A carbon dioxide energy storage system scheduling method and system for grid peak shaving

Abstract

The present application relates to the technical field of smart grid, and discloses a carbon dioxide energy storage system scheduling method and system for peak shaving and valley filling of power grid, the method comprising: obtaining power grid operation state data and carbon dioxide energy storage system operation parameters; determining whether the current period is in a power consumption peak period or a power consumption valley period; when it is determined that the current period is in a power consumption valley period, controlling the carbon dioxide energy storage system to absorb excess power from the power grid through a compression process; when it is determined that the current period is in a power consumption peak period, controlling the carbon dioxide energy storage system to release stored carbon dioxide energy; and dynamically adjusting the energy storage power or the energy release power according to the operation parameters. The present application improves the operation stability of the energy storage system and the load regulation capability of the power grid, reduces the peak-valley difference of the power grid, and improves the power utilization efficiency.

Description

Technical Field

[0001] This invention relates to the field of smart grid technology, and more specifically, to a method and system for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in power grids. Background Technology

[0002] With the development of power systems and the increase in the proportion of renewable energy generation, the characteristics of power grid load fluctuations have become increasingly apparent. In actual operation, due to differences in user electricity demand at different times, the power grid experiences peak and off-peak loads at different times. Large load fluctuations increase the difficulty of grid operation and regulation, affecting the stable operation of the power system. Therefore, utilizing energy storage systems to store electrical energy during off-peak periods and release it during peak periods to achieve peak shaving and valley filling has become an important technical means to improve the grid's regulation capabilities.

[0003] Carbon dioxide energy storage systems utilize the energy conversion characteristics of carbon dioxide during compression and expansion. Through compression, electrical energy is converted into the internal energy of carbon dioxide for storage, and through expansion, power generation equipment is driven to output electrical energy. They are characterized by large energy storage capacity and flexible operation.

[0004] However, existing carbon dioxide energy storage systems typically employ preset operating strategies to control the energy storage and release processes during grid peak shaving and valley filling, making it difficult to dynamically adjust based on real-time grid load conditions and the system's own operating parameters. When grid load conditions change or operating parameters such as storage tank pressure and storage capacity fluctuate, the fixed dispatching method may lead to a mismatch between the energy storage or release power and the actual regulation demand, affecting the grid load regulation effect. Furthermore, if system operating parameters deviate from the appropriate range during the energy storage and release processes, it may also affect the stable operation of the carbon dioxide energy storage system.

[0005] Therefore, it is necessary to provide a method and system for scheduling carbon dioxide energy storage systems for peak shaving and valley filling in power grids to solve the problem that existing carbon dioxide energy storage systems cannot dynamically adjust according to changes in grid load and the operating status of the energy storage system, resulting in insufficient matching between energy storage power and energy release power and low system operating stability. Summary of the Invention

[0006] In view of this, the present invention proposes a method and system for scheduling carbon dioxide energy storage systems for peak shaving and valley filling of power grids, aiming to solve the problem that the existing carbon dioxide energy storage system scheduling process cannot dynamically adjust according to changes in power grid load and the operating status of the energy storage system, resulting in insufficient matching between energy storage power and energy release power and low system operation stability.

[0007] On the one hand, this invention proposes a method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in power grids, comprising: Acquire power grid operation status data and carbon dioxide energy storage system operating parameters; The current power grid load demand status is determined based on the power grid operation status data, and it is determined whether the current time period is a peak electricity consumption period or an off-peak electricity consumption period. When it is determined that the current period is a low electricity consumption period, the energy storage power of the carbon dioxide energy storage system is determined according to the operating parameters of the carbon dioxide energy storage system, and the carbon dioxide energy storage system is controlled to absorb excess power from the grid through the compression process, converting the power into the internal energy of carbon dioxide for storage. When it is determined that the current period is a peak electricity consumption period, the energy release power of the carbon dioxide energy storage system is determined according to the operating parameters of the carbon dioxide energy storage system, and the carbon dioxide energy storage system is controlled to release the stored carbon dioxide energy, and the power generation equipment is driven to output electrical energy to the grid through the expansion process. The system acquires real-time operating parameters of the carbon dioxide energy storage system during the energy storage and release processes, and dynamically adjusts the energy storage power or energy release power based on these operating parameters.

[0008] Furthermore, the power grid operation status data includes real-time load power, current time period information, and historical peak and valley time period information; The operating parameters of the carbon dioxide energy storage system include the energy storage tank pressure, energy storage capacity, and carbon dioxide flow rate.

[0009] Furthermore, determining the current grid load demand status based on the grid operation status data includes: The real-time load power is compared with the preset load threshold. If the real-time load power is greater than or equal to the preset load threshold, it is preliminarily determined that the current power grid load demand is in a high load state. If the real-time load power is less than the preset load threshold, it is preliminarily determined that the current power grid load demand is in a low load state. Based on the current time period information and historical peak-valley time period information, the current power grid load demand status is determined again: When it is initially determined that the current power grid load demand is in a low load state, check whether the current time period falls within the low valley range in the historical peak and valley time period information. If it is in the low valley range, then the current power grid is finally determined to be in a low load state; if it is not in the low valley range, then the current power grid is finally determined not to be in a low load state. When it is initially determined that the current power grid load demand is in a high load state, check whether the current time period falls within the peak range of the historical peak and valley time period information. If it is in the peak range, then the current power grid is finally determined to be in a high load state; if it is not in a high load state, then the current power grid is finally determined not to be in a high load state.

[0010] Furthermore, determining whether the current time period is during peak or off-peak electricity consumption includes: When the final determination result is that the current power grid is in a low load state, the current time period is determined to be a low electricity consumption period. When the final determination result is that the current power grid is under high load, it is determined that the current time period is a peak electricity consumption period.

[0011] Furthermore, when determining that the current period is a low-electricity consumption time, the step of determining the energy storage capacity of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system includes: Obtain the energy storage tank pressure, rated pressure value of the energy storage tank, energy storage capacity, and rated energy storage capacity of the carbon dioxide energy storage system; Calculate the difference between the rated pressure of the energy storage tank and the pressure of the energy storage tank to obtain the remaining pressure of the energy storage tank; Based on the remaining pressure of the energy storage tank and the correspondence between carbon dioxide pressure and stored energy, the remaining storable energy of the current energy storage tank is determined. Calculate the difference between the rated energy storage capacity and the energy storage capacity to obtain the remaining energy storage capacity; The remaining storable energy is compared with the remaining energy storage capacity, and the minimum value between the remaining storable energy and the remaining energy storage capacity is selected as the maximum energy that the carbon dioxide energy storage system can absorb. Obtain the remaining time during the current off-peak electricity period, calculate the ratio of the maximum energy storage capacity to the remaining time, and obtain the maximum energy storage power of the carbon dioxide energy storage system. The maximum energy storage power is compared with the rated power of the compressor, and the minimum value between the maximum energy storage power and the rated power of the compressor is determined as the energy storage power of the carbon dioxide energy storage system.

[0012] Furthermore, when determining that the current period is a peak electricity consumption time, determining the energy release power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system includes: Calculate the difference between the pressure of the energy storage tank and the preset minimum working pressure value to obtain the pressure release value of the energy storage tank; Based on the releasable pressure value of the energy storage tank and the correspondence between carbon dioxide pressure and released energy, the releasable energy of the current energy storage tank is determined. Calculate the difference between the energy storage capacity and the preset minimum energy storage capacity to obtain the current remaining releaseable energy storage capacity; Based on the current remaining releaseable energy storage capacity and the energy released per unit mass of carbon dioxide, determine the energy releaseable by the current carbon dioxide energy storage system; The maximum releaseable energy of the carbon dioxide energy storage system is obtained by comparing the releaseable energy of the current energy storage tank with the releaseable energy of the current carbon dioxide energy storage system and selecting the minimum value between the releaseable energy of the current energy storage tank and the releaseable energy of the current carbon dioxide energy storage system. Obtain the remaining time of the current peak electricity consumption period, calculate the ratio of the maximum releaseable energy to the remaining time, and obtain the maximum energy release power of the carbon dioxide energy storage system; The maximum energy release power is compared with the rated power of the expander, and the minimum value between the maximum energy release power and the rated power of the expander is determined as the energy release power of the carbon dioxide energy storage system.

[0013] Furthermore, the real-time acquisition of operating parameters of the carbon dioxide energy storage system during the energy storage and release processes, and the dynamic adjustment of the energy storage power or energy release power based on the operating parameters, includes: Acquire the energy storage tank pressure, carbon dioxide flow rate, compressor operating power, and expander operating power of the carbon dioxide energy storage system during the energy storage and release processes; Calculate the difference between the energy storage tank pressure at the current detection time and the energy storage tank pressure at the previous detection time to obtain the energy storage tank pressure change; calculate the difference between the carbon dioxide flow rate at the current detection time and the preset target flow rate to obtain the carbon dioxide flow rate deviation value; calculate the difference between the current compressor operating power and the preset energy storage power to obtain the energy storage power deviation value; calculate the difference between the current expander operating power and the preset energy release power to obtain the energy release power deviation value. When the pressure change of the energy storage tank is greater than a preset pressure change threshold, or the carbon dioxide flow deviation is greater than a preset flow deviation threshold, the operating power of the compressor or the operating power of the expander is reduced; when the energy storage power deviation or the energy release power deviation is greater than a preset power deviation threshold, the operating power of the compressor or the operating power of the expander is adjusted according to the energy storage power deviation or the energy release power deviation. The new energy storage power is determined based on the adjusted compressor operating power, or the new energy release power is determined based on the adjusted expander operating power.

[0014] Furthermore, when reducing the operating power of the compressor or the operating power of the expander and adjusting the operating power of the compressor or the operating power of the expander according to the energy storage power deviation value or the energy release power deviation value, the following steps are included: When the pressure change of the energy storage tank is greater than the preset pressure change threshold, the difference between the pressure change of the energy storage tank and the preset pressure change threshold is calculated to obtain the pressure over-limit, and the compressor operating power is reduced according to the pressure over-limit. When the carbon dioxide flow deviation value is greater than the preset flow deviation threshold, the difference between the carbon dioxide flow deviation value and the preset flow deviation threshold is calculated to obtain the flow deviation amount, and the carbon dioxide flow rate is adjusted according to the flow deviation amount; When the energy storage power deviation value is greater than the preset power deviation threshold, the difference between the energy storage power deviation value and the preset power deviation threshold is calculated to obtain the energy storage power adjustment amount, and the compressor operating power is adjusted according to the energy storage power adjustment amount; When the energy release power deviation value is greater than the preset power deviation threshold, the difference between the energy release power deviation value and the preset power deviation threshold is calculated to obtain the energy release power adjustment amount, and the expander operating power is adjusted according to the energy release power adjustment amount.

[0015] Furthermore, when determining the new energy storage power based on the adjusted compressor operating power, or the new energy release power based on the adjusted expander operating power, it includes: Obtain the adjusted compressor operating power and expander operating power; The adjusted compressor operating power is compared with the compressor rated power. If the adjusted compressor operating power is less than or equal to the compressor rated power, the adjusted compressor operating power is determined as the new energy storage power; if the adjusted compressor operating power is greater than the compressor rated power, the compressor rated power is determined as the new energy storage power. The adjusted operating power of the expander is compared with the rated power of the expander. If the adjusted operating power of the expander is less than or equal to the rated power of the expander, the adjusted operating power of the expander is determined as the new energy release power; if the adjusted operating power of the expander is greater than the rated power of the expander, the rated power of the expander is determined as the new energy release power. The energy storage process of the carbon dioxide energy storage system is controlled according to the new energy storage power, or the energy release process of the carbon dioxide energy storage system is controlled according to the new energy release power.

[0016] Compared with existing technologies, the beneficial effects of this invention are as follows: By acquiring grid operation status data and carbon dioxide energy storage system operating parameters, this invention determines peak or off-peak electricity demand periods based on the current grid load demand status, and controls the carbon dioxide energy storage system to store energy during off-peak periods and release energy during peak periods, thereby achieving peak shaving and valley filling regulation of the grid load. Simultaneously, by acquiring the operating parameters of the carbon dioxide energy storage system in real time during the energy storage and release processes, and dynamically adjusting the energy storage or release power based on these parameters, the carbon dioxide energy storage system can adaptively adjust according to its own operating status and grid load changes, improving the operational stability of the energy storage system and the grid load regulation capability, reducing the peak-valley difference in the grid, and improving energy utilization efficiency.

[0017] On the other hand, this application also provides a carbon dioxide energy storage system dispatching system for power grid peak shaving and valley filling, comprising: The data acquisition module is used to acquire power grid operating status data and carbon dioxide energy storage system operating parameters; The judgment module is used to determine the current power grid load demand status based on the power grid operation status data, and to determine whether the current time period is a peak electricity consumption period or a low electricity consumption period. The energy absorption module is used to determine the energy storage power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system when it is determined that the current period is a low electricity consumption period, and to control the carbon dioxide energy storage system to absorb excess power from the grid through the compression process and convert the power into the internal energy of carbon dioxide for storage. The energy release module is used to determine the energy release power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system when it is determined that the current period is a peak electricity consumption period, and to control the carbon dioxide energy storage system to release the stored carbon dioxide energy, and drive the power generation equipment to output electrical energy to the grid through the expansion process. The adjustment module is used to acquire the operating parameters of the carbon dioxide energy storage system in real time during the energy storage and release processes, and to dynamically adjust the energy storage power or energy release power based on the operating parameters.

[0018] It is understood that the carbon dioxide energy storage system scheduling method and system for peak shaving and valley filling of power grids provided in this application have the same beneficial effects, and will not be described in detail here. Attached Figure Description

[0019] 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 described 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. In the drawings: Figure 1 A flowchart of a carbon dioxide energy storage system scheduling method for power grid peak shaving and valley filling provided in an embodiment of the present invention; Figure 2 This is a functional block diagram of a carbon dioxide energy storage system dispatching system for power grid peak shaving and valley filling, provided in an embodiment of the present invention. Detailed Implementation

[0020] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] In some embodiments of this application, see Figure 1 As shown in the figure, this embodiment provides a method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in power grids, including the following steps: Acquire power grid operation status data and carbon dioxide energy storage system operating parameters; The current power grid load demand status is determined based on the power grid operation status data, and it is determined whether the current time period is a peak electricity consumption period or an off-peak electricity consumption period. When it is determined that the current period is a low electricity consumption period, the energy storage power of the carbon dioxide energy storage system is determined according to the operating parameters of the carbon dioxide energy storage system, and the carbon dioxide energy storage system is controlled to absorb excess power from the grid through the compression process, converting the power into the internal energy of carbon dioxide for storage. When it is determined that the current period is a peak electricity consumption period, the energy release power of the carbon dioxide energy storage system is determined according to the operating parameters of the carbon dioxide energy storage system, and the carbon dioxide energy storage system is controlled to release the stored carbon dioxide energy, and the power generation equipment is driven to output electrical energy to the grid through the expansion process. The system acquires real-time operating parameters of the carbon dioxide energy storage system during the energy storage and release processes, and dynamically adjusts the energy storage power or energy release power based on these operating parameters.

[0022] It is understood that this invention, by acquiring grid operation status data and carbon dioxide energy storage system operating parameters, determines peak or off-peak electricity demand periods based on the current grid load demand status, and controls the carbon dioxide energy storage system to store energy during off-peak periods and release energy during peak periods, thereby achieving peak shaving and valley filling regulation of the grid load. Simultaneously, by acquiring the operating parameters of the carbon dioxide energy storage system in real time during the energy storage and release processes, and dynamically adjusting the energy storage or release power based on these parameters, the carbon dioxide energy storage system can adaptively adjust according to its own operating status and grid load changes. This improves the operational stability of the energy storage system and the grid load regulation capability, reduces the peak-valley difference in the grid, and improves energy utilization efficiency.

[0023] In some specific embodiments of this application, the power grid operation status data includes real-time load power, current time period information, and historical peak-valley time period information; The operating parameters of the carbon dioxide energy storage system include the energy storage tank pressure, energy storage capacity, and carbon dioxide flow rate.

[0024] Understandably, by acquiring power grid operation status data, including real-time load power, current time period information, and historical peak and valley time period information, it is possible to analyze the current power grid operation status from two dimensions: real-time load changes and historical load patterns, thereby improving the accuracy of judging peak and off-peak electricity consumption. Furthermore, by acquiring the operating parameters of the carbon dioxide energy storage system, including the storage tank pressure, storage capacity, and carbon dioxide flow rate, the energy storage status and operating capacity of the energy storage system can be monitored in real time. This provides a data basis for determining the subsequent energy storage power and energy release power, enabling the carbon dioxide energy storage system to be rationally scheduled according to its own operating status, thereby improving the safety and reliability of the energy storage and energy release processes.

[0025] In some specific embodiments of this application, determining the current grid load demand state based on the grid operating status data includes: The real-time load power is compared with the preset load threshold. If the real-time load power is greater than or equal to the preset load threshold, it is preliminarily determined that the current power grid load demand is in a high load state. If the real-time load power is less than the preset load threshold, it is preliminarily determined that the current power grid load demand is in a low load state. Based on the current time period information and historical peak-valley time period information, the current power grid load demand status is determined again: When it is initially determined that the current power grid load demand is in a low load state, check whether the current time period falls within the low valley range in the historical peak and valley time period information. If it is in the low valley range, then the current power grid is finally determined to be in a low load state; if it is not in the low valley range, then the current power grid is finally determined not to be in a low load state. When it is initially determined that the current power grid load demand is in a high load state, check whether the current time period falls within the peak range of the historical peak and valley time period information. If it is in the peak range, then the current power grid is finally determined to be in a high load state; if it is not in a high load state, then the current power grid is finally determined not to be in a high load state.

[0026] Understandably, by comparing real-time load power with preset load thresholds, a preliminary judgment is made on the current grid load demand status. Further judgment is made by combining current time period information and historical peak and valley time period information, avoiding the misjudgment problem caused by relying solely on real-time load power. By comprehensively considering real-time load changes and historical peak and valley patterns, it is possible to more accurately identify whether the current grid is in a high-load or low-load state, providing accurate status basis for subsequent carbon dioxide energy storage system energy storage or energy release scheduling, and improving the reliability and adaptability of grid peak shaving and valley filling scheduling.

[0027] Furthermore, the preset load threshold can be set based on historical power grid operation data. Specifically, real-time load power data within a preset period can be obtained, and the load changes in different time periods can be statistically analyzed. The preset load threshold can be determined based on the lowest load power during historical high load periods or the allowable operating load range of the power grid. At the same time, historical peak and valley period information can be divided according to the power grid load change pattern within the preset period. Periods with consistently high load can be defined as historical peak intervals, and periods with consistently low load can be defined as historical valley intervals, in order to improve the matching degree between the load status judgment results and the actual power grid operation.

[0028] In some specific embodiments of this application, determining whether the current time period is during peak electricity consumption or off-peak electricity consumption includes: When the final determination result is that the current power grid is in a low load state, the current time period is determined to be a low electricity consumption period. When the final determination result is that the current power grid is under high load, it is determined that the current time period is a peak electricity consumption period.

[0029] Understandably, by determining the current electricity consumption status based on the final judgment result of the grid load demand status, the current period is determined as an off-peak electricity consumption period when the current grid is determined to be in a low load state, and as a peak electricity consumption period when the current grid is determined to be in a high load state. This establishes a correspondence between the grid load status and the carbon dioxide energy storage system scheduling process, and can automatically select the energy storage or release mode according to different electricity consumption stages, thereby improving the accuracy and response efficiency of the energy storage system scheduling process.

[0030] In some specific embodiments of this application, when determining that the current period is a low-electricity consumption period, determining the energy storage power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system includes: Obtain the energy storage tank pressure, rated pressure value of the energy storage tank, energy storage capacity, and rated energy storage capacity of the carbon dioxide energy storage system; Calculate the difference between the rated pressure of the energy storage tank and the pressure of the energy storage tank to obtain the remaining pressure of the energy storage tank; Based on the remaining pressure of the energy storage tank and the correspondence between carbon dioxide pressure and stored energy, the remaining storable energy of the current energy storage tank is determined. Calculate the difference between the rated energy storage capacity and the energy storage capacity to obtain the remaining energy storage capacity; The remaining storable energy is compared with the remaining energy storage capacity, and the minimum value between the remaining storable energy and the remaining energy storage capacity is selected as the maximum energy that the carbon dioxide energy storage system can absorb. Obtain the remaining time during the current off-peak electricity period, calculate the ratio of the maximum energy storage capacity to the remaining time, and obtain the maximum energy storage power of the carbon dioxide energy storage system. The maximum energy storage power is compared with the rated power of the compressor, and the minimum value between the maximum energy storage power and the rated power of the compressor is determined as the energy storage power of the carbon dioxide energy storage system.

[0031] Understandably, by obtaining operating parameters of the carbon dioxide energy storage system such as the pressure and capacity of the storage tank, and combining them with the remaining pressure space and remaining energy storage capacity of the storage tank to calculate the maximum absorbable energy of the carbon dioxide energy storage system, and then determining the maximum energy storage power based on the remaining time during the off-peak electricity period, and limiting it in conjunction with the rated power of the compressor, the determined energy storage power can simultaneously meet the requirements of the remaining capacity of the energy storage system and the operating capacity of the equipment. This avoids the problem of equipment overload due to excessive energy storage power or insufficient utilization of off-peak electricity by the grid due to insufficient energy storage power, thereby improving the safety of the carbon dioxide energy storage system's energy storage process and the peak shaving and valley filling effect of the power grid.

[0032] Furthermore, the rated pressure of the energy storage tank, the rated energy storage capacity, and the rated power of the compressor are determined based on the equipment parameters of the carbon dioxide energy storage system.

[0033] Specifically, the rated pressure of the energy storage tank is set according to the pressure bearing capacity of the energy storage tank structure and the safe operating range; the rated energy storage capacity is determined according to the effective volume of the energy storage tank and the maximum carbon dioxide storage capacity; the rated power of the compressor is determined according to the designed operating power of the compressor; the remaining time of the off-peak electricity period is determined according to the time difference between the current time and the pre-divided end time of the off-peak period.

[0034] Specifically, the correspondence between storage tank pressure and stored energy can be obtained through the calibration of the carbon dioxide energy storage system. This involves detecting the corresponding amount of carbon dioxide stored in the storage tank under different storage pressure conditions and establishing a mapping relationship between pressure values ​​and stored energy. After obtaining the difference between the rated pressure value and the current pressure value of the storage tank, the remaining pressure range that the storage tank can still increase is determined based on this remaining pressure value. The amount of carbon dioxide energy that can continue to be stored within this pressure increase range is then calculated using the mapping relationship.

[0035] In some specific embodiments of this application, when determining that the current electricity consumption period is a peak time, determining the energy release power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system includes: Calculate the difference between the pressure of the energy storage tank and the preset minimum working pressure value to obtain the pressure release value of the energy storage tank; Based on the releasable pressure value of the energy storage tank and the correspondence between carbon dioxide pressure and released energy, the releasable energy of the current energy storage tank is determined. Calculate the difference between the energy storage capacity and the preset minimum energy storage capacity to obtain the current remaining releaseable energy storage capacity; Based on the current remaining releaseable energy storage capacity and the energy released per unit mass of carbon dioxide, determine the energy releaseable by the current carbon dioxide energy storage system; The maximum releaseable energy of the carbon dioxide energy storage system is obtained by comparing the releaseable energy of the current energy storage tank with the releaseable energy of the current carbon dioxide energy storage system and selecting the minimum value between the releaseable energy of the current energy storage tank and the releaseable energy of the current carbon dioxide energy storage system. Obtain the remaining time of the current peak electricity consumption period, calculate the ratio of the maximum releaseable energy to the remaining time, and obtain the maximum energy release power of the carbon dioxide energy storage system; The maximum energy release power is compared with the rated power of the expander, and the minimum value between the maximum energy release power and the rated power of the expander is determined as the energy release power of the carbon dioxide energy storage system.

[0036] Understandably, by acquiring the energy storage status of the carbon dioxide energy storage system during peak electricity consumption periods, calculating the maximum releaseable energy based on the release range of the storage tank pressure and the remaining storage capacity, and then determining the maximum release power in conjunction with the remaining time during peak periods, and limiting the release power by the rated power of the expander, the determined release power can simultaneously meet the peak load regulation needs of the power grid and the operational capacity requirements of the carbon dioxide energy storage system. By fully utilizing the stored carbon dioxide pressure energy for energy release and power generation, the peak load pressure on the power grid can be effectively reduced, and the energy utilization efficiency and operational stability of the carbon dioxide energy storage system can be improved.

[0037] Furthermore, the preset minimum working pressure, preset minimum energy storage capacity, and rated power of the expander are determined based on the operating parameters of the carbon dioxide energy storage system equipment.

[0038] The preset minimum working pressure is set according to the minimum pressure required for the energy storage tank and expander to maintain stable operation, so as to avoid the energy release efficiency being reduced due to excessively low carbon dioxide pressure; the preset minimum energy storage capacity is determined according to the minimum energy storage required for continuous operation of the energy storage system, so as to ensure that the system has subsequent adjustment capabilities; the rated power of the expander is determined according to the design operating capacity of the expander.

[0039] Specifically, the relationship between storage tank pressure and released energy is obtained through the calibration of the carbon dioxide energy storage system. This involves detecting the output energy that can be converted during the expansion and release of carbon dioxide under different storage tank pressure conditions, and establishing a mapping relationship between the change in storage tank pressure and the released energy. Once the releaseable value of the storage tank pressure is calculated, the corresponding releaseable energy is determined based on this mapping relationship, which is then used to calculate the maximum energy release power of the carbon dioxide energy storage system.

[0040] In some specific embodiments of this application, the step of acquiring the operating parameters of the carbon dioxide energy storage system in real time during the energy storage and release processes, and dynamically adjusting the energy storage power or energy release power based on the operating parameters, includes: Acquire the energy storage tank pressure, carbon dioxide flow rate, compressor operating power, and expander operating power of the carbon dioxide energy storage system during the energy storage and release processes; Calculate the difference between the energy storage tank pressure at the current detection time and the energy storage tank pressure at the previous detection time to obtain the energy storage tank pressure change; calculate the difference between the carbon dioxide flow rate at the current detection time and the preset target flow rate to obtain the carbon dioxide flow rate deviation value; calculate the difference between the current compressor operating power and the preset energy storage power to obtain the energy storage power deviation value; calculate the difference between the current expander operating power and the preset energy release power to obtain the energy release power deviation value. When the pressure change of the energy storage tank is greater than a preset pressure change threshold, or the carbon dioxide flow deviation is greater than a preset flow deviation threshold, the operating power of the compressor or the operating power of the expander is reduced; when the energy storage power deviation or the energy release power deviation is greater than a preset power deviation threshold, the operating power of the compressor or the operating power of the expander is adjusted according to the energy storage power deviation or the energy release power deviation. The new energy storage power is determined based on the adjusted compressor operating power, or the new energy release power is determined based on the adjusted expander operating power.

[0041] Understandably, by acquiring real-time data on the energy storage tank pressure, carbon dioxide flow rate, compressor operating power, and expander operating power during the operation of the carbon dioxide energy storage system, and by calculating pressure changes, flow rate deviations, and power deviations, it is possible to determine whether the energy storage and release processes deviate from the preset operating state. In the event of pressure fluctuations, abnormal flow rates, or power deviations, the operating power of the compressor or expander can be adjusted in a timely manner, thereby achieving dynamic correction of energy storage and release power. By adjusting the operating state of the energy storage system in real time, the carbon dioxide energy storage system can adapt to changes in grid load, improving the stability of the energy storage system operation and the peak shaving and valley filling effect of the grid.

[0042] Specifically, the preset pressure change threshold, preset target flow rate, preset power deviation threshold, preset energy storage power, and preset energy release power are determined based on the historical operating data and equipment performance parameters of the carbon dioxide energy storage system.

[0043] Among them, the preset pressure change threshold is set according to the safe operating pressure change range of the energy storage tank, the preset target flow rate is determined according to the rated flow rate of the compressor and expander and the system design operating status, the preset power deviation threshold is determined according to the allowable power fluctuation range of the compressor and expander, and the preset energy storage power and preset energy release power are determined according to the current grid load demand and the target operating power calculated by the energy storage system, so as to ensure that the system can be dynamically adjusted within the normal operating range.

[0044] In some specific embodiments of this application, the reduction of compressor operating power or expander operating power and the adjustment of compressor operating power or expander operating power according to the energy storage power deviation value or the energy release power deviation value include: When the pressure change of the energy storage tank is greater than the preset pressure change threshold, the difference between the pressure change of the energy storage tank and the preset pressure change threshold is calculated to obtain the pressure over-limit, and the compressor operating power is reduced according to the pressure over-limit. When the carbon dioxide flow deviation value is greater than the preset flow deviation threshold, the difference between the carbon dioxide flow deviation value and the preset flow deviation threshold is calculated to obtain the flow deviation amount, and the carbon dioxide flow rate is adjusted according to the flow deviation amount; When the energy storage power deviation value is greater than the preset power deviation threshold, the difference between the energy storage power deviation value and the preset power deviation threshold is calculated to obtain the energy storage power adjustment amount, and the compressor operating power is adjusted according to the energy storage power adjustment amount; When the energy release power deviation value is greater than the preset power deviation threshold, the difference between the energy release power deviation value and the preset power deviation threshold is calculated to obtain the energy release power adjustment amount, and the expander operating power is adjusted according to the energy release power adjustment amount.

[0045] It is understood that by calculating the pressure change of the energy storage tank, the deviation value of carbon dioxide flow rate, the deviation value of energy storage power, the deviation value of energy release power and the difference between the corresponding preset thresholds, the specific pressure over-limit, flow deviation and power adjustment amount are obtained. Based on the above adjustment amount, the operating power of the compressor, the operating power of the expander and the carbon dioxide flow rate are adjusted, so that the energy storage process and the energy release process can be finely controlled according to the actual operating deviation. The present invention can reduce the pressure fluctuation and power deviation during the operation of the energy storage system and improve the operating safety and scheduling accuracy of the carbon dioxide energy storage system.

[0046] Furthermore, the preset pressure change threshold, preset flow deviation threshold, and preset power deviation threshold are determined based on the performance parameters of the carbon dioxide energy storage system equipment and its historical operating fluctuation range. The preset pressure change threshold is set according to the allowable pressure change range of the energy storage tank, and is usually less than the safe pressure fluctuation range of the energy storage tank; the preset flow deviation threshold is determined based on the rated flow of the compressor and expander and the flow fluctuation range during normal operation; the preset power deviation threshold is determined based on the rated power of the compressor and expander and the allowable power adjustment range, so that the carbon dioxide energy storage system only adjusts its power when the operating parameters deviate from the normal range, avoiding frequent adjustments that could affect the stable operation of the system.

[0047] In some specific embodiments of this application, determining the new energy storage power based on the adjusted compressor operating power, or determining the new energy release power based on the adjusted expander operating power, includes: Obtain the adjusted compressor operating power and expander operating power; The adjusted compressor operating power is compared with the compressor rated power. If the adjusted compressor operating power is less than or equal to the compressor rated power, the adjusted compressor operating power is determined as the new energy storage power; if the adjusted compressor operating power is greater than the compressor rated power, the compressor rated power is determined as the new energy storage power. The adjusted operating power of the expander is compared with the rated power of the expander. If the adjusted operating power of the expander is less than or equal to the rated power of the expander, the adjusted operating power of the expander is determined as the new energy release power; if the adjusted operating power of the expander is greater than the rated power of the expander, the rated power of the expander is determined as the new energy release power. The energy storage process of the carbon dioxide energy storage system is controlled according to the new energy storage power, or the energy release process of the carbon dioxide energy storage system is controlled according to the new energy release power.

[0048] Understandably, by comparing the adjusted compressor operating power with the compressor's rated power, and comparing the adjusted expander operating power with the expander's rated power, equipment capacity constraints are applied to the adjusted energy storage and release power, ensuring that the final determined energy storage and release power are both within the equipment's allowable operating range. By limiting the adjustment results, overload operation of the compressor or expander due to excessive power adjustment is avoided, thus improving the safety and reliability of the carbon dioxide energy storage system during operation, while also ensuring the stable execution of the grid's peak shaving and valley filling scheduling process.

[0049] Specifically, the rated power of the compressor and the rated power of the expander are determined based on the design parameters of the carbon dioxide energy storage system. The rated power of the compressor is determined based on the compressor's maximum allowable input power, long-term stable operation capability, and manufacturing parameters, while the rated power of the expander is determined based on the expander's maximum allowable output power, mechanical structure load-bearing capacity, and design operating range.

[0050] On the other hand, see Figure 2 As shown, this application also provides a carbon dioxide energy storage system dispatching system for power grid peak shaving and valley filling, used to apply the above-mentioned carbon dioxide energy storage system dispatching method for power grid peak shaving and valley filling, including: The data acquisition module is used to acquire power grid operating status data and carbon dioxide energy storage system operating parameters; The judgment module is used to determine the current power grid load demand status based on the power grid operation status data, and to determine whether the current time period is a peak electricity consumption period or a low electricity consumption period. The energy absorption module is used to determine the energy storage power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system when it is determined that the current period is a low electricity consumption period, and to control the carbon dioxide energy storage system to absorb excess power from the grid through the compression process and convert the power into the internal energy of carbon dioxide for storage. The energy release module is used to determine the energy release power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system when it is determined that the current period is a peak electricity consumption period, and to control the carbon dioxide energy storage system to release the stored carbon dioxide energy, and drive the power generation equipment to output electrical energy to the grid through the expansion process. The adjustment module is used to acquire the operating parameters of the carbon dioxide energy storage system in real time during the energy storage and release processes, and to dynamically adjust the energy storage power or energy release power based on the operating parameters.

[0051] It is understood that this invention achieves automated scheduling and control of the energy storage and release processes of a carbon dioxide energy storage system. Specifically, the acquisition module obtains grid operating status data and energy storage system operating parameters; the judgment module determines the current electricity consumption stage based on grid load status; and the energy absorption module and energy release module control the carbon dioxide energy storage system to store and release energy during off-peak and peak electricity consumption periods, respectively, achieving peak shaving and valley filling of the grid load. Simultaneously, the adjustment module dynamically adjusts the energy storage and release power based on the real-time operating parameters of the energy storage system, enabling the system to adapt to changes in grid load and equipment operating status, thereby improving the accuracy, stability, and energy utilization efficiency of the carbon dioxide energy storage system scheduling.

[0052] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0053] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0054] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0055] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in power grids, characterized in that, include: Acquire power grid operation status data and carbon dioxide energy storage system operating parameters; The current power grid load demand status is determined based on the power grid operation status data, and it is determined whether the current time period is a peak electricity consumption period or an off-peak electricity consumption period. When it is determined that the current period is a low electricity consumption period, the energy storage power of the carbon dioxide energy storage system is determined according to the operating parameters of the carbon dioxide energy storage system, and the carbon dioxide energy storage system is controlled to absorb excess power from the grid through the compression process, converting the power into the internal energy of carbon dioxide for storage. When it is determined that the current period is a peak electricity consumption period, the energy release power of the carbon dioxide energy storage system is determined according to the operating parameters of the carbon dioxide energy storage system, and the carbon dioxide energy storage system is controlled to release the stored carbon dioxide energy, and the power generation equipment is driven to output electrical energy to the grid through the expansion process. The system acquires real-time operating parameters of the carbon dioxide energy storage system during the energy storage and release processes, and dynamically adjusts the energy storage power or energy release power based on these operating parameters.

2. The method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in a power grid according to claim 1, characterized in that, The power grid operation status data includes real-time load power, current time period information, and historical peak and valley time period information; The operating parameters of the carbon dioxide energy storage system include the energy storage tank pressure, energy storage capacity, and carbon dioxide flow rate.

3. The method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in a power grid according to claim 2, characterized in that, Determining the current power grid load demand status based on the power grid operation status data includes: The real-time load power is compared with the preset load threshold. If the real-time load power is greater than or equal to the preset load threshold, it is preliminarily determined that the current power grid load demand is in a high load state. If the real-time load power is less than the preset load threshold, it is preliminarily determined that the current power grid load demand is in a low load state. Based on the current time period information and historical peak-valley time period information, the current power grid load demand status is determined again: When it is initially determined that the current power grid load demand is in a low load state, check whether the current time period falls within the low valley range in the historical peak and valley time period information. If it is in the low valley range, then the current power grid is finally determined to be in a low load state; if it is not in the low valley range, then the current power grid is finally determined not to be in a low load state. When it is initially determined that the current power grid load demand is in a high load state, check whether the current time period falls within the peak range of the historical peak and valley time period information. If it is in the peak range, then the current power grid is finally determined to be in a high load state; if it is not in a high load state, then the current power grid is finally determined not to be in a high load state.

4. The method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in a power grid according to claim 3, characterized in that, The determination of whether the current time period is during peak or off-peak electricity consumption includes: When the final determination result is that the current power grid is in a low load state, the current time period is determined to be a low electricity consumption period. When the final determination result is that the current power grid is under high load, it is determined that the current time period is a peak electricity consumption period.

5. The method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in a power grid according to claim 4, characterized in that, When determining that the current period is a low-demand electricity period, the method of determining the energy storage capacity of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system includes: Obtain the energy storage tank pressure, rated pressure value of the energy storage tank, energy storage capacity, and rated energy storage capacity of the carbon dioxide energy storage system; Calculate the difference between the rated pressure of the energy storage tank and the pressure of the energy storage tank to obtain the remaining pressure of the energy storage tank; Based on the remaining pressure of the energy storage tank and the correspondence between carbon dioxide pressure and stored energy, the remaining storable energy of the current energy storage tank is determined. Calculate the difference between the rated energy storage capacity and the energy storage capacity to obtain the remaining energy storage capacity; The remaining storable energy is compared with the remaining energy storage capacity, and the minimum value between the remaining storable energy and the remaining energy storage capacity is selected as the maximum energy that the carbon dioxide energy storage system can absorb. Obtain the remaining time during the current off-peak electricity period, calculate the ratio of the maximum energy storage capacity to the remaining time, and obtain the maximum energy storage power of the carbon dioxide energy storage system. The maximum energy storage power is compared with the rated power of the compressor, and the minimum value between the maximum energy storage power and the rated power of the compressor is determined as the energy storage power of the carbon dioxide energy storage system.

6. The method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in a power grid according to claim 5, characterized in that, When determining that the current electricity consumption period is a peak time, the step of determining the energy release power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system includes: Calculate the difference between the pressure of the energy storage tank and the preset minimum working pressure value to obtain the pressure release value of the energy storage tank; Based on the releasable pressure value of the energy storage tank and the correspondence between carbon dioxide pressure and released energy, the releasable energy of the current energy storage tank is determined. Calculate the difference between the energy storage capacity and the preset minimum energy storage capacity to obtain the current remaining releaseable energy storage capacity; Based on the current remaining releaseable energy storage capacity and the energy released per unit mass of carbon dioxide, determine the energy releaseable by the current carbon dioxide energy storage system; The maximum releaseable energy of the carbon dioxide energy storage system is obtained by comparing the releaseable energy of the current energy storage tank with the releaseable energy of the current carbon dioxide energy storage system and selecting the minimum value between the releaseable energy of the current energy storage tank and the releaseable energy of the current carbon dioxide energy storage system. Obtain the remaining time of the current peak electricity consumption period, calculate the ratio of the maximum releaseable energy to the remaining time, and obtain the maximum energy release power of the carbon dioxide energy storage system; The maximum energy release power is compared with the rated power of the expander, and the minimum value between the maximum energy release power and the rated power of the expander is determined as the energy release power of the carbon dioxide energy storage system.

7. The method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in a power grid according to claim 6, characterized in that, The process of acquiring real-time operating parameters of the carbon dioxide energy storage system during the energy storage and release processes, and dynamically adjusting the energy storage power or energy release power based on the operating parameters, includes: Acquire the energy storage tank pressure, carbon dioxide flow rate, compressor operating power, and expander operating power of the carbon dioxide energy storage system during the energy storage and release processes; Calculate the difference between the energy storage tank pressure at the current detection time and the energy storage tank pressure at the previous detection time to obtain the energy storage tank pressure change; calculate the difference between the carbon dioxide flow rate at the current detection time and the preset target flow rate to obtain the carbon dioxide flow rate deviation value; calculate the difference between the current compressor operating power and the preset energy storage power to obtain the energy storage power deviation value; calculate the difference between the current expander operating power and the preset energy release power to obtain the energy release power deviation value. When the pressure change of the energy storage tank is greater than a preset pressure change threshold, or the carbon dioxide flow deviation is greater than a preset flow deviation threshold, the operating power of the compressor or the operating power of the expander is reduced; when the energy storage power deviation or the energy release power deviation is greater than a preset power deviation threshold, the operating power of the compressor or the operating power of the expander is adjusted according to the energy storage power deviation or the energy release power deviation. The new energy storage power is determined based on the adjusted compressor operating power, or the new energy release power is determined based on the adjusted expander operating power.

8. The method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in a power grid according to claim 7, characterized in that, When reducing the operating power of the compressor or expander and adjusting the operating power of the compressor or expander according to the energy storage power deviation value or the energy release power deviation value, the following are included: When the pressure change of the energy storage tank is greater than the preset pressure change threshold, the difference between the pressure change of the energy storage tank and the preset pressure change threshold is calculated to obtain the pressure over-limit, and the compressor operating power is reduced according to the pressure over-limit. When the carbon dioxide flow deviation value is greater than the preset flow deviation threshold, the difference between the carbon dioxide flow deviation value and the preset flow deviation threshold is calculated to obtain the flow deviation amount, and the carbon dioxide flow rate is adjusted according to the flow deviation amount; When the energy storage power deviation value is greater than the preset power deviation threshold, the difference between the energy storage power deviation value and the preset power deviation threshold is calculated to obtain the energy storage power adjustment amount, and the compressor operating power is adjusted according to the energy storage power adjustment amount; When the energy release power deviation value is greater than the preset power deviation threshold, the difference between the energy release power deviation value and the preset power deviation threshold is calculated to obtain the energy release power adjustment amount, and the expander operating power is adjusted according to the energy release power adjustment amount.

9. The method for scheduling a carbon dioxide energy storage system for peak shaving and valley filling in a power grid according to claim 8, characterized in that, When determining the new energy storage power based on the adjusted compressor operating power, or the new energy release power based on the adjusted expander operating power, the following is included: Obtain the adjusted compressor operating power and expander operating power; The adjusted compressor operating power is compared with the compressor rated power. If the adjusted compressor operating power is less than or equal to the compressor rated power, the adjusted compressor operating power is determined as the new energy storage power; if the adjusted compressor operating power is greater than the compressor rated power, the compressor rated power is determined as the new energy storage power. The adjusted operating power of the expander is compared with the rated power of the expander. If the adjusted operating power of the expander is less than or equal to the rated power of the expander, the adjusted operating power of the expander is determined as the new energy release power; if the adjusted operating power of the expander is greater than the rated power of the expander, the rated power of the expander is determined as the new energy release power. The energy storage process of the carbon dioxide energy storage system is controlled according to the new energy storage power, or the energy release process of the carbon dioxide energy storage system is controlled according to the new energy release power.

10. A carbon dioxide energy storage system dispatching system for power grid peak shaving and valley filling, used to apply the carbon dioxide energy storage system dispatching method for power grid peak shaving and valley filling as described in any one of claims 1-9, characterized in that, include: The data acquisition module is used to acquire power grid operating status data and carbon dioxide energy storage system operating parameters; The judgment module is used to determine the current power grid load demand status based on the power grid operation status data, and to determine whether the current time period is a peak electricity consumption period or a low electricity consumption period. The energy absorption module is used to determine the energy storage power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system when it is determined that the current period is a low electricity consumption period, and to control the carbon dioxide energy storage system to absorb excess power from the grid through the compression process and convert the power into the internal energy of carbon dioxide for storage. The energy release module is used to determine the energy release power of the carbon dioxide energy storage system based on the operating parameters of the carbon dioxide energy storage system when it is determined that the current period is a peak electricity consumption period, and to control the carbon dioxide energy storage system to release the stored carbon dioxide energy, and drive the power generation equipment to output electrical energy to the grid through the expansion process. The adjustment module is used to acquire the operating parameters of the carbon dioxide energy storage system in real time during the energy storage and release processes, and to dynamically adjust the energy storage power or energy release power based on the operating parameters.

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