A ship power grid dispatching method

Abstract

The present invention discloses a method for dispatching a faulty ship power grid that takes mobile energy storage into account. The method first investigates basic data on daytime sunlight intensity and ship load, then establishes models of diesel generators and solar photovoltaic power generation systems. Furthermore, the temporal and spatial transfer and charge-discharge characteristics of the mobile energy storage are quantitatively analyzed, and a mobile energy storage operation model is formulated. On this basis, a daytime dispatching model for the faulty ship power grid is constructed with the goal of minimizing the daily fuel consumption of the diesel generator. Finally, the dispatching model is linearized as a mixed-integer linearization problem and solved using CPLEX. The faulty ship power grid dispatching scheme proposed in this patent application fully considers the scenario of ship power line failures. By utilizing mobile energy storage to communicate between the power source and the load, it not only achieves power transmission but also reduces fuel consumption during ship operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of renewable energy power generation scheduling, and in particular relates to a ship power grid scheduling strategy taking into account mobile energy storage failures. Background Art

[0002] Currently, ship electrification is an emerging trend in the shipping industry. Energy storage batteries have become a crucial component of the ship's electrical grid on many newly launched vessels. Furthermore, some ships are equipped with solar photovoltaic panels, which can provide power during periods of intense sunlight, thereby reducing fuel consumption by diesel generators. Under normal circumstances, the coordinated operation of diesel generators, energy storage batteries, and photovoltaic power generation systems enables ships to sail economically.

[0003] However, when a ship is sailing on the open ocean and encounters a storm that destroys the ship's power grid or aging lines, even if the diesel generator, energy storage battery, and photovoltaic power generation system are intact, the entire ship will lose its power source due to the loss of power supply channels. If the energy storage battery is set to be mobile, in the event of a line failure, the diesel generator and photovoltaic power generation system can be used to charge the battery. Based on this, the energy storage battery can be manually transported to the load side (such as the electric motor that drives the ship), enabling secondary operation of the ship, allowing it to sail to shore for emergency repairs. Summary of the Invention

[0004] An embodiment of the present invention provides a ship power grid scheduling method taking into account mobile energy storage failures, which can communicate ship sources and loads and achieve efficient coordination of units under the condition of considering damage to the ship power supply line.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a ship power grid scheduling method, based on a ship power grid including a diesel generator, an energy storage battery and a photovoltaic power generation system, comprising the following steps:

[0006] Step 1: Get the sunshine intensity and load forecast data: Contact the base to obtain the sunshine intensity forecast data for the next 24 hours. At the same time, based on the ship's operation needs, predict the ship's load power consumption for the next 24 hours, expressed as a set Where T = 24 represents the day-ahead scheduling period, G t Indicates the sunshine intensity at time t, t = 1, 2, ..., T, P t L Indicates the load power consumption at time t;

[0007] Step 2: Quantitatively analyze the power generation characteristics of photovoltaic panels and diesel generators, and establish the operating constraint formula of diesel generators and photovoltaic power generation systems:

[0008] First, the power P of the photovoltaic power generation system at time t is calculated according to the photovoltaic power generation formula.t PV =P STC G t [1+ε(T c,t -T r )] / G STC , where P STC G is the maximum test power output by the photovoltaic power generation system under standard test conditions. STC is the sunshine intensity under standard test conditions, ε is the power temperature coefficient, T c,t is the operating temperature of the solar panel at time t, T r is the reference temperature;

[0009] Then build the diesel generator operation model: Where P t G is the operating power of the diesel generator at time t, Indicates the start and stop status of the diesel generator at time t, Indicates the rated operating power of the diesel generator; the operating power of the diesel generator must be less than the rated power generation power, and its operating power must be less than the rated climbing rate when adjusted;

[0010] Step 3: Quantitatively analyze the spatiotemporal transfer and charging / discharging characteristics of mobile energy storage and establish an economic dispatch model for faulty ship power grids:

[0011] Step 31: Establish the spatial transfer constraints of the energy storage battery, expressed as:

[0012]

[0013]

[0014]

[0015] Mode Indicates that the energy storage battery k has one and only one position at time t, k = 1, 2;

[0016] Mode Indicates that the energy storage battery k moves from station i to road ij, i≠j, or stays at station i, i=j;

[0017] Mode Indicates that energy storage battery k enters site j from road ij;

[0018] in Indicates the spatiotemporal position symbol of the energy storage battery k: Represents the energy storage battery k on the way from position i to position j, Indicates that the energy storage battery k is not on the corresponding road, represents the spatial location; T is the scheduling cycle time;

[0019] Step 32: Establish energy constraints for the energy storage battery, expressed as:

[0020]

[0021]

[0022]

[0023] Mode Indicates that the charging power of energy storage battery k must be less than the rated power constraint;

[0024] Mode Indicates that the discharge power of the energy storage battery k must be less than the rated power constraint;

[0025] Mode Represents the relationship between the energy of the energy storage battery k and the charge and discharge power;

[0026] in, and They represent the charging power and discharging power of energy storage battery k at site i at time t, and They represent the charging and discharging signs of the energy storage battery k at site i at time t, and They represent the rated charging power and discharging power of the energy storage battery k, η represents the charging and discharging efficiency of the energy storage battery k, represents the energy storage and rated energy storage of energy storage battery k at time t;

[0027] Step 33: Considering that the fuel oil carried by ships cannot be replenished in the ocean, the grid operation is optimized with the goal of minimizing the daily fuel consumption of the system:

[0028]

[0029]

[0030] In the formula represents the fuel consumption at time t, m4, m3, m2, m1 and m0 are the fuel consumption characteristic parameters of the diesel generator;

[0031] Step 4: The linearized scheduling model is a mixed integer linearization problem, and Gurobi linear programming is used to solve it. With the goal of minimizing the daily fuel consumption of diesel generators, a day-ahead scheduling model for the faulty ship power grid is constructed:

[0032] The formula Linearization is used to efficiently solve the scheduling model. The formula is solved using the commercial solver CPLEX using the yalmip software on the MATALB platform.

[0033] Step 5: Based on the obtained grid dispatch strategy, output the optimization results to guide the operation decisions of diesel generators and energy storage batteries.

[0034] Furthermore, the diesel generator operation model in step 2 also includes Take 1000kW, Represents the rated ramp rate of the diesel generator; the spatial transfer constraint formula established in step 31 also includes Indicates that the energy storage battery returns to the origin when the scheduling ends.

[0035] Furthermore, the energy constraint formula established in step 32 also includes:

[0036] Indicates that the energy storage battery k cannot be charged and discharged at the same time;

[0037] Indicates that the energy of the energy storage battery k is less than the rated capacity constraint:

[0038] Indicates that the energy storage will return to the initial value when the scheduling ends;

[0039] and They represent the rated charging power and discharging power of the energy storage battery k, Represents the energy storage of energy storage battery k at time t.

[0040] Furthermore, in step 33, the energy storage battery exchanges power with the diesel generator, photovoltaic power generation system and load according to the following constraint formula:

[0041]

[0042]

[0043]

[0044] The beneficial effects of the present invention are as follows: the patented ship power grid dispatching method fully considers the ship power supply line failure scenario, and by utilizing mobile energy storage to communicate power sources and loads, it not only realizes power transmission but also reduces fuel consumption for ship operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a spatial position relationship diagram of the diesel generator, photovoltaic power generation system and load of the present invention;

[0046] Figure 2 This is a graph showing photovoltaic power generation and load power consumption in an embodiment of the present invention;

[0047] Figure 3 A diagram showing the location of a mobile energy storage space in an embodiment of the present invention;

[0048] Figure 4 This is a power diagram of mobile energy storage charging and discharging in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0050] Example 1

[0051] The present invention relates to the technical field of new energy storage scheduling. An embodiment provides a method for scheduling a faulty ship power grid taking into account movable energy storage. The method can communicate the ship's source and load under the condition that the ship's power supply line is damaged, thereby achieving efficient coordination of the units.

[0052] Reference Figure 1 As shown, the ship power grid of the present invention includes a diesel generator, an energy storage battery and a photovoltaic power generation system. To achieve the above-mentioned purpose, the embodiment of the present application adopts the following steps:

[0053] Step 1: Contact the base to obtain the sunshine intensity forecast data for the next 24 hours. At the same time, based on the ship's operation needs, predict the power load for the next 24 hours, which is represented by set A:

[0054]

[0055] Where, T represents the day-ahead scheduling period (taken as 24 hours), G t represents the sunshine intensity at time t (t=1,2,…,T), P t L Indicates the load power consumption at time t.

[0056] Step 2: Quantitatively analyze the power generation characteristics of photovoltaic panels and diesel generators, and establish the operating constraints of the diesel generator and photovoltaic power generation system. First, according to the photovoltaic power generation formula, the photovoltaic power generation power is calculated as:

[0057] P t PV =P STC G t [1+ε(T c,t -T r )] / G STC (2)

[0058] Where, P t PV is the photovoltaic power generation power at time t; P STC G is the maximum test power of photovoltaic output under standard test conditions; STC is the sunlight intensity under standard test conditions; ε is the power temperature coefficient; T c,t is the operating temperature of the solar panel at time t; T r is the reference temperature.

[0059] Then, a diesel generator operation model is constructed. The operating power of the diesel generator must be less than the rated power generation power, and its operating power adjustment must be less than the rated ramp rate:

[0060]

[0061] Where, P t G is the operating power of the diesel generator at time t, Indicates the start and stop status of the diesel generator at time t, Indicates the rated operating power of the diesel generator.

[0062] Step 3: Quantitatively analyze the operational characteristics of mobile energy storage and establish a mobile energy storage operational model. The spatial transfer constraints of mobile energy storage can be expressed in equations (4) to (6). Equation (4) indicates that mobile energy storage k (k = 1, 2) has one and only one location at time t, equation (5) indicates that it transfers from site i to road ij (i ≠ j) or stays at site i (i = j), and equation (6) indicates that it enters site j from road ij.

[0063]

[0064]

[0065]

[0066] Where, The spatiotemporal position flag of the mobile energy storage k, where a value equal to 1 indicates that the mobile energy storage k is on the road from position i to position j, and a value equal to 0 indicates that the mobile energy storage k is not on the corresponding road; Marks the spatial position of vehicle in park i; T is the scheduling cycle time.

[0067] The energy constraints of mobile energy storage k (k = 1, 2) can be expressed as equations (7) to (9). Equations (7) and (8) respectively indicate that the charging power and discharging power of mobile energy storage k must be less than the rated power constraint, and equation (9) represents the relationship between the energy and charging and discharging power of mobile energy storage k:

[0068]

[0069]

[0070]

[0071] Where, and They represent the charging power and discharging power of mobile energy storage k at site i at time t, and They represent the charging and discharging signs of mobile energy storage k at site i at time t, and They represent the rated charging power and discharging power of the mobile energy storage k, η represents the charging and discharging efficiency of the mobile energy storage, Represents the energy storage of mobile energy storage k at time t.

[0072] Step 4: Considering that the fuel oil carried by ships cannot be replenished in the ocean, the grid operation is optimized with the goal of minimizing the daily fuel consumption of the system, as shown in Equations (10) and (11):

[0073]

[0074]

[0075] Where, represents the fuel consumption at time t, m4, m3, m2, m1 and m0 are the fuel consumption characteristic parameters of the diesel generator.

[0076] Step 5: Linearize Equation (11) to efficiently solve the scheduling model. Based on this, the problem is solved by calling the commercial solver CPLEX using the yalmip software on the MATALB platform.

[0077] Step 6: Output the operation decision of diesel generator and mobile energy storage according to the optimization results.

[0078] Example 2

[0079] An embodiment of the present invention provides a power grid scheduling method that further considers the multi-dimensional impact of meteorological factors, comprising the following steps:

[0080] Step 1: Contact the base to obtain the sunshine intensity forecast data for the next 24 hours. At the same time, based on the ship's operation needs, predict the power load for the next 24 hours, represented by set A:

[0081]

[0082] Where, T represents the day-ahead scheduling period (taken as 24 hours), G trepresents the sunshine intensity at time t (t=1,2,…,T), P t L Indicates the load power consumption at time t, such as Figure 2 shown.

[0083] Step 2: Quantitatively analyze the power generation characteristics of photovoltaic panels and diesel generators and establish generator operation constraints. First, according to the photovoltaic power generation formula, the photovoltaic power generation power is calculated as:

[0084] P t PV =P STC G t [1+ε(T c,t -T r )] / G STC (2)

[0085] Where, P t PV is the photovoltaic power generation at time t, such as Figure 2 As shown; P STC G is the maximum test power of photovoltaic output under standard test conditions; STC is the sunlight intensity under standard test conditions; ε is the power temperature coefficient; T c,t is the operating temperature of the solar panel at time t; T r is the reference temperature.

[0086] Then, a diesel generator operation model is constructed. The operating power of the diesel generator must be less than the rated power generation power, and its operating power adjustment must be less than the rated ramp rate:

[0087]

[0088]

[0089] Where, P t G is the operating power of the diesel generator at time t, Indicates the start and stop status of the diesel generator at time t, Indicates the rated operating power of the diesel generator (taken as 1000kW), Indicates the rated climbing rate of the diesel generator.

[0090] Step 3: Quantitatively analyze the operational characteristics of mobile energy storage and establish a mobile energy storage operational model. The spatial transfer constraints of mobile energy storage can be expressed in equations (5) to (8). Equation (5) indicates that mobile energy storage k (k = 1, 2) has one and only one location at time t; Equation (6) indicates that it transfers from site i to road ij (i ≠ j) or stays at site i (i = j); Equation (7) indicates that it enters site j from road ij; and Equation (8) indicates that the mobile energy storage returns to the origin at the end of the dispatch.

[0091]

[0092]

[0093]

[0094]

[0095] In the formula Indicates the spatiotemporal location flag of mobile energy storage k. Its value equal to 1 indicates that mobile energy storage k is on the road from position i to position j, while equal to 0 indicates that mobile energy storage k is not on the corresponding road. Marks the spatial position of vehicle in park i; T is the scheduling cycle time.

[0096] The energy constraints of mobile energy storage k (k = 1, 2) can be expressed as equations (9) to (13). Among them, equations (9) and (10) indicate that the charging power and discharging power of mobile energy storage k must be less than the rated power constraint, equation (11) indicates that mobile energy storage k cannot be charged and discharged at the same time, equation (12) indicates the relationship between the energy and charging and discharging power of mobile energy storage k, equation (13) indicates that the energy of mobile energy storage k must be less than the rated capacity constraint, and equation (14) indicates that the energy storage must return to the initial value at the end of the dispatch:

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103] Where, and They represent the charging power and discharging power of mobile energy storage k at site i at time t, and They represent the charging and discharging signs of mobile energy storage k at site i at time t, and They represent the rated charging power and rated discharging power of the mobile energy storage k, both of which are taken as 1000kW, and h represents the charging and discharging efficiency of the mobile energy storage. It represents the energy storage of mobile energy storage k at time t, and the rated energy storage is 2000kW.

[0104] In addition, the mobile energy storage system needs to exchange power with the diesel generator, photovoltaic power generation system, and load. The corresponding constraints can be expressed as:

[0105]

[0106]

[0107]

[0108] Step 4: Considering that the fuel oil carried by ships cannot be replenished in the ocean, the grid operation is optimized with the goal of minimizing the daily fuel consumption of the system, as shown in Equations (18) and (19):

[0109]

[0110]

[0111] Where, represents the fuel consumption at time t, m4, m3, m2, m1 and m0 are the fuel consumption characteristic parameters of the diesel generator.

[0112] Step 5: Linearize Equation (19) to efficiently solve the scheduling model.

[0113] First, define the function g(P t G ) satisfies the following formula:

[0114] g(P t G )=m4(P t G ) 4 +m3(P t G ) 3 +m2(P t G ) 2 +m1(P t G )+m0 (20)

[0115] On this basis, according to the operating power range of the diesel generator Set N+1 breakpoint powers at equal intervals, which satisfy the following relationship:

[0116]

[0117] For any power P t G , can be expressed by combining the breakpoint powers under different weights:

[0118]

[0119] Finally, the fuel consumption of the diesel generator at time t can be expressed as:

[0120]

[0121] Where, Indicates the power weight corresponding to breakpoint n.

[0122] Through the above processing, the faulty ship power grid scheduling model is transformed into a classic mixed-integer linear programming problem. Based on the MATALB platform, the commercial solver CPLEX is called using the yalmip software to solve the problem.

[0123] Step 6: Output the operation decision of diesel generator and mobile energy storage based on the optimization results.

[0124] Finally, the daily diesel consumption is 6871 liters. Figure 3 and Figure 4 It can be seen that mobile energy storage can meet the power demand of faulty ships and reduce onboard fuel consumption by flexibly adjusting spatial position and charging and discharging.

[0125] The embodiments of the present invention provide a method for dispatching a faulty ship power grid that takes mobile energy storage into account. This method fully considers the scenario in which the ship's power supply line is damaged. By flexibly dispatching mobile energy storage to charge at the power source and discharge at the load, it not only meets the ship's energy needs but also significantly reduces onboard fuel consumption.

[0126] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A ship power grid dispatching method based on a ship power grid comprising a diesel generator, an energy storage battery, and a photovoltaic power generation system, characterized in that: The following steps are included Step 1: Contact the base to obtain the sunshine intensity forecast data for the next 24 hours, and also predict the ship load power consumption for the next 24 hours, expressed as a set Where T = 24 represents the day-ahead scheduling period, G t Indicates the sunshine intensity at time t, t = 1, 2, ..., T, P t L Indicates the load power consumption at time t; Step 2: Establish the operating constraint formula of diesel generator and photovoltaic power generation system First calculate the power P of the photovoltaic power generation system at time t t PV =P STC G t [1+ε(T c,t -T r )] / G STC , where P STC G is the maximum test power output by the photovoltaic power generation system under standard test conditions. STC is the sunshine intensity under standard test conditions, ε is the power temperature coefficient, T c,t is the operating temperature of the solar panel at time t, T r is the reference temperature; Then build the diesel generator operation model: Where P t G is the operating power of the diesel generator at time t, Indicates the start and stop status of the diesel generator at time t, Indicates the rated operating power of the diesel generator; the operating power of the diesel generator is less than the rated generating power, and at the same time, its operating power is less than the rated climbing rate when adjusted; Step 3: Quantitatively analyze the spatiotemporal transfer and charge-discharge characteristics of mobile energy storage and establish a mobile energy storage operation model: Step 31: Establish the spatial transfer constraint formula of the energy storage battery: Mode Indicates that the energy storage battery k has one and only one position at time t, k = 1, 2; Mode Indicates that the energy storage battery k moves from station i to road ij, i≠j, or stays at station i, i=j; Mode Indicates that energy storage battery k enters site j from road ij; in Indicates the spatiotemporal position symbol of the energy storage battery k: Represents the energy storage battery k on the way from position i to position j, Indicates that the energy storage battery k is not on the corresponding road, represents the spatial location; T is the scheduling cycle time; Step 32: Establish the energy constraint formula of the energy storage battery: Mode Indicates that the charging power of energy storage battery k is less than the rated power constraint; Mode Indicates that the discharge power of energy storage battery k is less than the rated power constraint; Mode Represents the relationship between the energy of the energy storage battery k and the charge and discharge power; in, and They represent the charging power and discharging power of energy storage battery k at site i at time t, and They represent the charging and discharging signs of the energy storage battery k at site i at time t, and They represent the rated charging power and discharging power of the energy storage battery k, η represents the charging and discharging efficiency of the energy storage battery k, represents the energy storage of energy storage battery k at time t; Step 33: Optimize grid operation with the goal of minimizing daily fuel consumption: In the formula represents the fuel consumption at time t, m4, m3, m2, m1 and m0 are the fuel consumption characteristic parameters of the diesel generator; Step 4: Use Gurobi linear programming to solve the problem and build a day-ahead dispatch model for the faulty ship power grid with the goal of minimizing the daily fuel consumption of diesel generators: The formula st Linearization, based on the MATALB platform, uses yalmip software to call the commercial solver CPLEX to solve the formula; Step 5: Instruct the operation of diesel generators and energy storage batteries according to the obtained grid dispatching strategy.

2. A ship power grid dispatching method according to claim 1, characterized in that: The diesel generator operation model in step 2 also includes Take 1000kW, Represents the rated ramp rate of the diesel generator; the spatial transfer constraint formula established in step 31 also includes Indicates that the energy storage battery returns to the origin when the scheduling ends.

3. A ship power grid dispatching method according to claim 2, characterized in that: The energy constraint formula established in step 32 also includes: Indicates that the energy storage battery k cannot be charged and discharged at the same time; Indicates that the energy of the energy storage battery k is less than the rated capacity constraint: Indicates that the energy storage will return to the initial value when the scheduling ends; and They represent the rated charging power and discharging power of the energy storage battery k, and Represents the energy storage and rated energy storage of energy storage battery k at time t.

4. A ship power grid dispatching method according to claim 3, characterized in that: In step 33, the energy storage battery exchanges power with the diesel generator, photovoltaic power generation system and load according to the following constraint formula:

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