Energy storage power station peak load shifting cooperative control method and system

Abstract

The invention belongs to the technical field of energy storage power station control, and particularly relates to a peak clipping and valley filling cooperative control method and system for an energy storage power station, and the method integrates peak clipping and valley filling, precise demand control and effective countercurrent prevention functions. According to a preset plan of peak load shifting, charging or discharging time periods are intelligently judged, and the interaction power, the protocol demand and the current energy storage state of a power grid are monitored in real time. During charging, the optimal charging power is set through fine comparison so as to avoid excess cost; and during discharging, the countercurrent risk is strictly prevented and controlled, and the discharging strategy is optimized. According to the method, the load fluctuation of the power grid is effectively stabilized, the economic operation efficiency and the cost effectiveness of the energy storage power station are remarkably improved, and powerful support is provided for flexible scheduling and intelligent management of an energy system.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage power station control, and in particular 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 power 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 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 the 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 in the process of peak shaving and valley filling operation of energy storage systems. For example, when the energy storage system is discharging, if the total power consumption of users is less than the discharge power of the energy storage system, the electric energy 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 users, which will not only cause the user's transformer to overload or even trip, affecting the life of the transformer 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 period or discharging period;

[0008] During the charging period, according to the current grid power P pcc Agreement demand P dm The comparison results, combined with the current power P of the energy storage ess With the planned value P plan The target power P is determined by tar , according to the target power P tar1 Controlling 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 With the planned value P plan The target power P is determined by 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 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.

[0011] Furthermore, during the charging period, if the grid-connected point power P pcc + Energy storage current power P ess -Planned value P plan >Agreement demand P dm , then set the target power P tar1 =Grid connection point power P pcc + Energy storage current power 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 maximum charging power currently allowed P lowLmt .

[0012] Furthermore, during the discharge period, if the grid-connected point power P pcc + Energy storage current power 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, 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, putting the energy storage system 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, and 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 period or discharging period;

[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-connected point power P during the charging period. pcc Agreement demand P dm The comparison results, combined with the current power P of the energy storage ess With the planned value P plan The target power P is determined by tar , and issue control instructions;

[0018] The second control module is used to control the current grid-connected point 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 With the planned value P plan The target power P is determined by tar2 , and issue control instructions;

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

[0020] Furthermore, the collaborative control system further includes a third control module, and the judgment module is further used to determine the peak load reduction and valley filling plan value P based on the set peak load reduction and valley filling plan value P. plan Determine that the energy storage system is in a standby period, and the third control module is used to set the planned value P plan =0, it is judged that the current period is standby, and the target power P is set tar3 =0, putting the energy storage system 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 charging and discharging power of the energy storage system, and the instruction output unit is used to send control instructions to the energy storage inverter.

[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 the present invention can automatically adjust the charge and discharge power of the energy storage converter in real time according to the peak-valley arbitrage plan set by the user, combined with the constraints such as the real-time maximum charge and discharge power limit of the PCS, as well as the transformer protocol demand control and the grid-connected reverse power protection limit, so as to achieve peak shaving and valley filling and peak-valley arbitrage while avoiding the situation of exceeding the protocol demand and incurring high electricity bills or the situation of reverse transmission of energy storage power to the power grid. The control strategy of the present invention is simple, the calculation speed is fast, the practicability is strong, and it has high application value in engineering practice. 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 the embodiment of the present application. DETAILED DESCRIPTION

[0027] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here 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. Technical personnel 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 period or discharging period;

[0031] During the charging period, according to the current grid power P pcc Agreement demand P dm The comparison results, combined with the current power P of the energy storageess With the planned value P plan The target power P is determined by tar , according to the target power P tar1 Controlling 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 With the planned value P plan The target power P is determined by 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 + Energy storage current power P ess -Planned value P plan >Agreement demand P dm , then set the target power P tar1 =Grid connection point power P pcc + Energy storage current power 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 maximum charging power currently allowed P lowLmt .

[0035] Further preferably, during the discharge period, if the grid-connected power P pcc + Energy storage current power 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 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 comprises: 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, putting the energy storage system 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 is to enable the energy storage power stations to flexibly adjust their charging and discharging behaviors according to the real-time needs of the power grid and the preset peak-shaving and valley-filling plan through intelligent control strategies, so as to optimize the power grid load and improve energy utilization efficiency. The following are the specific implementation steps and principles of the 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 determines whether the current charging period is (P plan is negative) or the discharge period (P plan is positive).

[0041] Charging period control:

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

[0043] Calculation: Calculate P pcc +P ess -P plan Agreement 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 mis-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 maximum charging power currently allowed 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 judged that the current period is the standby period.

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

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

[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 period or discharging period;

[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-connected point power P during the charging period. pcc Agreement demand P dm The comparison results, combined with the current power P of the energy storage ess With the planned value P plan The target power P is determined by tar , and issue control instructions;

[0061] The second control module is used to control the current grid-connected point 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 With the planned value P plan The target power P is determined by 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 load reduction and valley filling plan value P based on the set peak load reduction 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 judged that the current period is standby, and the target power P is set tar3 =0, putting the energy storage system 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 charging and discharging 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 in the collaborative control system, functions such as intelligent judgment, real-time monitoring, and precise control are integrated through modular design. The judgment module determines the charging and discharging mode according to the planned value set by the user, and the grid monitoring equipment feeds back the grid status to the control module in real time. The first and second control modules calculate the target power during the charging and discharging period based on the grid demand and energy storage status, and send control instructions to the energy storage inverter 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 the safety and stability of the system. The modules work closely together to achieve efficient charging and discharging management of the energy storage power station, effectively balance the grid load, and improve energy utilization efficiency.

[0069] Those of ordinary skill 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 to be beyond the scope of this application.

[0070] In addition, each functional module in each embodiment 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 can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform 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 it. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. 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 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 period or discharging period; During the charging period, according to the current grid power P pcc Agreement demand P dm The comparison results, combined with the current power P of the energy storage ess With the planned value P plan The target power P is determined by tar , according to the target power P tar1 Controlling 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 With the planned value P plan The target power P is determined by tar2 , according to the target power P tar2 Control the energy storage converter to discharge.

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 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.

3. A peak shaving and valley filling coordinated control method for an energy storage power station according to claim 1, characterized in that: During the charging period, if the grid power P pcc + Energy storage current power P ess -Planned value P plan >Agreement demand P dm , then set the target power P tar1 =Grid connection point power P pcc + Energy storage current power 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 maximum charging power currently allowed P lowLmt .

4. A peak shaving and valley filling coordinated control method for an energy storage power station according to claim 1, characterized in that: During the discharge period, if the grid-connected power P pcc + Energy storage current power 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 .

5. The peak shaving and valley filling coordinated control method of 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, putting the energy storage system in zero power standby state.

6. 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 5, characterized in that: The collaborative control system comprises: 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 period or discharging period; 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-connected point power P during the charging period. pcc Agreement demand P dm The comparison results, combined with the current power P of the energy storage ess With the planned value P plan The target power P is determined by tar , and issue control instructions; The second control module is used to control the current grid-connected point 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 With the planned value P plan The target power P is determined by tar2 , and issue control instructions; The energy storage converter is used to receive and respond to the control instruction to perform charge and discharge control.

7. A peak shaving and valley filling coordinated control system for energy storage power stations according to claim 6, characterized in that: The collaborative control system further includes a third control module, wherein the judgment module is further configured to determine the peak load reduction and valley filling plan value P based on the set peak load reduction and valley filling plan value P. plan Determine that the energy storage system is in a standby period, and the third control module is used to set the planned value P plan =0, it is judged that the current period is standby, and the target power P is set tar3 =0, putting the energy storage system in zero power standby state.

8. A peak shaving and valley filling coordinated control system for energy storage power stations according to claim 7, 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 charging and discharging power of the energy storage system, and the instruction output unit is used to send control instructions to the energy storage converter.

9. A peak shaving and valley filling coordinated control system for energy storage power stations according to claim 6, 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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