A method for suppressing power fluctuation of an energy storage power station based on coordinated control, and a medium

Abstract

The application provides a kind of energy storage power station power fluctuation suppression method based on coordinated control, medium, it is related to energy storage power station power adjustment technical field, comprising: based on energy controller generation power distribution strategy, and based on active support device generation support control strategy, action mark and reset mark;With action mark and reset mark to trace back support control time interval / power distribution time interval;Coordinated controller executes support control strategy in support control time interval, and executes power distribution strategy in power distribution time interval.This technical solution integrates power distribution strategy and support control strategy into coordinated controller, then judges whether support control strategy is executed based on action mark and reset mark, and then selectively executes support control strategy or power distribution strategy in the corresponding time interval to control power conversion system, to avoid the problem that strategy conflict causes energy storage power station power fluctuation.

Description

Technical Field

[0001] This invention relates to the field of power regulation technology for energy storage power stations, specifically to a method and medium for suppressing power fluctuations in energy storage power stations based on coordinated control. Background Technology

[0002] In existing power adjustment schemes for energy storage power stations, the energy management system and the coordination controller control the power conversion system independently. That is, the energy management system issues power allocation strategies from the perspective of economic dispatch to control the power conversion system, while the active support device issues and executes support control strategies from the perspective of stability control. The coordination controller analyzes and processes the support control strategies to control the power conversion system. However, there may be contradictions and conflicts between the power allocation strategy and the support control strategy, and the two take turns controlling the power conversion system, which can easily lead to repeated power jumps in the energy storage power station, thus causing power fluctuation problems. Therefore, there is an urgent need for a technical solution to suppress power fluctuations in energy storage power stations to solve the above problems.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a method and medium for suppressing power fluctuations in energy storage power stations based on coordinated control, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for suppressing power fluctuations in an energy storage power station based on coordinated control includes the following steps: S1, based on the energy management system, issues a power allocation strategy, and based on the coordination controller, receives the support control strategy, action flag and reset flag from the active support device. If a new support control strategy is added during the active support device's execution of the action, the original support control strategy is modified by taking the largest value in the same direction based on the new support control strategy, and then the action is re-executed based on the modified support control strategy. S2, determine the latest action flag received by the coordination controller as the target action flag, and determine whether the coordination controller has received a return flag belonging to the same action as the target action flag up to the current time. If the determination result is no, proceed to step S3; otherwise, proceed to step S4. S3, starting from the current moment, trace back to the moment when the coordination controller first received the reset flag to form a support control time interval in which the coordination controller does not receive power allocation strategies. Within the support control time interval, the coordination controller outputs the corresponding global support control command for each support control strategy. S4, starting from the current moment, trace back to the moment when the coordination controller first received the action flag, and use it as the power allocation time interval for the coordination controller to receive the power allocation strategy. Within the power allocation time interval, instruct the coordination controller to output the corresponding global power allocation command for each power allocation strategy.

[0006] Furthermore, the power allocation strategy generation logic is as follows: The on-site platform of the energy storage power station receives and analyzes safety event data from automatic safety devices, real-time power generation / power control information from automatic generation control substations, and voltage / reactive power control related information from automatic voltage control substations to generate adjustment constraint instructions, which include global active power targets, global reactive power targets, and SOC constraint intervals. Based on the energy management system receiving and analyzing the adjustment constraint instructions, a power allocation strategy is generated and output. The power allocation strategy includes the target active power and target reactive power of each power conversion system within the energy storage power station.

[0007] Furthermore, the energy management system adopts the instruction overlay method to receive adjustment constraint instructions, so as to realize the update and replacement of the current adjustment constraint instructions. After each round of update and replacement of the current adjustment constraint instructions is completed, the energy management system immediately outputs a power allocation strategy based on the current adjustment constraint instructions. Then, according to a fixed strategy sampling frequency, a power allocation strategy is also output based on the current adjustment constraint instructions at each subsequent strategy sampling point until the energy management system receives the next adjustment constraint instruction.

[0008] Furthermore, the generation logic of the support control strategy, action flag, and reset flag is as follows: the active support device receives and analyzes the power allocation strategy from the energy management system, the real-time power generation / power control information from the automatic generation control substation, and the real-time voltage / current signal from the common coupling point, generates the support control strategy and executes the action accordingly, and the active support device synchronously transmits the support control strategy and the action flag at the start of the action to the coordination controller, and transmits the reset flag to the coordination controller at the end of the action. The support control strategy includes the effective time window of the strategy, the active power target adjustment amount and the reactive power target adjustment amount of each power conversion system in the energy storage power station, and the target adjustment amount is positive to indicate an increase and negative to indicate a decrease.

[0009] Furthermore, the support control strategy used by the active support device when performing actions is defined as the baseline support control strategy, i.e., the original support control strategy. If the active support device generates a new support control strategy during the execution of actions based on the baseline support control strategy, i.e., a new support control strategy is added, this newly generated support control strategy is used as the reference support control strategy. The target adjustment amount in the baseline support control strategy is corrected by taking the largest value in the same direction based on the reference support control strategy. The remaining time interval of the active support device's actions under the baseline support control strategy is extracted, and combined with the corrected target adjustment amount, a corrected support control strategy is constructed. The active support device re-executes the actions based on the corrected support control strategy, and sends the action flag and the corrected support control strategy to the coordination controller when re-executing the actions. At the end of the action execution, a reset flag is sent to the coordination controller.

[0010] Furthermore, for the remaining time interval of the action execution, its start time is the start time of the effective time window of the reference support control strategy, and its end time is the end time of the effective time window of the benchmark support control strategy.

[0011] Furthermore, the target adjustment amount includes active power target adjustment amount and reactive power target adjustment amount. The logic for correcting the active power target adjustment amount is as follows: For any power conversion system, the active power target adjustment amount of the power conversion system is extracted from the benchmark support control strategy as the active power benchmark target adjustment amount of the power conversion system, and the active power target adjustment amount of the power conversion system is extracted from the reference support control strategy as the active power reference target adjustment amount of the power conversion system. If both the active power benchmark target adjustment amount and the active power reference target adjustment amount of the power conversion system are positive or negative, the value with the largest absolute value is selected as the corrected active power target adjustment amount of the power conversion system. Otherwise, no correction is performed, that is, the active power target adjustment amount of the power conversion system in the benchmark support control strategy is directly taken as the corrected active power target adjustment amount of the power conversion system. Similarly, the corrected reactive power target adjustment amount of each power conversion system is calculated and obtained.

[0012] Furthermore, the logic of the coordination controller outputting the corresponding global support control command for each support control strategy is as follows: within the support control time interval, the coordination controller receives the support control strategy based on the strategy coverage method to realize the update and replacement of the current support control strategy. Each time the update and replacement of the current support control strategy is completed, the coordination controller outputs a global support control command to the energy storage power station based on the updated and replaced current support control strategy. The global support control command includes the final target value of active power and the final target value of reactive power of each power conversion system of the energy storage power station. The coordination controller releases the rate constraint when outputting the global support control command based on the support control strategy.

[0013] Furthermore, the logic of the coordination controller outputting the corresponding global power allocation command for each power allocation strategy is as follows: within the power allocation time interval, the coordination controller receives the power allocation strategy based on the strategy coverage method to realize the update and replacement of the current power allocation strategy. When the update and replacement of the current power allocation strategy is completed, the coordination controller outputs a global power allocation command that meets the rate constraint and is in step control to the energy storage power station based on the updated and replaced current power allocation strategy. The global power allocation command includes the final target value of active power of each power conversion system of the energy storage power station, the single adjustment step size of active power, the adjustment interval of active power and the number of active power adjustment rounds, as well as the final target value of reactive power of each power conversion system of the energy storage power station, the single adjustment step size of reactive power, the adjustment interval of reactive power and the number of reactive power adjustment rounds. The rate constraint is as follows: 1) In the global power allocation command, the active power adjustment interval and reactive power adjustment interval of each power conversion system shall not be less than the preset adjustment interval threshold. 2) In the global power allocation command, the single adjustment step size of the active power of each power conversion system is no greater than the product of its rated active power and the scaling factor, and the single adjustment step size of the reactive power of each power conversion system is no greater than the product of its rated reactive power and the scaling factor. The scaling factor is a positive value less than 1.

[0014] A medium storing a computer program, which, when executed by a processor, implements the aforementioned method for suppressing power fluctuations in an energy storage power station based on coordinated control.

[0015] Compared with the prior art, the beneficial effects of the present invention are: The present invention relates to a method and medium for suppressing power fluctuations in energy storage power stations based on coordinated control. This method integrates the power allocation strategy issued by the energy management system and the support control strategy issued by the active support device into a unified coordinated controller. The coordinated controller then determines whether the support control strategy has been completed based on action and reset flags. When the support control strategy has not been completed, the coordinated controller only executes the support control strategy to control the power conversion system. After the support control strategy has been completed, the coordinated controller only executes the power allocation strategy to control the power conversion system, thus avoiding power fluctuations in the energy storage power station caused by strategy conflicts. Furthermore, during the execution of actions by the active support device, based on the principle of taking the larger value in the same direction, a new support control strategy is introduced to modify the original support control strategy, avoiding logical conflicts and confusion when the active support controller issues and executes the support control strategy, further improving the suppression effect on power fluctuations in the energy storage power station. Attached Figure Description

[0016] Figure 1 This is a schematic flowchart of the overall method of the present invention; Figure 2 This is a schematic diagram of the control architecture of an energy storage power station in the existing scheme; Figure 3 This is a schematic diagram of the control architecture of the energy storage power station in this technical solution. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0018] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly. Example

[0019] Please see Figures 1-3 This invention provides a method for suppressing power fluctuations in energy storage power stations based on coordinated control, comprising: S1, based on the energy management system, issues a power allocation strategy, and based on the coordination controller, receives the support control strategy, action flag and reset flag from the active support device. If a new support control strategy is added during the active support device's execution of the action, the original support control strategy is modified by taking the largest value in the same direction based on the new support control strategy, and then the action is re-executed based on the modified support control strategy. The power allocation strategy generation logic is as follows: The on-site platform of the energy storage power station receives and analyzes safety event data from automatic safety devices, real-time power generation / power control information from automatic generation control substations, and voltage / reactive power control information from automatic voltage control substations to generate adjustment constraint instructions, which include global active power targets, global reactive power targets, SOC constraint intervals, and instruction effective time windows. Based on the energy management system receiving and analyzing the adjustment constraint instructions, a power allocation strategy is generated and output. The power allocation strategy includes the target active power and target reactive power of each power conversion system within the energy storage power station. As one implementation method, security incident data includes event ID, trigger source, event level, etc. The event ID assigns a unique number to the security incident for easy tracing and playback; the trigger source indicates the area or device that triggered the security incident; the event level is used to measure the severity of the security incident, and the event level can be divided into warning, serious and dangerous in ascending order of severity. As one implementation method, real-time power generation / power control information includes real-time active power, real-time frequency, target active power, target frequency, etc. As one implementation method, voltage / reactive power control related information includes real-time voltage, real-time reactive power, target voltage, target reactive power, etc. It should be noted that the communication relationship between the on-site platform and the safety automatic device, the automatic generation control substation and the automatic voltage control substation to receive and analyze information such as safety event data, real-time generation / power control information and voltage / reactive power control information, and then output adjustment constraint commands is common knowledge in the field of energy storage power station power regulation, and is widely used in the existing field of energy storage power station power regulation, so it will not be elaborated here. The general logic of generating a power allocation strategy based on adjustment constraint instructions is as follows: using the target active power and target reactive power of each power conversion system as optimization variables, the following constraints are set: 1) The relative error between the cumulative target active power of each power conversion coefficient and the global active power target is less than a first preset threshold, which is generally set below 5% to ensure that the cumulative target active power is close to the global active power target; 2) The relative error between the cumulative target reactive power of each power conversion system and the global reactive power target is less than a second preset threshold, which is generally set below 5% to ensure that the cumulative target reactive power is close to the global reactive power target; 3) The S of each power conversion system The OC values ​​are all within their SOC constraint range. The first optimization objective is to minimize the sum of squares of the difference between the target active power and the real-time active power of each power conversion system, and the second optimization objective is to minimize the sum of squares of the difference between the target reactive power and the real-time reactive power of each power conversion system. This ensures that a small adjustment amount is applied to each power conversion system. The optimal solution for the target active power and the target reactive power of each power conversion system is obtained by using a suitable solver (such as quadratic programming, linear programming, robust optimization, etc., depending on the system model and performance requirements). The optimal solution is used as the power allocation strategy. This is common knowledge in the field of energy storage power station power regulation and is widely used in the existing field of energy storage power station power regulation. It will not be elaborated here. Furthermore, a communication connection is established between the energy management system and the energy storage terminal of the energy storage power station, so that the energy management system can read the maximum discharge power and the status information of other stabilization and control devices from the energy storage terminal. This allows the energy management system to obtain as much comprehensive and multi-dimensional information about the energy storage power station as possible, so as to ensure that the energy management system takes into account all aspects when making subsequent output power allocation strategies, and to ensure the accuracy and efficiency of the power allocation strategy. Furthermore, the energy management system adopts the instruction overlay method to receive adjustment constraint instructions in order to update and replace the current adjustment constraint instructions. After each round of updating and replacing the current adjustment constraint instructions, the energy management system immediately outputs a power allocation strategy based on the current adjustment constraint instructions. Then, according to a fixed strategy sampling frequency, a power allocation strategy is also output based on the current adjustment constraint instructions at each subsequent strategy sampling point until the energy management system receives the next adjustment constraint instruction. It should be noted that the logic of receiving adjustment constraint commands using the command overriding method is as follows: When the energy management system receives a new round of adjustment constraint commands, it overwrites the previous round's adjustment constraint commands as the current adjustment constraint commands. This process continues until the energy management system receives the next round of adjustment constraint commands, at which point the next round's commands are used to overwrite the previous round's commands. This achieves the updating and replacement of the current adjustment constraint commands. The application of the command overriding method ensures that there is only one "current adjustment constraint command" within the energy management system. That is, the energy management system only needs to generate a power allocation strategy based on the "current adjustment constraint command," avoiding the simultaneous existence of multiple intertwined adjustment constraint commands, which would lead to the energy management system frequently issuing contradictory power allocation strategies and thus causing power fluctuations in the energy storage power station. It should be noted that the specific value of the strategy sampling frequency is set by the staff according to the actual situation. For example, it can be between once every 3 seconds and once every 5 seconds. Under the same "current adjustment constraint command", the power allocation strategy under each strategy sampling point is generated and output intermittently according to the strategy sampling frequency. Since the real-time active / reactive power data under each strategy sampling point are different, the output power allocation strategy under each strategy sampling point will also change. This realizes the real-time and continuous optimization and update of power allocation, instead of waiting for the command to change before executing once. This ensures the continuity and consistency of power allocation control and improves the real-time response capability of the energy management system. Moreover, after the current adjustment constraint command is updated and replaced, a new round of power allocation strategy output is executed immediately, instead of waiting for the next strategy sampling point to execute a new round of power allocation strategy output, so as to avoid the problem of lag in the generation of power allocation strategy. The generation logic for the support control strategy, action flag, and reset flag is as follows: The active support device receives and analyzes the power allocation strategy from the energy management system, real-time generation / power control information from the automatic generation control substation, and real-time voltage / current signals from the common coupling point. It then generates the support control strategy and executes actions accordingly. The active support device synchronously transmits the support control strategy and the action flag at the start of action execution to the coordination controller, and transmits the reset flag to the coordination controller at the end of action execution. The support control strategy includes the strategy's effective time window, the active power target adjustment amount and reactive power target adjustment amount of each power conversion system within the energy storage power station, and the active power... A positive value for the active power target adjustment indicates an increase in active power, while a negative value indicates a decrease in active power. Similarly, a positive value for the reactive power target adjustment indicates an increase in reactive power, while a negative value indicates a decrease in reactive power. The effective time window of the strategy is used to limit the time interval for the active support device to perform actions. That is, the active support device starts to perform actions and issues an action flag at the beginning of the effective time window of the strategy, and ends to perform actions and issues a reset flag at the end of the effective time window of the strategy. Within the effective time window of the strategy, the active support device performs actions according to the active power target adjustment and reactive power target adjustment of each power conversion system in the energy storage power station. This is existing technology and will not be elaborated here. It should be noted that the real-time voltage / current signal at the common coupling point can be measured by installing voltage transformers and current transformers at the common coupling point. The common coupling point is the AC side point between the energy storage power station and the grid, so as to accurately reflect the actual voltage / current values ​​after grid connection and provide a data reference basis for the support control strategy output by the active support device. The support control strategy, action flag and reset flag output by the active support device are common knowledge in the art and are widely used in the existing power regulation field of energy storage power stations, which will not be elaborated here. Furthermore, the support control strategy used by the active support device when performing actions is defined as the baseline support control strategy, i.e., the original support control strategy. If the active support device generates a new support control strategy during the period when it is performing actions based on the baseline support control strategy, i.e. within the effective time window of the baseline support control strategy, the active support device generates a new support control strategy, i.e., a new support control strategy. This newly generated support control strategy is used as the reference support control strategy. The target adjustment amount in the baseline support control strategy is corrected by taking the largest value in the same direction based on the reference support control strategy. The remaining time interval for the active support device to perform actions under the baseline support control strategy is extracted. Its start time is the start time of the effective time window of the reference support control strategy, and its end time is the end time of the effective time window of the baseline support control strategy. Combined with the corrected target adjustment amount, a corrected support control strategy is constructed. The active support device re-executes the actions based on the corrected support control strategy and sends the action flag and the corrected support control strategy to the coordination controller when re-executing the actions. At the end of the action execution, a reset flag is sent to the coordination controller. The target adjustment includes active power target adjustment and reactive power target adjustment. The logic for correcting the active power target adjustment is as follows: For any power conversion system, the active power target adjustment is extracted from the benchmark support control strategy as the active power benchmark target adjustment of the power conversion system, and the active power target adjustment is extracted from the reference support control strategy as the active power reference target adjustment of the power conversion system. If both the active power benchmark target adjustment and the active power reference target adjustment are positive or negative, the value with the largest absolute value is selected as the corrected active power target adjustment of the power conversion system. Otherwise, no correction is performed, that is, the active power target adjustment of the power conversion system in the benchmark support control strategy is directly taken as the corrected active power target adjustment of the power conversion system. Similarly, for any power conversion system, the reactive power target adjustment amount of the power conversion system is extracted from the benchmark support control strategy as the reactive power benchmark target adjustment amount of the power conversion system, and the reactive power target adjustment amount of the power conversion system is extracted from the reference support control strategy as the reactive power reference target adjustment amount of the power conversion system. If both the reactive power benchmark target adjustment amount and the reactive power reference target adjustment amount of the power conversion system are positive or negative, the value with the largest absolute value is selected as the corrected reactive power target adjustment amount of the power conversion system. Otherwise, no correction is performed, that is, the reactive power target adjustment amount of the power conversion system in the benchmark support control strategy is directly taken as the corrected reactive power target adjustment amount of the power conversion system. In this way, the corrected reactive power target adjustment amount of each power conversion system is obtained. It should be noted that when correcting the target adjustment amount, this technical solution uses the arbitration principle of "taking the larger value in the same direction and blocking in opposite directions" to correct the target adjustment amount. Taking the larger value in the same direction is used to ensure that the strongest power demand is met, while blocking in opposite directions is used to protect against the execution of the latter strategy when there is a conflict between the previous and subsequent strategies. This ensures that the active support device will not cause the power oscillation and instability of the energy storage power station due to the conflict between the previous and subsequent strategies during the execution of the action.

[0020] S2, determine the latest action flag received by the coordination controller as the target action flag, and determine whether the coordination controller has received a return flag belonging to the same action as the target action flag up to the current time. If the determination result is no, proceed to step S3; otherwise, proceed to step S4. The target action flag can be determined based on the timestamps of each action flag received by the coordination controller. Here, the action flag with the latest timestamp up to the current moment, i.e., the most recently received action flag, is selected as the target action flag. The logic for determining whether the action flag and the return flag belong to the same action is as follows: each time the active support device performs an action, it generates a corresponding action ID, which can be generated based on a hash function. When the active support device sends out the action flag signal and the return flag signal, it embeds the corresponding action ID into them to provide a registration identifier for the action flag and the return flag. Subsequently, it is only necessary to observe whether the action IDs in the action flag signal and the return flag signal are consistent to determine whether they belong to the same action. It should be noted that the support control strategy issued and executed by the active support device focuses on the stability control of the energy storage power station, while the power allocation strategy issued by the energy management system focuses more on economic dispatch. Obviously, to avoid production accidents, the importance of stability control is generally higher than that of economic dispatch. If the judgment result is negative, it means that at the current moment, the active support device is executing actions based on the support control strategy to perform stability control on the energy storage power station. At this time, the focus of the coordination controller is on the analysis and processing of the support control strategy to ensure the stable operation of the energy storage power station. Therefore, the coordination controller is instructed not to receive the power allocation strategy to avoid interfering with the operation of the coordination controller. The selective rejection of the power allocation strategy by the coordination controller also reduces its own unnecessary energy consumption. If the judgment result is positive, it means that at the current moment, the active support device is not executing actions based on the support control strategy. This means that at the current moment, the energy storage power station does not need the support control strategy for stability control, and economic dispatch can be performed on the energy storage power station at the current moment. Therefore, the coordination controller is instructed to start receiving the power allocation strategy so that it can perform economic dispatch according to the power allocation strategy.

[0021] S3, starting from the current moment, trace back to the moment when the coordination controller first received the reset flag to form a support control time interval in which the coordination controller does not receive power allocation strategies. Within the support control time interval, the coordination controller outputs global support control commands for each support control strategy. It should be noted that the support control time interval starts from the current moment and ends at the moment when the coordination controller first receives the reset flag. During the support control time interval, the active support device is always in the process of execution. Therefore, during this support control time interval, the coordination controller only needs to consider the support control strategy and does not need to receive the power allocation strategy. The logic of the coordinating controller outputting global support control commands for each support control strategy is as follows: Within the support control time interval, the coordinating controller receives the support control strategy based on the strategy coverage method to update and replace the current support control strategy. Each time the current support control strategy is updated and replaced, the coordinating controller outputs a global support control command to the energy storage power station based on the updated and replaced current support control strategy. The global support control command includes the final target values ​​of active power and reactive power of each power conversion system in the energy storage power station. Specifically, it can refer to the strategy effective time window, the target adjustment amount of active power and reactive power of each power conversion system in the energy storage power station, and the acquisition of the real-time values ​​of active power and reactive power of each power conversion system in the energy storage power station. Furthermore, when the coordinating controller outputs the global support control command based on the support control strategy, it relaxes the rate constraint so that the active power and reactive power of each power conversion system can reach the final target value through one or fewer adjustments, thereby ensuring a rapid response to the stable control of the energy storage power station. It should be noted that the logic of receiving support control strategies using the strategy coverage method is as follows: when the coordinating controller receives a new round of support control strategies, it overwrites the previous round's support control strategy and uses it as the current support control strategy. This continues until the coordinating controller receives the next round of support control strategies, at which point it uses the next round's support control strategy to overwrite the previous one. This achieves the updating and replacement of the current support control strategy. The application of the strategy coverage method ensures that there is only one "current support control strategy" within the coordinating controller. That is, the coordinating controller only needs to generate global support control commands based on the "current support control strategy," avoiding the simultaneous existence of multiple intertwined support control strategies, which would cause the coordinating controller to frequently issue contradictory global support control commands, thus leading to power fluctuations in the energy storage power station. S4, starting from the current moment, trace back to the moment when the coordination controller first received the action flag, and use it as the power allocation time interval for the coordination controller to receive the power allocation strategy. Within the power allocation time interval, instruct the coordination controller to output the global power allocation command for each power allocation strategy. It should be noted that the power allocation time interval starts from the current moment and ends at the moment when the coordination controller first receives the action flag. During the power allocation time interval, the active support device is not in the process of action execution, and the energy storage power station does not need the support control strategy for stability control. That is, the energy storage power station can be economically dispatched during this power allocation time interval. Therefore, the coordination controller is instructed to receive the power allocation strategy during this power allocation time interval so that it can perform economic dispatch according to the power allocation strategy. The logic for the coordination controller to output a global power allocation command for each power allocation strategy is as follows: Within the power allocation time interval, the coordination controller receives the power allocation strategy based on the strategy coverage method to update and replace the current power allocation strategy. Each time the current power allocation strategy is updated and replaced, the coordination controller outputs a global power allocation command to the energy storage power station, satisfying rate constraints and exhibiting step-wise control, based on the updated current power allocation strategy. The global power allocation command includes the final target value of active power for each power conversion system of the energy storage power station, the single adjustment step size of active power, the active power adjustment interval, and the number of active power adjustment rounds; and the final target value of reactive power for each power conversion system of the energy storage power station, the single adjustment step size of reactive power, the reactive power adjustment interval, and the number of reactive power adjustment rounds. For details, refer to the power allocation strategy for each power conversion system within the energy storage power station. The target active power and target reactive power of the power conversion system, the real-time active power and real-time reactive power values ​​of each power conversion system in the energy storage power station, and the effective time window of the instruction in the adjustment constraint command are obtained. For example, the final target value in the global power allocation command is determined by the target value in the power allocation strategy, and the final adjustment value is determined based on the difference between the final target value and the real-time value. Then, combined with the rate constraint and the effective time window constraint of the instruction, the single adjustment step size, active power adjustment interval, and active power adjustment round of each power conversion system in the energy storage power station, as well as the single adjustment step size, reactive power adjustment interval, and reactive power adjustment round of each power conversion system in the energy storage power station, are determined by a suitable solver (such as quadratic programming, linear programming, robust optimization, etc., depending on the system model and performance requirements). This is common knowledge to those skilled in the art and will not be elaborated here. The rate constraint is as follows: 1) In the global power allocation command, the active power adjustment interval and reactive power adjustment interval of each power conversion system shall not be less than the preset adjustment interval threshold, so as to avoid the problem of power fluctuation of the energy storage station due to excessively frequent adjustment of the power conversion system. The adjustment interval threshold can be 1 second to avoid excessively frequent adjustment of the power conversion system. 2) In the global power allocation command, the single adjustment step size of the active power of each power conversion system shall not be greater than the product of its rated active power and the scaling factor, and the single adjustment step size of the reactive power of each power conversion system shall not be greater than the product of its rated reactive power and the scaling factor. The scaling factor is generally between 0.1 and 0.2, and can generally be 0.1, in order to avoid the problem of excessive fluctuation in the power of the energy storage station due to excessive adjustment amplitude. The rated active power and rated reactive power can be obtained from the product manual, and will not be elaborated here. It should be noted that the logic of receiving power allocation strategies using the strategy overriding method is as follows: when the coordination controller receives a new round of power allocation strategies, it overwrites the previous round's power allocation strategy and uses it as the current power allocation strategy. This continues until the coordination controller receives the next round of power allocation strategies, at which point it uses the next round's power allocation strategy to overwrite the previous one. This achieves the updating and replacement of the current power allocation strategy. The application of the strategy overriding method ensures that there is only one "current power allocation strategy" within the coordination controller. That is, the coordination controller only needs to generate global power allocation commands based on the "current power allocation strategy," avoiding the simultaneous existence of multiple intertwined power allocation strategies, which would cause the coordination controller to frequently issue contradictory global power allocation commands, thus leading to power fluctuations in the energy storage power station. It should be noted that, compared to traditional coordination controllers that only communicate with the active support device and are only responsible for processing support control signals, the coordination controller used in this technical solution needs to handle both the power allocation strategy from the energy management system and the support control strategy from the active support device. The performance parameters of the coordination controller used are shown in Table 1 below: Table 1. Performance Parameters of the Coordination Controller

[0022]

[0023] The present invention also provides a medium, which is a storage medium and stores a computer program thereon. When the computer program is executed by a processor, it implements the power fluctuation suppression method for energy storage power stations based on coordinated control in the first embodiment described above.

[0024] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0025] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0026] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0027] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for suppressing power fluctuations in an energy storage power station based on coordinated control, characterized in that, Includes the following steps: S1, based on the energy management system, issues a power allocation strategy, and based on the coordination controller, receives the support control strategy, action flag and reset flag from the active support device. If a new support control strategy is added during the active support device's execution of the action, the original support control strategy is modified by taking the largest value in the same direction based on the new support control strategy, and then the action is re-executed based on the modified support control strategy. S2, determine the latest action flag received by the coordination controller as the target action flag, and determine whether the coordination controller has received a return flag belonging to the same action as the target action flag up to the current time. If the determination result is no, proceed to step S3; otherwise, proceed to step S4. S3, starting from the current moment, trace back to the moment when the coordination controller first received the reset flag to form a support control time interval in which the coordination controller does not receive power allocation strategies. Within the support control time interval, the coordination controller outputs the corresponding global support control command for each support control strategy. S4, starting from the current moment, trace back to the moment when the coordination controller first received the action flag, and use it as the power allocation time interval for the coordination controller to receive the power allocation strategy. Within the power allocation time interval, instruct the coordination controller to output the corresponding global power allocation command for each power allocation strategy.

2. The method for suppressing power fluctuations in an energy storage power station based on coordinated control according to claim 1, characterized in that, The power allocation strategy generation logic is as follows: The on-site platform of the energy storage power station receives and analyzes safety event data from automatic safety devices, real-time power generation / power control information from automatic generation control substations, and voltage / reactive power control information from automatic voltage control substations to generate adjustment constraint instructions, which include global active power targets, global reactive power targets, and SOC constraint intervals. Based on the energy management system receiving and analyzing the adjustment constraint instructions, a power allocation strategy is generated and output. The power allocation strategy includes the target active power and target reactive power of each power conversion system within the energy storage power station.

3. The method for suppressing power fluctuations in an energy storage power station based on coordinated control according to claim 2, characterized in that: The energy management system uses an instruction overlay method to receive adjustment constraint instructions, thereby updating and replacing the current adjustment constraint instructions. After each round of updating and replacing the current adjustment constraint instructions, the energy management system immediately outputs a power allocation strategy based on the current adjustment constraint instructions. Then, according to a fixed strategy sampling frequency, a power allocation strategy is also output based on the current adjustment constraint instructions at each subsequent strategy sampling point until the energy management system receives the next adjustment constraint instruction.

4. The method for suppressing power fluctuations in an energy storage power station based on coordinated control according to claim 1, characterized in that, The generation logic of the support control strategy, action flag, and reset flag is as follows: The active support device receives and analyzes the power allocation strategy from the energy management system, the real-time power generation / power control information from the automatic generation control substation, and the real-time voltage / current signal from the common coupling point, generates the support control strategy, and executes the action accordingly. The active support device synchronously transmits the support control strategy and the action flag at the start of the action to the coordination controller, and transmits the reset flag to the coordination controller at the end of the action. The support control strategy includes the effective time window of the strategy, the active power target adjustment amount and the reactive power target adjustment amount of each power conversion system in the energy storage power station, and the target adjustment amount is positive to indicate an increase and negative to indicate a decrease.

5. The method for suppressing power fluctuations in an energy storage power station based on coordinated control according to claim 4, characterized in that: The support control strategy used by the active support device when performing actions is defined as the baseline support control strategy, i.e., the original support control strategy. If the active support device generates a new support control strategy during the execution of actions based on the baseline support control strategy, i.e., a new support control strategy is added, this newly generated support control strategy is used as the reference support control strategy. The target adjustment amount in the baseline support control strategy is corrected by taking the largest value in the same direction based on the reference support control strategy. The remaining time interval of the active support device's actions under the baseline support control strategy is extracted, and the corrected target adjustment amount is combined to construct the corrected support control strategy. The active support device re-executes the actions based on the corrected support control strategy, and sends the action flag and the corrected support control strategy at the time of re-execution to the coordination controller. At the end of the action execution, a reset flag is sent to the coordination controller.

6. The method for suppressing power fluctuations in an energy storage power station based on coordinated control according to claim 5, characterized in that: For the remaining time interval of the action execution, its start time is the start time of the effective time window of the reference support control strategy, and its end time is the end time of the effective time window of the benchmark support control strategy.

7. The method for suppressing power fluctuations in an energy storage power station based on coordinated control according to claim 5, characterized in that: The target adjustment amount includes active power target adjustment amount and reactive power target adjustment amount. The logic for correcting the active power target adjustment amount is as follows: For any power conversion system, the active power target adjustment amount of the power conversion system is extracted from the benchmark support control strategy as the active power benchmark target adjustment amount of the power conversion system, and the active power target adjustment amount of the power conversion system is extracted from the reference support control strategy as the active power reference target adjustment amount of the power conversion system. If both the active power benchmark target adjustment amount and the active power reference target adjustment amount of the power conversion system are positive or negative, the value with the largest absolute value is selected as the corrected active power target adjustment amount of the power conversion system. Otherwise, no correction is performed, that is, the active power target adjustment amount of the power conversion system in the benchmark support control strategy is directly taken as the corrected active power target adjustment amount of the power conversion system. Similarly, the corrected reactive power target adjustment amount of each power conversion system is calculated and obtained.

8. The method for suppressing power fluctuations in an energy storage power station based on coordinated control according to claim 1, characterized in that, The logic of the coordination controller outputting the corresponding global support control command for each support control strategy is as follows: During the support control time interval, the coordination controller receives the support control strategy based on the strategy coverage method to realize the update and replacement of the current support control strategy. Each time the update and replacement of the current support control strategy is completed, the coordination controller outputs a global support control command to the energy storage power station based on the updated and replaced current support control strategy. The global support control command includes the final target value of active power and the final target value of reactive power of each power conversion system of the energy storage power station. The coordination controller releases the rate constraint when outputting the global support control command based on the support control strategy.

9. The method for suppressing power fluctuations in an energy storage power station based on coordinated control according to claim 1, characterized in that, The logic of the coordination controller outputting the corresponding global power allocation command for each power allocation strategy is as follows: During the power allocation time interval, the coordination controller receives the power allocation strategy based on the strategy coverage method to realize the update and replacement of the current power allocation strategy. Each time the update and replacement of the current power allocation strategy is completed, the coordination controller outputs a global power allocation command that meets the rate constraint and is in step control to the energy storage power station based on the updated and replaced current power allocation strategy. The global power allocation command includes the final target value of active power of each power conversion system of the energy storage power station, the single adjustment step size of active power, the adjustment interval of active power and the number of active power adjustment rounds, as well as the final target value of reactive power of each power conversion system of the energy storage power station, the single adjustment step size of reactive power, the adjustment interval of reactive power and the number of reactive power adjustment rounds. The rate constraint is as follows: 1) In the global power allocation command, the active power adjustment interval and reactive power adjustment interval of each power conversion system shall not be less than the preset adjustment interval threshold. 2) In the global power allocation command, the single adjustment step size of the active power of each power conversion system is no greater than the product of its rated active power and the scaling factor, and the single adjustment step size of the reactive power of each power conversion system is no greater than the product of its rated reactive power and the scaling factor. The scaling factor is a positive value less than 1.

10. A medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the power fluctuation suppression method for energy storage power stations based on coordinated control as described in any one of claims 1-9.

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