Energy storage participation section control method and system

Abstract

The invention relates to an energy storage participation section control method, which is characterized by comprising the following steps of: mounting an energy storage station under a section, and detecting a section load rate; when the energy storage section load rate is higher than a first load rate threshold, the energy storage station is prohibited from discharging, the energy storage section adjusting quantity is calculated, and a discharging instruction is distributed to the energy storage station according to a distribution strategy until the section adjusting requirement is met; when the load rate of the energy storage section is between the first load rate threshold and the second load rate threshold, the discharged energy storage station maintains the current active power unchanged; and when the energy storage section load rate is lower than a second load rate threshold, the energy storage power station performs charging and discharging after energy storage instruction verification according to the self-use instruction value, the plan value and the peak regulation target which are uploaded. Emergency power support is provided, excessive reduction of system frequency or voltage collapse is prevented, and the anti-interference capability and reliability of a power grid are enhanced.

Description

Technical Field

[0001] The present invention relates to the field of electric power, and more specifically, to a method and system for energy storage to participate in section control. Background Art

[0002] With the continuous deepening of the power system reform, the power market has gradually formed and improved. In the power market environment, grid operation needs to pay more attention to economic benefits and the optimal allocation of resources. Energy storage participating in section control can be used as a flexible resource and play a role in different market scenarios, such as participating in peak shaving and valley filling in the electricity market, frequency modulation and voltage regulation in the ancillary service market, etc. By optimizing the utilization efficiency of transmission sections, the operation cost of the grid can be reduced, and the overall economic benefits of the grid can be improved.

[0003] The traditional way for energy storage to participate in the active power control of the power grid is relatively single, mainly participating in the peak shaving control of the power grid. Limited by scale and capacity, it participates less in section control. In recent years, the stability of the power system has become increasingly important for ensuring power supply quality. When there are situations such as power imbalance, voltage fluctuation or frequency abnormality in the power grid, it may trigger system oscillation or even power outage accidents. The energy storage system can adjust the power of the power grid in real time through rapid charge and discharge, maintain the voltage and frequency stability of the power grid, improve the stability of the transmission section, and enhance the ability of the power grid to resist faults and disturbances.

[0004] In view of the above problems, there is an urgent need for a method and system for energy storage to participate in section control. Summary of the Invention

[0005] To solve the deficiencies in the prior art, the present invention provides a method and system for energy storage to participate in section control, which detects the section load rate and distributes discharge instructions to the energy storage station according to the distribution strategy.

[0006] The present invention adopts the following technical solutions.

[0007] In a first aspect of the present invention, it relates to a method for energy storage to participate in section control. The method includes the following steps: Mount the energy storage station under the section and detect the section load rate; When the energy storage section load rate is higher than the first load rate threshold, prohibit the energy storage station from discharging and calculate the energy storage section adjustment amount, and distribute discharge instructions to the energy storage station according to the distribution strategy until the section adjustment requirement is met; When the energy storage section load rate is between the first load rate threshold and the second load rate threshold, the discharging energy storage station maintains the current active power unchanged; When the energy storage section load rate is lower than the second load rate threshold, the energy storage power station performs charge and discharge after verifying the energy storage instruction according to the self-use instruction value, planned value, and peak shaving target sent.

[0008] When the energy storage section load rate is higher than the first load rate threshold, prohibiting the energy storage station from discharging and calculating the energy storage section adjustment amount includes: The energy storage section adjustment amount = section limit * first load rate threshold - section active power.

[0009] Allocate discharge commands to energy storage stations according to the allocation strategy until the section regulation demand is met, including: allocating discharge commands to the energy storage power stations that are discharging according to the allocation strategy, and gradually reducing the command value by a step size until it is reduced to 0.0 MW or the section regulation demand is met.

[0010] The allocation strategies are discharge power ratio allocation and electricity percentage allocation.

[0011] The discharge power ratio allocation is as follows: when the energy storage section peak shaving target is discharging, the energy storage stations participating in section peak shaving control under the section are sorted and allocated according to the electricity percentage. The stations with a larger electricity percentage are allocated first, and at least one discharge step size is allocated; when the energy storage section peak shaving target is charging, the energy storage stations participating in section peak shaving control under the section are sorted and allocated according to the electricity percentage. The stations with a larger electricity percentage are allocated first, and at least one charging step size is allocated.

[0012] The electricity percentage allocation is as follows: when the energy storage section peak shaving target is discharging, the energy storage stations participating in section peak shaving control under the section are allocated the regulation target according to the maximum discharge power as a ratio, and at least one discharge step size is allocated; when the energy storage section peak shaving target is charging, the energy storage stations participating in section peak shaving control under the section are allocated the regulation target according to the maximum charging power as a ratio, and at least one charging step size is allocated.

[0013] The energy storage command verification includes step size verification, allowable charge and discharge verification, electricity verification, maximum charge and discharge power verification, and grid verification.

[0014] In the second aspect of the present invention, there is provided an energy storage participation section control system, and the system is implemented by using an energy storage participation section control method in the first aspect of the present invention; the system includes a detection module, an allocation module, a maintenance module, and an adjustment module; the detection module is used to mount the energy storage station under the section and detect the section load rate; the allocation module is used to prohibit the energy storage station from discharging and calculate the energy storage section regulation amount when the energy storage section load rate is higher than the first load rate threshold, and allocate discharge commands to the energy storage station according to the allocation strategy until the section regulation demand is met; the maintenance module is used to keep the current active power of the discharging energy storage station unchanged when the energy storage section load rate is between the first load rate threshold and the second load rate threshold; the adjustment module is used to perform charge and discharge on the energy storage power station after energy storage command verification according to the self-use command value, planned value, and peak shaving target sent when the energy storage section load rate is lower than the second load rate threshold.

[0015] In the third aspect of the present invention, there is provided a terminal, including a processor and a storage medium; the storage medium is used to store instructions; the processor is used to operate according to the instructions to execute the steps of the method described in the first aspect of the present invention.

[0016] In the fourth aspect of the present invention, it relates to a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the steps of the method described in the first aspect of the present invention are implemented.

[0017] The beneficial effects of the present invention are as follows. Compared with the prior art, in a method and system for energy storage to participate in section control in the present invention, the section load rate is detected, and a discharge instruction is allocated to the energy storage station according to the allocation strategy. By configuring energy storage near the transmission section, the present invention releases electric energy to the power grid during peak load to relieve the transmission pressure of the section; and absorbs electric energy during low load to avoid too low section power, thereby making full use of the transmission capacity of the section and improving its transmission ability. At the same time, when a power grid failure or power deficit occurs, the energy storage can quickly be put into operation to provide emergency power support, prevent excessive decline of the system frequency or voltage collapse, and enhance the anti-interference ability and reliability of the power grid.

[0018] The beneficial effects of the present invention also include:

[0019] 1. Improve the operation efficiency of the power grid. Optimize the power flow distribution: The energy storage system can flexibly absorb or release electric energy according to the real-time operation state of the power grid, adjust the power distribution on the transmission line, make the power flow more reasonable, reduce line losses, and improve the overall operation efficiency of the power grid. Improve the section transmission ability: By configuring energy storage near the transmission section, the present invention releases electric energy to the power grid during peak load to relieve the transmission pressure of the section; and absorbs electric energy during low load to avoid too low section power, thereby making full use of the transmission capacity of the section and improving its transmission ability.

[0020] 2. Enhance the stability of the power grid. Suppress power fluctuations: For the power fluctuations brought by new energy power generation, the energy storage can quickly respond and perform charge and discharge operations, convert the unstable power output into relatively stable power, reduce the impact on the power grid, and maintain the stability of the power grid frequency and voltage. Improve system reliability: When a power grid failure or power deficit occurs, the energy storage can quickly be put into operation to provide emergency power support, prevent excessive decline of the system frequency or voltage collapse, and enhance the anti-interference ability and reliability of the power grid.

[0021] 3. Promote the consumption of new energy. Solve the problem of curtailment of wind and solar power: When new energy power generation is excessive, the energy storage system stores the excess electric energy, avoids the curtailment of wind and solar power phenomena caused by insufficient grid acceptance capacity, improves the utilization rate of new energy, and promotes the large-scale development of new energy. Realize time and space translation: The energy storage can translate new energy in time and space to better match its power generation with the load demand. For example, store electric energy during the day when photovoltaic power generation is excessive and release it during the peak load at night to meet the electricity consumption needs of users.

[0022] 4. Improve the flexibility of the power grid. Quick response regulation: Energy storage systems have a fast charge and discharge response speed and can adjust power according to the control instructions of the power grid within a short time. They are more flexible than traditional power generation equipment and regulation means and can adapt to the rapidly changing operating conditions of the power grid. Flexible configuration and application: Energy storage can be flexibly configured at different locations according to the needs of the power grid, such as substations, along transmission lines, or on the user side, etc., to achieve effective control of different transmission sections. And its operating mode and control strategy can be adjusted according to actual needs to meet the diverse operating requirements of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic flowchart of a method for energy storage to participate in section control according to the present invention;

[0024] Figure 2 is a schematic diagram of a system for energy storage to participate in section control according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To make the objectives, technical solutions and advantages of the present invention clearer and more accurate, the technical solutions of the present invention will be described in detail below through multiple specific embodiments. The embodiments adopted in the present invention are only used to explain the present invention and do not limit the content of the present invention.

[0026] Figure 1 is a schematic flowchart of a method for energy storage to participate in section control according to the present invention. In the first aspect of the present invention, a method for energy storage to participate in section control is provided, and the method includes the following steps:

[0027] Step 1, mount the energy storage station under the section and detect the section load rate.

[0028] The automatic generation control function module makes the power generation automatically track the load change by controlling the active power of the generating units within the dispatching area, maintains the system frequency at the rated value, and maintains the interchange power of the grid tie lines. Traditional power sources represented by thermal power and hydropower are the main regulation resources of AGC. However, with the progress of energy storage system technology and the reduction of costs, more and more energy storage systems are connected to the grid for operation. Compared with traditional thermal power units, energy storage systems can usually respond quickly to frequency changes and are suitable for participating in the frequency regulation of the power system.

[0029] In one embodiment, a tree-like structure model of the energy storage section is established, and the energy storage controller model is associated with the section model to mount the energy storage station under the section. Based on the energy storage section parameters, the peak shaving target power of each section is set. Select a certain section to enable peak shaving control and input the peak shaving target value. According to the section allocation strategy selected by the user, the peak shaving target value is allocated to the controllable energy storage stations under the section and under the sub-section according to the energy storage charging and discharging step lengths. The present invention is improved on this basis.

[0030] Section load rate = Section active power / Section limit value.

[0031] Step 2: When the energy storage section load rate is higher than the first load rate threshold, prohibit the energy storage station from discharging and calculate the energy storage section regulation amount. Allocate discharge commands to the energy storage station according to the allocation strategy until the section regulation demand is met.

[0032] The first load rate threshold and the second load rate threshold can be manually configured, such as 95% and 90% of the energy storage section limit value.

[0033] Mount the energy storage station under the actual section. When the energy storage section load rate is higher than 95%, prohibit the energy storage station from discharging. The energy storage section regulation amount = Section limit value * 95% - Section active power. The energy storage power stations that are discharging are allocated according to the allocation strategy, and the command value is gradually decreased in steps until it reaches 0.0 MW or the section regulation demand is met. The commands for the charging stations are issued normally.

[0034] The allocation strategies are discharge power ratio allocation and electricity percentage allocation.

[0035] Discharge power ratio allocation: When the energy storage section peak shaving target is discharging, the energy storage stations participating in the section peak shaving control under the section are sorted and allocated according to the electricity percentage. The stations with a larger electricity percentage are allocated preferentially, and at least one discharge step is allocated. When the energy storage section peak shaving target is charging, the energy storage stations participating in the section peak shaving control under the section are sorted and allocated according to the electricity percentage. The stations with a larger electricity percentage are allocated preferentially, and at least one charging step is allocated.

[0036] Electricity percentage allocation: When the energy storage section peak shaving target is discharging, the energy storage stations participating in the section peak shaving control under the section are allocated the regulation target according to the maximum discharge power as a proportion, and at least one discharge step is allocated. When the energy storage section peak shaving target is charging, the energy storage stations participating in the section peak shaving control under the section are allocated the regulation target according to the maximum charging power as a proportion, and at least one charging step is allocated.

[0037] Step 3: When the energy storage section load rate is between the first load rate threshold and the second load rate threshold, the discharging energy storage stations maintain the current active power unchanged.

[0038] When the energy storage section load rate is between 90% and 95%, the discharging energy storage stations maintain the current active power unchanged, and the commands for the charging stations are issued normally.

[0039] Step 4: When the energy storage section load rate is lower than the second load rate threshold, the energy storage power station charges and discharges according to the self-use command value, planned value, and peak shaving target sent up after passing the energy storage command verification.

[0040] When the load rate of the energy storage section is lower than 90%, the energy storage power station charges and discharges after verification such as step size according to the self-use instruction value, planned value, peak shaving target, etc. sent up.

[0041] The energy storage instruction verification is applied in steps 2, 3, and 4.

[0042] The energy storage instruction verification includes step size verification, allowable charge and discharge verification, power quantity verification, maximum charge and discharge power verification, and grid connection verification. Step size verification: The difference between the real-time power of the energy storage station and the instruction shall not exceed a preset step size. Allowable charge and discharge verification: For the stations where the dispatching has set not to allow charging, no charging instructions will be issued; for the stations where the dispatching has set not to allow discharging, no discharging instructions will be issued. Power quantity verification: When the maximum power quantity is reached, no charging instructions will be issued; when the minimum power quantity is reached, no discharging instructions will be issued. Maximum charge and discharge power verification: The energy storage instruction value is not allowed to exceed the maximum charge and discharge power, and if it exceeds, it will be corrected to the maximum charge and discharge power. Grid connection verification: The charging power of the energy storage station built in parallel with the power grid shall not be higher than the power generation power of its new energy station.

[0043] By controlling the section with energy storage participation, the charge and discharge characteristics of the energy storage resources under the section are fully utilized, the section power is prevented from being too low, so as to fully utilize the transmission capacity of the section, improve its transmission ability, prevent the system frequency from dropping excessively or voltage collapse, and enhance the anti-interference ability and reliability of the power grid.

[0044] The present invention also proposes a one-key no-charge-no-discharge function for the energy storage section. When the energy storage section charging is over-limit, a no-charging mark is placed on the corresponding section, and a no-charging mark is placed on the energy storage stations under the section, and the energy storage stations are not allowed to perform charging operations; when the energy storage section discharging is over-limit, a no-discharging mark is placed on the corresponding section, and a no-discharging mark is placed on the energy storage stations under the section, and the energy storage stations are not allowed to perform discharging operations. This mark is verified before the instruction is issued.

[0045] Figure 2 FIG. is a schematic diagram of a control system for energy storage participating in section of the present invention. In the second aspect of the present invention, it relates to a control system for energy storage participating in section; the system is implemented by using the method described in the first aspect of the present invention; the system includes a detection module, a distribution module, a maintenance module, and an adjustment module; the detection module is used to mount the energy storage station under the section and detect the section load rate; the distribution module is used to prohibit the energy storage station from discharging and calculate the section adjustment amount of the energy storage when the load rate of the energy storage section is higher than the first load rate threshold, and distribute discharge instructions to the energy storage station according to the distribution strategy until the section adjustment requirement is met; the maintenance module is used to keep the current active power unchanged for the discharging energy storage stations when the load rate of the energy storage section is between the first load rate threshold and the second load rate threshold; the adjustment module is used to charge and discharge the energy storage power station after energy storage instruction verification according to the self-use instruction value, planned value, and peak shaving target sent up when the load rate of the energy storage section is lower than the second load rate threshold.

[0046] In a third aspect of the present invention, there is provided a terminal, comprising a processor and a storage medium; the storage medium is used for storing instructions; the processor is used for operating according to the instructions to execute the steps of the method described in the first aspect of the present invention.

[0047] In a fourth aspect of the present invention, there is provided a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the method described in the first aspect of the present invention are implemented.

[0048] 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 them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that there are still contents in the technical solutions of the present invention that can be modified or equivalently replaced for the specific implementation manners of the present invention. Any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A method for energy storage to participate in section control, characterized in that, The method includes the following steps: Mount the energy storage station under the section and detect the section load rate; When the energy storage section load rate is higher than the first load rate threshold, prohibit the energy storage station from discharging, calculate the energy storage section regulation amount, and allocate discharge instructions to the energy storage station according to the allocation strategy until the section regulation demand is met; When the energy storage section load rate is between the first load rate threshold and the second load rate threshold, the active power of the discharging energy storage station remains unchanged; When the energy storage section load rate is lower than the second load rate threshold, the energy storage power station performs charge and discharge after the energy storage instruction is verified according to the self-use instruction value, planned value, and peak shaving target sent up.

2. A method for controlling a section by energy storage according to claim 1, wherein: When the energy storage section load rate is higher than the first load rate threshold, prohibiting the energy storage station from discharging and calculating the energy storage section regulation amount includes: The energy storage section regulation amount = section limit value * first load rate threshold - section active power.

3. A method for controlling a section by energy storage according to claim 2, wherein: Allocating discharge instructions to the energy storage station according to the allocation strategy until the section regulation demand is met includes: Allocate discharge instructions to the discharging energy storage power station according to the allocation strategy, and gradually lower the instruction value in steps until it is lowered to 0.0 MW or the section regulation demand is met.

4. A method for controlling a section by energy storage according to claim 3, wherein: The allocation strategy is discharge power ratio allocation and electricity percentage allocation.

5. A method for controlling a section by energy storage according to claim 4, wherein: The discharge power ratio allocation is as follows: When the peak shaving target of the energy storage section is discharging, the energy storage stations participating in the peak shaving control of the section are sorted and allocated according to the electricity percentage. The stations with a larger electricity percentage are allocated first, and at least one discharge step is allocated; When the peak shaving target of the energy storage section is charging, the energy storage stations participating in the peak shaving control of the section are sorted and allocated according to the electricity percentage. The stations with a larger electricity percentage are allocated first, and at least one charging step is allocated.

6. A method for controlling a section by energy storage according to claim 4, wherein: The electricity percentage allocation is as follows: When the peak shaving target of the energy storage section is discharging, the energy storage stations participating in the peak shaving control of the section are allocated the regulation target according to the maximum discharge power as a ratio, and at least one discharge step is allocated; When the peak shaving target of the energy storage section is charging, the energy storage stations participating in the peak shaving control of the section are allocated the regulation target according to the maximum charging power as a ratio, and at least one charging step is allocated.

7. A method for controlling a section by energy storage according to claim 5 or 6, wherein: The energy storage instruction verification includes step verification, allowable charge and discharge verification, electricity verification, maximum charge and discharge power verification, and network verification.

8. An energy storage section control system, wherein: The system is implemented by using the method for controlling a section by energy storage according to any one of claims 1-7; The system includes a detection module, an allocation module, a maintenance module, and an adjustment module; The detection module is used to mount the energy storage station under the section and detect the section load rate; The distribution module is configured to prohibit the energy storage station from discharging and calculate the adjustment amount of the energy storage section when the load rate of the energy storage section is higher than the first load rate threshold, and distribute discharge commands to the energy storage station according to the distribution strategy until the section adjustment demand is met; The maintenance module is configured to keep the current active power of the discharging energy storage station unchanged when the load rate of the energy storage section is between the first load rate threshold and the second load rate threshold; The adjustment module is configured to charge and discharge the energy storage power station after energy storage instruction verification according to the self-use instruction value, planned value, and peak shaving target sent when the load rate of the energy storage section is lower than the second load rate threshold.

9. A terminal, comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the steps of the method according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, the steps of the method according to any one of claims 1-7 are implemented.

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