A Coordinated Dispatch Method for Flexible Loads and Photovoltaics Based on Coal Mine Production Characteristics Constraints

Abstract

This invention discloses a method for coordinated scheduling of flexible loads and photovoltaic power generation based on coal mine production characteristics constraints. The method includes: establishing a flexible load model based on coal mine production characteristics constraints; constructing constraint relationships based on the flexible load model; constructing and solving the objective function for coordinated scheduling of flexible loads and photovoltaic power generation to obtain the day-ahead operating power curve of the flexible load; and performing coordinated scheduling of flexible loads and photovoltaic power generation at different times. This invention combines the scheduling space of coal mine flexible loads to improve the matching degree between photovoltaic power generation and coal mine source loads, achieving daytime source load curve alignment. Furthermore, by using peak-valley electricity pricing, it further adjusts the equipment operating status at different times, enabling peak-valley adjustment of coal mine loads, efficient photovoltaic absorption, and low-carbon coal mine production. This provides a theoretical basis and data support for the optimal low-carbon coupling of photovoltaic power generation and coal mine source loads in mining areas.

Description

Technical Field

[0001] This invention relates to an energy optimization scheduling method, specifically a flexible load and photovoltaic coordinated scheduling method based on coal mine production characteristics constraints, belonging to the field of low-carbon energy production technology. Background Technology

[0002] my country is rich in coal resources, and coal is one of the country's main energy sources. According to the 2021 Statistical Communiqué on National Economic and Social Development of my country, coal consumption accounts for 56% of total energy consumption. Coal mining involves multiple stages, including extraction, transportation, drainage, and ventilation. The industry is characterized by high energy consumption, high energy costs, and a strong dependence on fossil fuels. How to achieve energy-efficient and economical production in coal mines is a key concern within the industry.

[0003] Coal mining is a combination of energy use and production capacity. The mining process involves multiple energy demands, including electricity, heat, and cooling. On the one hand, coal mining consumes a large amount of energy. Mining, transportation, ventilation, drainage, and heating systems typically operate at a constant rate, leading to difficulties in matching energy supply and demand due to low daytime energy load. This results in low energy efficiency and significant energy waste. For example, in the same coal production shift, ventilation fans operate at a relatively constant power, often delivering more air than the actual required air volume plus the reserve air volume, resulting in unnecessary energy consumption. On the other hand, although the operation of drainage pumps, ventilation fans, and other energy conversion equipment generates associated energy sources such as coal mine water inrush, exhaust air, and equipment waste heat, which can be converted into valuable resources through technologies like power generation and heat pumps, the amount of associated energy is difficult to predict as mining extends underground and the geological environment changes. Therefore, the utilization of associated energy is not ideal.

[0004] Compared to the aforementioned traditional new energy sources in mining areas, photovoltaic power generation has become the preferred choice for many mining areas due to its pollution-free and carbon-free characteristics. However, photovoltaic power generation is affected by factors such as light intensity and temperature, resulting in significant randomness and fluctuations in output. This increases the difficulty of matching daytime source and load and makes it prone to curtailment. Consequently, the utilization effect of photovoltaic power generation in mining areas is not ideal. How to improve the matching degree between photovoltaic power generation in mining areas and coal mine source and load, reduce resource and energy waste, and achieve low-carbon and efficient operation of coal mines are urgent problems to be solved in the industry. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for coordinated scheduling of elastic load and photovoltaic power generation based on the constraints of coal mine production characteristics. This method can improve the matching degree between photovoltaic power generation in the mining area and coal mine source load, reduce resource and energy waste, and achieve low-carbon and efficient operation of coal mines. It can provide theoretical basis and data support for the optimal low-carbon coupling of photovoltaic power generation in the mining area and coal mine source load.

[0006] To achieve the above objectives, this method for coordinated scheduling of flexible loads and photovoltaic power based on coal mine production characteristics specifically includes the following steps:

[0007] Step 1. Based on the constraints of coal mine production characteristics, establish a flexible load model. The flexible load model includes a strong safety constraint flexible load model and a non-strong safety constraint flexible load model. The strong safety constraint flexible load model includes a mining and transportation link flexible load model, a ventilation flexible load model, and an underground drainage flexible load model. The non-strong safety constraint flexible load model includes a water source heat pump flexible load model and a wellhead insulation flexible load model.

[0008] Step 2. Based on the elastic load model, determine the known parameters and decision variables, and construct the constraint relationships;

[0009] ① The upper and lower limits of power consumption for flexible loads are expressed as follows:

[0010] 0≤P t ≤P max

[0011] In the formula: P t P represents the electrical power of the elastic load at time t, in kW. max The maximum operating electrical power of the flexible load is expressed in kW.

[0012] ② Elastic load ramping constraint

[0013] To prevent the flexible load from switching between a stopped and high-power operating state at adjacent operating times, the ramp-up power of the flexible load is limited. The ramp-up constraint of the flexible load is expressed as follows:

[0014] -η p P max ≤P t+1 -P t ≤η p P max

[0015] In the formula: η p The percentage of elastic load ramp rate, %; P t+1 Let be the electrical power of the elastic load at time t+1, in kW.

[0016] ③ The power balance constraints of the energy system are expressed as follows:

[0017] P grid,t +P gen,t =P load,t

[0018] H buy,t +H gen,t =H load,t

[0019] In the formula: Pgrid,t Let P be the purchased power at time t, in kW; gen,t P represents the power output of the system's built-in generator at time t, in kW. load,t Let t be the total electrical load power of all electrical equipment at time t, expressed in kW or H. buy,t The purchased heat power at time t is expressed in kW and H. gen,t The heating power of the system's built-in heating equipment at time t is expressed in kW and H. load,t Let t be the total heat load power demanded by all heat sources at time t, in kW;

[0020] Step 3. Construct the objective function for coordinated scheduling of flexible loads and photovoltaic power generation, and solve it to obtain the day-ahead operating power curve of the flexible loads, and carry out coordinated scheduling of flexible loads and photovoltaic power generation at different times;

[0021] The objective function for coordinated scheduling of flexible loads and photovoltaic power is expressed as follows:

[0022] Z = β grid P grid +β pv P pv +β gas GAS

[0023] In the formula: Z represents the total carbon emissions of the system, tCO2; β grid For the carbon emissions per unit of the power grid, tCO2 / kWh; β pv tCO2 / kWh represents the carbon emissions per unit of photovoltaic power generation; β gas Carbon emissions per unit of natural gas, tCO2 / MJ; P grid Total purchased electricity, kWh; P pv 1 represents the total photovoltaic power generation, in kWh; GAS represents the total calorific value of natural gas, in MJ.

[0024] Furthermore, in Step 1, the elastic load model for the mining and transportation process includes the elastic load model for the coal mining machine, the elastic load model for the belt conveyor, and the elastic load models for the underground and surface coal bunkers. Specifically:

[0025] ①The elastic load model of the coal mining machine is represented as follows:

[0026]

[0027]

[0028] In the formula: Let t be the operating power of the coal mining machine at time t, in kW; Let t be the traction speed of the coal mining machine at time t, in m / s; θ is a coefficient related to the structural parameters of the coal mining machine (according to standard ISO5048); This represents the maximum traction speed of the coal mining machine, in m / s;

[0029] ②The elastic load model of the belt conveyor is represented as follows:

[0030]

[0031]

[0032] 0≤v t ≤v max

[0033] In the formula: η is the average power of the belt conveyor in hour t, in kW; μ is a coefficient related to the structure of the belt conveyor (according to standard ISO 5048); η d η m Efficiency, in % for the electric motor and drive system, respectively; v represents the mass per unit length of the belt conveyor during time period t, in kg / m. t W represents the belt's transmission speed, in m / s. t v represents the conveying capacity of the belt conveyor in time period t, in tons per hour; max The maximum transmission speed of the belt is ____ m / s; This represents the upper limit of the mass per unit length that a belt conveyor can withstand, expressed in kg / m.

[0034] ③ The elastic load models for underground and surface coal bunkers are expressed as follows:

[0035] If the upper limit of coal bunker capacity is set at 90% and the lower limit at 20%, then...

[0036] C t+1 =C t +θ in,t -θ out,t

[0037] 0.2C N ≤C t ≤0.9C N

[0038] In the formula: θ in,t θ out,t These represent the amount of coal transported into and out of the coal bunker in hour t, in tons; C N C represents the capacity of the coal bunker, in tons. t Let t be the amount of coal stored in the coal bunker in hour t, in tons.

[0039] Furthermore, in Step 1, the ventilation flexible load model includes an air volume calculation model and a ventilation fan flexible load model, specifically:

[0040] ①The air volume calculation model is expressed as follows:

[0041] Q P,i =K×(∑Q C,i +∑Q J,i +∑Q D,i +∑Q H,i )

[0042] In the formula: Q P,i For total air volume, m 3 / h; K is the mine ventilation coefficient, with a value of 1.2; Q C,i The required air volume for the coal mining face, in m 3 / h;Q J,i The required air volume at the tunneling face, m 3 / h;Q D,i The required air volume (m) for an independent air supply chamber 3 / h;Q H,i For the required air volume in other tunnels, m 3 / h;

[0043] Q C =125k c ×q c

[0044] In the formula: 125 is the conversion factor; k c q is the gas emission imbalance coefficient at the coal mining face, with a value of 2.5; c The relative gas emission rate at the coal mining face, in m 3 / ton;

[0045] Q J =100k J ×q J

[0046] In the formula: 100 is the conversion factor; k J The gas outburst imbalance coefficient at the tunneling face is set to 2; q J The relative gas emission rate (m) at the tunneling face 3 / ton;

[0047] Q D =80N D

[0048] In the formula: 80 is the average air volume of a single chamber, in m³. 3 / h;N D The number of chambers;

[0049] Q H =133N H

[0050] In the formula: 133 is the conversion factor for gas emission in a single roadway; N H The number of lanes;

[0051] ②The elastic load model of the ventilation fan is expressed as follows:

[0052] P TF,t =f(Q) TF,t ,p TF ,η TF )

[0053] Q TF,t ≥Q P

[0054] In the formula: P TF,t Let Q be the operating power of the fan at time t, in kW; TF,t Let m be the air intake volume of the fan at time t. 3 / h;p TF The total air pressure of the fan is expressed in Pa; η TF For the operating efficiency of the ventilation fan, %.

[0055] Furthermore, in Step 1, the downhole drainage elastic load model includes the downhole drainage pump elastic load model and the downhole water tank elastic load model, specifically:

[0056] ①The elastic load model of the downhole drainage pump is represented as follows:

[0057] P X =f(κ,g,W) X ,h X ,η X )

[0058] 0≤W X ≤W X，max

[0059] In the formula: X represents the type of drainage pump; P X κ represents the operating power of type X water pump, in kW; κ represents the specific gravity of the medium, in kg / m³. 3 g is the acceleration due to gravity, taken as 9.8 N / kg; W X The operating flow rate (m) of type X water pump 3 / h;h X For type X water pumps, the head is in meters (m); η X The operating efficiency (%) of type X water pump; W X，max The maximum operating flow rate (m) of type X water pump 3 / h;

[0060] ②The elastic load model of the underground water tank is represented as follows:

[0061] The empty capacity of the water tank should be maintained at more than 50% of the total capacity, that is:

[0062] V EM ≥0.5V max

[0063] In the formula: V EM The empty capacity of the water tank is in meters. 3 V max The total capacity of the water tank is in meters. 3 .

[0064] Furthermore, in Step 1, the elastic load model of the water source heat pump is represented as follows:

[0065]

[0066] In the formula: P hepm,t The power consumed by the water source heat pump unit during time period t, in kW; H hepm,t The heating capacity of the water source heat pump unit during time period t is expressed in kW; COP is the coefficient of performance of the water source heat pump unit; H exch,t α is the heat absorbed by the water source heat pump unit from the heat source side during time period t, in kW; α is the specific heat capacity of the circulating working fluid, in J / (kg·℃); ο is the mass flow rate of the circulating working fluid, in kg / h; T in T out These are the inlet and outlet temperatures of the water source heat pump evaporator, respectively, in °C.

[0067] Furthermore, in Step 1, the wellhead insulation elastic load model is represented as follows:

[0068] H FD =f(Q) TF,ave ,ρ inair C ENT ,T mix ,T low )

[0069] H FD,t ≥H FD

[0070] In the formula: H FD The basic thermal power required for wellhead freeze protection, in kW; Q TF,ave The average air intake at the wellhead, in meters (m) 3 / s;ρ inair For air density, take the value as 1.28 kg / m³. 3 C ENT The specific heat capacity of air at constant pressure is taken as 1.01 kJ / (kg·℃); T mix T represents the temperature after the hot and cold air are mixed, in °C. low The lowest ambient temperature in winter, °C; H FD,t Let t be the thermal power required for wellhead freeze protection, in kW.

[0071] Furthermore, Step 3 utilizes the Gurobi solver for calculation and solution.

[0072] Compared with existing technologies, this method of coordinated scheduling of elastic load and photovoltaic power based on the constraints of coal mine production characteristics combines the scheduling space of elastic load in coal mines to improve the matching degree between photovoltaic power generation in the mining area and coal mine source load, achieve daytime source load curve alignment, and further adjust the equipment operating status at different times through peak and valley electricity pricing. This can realize peak and valley period adjustment of coal mine load, efficient consumption of photovoltaic power, and low-carbon production in coal mines. Simulation verification shows that although the energy purchase cost of coordinated scheduling operation increases by 2,300 yuan compared with constant state operation, CO2 emissions are reduced by 0.93887 tons. This provides a theoretical basis and data support for the optimal low-carbon coupling of photovoltaic power generation in mining areas and coal mine source load. Attached Figure Description

[0073] Figure 1 This is a flowchart of the present invention;

[0074] Figure 2 This is a diagram illustrating the coordinated scheduling results of flexible load and photovoltaic power generation in coal mines according to an embodiment of the present invention.

[0075] Figure 3 This is a diagram illustrating the carbon dioxide emissions from a coal mine according to an embodiment of the present invention. Detailed Implementation

[0076] Coal mine production characteristic constraints refer to the requirement that the load must meet both the safety constraints stipulated in coal mine safety regulations and its own operational constraints during normal operation.

[0077] Flexible loads refer to loads whose electrical (thermal) power demand has room for scheduling or can be started and stopped, while still meeting the constraints of coal mine production characteristics. Flexible loads are divided into two categories: loads with strong safety constraints and loads without strong safety constraints. Loads with strong safety constraints are those where the load itself or the production process it involves has mandatory safety requirements in the coal mine, including loads in the mining and transportation process, ventilation loads, and underground drainage loads. Loads without strong safety constraints are those where the load only needs to meet the operational requirements of the production process it involves, including water source heat pump loads and wellhead insulation loads.

[0078] Matching photovoltaic power generation in mining areas with coal mine power sources and loads means that, based on the constraints of coal mine production characteristics, the normal operation constraints of flexible loads, and the power balance constraints of the energy system, the strategy is to match the peak and valley periods of flexible loads with the predicted peak and valley periods of photovoltaic power generation, with the goal of optimizing the low-carbon operation of the coal mine energy system. This is achieved by solving for the day-ahead operating power curve of the flexible loads and coordinating the scheduling of flexible loads and photovoltaic power generation at different times.

[0079] This invention establishes flexible load models for different loads to reflect the relationship between variables and power, and achieves coordinated scheduling of flexible loads and photovoltaic power generation at different times by utilizing the scheduling space of variables and power during operation.

[0080] The invention will now be further described with reference to the accompanying drawings.

[0081] This method for coordinated scheduling of flexible loads and photovoltaic power based on coal mine production characteristics includes the following steps:

[0082] Step 1. Establish an elastic load model based on the constraints of coal mine production characteristics.

[0083] Elastic load models include strong safety constraint elastic load models and non-strong safety constraint elastic load models.

[0084] The strong safety constraint elastic load model includes elastic load models for the mining and transportation process, ventilation, and downhole drainage, as detailed below:

[0085] The elasticity of the load in the mining and transportation process is reflected in the coal mining speed of the coal mining machine, the conveyor speed and capacity during operation. These generally maintain constant values ​​within their own constraints, but there is room for adjustment in speed (capacity) or change of start / stop status based on the system's energy supply and demand balance and coal storage capacity. Therefore, the elastic load model for the mining and transportation process includes the elastic load model for the coal mining machine, the elastic load model for the conveyor belt, and the elastic load models for underground and surface coal bunkers. Specifically:

[0086] ①The elastic load model of the coal mining machine is represented as follows:

[0087]

[0088] In the formula: Let t be the operating power of the coal mining machine at time t, in kW; Let t be the traction speed of the coal mining machine at time t, in m / s; θ is a coefficient related to the structural parameters of the coal mining machine (according to standard ISO5048); This represents the maximum traction speed of the coal mining machine, in m / s.

[0089] ②The elastic load model of the belt conveyor is represented as follows:

[0090]

[0091]

[0092] 0≤v t ≤v max

[0093] In the formula: η is the average power of the belt conveyor in hour t, in kW; μ is a coefficient related to the structure of the belt conveyor (according to standard ISO 5048); η d η m Efficiency, in % for the electric motor and drive system, respectively; v represents the mass per unit length of the belt conveyor during time period t, in kg / m. t W represents the belt's transmission speed, in m / s. t v represents the conveying capacity of the belt conveyor in time period t, in tons per hour; max The maximum transmission speed of the belt is ____ m / s; This represents the upper limit of the mass per unit length that a belt conveyor can bear, expressed in kg / m.

[0094] ③ The elastic load models for underground and surface coal bunkers are expressed as follows:

[0095] If the upper limit of coal bunker capacity is set at 90% and the lower limit at 20%, then...

[0096] C t+1 =C t +θ in,t -θ out,t

[0097] 0.2C N ≤C t ≤0.9C N

[0098] In the formula: θ in,t θ out,t These represent the amount of coal transported into and out of the coal bunker in hour t, in tons; C N C represents the capacity of the coal bunker, in tons. t Let t be the amount of coal stored in the coal bunker in hour t, in tons.

[0099] The flexibility of ventilation load reflects that, while meeting the actual air volume demand underground, the ventilation fan typically operates at a constant state with a power lower than its rated operating power and a reserve of more than 10% of the ventilation volume. There is room for adjustment in ventilation volume (operating power) based on underground ventilation demand and energy system power balance. Therefore, the ventilation flexible load model includes an air volume calculation model and a ventilation fan flexible load model, specifically:

[0100] ①The air volume calculation model is expressed as follows:

[0101] Q P,i =K×(∑Q C,i +∑Q J,i +∑Q D,i +∑Q H,i )

[0102] In the formula: Q P,i For total air volume, m 3 / h; K is the mine ventilation coefficient, with a value of 1.2; Q C,i The required air volume for the coal mining face, in m 3 / h;Q J,i The required air volume at the tunneling face, m 3 / h;QD,i The required air volume (m) for an independent air supply chamber 3 / h;Q H,i For the required air volume in other tunnels, m 3 / h;

[0103] Q C =125k c ×q c

[0104] In the formula: 125 is a conversion factor, based on the requirement that the gas concentration at the coal mining face should be below 0.8%, i.e., 1 / 0.008; k c q is the gas emission imbalance coefficient at the coal mining face, with a value of 2.5; c The relative gas emission rate at the coal mining face, in m 3 / ton, based on on-site measurements at the project site, the value is 5.78;

[0105] Q J =100k J ×q J

[0106] In the formula: 100 is a conversion factor, calculated based on the assumption that the methane concentration at the tunneling face should be less than 1%, i.e., 1 / 0.01; k J The gas outburst imbalance coefficient at the tunneling face is set to 2; q J The relative gas emission rate (m) at the tunneling face 3 / ton, based on on-site measurements at the project site, the value is 2.24;

[0107] Q D =80N D

[0108] In the formula: 80 is the average air volume of a single chamber, in m³. 3 / h;N D The number of chambers;

[0109] Q H =133N H

[0110] In the formula: 133 is the conversion factor for gas emission from a single roadway, calculated based on the assumption that the gas concentration in the roadway should be below 0.75%, i.e., 1 / 0.75; N H This refers to the number of lanes.

[0111] ②The elastic load model of the ventilation fan is expressed as follows:

[0112] P TF,t =f(Q) TF,t ,p TF ,η TF )

[0113] QTF,t ≥Q P

[0114] In the formula: P TF,t Let Q be the operating power of the fan at time t, in kW; TF,t Let m be the air intake volume of the fan at time t. 3 / h;p TF The total air pressure of the fan is expressed in Pa; η TF The value for the operating efficiency of the ventilation fan is 0.9.

[0115] The elasticity of downhole drainage load is reflected in the fact that the drainage pump operates at a constant flow rate (operating power) to meet the safety requirements of downhole water storage. There is room for adjusting the flow rate (operating power) or changing the start-stop state based on the water volume in the downhole water tank and the system's energy supply and demand balance. Therefore, the downhole drainage elastic load model includes the downhole drainage pump elastic load model and the downhole water tank elastic load model, specifically:

[0116] ①The elastic load model of the downhole drainage pump is represented as follows:

[0117] P X =f(κ,g,W) X ,h X ,η X )

[0118] 0≤W X ≤W X，max

[0119] In the formula: X represents the type of drainage pump, which is divided into working, standby, and maintenance; P X κ represents the operating power of type X water pump, in kW; κ is the specific gravity of the medium, taken as 1000 kg / m³ for water. 3 g is the acceleration due to gravity, taken as 9.8 N / kg; W X The operating flow rate (m) of type X water pump 3 / h;h X For type X water pumps, the head is in meters (m); η X The operating efficiency (%) of type X water pump; W X，max The maximum operating flow rate (m) of type X water pump 3 / h.

[0120] ②The elastic load model of the underground water tank is represented as follows:

[0121] The empty capacity of the water tank should be maintained at more than 50% of the total capacity, that is:

[0122] V EM ≥0.5V max

[0123] In the formula: V EM The empty capacity of the water tank is in meters.3 V max The total capacity of the water tank is in meters. 3 .

[0124] The non-strong safety constraint elastic load models include the water source heat pump elastic load model and the wellhead insulation elastic load model, as detailed below:

[0125] The flexibility of a water source heat pump lies in its ability to operate under a constant heat output power, while also having the capacity to adjust the heat output power or change the start-stop state based on the energy supply and demand balance of the system, in conjunction with other heating equipment. Therefore, the flexible load model of a water source heat pump is expressed as follows:

[0126]

[0127] In the formula: P hepm,t The power consumed by the water source heat pump unit during time period t, in kW; H hepm,t The heating capacity of the water source heat pump unit during time period t is expressed in kW; COP is the coefficient of performance of the water source heat pump unit; H exch,t α is the heat absorbed by the water source heat pump unit from the heat source side during time period t, in kW; α is the specific heat capacity of the circulating working fluid, in J / (kg·℃); ο is the mass flow rate of the circulating working fluid, in kg / h; T in T out These are the inlet and outlet temperatures of the water source heat pump evaporator, respectively, in °C.

[0128] The elasticity of the wellhead frost protection load is reflected in the fact that, under normal operating conditions, the wellbore insulation heat demand is kept constant while meeting the average ventilation volume. There is room for adjusting the heat power by increasing or decreasing the actual frost protection demand at the wellhead and balancing the system's energy supply and demand under varying ventilation volumes. Therefore, the elastic load model for wellhead insulation is expressed as follows:

[0129] H FD =f(Q) TF,ave ,ρ inair C ENT ,T mix ,T low )

[0130] H FD,t ≥H FD

[0131] In the formula: H FD The basic thermal power required for wellhead freeze protection, in kW; Q TF,ave The average air intake at the wellhead, in meters (m) 3 / s;ρ inair For air density, take the value as 1.28 kg / m³. 3 C ENT The specific heat capacity of air at constant pressure is taken as 1.01 kJ / (kg·℃); T mixT represents the temperature after the hot and cold air are mixed, in °C. low The lowest ambient temperature in winter, °C; H FD,t Let t be the thermal power required for wellhead freeze protection, in kW.

[0132] Step 2. Based on the elastic load model, determine the known parameters and decision variables, and construct the constraint relationships. The specific constraint relationships are as follows:

[0133] ① The upper and lower limits of power consumption for flexible loads are expressed as follows:

[0134] 0≤P t ≤P max

[0135] In the formula: P t P represents the electrical power of the elastic load at time t, in kW. max The maximum operating electrical power of the flexible load is expressed in kW.

[0136] ② Elastic load ramping constraint

[0137] To prevent the flexible load from switching between a stopped and high-power operating state at adjacent operating times, the ramp-up power of the flexible load is limited. The ramp-up constraint of the flexible load is expressed as follows:

[0138] -η p P max ≤P t+1 -P t ≤η p P max

[0139] In the formula: η p The percentage of elastic load ramp rate, %; P t+1 Let be the electrical power of the elastic load at time t+1, in kW.

[0140] ③ The power balance constraints of the energy system are expressed as follows:

[0141] P grid,t +P gen,t =P load,t

[0142] H buy,t +H gen,t =H load,t

[0143] In the formula: P grid,t Let P be the purchased power at time t, in kW; gen,t P represents the power output of the system's built-in generator at time t, in kW. load,t Let t be the total electrical load power of all electrical equipment at time t, expressed in kW or H. buy,t The purchased heat power at time t is expressed in kW and H. gen,tThe heating power of the system's built-in heating equipment at time t is expressed in kW and H. load,t Let t be the total heat load power required by all heat power demands at time t, in kW.

[0144] Step 3. Construct the objective function for the coordinated scheduling of flexible loads and photovoltaics, and solve it using the Gurobi solver.

[0145] Based on the elastic load model and constraints, and combined with peak-valley electricity prices, the scheduling space of the elastic load is used to adjust the peak and valley periods of load energy consumption, matching the day-ahead forecast results of photovoltaic power generation. With the goal of optimizing the low-carbon operation of the coal mine energy system, the day-ahead operating state power curve of the elastic load is obtained by solving the problem, so as to coordinate the scheduling of the elastic load and photovoltaic power generation at different times.

[0146] The objective function for coordinated scheduling of flexible loads and photovoltaic power is expressed as follows:

[0147] Z = β grid P grid +β pv P pv +β gas GAS

[0148] In the formula: Z represents the total carbon emissions of the system, tCO2, which is measured in tons of CO2; β grid For the carbon emissions per unit of the power grid, tCO2 / kWh; β pv tCO2 / kWh represents the carbon emissions per unit of photovoltaic power generation; β gas Carbon emissions per unit of natural gas, tCO2 / MJ; P grid Total purchased electricity, kWh; P pv 1 represents the total photovoltaic power generation, in kWh; GAS represents the total calorific value of natural gas, in MJ.

[0149] The following simulation uses operational data from a coal mine in Shanxi Province as a reference. The simulation is performed using MATLAB_R2021b with the Gurobi 10.0.1 solver. The simulation results include load changes before and after system scheduling, power purchase after scheduling, and photovoltaic effects. Figure 2 As shown, the carbon emissions from electricity purchases, photovoltaic power, and natural gas after dispatch are as follows: Figure 3 As shown in Table 1, the results of the low-carbon optimization comparison between flexible load and photovoltaic coordinated dispatch are presented in the simulation analysis. Compared with constant state operation, although the energy purchase cost of coordinated dispatch operation increases by 2,300 yuan, CO2 emissions are reduced by 0.93887 tons, thus achieving low-carbon operation of the coal mine energy system.

[0150] Table 1 Comparison Results of System Low-Carbon Performance

[0151]

[0152] It is evident that the flexible load and photovoltaic coordinated scheduling method based on coal mine production characteristics can improve the matching degree between photovoltaic power generation in the mining area and coal mine source load, reduce resource and energy waste, and achieve low-carbon and efficient operation of coal mines. It can provide theoretical basis and data support for the low-carbon optimal coupling of photovoltaic power generation in the mining area and coal mine source load.

Claims

1. A method for coordinated scheduling of flexible loads and photovoltaic power based on coal mine production characteristics constraints, characterized in that, Specifically, the following steps are included: Step 1. Based on the constraints of coal mine production characteristics, establish a flexible load model. The flexible load model includes a strong safety constraint flexible load model and a non-strong safety constraint flexible load model. The strong safety constraint flexible load model includes a mining and transportation link flexible load model, a ventilation flexible load model, and an underground drainage flexible load model. The non-strong safety constraint flexible load model includes a water source heat pump flexible load model and a wellhead insulation flexible load model. Step 2. Based on the elastic load model, determine the known parameters and decision variables, and construct the constraint relationships; ① The upper and lower limits of power consumption for flexible loads are expressed as follows: 0≤P t ≤P max In the formula: P t P represents the electrical power of the elastic load at time t, in kW. max The maximum operating electrical power of the flexible load is expressed in kW. ② Elastic load ramping constraint To prevent the flexible load from switching between a stopped and high-power operating state at adjacent operating times, the ramp-up power of the flexible load is limited. The ramp-up constraint of the flexible load is expressed as follows: -η p P max ≤P t+1 -P t ≤η p P max In the formula: η p The percentage of elastic load ramp rate, %; P t+1 Let be the electrical power of the elastic load at time t+1, in kW; ③ The power balance constraints of the energy system are expressed as follows: P grid,t +P gen,t =P load,t H buy,t +H gen,t =H load,t In the formula: P grid,t Let P be the purchased power at time t, in kW; gen,t P represents the power output of the system's built-in generator at time t, in kW. load,t Let t be the total electrical load power of all electrical equipment at time t, expressed in kW or H. buy,t The purchased heat power at time t is expressed in kW and H. gen,t The heating power of the system's built-in heating equipment at time t is expressed in kW and H. load,t Let t be the total heat load power demanded by all heat sources at time t, in kW; Step 3. Construct the objective function for coordinated scheduling of flexible loads and photovoltaic power generation, and solve it to obtain the day-ahead operating power curve of the flexible loads, and carry out coordinated scheduling of flexible loads and photovoltaic power generation at different times; The objective function for coordinated scheduling of flexible loads and photovoltaic power is expressed as follows: Z=β grid P grid +b pv P pv +b gas GAS In the formula: Z represents the total carbon emissions of the system, tCO2; β grid For the carbon emissions per unit of the power grid, tCO2 / kWh; β pv tCO2 / kWh represents the carbon emissions per unit of photovoltaic power generation; β gas Carbon emissions per unit of natural gas, tCO2 / MJ; P grid Total purchased electricity, kWh; P pv 1 represents the total photovoltaic power generation, in kWh; GAS represents the total calorific value of natural gas, in MJ.

2. The method for coordinated scheduling of elastic loads and photovoltaic power based on coal mine production characteristics constraints according to claim 1, characterized in that, In Step 1, the elastic load model for the mining and transportation process includes the elastic load model for the coal mining machine, the elastic load model for the belt conveyor, and the elastic load models for the underground and surface coal bunkers. Specifically: ①The elastic load model of the coal mining machine is represented as follows: In the formula: Let t be the operating power of the coal mining machine at time t, in kW; Let t be the traction speed of the coal mining machine at time t, in m / s; θ is a coefficient related to the structural parameters of the coal mining machine. This represents the maximum traction speed of the coal mining machine, in m / s; ②The elastic load model of the belt conveyor is represented as follows: 0≤v t ≤v max In the formula: η is the average power of the belt conveyor in hour t, in kW; μ is a coefficient related to the structure of the belt conveyor; η d η m Efficiency, in % for the electric motor and drive system, respectively; v represents the mass per unit length of the belt conveyor during time period t, in kg / m. t W represents the belt's transmission speed, in m / s. t v represents the conveying capacity of the belt conveyor in time period t, in tons per hour; max The maximum transmission speed of the belt is ____ m / s; This represents the upper limit of the mass per unit length that a belt conveyor can withstand, expressed in kg / m. ③ The elastic load models for underground and surface coal bunkers are expressed as follows: If the upper limit of coal bunker capacity is set at 90% and the lower limit at 20%, then... C t+1 =C t +θ in,t -θ out,t 0.2C N ≤C t ≤0.9C N In the formula: θ in,t θ out,t These represent the amount of coal transported into and out of the coal bunker in hour t, in tons; C N C represents the capacity of the coal bunker, in tons. t Let t be the amount of coal stored in the coal bunker in hour t, in tons.

3. The method for coordinated scheduling of elastic loads and photovoltaic power based on coal mine production characteristics constraints according to claim 1, characterized in that, In Step 1, the ventilation flexible load model includes the air volume calculation model and the ventilation fan flexible load model, specifically: ①The air volume calculation model is expressed as follows: Q P,i =K×(∑Q C,i +∑Q J,i +∑Q D,i +∑Q H,i ) In the formula: Q P,i For total air volume, m 3 / h; K is the mine ventilation coefficient, with a value of 1.2; Q C,i The required air volume for the coal mining face, in m 3 / h;Q J,i The required air volume at the tunneling face, m 3 / h;Q D,i The required air volume (m) for an independent air supply chamber 3 / h;Q H,i For the required air volume in other tunnels, m 3 / h; Q C =125k c ×q c In the formula: 125 is the conversion factor; k c q is the gas emission imbalance coefficient at the coal mining face, with a value of 2.5; c The relative gas emission rate at the coal mining face, in m 3 / ton; Q J =100k J ×q J In the formula: 100 is the conversion factor; k J The gas outburst imbalance coefficient at the tunneling face is set to 2; q J The relative gas emission rate (m) at the tunneling face 3 / ton; Q D =80N D In the formula: 80 is the average air volume of a single chamber, in m³. 3 / h;N D The number of chambers; Q H =133N H In the formula: 133 is the conversion factor for gas emission in a single roadway; N H The number of lanes; ②The elastic load model of the ventilation fan is expressed as follows: P TF,t =f(Q TF,t ,p TF ,η TF ) Q TF,t ≥Q P In the formula: P TF,t Let Q be the operating power of the fan at time t, in kW; TF,t Let m be the air intake volume of the fan at time t. 3 / h;p TF The total air pressure of the fan is Pa; η TF For the operating efficiency of the ventilation fan, %.

4. The method for coordinated scheduling of elastic loads and photovoltaic power based on coal mine production characteristics constraints according to claim 1, characterized in that, In Step 1, the downhole drainage elastic load model includes the downhole drainage pump elastic load model and the downhole water tank elastic load model, specifically: ①The elastic load model of the downhole drainage pump is represented as follows: P X =f(κ,g,W X ,h X ,or X ) 0≤W X ≤W X，max In the formula: X represents the type of drainage pump; P X κ represents the operating power of type X water pump, in kW; κ represents the specific gravity of the medium, in kg / m³. 3 g is the acceleration due to gravity, taken as 9.8 N / kg; W X The operating flow rate (m) of type X water pump 3 / h;h X Let X be the head of the type X water pump, in meters (m). η X The operating efficiency of type X water pump, %; W X，max The maximum operating flow rate (m) of type X water pump 3 / h; ②The elastic load model of the underground water tank is represented as follows: The empty capacity of the water tank should be maintained at more than 50% of the total capacity, that is: V EM ≥0.5V max In the formula: V EM The empty capacity of the water tank is in meters. 3 V max The total capacity of the water tank is in meters. 3 .

5. The method for coordinated scheduling of elastic loads and photovoltaic power based on coal mine production characteristics constraints according to claim 1, characterized in that, In Step 1, the elastic load model of the water source heat pump is represented as follows: In the formula: P hepm,t The power consumed by the water source heat pump unit during time period t, in kW; H hepm,t The heating capacity of the water source heat pump unit during time period t is expressed in kW; COP is the coefficient of performance of the water source heat pump unit; H exch,t α is the heat absorbed by the water source heat pump unit from the heat source side during time period t, in kW; α is the specific heat capacity of the circulating working fluid, in J / (kg·℃); ο is the mass flow rate of the circulating working fluid, in kg / h; T in T out These are the inlet and outlet temperatures of the water source heat pump evaporator, respectively, in °C.

6. The method for coordinated scheduling of elastic loads and photovoltaic power based on coal mine production characteristics constraints according to claim 1, characterized in that, In Step 1, the wellhead insulation elastic load model is represented as follows: H FD =f(Q TF,ave ,ρ inair ,C ENT ,T mix ,T low ) H FD,t ≥H FD Where: H FD The basic thermal power required for wellhead freeze protection, in kW; Q TF,ave The average air intake at the wellhead, in meters (m) 3 / s;ρ inair For air density, take the value as 1.28 kg / m³. 3 C ENT The specific heat capacity of air at constant pressure is taken as 1.01 kJ / (kg·℃); T mix T represents the temperature after the hot and cold air mixes, in °C. low The lowest ambient temperature in winter, °C; H FD,t Let t be the thermal power required for wellhead freeze protection, in kW.

7. The method for coordinated scheduling of elastic loads and photovoltaic power based on coal mine production characteristics constraints according to claim 1, characterized in that, Step 3 uses the Gurobi solver to perform calculations and solve the problem.

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