Rural'wind-solar-biogas storage 'multi-energy complementary power supply system and scheduling optimization method

Abstract

The invention relates to a rural multi-energy complementary power supply system with'wind, light and biogas storage 'and a scheduling optimization method. An energy management system is connected with a power generation unit, an energy storage unit, a load unit and a standby power supply. Parameters in the scheduling optimization model are perfected according to the constraint conditions and the objective function, the configuration scheme is an optimization algorithm, the scheduling optimization model is simulated by using the algorithm to obtain an optimal scheduling strategy, and the optimal scheduling strategy can be obtained by combining specific conditions of rural areas. Power is continuously generated through the biogas power generation system, the wind power generation system and the photovoltaic power generation system, the stability, reliability and economical efficiency of the power supply system are considered, and the utilization efficiency of rural resources is improved. The power generation cost can be reduced to the maximum extent, the utilization rate of clean energy is increased, and environmental pollution is reduced while the rural power utilization requirement is met. And the multi-energy complementary power supply system is also matched with the large power grid, so that surplus electric energy is sold to the large power grid on the premise of meeting the load requirement, and reasonable utilization of resources is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation of electric power systems, and in particular to a rural "wind, solar, storage and biogas" multi-energy complementary power supply system and a dispatching optimization method. Background Art

[0002] Electricity users in rural areas of my country have increasingly higher requirements for grid reliability.

[0003] At present, the stability of the rural power supply system is affected to a certain extent due to aging lines, insufficient equipment, and long power supply lines, resulting in the inability of the rural power supply system to meet the electricity needs of rural users. At the same time, as a country with a large coal reserve, my country has a lower economic cost of investing in thermal power generation, which has led to the rural power supply structure being dominated by thermal power. For a long time, this form of power supply structure has also brought serious environmental pollution problems.

[0004] In the existing technology, most of the existing multi-energy complementary power supply systems are used to meet the electricity needs of offshore oil fields or remote islands. They are generally based on tidal energy and solar power generation. Their application scenarios are single, their replicability and operability are not strong, and their investment costs are high. Summary of the invention

[0005] The purpose of the present invention is to provide a rural "wind, solar, storage and biogas" multi-energy complementary power supply system, which can be used in remote rural areas, has low investment cost and low installation difficulty, and can solve the problems of difficulty in rural electricity use and poor power quality.

[0006] The purpose of the present invention is also to provide a dispatch optimization method for rural "wind, solar, storage and biogas" multi-energy complementarity, which can minimize the cost of power generation, increase the utilization rate of clean energy, meet rural electricity demand and reduce environmental pollution. In addition, the multi-energy complementary power supply system also cooperates with the large power grid, and sells surplus electricity to the large power grid on the premise of meeting the load demand, ensuring the rational use of resources.

[0007] A rural "wind, solar, storage and biogas" multi-energy complementary power supply system of the present invention comprises: a power generation unit for providing energy, an energy storage unit for storing energy, a load unit for consuming energy, a battery management module, an energy management system and a backup power supply;

[0008] Wherein, the power generation unit includes a wind power generation system, a photovoltaic power generation system and a biogas power generation system;

[0009] The biogas power generation system includes a biogas fermentation link, a biogas purification and utilization link, a composting link and a gas-heat conversion link. The biogas fermentation link is provided with an anaerobic fermentation tank, a discharge buffer tank and a solid-liquid separator. The biogas purification and utilization link is provided with a biogas blower, a dry desulfurization tank, a dryer, a filter and a biogas generator set. The composting link is provided with an integrated composting machine. The gas-heat conversion link is provided with a biogas furnace.

[0010] The energy storage unit includes electric energy storage and gas energy storage, the electric energy storage includes a battery pack, and the gas energy storage includes a biogas tank;

[0011] The load units include rural electricity users;

[0012] The energy management system is connected to the power generation unit, energy storage unit, battery management module, load unit and backup power supply, uses a chip processor integrated with the management system, and is connected to a touch screen to observe and manage power generation energy data in real time. Real-time monitoring of the power generation unit, energy storage unit and load unit;

[0013] The backup power source includes a large public power grid.

[0014] The output power of the wind power generation system of the present invention mainly depends on the local wind speed. The output power of the wind turbine is expressed as:

[0015]

[0016] Where: P WT (t) is the output of the fan system at time t; P r is the rated power of the wind turbine; v(t) is the real-time wind speed; v i is the cut-in wind speed of the wind turbine; v r is the rated wind speed; v o To cut out wind speed.

[0017] The output power of the photovoltaic power generation system of the present invention mainly depends on the local light intensity and the surface temperature of the photovoltaic panel. The output power of the solar panel is expressed as:

[0018]

[0019] Where: P PV (t) is the output of the photovoltaic system at time t; P STC is the rated output power of the photovoltaic panel under standard conditions; L WC (t) is the light intensity under working conditions; L STC is the light intensity under standard conditions; k is the relevant temperature coefficient; T WC (t) is the surface temperature of the photovoltaic panel under working conditions at time t; T STCis the surface temperature of the photovoltaic panel under standard conditions.

[0020] The surface temperature of the photovoltaic panel is T WC (t) It can be calculated using the ambient temperature, light intensity and real-time wind speed under working conditions, namely:

[0021]

[0022] Where: T e is the ambient temperature under working conditions; v(t) is the real-time wind speed at time t; c1, c2, and c3 are constants.

[0023] The output power of the biogas power generation system of the present invention mainly depends on the pressure and biogas consumption. The output power of biogas power generation is expressed as:

[0024]

[0025] Where: P G (t) is the output of the biogas power generation system at time t; G P is the biogas pressure; G V (t) is the real-time consumption of biogas; b1 is the constant term coefficient, b2 and b3 are the linear term coefficients of biogas power generation intensity and biogas consumption respectively; b4 is a constant coefficient.

[0026] The power generation process of the biogas power generation system includes six stages:

[0027] Phase 1: Feces and kitchen waste are collected from various parts of the countryside on a regular basis every day, pre-treated, mixed evenly, and then transported to the anaerobic fermentation tank by the material conveying system;

[0028] The second stage: the mixed materials produce biogas through the action of microorganisms in the anaerobic fermentation tank. After 30-35 days of retention, the materials flow into the discharge buffer tank through the discharge port for temporary storage. The materials in the temporary storage tank are sent to the solid-liquid separation system, the solid phase materials are sent to the composting system for composting, and the liquid phase enters the biogas tank for temporary storage before being sent out to the field.

[0029] The third stage: the biogas generated in the previous stage is pressurized by a biogas fan, and then sent to the dry desulfurization process for desulfurization to reduce the hydrogen sulfide content in the gas. After that, it is dehydrated by a dryer and filtered by a filter to remove dust, and then sent to the biogas power generation system for power generation;

[0030] The fourth stage: the treated biogas is sent to the biogas generator set, where the biogas is fully burned in the internal combustion engine, driving the generator to generate electricity. The generator room is equipped with a combustible gas alarm and an explosion-proof exhaust fan to improve the safety of the system.

[0031] The fifth stage: the solid waste generated in the process of producing biogas is mixed with straw, and its moisture content is adjusted to about 60% before being sent to the composting machine for composting. After 7 days of high-temperature maturation, it is sent to the stockpile. The organic fertilizer produced is used for fertilizing the surrounding farmland.

[0032] Stage 6: Under the premise of meeting the load power consumption and insufficient gas storage capacity of the biogas tank, the excess biogas is transported to the biogas furnace for combustion, and the heat generated by the combustion is sent back to the anaerobic fermentation tank to control the fermentation temperature and increase the biogas production.

[0033] The relationship between the biogas yield and the fermentation temperature of the present invention can be expressed as:

[0034] f t bio =m(T out -T o ) 2 +n

[0035] Where: f t bio is the gas production of the biogas digester at time t; m is the fermentation temperature coefficient; T out and T o is the temperature after heating and the optimal fermentation temperature; n is the gas production at the optimal temperature.

[0036] The dispatch optimization method of the rural "wind, solar, storage and biogas" multi-energy complementary power supply system of the present invention comprises:

[0037] Obtain basic information of the multi-energy complementary power supply system, and establish a dispatch optimization model of the multi-energy complementary power supply system based on the basic information;

[0038] Obtaining the dispatch optimization model configuration data of the multi-energy complementary power supply system;

[0039] According to the configuration data, improve the dispatch optimization model parameters of the multi-energy complementary power supply system, obtain the configuration plan, and perform simulation operation according to the configuration plan to optimize the power dispatch strategy of the multi-energy complementary power supply system;

[0040] The configuration data includes: wind / solar / storage / biogas output parameters, load size, simulation duration, and scheduling cycle.

[0041] The dispatch optimization model of the multi-energy complementary power supply system is constructed and improved according to the objective function and constraint conditions, and the configuration data of the multi-energy complementary power supply system is determined by adopting the minimum daily operating cost and the minimum amount of unused clean energy as the goals.

[0042] The objective function of the dispatch optimization model of the multi-energy complementary power supply system of the present invention is as follows:

[0043] 1. The objective function is to minimize the daily operating cost and the amount of unused clean energy. Its mathematical expression is:

[0044] F=min(F1,F2)

[0045] Where: F is the optimization target of the objective function, which contains two optimization sub-targets F1 and F2. F1 represents the minimum daily operating cost of the multi-energy complementary power supply system, and F2 represents the minimum unused amount of clean energy in the multi-energy complementary power supply system.

[0046] 2. In the objective function, the mathematical expression of the optimization sub-objective F1 is:

[0047]

[0048] Where: f g is the total cost of electricity purchased from the power grid within 24 hours; s is the total profit cost of selling electricity to the grid within 24 hours; bat is the dispatching cost of the battery group in the tth period; f ΔG is the gas abandonment cost of biogas power generation system; ΔPV is the cost of photovoltaic abandonment; f ΔWT is the wind abandonment cost of the wind turbine; its calculation formulas are:

[0049]

[0050] f ΔG =c G ΔP G Δt

[0051] f ΔPV =c PV ΔP PV Δt

[0052] f ΔWT =c WT ΔP WT Δt

[0053] Where: c(t) and d(t) are the purchase price and sales price of electricity at time t respectively; P in (t), P out (t) are the power purchased and sold at time t; c bat is the unit dispatching cost of the energy storage system; η c , η d are charge and discharge efficiency respectively; P c (t), P d (t) are the charging and discharging power of the battery at time t; c G 、c PV 、c WTare the unit abandoned gas, abandoned light and abandoned wind costs of biogas power generation, photovoltaic power generation and wind turbine respectively; ΔP G , ΔP PV , ΔP WT They are the power reduction of biogas power generation system, photovoltaic system and wind turbine system in the multi-energy complementary power supply system;

[0054] 3. In the objective function, the mathematical expression of the optimization sub-objective F2 is:

[0055]

[0056] Where: P G , P PV , P WT are the total power generation of the biogas power generation system, photovoltaic system, and wind turbine system; ΔP G , ΔP PV , ΔP WT They are respectively the power reduction of biogas power generation system, photovoltaic system and wind turbine system in the multi-energy complementary power supply system.

[0057] The constraints of the dispatch optimization model of the multi-energy complementary power supply system described in the present invention are as follows:

[0058] 1. Real-time monitoring of power generation units, energy storage units and load units, determining the power generation of the power generation unit, analyzing the charge state of the energy storage unit and the remaining capacity of the biogas tank, and updating the power demand of the load unit in real time;

[0059] 2. Determine the power balance constraint conditions, that is, to ensure that the output of the wind power generation system, photovoltaic power generation system, biogas power generation system, electric energy storage output and the sum of the system power shortage are balanced with the sum of the user's power demand and standby power. The formula is expressed as:

[0060] P WT (t)+P PV (t)+P G (t)+P bat (t)+P grid (t) = P L (t)+P exc (t);

[0061] Where: P WT (t) is the output of the fan system at time t; P PV (t) is the output of the photovoltaic system at time t; P G (t) is the output of the biogas power generation system at time t; P bat (t) is the real-time output of the electric energy storage at time t; P grid (t) is the input power from the large power grid at time t; P L(t) is the actual load power at time t; P exc (t) is the reserve power at time t, including the battery charge and the power delivered to the large power grid;

[0062] 3. Determine the gas balance constraint condition, that is, to ensure that the sum of the biogas digester output and the gas discharge of the biogas tank is equal to the sum of the gas consumption of the biogas power generation system, the gas storage capacity of the biogas tank and the gas consumption of the biogas furnace. The formula is expressed as:

[0063] f t bio +F t QS,dch =F t CHP +F t QS,ch +F t AB

[0064] Where: f t bio is the gas production of the biogas digester at time t; F t QS,dch F is the amount of gas released from the biogas tank; t CHP F is the gas consumption of biogas power generation system; t QS,ch F is the gas storage capacity of the biogas tank; t AB The gas consumption of the biogas stove;

[0065] 4. Determine the battery capacity, output, and power constraints as follows:

[0066] S SOCmin ≤S SOC (t)≤S SOCmax

[0067]

[0068] B c (t)+B d (t)≤1

[0069]

[0070] S SOC (T) = S SOC (0)

[0071] Where: S SOC (t) is the state of charge of the battery at time t; S SOCmax , S SOCmin are the upper and lower limits of the state of charge respectively; P c (t) is the charging power of the battery at time t; P d(t) is the discharge power of the battery at time t; P c max , are the maximum power limits of battery charging and discharging; B c (t), B d (t) are the charge and discharge flags at time t; Δt is the time interval; η c , η d are charging and discharging efficiency respectively; T is the optimized scheduling period;

[0072] 5. Determine the constraints of abandoned gas, abandoned solar power and abandoned wind volume respectively:

[0073]

[0074] Where: P G , P PV , P WT are the total power generation of the biogas power generation system, photovoltaic system, and wind turbine system; ΔP G , ΔP PV , ΔP WT They are respectively the power reduction of biogas power generation system, photovoltaic system and wind turbine system in the multi-energy complementary power supply system.

[0075] The acquisition configuration scheme of the present invention specifically includes:

[0076] S1 randomly initializes the particle swarm, determines the initial output values ​​of photovoltaic, wind turbine, biogas power generation system and energy storage in the multi-energy complementary power supply system, and generates the position and speed of the initial particles according to the initial values. Each particle represents a possible energy configuration scheme.

[0077] S2 evaluates the function fitness value of each particle;

[0078] S3 updates the individual optimal value and the global optimal value;

[0079] S4 updates the velocity and position of the particle;

[0080] S5 determines whether the convergence criterion is met. If not, it returns to S2; if so, it outputs the optimal result, which is the optimal scheduling plan for the rural "wind, solar, storage and biogas" multi-energy complementary power supply system.

[0081] The present invention uses an algorithm to calculate the real-time output of photovoltaic, wind turbine and other systems, and then configures the parameters to the simulation system for simulation. The two work together to adjust the output in real time and finally obtain the optimal scheduling plan.

[0082] The present invention provides a rural "wind, light, storage and biogas" multi-energy complementary power supply system and scheduling optimization method, wherein the energy management system connects the power generation unit, the energy storage unit, the load unit and the backup power supply. The parameters in the scheduling optimization model are improved according to the constraints and the objective function. The configuration scheme is an optimization algorithm. The optimal scheduling strategy can be obtained by simulating the scheduling optimization model using this algorithm. In this way, the specific conditions of the rural areas are combined to make full use of the resources in the rural areas. The biogas power generation system, the wind power generation system and the photovoltaic power generation system are used to continuously generate electricity, taking into account the stability, reliability and economy of the power supply system, and improving the utilization efficiency of rural resources. The power generation cost can be minimized, the utilization rate of clean energy can be increased, and the rural electricity demand can be met while reducing environmental pollution. In addition, the multi-energy complementary power supply system also cooperates with the large power grid. On the premise of meeting the load demand, the surplus electric energy is sold to the large power grid to ensure the rational use of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative work.

[0084] Figure 1 It is a structural schematic diagram of a rural "wind, solar, storage and biogas" multi-energy complementary power supply system proposed in an embodiment of the present invention;

[0085] Figure 2 It is a functional block diagram of a battery management system of a rural "wind, solar, storage and biogas" multi-energy complementary power supply system proposed in an embodiment of the present invention;

[0086] Figure 3 It is a schematic diagram of the energy distribution process of the rural "wind, solar, storage and biogas" multi-energy complementary power supply system proposed in an embodiment of the present invention;

[0087] Figure 4 It is an algorithm flow chart of the scheduling optimization method of the rural "wind, solar, storage and biogas" multi-energy complementary power supply system proposed in an embodiment of the present invention. DETAILED DESCRIPTION

[0088] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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. 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.

[0089] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the various features in the following embodiments can be combined with each other.

[0090] Figure 1 A schematic structural diagram of a rural "wind, solar, storage and biogas" multi-energy complementary power supply system provided in an embodiment of the present invention, the system includes: a wind power generation system, a photovoltaic power generation system and a biogas power generation system for providing electrical energy, an energy storage system for storing electrical energy, electricity users for consuming energy, a battery management system, an energy management system and a public large power grid.

[0091] The output power of the wind power generation system mainly depends on the local wind speed. The output power of the wind turbine is expressed as:

[0092] Where: P WT (t) is the output of the fan system at time t; P r is the rated power of the wind turbine; v(t) is the real-time wind speed; v i is the cut-in wind speed of the wind turbine; v r is the rated wind speed; v o To cut out wind speed.

[0093] The present invention adopts a wind power generator set with a rated power of 20kW.

[0094] The output power of the photovoltaic power generation system mainly depends on the local light intensity and the surface temperature of the photovoltaic panel. The output power of the solar panel is expressed as:

[0095]

[0096] Where: P PV (t) is the output of the photovoltaic system at time t; P STC is the rated output power of the photovoltaic panel under standard conditions; L WC (t) is the light intensity under working conditions; L STC is the light intensity under standard conditions; k is the relevant temperature coefficient; T WC (t) is the surface temperature of the photovoltaic panel under working conditions at time t; T STC is the surface temperature of the photovoltaic panel under standard conditions.

[0097] The surface temperature of the photovoltaic panel is T WC (t) It can be calculated using the ambient temperature, light intensity and real-time wind speed under working conditions, namely:

[0098]

[0099] Where: Te is the ambient temperature under working conditions; v(t) is the real-time wind speed at time t; c1, c2, and c3 are constants.

[0100] The present invention adopts a photovoltaic power generation group with a rated power of 165kW.

[0101] The output power of the biogas power generation system mainly depends on the pressure and biogas consumption. The output power of biogas power generation is expressed as:

[0102]

[0103] Where: P G (t) is the output of the biogas power generation system at time t; G P is the biogas pressure; G V (t) is the real-time consumption of biogas; b1 is the constant term coefficient, b2 and b3 are the linear term coefficients of biogas power generation intensity and biogas consumption respectively; b4 is a constant coefficient.

[0104] The present invention adopts a biogas generator set with a rated power of 30kW.

[0105] Compared with wind and solar energy, the biogas power generation system has certain storage characteristics. When sufficient biogas is produced, it can be stored in biogas tanks and taken out when needed, which is more flexible.

[0106] The biogas power generation system includes a biogas fermentation link, a biogas purification and utilization link, a composting link and a gas-heat conversion link. The present invention proposes that an anaerobic fermentation tank, a discharge buffer tank and a solid-liquid separator are provided in the biogas fermentation link, a biogas blower, a dry desulfurization tank, a dryer, a filter and a biogas generator set are provided in the biogas purification and utilization link, an integrated composting machine is provided in the composting link, and a biogas furnace is provided in the gas-heat conversion link;

[0107] The power generation process of the biogas power generation system of the present invention includes six stages:

[0108] Phase 1: Feces and kitchen waste are collected from various parts of the countryside on a regular basis every day, pre-treated, mixed evenly, and then transported to the anaerobic fermentation tank by the material conveying system;

[0109] The second stage: the mixed materials produce biogas through the action of microorganisms in the anaerobic fermentation tank. After 30-35 days of retention, the materials flow into the discharge buffer tank through the discharge port for temporary storage. The materials in the temporary storage tank are sent to the solid-liquid separation system, the solid phase materials are sent to the composting system for composting, and the liquid phase enters the biogas tank for temporary storage before being sent out to the field.

[0110] The third stage: the biogas generated in the previous stage is pressurized by a biogas fan, and then sent to the dry desulfurization process for desulfurization to reduce the hydrogen sulfide content in the gas. After that, it is dehydrated by a dryer and filtered by a filter to remove dust, and then sent to the biogas power generation system for power generation;

[0111] The fourth stage: the treated biogas is sent to the biogas generator set, where the biogas is fully burned in the internal combustion engine, driving the generator to generate electricity. The generator room is equipped with a combustible gas alarm and an explosion-proof exhaust fan to improve the safety of the system.

[0112] The fifth stage: the solid waste generated in the process of producing biogas is mixed with straw, and its moisture content is adjusted to about 60% before being sent to the composting machine for composting. After 7 days of high-temperature maturation, it is sent to the stockpile. The organic fertilizer produced is used for fertilizing the surrounding farmland.

[0113] Stage 6: Under the premise of meeting the load power consumption and insufficient gas storage capacity of the biogas tank, the excess biogas is transported to the biogas furnace for combustion, and the heat generated by the combustion is sent back to the anaerobic fermentation tank to control the fermentation temperature and increase the biogas production.

[0114] The relationship between biogas production and fermentation temperature can be expressed as:

[0115] f t bio =m(T out -T o ) 2 +n

[0116] Where: f t bio is the gas production of the biogas digester at time t; m is the fermentation temperature coefficient; T out and T o is the temperature after heating and the optimal fermentation temperature; n is the gas production at the optimal temperature.

[0117] The energy management system uses a chip processor integrated with a management system and is connected to a touch screen to observe and manage power generation energy data in real time. It monitors the power generation unit, energy storage unit and load unit in real time.

[0118] Figure 2 As shown, the battery pack is also connected to an intelligent battery management module (BMS), which uses the state selection module, current detection module, capacity control module and data management module to protect the battery pack from charge and discharge, and can also monitor the state of the battery pack. The energy management system is preset with a charge and discharge control module, which controls the charge and discharge of the battery pack by reading the data of the intelligent battery management module.

[0119] The control strategy of the battery pack uses the voltage at the energy storage end as the main reference parameter to control the battery pack to select one of the charging mode, idle mode, and discharge mode. During the process, the status of the energy storage module is monitored at any time, and the charging voltage and current are adjusted in real time. When the battery pack power reaches the set upper limit, the intelligent battery management module stops charging according to the feedback signal received; if the power supply load increases at a certain moment and the power supply is insufficient, the energy management system can control the battery pack to discharge, make up for the power difference, and ensure the stability of the power supply system.

[0120] Combination Figure 3 , which shows in detail the flow direction of electricity and biogas in the system. Photovoltaic, wind turbines, biogas power generation systems, batteries and large power grids complement each other to meet the load needs of users. The biogas produced by the biogas digester in the biogas power generation system is provided to the power generation system on the one hand, and the surplus biogas is transmitted to the biogas tank for gas storage and to the biogas furnace for combustion to generate heat which is fed back to the biogas digester to control the gas production temperature of the biogas digester and increase the biogas production.

[0121] In another aspect of the embodiment of the present invention, a scheduling optimization method for the rural "wind, solar, storage and biogas" multi-energy complementary power supply system in the above embodiment is also provided, the method comprising:

[0122] The basic information of the rural "wind, solar, storage and biogas" multi-energy complementary power supply system is obtained, and the dispatch optimization model of the multi-energy complementary power supply system is established based on the basic information. The minimum daily operating cost and the minimum unused amount of clean energy are used as the objective function, and the energy flow is reasonably allocated according to the constraints set by the system, so that the power dispatch of the system can take into account both economy and energy utilization efficiency, and ensure the rational use of resources.

[0123] The specific content of the objective function is as follows:

[0124] 1. The objective function is to minimize the daily operating cost and the amount of unused clean energy. Its mathematical expression is:

[0125] F=min(F1,F2)

[0126] Where: F is the optimization target of the objective function, which contains two optimization sub-targets F1 and F2. F1 represents the minimum daily operating cost of the multi-energy complementary power supply system, and F2 represents the minimum unused amount of clean energy in the multi-energy complementary power supply system.

[0127] 2. In the objective function, the mathematical expression of the optimization sub-objective F1 is:

[0128]

[0129] Where: f g is the total cost of electricity purchased from the power grid within 24 hours; sis the total profit cost of selling electricity to the grid within 24 hours; bat is the dispatching cost of the battery group in the tth period; f ΔG is the gas abandonment cost of biogas power generation system; ΔPV is the cost of photovoltaic abandonment; f ΔWT is the wind abandonment cost of the wind turbine; its calculation formulas are:

[0130]

[0131] f ΔG =c G ΔP G Δt

[0132] f ΔPV =c PV ΔP PV Δt

[0133] f ΔWT =c WT ΔP WT Δt

[0134] Where: c(t) and d(t) are the purchase price and sales price of electricity at time t respectively; P in (t), P out (t) are the power purchased and sold at time t; c bat is the unit dispatching cost of the energy storage system; η c , η d are the charge and discharge efficiency respectively; P c (t), P d (t) are the charging and discharging power of the battery at time t; c G 、c PV 、c WT are the unit abandoned gas, abandoned light and abandoned wind costs of biogas power generation, photovoltaic power generation and wind turbine respectively; ΔP G , ΔP PV , ΔP WT They are the power reduction of biogas power generation system, photovoltaic system and wind turbine system in the multi-energy complementary power supply system;

[0135] 3. In the objective function, the mathematical expression of the optimization sub-objective F2 is:

[0136]

[0137] Where: P G , P PV , P WT are the total power generation of the biogas power generation system, photovoltaic system, and wind turbine system; ΔP G , ΔP PV , ΔP WTThey are respectively the power reduction of biogas power generation system, photovoltaic system and wind turbine system in the multi-energy complementary power supply system.

[0138] The specific contents of the constraints are as follows:

[0139] 1. Real-time monitoring of power generation units, energy storage units and load units, determining the power generation of the power generation unit, analyzing the charge state of the energy storage unit and the remaining capacity of the biogas tank, and updating the power demand of the load unit in real time;

[0140] 2. Determine the power balance constraint conditions, that is, to ensure that the output of the wind power generation system, photovoltaic power generation system, biogas power generation system, electric energy storage output and the sum of the system power shortage are balanced with the sum of the user's power demand and standby power. The formula is expressed as:

[0141] P WT (t)+P PV (t)+P G (t)+P bat (t)+P grid (t) = P L (t)+P exc (t);

[0142] Where: P WT (t) is the output of the fan system at time t; P PV (t) is the output of the photovoltaic system at time t; P G (t) is the output of the biogas power generation system at time t; P bat (t) is the real-time output of the electric energy storage at time t; P grid (t) is the input power from the large power grid at time t; P L (t) is the actual load power at time t; P exc (t) is the reserve power at time t, including the battery charge and the power delivered to the large power grid;

[0143] 3. Determine the gas balance constraint condition, that is, to ensure that the sum of the biogas digester output and the gas discharge of the biogas tank is equal to the sum of the gas consumption of the biogas power generation system, the gas storage capacity of the biogas tank and the gas consumption of the biogas furnace. The formula is expressed as:

[0144] f t bio +F t QS,dch =F t CHP +F t QS,ch +F t AB

[0145] Where: f t biois the gas production of the biogas digester at time t; F t QS,dch F is the amount of gas released from the biogas tank; t CHP F is the gas consumption of biogas power generation system; t QS,ch F is the gas storage capacity of the biogas tank; t AB The gas consumption of the biogas stove;

[0146] 4. Determine the battery capacity, output, and power constraints as follows:

[0147] S SOCmin ≤S SOC (t)≤S SOCmax 0≤P c (t)≤P c max B c (t)

[0148]

[0149] B c (t)+B d (t)≤1

[0150]

[0151] S SOC (T) = S SOC (0)

[0152] Where: S SOC (t) is the state of charge of the battery at time t; S SOCmax , S SOCmin are the upper and lower limits of the state of charge respectively; P c (t) is the charging power of the battery at time t; P d (t) is the discharge power of the battery at time t; are the maximum power limits of battery charging and discharging; B c (t), B d (t) are the charge and discharge flags at time t; Δt is the time interval; η c , η d are charging and discharging efficiency respectively; T is the optimized scheduling period;

[0153] 5. Determine the constraints of abandoned gas, abandoned solar power and abandoned wind volume respectively:

[0154]

[0155] Where: P G , P PV , PWT are the total power generation of the biogas power generation system, photovoltaic system, and wind turbine system; ΔP G , ΔP PV , ΔP WT They are respectively the power reduction of biogas power generation system, photovoltaic system and wind turbine system in the multi-energy complementary power supply system.

[0156] The dispatch optimization model of the rural "wind, solar, storage and biomass" multi-energy complementary power supply system is solved by using the particle swarm optimization algorithm, such as Figure 4 As shown, the specific solution steps include:

[0157] Step 1: Randomly initialize the particle swarm, determine the initial output values ​​of photovoltaic, wind turbine, biogas power generation system and energy storage in the multi-energy complementary power supply system, generate the position and speed of the initial particles according to the initial values, and each particle represents a possible energy configuration scheme;

[0158] Step 2, evaluate the function fitness value of each particle;

[0159] Step 3, update the individual optimal value and the global optimal value;

[0160] Step 4, update the velocity and position of the particle;

[0161] Step 5, determine whether the convergence criterion is met, if not, return to step 2; if yes, output the optimal result, which is the optimal scheduling plan for the rural "wind, solar, storage and biogas" multi-energy complementary power supply system.

[0162] The biggest difference between the multi-energy complementary power supply system and dispatch optimization method of the present invention and the prior art is that it integrates wind power generation system, photovoltaic power generation system, biogas power generation system and energy storage system, overcomes the problems of poor power output stability and insufficient supply caused by the operation of a single power generation device, and is uniformly managed and maintained by the control system. Further establishing a dispatch optimization model for a multi-energy complementary power supply system enables the system's power dispatch to take into account both economic efficiency and energy efficiency, ensure the rational use of resources, reduce environmental pollution, and ensure the reliability and stability of the rural power supply system.

Claims

1. A rural "wind, solar, storage and biogas" multi-energy complementary power supply system, characterized in that: The power supply system includes: a power generation unit for providing energy, an energy storage unit for storing energy, a load unit for consuming energy, a battery management module, an energy management system and a backup power supply; Wherein, the power generation unit includes a wind power generation system, a photovoltaic power generation system and a biogas power generation system; The energy storage unit includes electric energy storage and gas energy storage, the electric energy storage includes a battery pack, and the gas energy storage includes a biogas tank; The load units include rural electricity users; The energy management system is connected to the power generation unit, energy storage unit, battery management module, load unit and backup power supply, uses a chip processor integrated with a management system, and is externally connected to a touch screen to observe and manage power generation energy data in real time; and performs real-time monitoring of the power generation unit, energy storage unit and load unit; The backup power source includes a large public power grid.

2. The rural "wind, solar, storage and biogas" multi-energy complementary power supply system as claimed in claim 1 is characterized in that: The output power of the wind power generation system depends on the local wind speed. The output power of the wind turbine is expressed as: Where: P WT (t) is the output of the fan system at time t; P r is the rated power of the wind turbine; v(t) is the real-time wind speed; v i is the cut-in wind speed of the wind turbine; v r is the rated wind speed; v o To cut out wind speed.

3. The rural "wind, solar, storage and biogas" multi-energy complementary power supply system as claimed in claim 1 is characterized in that: The output power of the photovoltaic power generation system depends on the local light intensity and the surface temperature of the photovoltaic panel. The output power of the solar panel is expressed as: Where: P PV (t) is the output of the photovoltaic system at time t; P STC is the rated output power of the photovoltaic panel under standard conditions; L WC (t) is the light intensity under working conditions; L STC is the light intensity under standard conditions; k is the relevant temperature coefficient; T WC (t) is the surface temperature of the photovoltaic panel under working conditions at time t; T STC is the surface temperature of the photovoltaic panel under standard conditions.

4. The rural "wind, solar, storage and biogas" multi-energy complementary power supply system as claimed in claim 3 is characterized in that: The surface temperature of the photovoltaic panel is T WC (t) Calculated using ambient temperature, light intensity and real-time wind speed under working conditions, namely: Where: T e is the ambient temperature under working conditions; v(t) is the real-time wind speed at time t; c1, c2, and c3 are constants.

5. The rural "wind, solar, storage and biogas" multi-energy complementary power supply system as claimed in claim 1 is characterized in that: The output power of the biogas power generation system depends on the pressure and biogas consumption. The output power of biogas power generation is expressed as: Where: P G (t) is the output of the biogas power generation system at time t; G P is the biogas pressure; G V (t) is the real-time consumption of biogas; b1 is the constant term coefficient, b2 and b3 are the linear term coefficients of biogas power generation intensity and biogas consumption respectively; b4 is a constant coefficient.

6. The rural "wind, solar, storage and biogas" multi-energy complementary power supply system as claimed in claim 5 is characterized in that: The relationship between the biogas production and the fermentation temperature is expressed as: Where: is the gas production of the biogas digester at time t; m is the fermentation temperature coefficient; T out and T o is the temperature after heating and the optimal fermentation temperature; n is the gas production at the optimal temperature.

7. A dispatch optimization method for a rural "wind, solar, storage and biogas" multi-energy complementary power supply system based on any one of claims 1 to 6, characterized in that include: Obtain basic information of the multi-energy complementary power supply system, and establish a dispatch optimization model of the multi-energy complementary power supply system based on the basic information; Obtaining the dispatch optimization model configuration data of the multi-energy complementary power supply system; According to the configuration data, improve the dispatch optimization model parameters of the multi-energy complementary power supply system, obtain the configuration plan, and perform simulation operation according to the configuration plan to optimize the power dispatch strategy of the multi-energy complementary power supply system; The scheduling optimization model of the multi-energy complementary power supply system is constructed and improved according to the objective function and constraint conditions, and the configuration data of the multi-energy complementary power supply system is determined by taking the minimum daily operating cost and the minimum amount of unused clean energy as the goals.

8. The scheduling optimization method according to claim 7, characterized in that The configuration data includes: wind / solar / storage / biogas output parameters, load size, simulation duration, and scheduling cycle.

9. The scheduling optimization method according to claim 7, characterized in that The objective function of the dispatch optimization model of the multi-energy complementary power supply system is as follows:

1. The objective function is to minimize the daily operating cost and the amount of unused clean energy. Its mathematical expression is: F=min(F1,F2) Where: F is the optimization target of the objective function, which contains two optimization sub-targets F1 and F2. F1 represents the minimum daily operating cost of the multi-energy complementary power supply system, and F2 represents the minimum unused amount of clean energy in the multi-energy complementary power supply system.

2. In the objective function, the mathematical expression of the optimization sub-objective F1 is: Where: f g is the total cost of electricity purchased from the power grid within 24 hours; s is the total profit cost of selling electricity to the grid within 24 hours; bat is the dispatching cost of the battery group in the tth period; f ΔG is the gas abandonment cost of biogas power generation system; ΔPV is the cost of photovoltaic abandonment; f ΔWT is the wind abandonment cost of the wind turbine; its calculation formulas are: f ΔG =c G ΔP G Δt f ΔPV =c PV ΔP PV Δt f ΔWT =c WT ΔP Wr Δt Where: c(t) and d(t) are the purchase price and sales price of electricity at time t respectively; P in (t), P out (t) are the power purchased and sold at time t; c bat is the unit dispatch cost of the energy storage system; η c , η d are the charge and discharge efficiency respectively; P c (t), P d (t) are the charging and discharging power of the battery at time t; c G 、c PV 、c WT are the unit abandoned gas, abandoned light and abandoned wind costs of biogas power generation, photovoltaic power generation and wind turbine respectively; ΔP G , ΔP PV , ΔP WT They are the power reduction of biogas power generation system, photovoltaic system and wind turbine system in the multi-energy complementary power supply system; 3. In the objective function, the mathematical expression of the optimization sub-objective F2 is: Where: P G , P PV , P WT are the total power generation of the biogas power generation system, photovoltaic system, and wind turbine system; ΔP G , ΔP PV , ΔP WT They are respectively the power reduction of biogas power generation system, photovoltaic system and wind turbine system in the multi-energy complementary power supply system.

10. The scheduling optimization method according to claim 7, characterized in that: The constraints of the dispatch optimization model of the multi-energy complementary power supply system are as follows:

1. Real-time monitoring of power generation units, energy storage units and load units, determining the power generation of the power generation unit, analyzing the charge state of the energy storage unit and the remaining capacity of the biogas tank, and updating the power demand of the load unit in real time; 2. Determine the power balance constraint conditions, that is, to ensure that the output of the wind power generation system, photovoltaic power generation system, biogas power generation system, electric energy storage output and the sum of the system power shortage are balanced with the sum of the user's power demand and standby power. The formula is expressed as: P WT (t)+P PV (t)+P G (t)+P bat (t)+p grid (t)=P L (t)+P exc (t); Where: P WT (t) is the output of the fan system at time t; P PV (t) is the output of the photovoltaic system at time t; P G (t) is the output of the biogas power generation system at time t; P bat (t) is the real-time output of the electric energy storage at time t; P grid (t) is the input power from the large power grid at time t; P L (t) is the actual load power at time t; P exc (t) is the reserve power at time t, including the battery charge and the power delivered to the large power grid; 3. Determine the gas balance constraint condition, that is, to ensure that the sum of the biogas digester output and the gas discharge of the biogas tank is equal to the sum of the gas consumption of the biogas power generation system, the gas storage capacity of the biogas tank and the gas consumption of the biogas furnace. The formula is expressed as: Where: f t bio is the gas production of the biogas digester at time t; F t QS，dch The amount of gas released from the biogas tank; F is the gas consumption of biogas power generation system; t QS，ch The gas storage capacity of the biogas tank; The gas consumption of the biogas stove; 4. Determine the battery capacity, output, and power constraints as follows: S SOCmin ≤S SOC (t)≤S SOCmax B c (t)+B d (t)≤1 S SOC (T)=S SOC (0) Where: S SOC (t) is the state of charge of the battery at time t; S SOCmax , S SOCmin are the upper and lower limits of the state of charge respectively; P c (t) is the charging power of the battery at time t; P d (t) is the discharge power of the battery at time t; are the maximum power limits of battery charging and discharging; B c (t), B d (t) are the charge and discharge flags at time t; Δt is the time interval; η c , η d are charging and discharging efficiency respectively; T is the optimized scheduling period; 5. Determine the constraints of abandoned gas, abandoned solar power and abandoned wind volume respectively: Where: P G , P PV , P WT are the total power generation of the biogas power generation system, photovoltaic system, and wind turbine system; ΔP G , ΔP PV , ΔP WT They are respectively the power reduction of biogas power generation system, photovoltaic system and wind turbine system in the multi-energy complementary power supply system.

11. The scheduling optimization method according to claim 7, characterized in that The acquisition configuration scheme includes: S1 randomly initializes the particle swarm, determines the initial output values ​​of photovoltaic, wind turbine, biogas power generation system and energy storage in the multi-energy complementary power supply system, and generates the position and speed of the initial particles according to the initial values. Each particle represents a possible energy configuration scheme. S2 evaluates the function fitness value of each particle; S3 updates the individual optimal value and the global optimal value; S4 updates the velocity and position of the particle; S5 determines whether the convergence criterion is met. If not, it returns to S2; if so, it outputs the optimal result, which is the optimal scheduling plan for the rural "wind, solar, storage and biogas" multi-energy complementary power supply system.

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