A method and system for operation optimization of an electro-thermal coupling integrated energy system

Abstract

The application discloses a kind of electric heating coupling comprehensive energy system operation optimization method and system, it is related to electric heating coupling technical field, method includes: based on the measured data set of electric heating coupling comprehensive energy system determines the minimum inertia demand of power system;Real-time inertia constraint, system operation power balance constraint, system equipment output limit constraint, system equipment operation limit constraint and heating terminal indoor temperature constraint are established, then with the minimum of electric heating coupling comprehensive energy system operation cost as target establishes electric heating system frequency modulation strategy model;The model is solved to obtain the optimal frequency modulation result of power system;When the current inertia of system is less than the current minimum inertia demand value, according to optimal frequency modulation result, power system is modulated, until the frequency data of power system after frequency modulation meets preset frequency range, exit frequency modulation.The application is based on inertia and optimizes configuration to frequency modulation power, to improve the utilization efficiency of comprehensive energy.

Description

Technical Field

[0001] This invention relates to the field of electrothermal coupling technology, and in particular to a method and system for optimizing the operation of an integrated energy system with electrothermal coupling that participates in primary frequency regulation of a power system. Background Technology

[0002] Building a new power system with renewable energy as the mainstay is an effective way to address the dual pressures of the primary energy crisis and environmental pollution. Large-scale integration of renewable energy into the grid via converters reduces the overall inertia of the power system, weakens its frequency regulation capability, and is detrimental to the system's frequency stability. In severe cases, this can lead to a collapse in power system frequency stability and even cause widespread blackouts.

[0003] Integrated energy systems are a crucial component in building new power systems, characterized by multi-energy complementarity, maximizing the absorption of wind and solar renewable energy, and improving overall energy utilization efficiency. Electrothermal coupled integrated energy systems represent an important form of multi-energy complementarity and synergy. Considering the slow-dynamic characteristics of thermal inertia in thermal systems, fully utilizing and exploiting the thermal inertia of integrated energy systems can enhance the flexibility of power system operation and ensure its reliability and security.

[0004] While research has been conducted on improving the operational flexibility of integrated energy systems by leveraging the thermal inertia characteristics of thermal systems, there is a lack of study on integrated frequency regulation strategies and methods for both integrated energy and power systems. Existing research primarily focuses on the coordinated optimization of various subsystems within integrated energy systems, neglecting to fully utilize the thermal inertia of thermal systems to enhance system frequency regulation power reserves. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for optimizing the operation of an electrothermal coupled integrated energy system, which optimizes the frequency regulation power of the power system based on thermal inertia to improve the utilization efficiency of integrated energy.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A method for optimizing the operation of an electrothermal coupled integrated energy system, the method comprising:

[0008] Obtain measured data sets of an electrothermal coupled integrated energy system; the electrothermal coupled integrated energy system includes a power system, a thermal system, an energy storage system, a heat dissipation system, and an energy transmission system; the power system includes thermal power units, combined heat and power units, wind power units, and photovoltaic power plants; the thermal system includes electric boilers, heat exchange stations, and heating networks;

[0009] The minimum inertia requirement of the power system is determined based on the measured dataset, and then a real-time inertia constraint is established based on the minimum inertia requirement.

[0010] Based on the measured dataset, system operating power balance constraints, system equipment output limit constraints, system equipment operating limit constraints, and heating terminal indoor temperature constraints are established respectively.

[0011] Based on the real-time inertia constraint, the system operating power balance constraint, the system equipment output limit constraint, the system equipment operating limit constraint, and the indoor temperature constraint of the heating terminal, a frequency regulation strategy model for the electric heating system is established with the goal of minimizing the operating cost of the electric-thermal coupled integrated energy system.

[0012] Solve the frequency regulation strategy model of the electric heating system to obtain the optimal frequency regulation result of the power system;

[0013] Based on the measured dataset, calculate the current minimum inertia requirement and the current system inertia.

[0014] When the current inertia of the system is less than the current minimum inertia requirement, the frequency of the power system is adjusted according to the optimal frequency adjustment result until the frequency data of the power system after frequency adjustment meets the preset frequency range, and then the frequency adjustment is terminated.

[0015] Optionally, the measured dataset includes the current rotational kinetic energy of the thermal power unit, the rotor kinetic energy of the wind turbine unit based on virtual inertia, the energy provided by the energy storage system based on virtual inertia, the energy provided by the load frequency response, the total capacity of the power system, and the current power disturbance value of the power system.

[0016] The virtual inertia is determined based on the thermal inertia model of the heat source, the thermal inertia model of the heat network, and the thermal inertia model of the heat load of the thermal system.

[0017] Based on the measured dataset, the current minimum inertia requirement and the current system inertia are calculated, specifically including:

[0018] Calculate the current minimum inertia requirement based on the current power disturbance value and the preset frequency change rate of the power system;

[0019] The current inertia of the system is calculated based on the current rotational kinetic energy of the thermal power unit, the rotor kinetic energy provided by the wind turbine unit based on virtual inertia, the energy provided by the energy storage system based on virtual inertia, the energy provided by the load frequency response, and the total capacity of the power system.

[0020] An operation optimization system for an electrothermal coupled integrated energy system, the system comprising:

[0021] The dataset acquisition module is used to acquire the measured dataset of the electrothermal coupled integrated energy system; the electrothermal coupled integrated energy system includes a power system, a thermal system, an energy storage system, a heat dissipation system, and an energy transmission system; the power system includes thermal power units, combined heat and power units, wind power units, and photovoltaic power plants; the thermal system includes electric boilers, heat exchange stations, and heating networks;

[0022] An inertia constraint construction module is used to determine the minimum inertia requirement of the power system based on the measured dataset, and then establish real-time inertia constraints according to the minimum inertia requirement.

[0023] The constraint establishment module is used to establish system operating power balance constraints, system equipment output limit constraints, system equipment operating limit constraints, and heating terminal indoor temperature constraints based on the measured dataset.

[0024] The frequency regulation optimization model construction module is used to establish a frequency regulation strategy model for the electric heating system based on the real-time inertia constraint, the system operating power balance constraint, the system equipment output limit constraint, the system equipment operating limit constraint, and the indoor temperature constraint of the heating terminal, with the goal of minimizing the operating cost of the electric heating coupled integrated energy system.

[0025] The model solving module is used to solve the frequency regulation strategy model of the electric heating system to obtain the optimal frequency regulation result of the power system;

[0026] The inertia calculation module is used to calculate the current minimum inertia requirement and the current system inertia based on the measured dataset.

[0027] The system frequency regulation module is used to regulate the frequency of the power system according to the optimal frequency regulation result when the current inertia of the system is less than the current minimum inertia requirement value, until the frequency data of the power system after frequency regulation meets the preset frequency range, and then exit the frequency regulation.

[0028] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0029] This invention discloses a method and system for optimizing the operation of an electrothermal coupled integrated energy system. Participating in primary frequency regulation of the power system, the method determines the minimum inertia requirement of the power system based on measured data, and then establishes real-time inertia constraints. Combining system operating power balance constraints, system equipment output limit constraints, system equipment operating limit constraints, and indoor temperature constraints at heating terminals, a frequency regulation strategy model for the electrothermal coupled integrated energy system is established with the goal of minimizing the operating cost of the system. The optimal configuration scheme for the frequency regulation power output of each frequency regulation resource is obtained by solving the model. Then, the current minimum inertia requirement and the current inertia of the electrothermal coupled integrated energy system are calculated and compared. When the current inertia of the system is less than the current minimum inertia requirement, frequency regulation of the power system is performed based on the optimal frequency regulation result until the frequency data of the power system after frequency regulation meets the preset frequency range, at which point frequency regulation is terminated, thus completing a full frequency regulation process and optimizing the operation of the electrothermal coupled integrated energy system. In this invention, the minimum inertia requirement of the power system is calculated using measured data and incorporated into the construction of the frequency regulation strategy model of the electric heating system. This realizes the optimization of the operation of the integrated energy system based on the thermal inertia of the thermal system, which can effectively promote the utilization of new energy sources (wind and solar). Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a flowchart illustrating the operation optimization method for the electrothermal coupled integrated energy system of the present invention;

[0032] Figure 2 This is a schematic diagram of the operation optimization system of the electrothermal coupling integrated energy system of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention provides a method and system for optimizing the operation of an electrothermal coupled integrated energy system, which participates in the primary frequency regulation of the power system, can improve the frequency response capability of a high-proportion renewable energy power system, and effectively promote the utilization of renewable energy.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Example 1

[0037] like Figure 1 As shown, this invention proposes an operation optimization method for an electrothermal coupled integrated energy system, comprising:

[0038] Step 100: Obtain the measured dataset of the electrothermal coupled integrated energy system; the electrothermal coupled integrated energy system includes a power system, a thermal system, an energy storage system, a heat dissipation system, and an energy transmission system; the power system includes thermal power units, combined heat and power units, wind power units, and photovoltaic power plants; the thermal system includes electric boilers, heat exchange stations, and heating networks. Specifically, the measured dataset is obtained from the database of the power system dispatch center.

[0039] The measured dataset includes the current rotational kinetic energy of thermal power units, the rotor kinetic energy of wind turbine units based on virtual inertia, the energy provided by energy storage systems based on virtual inertia, the energy provided by load frequency response, the total capacity of the power system, and the current power disturbance value of the power system.

[0040] The virtual inertia is determined based on the thermal inertia model of the heat source, the thermal inertia model of the heat network, and the thermal inertia model of the heat load of the thermal system.

[0041] When the heat source is an electric boiler, the thermal inertia model of the heat source in the thermal system is as follows:

[0042]

[0043] In the formula, c HS For the total specific heat capacity of the electric boiler, T HS Q represents the temperature of the medium in the electric boiler. E The input electrical power for the electric boiler, Q H For the output heat power of the electric boiler, u ha T represents the thermal conductivity of the electric boiler and air. h The ambient temperature around the electric boiler. This indicates the rate of change of the medium temperature in the electric boiler.

[0044] The thermal inertia model of a heating network includes a thermal delay model and a thermal loss model, wherein the thermal delay model is as follows:

[0045]

[0046] In the formula, k d Where L is the thermal delay coefficient, L is the length of the heating network pipe, v is the flow velocity of the heating network medium, and T is the thermal delay coefficient. d This is the thermal delay time.

[0047] The heat loss model is as follows:

[0048] ΔT=T s -T e =k loss (T s -T ha )

[0049] In the formula, ΔT represents the temperature deviation, T s T represents the inlet temperature of the pipe. e T represents the outlet terminal temperature of the pipeline. ha For the ambient temperature, k loss The heat dissipation coefficient of the pipe is as follows:

[0050]

[0051] In the formula, λ is the heat transfer efficiency, and c p Let m be the specific heat capacity of the medium in the pipeline, m be the flow rate and mass of the medium, and L be the length of the pipeline.

[0052] The thermal inertia model of heat load is as follows:

[0053]

[0054] In the formula, c M T represents the total specific heat capacity of the terminal heating system. in Q represents the indoor temperature of the terminal heating system. R Q represents the total heat dissipation power of the terminal heating system. L The total heat loss power of the terminal heating system. This represents the rate of change of indoor temperature in the terminal heating system. Among them,

[0055] Q R =∑Q r

[0056] Q r =Mc p (T rin -T in )

[0057] Q L =Aμ(T in -T out )

[0058] In the formula, M is the mass flow rate of the water supplied to the radiator, and T is the mass flow rate of the water supplied rin T represents the water supply temperature to the radiator. in For indoor temperature, c p The specific heat capacity of the water supplied to the radiator, Q r This represents the thermal power of the r-th radiator. A is the heating area, μ is the heat loss coefficient, and T is the thermal power of the radiator. outThis refers to the outdoor temperature.

[0059] The difference equation for the thermal inertia of the heating area, i.e., the thermal load thermal inertia model, is as follows:

[0060]

[0061] In the formula, c′ is the specific heat capacity per unit heating area, and ΔT is the scheduling time interval.

[0062] The rate of change of the electric boiler medium temperature is determined based on the heat source thermal inertia model of the thermal system; the thermal delay time and temperature deviation are determined based on the heating network thermal inertia model; and the rate of change of the indoor temperature of the terminal heating system is determined based on the heat load thermal inertia model. These three sets of data are used to evaluate the thermal inertia level of the entire electrothermal coupled integrated energy system. Based on the temperature constraints in the thermal system, and considering the heat power of the heat source, heating network, and heat load, since the heat source in this invention is an electric boiler and all heat power originates from electric power, the electric power can be adjusted by regulating the heat power. Therefore, ΔQ is defined. f The frequency-regulating power provided to the thermal system is an adjustable quantity. It is adjusted based on the temperature data obtained from the three inertial models mentioned above, ensuring that it does not exceed the thermal power provided by the heating network. The virtual inertia of the thermal system is then determined using the following formula:

[0063]

[0064] In the formula, H h This represents the virtual inertia of the thermal system.

[0065] Then, the virtual inertia of the thermal system is input into the electrothermal coupled integrated energy system, and the feedback data of the electrothermal coupled integrated energy system on the above virtual inertia is obtained through the power system dispatch center: the rotor kinetic energy provided by the wind turbine based on the virtual inertia, the energy provided by the energy storage system based on the virtual inertia, and the energy provided by the load frequency response, which prepares for the calculation of the current inertia of the system in step 600 below.

[0066] Step 200: Determine the minimum inertia requirement of the power system based on the measured dataset, and then establish real-time inertia constraints according to the minimum inertia requirement.

[0067] The formula for calculating the minimum inertia requirement is as follows:

[0068]

[0069] Among them, H min This represents the current minimum inertia requirement, and ΔP represents the current power disturbance value of the power system. This indicates the preset frequency change rate. This represents the initial rate of change of the per-unit value of the frequency deviation.

[0070] Regarding the rate of frequency change, the Chinese power grid has not made explicit requirements, only specifying the maximum frequency deviation. With the increasing electronic integration of power systems, the rate of frequency change cannot be ignored. In this invention, the disturbance power is taken as 10% of the load power during normal operation. Considering the significant weakening of the power system's inertia under high-proportion renewable energy integration, the rate of frequency change is taken as 2Hz / s. Therefore, the power system obtains its minimum inertia requirement in real time.

[0071] Step 300: Based on the measured dataset, establish system operating power balance constraints, system equipment output limit constraints, system equipment operating limit constraints, and heating terminal indoor temperature constraints, respectively.

[0072] Specifically, the system operating power balance constraints include electrical power balance constraints, thermal power balance constraints, and heat exchange constraints.

[0073] The power balance constraint is:

[0074] P G (t)+P CHP (t)+P WF (t)+P PV (t)+P ESD (t)=P L (t)+P ESC (t)+ΔP(t)

[0075] Among them, P G (t) represents the output power of the thermal power unit, P CHP (t) represents the output power of the combined heat and power unit, P WF (t) represents the theoretical output power of the wind farm, P PV (t) represents the theoretical output power of the photovoltaic power station, P ESD (t) represents the discharge power of the energy storage system equipment, P L (t) represents the theoretical output power of the energy transfer system, P ESC ΔP(t) represents the charging power of the energy storage system, and ΔP(t) represents the power loss of the power grid in the power system.

[0076] The thermal power balance constraint is:

[0077] Q CHP (t)+Q EB (t)=Q R (t)+ΔQ(t)

[0078] Among them, Q CHP (t) represents the output thermal power of the combined heat and power unit, Q. EB Q(t) represents the output heat power of the electric boiler, and ΔQ(t) represents the total heat power loss of the thermal system.R (t) represents the total heat dissipation power of the heating terminal.

[0079] The heat exchange constraint is:

[0080] Q HEX (t)=w[T HEX,sup (t)-T HEX,back (t)]

[0081] Among them, Q HEX (t) represents the input heat power of the heat exchange station, T HEX,sup (t) and T HEX,back (t) represents the primary network supply water temperature and return water temperature of the heat exchange station, respectively, and w is the heat equivalent value of the heat network flow rate.

[0082] The system equipment output limits include output limits for thermal power units, electrical output limits for combined heat and power (CHP) units, output limits for wind turbine units, output limits for photovoltaic power plants, thermal output limits for CHP units, thermal output limits for electric boilers, output limits for energy storage systems, and heating network constraints.

[0083] The real-time inertia constraint is:

[0084] Hs(t)≥H min (t)

[0085] Where Hs(t) represents the system inertia at time t, H min (t) represents the minimum inertia requirement.

[0086] The output limit constraints for thermal power units, combined heat and power units, wind turbine units, and photovoltaic power plants are as follows:

[0087]

[0088] Among them, P Gi,min P represents the lower limit of the output power of a thermal power unit. Gi,t P represents the current output power of the thermal power unit. Gi,max P represents the upper limit of the output power of a thermal power unit. CHPi,min P represents the lower limit of the output electrical power of a combined heat and power (CHP) unit. CHPi,t P represents the current output electrical power of the combined heat and power unit. CHPi,max P represents the upper limit of the output electrical power of a combined heat and power (CHP) unit. WFi,t P represents the current output power of the wind turbine. WFi,max P represents the upper limit of the wind turbine's output power. PVi,t P represents the current output power of the photovoltaic power station. PVi,max This indicates the upper limit of the output power of a photovoltaic power plant.

[0089] The thermal output limit constraint for combined heat and power units is:

[0090] Q CHPi,min ≤Q CHPi,t ≤Q CHPi,max

[0091] Among them, Q CHPi,min Q represents the lower limit of the output thermal power of a combined heat and power unit. CHPi,t Q represents the current output thermal power of the combined heat and power unit. CHPi,max This is the upper limit of the output thermal power of a combined heat and power unit.

[0092] The thermal output constraint of the electric boiler is:

[0093] 0≤Q EBi,t ≤Q EBi,max

[0094] Among them, Q EBi,t Q represents the current output thermal power of the electric boiler. EBi,max This is the upper limit of the output heat power of the electric boiler.

[0095] Energy storage system output limit constraints:

[0096] P b,min ≤P bi,t ≤P b,max

[0097] Among them, P b,min P represents the lower limit of the energy storage system's output. bi,t P represents the current output value of the energy storage system. b,max This indicates the upper limit of the energy storage system's output.

[0098] The constraints of the heating network are:

[0099]

[0100] Among them, T imin T represents the lower limit of the heating network temperature. i,(t) This indicates the current temperature of the heating network, T. imax Indicates the upper limit of the heating network temperature, m imin This represents the lower limit of the mass flow rate of the medium within the heating network, expressed in m. i,(t) Indicates the current medium flow rate and quality within the heating network, m imax Q represents the upper limit of the mass flow rate of the medium within the heating network. i (t) represents the output thermal power of the heating network, c represents the specific heat capacity of the medium inside the heating network, and m i T represents the flow rate and quality of the medium within the heating network. isup(t) T represents the temperature at which the medium flows into the heating network. iback(t) This indicates the temperature at which the medium flows out of the heating network.

[0101] The system equipment operation limit constraints include electric boiler power consumption constraints, thermal power unit output power ramping speed constraints, combined heat and power unit output heat power ramping rate constraints, combined heat and power unit output electrical power ramping rate constraints, power system node voltage limit constraints, and power system transmission line transmission power constraints.

[0102] The power consumption constraint for electric boilers is:

[0103] 0≤P EBi,t ≤P EBi,max

[0104] Among them, P EBi,t P represents the current power consumption of the electric boiler. EBi,max This represents the upper limit of the power consumption of an electric boiler.

[0105] The ramp-up rate constraints for the output power of thermal power units, the ramp-up rate constraints for the output electrical power of combined heat and power (CHP) units, and the ramp-up rate constraints for the output thermal power of CHP units are as follows:

[0106]

[0107] in, This represents the lower limit of the output power of the thermal power unit under the ramp rate constraint, where ΔT represents the dispatching time period. This represents the output power of the thermal power unit at time t+1. This represents the output power of the thermal power unit at time t. This represents the upper limit of the output power of a thermal power unit under the constraint of the ramp rate. This represents the lower limit of the output electrical power of a combined heat and power (CHP) unit under the ramp rate constraint. This represents the output electrical power of the combined heat and power unit at time t+1. This represents the output electrical power of the combined heat and power unit at time t. This represents the upper limit of the output electrical power of a combined heat and power unit under the ramp rate constraint. This represents the lower limit of the output thermal power of a combined heat and power unit under the ramp rate constraint. This represents the output thermal power of the cogeneration unit at time t+1. This represents the output thermal power of the combined heat and power unit at time t. This represents the upper limit of the output thermal power of a combined heat and power unit under the constraint of ramp rate.

[0108] The voltage limit constraints for power system nodes are as follows:

[0109] U i,min ≤U i,t ≤U i,max

[0110] Among them, U i,min U represents the lower limit of the node voltage. i,t U represents the current value of the node voltage. i,max This indicates the upper limit of the node voltage.

[0111] The power transmission capacity constraint of power system transmission lines is:

[0112] |P ij,t |≤P ij,max

[0113] Among them, P ij,t P represents the current transmission power of the power system's transmission lines. ij,max This indicates the upper limit of the power transmission capacity of power system transmission lines.

[0114] The indoor temperature constraint for heating terminals is:

[0115] T inimin ≤T ini (t)≤T inimax

[0116] Among them, T inimin T represents the lower limit of indoor temperature at the heating terminal. ini (t) represents the current indoor temperature value of the heating terminal, T inimax This indicates the upper limit of the indoor temperature at the heating terminal.

[0117] Step 400: Based on the real-time inertia constraint, the system operating power balance constraint, the system equipment output limit constraint, the system equipment operating limit constraint, and the indoor temperature constraint of the heating terminal, a frequency regulation strategy model for the electric heating system is established with the goal of minimizing the operating cost of the electric-thermal coupled integrated energy system.

[0118] The objective of minimizing the operating cost of the electrothermal coupled integrated energy system specifically includes: according to the formula

[0119]

[0120] Establish the objective function; where,

[0121]

[0122]

[0123] C WF (t)=c WF [P WFP (t)-P WFR (t)];

[0124] C PV (t)=cPV [P PVP (t)-P PVR (t)];

[0125] C L (t)=c L P Loss (t);

[0126] C R (t)=c R Q R (t);

[0127] minf represents the minimum operating cost of the electrothermal coupled integrated energy system, T represents the operating cycle, and C represents the minimum operating cost. G (t) represents the operating cost of the thermal power unit, C CHP (t) represents the operating cost of the combined heat and power unit, C WF (t) represents the operating cost of the wind turbine, C PV (t) represents the operating cost of the photovoltaic power plant, C L (t) represents the cost of the energy transmission system, C R (t) represents the operating cost of the cooling system; c c P represents the market price of coal, a, b, and c represent the operating cost coefficients of thermal power units, and P represents the market price of coal. G (t) represents the output power of the thermal power unit, P CHP (t) represents the output power of the cogeneration unit, B represents the steam output of the cogeneration unit, α0, α1, α2, α3, α4, and α5 represent the operating cost coefficients of the cogeneration unit, and c WF P represents the cost of wind curtailment penalty for wind turbines. WFP (t) represents the reported power of the wind turbine, P WFR (t) represents the actual output power of the wind turbine, c PV P represents the cost of curtailment penalties for photovoltaic power plants. PVP (t) represents the reported power of the photovoltaic power station, P PVR (t) represents the actual output power of the photovoltaic power station, c L P represents the unit cost of energy transmission. Loss (t) represents the transmission loss power, c R Q represents the heat dissipation cost coefficient of the heat dissipation system. R (t) represents the total heat dissipation power of the heating terminal.

[0128] Step 500: Solve the frequency regulation strategy model of the electric heating system to obtain the optimal frequency regulation result of the power system, that is, obtain the optimal configuration scheme of frequency regulation power reserve for the cogeneration unit and electric boiler in the thermal system, so as to realize that the thermal system can use its own thermal inertia to provide sufficient inertia support for the power system.

[0129] Furthermore, a particle swarm optimization algorithm is used to solve the problem and obtain an optimized configuration scheme for the backup power of the electrothermal coupled integrated energy system participating in system frequency regulation.

[0130] Step 600: Based on the measured dataset, calculate the current minimum inertia requirement and the current system inertia.

[0131] Step 600 specifically includes:

[0132] 1) Calculate the current minimum inertia requirement based on the current power disturbance value and the preset frequency change rate of the power system; see above for details.

[0133] 2) Calculate the current inertia of the system based on the current rotational kinetic energy of the thermal power unit, the rotor kinetic energy provided by the wind turbine unit based on virtual inertia, the energy provided by the energy storage system based on virtual inertia, the energy provided by the load frequency response, and the total capacity of the power system.

[0134] Specifically, the formula for calculating the current inertia of the system is:

[0135]

[0136] Among them, H S E represents the current inertia of the system. G E represents the current rotational kinetic energy of the thermal power unit. WF E represents the rotor kinetic energy provided by the wind turbine based on virtual inertia. ES E represents the energy provided by the energy storage system based on virtual inertia. L This represents the energy provided by the load frequency response, and S represents the total capacity of the power system.

[0137] Step 700: When the current inertia of the system is less than the current minimum inertia requirement, the power system is frequency regulated according to the optimal frequency regulation result. The frequency regulation command is sent from the power system dispatch center to the dispatch center of the electric boiler plant and the dispatch center of the thermal power plant. When the electric boiler plant and the thermal power plant receive the frequency regulation command, they immediately start the frequency regulation power and participate in the system frequency regulation. Frequency regulation is terminated when the frequency data of the power system after frequency regulation meets the preset frequency range.

[0138] Specifically, the frequency regulation power output of electric boilers and cogeneration units should be flexibly adjusted based on the real-time detection of frequency change rate and frequency deviation by the power system dispatch center. When the detected system frequency change rate and frequency deviation meet the requirements for normal power system operation, the power system dispatch center sends a command to cause the electric boilers and cogeneration units to exit frequency regulation mode. Furthermore, because the frequency regulation power output of electric boilers and cogeneration units responds quickly, this invention employs direct communication between the power system dispatch center and the frequency control systems of the electric boilers and cogeneration units, enabling the thermal system to respond to frequency changes in real time and ensuring the frequency stability of the power system under fault disturbances.

[0139] When the current inertia of the system is greater than or equal to the current minimum inertia requirement, frequency modulation is terminated. This invention ensures that the system has sufficient frequency modulation reserve power, which can meet the frequency stability requirements of the system under power disturbances.

[0140] Furthermore, the method of the present invention also includes:

[0141] Step 800: After exiting frequency regulation, based on the real-time inertia constraint, the system operating power balance constraint, the system equipment output limit constraint, the system equipment operating limit constraint, and the indoor temperature constraint of the heating terminal, an electric heating system control recovery optimization model is established with the goal of minimizing the operating cost of the thermal power unit and the cogeneration unit.

[0142] Specifically, considering the real-time operating conditions of wind and solar power systems, as well as real-time data on electrical and thermal loads, and taking into account wind and solar forecast data and forecast data on electrical and thermal loads, combined with real-time ambient temperature, a control scheme for restoring the heating power of the thermal system is determined. That is:

[0143] With the goal of minimizing the operating costs of the thermal power unit and the combined heat and power unit, and constrained by the operational balance of the electric heating system and equipment limitations (consistent with the constraints established in step 300 above), an optimization model for the control recovery of the electric heating system is established. The objective function of the optimization model in the electric heating system control recovery optimization model is:

[0144]

[0145] Step 900: Solve the control recovery optimization model of the electric heating system to obtain the optimized recovery frequency modulation result; the optimized recovery frequency modulation result is used to restore the heating power of the heating system, realize the flexible recovery control of the heating power of the heating system, effectively avoid the problem of secondary frequency drop in the system caused by power recovery control, and at the same time ensure the energy reliability of users.

[0146] Furthermore, in a specific practical application, if a power system fault occurs, that is, when the frequency change rate and frequency deviation detected by the power system dispatch center in real time exceed the set threshold, the power system dispatch center will directly send the frequency regulation start signal to the frequency regulation control system of the thermal power unit and electric boiler in the thermal power system, quickly start the frequency regulation power, suppress the frequency change rate, reduce the maximum frequency deviation, and thus ensure the frequency stability of the power system even under fault conditions.

[0147] In summary, the method provided in this embodiment allows the power system dispatch center to assess the system's minimum inertia requirement in real time during normal operation and configure system inertia reserves, i.e., frequency regulation power reserves, based on the minimum inertia requirement to provide frequency response capability. During fault phases, when the frequency change rate exceeds a set threshold, the frequency regulation power of the thermal system is rapidly activated to suppress the power system's frequency change rate and maximum frequency deviation. After frequency regulation ends, the power system dispatch center, combining the operating conditions of wind power and photovoltaic power generation with electrical and thermal load data, aims to minimize the operating cost of synchronous generator units and, constrained by the system's minimum inertia requirement, orderly restores the heating power of the heating system to meet the load's heating demand. This invention can improve the frequency stability of the system caused by low inertia due to a high proportion of new energy access, ensuring the frequency stability of the power system in both normal and fault states.

[0148] Example 2

[0149] like Figure 2 As shown, in order to achieve the technical solution as described in Embodiment 1, this embodiment provides an electrothermal coupling integrated energy system operation optimization system, including:

[0150] The dataset acquisition module 101 is used to acquire the measured dataset of the electrothermal coupled integrated energy system; the electrothermal coupled integrated energy system includes a power system, a thermal system, an energy storage system, a heat dissipation system, and an energy transmission system; the power system includes thermal power units, cogeneration units, wind power units, and photovoltaic power plants; the thermal system includes electric boilers, heat exchange stations, and heating networks.

[0151] The inertia constraint construction module 201 is used to determine the minimum inertia requirement of the power system based on the measured dataset, and then establish real-time inertia constraints according to the minimum inertia requirement.

[0152] The constraint establishment module 301 is used to establish system operating power balance constraints, system equipment output limit constraints, system equipment operating limit constraints, and heating terminal indoor temperature constraints based on the measured dataset.

[0153] The frequency regulation optimization model construction module 401 is used to establish a frequency regulation strategy model for the electric heating system based on the real-time inertia constraint, the system operating power balance constraint, the system equipment output limit constraint, the system equipment operating limit constraint, and the indoor temperature constraint of the heating terminal, with the goal of minimizing the operating cost of the electric heating coupled integrated energy system.

[0154] The model solving module 501 is used to solve the frequency regulation strategy model of the electric heating system to obtain the optimal frequency regulation result of the power system.

[0155] The inertia calculation module 601 is used to calculate the current minimum inertia requirement and the current system inertia based on the measured dataset.

[0156] The system frequency regulation module 701 is used to regulate the frequency of the power system according to the optimal frequency regulation result when the current inertia of the system is less than the current minimum inertia requirement value, until the frequency data of the power system after frequency regulation meets the preset frequency range, and then exit the frequency regulation.

[0157] Compared with the prior art, the present invention also has the following advantages:

[0158] (1) This invention comprehensively considers the inherent inertia of the heat source, heat network, and heat load in the thermal system of the integrated energy system, combined with the inherent inertia of the synchronous generator in the power system, the frequency response of the load itself, the virtual inertia of the wind turbine generator set, and the virtual inertia of the energy storage device, to reserve the system's frequency regulation power in real time and ensure sufficient inertia level of the system. Then, under the premise of ensuring the stability of the power system frequency, it can realize the high proportion, large scale, and wide range of local consumption and utilization of new energy, which can improve the economic efficiency of the entire system. Under the action of the thermal inertia of the thermal system, the configuration capacity of the energy storage device in the power system can be reduced, thereby reducing the investment and construction cost of the power system, which is of great significance.

[0159] In integrated energy systems, the thermal inertia of the thermal system and the virtual inertia control of energy storage systems and wind turbine generators are crucial, while the inherent inertia of thermal power units and loads is fully considered in the real-time inertia calculation of the power system. Due to the large thermal inertia of the thermal system, it plays a positive role in rapid frequency regulation, especially primary frequency regulation of the power system. The larger the thermal storage capacity of the thermal system, the greater the power stored in the medium in the pipeline network, and the greater the power of the heat load, the stronger its ability to participate in system frequency regulation.

[0160] (2) This invention is easy to implement. Through the coordinated and optimized operation of the power system and the integrated energy system, it can compensate for the reduced inertia caused by a high proportion of new energy sources being connected to the power system. This invention has a clear concept, a simple implementation plan, and great engineering value.

[0161] (3) When the power recovery control of the thermal system is implemented, the flexible recovery control of the heating power of the thermal system is realized, which effectively avoids the problem of secondary frequency drop of the system caused by power recovery control.

[0162] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0163] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for optimizing the operation of an electrothermal coupled integrated energy system, characterized in that the method... include: Obtain the measured dataset of the electrothermal coupled integrated energy system; The electrothermal coupled integrated energy system includes a power system, a thermal system, an energy storage system, a heat dissipation system, and an energy transmission system; the power system includes thermal power units, combined heat and power units, wind power units, and photovoltaic power plants; the thermal system includes electric boilers, heat exchange stations, and heating networks. The minimum inertia requirement of the power system is determined based on the measured dataset, and then a real-time inertia constraint is established based on the minimum inertia requirement. Based on the measured dataset, system operating power balance constraints, system equipment output limit constraints, system equipment operating limit constraints, and heating terminal indoor temperature constraints are established respectively. Based on the real-time inertia constraint, the system operating power balance constraint, the system equipment output limit constraint, the system equipment operating limit constraint, and the indoor temperature constraint of the heating terminal, a frequency regulation strategy model for the electric heating system is established with the goal of minimizing the operating cost of the electric-thermal coupled integrated energy system. Solve the frequency regulation strategy model of the electric heating system to obtain the optimal frequency regulation result of the power system; Based on the measured dataset, calculate the current minimum inertia requirement and the current system inertia. When the current inertia of the system is less than the current minimum inertia requirement, the frequency of the power system is adjusted according to the optimal frequency adjustment result until the frequency data of the power system after frequency adjustment meets the preset frequency range, and then the frequency adjustment is terminated.

2. The method for optimizing the operation of an electrothermal coupled integrated energy system according to claim 1, characterized in that, The measured dataset includes the current rotational kinetic energy of thermal power units, the rotor kinetic energy of wind turbine units based on virtual inertia, the energy provided by energy storage systems based on virtual inertia, the energy provided by load frequency response, the total capacity of the power system, and the current power disturbance value of the power system. The virtual inertia is determined based on the thermal inertia model of the heat source, the thermal inertia model of the heat network, and the thermal inertia model of the heat load of the thermal system. Based on the measured dataset, the current minimum inertia requirement and the current system inertia are calculated, specifically including: Calculate the current minimum inertia requirement based on the current power disturbance value and the preset frequency change rate of the power system; The current inertia of the system is calculated based on the current rotational kinetic energy of the thermal power unit, the rotor kinetic energy provided by the wind turbine unit based on virtual inertia, the energy provided by the energy storage system based on virtual inertia, the energy provided by the load frequency response, and the total capacity of the power system.

3. The method for optimizing the operation of an electrothermal coupled integrated energy system according to claim 2, characterized in that, The formula for calculating the current minimum inertia requirement is as follows: Among them, H min This represents the current minimum inertia requirement, and ΔP represents the current power disturbance value of the power system. This indicates the preset frequency change rate.

4. The method for optimizing the operation of an electrothermal coupled integrated energy system according to claim 2, characterized in that, The formula for calculating the current inertia of the system is as follows: Among them, H S E represents the current inertia of the system. G E represents the current rotational kinetic energy of the thermal power unit. WF E represents the rotor kinetic energy provided by the wind turbine based on virtual inertia. ES E represents the energy provided by the energy storage system based on virtual inertia. L This represents the energy provided by the load frequency response, and S represents the total capacity of the power system.

5. The method for optimizing the operation of an electrothermal coupled integrated energy system according to claim 1, characterized in that, The objective of minimizing the operating cost of the aforementioned electrothermal coupled integrated energy system specifically includes: According to the formula Establish the objective function; where, C WF (t)=c WF [P WFP (t)-P WFR (t)]; C PV (t)=c PV [P PVP (t)-P PVR (t)]; C L (t)=c L P Loss (t); C R (t)=c R Q R (t); minf represents the minimum operating cost of the electrothermal coupled integrated energy system, T represents the operating cycle, and C represents the minimum operating cost. G (t) represents the operating cost of the thermal power unit, C CHP (t) represents the operating cost of the combined heat and power unit, C WF (t) represents the operating cost of the wind turbine, C PV (t) represents the operating cost of the photovoltaic power plant, C L (t) represents the cost of the energy transmission system, C R (t) represents the operating cost of the cooling system; c c P represents the market price of coal, a, b, and c represent the operating cost coefficients of thermal power units, and P represents the market price of coal. G (t) represents the output power of the thermal power unit, P CHP (t) represents the output power of the cogeneration unit, B represents the steam output of the cogeneration unit, α0, α1, α2, α3, α4, and α5 represent the operating cost coefficients of the cogeneration unit, and c WF P represents the cost of wind curtailment penalty for wind turbines. WFP (t) represents the reported power of the wind turbine, P WFR (t) represents the actual output power of the wind turbine, c PV P represents the cost of curtailment penalties for photovoltaic power plants. PVP (t) represents the reported power of the photovoltaic power station, P PVR (t) represents the actual output power of the photovoltaic power station, c L P represents the unit cost of energy transmission. Loss (t) represents the transmission loss power, c R Q represents the heat dissipation cost coefficient of the heat dissipation system. R (t) represents the total heat dissipation power of the heating terminal.

6. The method for optimizing the operation of an electrothermal coupled integrated energy system according to claim 1, characterized in that, The system operating power balance constraints include electrical power balance constraints, thermal power balance constraints, and heat exchange constraints. The system equipment output limit constraints include output limit constraints for thermal power units, electrical output limit constraints for combined heat and power units, output limit constraints for wind power units, output limit constraints for photovoltaic power stations, thermal output limit constraints for combined heat and power units, thermal output constraints for electric boilers, output limit constraints for energy storage systems, and heating network constraints. The system equipment operation limit constraints include electric boiler power consumption constraints, thermal power unit output power ramping speed constraints, combined heat and power unit output heat power ramping rate constraints, combined heat and power unit output electrical power ramping rate constraints, power system node voltage limit constraints, and power system transmission line transmission power constraints.

7. The method for optimizing the operation of an electrothermal coupled integrated energy system according to claim 6, characterized in that, The power balance constraint is: P G (t)+P CHP (t)+P WF (t)+P PV (t)+P ESD (t)=P L (t)+P ESC (t)+ΔP(t) Among them, P G (t) represents the output power of the thermal power unit, P CHP (t) represents the output power of the combined heat and power unit, P WF (t) represents the theoretical output power of the wind farm, P PV (t) represents the theoretical output power of the photovoltaic power station, P ESD (t) represents the discharge power of the energy storage system equipment, P L (t) represents the theoretical output power of the energy transfer system, P ESC (t) represents the charging power of the energy storage system, and ΔP(t) represents the power loss of the power grid in the power system; The thermal power balance constraint is: Q CHP (t)+Q EB (t)=Q R (t)+ΔQ(t) Among them, Q CHP (t) represents the output thermal power of the combined heat and power unit, Q. EB Q(t) represents the output heat power of the electric boiler, and ΔQ(t) represents the total heat power loss of the thermal system. R (t) represents the total heat dissipation power of the heating terminal; The heat exchange constraint is: Q HEX (t)=w[T HEX,sup (t)-T HEX,back (t)] Among them, Q HEX (t) represents the input heat power of the heat exchange station, T HEX,sup (t) and T HEX,back (t) represents the primary network supply water temperature and return water temperature of the heat exchange station, respectively, and w is the heat equivalent value of the heat network flow rate; The real-time inertia constraint is: Hs(t)≥H min (t) Where Hs(t) represents the system inertia at time t, H min (t) represents the minimum inertia requirement; The output limit constraints for thermal power units, combined heat and power units, wind turbine units, and photovoltaic power plants are as follows: Among them, P Gi,min P represents the lower limit of the output power of a thermal power unit. Gi,t P represents the current output power of the thermal power unit. Gi,max P represents the upper limit of the output power of a thermal power unit. CHPi,min P represents the lower limit of the output electrical power of a combined heat and power (CHP) unit. CHPi,t P represents the current output electrical power of the combined heat and power unit. CHPi,max P represents the upper limit of the output electrical power of a combined heat and power (CHP) unit. WFi,t P represents the current output power of the wind turbine. WFi,max P represents the upper limit of the wind turbine's output power. PVi,t P represents the current output power of the photovoltaic power station. PVi,max This indicates the upper limit of the output power of a photovoltaic power station; The thermal output limit constraint for combined heat and power units is: Q CHPi,min ≤Q CHPi,t ≤Q CHPi,max Among them, Q CHPi,min Q represents the lower limit of the output thermal power of a combined heat and power unit. CHPi,t Q represents the current output thermal power of the combined heat and power unit. CHPi,max This refers to the upper limit of the output thermal power of a combined heat and power unit; The thermal output constraint of the electric boiler is: 0≤Q EBi,t ≤Q EBi,max Among them, Q EBi,t Q represents the current output thermal power of the electric boiler. EBi,max This refers to the upper limit of the output heat power of the electric boiler; Energy storage system output limit constraints: P b,min ≤P bi,t ≤P b,max Among them, P b,min P represents the lower limit of the energy storage system's output. bi,t P represents the current output value of the energy storage system. b,max This indicates the upper limit of the energy storage system's output. The constraints of the heating network are: Among them, T imin T represents the lower limit of the heating network temperature. i,(t) This indicates the current temperature of the heating network, T. imax Indicates the upper limit of the heating network temperature, m imin This represents the lower limit of the mass flow rate of the medium within the heating network, expressed in m. i Indicates the current medium flow rate and quality within the heating network, m imax Q represents the upper limit of the mass flow rate of the medium within the heating network. i (t) represents the output thermal power of the heating network, c represents the specific heat capacity of the medium inside the heating network, and m i T represents the flow rate and quality of the medium within the heating network. isup(t) T represents the temperature at which the medium flows into the heating network. iback(t) Indicates the temperature at which the medium flows out of the heating network; The power consumption constraint for electric boilers is: 0≤P EBi,t ≤P EBi,max Among them, P EBi,t P represents the current power consumption of the electric boiler. EBi,max This refers to the upper limit of the power consumption of an electric boiler. The ramp-up rate constraints for the output power of thermal power units, the ramp-up rate constraints for the output electrical power of combined heat and power (CHP) units, and the ramp-up rate constraints for the output thermal power of CHP units are as follows: in, This represents the lower limit of the output power of the thermal power unit under the ramp rate constraint, where ΔT represents the dispatching time period. This represents the output power of the thermal power unit at time t+1. This represents the output power of the thermal power unit at time t. This represents the upper limit of the output power of a thermal power unit under the constraint of the ramp rate. This represents the lower limit of the output electrical power of a combined heat and power (CHP) unit under the ramp rate constraint. This represents the output electrical power of the combined heat and power unit at time t+1. This represents the output electrical power of the combined heat and power unit at time t. This represents the upper limit of the output electrical power of a combined heat and power unit under the ramp rate constraint. This represents the lower limit of the output thermal power of a combined heat and power unit under the ramp rate constraint. This represents the output thermal power of the cogeneration unit at time t+1. This represents the output thermal power of the combined heat and power unit at time t. This represents the upper limit of the output thermal power of a combined heat and power unit under the ramp rate constraint; The voltage limit constraints for power system nodes are as follows: IN i,min ≤U i,t ≤U i,max Among them, U i,min U represents the lower limit of the node voltage. i,t U represents the current value of the node voltage. i,max Indicates the upper limit of the node voltage; The power transmission capacity constraint of power system transmission lines is: |P ij,t |≤P ij,max Among them, P ij,t P represents the current transmission power of the power system's transmission lines. ij,max This indicates the upper limit of the power transmission capacity of power system transmission lines; The indoor temperature constraint for heating terminals is: T inimin ≤T ini (t)≤T inimax Among them, T inimin T represents the lower limit of indoor temperature at the heating terminal. ini (t) represents the current indoor temperature value of the heating terminal, T inimax This indicates the upper limit of the indoor temperature at the heating terminal.

8. The method for optimizing the operation of an electrothermal coupled integrated energy system according to claim 1, characterized in that, The method also includes: After frequency regulation is discontinued, based on the real-time inertia constraint, the system operating power balance constraint, the system equipment output limit constraint, the system equipment operating limit constraint, and the indoor temperature constraint of the heating terminal, an electric heating system control recovery optimization model is established with the goal of minimizing the operating cost of the thermal power unit and the cogeneration unit. The optimized recovery model of the electric heating system is solved to obtain the optimized recovery frequency modulation result; the optimized recovery frequency modulation result is used to restore the heating power of the heating system.

9. A system for optimizing the operation of an electrothermal coupled integrated energy system, characterized in that, The system includes: The dataset acquisition module is used to acquire the measured dataset of the electrothermal coupled integrated energy system; The electrothermal coupled integrated energy system includes a power system, a thermal system, an energy storage system, a heat dissipation system, and an energy transmission system; the power system includes thermal power units, combined heat and power units, wind power units, and photovoltaic power plants; the thermal system includes electric boilers, heat exchange stations, and heating networks. An inertia constraint construction module is used to determine the minimum inertia requirement of the power system based on the measured dataset, and then establish real-time inertia constraints according to the minimum inertia requirement. The constraint establishment module is used to establish system operating power balance constraints, system equipment output limit constraints, system equipment operating limit constraints, and heating terminal indoor temperature constraints based on the measured dataset. The frequency regulation optimization model construction module is used to establish a frequency regulation strategy model for the electric heating system based on the real-time inertia constraint, the system operating power balance constraint, the system equipment output limit constraint, the system equipment operating limit constraint, and the indoor temperature constraint of the heating terminal, with the goal of minimizing the operating cost of the electric heating coupled integrated energy system. The model solving module is used to solve the frequency regulation strategy model of the electric heating system to obtain the optimal frequency regulation result of the power system; The inertia calculation module is used to calculate the current minimum inertia requirement and the current system inertia based on the measured dataset. The system frequency regulation module is used to regulate the frequency of the power system according to the optimal frequency regulation result when the current inertia of the system is less than the current minimum inertia requirement value, until the frequency data of the power system after frequency regulation meets the preset frequency range, and then exit the frequency regulation.

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