rate and m is the service life of the equipment. Let i be the installation cost of device i at time t. The rated power of device i Let i be the capacity factor of device i. The unit operating and maintenance cost of equipment i. The power generation of device i at time t is the total output power of the diesel unit, energy storage unit, and photovoltaic unit under load conditions at time t. ; Interruption fees for: Where A, B, and C are coefficients for interruption costs. This refers to the interruptible load.

6. A method for multi-timescale energy management of ships according to any one of claims 1 to 4, characterized in that, The total output power of the diesel unit, energy storage unit, and photovoltaic unit at a certain load state time point. The calculation method is as follows: The first step is to calculate the load-state power of the diesel unit, energy storage unit, and photovoltaic unit. ; The second step is to calculate the total output power. : in, Indicates the load state at a specific time point. Indicates the earliest time the transferable load can begin. Indicates the latest time for the transferable load to end. For transferable load power, This refers to the operating time of the transferable load.

7. A method for multi-timescale energy management of ships according to any one of claims 1 to 4, characterized in that, The output power of the diesel unit at a certain load condition and time point The calculation method is as follows: The first step is to calculate the control coefficients in the transfer function. : Calculate the output power of the diesel unit under load. for: in, For control increment in the transfer function, For the delay time of the inertial element, The coefficients of the integral element, The coefficients of the differential element, For reference speed, For Laplace complex parameters, The sampling period is The generator's inertial time constant; The output power of the energy storage unit at a certain load state time point The calculation method is as follows: The first step is to calculate the voltage of the energy storage unit. for: The second step is to calculate the output power. : in, The no-load electromotive force of the energy storage unit. This is the output current of the energy storage unit. The internal resistance of the energy storage unit; The following is the output power of the photovoltaic unit at a certain load state time point. One calculation method: The first step is to calculate the output current of the photovoltaic unit. : The second step is to calculate the output power of the photovoltaic unit under load conditions. : in: The current of the photovoltaic unit, The output voltage of the photovoltaic unit. This refers to the reverse saturation current of the parasitic diode inside the photovoltaic unit. The amount of electron charge. The constant coefficient, , Where is Boltzmann's constant, and T is the absolute temperature. It is a natural constant.

8. A method for multi-timescale energy management of ships according to any one of claims 1 to 4, characterized in that, The SOC of the energy storage unit at a certain load state time point is calculated as follows: in, This is the output current of the energy storage unit. The capacity of the energy storage unit; The method for determining SOC is as follows: in, Let i be the state of charge of energy storage unit i at time t. The state of charge of energy storage unit i at time t-1. The output power of the energy storage unit. , This refers to the charging and discharging state of the energy storage unit. , These are the lower and upper limits of the state of charge of energy storage unit i. The discharge efficiency of the energy storage unit. Let i be the capacity of energy storage unit i. The charging efficiency of the energy storage unit. The unit of measurement is the time interval.

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