Method for calculating flexibility supply of solid heat storage electric heat microgrid based on conversion coefficient
By establishing a flexible supply model for cogeneration units, solid thermal storage, and thermal storage tanks, and rationally allocating the flexible supply of each unit, the problem of unbalanced flexible supply in existing technologies is solved, and the safety and scheduling convenience of the electric heating microgrid are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEFEI UNIV OF TECH
- Filing Date
- 2023-05-15
- Publication Date
- 2026-06-23
AI Technical Summary
Existing technologies fail to accurately measure the flexibility available to the system at different times, resulting in an imbalance between the supply and demand of system flexibility, which affects system reliability and scheduling complexity.
A calculation method for the flexible supply of a microgrid with solid thermal storage based on the conversion coefficient is established. By establishing a flexible supply model for cogeneration units, solid thermal storage and thermal storage tanks, the flexible supply of each device is reasonably allocated, and the coupling relationship between each device is considered to calculate the flexible supply of the microgrid at each time.
It improves the safety and scheduling convenience of the electric heating microgrid, ensures the flexible balance between supply and demand at all times, and enhances the reliability and scheduling accuracy of the system.
Smart Images
Figure CN116562573B_ABST
Abstract
Description
Technical Field
[0001] This invention proposes a method for calculating the flexible supply of a microgrid containing solid thermal storage based on a conversion coefficient, taking into account the different output characteristics and magnitudes of various devices in the system at different times. Background Technology
[0002] With a high proportion of new energy grid connection, the large increase in demand for new energy grid connection has put forward new requirements for the flexible operation capability of regional integrated energy systems. Accurately quantifying the flexibility requirements caused by the uncertainty of new energy and load output during the day-ahead dispatch phase of microgrids and rationally arranging the output of each device during the day-ahead dispatch phase can ensure sufficient flexibility of the system at all times, improve system safety, and avoid casualties or economic losses caused by insufficient system flexibility.
[0003] Currently, research on flexibility supply calculation mainly focuses on the flexibility calculation and superposition of individual devices, and has failed to establish a flexibility supply model that accurately considers the coupling relationship between various devices. On the one hand, since the flexibility supply of the system at each moment cannot be accurately measured, it will lead to an imbalance between the system's flexibility supply and flexibility demand, and the system's reliability cannot be guaranteed. On the other hand, in the day-ahead scheduling optimization phase, optimizing each device according to the inaccurate flexibility supply often leads to additional scheduling within the day, which increases the scheduling complexity. Summary of the Invention
[0004] To overcome the shortcomings of the prior art, this invention provides a method for calculating the flexible supply of a microgrid with solid thermal storage based on a conversion coefficient. This method aims to accurately calculate the flexible supply of the microgrid at various times, thereby improving the safety and scheduling convenience of the microgrid.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0006] The present invention provides a method for calculating the flexible supply of a microgrid containing solid thermal storage based on a conversion coefficient, characterized by the following steps:
[0007] Step 1: Establish a flexible power supply model for cogeneration units based on the electric heating operating zone and ramp-up power limitations, and calculate the upward or downward power flexibility supply that the cogeneration units can provide at different times:
[0008] Step 1.1: Use equation (1) to obtain the upward power flexibility supply of the cogeneration unit at time t.
[0009]
[0010] In equation (1), F max P represents the maximum fuel input for a combined heat and power (CHP) unit. CHP,tLet Q be the power output of the combined heat and power unit at time t. CHP,t Let β be the heating power of the cogeneration unit at time t. h and β e These represent fuel consumption per unit of power generation and heating, respectively; k CHP,ramp Δt represents the ramp rate of the cogeneration unit, and Δt represents the unit scheduling time of the cogeneration unit.
[0011] Step 1.2: Use equation (2) to obtain the downward power flexibility supply of the cogeneration unit at time t.
[0012]
[0013] In equation (2), F min Q represents the minimum fuel input for a combined heat and power (CHP) unit, r represents the electro-thermal ratio of the CHP unit during back pressure operation, and Q represents the total energy input. max This is the maximum heating capacity of the combined heat and power unit;
[0014] Step 2: Establish a solid thermal storage flexibility supply model based on the comprehensive heat exchange process of the thermal storage body, and calculate the upward or downward electrical flexibility supply that solid thermal storage can provide at different times:
[0015] Step 2.1: Use equation (3) to obtain the upward electrical flexibility supply of solid thermal storage at time t.
[0016]
[0017] In equation (3), This represents the maximum heating power of the solid thermal storage heating wire. Let T be the heating power of the heating wire for solid thermal storage at time t. H,t Let T be the temperature of the solid thermal storage at time t. max The highest temperature of the solid thermal storage body is m, where m is the mass of the thermal storage body, and c is the temperature of the solid thermal storage body. H The specific heat capacity of the heat storage body;
[0018] Step 2.1: Use equation (4) to obtain the downward electrical flexibility supply of solid thermal storage at time t.
[0019]
[0020] In equation (4), Let T be the minimum heating power of the solid thermal storage heating wire at time t. min This is the lowest temperature of a solid thermal storage body.
[0021] Step 3: Establish a flexible supply model for the thermal storage tank based on the remaining heat capacity and the limitations of charging and discharging heat power, and calculate the flexible supply of upward or downward thermal energy that the thermal storage tank can provide at different times:
[0022] Step 3.1: Use equation (5) to obtain the upward thermal energy flexibility supply of the thermal storage tank at time t.
[0023]
[0024] In equation (5), Q is the maximum heat release power of the thermal storage tank. HS,t Let S be the heat release power of the thermal storage tank at time t. HS,t Let be the remaining heat in the heat storage tank at time t;
[0025] Step 3.2: Use equation (6) to obtain the downward thermal energy flexibility supply of the thermal storage tank at time t.
[0026]
[0027] In equation (6), This represents the minimum heat dissipation power of the thermal storage tank. This represents the maximum heat capacity of the thermal storage tank.
[0028] Step 4: Establish a calculation model for the flexible supply of a microgrid with solid thermal storage based on the conversion coefficient. Compare the conversion coefficients of solid thermal storage and cogeneration units to rationally allocate the flexible supply of thermal energy from the storage tanks, and calculate the upward or downward electrical flexibility supply of the microgrid.
[0029] Step 4.1: Use equation (7) to obtain the electrothermal conversion coefficient tr of the cogeneration unit at time t. chp,t :
[0030]
[0031] In equation (7), ΔFe chp,t Let ΔFh be the change in electrical flexibility of the cogeneration unit at time t. chp,t Let be the change in thermal flexibility of the cogeneration unit at time t;
[0032] Step 4.2: Use equation (8) to obtain the electrothermal conversion coefficient tr of the solid thermal storage at time t. cr,t :
[0033]
[0034] In equation (8), ΔFe cr,t Let ΔFh be the change in electrodynamic flexibility of the solid thermal storage at time t. cr,t Let be the change in thermal flexibility of solid thermal storage at time t;
[0035] Step 4.3: Use equation (9) to obtain the upward supply of the electric heating microgrid flexibility at time t.
[0036]
[0037] In equation (9), The upward flexibility supply for the coupled operation of the cogeneration unit, solid thermal storage and thermal storage tank at time t is obtained by equation (10);
[0038]
[0039] In equation (10), The maximum downward thermal energy flexibility supply of the cogeneration unit at time t is obtained from equation (11); The maximum upward thermal energy flexibility supply of the cogeneration unit at time t is obtained from equation (12); The maximum downward thermal energy flexibility supply for solid thermal storage at time t is obtained from equation (13);
[0040]
[0041]
[0042]
[0043] In equation (13), The thermal storage flexibility is calculated and obtained from equation (14); FE cr,start，1 FE is the auxiliary variable for the first solid thermal storage flexibility. cr,start，2 It is an auxiliary variable for the flexibility of the second solid thermal storage, and is obtained from equation (15);
[0044]
[0045]
[0046] Step 4.4: Use equation (16) to obtain the downward supply of the electrothermal microgrid flexibility at time t.
[0047]
[0048] In equation (16), The downward flexibility supply for the coupled operation of cogeneration units, solid thermal storage and thermal storage tanks is obtained from equation (17);
[0049]
[0050] In equation (17), The flexibility of the cogeneration unit is calculated using equation (18). The maximum upward thermal energy flexibility of solid thermal storage is supplied, and is obtained from equation (19);
[0051]
[0052]
[0053] In equation (19), FE cr,start,3 FE is the auxiliary variable for the third solid thermal storage flexibility. cr,start，4 As the fourth auxiliary variable for the flexibility of solid thermal storage, FE cr,start，5 FE is the fifth auxiliary variable for the flexibility of solid thermal storage. cr,start，6 As the sixth auxiliary variable for the flexibility of solid thermal storage, we have:
[0054]
[0055] The present invention provides an electronic device, comprising a memory and a processor, wherein the memory is used to store a program that supports the processor in executing the calculation method for flexible supply of a microgrid containing solid thermal energy storage, and the processor is configured to execute the program stored in the memory.
[0056] The present invention discloses a computer-readable storage medium on which a computer program is stored, wherein the computer program, when executed by a processor, performs the steps of the method for calculating the flexible supply of a microgrid containing solid thermal energy storage.
[0057] Compared with existing technologies, the beneficial effects of this invention are reflected in:
[0058] 1. This invention first establishes a flexible supply model for cogeneration units, solid thermal storage, and thermal storage tanks, accurately measuring the flexible supply provided by each unit when it is running alone, which helps to rationally plan flexible resources and improve system reliability.
[0059] 2. Based on the above model, this invention further establishes a comprehensive flexible supply model that accurately considers the coupling relationship of each device, realizing the accurate calculation of the flexible supply of the electric heating microgrid at each moment, providing a reference for the day-ahead scheduling optimization of the electric heating microgrid, and helping to improve the convenience and safety of the electric heating microgrid scheduling. Attached Figure Description
[0060] Figure 1 This is a schematic diagram of the calculation method for the flexible supply of a microgrid containing solid thermal storage based on the conversion coefficient, according to the present invention. Detailed Implementation
[0061] In this embodiment, as Figure 1As shown, a method for calculating the flexible supply of a microgrid containing solid thermal energy storage based on the conversion coefficient is performed according to the following steps:
[0062] Step 1: Establish a flexible power supply model for cogeneration units based on the electric heating operating zone and ramp-up power limitations, and calculate the upward or downward power flexibility supply that the cogeneration units can provide at different times:
[0063] Step 1.1: Use equation (21) to obtain the upward power flexibility supply of the cogeneration unit at time t.
[0064]
[0065] In equation (21), F max P represents the maximum fuel input for a combined heat and power (CHP) unit. CHP,t Let Q be the power output of the combined heat and power unit at time t. CHP,t Let β be the heating power of the cogeneration unit at time t. h and β e These represent the fuel consumption per unit of power generation and heating, respectively. The specific values depend on the characteristics of the equipment; here they are set to 0.31 and 2.4, respectively. CHP,ramp Δt represents the ramp rate of the cogeneration unit, and Δt represents the unit scheduling time of the cogeneration unit.
[0066] Step 1.2: Use equation (22) to obtain the downward power flexibility supply of the cogeneration unit at time t.
[0067]
[0068] In equation (22), F min Q represents the minimum fuel input for a combined heat and power (CHP) unit, r represents the electro-thermal ratio of the CHP unit under back pressure operation, and the power supply and heating power of the CHP unit are proportional under back pressure operation. max This is the maximum heating capacity of the combined heat and power unit;
[0069] Step 2: Establish a flexible supply model for solid thermal storage based on the comprehensive heat exchange process of the thermal storage body. Calculate the upward or downward electrical flexibility supply that the solid thermal storage can provide at different times. The charging power of the thermal storage body is not only affected by the current temperature and heat release power of the thermal storage body, but must also meet the requirement of not exceeding the designed maximum charging power.
[0070] Step 2.1: Use equation (23) to obtain the upward electrical flexibility supply of solid thermal storage at time t.
[0071]
[0072] In equation (23), This represents the maximum heating power of the solid thermal storage heating wire. Let T be the heating power of the heating wire for solid thermal storage at time t. H,t Let T be the temperature of the solid thermal storage at time t. max The highest temperature of the solid thermal storage body is m, where m is the mass of the thermal storage body, and c is the temperature of the solid thermal storage body. H The specific heat capacity of the heat storage body;
[0073] Step 2.1: Use equation (24) to obtain the downward electrical flexibility supply FE of the solid thermal storage at time t. C do R ,w t n:
[0074]
[0075] In equation (24), Let T be the minimum heating power of the solid thermal storage heating wire at time t. min This is the lowest temperature of a solid thermal storage body.
[0076] Step 3: Establish a flexible supply model for the thermal storage tank based on the remaining heat capacity and the limitations of charging and discharging heat power, and calculate the flexible supply of upward or downward thermal energy that the thermal storage tank can provide at different times:
[0077] Step 3.1: Use equation (25) to obtain the upward thermal energy flexibility supply of the thermal storage tank at time t.
[0078]
[0079] In equation (25), Q is the maximum heat release power of the thermal storage tank. HS,t Let S be the heat release power of the thermal storage tank at time t. HS,t Let be the remaining heat in the heat storage tank at time t;
[0080] Step 3.2: Use equation (26) to obtain the downward thermal energy flexibility supply of the thermal storage tank at time t.
[0081]
[0082] In equation (26), This represents the minimum heat dissipation power of the thermal storage tank. This represents the maximum heat capacity of the thermal storage tank.
[0083] Step 4: Establish a calculation model for the flexible supply of a microgrid with solid thermal storage based on the conversion coefficient. The electrothermal conversion coefficient varies with different thermal outputs of the unit. Compare the conversion coefficients of solid thermal storage and cogeneration units to rationally allocate the flexible supply of thermal energy from the thermal storage tanks. Calculate the upward or downward flexible supply of the microgrid. Here, only the case where the heating power of the cogeneration unit is greater than the flexibility allocation point of the cogeneration unit is considered:
[0084] Step 4.1: Use equation (27) to obtain the electrothermal conversion coefficient tr of the cogeneration unit at time t. chp,t :
[0085]
[0086] In equation (27), ΔFe chp,t Let ΔFh be the change in electrical flexibility of the cogeneration unit at time t. chp,t Let be the change in thermal flexibility of the cogeneration unit at time t;
[0087] Step 4.2: Use equation (28) to obtain the electrothermal conversion coefficient tr of the solid thermal storage at time t. cr,t :
[0088]
[0089] In equation (28), ΔFe cr,t Let ΔFh be the change in electrodynamic flexibility of the solid thermal storage at time t. cr,t Let be the change in thermal flexibility of solid thermal storage at time t;
[0090] Step 4.3: Use equation (29) to obtain the upward supply of the electric heating microgrid flexibility at time t.
[0091]
[0092] In equation (29), The upward flexibility supply for the coupled operation of the cogeneration unit, solid thermal storage and thermal storage tank at time t is obtained by equation (30);
[0093]
[0094] In equation (30), The maximum downward thermal energy flexibility supply of the cogeneration unit at time t is obtained from equation (31);
[0095]
[0096] In equation (30), The maximum upward thermal energy flexibility supply of the cogeneration unit at time t is obtained from equation (32);
[0097]
[0098] In equation (30), The maximum downward thermal energy flexibility supply for solid thermal storage at time t is obtained from equation (33);
[0099]
[0100] In equation (33), The point for determining the flexibility of thermal storage is determined by the real-time output state of solid thermal storage and is obtained from equation (34);
[0101]
[0102] In equation (33), FE cr,start，1 FE is the auxiliary variable for the first solid thermal storage flexibility. cr,start，2 The second solid thermal storage flexibility auxiliary variable is obtained from equation (35);
[0103]
[0104] Step 4.4: Use equation (36) to obtain the downward supply of the electrothermal microgrid flexibility at time t.
[0105]
[0106] In equation (36), Downward flexibility supply of cogeneration units, solid thermal storage and thermal storage tank coupled operation, and obtained by equation (37);
[0107]
[0108] In equation (37), The flexibility point of the cogeneration unit is determined by the real-time output status of the cogeneration unit and is obtained by equation (38).
[0109]
[0110] In equation (37), The maximum upward thermal energy flexibility of solid thermal storage is supplied, and is obtained from equation (39);
[0111]
[0112] In equation (39), FE cr,start,3 FE is the auxiliary variable for the third solid thermal storage flexibility. cr,start，4 As the fourth auxiliary variable for the flexibility of solid thermal storage, FE cr,start，5FE is the fifth auxiliary variable for the flexibility of solid thermal storage. cr,start，6 It is the auxiliary variable for the flexibility of the 6th solid thermal storage, and is obtained from equation (40);
[0113]
[0114] In summary, the method for calculating the flexible supply of a microgrid with solid thermal storage based on conversion coefficient proposed in this invention first calculates the flexible supply that the cogeneration unit, solid thermal storage, and thermal storage tank can provide when operating independently. Then, it compares the conversion coefficients of solid thermal storage and the cogeneration unit, rationally allocates the flexible supply of thermal energy from the thermal storage tank, and calculates the flexible supply of the microgrid when all three operate simultaneously.
[0115] In this embodiment, an electronic device includes a memory and a processor. The memory stores a program that supports the processor in executing the above-described method, and the processor is configured to execute the program stored in the memory.
[0116] In this embodiment, a computer-readable storage medium stores a computer program, which is executed by a processor to perform the steps of the above method.
Claims
1. A method for calculating the flexible supply of a microgrid containing solid thermal energy storage based on a conversion coefficient, characterized in that, The procedure is as follows: Step 1: Establish a flexible power supply model for cogeneration units based on the electric heating operating zone and ramp-up power limitations, and calculate the upward or downward power flexibility supply that the cogeneration units can provide at different times: Step 1.1: Use equation (1) to obtain the upward power flexibility supply of the cogeneration unit at time t. : (1) In equation (1), This represents the maximum fuel input for a combined heat and power (CHP) unit. Let t be the power supply capacity of the combined heat and power unit. Let t be the heating capacity of the cogeneration unit. and These are the fuel consumption per unit of power generation and heating, respectively. For the ramp-up rate of combined heat and power units, The unit dispatch time for combined heat and power units; Step 1.2: Use equation (2) to obtain the downward power flexibility supply of the cogeneration unit at time t. : (2) In equation (2), Here, r represents the minimum fuel input for the combined heat and power (CHP) unit, and r is the electro-thermal ratio of the CHP unit during back pressure operation. This is the maximum heating capacity of the combined heat and power unit; Step 2: Establish a solid thermal storage flexibility supply model based on the comprehensive heat exchange process of the thermal storage body, and calculate the upward or downward electrical flexibility supply that solid thermal storage can provide at different times: Step 2.1: Use equation (3) to obtain the upward electrical flexibility supply of solid thermal storage at time t. : (3) In equation (3), This represents the maximum heating power of the solid thermal storage heating wire. Let be the heating power of the heating wire for solid heat storage at time t. Let t be the temperature of the solid thermal storage medium. This represents the highest temperature of a solid thermal storage medium. For the mass of the thermal storage body, The specific heat capacity of the heat storage body; Step 2.1: Use equation (4) to obtain the downward electrical flexibility supply of solid thermal storage at time t. : (4) In equation (4), Let be the minimum heating power of the solid thermal storage heating wire at time t. This is the lowest temperature of a solid thermal storage body. Step 3: Establish a flexible supply model for the thermal storage tank based on the remaining heat capacity and the limitations of charging and discharging heat power, and calculate the flexible supply of upward or downward thermal energy that the thermal storage tank can provide at different times: Step 3.1: Use equation (5) to obtain the upward thermal energy flexibility supply of the thermal storage tank at time t. : (5) In equation (5), This represents the maximum heat release capacity of the thermal storage tank. Let be the heat release power of the heat storage tank at time t. Let be the remaining heat in the heat storage tank at time t; Step 3.2: Use equation (6) to obtain the downward thermal energy flexibility supply of the thermal storage tank at time t. : (6) In equation (6), This represents the minimum heat dissipation power of the thermal storage tank. This represents the maximum heat capacity of the thermal storage tank. Step 4: Establish a calculation model for the flexible supply of a microgrid with solid thermal storage based on the conversion coefficient. Compare the conversion coefficients of solid thermal storage and cogeneration units to rationally allocate the flexible supply of thermal energy from the storage tanks, and calculate the upward or downward electrical flexibility supply of the microgrid. Step 4.1: Use equation (7) to obtain the electrothermal conversion coefficient of the cogeneration unit at time t. : (7) In equation (7), Let be the change in electrical flexibility of the cogeneration unit at time t. Let be the change in thermal flexibility of the cogeneration unit at time t; Step 4.2: Use equation (8) to obtain the electrothermal conversion coefficient of solid thermal storage at time t. : (8) In equation (8), Let be the change in electroflexibility of the solid thermal storage at time t. Let be the change in thermal flexibility of solid thermal storage at time t; Step 4.3: Use equation (9) to obtain the upward supply of the electric heating microgrid flexibility at time t. : (9) In equation (9), The upward flexibility supply for the coupled operation of the cogeneration unit, solid thermal storage and thermal storage tank at time t is obtained by equation (10); (10) In equation (10), The maximum downward thermal energy flexibility supply of the cogeneration unit at time t is obtained from equation (11); The maximum upward thermal energy flexibility supply of the cogeneration unit at time t is obtained from equation (12); The maximum downward thermal energy flexibility supply for solid thermal storage at time t is obtained from equation (13); (11) (12) (13) In equation (13), The points for thermal storage flexibility are obtained from equation (14); As an auxiliary variable for the flexibility of the first solid thermal storage, It is an auxiliary variable for the flexibility of the second solid thermal storage, and is obtained from equation (15); (14) (15) Step 4.4: Use equation (16) to obtain the downward supply of the electrothermal microgrid flexibility at time t. : (16) In equation (16), The downward flexibility supply for the coupled operation of cogeneration units, solid thermal storage and thermal storage tanks is obtained from equation (17); (17) In equation (17), The flexibility of the cogeneration unit is calculated using equation (18). The maximum upward thermal energy flexibility of solid thermal storage is supplied, and is obtained from equation (19); (18) (19) In equation (19), As the third auxiliary variable for the flexibility of solid thermal storage, As the fourth auxiliary variable for the flexibility of solid thermal storage, As the fifth auxiliary variable for the flexibility of solid thermal storage, As the sixth auxiliary variable for the flexibility of solid thermal storage, we have: (20)。 2. An electronic device, comprising a memory and a processor, characterized in that, The memory is used to store a program that supports the processor in executing the flexible supply calculation method for the solid thermal energy storage microgrid of claim 1, and the processor is configured to execute the program stored in the memory.
3. A computer-readable storage medium storing a computer program, characterized in that, The computer program, when run by the processor, executes the steps of the method for calculating the flexible supply of a microgrid containing solid thermal storage as described in claim 1.