A method and system for coordinated control of peak shaving and valley filling in energy storage power stations

Abstract

The present invention belongs to the field of energy storage power station control technology, and specifically relates to a method and system for coordinated control of peak shaving and valley filling in energy storage power stations. The method includes the integration of peak shaving and valley filling, precise demand control and effective backflow prevention functions. According to the preset plan of peak shaving and valley filling, the charging or discharging period is intelligently judged, and the grid interaction power, protocol demand and current state of energy storage are monitored in real time. When charging, the optimal charging power is set through careful comparison to avoid excess charges; when discharging, the backflow risk is strictly controlled and the discharge strategy is optimized. The present invention not only effectively smoothes out grid load fluctuations, but also significantly improves the economic operation efficiency and cost-effectiveness of energy storage power stations, providing strong support for flexible scheduling and intelligent management of energy systems.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage power station control, and particularly relates to a peak shaving and valley filling coordinated control method and system for an energy storage power station. Background Art

[0002] Peak shaving and valley filling is currently the main operating mode and profit model of user-side energy storage power stations. Peak shaving and valley filling refers to the energy storage system purchasing electricity from the grid and storing it in the energy storage system during low-load and low-electricity-price periods, and discharging the previously stored electricity to supply the required electricity during high-load and high-electricity-price periods, avoiding the direct large-scale use of high-priced grid electricity. This can not only alleviate the power supply pressure of the grid during peak electricity consumption periods, maintain stable operation of the grid load, and improve the grid utilization rate during low electricity consumption periods, but also help energy storage users achieve peak-valley electricity price arbitrage, creating considerable economic benefits for energy storage users.

[0003] However, there are also some problems with the energy storage system during peak shaving and valley filling operation. For example, when the energy storage system is discharging, if the total power consumption of the user is less than the discharge power of the energy storage system, the power of the energy storage system will flow back into the upper power grid, which will not only reduce the peak shaving and valley filling income of the energy storage system, but also cause grid fluctuations, affect the safe operation of the grid, and cause damage to personnel and equipment; or when the energy storage system is charging, if the charging power is too large, resulting in excessive total power consumption of the user, not only will the user's transformer be overloaded or even tripped, affecting the transformer's life and power safety, but also incur additional high electricity costs due to exceeding the agreed demand. Summary of the Invention

[0004] The purpose of the present invention is to provide a peak shaving and valley filling coordinated control method and system for an energy storage power station to solve the problems raised in the background technology.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] In a first aspect, the present invention proposes a peak shaving and valley filling coordinated control method for an energy storage power station, the method comprising:

[0007] Get the current planned value P for peak shaving and valley filling plan , according to P plan The positive or negative value of determines whether the current period is charging or discharging;

[0008] During the charging period, according to the current grid power P pcc and the agreed demand P dm The comparison results, combined with the current power P of the energy storage ess and the planned value P plan The target power P is determined by the relationship tar , according to the target power P tar1 Control the energy storage converter to charge;

[0009] During the discharge period, according to the current grid-connected power P pcc and anti-backflow protection threshold P rpp The comparison results, combined with the current power P of the energy storage ess and planned value P plan The target power P is determined by the relationship tar2 , according to the target power P tar2 Control the energy storage converter to discharge.

[0010] Furthermore, the peak shaving and valley filling plan value and energy storage power are defined according to the principle that charging power is a negative number and discharging power is a positive number; the grid connection point power is defined according to the principle that electric energy absorbed from the grid is a positive number and electric energy output to the grid is a negative number.

[0011] Furthermore, during the charging period, if the grid power P pcc +Current power of energy storage P ess -Planned value P plan >Agreement demand P dm , then set the target power P tar1 =Grid connection point power P pcc +Current power of energy storage P ess -Agreement demand P dm , further determine the target power P tar1 Is it greater than zero? If it is greater than zero, set it to P tar1 =0, otherwise further determine the target power P tar1 Is it greater than the current maximum allowed charging power P? lowLmt If so, maintain the target power P tar1 unchanged, otherwise set the target power P tar1 = the current maximum allowed charging power P lowLmt .

[0012] Furthermore, during the discharge period, if the grid-connected point power P pcc +Current power of energy storage P ess -Planned value P plan < Anti-backflow protection threshold P rpp , then set the target power P tar2 =Grid connection point power P pcc +Current power of energy storage P ess - Anti-backflow protection threshold P rpp , further determine the target power P tar2 Is it less than zero? If it is less than zero, set it to P tar2 =0, otherwise further determine the target power P tar2 Is it less than the current maximum allowed discharge power P? upLmt If so, maintain the target power Ptar2 unchanged, otherwise set the target power P tar2 =The maximum discharge power allowed at present P upLmt .

[0013] Furthermore, the method further includes: based on the set peak shaving and valley filling plan value P plan Determine the energy storage system as a standby period, including: if the planned value P plan =0, judge that the current period is standby, set the target power P tar3 =0, the energy storage system is in zero power standby state.

[0014] In a second aspect, the present invention further proposes a peak-shaving and valley-filling coordinated control system for an energy storage power station, which is applied to execute any of the above-mentioned coordinated control methods. The coordinated control system includes:

[0015] The judgment module is used to receive the peak shaving and valley filling plan value set by the user, and plan The positive or negative value of determines whether the current period is charging or discharging;

[0016] Grid connection point monitoring equipment, used to measure the current grid connection point power in real time;

[0017] The first control module is used to control the current grid power P during the charging period. pcc and the agreed demand P dm The comparison results, combined with the current power P of the energy storage ess and the planned value P plan The target power P is determined by the relationship tar , and issue control instructions;

[0018] The second control module is used to control the current grid power P during the discharge period. pcc and anti-backflow protection threshold P rpp The comparison results, combined with the current power P of the energy storage ess and the planned value P plan The target power P is determined by the relationship tar2 , and issue control instructions;

[0019] The energy storage converter is used to receive and respond to the control instructions to perform charge and discharge control.

[0020] Furthermore, the collaborative control system further includes a third control module, and the judgment module is further configured to determine the peak shaving and valley filling plan value P based on the set peak shaving and valley filling plan value P. plan Determine that the energy storage system is in the standby period, the third control module is used to set the planned value P plan =0, it is determined that the current period is standby, and the target power P is set. tar3 =0, the energy storage system is in zero power standby state.

[0021] Furthermore, the first control module, the second control module and the third control module all include a data processing unit and an instruction output unit. The data processing unit is used to calculate the target charge and discharge power of the energy storage system, and the instruction output unit is used to send control instructions to the energy storage converter.

[0022] Furthermore, the collaborative control system also includes a monitoring module for recording system operation logs and providing abnormal alarm functions.

[0023] The beneficial effects of the present invention are:

[0024] The collaborative control method proposed in this invention automatically adjusts the charge and discharge power of the energy storage converter in real time based on the user-defined peak-valley arbitrage plan, combined with constraints such as the PCS real-time maximum charge and discharge power limit, as well as transformer protocol demand control and grid-connected reverse power protection limits. This achieves peak shaving and valley filling, as well as peak-valley arbitrage, while avoiding situations where exceeding the protocol demand would result in high electricity bills or reverse transmission of stored energy power to the grid. The control strategy of this invention is simple, computationally fast, and highly practical, making it highly valuable for practical engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a flow chart of a collaborative control method provided in an embodiment of the present application;

[0026] Figure 2 Another flowchart of the collaborative control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The present application is described in further detail below in conjunction with the accompanying drawings. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0028] Example 1

[0029] like Figure 1-2 As shown, this embodiment proposes a peak shaving and valley filling coordinated control method for an energy storage power station, the method comprising:

[0030] Get the current planned value P for peak shaving and valley filling plan , according to P plan The positive or negative value of determines whether the current period is charging or discharging;

[0031] During the charging period, according to the current grid power P pcc and the agreed demand P dm The comparison results, combined with the current power P of the energy storageess and planned value P plan The target power P is determined by the relationship tar , according to the target power P tar1 Control the energy storage converter to charge;

[0032] During the discharge period, according to the current grid-connected power P pcc and anti-backflow protection threshold P rpp The comparison results, combined with the current power P of the energy storage ess and planned value P plan The target power P is determined by the relationship tar2 , according to the target power P tar2 Control the power storage converter (PCS) to discharge.

[0033] Further preferably, the peak shaving and valley filling plan value and the energy storage power are defined according to the principle that the charging power is a negative number and the discharging power is a positive number; the grid connection point power is defined according to the principle that the electric energy absorbed from the grid is a positive number and the electric energy output to the grid is a negative number.

[0034] Further preferably, during the charging period, if the grid power P pcc +Current power of energy storage P ess -Planned value P plan >Agreement demand P dm , then set the target power P tar1 =Grid connection point power P pcc +Current power of energy storage P ess -Agreement demand P dm , further determine the target power P tar1 Is it greater than zero? If it is greater than zero, set it to P tar1 =0, otherwise further determine the target power P tar1 Is it greater than the current maximum allowed charging power P? lowLmt If so, maintain the target power P tar1 unchanged, otherwise set the target power P tar1 = the current maximum allowed charging power P lowLmt .

[0035] Further preferably, during the discharge period, if the grid power P pcc +Current power of energy storage P ess -Planned value P plan < Anti-backflow protection threshold P rpp , then set the target power P tar2 =Grid connection point power P pcc +Current power of energy storage P ess - Anti-backflow protection threshold P rpp , further determine the target power P tar2Is it less than zero? If it is less than zero, set it to P tar2 =0, otherwise further determine the target power P tar2 Is it less than the current maximum allowed discharge power P? upLmt If so, maintain the target power P tar2 unchanged, otherwise set the target power P tar2 =The maximum discharge power allowed at present P upLmt .

[0036] Further preferably, the method further includes: based on the set peak shaving and valley filling plan value P plan Determine the energy storage system as a standby period, including: if the planned value P plan =0, judge that the current period is standby, set the target power P tar3 =0, the energy storage system is in zero power standby state.

[0037] In this embodiment, the core of the coordinated control method for peak-shaving and valley-filling of energy storage power stations lies in the use of intelligent control strategies to enable the energy storage power station to flexibly adjust its charging and discharging behavior based on the real-time needs of the power grid and the preset peak-shaving and valley-filling plan, thereby optimizing the power grid load and improving energy utilization efficiency. The following are the specific implementation steps and principles of this method:

[0038] Plan value acceptance and time period judgment:

[0039] Steps: The system first receives the current time plan value P for peak shaving and valley filling set by the user or the dispatching system. plan .

[0040] Judgment: According to P plan The positive or negative value of the current charging period (P plan is negative) or discharge period (P plan is positive).

[0041] Charging period control:

[0042] Monitoring: Real-time acquisition of grid-connected power P pcc and the current power of energy storage P ess .

[0043] Calculation: Calculate P pcc +P ess -P plan and the agreed demand P dm The comparison results.

[0044] Target power setting:

[0045] If P pcc +P ess -P plan >P dm , then set the target power P according to the constraint conditionstar1 If P tar1 If the calculated value is greater than 0, it is limited to 0 to avoid false discharge; otherwise, the target power P is further determined. tar1 Is it greater than the current maximum allowed charging power P? lowLmt If so, maintain the target power P tar1 unchanged, otherwise set the target power P tar1 = the current maximum allowed charging power P lowLmt .

[0046] Control: According to P tar1 Control the energy storage converter to charge.

[0047] Discharge period control:

[0048] Monitoring: Also obtain P in real time pcc and P ess .

[0049] Calculation: Calculate P pcc +P ess -P plan and anti-backflow protection threshold P rpp The comparison results.

[0050] Target power setting:

[0051] If P pcc +P ess -P plan <P rpp , then set the target power P according to the constraint conditions tar2 If P tar2 If the calculated value is less than 0, it is limited to 0 to avoid mischarging; otherwise, the target power P is further determined. tar2 Is it less than the current maximum allowed discharge power P? upLmt If so, maintain the target power P tar2 unchanged, otherwise set the target power P tar2 =The maximum discharge power allowed at present P upLmt .

[0052] Control: According to P tar2 Control the energy storage converter to discharge.

[0053] Standby period control:

[0054] Judgment: If P plan =0, it is determined that the current period is the standby period.

[0055] Control: Set target power P tar3 =0, the energy storage system is in zero power standby state.

[0056] According to the above embodiment, by intelligently determining the current time period (charging, discharging, or standby), and based on real-time grid demand, energy storage status, and preset plans, the charging and discharging power of the energy storage power station is accurately calculated and controlled. This method not only effectively balances the grid load, but also avoids adverse conditions such as overcharging and reverse flow through sophisticated power management strategies, ensuring the safe and stable operation of the energy storage system. In addition, by clarifying the positive and negative definitions and constraints of power, the practicality and reliability of the control method are further improved, providing strong support for intelligent grid management and efficient energy utilization.

[0057] Based on the same inventive concept, this embodiment also proposes a peak-shaving and valley-filling coordinated control system for an energy storage power station, which is applied to execute the above-mentioned coordinated control method. The coordinated control system includes:

[0058] The judgment module is used to receive the peak shaving and valley filling plan value set by the user, and plan The positive or negative value of determines whether the current period is charging or discharging;

[0059] Grid connection point monitoring equipment, used to measure the current grid connection point power in real time;

[0060] The first control module is used to control the current grid power P during the charging period. pcc and the agreed demand P dm The comparison results, combined with the current power P of the energy storage ess and the planned value P plan The target power P is determined by the relationship tar , and issue control instructions;

[0061] The second control module is used to control the current grid power P during the discharge period. pcc and anti-backflow protection threshold P rpp The comparison results, combined with the current power P of the energy storage ess and the planned value P plan The target power P is determined by the relationship tar2 , and issue control instructions;

[0062] The energy storage converter is used to receive and respond to control instructions to perform charge and discharge control.

[0063] The energy storage power station peak shaving and valley filling coordinated control system of the present invention aims to realize the charging and discharging management of the energy storage power station efficiently and accurately through an integrated module design, so as to achieve the purpose of balancing the grid load and improving energy utilization efficiency.

[0064] It should be noted here that each module in the above-mentioned collaborative control system corresponds to each step in implementing the above-mentioned collaborative control method, and the instances and application scenarios implemented by multiple modules and corresponding steps are the same, but are not limited to the contents disclosed in the above-mentioned embodiment 1.

[0065] Further preferably, the collaborative control system further includes a third control module, and the judgment module is further configured to determine the peak shaving and valley filling plan value P based on the set peak shaving and valley filling plan value P. plan Determine that the energy storage system is in the standby period, and the third control module is used to set the planned value P plan =0, it is determined that the current period is standby, and the target power P is set. tar3 =0, the energy storage system is in zero power standby state.

[0066] Further preferably, the first control module, the second control module and the third control module all include a data processing unit and an instruction output unit, the data processing unit is used to calculate the target charge and discharge power of the energy storage system, and the instruction output unit is used to send control instructions to the energy storage converter.

[0067] Further preferably, the collaborative control system also includes a monitoring module for recording system operation logs and providing abnormal alarm functions.

[0068] It is understandable that the collaborative control system integrates intelligent judgment, real-time monitoring, and precise control functions through modular design. The judgment module determines the charge and discharge mode based on the planned value set by the user, and the grid monitoring equipment provides real-time feedback of the grid status to the control module. The first and second control modules calculate the target power during the charge and discharge period based on the grid demand and energy storage status, and send control instructions to the energy storage converter for execution. The third control module maintains a zero power state during the standby period. The monitoring module records the operating status throughout the process to ensure system safety and stability. The modules work closely together to achieve efficient charge and discharge management of the energy storage power station, effectively balance the grid load, and improve energy utilization efficiency.

[0069] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0070] In addition, the functional modules in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0071] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0072] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements 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 application.

Claims

1. A peak shaving and valley filling coordinated control method for an energy storage power station, characterized in that: The method comprises: Get the current peak shaving and valley filling plan value P plan , according to P plan The positive or negative value of determines whether the current period is charging or discharging; During the charging period, according to the current grid power P pcc and the agreed demand P dm The comparison results, combined with the current power P of the energy storage ess and planned value P plan The target power P is determined by the relationship tar , according to the target power P tar1 Control the energy storage converter to charge; During the discharge period, according to the current grid-connected power P pcc and anti-backflow protection threshold P rpp The comparison results, combined with the current power P of the energy storage ess and planned value P plan The target power P is determined by the relationship tar2 , according to the target power P tar2 Control the energy storage converter to discharge; During the charging period, if the grid power P pcc +Current power of energy storage P ess - Planned value P plan >Agreement demand P dm , then set the target power P tar1 =Grid connection point power P pcc +Current power of energy storage P ess - Agreement demand P dm , further determine the target power P tar1 Is it greater than zero? If it is greater than zero, set it to P tar1 = 0, otherwise further determine the target power P tar1 Is it greater than the maximum charging power P? lowLmt , if so, maintain the target power P tar1 unchanged, otherwise set the target power P tar1 = the current maximum allowed charging power P lowLmt ; During the discharge period, if the grid-connected point power P pcc +Current power of energy storage P ess - Planned value P plan < Anti-backflow protection threshold P rpp , then set the target power P tar2 = Grid connection point power P pcc + Energy storage current power P ess - Anti-backflow protection threshold P rpp , further determine the target power P tar2 Is it less than zero? If it is less than zero, set it to P tar2 = 0, otherwise further determine the target power P tar2 Is it less than the current maximum allowed discharge power P? upLmt If so, keep P tar2 unchanged, otherwise set the target power P tar2 =The maximum discharge power allowed at present P upLmt .

2. A peak shaving and valley filling coordinated control method for an energy storage power station according to claim 1, characterized in that: The peak shaving and valley filling planned value and energy storage power are defined according to the principle that charging power is a negative number and discharging power is a positive number; the grid connection point power is defined according to the principle that electric energy absorbed from the grid is a positive number and electric energy output to the grid is a negative number.

3. The peak shaving and valley filling coordinated control method for an energy storage power station according to claim 1, characterized in that: The method further includes: based on the set peak shaving and valley filling plan value P plan Determine the energy storage system as a standby period, including: if the planned value P plan =0, judge that the current period is standby, set the target power P tar3 = 0, the energy storage system is in zero power standby state.

4. A peak shaving and valley filling coordinated control system for an energy storage power station, applied to execute the coordinated control method according to any one of claims 1 to 3, characterized in that: The collaborative control system includes: The judgment module is used to receive the peak shaving and valley filling plan value P set by the user plan , according to P plan The positive or negative value of determines whether the current period is charging or discharging; Grid connection point monitoring equipment, used to measure the current grid connection point power in real time; The first control module is used to control the current grid power P during the charging period. pcc and the agreed demand P dm The comparison results, combined with the current power P of the energy storage ess and planned value P plan The target power P is determined by the relationship tar , and issue control instructions; The second control module is used to control the current grid power P during the discharge period. pcc and anti-backflow protection threshold P rpp The comparison results, combined with the current power P of the energy storage ess and planned value P plan The target power P is determined by the relationship tar2 , and issue control instructions; The energy storage converter is used to receive and respond to the control instructions to perform charge and discharge control.

5. The energy storage power station peak shaving and valley filling coordinated control system according to claim 4, characterized in that: The collaborative control system further includes a third control module, and the judgment module is further configured to determine the peak shaving and valley filling plan value P based on the set peak shaving and valley filling plan value P. plan Determine that the energy storage system is in the standby period, the third control module is used to set the planned value P plan = 0, it is determined that the current period is standby, and the target power P is set. tar3 = 0, the energy storage system is in zero power standby state.

6. The energy storage power station peak shaving and valley filling coordinated control system according to claim 5, characterized in that: The first control module, the second control module and the third control module all include a data processing unit and an instruction output unit. The data processing unit is used to calculate the target charge and discharge power of the energy storage system, and the instruction output unit is used to send control instructions to the energy storage converter.

7. The energy storage power station peak shaving and valley filling coordinated control system according to claim 4, characterized in that: The collaborative control system also includes a monitoring module for recording system operation logs and providing abnormal alarm functions.

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