Thermal power generation cell energy storage collaborative control method

Abstract

The present application relates to the field of power system dispatching and control, and particularly relates to a thermal power generation battery energy storage collaborative control method. The content includes: real-time acquisition of thermal power unit output, battery energy storage system charging and discharging power and battery state of charge, construction of a collaborative control system state vector, and obtaining of a basic control deviation; based on the basic control deviation, construction of a potential function and a coordination function; based on the potential function and the coordination function, construction of a state evolution equation, conversion of system state evolution results into dispatching instructions and distribution, and realization of collaborative control. The traditional collaborative control method lacks modeling and adjustment of the complex coupling relationship between the thermal power unit and the battery energy storage system, resulting in excessive or insufficient adjustment during load change; the dispatching instruction fails to fully consider the influence of time dynamic change, the adjustment process lacks smoothness, and excessive adjustment or delayed response is easily caused, thereby increasing the operation cost and system instability risk.

Description

Technical Field

[0001] This invention relates to the field of power system dispatching and control, and in particular to a method for coordinated control of thermal power generation and battery energy storage. Background Technology

[0002] With the transformation of the global energy structure and the widespread application of renewable energy, the load volatility and uncertainty of power systems are increasing. Traditional thermal power generating units, due to their limited response speed and flexibility, are finding it difficult to meet the grid's demands for frequency regulation and load balancing. Meanwhile, battery energy storage systems, as a rapid-response regulation method, are gradually becoming an effective way to solve this problem. Battery energy storage systems can provide or absorb electrical energy in a short time to smooth grid load fluctuations and alleviate the burden on traditional thermal power units. However, thermal power units and battery energy storage systems are usually controlled independently, lacking an effective coordinated regulation mechanism.

[0003] To achieve efficient dispatch and stable operation of the power system, a new control method is urgently needed that can simultaneously coordinate the regulation behavior of thermal power units and battery energy storage systems, fully utilizing their respective characteristics to achieve optimal load tracking and energy management. By dynamically adjusting the output of thermal power units and battery energy storage systems and optimizing the regulation path, the power system can be ensured to respond quickly to changes in load demand while maintaining stability, thereby improving the overall efficiency and reliability of the power system.

[0004] Traditional coordinated control methods have the following technical problems: most of them do not consider the difference in regulation rates between thermal power units and battery energy storage systems, and lack modeling and regulation of the complex coupling relationship between the two, which leads to over-regulation or under-regulation during load changes, affecting the stability and economy of the power grid; dispatching commands are often based on static models and fail to fully consider the impact of dynamic changes over time, resulting in a lack of smoothness in the regulation process, which can easily lead to over-regulation or untimely response, thereby increasing operating costs and the risk of system instability. Summary of the Invention

[0005] This invention provides a method for coordinated control of thermal power generation and battery energy storage, which addresses the problems of traditional coordinated control methods that mostly fail to consider the difference in regulation rates between thermal power units and battery energy storage systems, lack modeling and regulation of the complex coupling relationship between the two, leading to over-regulation or under-regulation during load changes, affecting the stability and economy of the power grid; dispatching commands are also often based on static models, failing to fully consider the impact of dynamic changes over time, and the regulation process lacks smoothness, easily leading to over-regulation or untimely response, thereby increasing operating costs and system instability risks.

[0006] The present invention provides a method for coordinated control of energy storage in thermal power generation batteries, specifically comprising the following technical solutions: A method for coordinated control of thermal power generation battery energy storage includes the following steps: S1. Real-time acquisition of thermal power unit output, battery energy storage system charging and discharging power and battery state of charge, constructing the state vector of the cooperative control system and obtaining the basic control deviation; based on the basic control deviation, constructing the potential function and coordination function; based on the potential function and coordination function, constructing the state evolution equation, capturing the changing trend of the state vector of the cooperative control system, and obtaining the system state evolution result; S2. The system state evolution results are converted into scheduling instructions and allocated, generating output correction instructions for thermal power units and charging / discharging power correction instructions for battery energy storage systems to achieve coordinated control.

[0007] Preferably, S1 specifically includes: The predicted load is obtained by forecasting load demand through the dispatching master station; the basic control deviation is obtained by combining the power output of thermal power units and the charging and discharging power of battery energy storage systems with the predicted load.

[0008] Preferably, S1 specifically includes: Based on the output of the thermal power unit, the adjustment rate of the thermal power unit is calculated, and a potential function is constructed by combining the deviation between the battery state of charge and the reference value and the basic control deviation.

[0009] Preferably, S1 specifically includes: Based on the charging and discharging power of the battery energy storage system, the regulation rate of the battery energy storage system is calculated; based on the regulation rate of the thermal power unit and the regulation rate of the battery energy storage system, and by introducing a coupling gain coefficient, a coordination function is constructed.

[0010] Preferably, S1 specifically includes: The state evolution equation calculates the gradient of the potential function with respect to the state vector of the cooperative control system, and introduces a coordination function as the driving force and direction adjustment quantity for dynamic evolution. This quantifies the dynamic change process of the thermal power unit and the battery energy storage system in the time dimension, and yields the system state evolution result.

[0011] Preferably, S2 specifically includes: By introducing a time decay factor, a time-weighted control output function is constructed to weight the state evolution process and transform the system state evolution result into an executable scheduling instruction.

[0012] Preferably, S2 specifically includes: By introducing a control weighting coefficient, the dispatching command is decomposed into the output correction command of the thermal power unit and the charging and discharging power correction command of the battery energy storage system.

[0013] Preferably, S2 specifically includes: The control weight coefficient of the thermal power unit is obtained based on the current output of the thermal power unit, combined with the maximum and minimum output of the thermal power unit; the control weight coefficient of the battery energy storage system is obtained based on the current state of charge of the battery and the charging and discharging power of the battery energy storage system, combined with the rated charging and discharging power of the battery energy storage system and the upper and lower limits of the battery state of charge.

[0014] The beneficial effects of the technical solution of the present invention are: 1. This invention collects real-time data on the output of thermal power units, the charging and discharging power of battery energy storage systems, and the state of charge of batteries. By predicting load demand through the dispatching master station, it can accurately calculate instantaneous load deviations, providing precise control deviation inputs for subsequent regulation. The introduction of the potential function further optimizes the regulation strategy of thermal power units and battery energy storage systems, effectively reducing the regulation error between thermal power units and battery energy storage systems, thereby improving the regulation accuracy and response speed of the coordinated control system.

[0015] 2. The coordination function designed in this invention dynamically adjusts the adjustment priority and direction of the two based on the difference in adjustment rates between the thermal power unit and the battery energy storage system. By optimizing the adjustment path in real time, it ensures that the optimal adjustment decision can be made according to the real-time status when the power demand changes rapidly, thus avoiding the risk of system instability caused by slow or excessive adjustment.

[0016] 3. This invention transforms the system state evolution results into smooth control commands by constructing a time-weighted control output function, avoiding excessive interference of early errors on the current commands; by reasonably allocating control weight coefficients, it ensures that thermal power units and battery energy storage systems can coordinate and cooperate to achieve system objectives according to their dynamic characteristics, thereby improving scheduling efficiency and response capability. Attached Figure Description

[0017] Figure 1 This is a flowchart of a collaborative control method for thermal power generation battery energy storage according to the present invention. Detailed Implementation

[0018] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. 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.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] The following description, in conjunction with the accompanying drawings, details a specific scheme for a collaborative control method for energy storage in thermal power generation batteries provided by the present invention.

[0021] See attached document Figure 1 The diagram illustrates a flowchart of a collaborative control method for thermal power generation battery energy storage provided by an embodiment of the present invention. The method includes the following steps: S1. Real-time acquisition of thermal power unit output, battery energy storage system charging and discharging power and battery state of charge, constructing the state vector of the cooperative control system and obtaining the basic control deviation; based on the basic control deviation, constructing the potential function and coordination function; based on the potential function and coordination function, constructing the state evolution equation, capturing the changing trend of the state vector of the cooperative control system, and obtaining the system state evolution result; The system collects real-time data on the output of thermal power units, the charging and discharging power of battery energy storage systems, and the state of charge (SBC) of batteries. All data is uploaded to the control center via a dispatch communication link to construct a state vector for the collaborative control system. The dispatch master station then generates a predicted load (i.e., load demand) based on a short-term load model, providing real-time input for subsequent error calculation, potential function construction, and system state evolution. This ensures the control process has a complete physical data foundation and timely support. The output of the thermal power units is directly read by the unit's automatic control system (DCS). The charging and discharging power and SBC of the battery energy storage system are provided by the battery management system (BMS). The short-term load model can be implemented using an ARIMA time series model, using historical load data, current real-time load data, and preset influencing factors as input to generate the predicted load. The historical load data and current real-time load data are exported through a data platform. The influencing factors include time characteristics (e.g., time information, weekday / non-weekday information) and environmental characteristics (e.g., temperature, humidity). The dispatch master station updates the prediction results for the current period and extracts the corresponding predicted load value as the load demand. .

[0022] To achieve coordinated operation of thermal power units and battery energy storage systems during joint power output, a basic control deviation must first be established to drive the entire control logic. This basic control deviation reflects the instantaneous imbalance between the current total output of the coordinated control system (including the output of thermal power units and the charging and discharging power of battery energy storage systems) and the predicted load, and its magnitude directly determines the direction and intensity of subsequent adjustment actions. Therefore, the basic control deviation is defined as: ; in, The basic control deviation at time 𝑡, i.e., the load deviation, is used to measure the difference between the actual output of the coordinated control system and the grid load demand. This indicates the output of the thermal power unit at time 𝑡; This represents the charging and discharging power of the battery energy storage system at time 𝑡. This represents the load demand of the power grid at time 𝑡. The difference between the total output of the coordinated control system and the load demand at the current moment is calculated in real time and used as the deviation that the coordinated control system must eliminate. To construct an overall performance index that possesses physical consistency and reflects the comprehensive adjustment state of the coordinated control system, a potential function needs to be constructed to quantify the overall deviation of the coordinated control system's operating state from the target adjustment trajectory. This function not only reflects the matching deviation between the total output of the thermal power unit and the charging and discharging power of the battery energy storage system and the load demand, but also encompasses the dynamic response characteristics of the thermal power unit and the state stability of the battery energy storage system. This allows for unified coordination of multiple operating factors at the scheduling level. The specific expression of the potential function is as follows: ; in, It is a potential function, representing that at The total energy state of the system at any given moment; express The square of the load deviation at any given time; This indicates the adjustment cost of thermal power units. Due to the thermal inertia of thermal power units during ramp-up, increasing the ramp-up rate will increase the operating cost and risk of the coordinated control system. It is a penalty coefficient used to control the adjustment rate of thermal power units, representing the adjustment rate (climbing rate) of the thermal power unit. The penalty intensity ranges from [0,1]. Representative at Battery state of charge at all times Compared with reference value To minimize deviations and ensure that the battery energy storage system does not deviate from the safe range due to overcharging and discharging. Battery state of charge Compared with reference value The penalty coefficient for deviation represents the tolerance of the battery energy storage system to deviations in battery state of charge during the adjustment process, and its value ranges from [0,1]. This is a reference value, representing the ideal state of charge level of the battery. It is set according to the battery technology and is not limited here. and The weights are obtained through linear quadratic regulation (LQR) tuning, specifically based on the state vector of the cooperative control system. A linear state-space model is constructed, and the optimal feedback gain matrix is ​​obtained by solving the Riccati equation. The weights of the corresponding thermal power unit regulation components in the control weighting matrix are then mapped to the regulation rates of the thermal power units. Penalty coefficient The weights corresponding to the battery state of charge deviations in the state weighting matrix are mapped to the battery state of charge. Compared with reference value The penalty coefficient for the deviation ; The regulation behavior of thermal power units and battery energy storage systems needs to be coordinated to achieve optimal results. To further realize the dynamic coordination between thermal power units and battery energy storage systems, a coordination function is designed to reflect the dynamic regulation relationship between them. Specifically, thermal power units and battery energy storage systems have different regulation rates, and their regulation behaviors must be balanced through a mechanism. The coordination function dynamically adjusts the regulation priority and direction of the two by comparing the difference in their regulation rates. When the regulation rate of the battery energy storage system (i.e., charge / discharge rate) is faster than that of the thermal power unit (i.e., ramp rate), the coordination function will encourage the battery energy storage system to participate more in load regulation; conversely, the coordination function will suppress the rapid response of the battery energy storage system to promote the thermal power unit to dominate load regulation. The coordination function ensures that the cooperative control system can optimize the regulation path according to the real-time status under rapidly changing load demands, thereby achieving a balance between the stability and efficiency of the cooperative control system. The coordination function is calculated as follows: ; in, yes The coordination function between the thermal power unit and the battery energy storage system at any given time represents the synergistic effect of the regulation between the thermal power unit and the battery energy storage system. It is the coupling gain coefficient, which represents the adjustment coupling strength between the thermal power unit and the battery energy storage system. It is obtained through a step response test based on system identification and has a value range of [0,1]. This is the sensitivity ratio of the adjustment rate between the thermal power unit and the battery energy storage system, representing the relative relationship between the adjustment rates of the thermal power unit and the battery energy storage system. It can be set as the ratio of the maximum charge / discharge rate of the battery energy storage system to the maximum ramp rate of the thermal power unit. The maximum charge / discharge rate of the battery energy storage system is provided by the battery management system and can be the rated charge / discharge power of the battery energy storage system. The maximum ramp rate of the thermal power unit is provided by the unit control system and can be the rated ramp rate designed for the unit. The value range is [0,1]. Based on the potential function and coordination function, a state evolution equation is constructed to describe the dynamic changes of the thermal power unit and the battery energy storage system in the time dimension. This equation characterizes the rate of change of the thermal power unit output, the battery energy storage system's charging and discharging power, and the battery's state of charge over time, thereby capturing the changing trend of the state vector of the coordinated control system. By dynamically adjusting the thermal power unit output and the battery energy storage system's charging and discharging power, the system ensures that the load demand of the coordinated control system can be accurately responded to at different time steps, and avoids instability caused by slow response or over-adjustment. The state evolution equation is as follows: ; in, It is the result of system state evolution, representing the state vector of the cooperative control system. exist The rate of change at any given time, that is, the rate at which the system state evolves over time. ; Represents the potential function The gradient of the state vector of the cooperative control system reflects the direction of contribution of each variable to the potential function, that is, the steepest descent direction, ensuring that the cooperative control system automatically approaches the minimum potential energy point. It is the product of the coordination function and the coupling control matrix, representing the interaction between the thermal power unit and the battery energy storage system, and determining how the two compensate for each other during time evolution. The coupling control matrix represents the regulation relationship between the thermal power unit and the battery energy storage system, and its form is: The above state evolution equations introduce a coordination function. As the driving force and directional adjustment quantity for dynamic evolution, it realizes the dynamic evolution of the entire cooperative control system; By constructing state evolution equations, the power output of thermal power units, the charging and discharging power of battery energy storage systems, and the state of charge of batteries are tightly coupled. The adjustment coupling effect of thermal power units and battery energy storage systems is also considered. The interdependence between various variables is accurately modeled, resulting in a nonlinear coupled dynamic system. This system can adjust various control signals according to real-time errors and dynamic feedback, thereby driving thermal power units and battery energy storage systems to jointly optimize power output, thus ensuring the load regulation efficiency and stability of the coordinated control system.

[0023] S2. The system state evolution results are converted into scheduling instructions and allocated, generating output correction instructions for thermal power units and charging / discharging power correction instructions for battery energy storage systems to achieve coordinated control.

[0024] To transform the system state evolution results into executable scheduling instructions, a time-weighted control output function needs to be constructed to weight the state evolution process, thereby smoothing the control output signal and obtaining the scheduling instructions. Specifically, a time decay factor is introduced. This approach assigns higher weights to the current state and states within more recent time steps, while the contribution of states from more distant time steps gradually decreases. The scheduling instructions are transformed into output correction instructions for thermal power units and charging / discharging power correction instructions for battery energy storage systems through the actual execution layer, thereby achieving coordinated scheduling. The time-weighted control output function is specifically expressed as follows: ; in, It is the control output signal of the coordinated control system, that is, in Scheduling instructions generated at any time; This is a time decay factor, representing the degree to which the influence of past states on the control output of the current coordinated control system decays. More recent states are given higher weight to avoid excessive interference from early errors with current scheduling commands. The time decay factor is obtained through simulation calibration using a parameter identification method based on model simulation. Specifically, the calculation method is as follows: A dynamic simulation model of the power system is constructed, which includes at least a dynamic model of a thermal power unit and a dynamic model of a battery energy storage system. The dynamic model of the thermal power unit describes the dynamic response relationship between the unit output and the ramp rate, while the dynamic model of the battery energy storage system describes the dynamic coupling relationship between the charging / discharging power and the battery state of charge. The data used for parameter identification comes from historical operating data and simulation-generated data. The historical operating data includes the output of the thermal power unit, the charging / discharging power of the battery energy storage system, the battery state of charge, and load data. The simulation-generated data is obtained by applying load disturbances and power disturbances. A control performance index function based on load deviation is constructed and optimized using the least squares method or particle swarm optimization algorithm, with a value range of [0.01, 1]. It is a time integral variable; Represents the state vector of the coordinated control system exist Rate of change over time; Output scheduling instructions This is based on the state evolution results of the entire coordinated control system. To ensure that the thermal power unit and the battery energy storage system can work in a coordinated manner and each execute control actions consistent with the overall scheduling objective, a control weighting coefficient is introduced to adjust the scheduling commands. The dispatch instructions should be allocated appropriately, ensuring their effective application to both thermal power units and battery energy storage systems. Decomposed into output correction commands for thermal power units and the charge / discharge power correction command of the battery energy storage system The specific allocation formula is as follows: ; ; in, and These are the control weighting coefficients for thermal power units and battery energy storage systems, respectively. This value is used to characterize the ability of a thermal power unit to participate in regulation at the current moment. It is dynamically determined based on the real-time adjustability margin of the thermal power unit and is defined as follows: , These are the maximum and minimum output of the thermal power unit, respectively, which are obtained in real time by the unit's control system. This indicates the real-time adjustability margin of the thermal power unit; This value is used to characterize the ability of a battery energy storage system to participate in regulation at the current moment. It is dynamically determined based on the battery's state of charge and charge / discharge power margin. Specifically: , The rated charge and discharge power of the battery energy storage system. and These are the upper and lower limits of the permissible state of charge of the battery, which are preset by the battery energy storage system.

[0025] Control signals are effectively distributed to specific adjustment commands for thermal power units and battery energy storage systems, thereby ensuring that the coordinated control system can respond quickly to load fluctuations during the adjustment process, balance the capacity differences between thermal power units and battery energy storage systems, and ultimately achieve coordinated adjustment between thermal power units and battery energy storage systems.

[0026] In summary, a collaborative control method for thermal power generation and battery energy storage has been developed.

[0027] The order of the embodiments is for illustrative purposes only and does not represent the superiority or inferiority of the embodiments. The processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0028] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0029] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for coordinated control of thermal power generation and battery energy storage, characterized in that, Includes the following steps: S1. Real-time acquisition of thermal power unit output, battery energy storage system charging and discharging power and battery state of charge, constructing the state vector of the collaborative control system, and obtaining the basic control deviation; Based on the basic control deviation, a potential function and a coordination function are constructed; based on the potential function and the coordination function, a state evolution equation is constructed to capture the changing trend of the state vector of the cooperative control system and obtain the system state evolution result. S2. The system state evolution results are converted into scheduling instructions and allocated, generating output correction instructions for thermal power units and charging / discharging power correction instructions for battery energy storage systems to achieve coordinated control.

2. The method for coordinated control of thermal power generation battery energy storage according to claim 1, characterized in that, S1 specifically includes: The predicted load is obtained by forecasting load demand through the dispatching master station; the basic control deviation is obtained by combining the power output of thermal power units and the charging and discharging power of battery energy storage systems with the predicted load.

3. The method for coordinated control of thermal power generation battery energy storage according to claim 2, characterized in that, S1 specifically includes: Based on the output of the thermal power unit, the adjustment rate of the thermal power unit is calculated, and a potential function is constructed by combining the deviation between the battery state of charge and the reference value and the basic control deviation.

4. The method for coordinated control of thermal power generation battery energy storage according to claim 3, characterized in that, S1 specifically includes: Based on the charging and discharging power of the battery energy storage system, the regulation rate of the battery energy storage system is calculated; based on the regulation rate of the thermal power unit and the regulation rate of the battery energy storage system, and by introducing a coupling gain coefficient, a coordination function is constructed.

5. The method for coordinated control of thermal power generation battery energy storage according to claim 4, characterized in that, S1 specifically includes: The state evolution equation calculates the gradient of the potential function with respect to the state vector of the cooperative control system, and introduces a coordination function as the driving force and direction adjustment quantity for dynamic evolution. This quantifies the dynamic change process of the thermal power unit and the battery energy storage system in the time dimension, and yields the system state evolution result.

6. The method for coordinated control of thermal power generation battery energy storage according to claim 1, characterized in that, S2 specifically includes: By introducing a time decay factor, a time-weighted control output function is constructed to weight the state evolution process and transform the system state evolution result into an executable scheduling instruction.

7. The method for coordinated control of thermal power generation battery energy storage according to claim 6, characterized in that, S2 specifically includes: By introducing a control weighting coefficient, the dispatching command is decomposed into the output correction command of the thermal power unit and the charging and discharging power correction command of the battery energy storage system.

8. The method for coordinated control of thermal power generation battery energy storage according to claim 7, characterized in that, S2 specifically includes: The control weight coefficient of the thermal power unit is obtained based on the current output of the thermal power unit, combined with the maximum and minimum output of the thermal power unit; the control weight coefficient of the battery energy storage system is obtained based on the current state of charge of the battery and the charging and discharging power of the battery energy storage system, combined with the rated charging and discharging power of the battery energy storage system and the upper and lower limits of the battery state of charge.

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