Power delivery channel near area energy storage control strategy optimization method and system

Abstract

The invention discloses a power delivery channel near-region energy storage control strategy optimization method and system, and the method comprises the steps: determining a key fault restricting the stability of a power angle according to an operation mode of a power system; determining the grouping position of the energy storage power station according to the position of the energy storage power station; and selecting a control strategy for energy storage fault ride-through according to the grouping position of the energy storage power station and the charging and discharging state of the energy storage power station. And control strategies of different control parameters are adopted for different energy storage operation states and energy storage position scenes, so that the power angle stability is effectively improved.

Description

Technical Field

[0001] The present invention relates to power system control, and in particular to a method and system for optimizing a control strategy for near-area energy storage in a power transmission channel. Background Art

[0002] The huge power shock generated during the low-breakthrough of new energy can cause the system power angle to swing greatly or even cause power angle instability, which has become one of the key factors restricting the safe and stable operation of high-proportion new energy transmission channels.

[0003] In recent years, with the extensive promotion and application of electrochemical energy storage, it has provided the system with high-quality control resources and played an important role in the system power balance and system stability. In the vicinity of the channel where a high proportion of new energy is transmitted, once a fault occurs, it may cause the power angle of the unit near the transmission channel to become unstable. The huge power impact caused by the low penetration of new energy caused by the voltage drop under the fault will further aggravate the complexity of the power angle stability problem and even deteriorate the power angle stability. Summary of the invention

[0004] Purpose of the invention: In view of the above shortcomings, the present invention provides a method and system for optimizing the control strategy of energy storage in the vicinity of power transmission channels. This method can make up for the lack of optimization methods for energy storage fault ride-through parameters in scenarios with power angle stability problems, and provide support for the optimization design of energy storage parameters in the vicinity of large-scale energy transmission channels.

[0005] Technical solution: To solve the above problems, the present invention adopts an energy storage control strategy optimization method, which includes the following steps:

[0006] Step 1: According to the operation mode of the power system, determine the key faults that restrict the stability of the power angle and the corresponding transmission channels;

[0007] Step 2: According to the location of the energy storage power station, determine the cluster location of the energy storage power station;

[0008] Step 3: Select the control strategy for energy storage fault ride-through based on the cluster location of the energy storage power station and its charging and discharging status.

[0009] Furthermore, the key faults that restrict the power angle stability are specifically determined as follows:

[0010] According to the operation mode of the power system, the expected fault set is determined, and the stability of the expected fault set is simulated and calculated using the FASTEST software. According to the simulation results, the fault with the smallest power angle stability margin is selected as the key fault, and the corresponding unstable section under the key fault is the key channel.

[0011] Furthermore, the control strategy for energy storage fault ride-through in step 3 includes:

[0012] When the energy storage power station is in the critical group and the energy storage power station is in the discharging state, the control strategy is:

[0013] The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Hm :

[0014] During the low-voltage run-through period, the energy storage power station adopts a reactive power priority control mode;

[0015] The energy storage power station recovery strategy during low-voltage breakout is based on the slope recovery, and the recovery rate is K M ;

[0016] When the energy storage power station is in the critical group and the energy storage power station is in the charging state, the control strategy is:

[0017] The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Lm :

[0018] During the low-voltage period, the energy storage power station adopts a control method based on the percentage of active power;

[0019] The energy storage power station's recovery strategy during low-voltage breakout is implemented in accordance with the strategy of immediate recovery during low-voltage breakout;

[0020] When the energy storage power station is in the remaining group and the energy storage power station is in the discharging state, the control strategy is:

[0021] The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Lm :

[0022] During the low-voltage run-through period, the energy storage power station adopts a reactive power priority control mode;

[0023] The energy storage power station's recovery strategy during low-voltage breakout is implemented in accordance with the strategy of immediate recovery during low-voltage breakout;

[0024] When the energy storage station is in the remaining group and is in the charging state, the control strategy is:

[0025] The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Hm :

[0026] During the low-voltage run-through period, the energy storage power station adopts fixed active power control, and the power control constant is set to 0;

[0027] The energy storage power station recovery strategy during low-voltage breakout is based on the slope recovery, and the recovery rate is K M ;

[0028] Among them, U Hm U is the upper limit of the voltage threshold for the energy storage station to enter the low voltage ride-through state. Lm It is the lower limit of the voltage threshold for the energy storage power station to enter the low voltage ride-through state.

[0029] The present invention also adopts a method and system for optimizing the control strategy of near-area energy storage in a power transmission channel, including:

[0030] The key fault determination module is used to determine the key faults that restrict the stability of the power angle and the corresponding transmission channels according to the operation mode of the power system;

[0031] A grouping module determines the grouping location of the energy storage power station according to the location of the energy storage power station;

[0032] The control strategy determination module is used to select the control strategy for energy storage fault ride-through according to the cluster location of the energy storage power station and its charging and discharging status.

[0033] The present invention also adopts a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0034] The present invention also adopts a computer-readable storage medium on which a computer program is stored, and the computer program implements the steps of the above method when executed by a processor.

[0035] Beneficial effect: Compared with the prior art, the significant advantage of the present invention is that it addresses the problem of power angle instability in the vicinity of the transmission channel of a large energy base under a short-circuit fault, takes into account the different requirements for energy storage support performance under different operating states and location scenarios of energy storage, and proposes an energy storage low-penetration parameter optimization method, which provides a reference for the optimization of energy storage grid-related parameters to address the problem of power angle stability and improves the power angle stability. DETAILED DESCRIPTION

[0036] Example 1

[0037] The impact of energy storage near the transmission channel on the power angle stability is closely related to its charging and discharging state. Different operating conditions and control parameters will have different impacts on the power angle stability. How to optimize the energy storage control strategy and control parameters in combination with the different charging and discharging states of energy storage and its location so that it can better support the stable operation of the system is a very necessary research topic. In order to maximize the supporting role of energy storage for the power angle stability of large-scale energy transmission bases, it is necessary to optimize the low-penetration control parameters of energy storage near the transmission channel.

[0038] In this embodiment, a method for optimizing the control strategy of energy storage near the power transmission channel is provided to determine the key faults that restrict the stability of the power angle, determine the grouping location of the energy storage, and optimize the energy storage fault ride-through control strategy according to the location and charging and discharging status of the energy storage. The method includes the following steps:

[0039] Step 1: According to the determined operation mode, determine the expected fault set, and use FASTEST power system safety and stability quantitative analysis and optimization decision-making software to simulate and calculate the determined expected fault set; according to the simulation calculation results, screen out the fault with the smallest power angle stability margin, which is recorded as fault i. This fault is the key fault, and the corresponding unstable section under the key fault is the key channel.

[0040] Step 2: According to the location of the energy storage power station, determine the clustering location of the energy storage power station. If the energy storage is at the sending end of the key channel, it is classified as the critical group, otherwise it is classified as the remaining group.

[0041] Step 3: Select the control strategy for energy storage fault ride-through based on the cluster location of the energy storage power station and its charging and discharging status. Specifically,

[0042] (1) Energy storage is in the critical group

[0043] ① If the energy storage is in the discharge state:

[0044] The voltage threshold for energy storage to enter the low voltage ride-through state is set to U Hm :

[0045] During the low-breakdown period of energy storage, the reactive power priority control mode is adopted;

[0046] The energy storage recovery strategy during the low-breakout period is based on the slope recovery, and the recovery rate is K M .

[0047] ② If the energy storage is in charging state:

[0048] The voltage threshold for energy storage to enter the low voltage ride-through state is set to U Lm :

[0049] During the period of low energy storage penetration, the control method based on the percentage of active power is adopted;

[0050] The energy storage recovery strategy during low-voltage breakthrough is implemented in accordance with the strategy of immediate recovery after low-voltage breakthrough.

[0051] (2) Energy storage is in the remaining group

[0052] ① If the energy storage is in charging state:

[0053] The voltage threshold for energy storage to enter the low voltage ride-through state is set to U Hm :

[0054] During the low penetration period of energy storage, fixed active power control is adopted, and the power control constant is set to 0;

[0055] The energy storage recovery strategy during low-voltage breakthrough is based on the slope recovery, and the recovery rate is KM.

[0056] ② If the energy storage is in the discharge state:

[0057] The voltage threshold for energy storage to enter the low voltage ride-through state is set to U Lm :

[0058] During the low-breakdown period of energy storage, the reactive power priority control mode is adopted;

[0059] The energy storage recovery strategy during low-voltage breakthrough is implemented in accordance with the strategy of immediate recovery after low-voltage breakthrough.

[0060] U Hm , U Lm They are the upper and lower limits of the voltage threshold for the energy storage to enter the low voltage ride-through state. Hm According to the "GB / T36547-2018 Technical Regulations for the Access of Electrochemical Energy Storage Systems to the Grid" and "GB / T 34120-2017 Technical Specifications for Energy Storage Converters of Electrochemical Energy Storage Systems", the general value is around 0.85pu~0.9pu; U Lm Determined based on equipment safety constraints and through research with equipment manufacturers.

[0061] According to GB / T 34120-2017 Technical Specifications for Energy Storage Converters of Electrochemical Energy Storage Systems, “For energy storage converters that are not disconnected during a power system fault, their active power should be able to recover quickly after the fault is cleared, and recover to the value before the fault at a power change rate of at least 30% of the rated power / second from the moment the fault is cleared”, K M Take 30%.

[0062] Example 2

[0063] In this embodiment, a power transmission channel near-area energy storage control strategy optimization system includes:

[0064] The key fault determination module is used to determine the key faults that restrict the stability of the power angle and the corresponding transmission channels according to the operation mode of the power system;

[0065] A grouping module determines the grouping location of the energy storage power station according to the location of the energy storage power station;

[0066] The control strategy determination module is used to select the control strategy for energy storage fault ride-through according to the cluster location of the energy storage power station and its charging and discharging status.

[0067] Example 3

[0068] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0069] The present invention is described with reference to the flowchart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the process and / or box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one process or multiple processes in the flowchart and / or one box or multiple boxes in the block diagram.

[0070] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0071] These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0072] The embodiments of the present invention are described above, but the present invention is not limited to the above-mentioned specific implementation modes. The above-mentioned specific implementation modes are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection of the present invention.

Claims

1. A method and system for optimizing the control strategy of near-area energy storage in a power transmission channel, characterized in that: The following steps are involved: Step 1: According to the operation mode of the power system, determine the key faults that restrict the stability of the power angle and the corresponding transmission channels; Step 2: According to the location of the energy storage power station, determine the cluster location of the energy storage power station; Step 3: Select the control strategy for energy storage fault ride-through based on the cluster location of the energy storage power station and its charging and discharging status.

2. The energy storage control strategy optimization method according to claim 1, characterized in that: The key faults that restrict the power angle stability are specifically: According to the operation mode of the power system, the expected fault set is determined, and the stability of the expected fault set is simulated and calculated using the FASTEST software. According to the simulation results, the fault with the smallest power angle stability margin is selected as the key fault, and the corresponding unstable section under the key fault is the key channel.

3. The energy storage control strategy optimization method according to claim 2 is characterized in that: According to the location of the energy storage, the location of the energy storage power station is determined. If the energy storage is at the sending end of the key channel, it is classified as the critical group, otherwise it is classified as the remaining group.

4. The energy storage control strategy optimization method according to claim 3 is characterized in that: The control strategy of energy storage fault ride-through in step 3 includes: When the energy storage power station is in the critical group and the energy storage power station is in the discharging state, the control strategy is: The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Hm : During the low-voltage run-through period, the energy storage power station adopts a reactive power priority control mode; The energy storage power station recovery strategy during low-voltage breakout is based on the slope recovery, and the recovery rate is K M ; When the energy storage power station is in the critical group and the energy storage power station is in the charging state, the control strategy is: The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Lm : During the low-voltage period, the energy storage power station adopts a control method based on the percentage of active power; The energy storage power station's recovery strategy during low-voltage breakout is implemented in accordance with the strategy of immediate recovery during low-voltage breakout; When the energy storage power station is in the remaining group and the energy storage power station is in the discharging state, the control strategy is: The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Lm : During the low-voltage run-through period, the energy storage power station adopts a reactive power priority control mode; The energy storage power station's recovery strategy during low-voltage breakout is implemented in accordance with the strategy of immediate recovery during low-voltage breakout; When the energy storage station is in the remaining group and is in the charging state, the control strategy is: The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Hm : During the low-voltage run-through period, the energy storage power station adopts fixed active power control, and the power control constant is set to 0; The energy storage power station recovery strategy during low-voltage breakout is based on the slope recovery, and the recovery rate is K M ; Among them, U Hm U is the upper limit of the voltage threshold for the energy storage station to enter the low voltage ride-through state. Lm It is the lower limit of the voltage threshold for the energy storage power station to enter the low voltage ride-through state.

5. A method and system for optimizing the control strategy of near-area energy storage in a power transmission channel, characterized in that: include: The key fault determination module is used to determine the key faults that restrict the stability of the power angle and the corresponding transmission channels according to the operation mode of the power system; A grouping module determines the grouping location of the energy storage power station according to the location of the energy storage power station; The control strategy determination module is used to select the control strategy for energy storage fault ride-through according to the cluster location of the energy storage power station and its charging and discharging status.

6. The energy storage control strategy optimization system according to claim 5, characterized in that: The key faults that restrict the power angle stability are specifically: According to the operation mode of the power system, the expected fault set is determined, and the stability of the expected fault set is simulated and calculated using the FASTEST software. According to the simulation results, the fault with the smallest power angle stability margin is selected as the key fault, and the corresponding unstable section under the key fault is the key channel.

7. The energy storage control strategy optimization system according to claim 5, characterized in that: According to the location of the energy storage power station, the location of the energy storage power station is determined. If the energy storage is at the sending end of the key channel, it is classified as the critical group, otherwise it is classified as the remaining group.

8. The energy storage control strategy optimization system according to claim 6, characterized in that: The control strategy of energy storage fault ride-through in step 3 includes: When the energy storage power station is in the critical group and the energy storage power station is in the discharging state, the control strategy is: The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Hm : During the low-voltage run-through period, the energy storage power station adopts a reactive power priority control mode; The energy storage power station recovery strategy during low-voltage breakout is based on the slope recovery, and the recovery rate is K M ; When the energy storage power station is in the critical group and the energy storage power station is in the charging state, the control strategy is: The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Lm : During the low-voltage period, the energy storage power station adopts a control method based on the percentage of active power; The energy storage power station's recovery strategy during low-voltage breakout is implemented in accordance with the strategy of immediate recovery during low-voltage breakout; When the energy storage power station is in the remaining group and the energy storage power station is in the discharging state, the control strategy is: The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Lm : During the low-voltage run-through period, the energy storage power station adopts a reactive power priority control mode; The energy storage power station's recovery strategy during low-voltage breakout is implemented in accordance with the strategy of immediate recovery during low-voltage breakout; When the energy storage station is in the remaining group and is in the charging state, the control strategy is: The voltage threshold for the energy storage station to enter the low voltage ride-through state is set to U Hm : During the low-voltage run-through period, the energy storage power station adopts fixed active power control, and the power control constant is set to 0; The energy storage power station recovery strategy during low-voltage breakout is based on the slope recovery, and the recovery rate is K M ; Among them, U Hm U is the upper limit of the voltage threshold for the energy storage station to enter the low voltage ride-through state. Lm It is the lower limit of the voltage threshold for the energy storage power station to enter the low voltage ride-through state.

9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.