Method and system for improving flexibility of novel power system in cold region based on heat supply network inertia

Abstract

The invention belongs to the technical field of electric heating joint optimization scheduling, and discloses a cold region novel power system flexibility improvement method and system based on heat supply network inertia, and the method comprises the steps: fusing the inertia characteristics of a heat supply network, building an electric heating cooperation model, and achieving the whole-cycle cost minimization solving and flexibility quantitative evaluation through the combination of multiple constraints, and a heat storage adjusting space is provided for the system according to the heat delay and heat loss characteristics of heat supply network inertia, the CHP unit is allowed to preferentially respond to power dispatching on the premise that heat supply stability is guaranteed, the straight condensing thermal power unit is allowed to adjust power supply and demand through climbing, a heat pump supplements a heat supply gap, and the flexible adjusting capacity of the system is greatly improved. The whole-cycle cost optimization target reduces unit operation and wind and light abandoning losses, multi-dimensional flexibility index quantification verifies the remarkable improvement effect of heat supply network inertia on the flexibility of a power grid, the stable operation capacity of a power system under high-proportion new energy access is enhanced, and the winter heat supply reliability of the cold region is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of electric and thermal joint optimization scheduling technology, and relates to a method and system for improving the flexibility of a new type of power system in cold regions based on the inertia of the heating network. Background Technology

[0002] In cold regions, due to complex climatic conditions, the output of new energy sources is significantly affected by meteorological factors, exhibiting strong randomness, volatility, and unpredictability, posing a considerable challenge to the safe and stable operation of the power system. Simultaneously, long and harsh winters lead to high demand for indoor heating. Combined heat and power (CHP) units are commonly used in cold-region power systems to handle heating, but these units are limited by heat load demand during the heating season, resulting in limited output adjustment space and difficulty in flexibly responding to the power system's dispatch needs. When new energy output increases while the power load remains relatively stable, CHP units are constrained by minimum heating output and cannot promptly reduce power generation, leading to problems such as wind and solar power curtailment, thus limiting the high-proportion integration of new energy. Existing research does not adequately consider the thermal inertia characteristics of cold-region heating systems and their supporting role in system flexibility. Therefore, there is an urgent need for an operation optimization method that can fully utilize the thermal inertia characteristics of the heating network and achieve coordinated regulation of electricity and heat to improve the flexibility of integrated energy systems in cold regions and enhance the system's stable operation under conditions of high-proportion new energy integration. Summary of the Invention

[0003] The purpose of this invention is to solve the problems in the prior art where the output adjustment space of CHP units during heating is limited, making it difficult to flexibly respond to the dispatching needs of the power system, and the power generation cannot be reduced in time due to the minimum heating output. The invention provides a new method and system for improving the flexibility of a cold region power system based on the inertia of the heating network.

[0004] To achieve the above objectives, the present invention employs the following technical solution: Methods for improving the flexibility of new power systems in cold regions based on heating network inertia include: Based on the typical structure of an integrated electric and thermal energy system in cold regions, the core components of the integrated electric and thermal energy system are identified; and data on the electrical load, thermal load, and new energy output required for the operation of the system are collected to form a standardized input dataset. Based on the obtained standardized input dataset, and by integrating the thermal inertia characteristics of the heating network, an electrothermal synergistic model characterizing the coupling relationship between the thermal system and the power system is constructed. With the goal of minimizing the full-cycle operating cost of the electrothermal synergy model, the operating parameters of the electrothermal synergy model are solved by combining the power system power balance, unit output limits and thermal system heat balance constraints. Based on the obtained optimal operating parameters, the net load and multi-dimensional flexibility indicators of the system are calculated, the overall regulation capability of the system is quantitatively analyzed, and the supporting effect of the heating network on the flexibility of the power grid is verified.

[0005] A further improvement of the present invention is that: Furthermore, the core components include a combined heat and power (CHP) unit, a heat pump, and a condensing thermal power unit. The CHP unit operates under extraction steam conditions, and its output electrical power and thermal power at time t satisfy the following relationship: The feasible operating range for a combined heat and power (CHP) plant is based on the output thermal power. The horizontal axis represents electrical power. The vertical axis represents the region formed by the corner points of the combined heat and power (CHP) plant, along with the horizontal and vertical axes. The electrothermal power coordinates of its corner points are as follows: The CHP unit operates under extraction steam conditions, and its output electrical power and output thermal power at time t satisfy the following relationship: ; And the combination coefficient Satisfy constraints: ; in, Let be the output electrical power of the i-th CHP unit at time t. Let be the output thermal power of the i-th CHP unit at time t. Let x and y be the x and y coordinates of the i-th CHP unit in the hotspot feasible region. The total number of CHP corner points of the i-th cogeneration unit.

[0006] Furthermore, the thermodynamic system portion of the electrothermal synergistic model includes a mass flow equation, which is: ; Meanwhile, the thermal system also includes heat exchange equations for heat source nodes, which satisfy the following: ; in, Let the mass flow rate be the mass flow rate from node j to node i. Let be the mass flow rate of hot water flowing from node i into node k. Each of these represents a set of pipes connected to node i, with node i as both the starting and ending point. The heat supplied by heat source node i at time t. The specific heat capacity of water, Let represent the mass flowing through heat source node i, and HS represent the set of heat source nodes. Let t represent the temperatures of heat source node i in the water supply pipe and the return pipe at time t, respectively.

[0007] Furthermore, the thermal system section also includes heat load heat exchange equations and supply and return water temperature constraints, wherein the heat load heat exchange equations satisfy: ; The supply and return water temperature constraints satisfy: ; in, Let be the heat absorbed by heat load node i at time t. Let be the mass flowing through load node i; L represents the set of heat load nodes. These are the lower and upper limits of the water supply temperature, respectively. These are the lower and upper limits of the return water temperature, respectively. The thermal inertia characteristics of the heating network are quantified by thermal delay and heat loss, which satisfy the following formula: ; In the formula, For the delay of pipe i during transmission, The density of water, Let i be the length of pipe i. Let i be the inner diameter of pipe i. Let i be the flow rate of pipe i; For pipe i after the delay, at time... The temperature of the hot water at the end of the pipe, Let be the temperature of the hot water at the beginning of pipe i during time period t. The temperature outside the pipe, This is the heat conversion coefficient per unit length of the pipe. Let be the flow rate of pipe i during time period t. For pipe i in t to Heat loss during the process.

[0008] Furthermore, the heat output and electrical power consumption of the heat pump at time t satisfy the following: ; in, Let be the heat output of the k-th heat pump at time t. Let be the electrical power consumed by the k-th heat pump at time t. Let be the electro-thermal efficiency of the k-th heat pump. This represents the upper limit of the heat output of the k-th heat pump; The ramp-up constraint for the CHP cogeneration unit is: ; in, These are the maximum downward and upward climbing rates of the i-th cogeneration unit, respectively; Let be the output electrical power of the i-th cogeneration unit at time t-1.

[0009] Furthermore, the objective of minimizing the total lifecycle operating cost of the electrothermal synergy model satisfies: ; Where F is the cost over the entire period, and T is the total number of time periods. Let be the cost of the i-th pure condensing thermal power unit at time t. This refers to the number of pure condensing thermal power units. The cost of the j-th CHP unit at time t, This refers to the number of CHP units. Let the cost of the k-th heat pump at time t be... For the number of heat pumps, This is a penalty for abandoning wind and light. The specific costs of each part are as follows: ; in, For the coefficient of pure condensing thermal power units, For the coefficients of the CHP unit, The coefficient of performance of the heat pump. The penalty coefficient for curtailing wind and solar power. Let be the electrical power output of condensing thermal power unit i at time t. Let be the electrical output and thermal output of the j-th CHP unit at time t, respectively. Let be the electrical power consumed by the k-th heat pump at time t. These represent the predicted and actual power output of wind farm i at time t, respectively. These represent the predicted and actual power output of photovoltaic power station i at time t, respectively. These are the numbers of wind farms and photovoltaic power plants, respectively. The constraints of pure condensing thermal power units are as follows: ; In the formula, These are the lower and upper limits of the output of pure condensing thermal power units, respectively. Let i represent the output of a pure condensing thermal power unit i at times t and t-1, respectively. These are the maximum rates of downward and upward climbing for pure condensing thermal power unit i, respectively. The power system power balance constraints are as follows: ; In the formula, Let be the magnitude of the load at time t; The heat balance expression for a thermodynamic system is as follows: ; In the formula, Let be the heat load at time t. Let be the heat loss of pipe i at time t. For the number of pipes, The change in heat stored in pipe i at time t is expressed as follows: ; In the formula, Consider delay for pipe i The stored heat power during the process from t-1 to t, Temperatures at the end of pipe i at times t and t-1, respectively; To ensure the stability of the heating network, the stored heat in one cycle is 0, specifically: In the formula, T represents the total number of time periods.

[0010] Furthermore, the system's net load and the flexibility of pure condensing thermal power units are met: The net load expression for the entire system is as follows: ; In the formula, Let be the net load at time t; The flexibility offered by pure condensing thermal power units is as follows: ; In the formula, These refer to the upward and downward flexible power supply of pure condensing thermal power units at time t. These are the upper and lower limits of the output of pure condensing thermal power units; The maximum upward and downward climbing speed of a pure condensing thermal power unit; For time intervals.

[0011] Furthermore, the multi-dimensional flexibility indicators also include the flexibility supply of CHP units and the total flexibility supply of the system; wherein the flexibility supply of CHP units is as follows: ; In the formula, These represent the upward and downward flexibility supply of the CHP unit at time t, respectively. These represent the maximum and minimum output of the CHP unit at time t, respectively; The flexibility provided by the integrated units is as follows: ; in, These are units that provide flexibility, offering both upward and downward flexibility.

[0012] Furthermore, the multi-dimensional flexibility index also includes the expected value (IRRE) of insufficient system ramping resources, satisfying: ; in, These are the up-adjustment and down-adjustment discrete cumulative distribution functions, respectively, used to characterize the distribution characteristics of the system's flexible adjustment capability at a given time scale; This represents the change in net load at time t. These are the net loads at times t and t-1, respectively. This indicates that time t is on a time scale of Changes in net load under the following conditions The time scales are respectively The upward and downward flexibility requirements due to changes in net load at time t; T is the total number of time periods. These represent the time period t and the time scale, respectively. The system adjusts the probability of insufficient ramp resources by increasing or decreasing them; its expression includes... This is used to describe the probabilistic situation where the supply of flexibility is just insufficient to cover the demand for changes in net load. Each within the entire cycle The system adjusts the expected value of insufficient ramp resources upwards and downwards over a time scale.

[0013] A new power system for cold regions based on the inertia of heating networks to enhance flexibility includes: The acquisition module, based on the typical structure of an integrated electric and thermal energy system in cold regions, identifies the core components of the integrated electric and thermal energy system; and collects the electrical load, thermal load, and new energy output data required for the operation of the system to form a standardized input dataset. The construction module, based on the acquired standardized input dataset, integrates the thermal inertia characteristics of the heating network to construct an electrothermal synergistic model characterizing the coupling relationship between the thermal system and the power system. The solution module aims to minimize the full-cycle operating cost of the electrothermal synergy model. It solves for the operating parameters of the electrothermal synergy model by combining the power system power balance, unit output limits, and thermal system heat balance constraints. The quantification module calculates the system's net load and multi-dimensional flexibility indicators based on the obtained optimal operating parameters, quantifies and analyzes the overall system regulation capability, and verifies the supporting effect of the heating network on the power grid's flexibility.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention establishes an electrothermal synergy model by integrating the inertial characteristics of the heating network. It combines multiple constraints to achieve full-cycle cost minimization and flexibility quantification. The thermal delay and heat loss characteristics of the heating network inertia provide the system with thermal storage and regulation space, allowing CHP units to prioritize power dispatch while ensuring stable heating. Pure condensing thermal power units supplement power supply and demand through ramp-up adjustments, while heat pumps fill heating gaps, significantly improving the system's flexible adjustment capabilities. The full-cycle cost optimization objective reduces unit operation and wind / solar curtailment losses. Multi-dimensional flexibility indicators quantify and verify the significant improvement effect of heating network inertia on grid flexibility. This enhances the stable operation capability of the power system under high-proportion renewable energy access while ensuring reliable heating in cold winters, combining technical practicality and economic rationality. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating the method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network, as described in this invention. Figure 2 This is a schematic diagram of the feasible operating domain of the combined heat and power (CHP) system of the present invention; Figure 3 A schematic diagram showing the electricity and heat loads and wind and solar power output data; Figure 4 This is a diagram illustrating the OSF flexibility index. Figure 5 This is a schematic diagram of the results for AFD+ and AFD-. Figure 6 A diagram illustrating the IRRE+ indicator; Figure 7 IRRE indicator diagram; Figure 8 This is a schematic diagram of the structure of the novel cold-region power system flexibility enhancement system based on heating network inertia according to the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0019] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0020] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0022] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0023] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 This invention discloses a method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network, comprising: S101, based on the typical structure of an integrated electric and thermal energy system in cold regions, identifies the core components of the integrated electric and thermal energy system; and collects the electrical load, thermal load, and new energy output data required for the operation of the system to form a standardized input dataset; The core components include a combined heat and power (CHP) unit, a heat pump, and a condensing thermal power unit. The condensing thermal power unit and the CHP unit are the core power generation units, respectively supplying electricity to the grid through autonomous output regulation and electrothermal coupling output, while renewable energy output serves as a supplement. The heat pump is a key power consumption unit, consuming grid electricity and converting it into heat energy; its power consumption is included in the electricity load side accounting. When renewable energy output fluctuates, the condensing thermal power unit quickly compensates through ramp-up regulation, the CHP unit adjusts its power generation output within the allowable heating range, and the heat pump can absorb excess grid electricity by adjusting its power consumption.

[0024] CHP (Combined Heat and Power) units are the basic heating units, directly inputting their heat generation into the heating network, and their heat generation is coupled with power generation. Heat pumps are supplementary heating units, generating heat by consuming electricity, and can fill the heating gap in the heating network when the heating capacity of CHP units is insufficient or when priority must be given to ensuring power generation flexibility. Pure condensing power units do not directly participate in heating, but indirectly create conditions for the heating operation of CHP units and heat pumps through power output regulation on the power side. With coordinated regulation of CHP units, heat pumps, and pure condensing power units, when CHP units are constrained by heating load, the thermal inertia of the heating network can temporarily store heat, allowing CHP units to prioritize power dispatch for a short period. At this time, heat pumps can compensate for heating fluctuations of CHP units by adjusting their power consumption, while pure condensing power units further balance power supply and demand through ramp-up regulation.

[0025] The combined heat and power (CHP) unit operates under extraction steam conditions, and its output electrical power and thermal power at time t satisfy the following relationship: See Figure 2 The feasible operating domain for a combined heat and power (CHP) plant is based on the output thermal power. The horizontal axis represents electrical power. The vertical axis represents the region formed by the corner points of the combined heat and power (CHP) plant, along with the horizontal and vertical axes. The electrothermal power coordinates of its corner points are as follows: The CHP unit operates under extraction steam conditions, and its output electrical power and output thermal power at time t satisfy the following relationship: ; And the combination coefficient Satisfy constraints: ; in, Let be the output electrical power of the i-th CHP unit at time t. Let be the output thermal power of the i-th CHP unit at time t. Let x and y be the x and y coordinates of the i-th CHP unit in the hotspot feasible region. The total number of CHP corner points of the i-th cogeneration unit.

[0026] S102, based on the obtained standardized input dataset, integrates the thermal inertia characteristics of the heating network to construct an electrothermal synergistic model characterizing the coupling relationship between the thermal system and the power system; The thermodynamic system portion of the electrothermal synergistic model includes a mass flow equation, which is: ; Meanwhile, the thermal system also includes heat exchange equations for heat source nodes, which satisfy the following: ; in, Let the mass flow rate be the mass flow rate from node j to node i. Let be the mass flow rate of hot water flowing from node i into node k. Each of these represents a set of pipes connected to node i, with node i as both the starting and ending point. The heat supplied by heat source node i at time t. The specific heat capacity of water, Let represent the mass flowing through heat source node i, and HS represent the set of heat source nodes. Let t represent the temperatures of heat source node i in the water supply pipe and the return pipe at time t, respectively.

[0027] The thermal system section also includes heat load heat exchange equations and supply and return water temperature constraints, wherein the heat load heat exchange equations satisfy: ; The supply and return water temperature constraints satisfy: ; in, Let be the heat absorbed by heat load node i at time t. Let be the mass flowing through load node i; L represents the set of heat load nodes. These are the lower and upper limits of the water supply temperature, respectively. These are the lower and upper limits of the return water temperature, respectively. The node mixing temperatures are as follows: ; In the formula, The temperature of the hot water at the end of the pipe during time period t. The temperature of the hot water at the beginning of pipe ik during time period t.

[0028] The thermal inertia characteristics of the heating network are quantified by thermal delay and heat loss, which satisfy the following formula: ; In the formula, For the delay of pipe i during transmission, The density of water, Let i be the length of pipe i. Let i be the inner diameter of pipe i. Let i be the flow rate of pipe i; For pipe i after the delay, at time... The temperature of the hot water at the end of the pipe, Let be the temperature of the hot water at the beginning of pipe i during time period t. The temperature outside the pipe, This is the heat conversion coefficient per unit length of the pipe. Let be the flow rate of pipe i during time period t. For pipe i in t to Heat loss during the process.

[0029] The heat pump's heat output and electrical power consumption at time t satisfy the following: ; in, Let be the heat output of the k-th heat pump at time t. Let be the electrical power consumed by the k-th heat pump at time t. Let be the electro-thermal efficiency of the k-th heat pump. This represents the upper limit of the heat output of the k-th heat pump; The ramp-up constraint for the CHP cogeneration unit is: ; in, These are the maximum downward and upward climbing rates of the i-th cogeneration unit, respectively; Let be the output electrical power of the i-th cogeneration unit at time t-1.

[0030] S103 aims to minimize the full-cycle operating cost of the electrothermal synergy model. It solves for the operating parameters of the electrothermal synergy model by combining the power system power balance, unit output limits, and thermal system heat balance constraints. The objective of minimizing the full-cycle operating cost of the electrothermal synergistic model is to satisfy: ; Where F is the cost over the entire period, and T is the total number of time periods. Let be the cost of the i-th pure condensing thermal power unit at time t. This refers to the number of pure condensing thermal power units. The cost of the j-th CHP unit at time t, This refers to the number of CHP units. Let the cost of the k-th heat pump at time t be... For the number of heat pumps, This is a penalty for abandoning wind and light. The specific costs of each part are as follows: ; in, For the coefficient of pure condensing thermal power units, For the coefficients of the CHP unit, The coefficient of performance of the heat pump. The penalty coefficient for curtailing wind and solar power. Let be the electrical power output of condensing thermal power unit i at time t. Let be the electrical output and thermal output of the j-th CHP unit at time t, respectively. Let be the electrical power consumed by the k-th heat pump at time t. These represent the predicted and actual power output of wind farm i at time t, respectively. These represent the predicted and actual power output of photovoltaic power station i at time t, respectively. These are the numbers of wind farms and photovoltaic power plants, respectively. The constraints of pure condensing thermal power units are as follows: ; In the formula, These are the lower and upper limits of the output of pure condensing thermal power units, respectively. Let i represent the output of a pure condensing thermal power unit i at times t and t-1, respectively. These are the maximum rates of downward and upward climbing for pure condensing thermal power unit i, respectively. The power system power balance constraints are as follows: ; In the formula, Let be the magnitude of the load at time t; The heat balance expression for a thermodynamic system is as follows: ; In the formula, Let be the heat load at time t. Let be the heat loss of pipe i at time t. For the number of pipes, The change in heat stored in pipe i at time t is expressed as follows: ; In the formula, Consider delay for pipe i The stored heat power during the process from t-1 to t, Temperatures at the end of pipe i at times t and t-1, respectively; To ensure the stability of the heating network, the stored heat in one cycle is 0, specifically: In the formula, T represents the total number of time periods; the system's net load and the flexibility supply of pure condensing thermal power units meet the following requirements: The net load expression for the entire system is as follows: ; In the formula, Let be the net load at time t; The flexibility offered by pure condensing thermal power units is as follows: ; In the formula, These refer to the upward and downward flexible power supply of pure condensing thermal power units at time t. These are the upper and lower limits of the output of pure condensing thermal power units; The maximum upward and downward climbing speed of a pure condensing thermal power unit; For time intervals.

[0031] S104. Based on the obtained optimal operating parameters, calculate the system net load and multi-dimensional flexibility indicators, quantitatively analyze the overall system regulation capability, and verify the supporting effect of the heating network on the flexibility of the power grid.

[0032] The multi-dimensional flexibility indicators also include the flexibility supply of CHP units and the total system flexibility supply; the flexibility supply of CHP units is as follows: ; In the formula, These represent the upward and downward flexibility supply of the CHP unit at time t, respectively. These represent the maximum and minimum output of the CHP unit at time t, respectively; These represent the maximum downward and upward climbing speeds of the i-th combined heat and power unit, respectively. Let be the output electrical power of the i-th combined heat and power unit at time t; The flexibility provided by the integrated units is as follows: ; in, These are units that provide flexibility, offering both upward and downward flexibility.

[0033] See Figure 4 The System Overall Flexibility (OSF) index is selected to measure the overall system's flexibility and adaptability, reflecting its overall responsiveness to demand fluctuations. ; in, Let be the net load at time t+1 and time t, and the difference between them represent the fluctuation of the net load. It can reflect the difference between the flexibility provided by the system's upward and downward adjustments at time t and the predicted fluctuation value of the net load.

[0034] See Figure 5 , Figure 6 and Figure 7 The expected value (IRRE) of insufficient system climbing resources is used to evaluate the flexible climbing capability of the entire system, specifically: ; in, These are the up-adjustment and down-adjustment discrete cumulative distribution functions, respectively, used to characterize the distribution characteristics of the system's flexible adjustment capability at a given time scale; This represents the change in net load at time t. These are the net loads at times t and t-1, respectively. This indicates that time t is on a time scale of Changes in net load under the following conditions The time scales are respectively The upward and downward flexibility requirements due to changes in net load at time t; T is the total number of time periods. These represent the time period t and the time scale, respectively. The system adjusts the probability of insufficient ramp resources by increasing or decreasing them; its expression includes... This is used to describe the probabilistic situation where the supply of flexibility is just insufficient to cover the demand for changes in net load. Each within the entire cycle The system adjusts the expected value of insufficient ramp resources upwards and downwards over a time scale.

[0035] The quantitative analysis system's overall adjustment capability is used to verify the supporting effect of the heating network on the flexibility of the power grid, specifically as follows: Under the same cold-region electric heating system, the same electric / heat load, the same new energy output sequence, and the same unit parameters, only the inertia of the heating network is changed. Experimental group: Including the inertia of the heating network, considering thermal delay and heat loss, the heating network has the ability to store and regulate heat; Control group: without heating network inertia (static heating network model), ignoring thermal delay and heat loss, assuming instantaneous response of the heating network (no heat storage in the pipeline, and consistent supply and return water temperatures in real time), and the remaining constraints (unit ramp-up, power / heat balance) are completely consistent with the experimental group.

[0036] According to the optimization logic of this invention, the two sets of scenarios are solved separately to obtain: the power generation output of CHP units and pure condensing thermal power units at each time; the power consumption and heat output of heat pumps; the supply and return water temperatures of the heating network and the heat storage of pipelines (only available for the experimental group).

[0037] For the optimization results of the two sets of scenarios, the following two types of key indicators were calculated to ensure a consistent comparison dimension: The overall flexibility index (OSF) of a computing system is calculated over the entire lifecycle. and The average and peak values.

[0038] Insufficient climbing resources Expected value IRRE, statistically averaged over the entire period.

[0039] The difference between the experimental group and the control group was calculated to quantify the improvement: if the average OSF increase is ≥10% and the average IRRE decrease is ≥15%, then the effect of heating network inertia on grid flexibility is verified.

[0040] See Figure 8This invention discloses a novel power system flexibility enhancement system for cold regions based on heating network inertia, comprising: The acquisition module, based on the typical structure of an integrated electric and thermal energy system in cold regions, identifies the core components of the integrated electric and thermal energy system; and collects the electrical load, thermal load, and new energy output data required for the operation of the system to form a standardized input dataset. The construction module, based on the acquired standardized input dataset, integrates the thermal inertia characteristics of the heating network to construct an electrothermal synergistic model characterizing the coupling relationship between the thermal system and the power system. The solution module aims to minimize the full-cycle operating cost of the electrothermal synergy model. It solves for the operating parameters of the electrothermal synergy model by combining the power system power balance, unit output limits, and thermal system heat balance constraints. The quantification module calculates the system's net load and multi-dimensional flexibility indicators based on the obtained optimal operating parameters, quantifies and analyzes the overall system regulation capability, and verifies the supporting effect of the heating network on the power grid's flexibility.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network, characterized in that, include: Based on the typical structure of integrated electric and thermal energy systems in cold regions, the core components of integrated electric and thermal energy systems are determined. It also collects electrical load, thermal load, and renewable energy output data required for the system's operation, forming a standardized input dataset; Based on the obtained standardized input dataset, and by integrating the thermal inertia characteristics of the heating network, an electrothermal synergistic model characterizing the coupling relationship between the thermal system and the power system is constructed. With the goal of minimizing the full-cycle operating cost of the electrothermal synergy model, the operating parameters of the electrothermal synergy model are solved by combining the power system power balance, unit output limits and thermal system heat balance constraints. Based on the obtained optimal operating parameters, the net load and multi-dimensional flexibility indicators of the system are calculated, the overall regulation capability of the system is quantitatively analyzed, and the supporting effect of the heating network on the flexibility of the power grid is verified.

2. The method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network according to claim 1, characterized in that, The core components include a combined heat and power (CHP) unit, a heat pump, and a condensing thermal power unit. The CHP unit operates in extraction mode, and its output electrical power and thermal power at time t satisfy the following relationship: The feasible operating range for a combined heat and power (CHP) plant is based on the output thermal power. The horizontal axis represents electrical power. The vertical axis represents the region formed by the corner points of the combined heat and power (CHP) plant, along with the horizontal and vertical axes. The electrothermal power coordinates of its corner points are as follows: The CHP unit operates under extraction steam conditions, and its output electrical power and output thermal power at time t satisfy the following relationship: ; And the combination coefficient Satisfy constraints: ; ; in, Let be the output electrical power of the i-th CHP unit at time t. Let be the output thermal power of the i-th CHP unit at time t. Let x and y be the x and y coordinates of the i-th CHP unit in the hotspot feasible region. The total number of CHP corner points of the i-th cogeneration unit.

3. The method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network according to claim 2, characterized in that, The thermodynamic system portion of the electrothermal synergistic model includes a mass flow equation, which is: ; Meanwhile, the thermal system also includes heat exchange equations for heat source nodes, which satisfy the following: ; in, Let the mass flow rate be the mass flow rate from node j to node i. Let be the mass flow rate of hot water flowing from node i into node k. Each of these represents a set of pipes connected to node i, with node i as both the starting and ending point. The heat supplied by heat source node i at time t. The specific heat capacity of water, Let represent the mass flowing through heat source node i, and HS represent the set of heat source nodes. Let t represent the temperatures of heat source node i in the water supply pipe and the return pipe at time t, respectively.

4. The method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network according to claim 3, characterized in that, The thermal system section also includes heat load heat exchange equations and supply and return water temperature constraints, wherein the heat load heat exchange equations satisfy: ; The supply and return water temperature constraints satisfy: ; in, Let be the heat absorbed by heat load node i at time t. Let be the mass flowing through load node i; L represents the set of heat load nodes. These are the lower and upper limits of the water supply temperature, respectively. These are the lower and upper limits of the return water temperature, respectively. The thermal inertia characteristics of the heating network are quantified by thermal delay and heat loss, which satisfy the following formula: ; In the formula, For the delay of pipe i during transmission, The density of water, Let i be the length of pipe i. Let i be the inner diameter of pipe i. Let i be the flow rate of pipe i; For pipe i after the delay, at time... The temperature of the hot water at the end of the pipe, Let be the temperature of the hot water at the beginning of pipe i during time period t. The temperature outside the pipe, This is the heat conversion coefficient per unit length of the pipe. Let be the flow rate of pipe i during time period t. For pipe i in t to Heat loss during the process.

5. The method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network according to claim 4, characterized in that, The heat pump's heat output and electrical power consumption at time t satisfy the following: ; in, Let be the heat output of the k-th heat pump at time t. Let be the electrical power consumed by the k-th heat pump at time t. Let be the electro-thermal efficiency of the k-th heat pump. This represents the upper limit of the heat output of the k-th heat pump; The ramp-up constraint for the CHP cogeneration unit is: ; in, These are the maximum downward and upward climbing rates of the i-th cogeneration unit, respectively; denoted as and respectively, represent the output electrical power of the i-th combined heat and power unit at times t and t-1.

6. The method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network according to claim 5, characterized in that, The objective is to minimize the total lifecycle operating cost of the electrothermal synergy model, satisfying the following: ; Where F is the cost over the entire period, and T is the total number of time periods. Let be the cost of the i-th pure condensing thermal power unit at time t. This refers to the number of pure condensing thermal power units. The cost of the j-th CHP unit at time t, This refers to the number of CHP units. Let the cost of the k-th heat pump at time t be... For the number of heat pumps, This is a penalty for abandoning wind and light. The cost of a conventional condensing unit is determined by its output electrical power, while the cost of a CHP unit is determined by both its output thermal power and electrical power. The specific costs of each component are as follows: ; in, These are the coefficients for pure condensing thermal power units, with units of yuan / h, yuan / (MW·h), and yuan / , The coefficients for CHP units are , with units of yuan / h, yuan / (MW·h), yuan / (MW·h), and yuan / (MW·h), respectively. 2 ·h), yuan / (MW) 2 ·h), yuan / (MW) 2 ·h), The coefficient of performance (COP) for heat pumps is expressed in yuan per (MW·h). The penalty coefficient for wind and solar power curtailment is expressed in yuan / (MW·h); Let be the electrical power output of condensing thermal power unit i at time t. Let be the electrical output and thermal output of the j-th CHP unit at time t, respectively. Let be the electrical power consumed by the k-th heat pump at time t. These represent the predicted and actual power output of wind farm i at time t, respectively. These represent the predicted and actual power output of photovoltaic power station i at time t, respectively. These are the numbers of wind farms and photovoltaic power plants, respectively. The constraints of pure condensing thermal power units are as follows: ; In the formula, These are the lower and upper limits of the output of pure condensing thermal power units, respectively. Let i represent the output of a pure condensing thermal power unit i at times t and t-1, respectively. These are the maximum rates of downward and upward climbing for pure condensing thermal power unit i, respectively. The power system power balance constraints are as follows: ; In the formula, Let be the magnitude of the load at time t; The heat balance expression for a thermodynamic system is as follows: ; In the formula, Let be the heat load at time t. Let be the heat loss of pipe i at time t. For the number of pipes, The change in heat stored in pipe i at time t is expressed as follows: ; In the formula, Consider delay for pipe i The stored heat power during the process from t-1 to t, Temperatures at the end of pipe i at times t and t-1, respectively; To ensure the stability of the heating network, the stored heat in one cycle is 0, specifically: In the formula, T represents the total number of time periods.

7. The method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network according to claim 6, characterized in that, The system's net load and the flexibility of pure condensing thermal power units are met: The net load expression for the entire system is as follows: ; In the formula, Let be the net load at time t; The flexibility offered by pure condensing thermal power units is as follows: ; In the formula, These refer to the upward and downward flexible power supply of pure condensing thermal power units at time t. These are the upper and lower limits of the output of pure condensing thermal power units; The maximum upward and downward climbing speed of a pure condensing thermal power unit; For time intervals.

8. The method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network according to claim 7, characterized in that, The multi-dimensional flexibility indicators also include the flexibility supply of CHP units and the total system flexibility supply; the flexibility supply of CHP units is as follows: ； In the formula, These represent the upward and downward flexibility supply of the CHP unit at time t, respectively. These represent the maximum and minimum output of the CHP unit at time t, respectively; The flexibility provided by the integrated units is as follows: ; in, These are units that provide flexibility, offering both upward and downward flexibility.

9. The method for improving the flexibility of a novel power system in cold regions based on the inertia of a heating network according to claim 8, characterized in that, The multi-dimensional flexibility index also includes the expected value of insufficient system ramping resources (IRRE), which satisfies: ; in, These are the up-adjustment and down-adjustment discrete cumulative distribution functions, respectively, used to characterize the distribution characteristics of the system's flexible adjustment capability at a given time scale; This represents the change in net load at time t. These are the net loads at times t and t-1, respectively. This indicates that time t is on a time scale of Changes in net load under the following conditions The time scales are respectively The upward and downward flexibility requirements due to changes in net load at time t; T is the total number of time periods. These represent the time period t and the time scale, respectively. The system adjusts the probability of insufficient ramp resources by increasing or decreasing them. Each within the entire cycle The system adjusts the expected value of insufficient ramp resources upwards and downwards over a time scale.

10. A new power system for cold regions based on the inertia of a heating network to enhance flexibility, characterized in that: include: The acquisition module, based on the typical structure of an integrated electric and thermal energy system in a cold region, determines the core constituent units of the integrated electric and thermal energy system. It also collects electrical load, thermal load, and renewable energy output data required for the system's operation, forming a standardized input dataset; The construction module, based on the acquired standardized input dataset, integrates the thermal inertia characteristics of the heating network to construct an electrothermal synergistic model characterizing the coupling relationship between the thermal system and the power system. The solution module aims to minimize the full-cycle operating cost of the electrothermal synergy model. It solves for the operating parameters of the electrothermal synergy model by combining the power system power balance, unit output limits, and thermal system heat balance constraints. The quantification module calculates the system's net load and multi-dimensional flexibility indicators based on the obtained optimal operating parameters, quantifies and analyzes the overall system regulation capability, and verifies the supporting effect of the heating network on the power grid's flexibility.

Images