A low-carbon port microgrid with self-powered energy and its distributed energy management method

Abstract

This invention discloses a low-carbon port microgrid with self-generated energy, comprising: wind power self-generated energy, photovoltaic self-generated energy, traditional self-generated energy, energy storage self-generated energy, ship self-generated energy, and AC busbars; a distributed energy management method for the low-carbon port microgrid with self-generated energy, including: analyzing and establishing the power generation cost function of the self-generated energy equipment in the port microgrid; constructing the operating cost function of the self-generated energy based on rotation symmetry; considering constraints such as load supply and demand balance constraints and self-generated energy equipment capacity constraints in the port microgrid, constructing an energy management model for the low-carbon port microgrid with self-generated energy; and solving the energy management problem of the low-carbon port microgrid with self-generated energy based on a distributed consensus algorithm to obtain the optimal operation scheme of the low-carbon port microgrid with self-generated energy. This invention can achieve low-carbon, green, and sustainable development of ports.

Description

Technical Field

[0001] This invention belongs to the field of energy management technology for energy conservation, emission reduction, and promoting the high proportion of clean energy utilization in all-electric ships and port microgrids, specifically involving an energy management method for low-carbon port microgrids with self-powered energy. Background Technology

[0002] Currently, after ships dock, they either rely on ship generators to consume fossil fuels to provide electricity or connect to shore power systems. However, using ship generators to power ships not only fails to utilize clean energy but also causes noise and environmental pollution problems for ports. In response to the national call for carbon neutrality and carbon emission reduction, and to establish green and smart new ports, it is urgent to improve the use of clean energy in ports, promote the use of all-electric ships and shore power through shore power systems, reduce port carbon emissions, develop low-carbon port microgrids, and study their energy management issues.

[0003] Port energy management is a constrained optimization problem. Currently, most ports employ centralized methods to address energy management. However, port microgrids possess the potential to utilize clean energy and incorporate various types of self-generated energy sources, resulting in a distributed structure. Therefore, it is necessary to design a distributed energy management method suitable for port microgrids containing self-generated energy sources such as ship-generated energy.

[0004] Researchers have achieved some results in addressing the energy management problem of port microgrids, considering the integration of renewable energy sources and shore power supply to ships. However, self-energy models have been studied in some regions to achieve on-site consumption of electricity generated from clean energy sources. Port microgrids with self-energy sources exhibit a distributed structure, making centralized energy management methods unsuitable. Therefore, a solution method that can achieve consistency in the marginal costs of individual energy sources is needed. Thus, designing a solution applicable to the energy management of port microgrids containing self-energy sources such as ship self-energy is a challenging problem. Summary of the Invention

[0005] To address the above problems, the present invention provides a technical solution: a low-carbon port microgrid with self-powered energy, comprising:

[0006] Wind energy is a self-sustaining energy source that uses wind turbines to generate electricity for load systems.

[0007] Photovoltaic self-energy, which uses photovoltaic equipment to generate solar power to provide electricity to load systems.

[0008] Traditional self-sustaining energy sources that generate electricity using conventional power generation equipment to provide power to load systems.

[0009] Energy storage self-storage energy source that uses stored electrical energy to provide power to load systems.

[0010] Ship self-powered systems, AC busbars, and main power grids utilize clean energy through power generation equipment to provide electricity to the ship itself.

[0011] The wind power, photovoltaic power, and traditional power are all connected in parallel to one side of the AC busbar.

[0012] The energy storage power source, the main power block, and the ship's power source are indirectly connected in parallel to the other side of the AC busbar.

[0013] A distributed energy management method for a low-carbon port microgrid with self-powered energy sources includes the following steps:

[0014] Analyze the structure of self-powered energy sources in the port microgrid and analyze the power generation cost function of self-powered energy production equipment.

[0015] Considering the bidirectional energy interaction characteristics of self-energy sources, the composition of the operating cost of a single self-energy source is analyzed, and the operating cost function of a single self-energy source is established; then, based on the rotation symmetry, the operating cost function of the self-energy source is constructed, and the operating cost function of the port microgrid with self-energy sources is established.

[0016] Considering the constraints of load supply and demand balance and self-energy production capacity of port microgrids, an energy management model for low-carbon port microgrids with self-energy is constructed.

[0017] The energy management problem of low-carbon port microgrids with self-powered energy sources is solved based on the distributed consensus algorithm, and the optimal operation scheme of low-carbon port microgrids with self-powered energy sources is obtained.

[0018] Furthermore: the power generation cost function of the self-energy generating equipment:

[0019] f = C ok (P k (1)

[0020] In the formula, C ok (P k ) = a k P k 2 +b k P k +c k and C ok (P k ) = a k (P k +b k ) 2 Let a represent the power generation cost functions of the energy storage equipment in non-energy storage self-energy sources and energy storage self-energy sources, respectively.k b k and c k These represent the power generation cost coefficients of the equipment; C ok (P k ) needs to go through The relationship is transformed into P. rk The power generation cost function C is a variable ok (P rk ), P rk It is the marginal cost of energy k.

[0021] Furthermore, the operating cost of the single self-powered energy source and the operating cost of the low-carbon port microgrid with self-powered energy source are expressed as follows:

[0022] f(P rk ) = C ok (P rk )+C ot (P rk )+C rm (P mk )+C emk (P rk (2)

[0023]

[0024] In equation (2), C ok (P rk C is the cost of generating electricity from self-powered equipment; ot (P rk ) represents the energy exchange cost between the self-generated energy source k and its neighbors in the port microgrid; C rm (P mk P represents the cost arising from the interaction between self-generated energy and the main grid's electrical energy; mk C is the amount of electricity that energy source k obtains from the main power grid; emk (P rk ) is the carbon emission cost of self-sourced energy k. In equation (3), N is the quantity of self-sourced energy at the port; eco is the unit carbon emission cost; m is the quantity of traditional self-sourced energy. It is the carbon emissions generated by traditional self-energy sources; P rg It is the main grid electricity price; P MG It refers to the electricity supplied by the main power grid to the port's microgrid.

[0025] Furthermore: the energy management model for the low-carbon port microgrid with self-powered energy:

[0026]

[0027] In the formula, the first inequality applies when the self-energy source k is a non-storage self-energy source; the second inequality applies when the self-energy source k is a storage self-energy source. It is the sum of the total electricity generated by N self-generated energy sources; P de It is the total power consumption of the load devices in the port microgrid; and These represent the lower and upper limits of the output capacity of the respective energy-producing equipment; and These are the lower and upper limits of the charging and discharging capacity of energy storage devices in energy storage self-sufficiency systems, respectively; P e This refers to the rated capacity of the energy storage device.

[0028] Further, in a low-carbon port microgrid with self-powered energy sources, where each self-powered energy source is a node, a distributed consensus algorithm is used to solve the energy management problem of the low-carbon port microgrid with self-powered energy sources, and to obtain the optimal operation scheme of the low-carbon port microgrid with self-powered energy sources. The specific steps are as follows:

[0029] Step 4.1: Set initial parameters and initialize the marginal cost of each energy source; set the total number of iterations s and the iteration step size α in this optimization process;

[0030] Step 4.2: s = s + 1, each self-energy source updates the value of its marginal cost according to the distributed consensus algorithm;

[0031] Step 4.3: If the marginal cost of energy obtained is greater than the upper limit of marginal cost, take the upper limit of marginal cost; if the marginal cost of energy obtained is less than the lower limit of marginal cost, take the lower limit of marginal cost; otherwise, take the updated marginal cost.

[0032] Step 4.4: When each energy production equipment meets the constraints such as capacity constraints and power supply and demand balance constraints of the port microgrid, and the marginal cost of each energy source reaches a consistency, then the marginal cost of each energy source and the power output of the production equipment are obtained, and the optimal operation scheme of the low-carbon port microgrid with its own energy source is also obtained; otherwise, if the updated marginal cost is not the optimal solution to the energy management problem of the port microgrid, if the number of iterations is not greater than s, return to step 4.2 and update the marginal cost again; if the number of iterations is greater than s, complete s iterations and reset the number of iterations s.

[0033] This invention provides an energy management method for a low-carbon port microgrid with self-powered energy. The provided low-carbon port microgrid with self-powered energy integrates clean energy power generation and traditional energy power generation, establishes an objective function including the self-powered energy operating cost, carbon emission cost and the cost of purchasing electricity for the port microgrid, and constructs a port microgrid energy management model. The economic and environmental benefits of the port microgrid are achieved through a distributed approach.

[0034] For energy management of low-carbon port microgrids with self-powered energy sources, this invention not only analyzes the distributed structure of port microgrids containing self-powered energy sources such as all-electric ships and the characteristics of bidirectional energy transmission between neighboring self-powered energy sources, but also establishes a self-powered energy operating cost function with marginal cost as the variable. Then, it constructs a port microgrid energy management model and proposes a distributed energy management strategy based on a distributed consensus solution method.

[0035] This invention uses marginal cost as a variable to establish a distributed solution method to solve the energy management problem of low-carbon port microgrids with self-powered energy sources. This invention integrates existing port structures such as the main power grid, clean energy, and all-electric vessels, and establishes a port microgrid energy management model with self-powered energy sources as the core, ensuring the stable and economical operation of the port microgrid and achieving low-carbon, green, and sustainable development. The distributed solution method is used to solve the port microgrid energy management problem, achieving the goal of optimal operating costs. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This invention provides a self-powered, low-carbon port microgrid structure;

[0038] Figure 2 Flowchart of distributed energy management for a low-carbon port microgrid with self-powered energy;

[0039] Figure 3 This invention provides a multi-modal energy management system for port microgrids;

[0040] Figure 4 A schematic diagram of the communication topology of a port microgrid with self-powered energy is provided for this invention.

[0041] Figure 5 This invention provides a schematic diagram of the marginal cost output trajectory of each port's energy based on the self-energy model, considering supply and demand balance and capacity constraints.

[0042] Figure 6 This invention provides an output power curve diagram of the self-powered energy production equipment in a port microgrid. Detailed Implementation

[0043] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0046] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0047] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0048] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0049] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0050] To address port environmental pollution and establish low-carbon ports primarily powered by clean energy, this invention provides a low-carbon port microgrid with self-generated energy and a distributed energy management method. The port microgrid, composed of wind power, photovoltaic power, traditional energy sources, and ship power, achieves efficient utilization of electricity and low-carbon port development. Furthermore, the distributed energy management technology employed in this invention utilizes regionalized energy resources to optimize the operating costs of the port microgrid.

[0051] Combination Figure 1 The diagram shows a low-carbon port microgrid structure with self-powered energy provided by the present invention. The structure includes: a main grid, wind power self-powered energy, shore power system, ship self-powered energy, photovoltaic self-powered energy, traditional self-powered energy, energy storage self-powered energy, and AC busbar. It can fully utilize clean energy and also meet the load supply and demand balance of the port microgrid.

[0052] To make the structure and advantages of this invention more easily understood, the following will be combined with... Figure 1 Detailed introduction to the structure of port microelectronics:

[0053] like Figure 1 As shown, the port microgrid structure with self-powered energy of the present invention includes: a main grid, wind self-powered energy, shore power system, ship self-powered energy, photovoltaic self-powered energy, traditional self-powered energy, energy storage self-powered energy, and AC busbar.

[0054] The wind energy self-energy utilizes wind turbine equipment to generate wind power and provide electrical energy to the load system;

[0055] The photovoltaic self-energy utilizes photovoltaic equipment to generate solar power and provide electrical energy to the load system;

[0056] The aforementioned traditional self-energy uses traditional power generation equipment to generate electricity and provide power to the load system;

[0057] The energy storage system utilizes the electrical energy stored in the energy storage device to provide power to the load system.

[0058] The ship's self-powered system utilizes clean energy through power generation equipment to provide electricity for the ship itself.

[0059] The wind power, photovoltaic power, and traditional power are all connected in parallel to one side of the AC busbar.

[0060] Both the shore power system and the energy storage self-powered energy source are connected in parallel to the other side of the AC busbar;

[0061] The main power grid and the ship's self-powered energy source are indirectly connected in parallel to the other side of the AC busbar;

[0062] The shore power system is connected to the ship's self-powered power source via a transmission line on the other side.

[0063] (1) Main power grid

[0064] The main power grid includes the main power grid, the first conversion module, and the detection module;

[0065] The main power grid is connected in sequence to the first conversion module and the detection module;

[0066] When the energy production capacity of each component in the port microgrid is insufficient, the main power grid provides power to the port microgrid through the AC busbar.

[0067] The first conversion module is connected to the main power grid at one end and is used to change the voltage and current.

[0068] One end of the detection module is connected to the conversion module, and the other end of the detection module is connected to the AC busbar. It is used to detect the voltage, current, and power transmission amount to the port microgrid, as well as to detect the continuity of the lines connected to the AC busbar.

[0069] The main power grid, the first conversion module, and the detection module are connected in series with the port microgrid via long-distance transmission lines. When their respective energy production equipment cannot meet the power consumption requirements of the load equipment, they can directly provide power through the main power grid. When the all-electric ship is regarded as the load, its required power can be provided by the main power grid.

[0070] (2) Wind energy self-sufficiency

[0071] The wind energy self-powered energy source includes wind power equipment and a first detection and control submodule;

[0072] The wind energy self-energy source is directly connected to the AC busbar through the first detection and control submodule, and can perform bidirectional electrical energy interaction with other self-energy sources.

[0073] The first detection and control submodule includes devices such as voltage boosting and bucking equipment and power detection equipment, which are used to control the rise or fall of voltage and the strength or weakness of current flowing out of or into the wind energy source.

[0074] The wind energy self-powered energy source includes at least power generation equipment and load equipment, specifically described as wind turbine equipment, detection and control module and load system, which are connected in sequence;

[0075] The purpose of the wind turbine equipment is to provide electrical energy to the wind energy source.

[0076] The first detection sub-control module includes devices such as controllers and wind turbine inverters, which are used to control and detect the output voltage or current of the wind turbine equipment.

[0077] Wind energy self-sufficiency equipment has the characteristics of self-sufficiency and multiple uses, and plays a role in regional autonomy. Through the connection of detection module and AC bus, it can exchange electrical energy with neighboring self-sufficiency energy sources and realize bidirectional power transmission.

[0078] The load system consists of loads such as electric vehicles, automated guided vehicles, port lighting equipment, and cold storage facilities;

[0079] The load system and the first detection and control submodule are connected in series with the wind turbine equipment to consume the electrical energy generated by the wind turbine equipment.

[0080] (3) Shore power system

[0081] The shore power system consists of shore power transmission piles, distribution inverters, frequency converters, air circuit breakers and other equipment, ensuring that the port and ships can transmit electricity in both directions.

[0082] The shore power system can not only control the on / off of the lines connecting to the ship, but also be used to change the voltage frequency, etc.

[0083] It also includes an eighth detection and control module;

[0084] One end of the eighth detection and control module is connected to the shore power system to change the direction of current flow and detect the ship's use of shore power for its own power source. The other end of the eighth detection and control module is connected to the ship's own power source.

[0085] (4) Ship self-powered

[0086] When a ship is moored at its own power source, it can rely on generators to consume clean energy sources such as methanol, methane, and LNG to generate electricity to power the ship. This provides regional autonomy and ensures the operation of some or all of the ship's lighting, propulsion, energy storage, and other systems.

[0087] (5) Photovoltaic self-energy

[0088] The photovoltaic self-powered energy mainly consists of photovoltaic equipment, a load system, and a third control and detection module.

[0089] The photovoltaic self-energy source is directly connected to the AC busbar through the third sub-detection and control module, and can perform bidirectional power exchange with neighboring self-energy sources.

[0090] The third detection and control submodule includes devices such as voltage boosting / buckling equipment and power detection equipment, which are used to control the voltage rise or fall and the current strength or weakness of the photovoltaic self-energy flowing out or into the photovoltaic self-energy.

[0091] Photovoltaic equipment is used to provide electricity to photovoltaic self-generated energy sources;

[0092] The third detection and control submodule includes devices such as controllers and photovoltaic inverters, which are used to control and detect the output voltage or current of photovoltaic equipment.

[0093] The load system and the third detection and control module are connected in series to the other end of the photovoltaic device to consume the electrical energy generated by the photovoltaic device.

[0094] Photovoltaic self-energy consists of solar photovoltaic panels, which are characterized by self-sufficiency and multi-use, and have the function of regional autonomy. It can exchange electrical energy with neighboring self-energy sources through the third detection and control submodule and AC busbar, and realize bidirectional power transmission.

[0095] (6) Traditional self-energy

[0096] Traditional self-sufficient energy sources include thermal power generation equipment. When the thermal power generation equipment meets environmental indicators, it consumes traditional energy to generate electricity. Traditional self-sufficient energy sources are characterized by self-sufficiency and multiple uses, and have the function of regional autonomy. Through the connection of detection modules and AC busbars, they can exchange electrical energy with neighboring self-sufficient energy sources to achieve bidirectional transmission of electrical energy.

[0097] The traditional self-powered energy source is directly connected to the AC busbar through the detection and control module, and can perform bidirectional power exchange with neighboring self-powered energy sources.

[0098] The detection and control module includes devices such as voltage boosting / buckling equipment and power detection equipment, which are used to control the voltage rise or fall and the current strength or weakness of the traditional self-source energy flowing out or into it.

[0099] The aforementioned traditional self-energy mainly consists of thermal power generation equipment, load system, and control and detection module; the thermal power generation equipment consumes traditional energy to generate electricity under the condition of meeting environmental indicators;

[0100] The load system and detection and control module are connected in series to the other end of the thermal power generation equipment to consume the electrical energy generated by the thermal power generation equipment.

[0101] The detection and control module includes devices such as controllers and AC-DC inverters, which are used to control and detect the output voltage or current of thermal power generation equipment.

[0102] (7) Energy storage from energy sources

[0103] Energy storage devices in the energy sector are used to store electrical energy or provide electrical energy to load systems;

[0104] Energy storage devices are characterized by self-sufficiency and multiple uses, and have the function of regional autonomy. The second conversion module is used to change the current transmitted to the load and to detect the output power of the energy storage device.

[0105] The energy storage self-energy source is directly connected to the AC busbar through the ninth detection and control module, and can perform bidirectional power exchange with neighboring self-energy sources.

[0106] The second conversion module includes equipment such as step-up and step-down devices and rectifiers, which are used to control the AC-DC conversion and the rise or fall of the voltage and the strength or weakness of the current flowing out of or into the energy storage source.

[0107] The energy storage self-energy source includes an energy storage device, a ninth detection and control module, and a load system, which are connected in sequence; the energy storage device is used to store electrical energy or provide electrical energy to the load system.

[0108] The ninth detection and control module includes devices such as a controller and a rectifier, used to change the current transmitted to the load and detect the output power of the energy storage device; the load system includes lighting equipment, etc., which are connected in series with the detection and control module and connected to the other end of the energy storage device.

[0109] (8) AC busbar

[0110] The AC busbars in the port microgrid are responsible for receiving and transmitting electrical energy from the main grid and their respective energy sources;

[0111] The main power grid and the various self-energy sources can exchange electrical energy bidirectionally with neighboring self-energy sources through the AC busbar, while promoting the high proportion of clean energy use and building a green and low-carbon port microgrid.

[0112] The main functions of the detection and control module are: real-time acquisition of energy production and consumption information, real-time control of AC voltage rise and fall, and control of current frequency during power transmission.

[0113] The independent energy sources give the port microgrid a distributed characteristic. By adopting a distributed energy management strategy, the port microgrid can realize the self-generation and self-use, multi-generation and multi-use, and intelligent management of regional energy.

[0114] A distributed energy management method for low-carbon port microgrids with self-powered energy sources. Figure 2 This is a flowchart of distributed energy management for a low-carbon port microgrid with self-powered energy, combined with... Figure 2 This energy management problem is solved using a distributed consensus method based on a multi-agent system. Since the energy sources are located in different communication networks, traditional communication networks cannot achieve information exchange between neighboring energy sources. Therefore, an energy management system for the port microgrid is established based on a multimodal network, such as... Figure 3 As shown, reliable information exchange is achieved between neighboring energy sources; specifically, the following steps are included:

[0115] Step 1: Analyze the structure of self-energy sources in the port microgrid to obtain the power generation cost function of the self-energy source's generating equipment:

[0116] f = C ok (P k (1)

[0117] In the formula, C ok (P k ) = a k P k 2 +b k P k +c k and C ok (P k ) = a k (P k +b k ) 2 Let a represent the power generation cost functions of the energy storage equipment in non-energy storage self-energy sources and energy storage self-energy sources, respectively. k b k and c k These represent the power generation cost coefficients of the equipment; C ok (P k ) needs to go through The relationship is transformed into P. rk The power generation cost function C is a variable ok (P rk ), P rk It is the marginal cost of energy k.

[0118] Step 2: First, considering the bidirectional energy interaction characteristics of self-generated energy sources, analyze the composition of the operating cost of a single self-generated energy source and establish its operating cost function. Second, construct the operating cost function of the self-generated energy source based on rotation symmetry. Finally, establish the operating cost function of the port microgrid with self-generated energy sources.

[0119] The bidirectional energy transfer behavior of self-generated energy sources complicates the cost, including not only the cost of generating electricity but also the costs of energy interaction between self-generated energy sources. The operating cost of a single self-generated energy source in a port microgrid includes: the generation cost of various energy-producing devices, the fees paid for energy transfer with neighbors and the main grid, and the fees earned from selling electricity to neighbors and the main grid. The operating cost of a single self-generated energy source is expressed as:

[0120]

[0121] In the formula, C ok (P rk P is the cost of generating electricity from self-sufficient energy production equipment; k→j It is the electrical energy provided by self-energy k to self-energy j, a kj It is the electrical energy provided; C rm (P mk P represents the cost arising from the interaction between self-generated energy and the main grid's electrical energy; mk Represented as C is the amount of electricity that energy source k obtains from the main power grid; emk (P rk ) is the carbon emission cost of self-energy k.

[0122] Based on the unique symmetry structure of the cost of energy exchange between the self-energy source k and its neighbors, and leveraging this rotational symmetry, the operating cost of the self-energy source is constructed. Finally, the operating cost of the low-carbon port microgrid with its self-energy source is obtained:

[0123]

[0124] In the formula, N represents the amount of self-generated energy in the port microgrid; eco is the unit carbon emission cost, which is 1 yuan; and m is the amount of traditional self-generated energy. It is the carbon emissions generated by traditional self-energy sources; P rg It is the main grid electricity price; P MG It is the electricity supplied by the main power grid to the port microgrid; the power generation cost and carbon emissions of self-powered energy production equipment can both be represented by quadratic functions.

[0125] The term "single self-sustaining energy source" refers to wind power self-sustaining energy, ship self-sustaining energy, photovoltaic self-sustaining energy, traditional self-sustaining energy, and energy storage self-sustaining energy.

[0126] Step 3: The port microgrid has N self-powered energy sources. Considering the constraints such as load supply and demand balance constraints and self-powered energy production capacity constraints in the port microgrid, construct a low-carbon port microgrid energy management model with self-powered energy sources.

[0127]

[0128] In the formula, the first inequality applies when the self-energy source k is a non-storage self-energy source; the second inequality applies when the self-energy source k is a storage self-energy source. It is the sum of the total electricity generated by N self-generated energy sources; P de It is the total power consumption of the load devices in the port microgrid; and These represent the lower and upper limits of the output capacity of the respective energy-producing equipment; and These are the lower and upper limits of the charging and discharging capacity of energy storage devices in energy storage self-sufficiency systems, respectively; P e This refers to the rated capacity of the energy storage device.

[0129] This application studies the energy management problem of port microgrids using marginal cost as the variable; however, the above constraints are based on the power generation P. k To describe the variables, it is necessary to use marginal cost P to ensure the uniformity of variables in the energy management problem of port microgrids. rk and power generation P k Relationship To perform the transformation, that is:

[0130] P rk =2*a k *P k +b k (5)

[0131] Based on this example, according to Figure 4 The diagram shows the communication topology of a low-carbon port microgrid, which enables information exchange between energy sources. Nodes 1, 6, 7, and 8 represent clean energy sources, nodes 2 and 3 represent energy storage energy sources, nodes 4 and 5 represent traditional energy sources, and nodes 9 and 10 represent ship energy sources. The grid electricity price is 0.8 yuan, and the total port load power demand is 41571W.

[0132] Step 4: Solve the energy management problem of low-carbon port microgrids with self-powered energy based on the distributed consensus algorithm, and obtain the optimal operation scheme of low-carbon port microgrids with self-powered energy.

[0133] To address the energy management problem in port microgrids, a distributed consensus solution method is designed. In a low-carbon port microgrid with self-powered energy sources, each self-powered energy source is considered a node. Corresponding changes are made to the equality constraints, such that P... deThe energy is evenly distributed among N self-generated energy sources. The equality constraints are transformed into the objective function using the following algorithm:

[0134]

[0135] Where g(.) represents the mapping relationship; This represents the gradient of the energy cost function or carbon emission function; α, taking 0.00000009, is the update step size (a positive number), different step sizes will affect the reliability of the algorithm; L is the Laplacian matrix; z k,s It is an auxiliary variable for updating the marginal cost of energy k in the s-th step, and the number of iterations s is taken as 1,000,000 for simulation research.

[0136] Step 4.1: Set initial parameters and initialize the marginal cost of each energy source; set the total number of iterations s and the iteration step size α in this optimization process;

[0137] Step 4.2: s = s + 1, each self-energy source updates the value of its marginal cost according to the distributed consensus algorithm;

[0138] Step 4.3: If the marginal cost of energy obtained is greater than the upper limit of marginal cost, take the upper limit of marginal cost; if the marginal cost of energy obtained is less than the lower limit of marginal cost, take the lower limit of marginal cost; otherwise, take the updated marginal cost.

[0139] Step 4.4: When each energy production equipment meets the constraints such as capacity constraints and power supply and demand balance constraints of the port microgrid, and the marginal cost of each energy source reaches a consistency, then the marginal cost of each energy source and the power output of the production equipment are obtained, and the optimal operation scheme of the low-carbon port microgrid with its own energy source is also obtained; otherwise, if the updated marginal cost is not the optimal solution to the energy management problem of the port microgrid, if the number of iterations is not greater than s, return to step 4.2 and update the marginal cost again; if the number of iterations is greater than s, complete s iterations and reset the number of iterations s.

[0140] This invention addresses the energy management problem of low-carbon port microgrids based on the proposed distributed consensus algorithm.

[0141] Figure 5 This invention provides a schematic diagram of the marginal cost output trajectory of each port's energy based on the self-energy model, considering supply and demand balance and capacity constraints.

[0142] Figure 6 This invention provides an output power curve diagram of the port microgrid's self-powered energy production equipment;

[0143] Figure 5 and Figure 6These figures represent the trajectory of achieving consistency in the marginal cost of self-energy over time and the output power curve of self-energy-producing equipment, respectively. This method can solve the energy management problem of low-carbon port microgrids with self-energy.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-carbon port microgrid with self-energy source, characterized in that: The wind energy self-energy includes: A wind energy self-energy using a fan device to generate wind power and provide electric energy for a load system, A photovoltaic self-energy using a photovoltaic device to generate solar power and provide electric energy for a load system, A traditional self-energy using a traditional power generation device to generate power and provide electric energy for a load system, A storage self-energy using a storage device to store electric energy and provide electric energy for a load system, A ship self-energy using a clean energy generation device to provide electric energy for a ship itself, an AC bus row, and a main power grid. The wind energy self-energy, the photovoltaic self-energy, and the traditional self-energy are connected in parallel to one side of the AC bus row. The storage self-energy, the main power grid, and the ship self-energy are indirectly connected in parallel to the other side of the AC bus row. A distributed energy management method of a low-carbon port microgrid with self-energy includes the following steps: Analyzing the structure of the self-energy in the port microgrid and analyzing the power generation cost function of the self-energy power generation device; Considering the characteristics of the two-way interaction of the self-energy, analyzing the operation cost composition of a single self-energy, and establishing the operation cost function of the single self-energy; further, based on the rotational symmetry, the operation cost function of the self-energy is constructed, and the operation cost function of the port microgrid with self-energy is established; Considering the load supply and demand balance constraint and the self-energy power generation device capacity constraint of the port microgrid, the low-carbon port microgrid energy management model with self-energy is constructed; Based on the distributed consistency algorithm, the low-carbon port microgrid energy management problem with self-energy is solved, and the optimal operation scheme of the low-carbon port microgrid with self-energy is obtained; The power generation cost function of the self-energy power generation device is: （1） In the formula, and respectively represent the non-energy storage self-energy and energy storage self-energy power generation cost function, respectively represent the power generation cost coefficient of the power generation device; need to go through relationship, into the power generation cost function with as the variable , is the marginal cost of the self-energy k; is the power generation capacity; In the low-carbon port microgrid with self-energy, each self-energy is a node, and the distributed consistency algorithm is used to solve the energy management problem of the low-carbon port microgrid with self-energy, and the optimal operation scheme of the low-carbon port microgrid with self-energy is obtained, In the low-carbon port micro-grid with self-energy, each self-energy is a node, and the corresponding changes are made in the equality constraint. The total power consumption of the load equipment in the port micro-grid is The average is allocated to N self-energy, and the equality constraint condition is converted to the objective function, and the following algorithm is adopted: (6) wherein, is a mapping relationship; denotes the gradient of the self-energy cost function or the carbon emission function; takes 0.00000009 as an update step, and different steps will affect the reliability of the algorithm; L is a Laplacian matrix; is a self-energy k auxiliary variable for updating the marginal cost in the s-th step; The specific steps are as follows: Step 4.1: Set initial parameters, initialize the marginal cost of each energy source; set the total number of iterations s in this optimization process, and the iteration step size ; Step 4.2: s=s+1, each self-energy updates the value of the marginal cost according to the distributed consistency algorithm; Step 4.3: if the obtained marginal cost of the self-energy is greater than the upper limit of the marginal cost, the upper limit of the marginal cost is taken; if the obtained marginal cost of the self-energy is less than the lower limit of the marginal cost, the lower limit of the marginal cost is taken; otherwise, the updated marginal cost is taken; Step 4.4: when the self-energy power generation device satisfies the capacity constraint and the port microgrid electric energy supply and demand balance constraint, and the marginal cost of each self-energy reaches consistency, the marginal cost of each self-energy and the output electric energy of the self-energy power generation device are obtained, and the optimal operation scheme of the low-carbon port microgrid with self-energy is obtained; otherwise, the updated marginal cost is not the optimal solution of the port microgrid energy management problem, and if the iteration number is not greater than s, the marginal cost is updated again; if the iteration number is greater than s, s iterations are completed, and the iteration number s is reset.

2. The method of claim 1, wherein the method further comprises: The operation cost of the single self-energy and the operation cost of the low-carbon port microgrid with self-energy are expressed as follows: （2） （3） In formula (2), is the generation cost of the self-energy production device; is the cost of the power exchange between the self-energy k and the neighbors in the port microgrid; is the cost of the power exchange between the self-energy and the main grid; is the power obtained by the self-energy k from the main grid; is the carbon emission cost of the self-energy k; In formula (3), N is the amount of port self-energy; eco is the unit carbon emission cost; m is the amount of traditional self-energy, is the carbon emission amount generated by traditional self-energy; is the main grid electricity price; is the amount of electricity provided by the main grid to the port micro-grid.

3. The method of claim 2, wherein the method further comprises: The low-carbon port microgrid energy management model with self-energy is: （4） In the formula, the first inequality is when the self-energy k is a non-energy storage self-energy; the second inequality is when the self-energy k is an energy storage self-energy; is the sum of the total power generated by the n self-energies; N is the sum of the total power consumed by the load devices in the port micro-grid; is the sum of the total power consumed by the load devices in the port micro-grid; and respectively represent the lower limit and the upper limit of the output of the power generation device in each self-energy; and respectively represent the lower limit and the upper limit of the charge and discharge capacity of the energy storage device in the energy storage self-energy; is the rated capacity of the energy storage device.

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