Double-layer optimization method for operation of fishing, light storage and storage complementary system

Abstract

The invention relates to a fishing-light-storage complementary system operation double-layer optimization method, which comprises the steps of collecting parameter data of photovoltaic equipment and energy storage equipment, selecting bait casting equipment, an aerator and irrigation and drainage equipment as loads, and constructing a fishing-light-storage complementary system model; constructing a fishing light storage complementary system net load upper-layer objective function considering the light abandoning rate, and carrying out optimization solving to obtain the net load and the energy storage charging and discharging power of the system in each time period; performing grid-connected risk safety judgment on the photovoltaic system, and if the grid-connected risk safety is not met, increasing the light abandoning rate to perform optimization solution again; and if yes, constructing a fishery, photovoltaic and energy storage complementary system low-carbon economic operation lower-layer objective function which considers the lowest carbon emission and comprehensive operation cost, and performing optimization solution to obtain the output power of each photovoltaic device and energy storage device. Compared with the prior art, the photovoltaic absorption rate, the system operation economy and the energy utilization efficiency can be effectively improved and the carbon emission can be reduced on the premise of meeting constraints such as system load requirements and safe operation.

Description

Technical Field

[0001] The present invention relates to the field of fishery-solar-energy-storage complementary systems, and in particular to a double-layer optimization method for the operation of fishery-solar-energy-storage complementary systems. Background Art

[0002] The "fish-solar-energy-storage" complementary integrated energy system is one of the typical representatives of the new smart fishery. However, there is currently little research and analysis on the optimal configuration, safe and coordinated operation of the "fish-solar-energy-storage" complementary system specifically targeting photovoltaics, energy storage and typical aquaculture loads in fish farms.

[0003] At present, most of the research on fishery-related integrated energy systems focuses on the parameter optimization of individual typical equipment, and only considers one of the links such as capacity configuration or optimization control. There is little analysis of the typical load characteristics of fishery farming, and insufficient consideration of the safety risks of photovoltaic grid connection of "fishery photovoltaic storage". With the advancement of the construction of "fishery photovoltaic storage" all-electric fishery, in order to take into account the photovoltaic consumption, energy storage output and load demand of the fishery, it is necessary to conduct in-depth research on the low-carbon operation optimization method of the "fishery photovoltaic storage" complementary system. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a double-layer optimization method for the operation of a fishery-photovoltaic-storage complementary system, so as to improve the photovoltaic absorption rate, system operation economy and energy utilization efficiency, and reduce carbon emissions.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A two-layer optimization method for operation of a fishery-solar-storage complementary system comprises the following steps:

[0007] Collect parameter data of photovoltaic equipment and energy storage equipment, select feeding equipment, aerators and irrigation and drainage equipment as loads, build a power consumption model for aquaculture equipment loads, and thus build a fishery-photovoltaic-storage complementary system model;

[0008] The upper objective function of the net load of the fishery-photovoltaic-storage complementary system considering the abandoned light rate is constructed, and the corresponding constraints are set, including the abandoned light rate constraint, the energy storage device charging and discharging and the charge number constraint. The fishery-photovoltaic complementary system model is optimized and solved to obtain the system net load and energy storage charging and discharging power in each time period.

[0009] Considering the voltage deviation, voltage fluctuation and harmonic level of the photovoltaic grid-connected point of the fishery-photovoltaic-storage complementary system, the risk safety of the photovoltaic system grid-connected is judged. If the judgment conditions are not met, the abandonment rate in the calculation process of the upper objective function is increased, and the optimal solution is sought again; if the judgment conditions are met, the lower objective function of the low-carbon economic operation of the fishery-photovoltaic-storage complementary system considering carbon emissions and the lowest comprehensive operating cost is constructed according to the optimal abandonment rate, system net load and energy storage charging and discharging power. The corresponding constraints are set, including system power balance constraints and transmission line capacity constraints, and the fishery-photovoltaic complementary system model is optimally solved to obtain the output power of each photovoltaic device and energy storage device as the system collaborative operation optimization plan.

[0010] Furthermore, the expression of the upper objective function of the net load of the fishery-solar-storage complementary system considering the abandoned light rate is:

[0011]

[0012] P D，1 =W D (1) / Δt

[0013] Where F1 is the upper objective function of the net load of the fishery-solar-storage complementary system considering the abandoned light rate, P D,t is the net load of the system during period t, is the average daily load of the system, P D，1 is the initial load of the system within a day, W D (1) is the total initial power consumption of the system within a day, Δt is the time interval between each period, ω pv,t is the system's abandoned light rate during period t, 0≤ω pv,t ≤1, P pv,t is the photovoltaic power generation power of the system during period t, P d,t is the discharge power of the energy storage system during period t, P c,t is the charging power of the energy storage system during period t, η d is the discharge efficiency of the system energy storage device, η c is the charging efficiency of the system energy storage device, and T is the total daily cycle.

[0014] Furthermore, the expression of the light abandonment rate constraint is:

[0015] 0≤ω pv,t ≤1

[0016] The expression of the charge and discharge and charge number constraint of the energy storage device is:

[0017]

[0018] Where P c,max is the maximum charging power of the energy storage system, P d,max is the maximum discharge power of the energy storage system, uc,t is the charging state of the energy storage system during period t, u d,t is the discharge state of the energy storage system during period t, Q soc,t is the charge of the energy storage device during period t, Q soc,min Q is the minimum charge allowed by the energy storage device. soc,max The maximum charge allowed for the energy storage device.

[0019] Furthermore, the photovoltaic system grid-connected risk safety judgment includes: voltage deviation risk judgment caused by distributed photovoltaic grid-connected, voltage fluctuation risk judgment at the common coupling point of distributed photovoltaic grid-connected, and harmonic risk judgment of distributed photovoltaic grid-connected;

[0020] The expression for judging the voltage deviation risk caused by the distributed photovoltaic grid connection is:

[0021] U PV,t ≤U PVref,max

[0022]

[0023] Where U PV,t is the photovoltaic voltage at the grid-connected point during period t, U PVref,max is the upper limit of the reference voltage allowed by the grid connection point, U0 is the bus voltage, R is the resistance of the grid connection point to the bus line, X is the reactance of the grid connection point to the bus line, P t is the active power of the grid-connected point load during period t, Q t is the reactive power of the grid-connected point load during period t, Q PV,t is the photovoltaic grid-connected reactive power in period t;

[0024] The expression for determining the voltage fluctuation risk of the distributed photovoltaic grid-connected common coupling point is:

[0025] ΔU PCC,t ≤U PVref,PCC

[0026]

[0027] ΔS=P PV +jQ PV

[0028] In the formula, ΔU PCC,t is the voltage fluctuation of the photovoltaic grid-connected common coupling point during period t, U PVref,PCC is the allowable value of the grid-connected point reference voltage, S N is the rated apparent power of the line, U N is the line rated voltage, ΔS is the apparent power change after photovoltaic access, is the impedance angle of the system equivalent impedance, θ is the photovoltaic power source power factor angle, and j is the imaginary unit;

[0029] The expression for determining the harmonic risk of distributed photovoltaic grid-connected power generation is:

[0030]

[0031] In the formula, is the harmonic current generated by the photovoltaic system at the grid-connected point during period t, is the harmonic current reference value, is the photovoltaic current at the grid-connected point, Z eq,load is the equivalent wave impedance of the grid-connected load, Z eq,grid is the equivalent wave impedance on the grid side, is the harmonic voltage generated by the photovoltaic system at the grid-connected point during period t, is the harmonic voltage reference value, is the harmonic current generated by the photovoltaic system at the grid-connected point during period t, Z k is the line impedance of the adjacent load node when the filter element is not considered, Z L is the adjacent load impedance when filtering elements are not taken into account, and n is the total number of nodes in the distribution network.

[0032] Furthermore, if any one of the voltage deviation risk judgment caused by distributed photovoltaic grid connection, the voltage fluctuation risk judgment at the common coupling point of distributed photovoltaic grid connection, and the harmonic risk judgment of distributed photovoltaic grid connection is not met, it is considered that the judgment condition is not met.

[0033] Furthermore, the expression for increasing the abandoned light rate in the process of calculating the upper layer objective function is:

[0034] ω pv,t =ω pv,t +Δω pv

[0035] In the formula, Δω pv It is a micro increment of the unit light abandonment rate.

[0036] Furthermore, in the fishery-solar-storage complementary system model, the calculation expression of the total power consumption of the system is:

[0037] W D (t) = W fee (t)+W oxy (t)+W pum (t)+W other (t)

[0038] Where W D (t) is the total power consumption of the fishery-solar-storage complementary system, W fee (t) is the power consumption of the bait feeding equipment, W oxy (t) is the power consumption of the oxygenation equipment, W pum (t) is the power consumption of irrigation and drainage equipment, W other(t) is the electricity consumption other than that of the breeding equipment;

[0039]

[0040] Where P fee is the power of the bait throwing equipment, k f is the number of bait placements, S f is the bait placement distance, V f is the bait delivery speed, P oxy is the power of the oxygen enrichment equipment, t o is the working time of the oxygen enrichment equipment, P pum is the power of irrigation and drainage equipment, k p is the frequency of fish farm water replacement, n ac is the scale of fish farm, h p is the water change height, y p is the aerator water pump flow.

[0041] Furthermore, the expression of the lower objective function of the low-carbon economic operation of the fishery-solar-storage complementary system considering the lowest carbon emissions and comprehensive operating costs is:

[0042] minF2=C1+C2+C3+C4-C5

[0043] Where F2 is the lower objective function of the low-carbon economic operation of the fishery-solar-energy-storage complementary system considering the lowest carbon emissions and comprehensive operating costs; C1 is the operating cost of the photovoltaic system; C2 is the operating and maintenance cost of the energy storage device; C3 is the carbon trading cost of the system; C4 is the power purchase cost of the grid; and C5 is the income from photovoltaic grid connection.

[0044] Furthermore, the calculation expression of the photovoltaic system operation cost is:

[0045]

[0046] In the formula, ρ pv is the photovoltaic system operation and maintenance cost coefficient, P pv,t is the photovoltaic power generation power of the system in period t, and T is the total daily cycle;

[0047] The calculation expression of the operation and maintenance cost of the energy storage device of the system is:

[0048]

[0049] In the formula, ρ soc is the operation and maintenance cost coefficient of the energy storage device, P soc,t is the charging power of the energy storage system during period t, P d,t is the discharge power of the energy storage system during period t, P c,t The charging power of the energy storage system during period t;

[0050] The calculation expression of the system carbon trading cost is:

[0051]

[0052] Where d is the carbon capture cost coefficient, P buy,t is the amount of electricity purchased from the power grid during period t, Δt is the time interval between periods, C i is the coal consumption coefficient per unit of electricity;

[0053] The calculation expression of the power purchase cost of the system grid is:

[0054]

[0055] In the formula, p grid,t is the electricity selling price of the distribution network during period t;

[0056] The calculation expression of the photovoltaic grid-connected income is:

[0057]

[0058] In the formula, p pvout,t is the photovoltaic grid-connected purchase price during period t, P pvout,t is the photovoltaic grid-connected power of the system during period t.

[0059] Furthermore, the expression of the system power balance constraint is:

[0060] P buy,t +P pv,t +P d,t =P D,t +P c,t +P pvout,t

[0061] Where P buy,t P is the amount of electricity purchased from the power grid during period t. pvout,t is the photovoltaic grid-connected power of the system during period t, P d,t is the discharge power of the energy storage system during period t, P c,t is the charging power of the energy storage system during period t, P D,t is the net load of the system during period t, P pv,t is the photovoltaic power of the system during period t;

[0062] The expression of the transmission line capacity constraint is:

[0063] 0<P buy,t <P Lmax

[0064] Where P Lmax is the maximum transmission power of the transmission line.

[0065] Compared with the prior art, the present invention has the following advantages:

[0066] The double-layer optimization method for the operation of the fishery-photovoltaic-storage complementary system proposed in the present invention first solves the system net load objective function considering the optimal absorption rate according to the system net load and the system daily average load, and introduces a discriminant formula considering the grid-connected safety risk of the photovoltaic system to adjust the abandoned light rate and realize the optimal absorption of photovoltaic power in the "fishery-photovoltaic-storage" system on the basis of ensuring the safe and stable operation of the system;

[0067] Then, based on the optimal abandonment rate, the obtained system net load and the energy storage charging and discharging power, the lower objective function of the low-carbon economic operation of the fishery-photovoltaic-storage complementary system is solved according to the lowest carbon emissions and comprehensive operating costs, and the output power of each photovoltaic device and energy storage device is obtained, which improves the operating economy of the entire system and reduces the carbon emission level;

[0068] On the whole, the present invention can effectively coordinate the photovoltaic output fluctuations of the "fish-solar-storage" system with the charging and discharging power of the energy storage device. On the premise of meeting the system load requirements and safe operation constraints, it can effectively improve the photovoltaic absorption rate, system operation economy and energy utilization efficiency, and reduce carbon emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 A schematic flow chart of a dual-layer optimization method for operation of a fishery-solar-storage complementary system provided in an embodiment of the present invention;

[0070] Figure 2 A schematic diagram of a typical distributed photovoltaic grid-connected structure provided in an embodiment of the present invention;

[0071] Figure 3 A schematic diagram of an equivalent circuit for analyzing photovoltaic grid-connected voltage fluctuations provided in an embodiment of the present invention;

[0072] Figure 4 The figure is a schematic diagram of an equivalent circuit of a photovoltaic grid-connected harmonic source provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0073] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0074] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0076] Example 1

[0077] like Figure 1 As shown, this embodiment provides a two-layer optimization method for the operation of a fishery-solar-storage complementary system, including the following steps:

[0078] S1: Collect parameter data of energy equipment and energy-consuming equipment such as photovoltaic equipment and energy storage equipment in the fishery-photovoltaic-storage complementary system, data such as line parameters of the photovoltaic system grid connection point, and basic data of fishery loads during typical periods. Consider the typical fishery aquaculture operation mode, and select three important typical loads such as feeding equipment, aerators, and irrigation and drainage (filtration and replacement) equipment as loads to construct a load power consumption model of typical aquaculture equipment in the "fishery-photovoltaic-storage" system, thereby constructing a fishery-photovoltaic-storage complementary system model;

[0079] The load power consumption model of typical aquaculture equipment in the “fish-solar-energy-storage” system is as follows:

[0080]

[0081] Where: W fee , W oxy , W pum The power consumption of bait feeding, aeration and irrigation and drainage equipment is in kW·h; P fee , P oxy , P pum is the power of feeding, aeration and irrigation and drainage equipment, in kW; S f V is the bait placement distance, in m; f is the bait delivery speed, in m / s; k f is the number of bait placements; t o is the working time of the aeration equipment, in h; yp is the flow rate of the aerator pump, in m 3 / h;n ac is the scale of fish farm, m 2 ;k p The frequency of changing the fish farm water; h p is the water exchange height, m.

[0082] The comprehensive load of the “fish-solar-energy-storage” system is defined as:

[0083] W D (t) = W fee (t)+W oxy (t)+W pum (t)+W other (t)

[0084] Where W D is the total power consumption of the “fishery-solar-energy-storage” system, W other It refers to the electricity consumption other than that of breeding equipment, including but not limited to system lighting, domestic electricity, central air-conditioning, factory electricity, etc.

[0085] S2: Considering the photovoltaic output characteristics of the "fishery-solar-storage" system, the constraints of abandoned photovoltaic power, the charging and discharging constraints of the energy storage device, and the capacity constraints, the relevant constraints of the upper objective function are constructed:

[0086] 1) Constraints on abandoned light rate

[0087] 0≤ω pv,t ≤1

[0088] In the formula, ω pv,t is the system light abandonment rate.

[0089] 2) Energy storage device charging and discharging and charge number constraints

[0090]

[0091] Where P c,max is the maximum charging power of the energy storage system, P d,max is the maximum discharge power of the energy storage system; d and tu represent the energy storage charging and discharging states respectively, both of which are 0 and 1 variables, indicating that the energy storage device can only work in one of the three states: charging, discharging and standby.

[0092]

[0093] In the formula, Q soc,min Q is the minimum charge allowed by the energy storage device. soc,min It is the maximum charge number allowed by the energy storage device; at the same time, the energy storage device works continuously to ensure that the energy storage charge number is equal at the beginning and end of the cycle.

[0094] S3: Based on the proposed constraints, the upper objective function of the net load of the fishery-solar-storage complementary system considering the abandoned light rate is constructed, and the optimal solution is performed to obtain the system net load and energy storage charging and discharging power in each period;

[0095] The upper objective function is specifically:

[0096]

[0097] P D，1=W D (1) / Δt

[0098] Where P D,t is the net load of the system during period t, P D,t When >0, it means that the system cannot meet the demand with its internal energy equipment and needs to purchase electricity from the grid. D,t = 0, indicating that the system's internal supply and demand are balanced, P D,t When P < 0, it indicates that the output of the energy equipment in the system is greater than the load demand, the energy storage device cannot absorb the excess photovoltaic power generation, and the excess photovoltaic output is connected to the grid; av D is the average daily load of the system, P D,1 is the initial load of the system within a day; ω pv,t is the system abandonment rate, 0≤ω pv,t ≤1, when calculating for the first time, take ω pv,t =0, that is, at this time, all the excess photovoltaic power generation is connected to the grid; η c , η d are the charging and discharging efficiencies of the energy storage device of the system, where 0<η c <1, 0<η d <1; T is the total daily cycle, T is 24.

[0099] S4: Considering the voltage deviation, voltage fluctuation and harmonic level of the photovoltaic grid-connected point of the fishery-photovoltaic-storage complementary system, the grid-connected risk safety judgment of the photovoltaic system is carried out; specifically:

[0100] 1) Identification of voltage deviation risk caused by distributed photovoltaic grid connection

[0101] U PV,t ≤U PVref,max

[0102]

[0103] Where U PV,t is the photovoltaic voltage at the grid-connected point during period t; U PVref,max is the upper limit of the reference voltage allowed at the grid connection point; R and X are the resistance and reactance of the line from the grid connection point to the busbar respectively; P t , Q t is the grid-connected point load; U0 is the bus voltage. Distributed photovoltaic grid connection changes the power distribution of the distribution network, causing voltage fluctuations at each load node in the system, which may cause node voltage to exceed the limit. The typical structure of distributed photovoltaic grid connection is as follows: Figure 2 As shown;

[0104] 2) Identification of voltage fluctuation risk at the common coupling point of distributed photovoltaic grid

[0105] ΔU PCC,t ≤U PVref,PCC

[0106]

[0107] ΔS=P PV +jQ PV

[0108] In the formula, ΔU PCC is the voltage fluctuation at the point of common coupling (PCC) of the photovoltaic grid, U PVref,PCC is the allowable value of the grid-connected point reference voltage; S N is the rated apparent power of the line; ΔS is the apparent power change after photovoltaic access. The equivalent circuit for photovoltaic grid-connected voltage fluctuation analysis is as follows: Figure 3 As shown;

[0109] 3) Distributed photovoltaic grid-connected harmonic risk assessment

[0110]

[0111] In the formula, It is the harmonic current generated by the photovoltaic system at the grid connection point. is the harmonic current reference value; It is the harmonic voltage generated by the photovoltaic system at the grid connection point. is the harmonic voltage reference value; Z eq,load is the equivalent wave impedance of the grid-connected load, Z eq,grid is the equivalent wave impedance of the power grid side; Z k is the line impedance of the adjacent load node when the filter element is not considered, Z L When the adjacent load impedance of the filter element is ignored, the equivalent circuit of the photovoltaic grid-connected harmonic source is as follows: Figure 4 shown.

[0112] S5: If the judgment condition of step S4 is not met, the abandoned light rate in the calculation process of the upper objective function in step S3 is increased, and the system net load and energy storage charging and discharging power are solved again; if the judgment condition is met, the power balance constraints and safe operation constraints of the lower model related system are constructed according to the total energy supply and load power balance of the "fishing-solar-energy-storage" system, the upper and lower limits of the output of each energy supply device and the energy storage device;

[0113] Specifically, the expression for increasing the abandoned light rate in step S3 is:

[0114] ω pv,t =ω pv,t +Δω pv

[0115] In the formula, Δω pv It is a micro increment of the unit light abandonment rate.

[0116] The power balance constraints and safe operation constraints of the lower-level model are as follows:

[0117] 1) System power balance constraints

[0118] P buy,t +P pv,t +P d,t =P D,t +P c,t +P pvout,t

[0119] Where P buy,t P is the amount of electricity purchased from the power grid during period t by the system, which is used to make up for the power shortage of the system when the energy equipment in the system is under-powered; pvout,t It is the amount of photovoltaic power connected to the grid in the system; the sum of the amount of power purchased from the power grid by the "fish-solar-energy-storage" system and the discharge of photovoltaic power and energy storage connected to the grid is equal to the real-time load and the charging of the energy storage device.

[0120] 2) Transmission line capacity constraints

[0121] 0<P buy,t <P Lmax

[0122] Where P Lmax is the maximum transmission power of the transmission line.

[0123] S6: According to the desired optimal abandonment rate of solar power, the system net load and the energy storage charging and discharging power, the lower-level objective function of the low-carbon economic operation of the "fishery-solar-energy-storage" system is constructed and optimized based on the carbon emissions and the lowest comprehensive operating cost. The specific output power of each energy supply equipment in the system that meets the optimization goal is obtained, and an optimization plan for the coordinated operation of the system is formed.

[0124] The lower layer objective function is specifically:

[0125] minF2=C1+C2+C3+C4-C5

[0126] In the formula, C1 is the operating cost of the system photovoltaic system; C2 is the operating and maintenance cost of the system energy storage device; C3 is the system carbon trading cost, C4 is the system power grid purchase cost, and C5 is the photovoltaic grid-connected income.

[0127] 1) System photovoltaic system operating costs

[0128]

[0129] In the formula, ρ pv It is the operation and maintenance cost coefficient of the photovoltaic system.

[0130] 2) System energy storage device operating costs

[0131]

[0132] In the formula, ρ soc It is the operation and maintenance cost coefficient of the energy storage device.

[0133] 3) Systematic carbon trading costs

[0134]

[0135] Where d is the carbon capture cost coefficient (yuan / kg), C i is the coal consumption coefficient per unit of electricity (kg / kWh), and the standard coal conversion coefficient is 0.1229kg / kWh.

[0136] 4) Cost of purchasing electricity from the power grid

[0137]

[0138] In the formula, p grid,t is the electricity selling price of the distribution network during period t (yuan / kWh).

[0139] 5) Photovoltaic grid-connected income

[0140]

[0141] In the formula, p pvout,t is the photovoltaic grid-connected purchase price during period t (yuan / kWh).

[0142] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A two-layer optimization method for the operation of a fishery-solar-storage complementary system, characterized in that: The following steps are involved: Collect parameter data of photovoltaic equipment and energy storage equipment, select feeding equipment, aerators and irrigation and drainage equipment as loads, build a power consumption model for aquaculture equipment loads, and thus build a fishery-photovoltaic-storage complementary system model; The upper objective function of the net load of the fishery-photovoltaic-storage complementary system considering the abandoned light rate is constructed, and the corresponding constraints are set, including the abandoned light rate constraint, the energy storage device charging and discharging and the charge number constraint. The fishery-photovoltaic complementary system model is optimized and solved to obtain the system net load and energy storage charging and discharging power in each time period. Considering the voltage deviation, voltage fluctuation and harmonic level of the photovoltaic grid-connected point of the fishery-photovoltaic-storage complementary system, the risk safety of the photovoltaic system grid-connected is judged. If the judgment conditions are not met, the abandonment rate in the calculation process of the upper objective function is increased, and the optimal solution is sought again; if the judgment conditions are met, the lower objective function of the low-carbon economic operation of the fishery-photovoltaic-storage complementary system considering carbon emissions and the lowest comprehensive operating cost is constructed according to the optimal abandonment rate, system net load and energy storage charging and discharging power. The corresponding constraints are set, including system power balance constraints and transmission line capacity constraints, and the fishery-photovoltaic complementary system model is optimally solved to obtain the output power of each photovoltaic device and energy storage device as the system collaborative operation optimization plan.

2. A two-layer optimization method for operation of a fishery-solar-storage complementary system according to claim 1, characterized in that: The expression of the upper objective function of the net load of the fishery-solar-storage complementary system considering the abandoned light rate is: P D，1 =W D (1) / Δt Where F1 is the upper objective function of the net load of the fishery-solar-storage complementary system considering the abandoned light rate, P D,t is the net load of the system during period t, is the average daily load of the system, P D，1 is the initial load of the system within a day, W D (1) is the total initial power consumption of the system within a day, Δt is the time interval between each period, ω pv,t is the system's abandoned light rate during period t, 0≤ω pv,t ≤1, P pv,t is the photovoltaic power generation power of the system during period t, P d,t is the discharge power of the energy storage system during period t, P c,t is the charging power of the energy storage system during period t, η d is the discharge efficiency of the system energy storage device, η c is the charging efficiency of the system energy storage device, and T is the total daily cycle.

3. A two-layer optimization method for operation of a fishery-solar-storage complementary system according to claim 2, characterized in that: The expression of the abandoned light rate constraint is: 0≤ω pv,t ≤1 The expression of the charge and discharge and charge number constraint of the energy storage device is: Where P c,max is the maximum charging power of the energy storage system, P d,max is the maximum discharge power of the energy storage system, u c,t is the charging state of the energy storage system during period t, u d,t is the discharge state of the energy storage system during period t, Q soc,t is the charge of the energy storage device during period t, Q soc,min Q is the minimum charge allowed by the energy storage device. soc,max The maximum charge allowed for the energy storage device.

4. A two-layer optimization method for operation of a fishery-solar-storage complementary system according to claim 2, characterized in that: The photovoltaic system grid-connected risk safety judgment includes: voltage deviation risk judgment caused by distributed photovoltaic grid-connected, voltage fluctuation risk judgment at the common coupling point of distributed photovoltaic grid-connected, and harmonic risk judgment of distributed photovoltaic grid-connected; The expression for judging the voltage deviation risk caused by the distributed photovoltaic grid connection is: IN PV,t ≤U PVref,max Where U PV,t is the photovoltaic voltage at the grid-connected point during period t, U PVref,max is the upper limit of the reference voltage allowed by the grid connection point, U0 is the bus voltage, R is the resistance of the grid connection point to the bus line, X is the reactance of the grid connection point to the bus line, P t is the active power of the grid-connected point load during period t, Q t is the reactive power of the grid-connected point load during period t, Q PV,t is the photovoltaic grid-connected reactive power in period t; The expression for determining the voltage fluctuation risk of the distributed photovoltaic grid-connected common coupling point is: ΔU PCC,t ≤U PVref,PCC ΔS=P PV +jQ PV In the formula, ΔU PCC,t is the voltage fluctuation of the photovoltaic grid-connected common coupling point during period t, U PVref,PCC is the allowable value of the grid-connected point reference voltage, S N is the rated apparent power of the line, U N is the line rated voltage, ΔS is the apparent power change after photovoltaic access, is the impedance angle of the system equivalent impedance, θ is the photovoltaic power source power factor angle, and j is the imaginary unit; The expression for determining the harmonic risk of distributed photovoltaic grid-connected power generation is: In the formula, is the harmonic current generated by the photovoltaic system at the grid-connected point during period t, is the harmonic current reference value, is the photovoltaic current at the grid-connected point, Z eq,load is the equivalent wave impedance of the grid-connected load, Z eq,grid is the equivalent wave impedance on the grid side, is the harmonic voltage generated by the photovoltaic system at the grid-connected point during period t, is the harmonic voltage reference value, is the harmonic current generated by the photovoltaic system at the grid-connected point during period t, Z k is the line impedance of the adjacent load node when the filter element is not considered, Z L is the adjacent load impedance when filtering elements are not taken into account, and n is the total number of nodes in the distribution network.

5. A two-layer optimization method for operation of a fishery-solar-storage complementary system according to claim 4, characterized in that: If any of the risk judgment of voltage deviation caused by distributed photovoltaic grid connection, the risk judgment of voltage fluctuation at the common coupling point of distributed photovoltaic grid connection, and the risk judgment of harmonics of distributed photovoltaic grid connection is not met, the judgment condition is deemed not to be met.

6. A two-layer optimization method for operation of a fishery-solar-storage complementary system according to claim 2, characterized in that: The expression for increasing the abandoned light rate in the process of calculating the upper layer objective function is: oh pv,t =ω pv,t +See pv In the formula, Δω pv It is a micro increment of the unit light abandonment rate.

7. A two-layer optimization method for operation of a fishery-solar-energy-storage complementary system according to claim 2, characterized in that: In the fishery-solar-storage complementary system model, the calculation expression of the total power consumption of the system is: W D (t)=W fee (t)+W oxy (t)+W pum (t)+W other (t) Where W D (t) is the total power consumption of the fishery-solar-storage complementary system, W fee (t) is the power consumption of the bait feeding equipment, W oxy (t) is the power consumption of the oxygenation equipment, W pum (t) is the power consumption of irrigation and drainage equipment, W other (t) is the electricity consumption other than that of the breeding equipment; Where P fee is the power of the bait throwing equipment, k f is the number of bait placements, S f is the bait placement distance, V f is the bait delivery speed, P oxy is the power of the oxygen enrichment equipment, t o is the working time of the oxygen enrichment equipment, P pum is the power of irrigation and drainage equipment, k p is the frequency of fish farm water replacement, n ac is the scale of fish farm, h p is the water change height, y p is the aerator water pump flow.

8. The double-layer optimization method for operation of a fishery-solar-storage complementary system according to claim 1, characterized in that: The expression of the lower objective function of the low-carbon economic operation of the fishery-solar-storage complementary system considering the carbon emissions and the lowest comprehensive operating cost is: minF2=C1+C2+C3+C4-C5 Where F2 is the lower objective function of the low-carbon economic operation of the fishery-solar-energy-storage complementary system considering the lowest carbon emissions and comprehensive operating costs; C1 is the operating cost of the photovoltaic system; C2 is the operating and maintenance cost of the energy storage device; C3 is the carbon trading cost of the system; C4 is the power purchase cost of the grid; and C5 is the income from photovoltaic grid connection.

9. A two-layer optimization method for operation of a fishery-solar-storage complementary system according to claim 8, characterized in that: The calculation expression of the photovoltaic system operating cost of the system is: In the formula, ρ pv is the photovoltaic system operation and maintenance cost coefficient, P pv,t is the photovoltaic power generation power of the system in period t, and T is the total daily cycle; The calculation expression of the operation and maintenance cost of the energy storage device of the system is: In the formula, ρ soc is the operation and maintenance cost coefficient of the energy storage device, P soc,t is the charging power of the energy storage system during period t, P d,t is the discharge power of the energy storage system during period t, P c,t The charging power of the energy storage system during period t; The calculation expression of the system carbon trading cost is: Where d is the carbon capture cost coefficient, P buy,t is the amount of electricity purchased from the power grid during period t, Δt is the time interval between periods, C i is the coal consumption coefficient per unit of electricity; The calculation expression of the power purchase cost of the system grid is: In the formula, p grid,t is the electricity selling price of the distribution network during period t; The calculation expression of the photovoltaic grid-connected income is: In the formula, p pvout,t is the photovoltaic grid-connected purchase price during period t, P pvout,t is the photovoltaic grid-connected power of the system during period t.

10. The double-layer optimization method for operation of a fishery-solar-storage complementary system according to claim 1, characterized in that: The expression of the system power balance constraint is: P buy,t +P pv,t +P d,t =P D,t +P c,t +P pvout,t Where P buy,t P is the amount of electricity purchased from the power grid during period t. pvout,t is the photovoltaic grid-connected power of the system during period t, P d,t is the discharge power of the energy storage system during period t, P c,t is the charging power of the energy storage system during period t, P D,t is the net load of the system during period t, P pv,t is the photovoltaic power of the system during period t; The expression of the transmission line capacity constraint is: 0<P buy,t <P Lmax Where P Lmax is the maximum transmission power of the transmission line.

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