Configuration method of energy storage system with high transient overload capacity and control method of energy storage system

Abstract

The present invention relates to the technical field of power grid control, and specifically discloses a configuration method for an energy storage system with high transient overload capacity and a control method for the energy storage system, including: obtaining the load information of the current power grid; determining the expected overload capacity and the first configuration of the lithium battery system based on the load information; determining the circuit parameters of the voltage conversion circuit based on the expected overload capacity and the first configuration; determining the second configuration of the supercapacitor system based on the expected overload capacity, the first configuration, and the circuit parameters; generating a configuration result of the energy storage system based on the first configuration, the circuit parameters, and the second configuration. By improving the existing energy storage system and combining with the improved control method, the transient overload capacity of the energy storage system can be effectively improved to meet the actual operation requirements of the power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid control, and particularly relates to a configuration method for an energy storage system with high transient overload capacity and a control method for the energy storage system. Background Art

[0002] With the continuous development of new energy technologies, more and more new energy sources are connected to the power grid to provide more energy support for the power grid. However, in the actual application process, the connection of new energy brings more interference to the power grid while providing more energy support.

[0003] In common new energy power generation scenarios, such as wind and solar power generation scenarios, due to the random fluctuations of wind and solar power generation, it has become an important obstacle to their application in the power grid. To solve this technical problem, technicians propose to configure an energy storage system for the wind and solar power generation system to solve this technical problem. Existing energy storage systems include lithium battery energy storage systems, lead-acid battery energy storage systems, supercapacitor systems, and flywheel systems, etc. Among them, lithium battery energy storage systems are widely used.

[0004] In the actual application process, although the lithium battery energy storage system can store or output a large amount of energy, the randomness of wind and solar power generation causes power grid fluctuations. At this time, the energy storage system needs to have high transient overload capacity, while the existing lithium battery energy storage system does not have the above ability. Although technicians thought of further configuring a supercapacitor for the lithium battery energy storage system to achieve high transient overload capacity, due to the low power density of the supercapacitor, if the configuration amount of the supercapacitor is not increased, it cannot provide overload capacity for a longer time; if the configuration amount of the supercapacitor is increased, the operation cost will be greatly increased, causing certain troubles to enterprises. Summary of the Invention

[0005] In order to overcome the above technical problems existing in the prior art, an embodiment of the present invention provides a configuration method for an energy storage system with high transient overload capacity and a control method for the energy storage system. By improving the existing energy storage system and combining with the improved control method, the transient overload capacity of the energy storage system is effectively improved to meet the actual operation requirements of the power grid.

[0006] To achieve the above object, an embodiment of the present invention provides a configuration method for an energy storage system with high transient overload capacity, the method comprising: obtaining the load information of the current power grid; determining the expected overload capacity and the first configuration of the lithium battery system based on the load information; determining the circuit parameters of the voltage conversion circuit based on the expected overload capacity and the first configuration; determining the second configuration of the supercapacitor system based on the expected overload capacity, the first configuration and the circuit parameters; generating a configuration result of the energy storage system based on the first configuration, the circuit parameters and the second configuration.

[0007] Preferably, determining the expected overload capacity based on the load information includes: extracting extreme data from the load information to obtain extreme load data; performing a conventional analysis on the extreme load data to obtain conventional extreme load data; extracting features from the conventional extreme load data to obtain extreme load features; determining the expected extreme power and the expected extreme response time based on the extreme load features; and generating the expected overload capacity based on the expected extreme power and the expected extreme response time.

[0008] Preferably, the voltage conversion circuit includes a bidirectional DC / DC and a three-phase inverter. Determining the circuit parameters of the voltage conversion circuit based on the expected overload capacity and the first configuration includes: determining the first limit overload power and the first overload time of the lithium battery system based on the first configuration; matching the expected overload capacity based on the first limit overload power and the first overload time to generate a matching result; determining the first configuration parameters of the bidirectional DC / DC and the second configuration parameters of the three-phase inverter based on the matching result; and generating the circuit parameters of the voltage conversion circuit based on the first configuration parameters and the second configuration parameters.

[0009] Preferably, determining the second configuration of the supercapacitor system based on the expected overload capacity, the first configuration, and the circuit parameters includes: determining the overload power deviation and the overload time deviation of the lithium battery system based on the expected overload capacity, the first configuration, and the circuit parameters; determining the second limit overload power and the second overload time based on the overload power deviation and the overload time deviation; and determining the second configuration of the supercapacitor system based on the second limit overload power and the second overload time.

[0010] Preferably, the method further includes: determining the total costs of the lithium battery system and the supercapacitor system based on the first configuration and the second configuration; determining the expected cost; determining the first configuration interval corresponding to the first configuration and the second configuration interval corresponding to the second configuration based on the expected cost and the total costs; analyzing the first configuration interval and the second configuration interval based on the gradient descent algorithm to generate an optimized first configuration and an optimized second configuration; and generating the configuration result of the energy storage system based on the optimized first configuration, the circuit parameters, and the optimized second configuration.

[0011] Further, the present invention also provides a control method for an energy storage system. The control method is applied to an energy storage system with high transient overload capacity, and the control method includes: obtaining historical load information of the current power grid; determining abnormal fluctuation information of the current power grid based on the historical load information, where the abnormal fluctuation information includes abnormal fluctuation frequency, abnormal fluctuation power, and abnormal fluctuation time; judging whether the energy storage system has a corresponding overload response ability based on the abnormal fluctuation information; if so, generating pre-overload information corresponding to the abnormal fluctuation period based on the abnormal fluctuation frequency and the abnormal fluctuation power; and controlling the energy storage system to perform corresponding transient overload operations based on the pre-overload information.

[0012] Preferably, the judging whether the energy storage system has a corresponding overload response ability based on the abnormal fluctuation information includes: obtaining the limit response parameters of the energy storage system, where the limit response parameters include limit response power and corresponding limit response time; judging whether the limit response power and the limit response time meet the response requirements of the abnormal fluctuation information; if the limit response power and the limit response time meet the response requirements, determining that the energy storage system has an overload response ability; otherwise: determining a critical response interval, adjusting the limit response parameters based on the critical response interval to generate adjusted response parameters; judging whether the adjusted response parameters meet the response requirements of the abnormal fluctuation information; if the adjusted response parameters meet the response requirements, determining that the energy storage system has an overload response ability; if the adjusted response parameters do not meet the response requirements, determining that the energy storage system does not have an overload response ability.

[0013] Preferably, the energy storage system includes a lithium battery system and a supercapacitor system. The determining the critical response interval includes: obtaining the first power configuration and the first response time of the lithium battery system, and obtaining the second power configuration and the second response time of the supercapacitor system; determining the fluctuation type based on the abnormal fluctuation information, and obtaining the average charging power of the current power grid; determining the first safety power threshold corresponding to the fluctuation type of the lithium battery system and the second safety power threshold corresponding to the fluctuation type of the supercapacitor system; determining the second over-limit configuration of the supercapacitor system based on the second power configuration, the average charging power, the second safety power threshold, and the second response time; determining the first over-limit configuration of the lithium battery system based on the second over-limit configuration, the first power configuration, the average charging power, the first safety power threshold, and the first response time; co-optimizing the first over-limit configuration and the second over-limit configuration based on the first temperature rise curve of the lithium battery system and the second temperature rise curve of the supercapacitor system to generate corresponding first optimized configuration and second optimized configuration; and determining the critical response interval based on the first optimized configuration and the second optimized configuration.

[0014] Preferably, generating pre-overload information corresponding to the abnormal fluctuation period based on the abnormal fluctuation frequency and the abnormal fluctuation power includes: when the limit response power and the limit response time meet the response requirements: obtaining the current first capacity of the lithium battery system and the current second capacity of the supercapacitor system; pre-adjusting the first capacity and the second capacity based on the abnormal fluctuation frequency, the abnormal fluctuation power, and the abnormal fluctuation period to generate corresponding pre-adjusted first capacity and pre-adjusted second capacity; generating corresponding pre-overload information based on the pre-adjusted first capacity and the pre-adjusted second capacity; when the limit response power and the limit response time do not meet the response requirements: pre-adjusting the first capacity and the second capacity based on the critical response interval, the abnormal fluctuation frequency, the abnormal fluctuation power, and the abnormal fluctuation period to generate corresponding pre-adjusted third capacity and pre-adjusted fourth capacity; generating corresponding pre-overload information based on the pre-adjusted third capacity and the pre-adjusted fourth capacity.

[0015] Preferably, the control method further includes: after performing the transient overload operation, determining whether the abnormal fluctuation of the current power grid has ended; when the abnormal fluctuation of the current power grid has ended, obtaining the first normal capacity of the lithium battery system and the second normal capacity of the supercapacitor system; controlling the lithium battery system to perform a corresponding capacity recovery operation based on the first normal capacity, and controlling the supercapacitor system to perform a corresponding capacity recovery operation based on the second normal capacity.

[0016] Through the technical solution provided by the present invention, the present invention has at least the following technical effects:

[0017] On the one hand, by improving the existing energy storage system configured for the power grid, a lithium battery system with voltage active regulation ability is combined with a supercapacitor system that can respond quickly to achieve stronger high transient overload ability.

[0018] On the other hand, by analyzing and predicting the fluctuation data of the power grid, and performing short-term and extreme pre-regulation on the improved energy storage system according to the prediction situation, the transient overload ability of the energy storage system is further improved, enabling its transient overload performance to be exerted to the extreme, thereby effectively meeting the actual operation requirements of the power grid.

[0019] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific implementation part. Description of the Drawings

[0020] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation to the embodiments of the present invention. In the accompanying drawings:

[0021] Figure 1 is a specific implementation flowchart of a configuration method for an energy storage system with high transient overload capacity provided by an embodiment of the present invention;

[0022] Figure 2 is a specific implementation flowchart of a control method for an energy storage system provided by an embodiment of the present invention. Specific Embodiments

[0023] The following will detail the specific embodiments of the embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the embodiments of the present invention and are not used to limit the embodiments of the present invention.

[0024] In the embodiments of the present invention, the terms "system" and "network" can be used interchangeably. "Plural" means two or more. In view of this, in the embodiments of the present invention, "plural" can also be understood as "at least two". "And / or" describes the association relationship of associated objects and indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " generally represents an "or" relationship between the associated objects before and after, unless otherwise specified. In addition, it should be understood that in the description of the embodiments of the present invention, words such as "first" and "second" are only used for the purpose of distinguishing descriptions and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0025] Please refer to Figure 1 , an embodiment of the present invention provides a configuration method for an energy storage system with high transient overload capacity, and the method includes:

[0026] S10: Obtain the load information of the current power grid;

[0027] S20: Determine the expected overload capacity and the first configuration of the lithium battery system based on the load information;

[0028] S30: Determine the circuit parameters of the voltage conversion circuit based on the expected overload capacity and the first configuration;

[0029] S40: Determine the second configuration of the supercapacitor system based on the expected overload capacity, the first configuration, and the circuit parameters;

[0030] S50: Generate a configuration result of the energy storage system based on the first configuration, the circuit parameters, and the second configuration.

[0031] In a possible implementation, first, obtain the load information of the current power grid. This load information can be the historical load information of the current power grid within a certain period. Since the electricity consumption situation in the power consumption areas covered by the power grid generally does not change much in a short period, the abnormal electricity consumption situation of the current power grid can be evaluated more accurately based on this historical load information. At this time, determine the expected overload capacity according to this load information.

[0032] In the embodiment of the present invention, determining the expected overload capacity based on the load information includes: extracting extreme data from the load information to obtain extreme load data; performing routine analysis on the extreme load data to obtain conventional extreme load data; extracting features from the conventional extreme load data to obtain extreme load features; determining the expected extreme power and the expected extreme response time based on the extreme load features; and generating the expected overload capacity based on the expected extreme power and the expected extreme response time.

[0033] In a possible implementation, when extracting extreme data from the load information, specifically, analyze the normal electricity consumption information in the load information to filter out the normal electricity consumption information and only retain extreme load data such as overvoltage, undervoltage, and overcurrent. Since the extreme load data also includes non-routine data, for example, a large-scale power grid power outage is a less frequent accidental event, and such an event will cause a large-scale impact on the power grid. The power compensation required for such an event cannot be compensated by a conventional energy storage system, so it does not need to be considered within the range of the overload response ability. Therefore, in order to accurately obtain the overload capacity matching the energy storage system, after performing routine analysis on the extreme load data, remove the non-routine extreme load data therein and obtain the conventional extreme load data.

[0034] At this time, extract features from the conventional extreme load data to obtain extreme load features. The extreme load features include but are not limited to features such as extreme load peaks, extreme load change trends, and extreme load durations. Then, determine the expected extreme power and the expected extreme response time according to the extreme load features. For example, in one embodiment, when the wind and solar power generation of a power station drops suddenly, causing the power grid frequency to drop rapidly (such as the frequency is lower than 49.5 Hz), the required power for corresponding compensation operations can be determined according to this extreme load data, that is, determine the expected extreme power. After analyzing and determining the expected extreme power and the expected extreme response time, generate the expected overload capacity. For example, in another embodiment, when equipment such as rolling mills and stamping presses in a steel plant start, the instantaneous power reaches 5-10 times the rated load and lasts for 1000 ms. At this time, the energy storage system needs to at least have the high transient overload capacity corresponding to the above parameters to avoid impact on the power grid.

[0035] Meanwhile, based on the above load information, the first configuration of the lithium battery system can be further determined. In the embodiments of the present invention, since the lithium battery system has a high energy density and can meet the overload response in minutes, the lithium battery system is preferentially configured. Specifically, the maximum overload demand of the energy storage system can be determined according to the load information, such as the maximum overload power demand, the maximum overload current demand, the maximum overload frequency demand, etc. The capacity of the lithium battery system is configured according to the maximum overload demand, that is, the first configuration of the lithium battery system is determined.

[0036] However, in the prior art, the overload compensation ability is often directly provided for the power grid by configuring the lithium battery system. Therefore, its overload compensation ability is limited by the configuration parameters of the lithium battery system. If a higher overload compensation ability is desired, more lithium batteries need to be configured, which will lead to a rapid increase in cost and reduce the operating efficiency of the enterprise.

[0037] To solve the above technical problems, after determining the first configuration of the lithium battery system, a voltage conversion circuit is further configured for the lithium battery system. In the embodiments of the present invention, the voltage conversion circuit includes a bidirectional DC / DC and a three-phase inverter. Through the bidirectional DC / DC, the voltage of the lithium battery system can be adaptively and dynamically adjusted, so as to allow overload output to the power grid or receive overload input from the power grid with a large power. By configuring the three-phase inverter, efficient energy conversion can be achieved, and fast and effective dynamic supports such as power grid synchronization and harmonic suppression can be provided for the power grid.

[0038] Determining the circuit parameters of the voltage conversion circuit based on the expected overload capacity and the first configuration includes: determining the first limit overload power and the first overload time of the lithium battery system based on the first configuration; matching the expected overload capacity based on the first limit overload power and the first overload time to generate a matching result; determining the first configuration parameters of the bidirectional DC / DC and the second configuration parameters of the three-phase inverter based on the matching result; generating the circuit parameters of the voltage conversion circuit based on the first configuration parameters and the second configuration parameters.

[0039] In a possible implementation manner, the first limit overload power and the first overload time of the lithium battery system can be determined according to the first configuration of the lithium battery system. For example, in one embodiment, the currently configured lithium battery system can meet the 2-5 times overload output for 10s - 5min. When outputting, the maximum current that can be output is, for example, 100A. At this time, it is matched with the expected overload capacity. For example, in the embodiment of the present invention, among the conventional extreme load data of the current power grid, there is a need for power compensation with an input current of 200A for 30s to meet the abnormal fluctuation demand. Therefore, the above first limit overload power may not be able to meet the demand of the expected overload capacity. Based on this, the first configuration parameters of the DC / DC are configured. For example, through the configured DC / DC, the voltage of the lithium battery system can be reduced from 800V to 400V, so as to increase the maximum output current from 100A to 200A in a short time to meet the actual power compensation demand of the power grid.

[0040] After determining the first configuration parameters of the DC / DC and the second configuration parameters of the three-phase inverter, the circuit parameters of the voltage conversion circuit are generated, and the corresponding hardware configuration is performed.

[0041] In the embodiment of the present invention, by further configuring a voltage conversion circuit in the lithium battery system to dynamically adjust the voltage and current parameters of the lithium battery during operation, the power compensation ability of the inherent lithium battery system for the power grid can be further improved without increasing additional costs to meet the actual demand. It should be noted that a corresponding heat dissipation design for the above voltage conversion circuit also needs to be configured. For example, a corresponding liquid cooling heat dissipation structure is set for the lithium battery system, and a corresponding heat dissipation design is designed for the three-phase inverter, etc. Since it does not belong to the technical problems concerned in the embodiment of the present invention, it will not be elaborated here too much.

[0042] At this time, the configuration of the supercapacitor system is further determined. Since there are still a large number of compensation demands at the ms level during the operation of the power grid, and the lithium battery system cannot achieve ms-level overload compensation due to insufficient power density, a supercapacitor system is further configured on the basis of the lithium battery system to meet the high-transient overload demand. However, the energy density of the supercapacitor is small and cannot meet the long-term compensation demand. Therefore, how to determine its optimal configuration ratio becomes a difficult problem.

[0043] In the embodiment of the present invention, determining the second configuration of the supercapacitor system based on the expected overload capacity, the first configuration, and the circuit parameters includes: determining the overload power deviation and the overload time deviation of the lithium battery system based on the expected overload capacity, the first configuration, and the circuit parameters; determining the second limit overload power and the second overload time based on the overload power deviation and the overload time deviation; determining the second configuration of the supercapacitor system based on the second limit overload power and the second overload time.

[0044] In a possible implementation, after preferentially configuring the lithium battery system, the supercapacitor system is further configured according to the expected overload capacity and circuit parameters. Specifically, according to the expected overload capacity, the first configuration of the lithium battery system, and the circuit parameters, the overload power deviation of the lithium battery system can be determined. For example, in the embodiments of the present invention, according to the determined expected overload capacity, the maximum power compensation requirement can be determined. On this basis, after deducting the maximum power compensation that the lithium battery system can output, the maximum power that the supercapacitor system needs to be configured can be obtained. At the same time, according to the expected extreme response time required by the expected overload capacity, for example, in one embodiment, it is required to respond within 100 ms and maintain the overload output for 5 min, while the lithium battery system can only achieve sufficient overload support after 2 s. Therefore, it is required that the supercapacitor system can have a corresponding overload compensation ability within the time range of 100 ms - 2 s, and at the same time, it is output in cooperation with the lithium battery system to achieve a high transient overload of 100 ms - 5 min. Based on this, the second limit overload power and the second overload time that the supercapacitor system needs to possess can be determined, that is, the second configuration of the supercapacitor system is determined.

[0045] Finally, according to the first configuration of the lithium battery system, the circuit parameters of the voltage conversion circuit, and the second configuration of the supercapacitor system, an energy storage system with high transient overload capacity can be constructed, which can not only effectively meet the instantaneous response requirements during the actual operation of the power grid, but also extend the power response time to a certain extent, thereby effectively reducing the impact of accidents on the power grid and providing reliable support for the stable operation of the power grid.

[0046] In the actual application process, in order to meet the fluctuation stabilization effect of the power grid, the configured lithium battery system and supercapacitor system may both be in the MW level, so the cost is relatively high. If simply configured according to the priority of the lithium battery system and supplemented by the supercapacitor system, it may lead to a relatively high project cost and does not meet the actual needs of the enterprise.

[0047] To solve the above technical problems, in the embodiments of the present invention, the method further includes: determining the total cost of the lithium battery system and the supercapacitor system based on the first configuration and the second configuration; determining the expected cost; determining a first configuration interval corresponding to the first configuration and a second configuration interval corresponding to the second configuration based on the expected cost and the total cost; analyzing the first configuration interval and the second configuration interval based on the gradient descent algorithm to generate an optimized first configuration and an optimized second configuration; and generating a configuration result of the energy storage system based on the optimized first configuration, the circuit parameters, and the optimized second configuration.

[0048] In a possible implementation, after initially determining the first configuration of the lithium battery system and the second configuration of the supercapacitor system, the total cost of the lithium battery system and the supercapacitor system can be determined. Of course, the total cost can be further determined in combination with the cost of the voltage conversion circuit. At this time, the expected cost is further determined, and this expected cost can be pre-determined by the management personnel according to the expected rate of return or operating cost. Then, based on this expected cost and the total cost, the first configuration range corresponding to the first configuration is determined, that is, with the first configuration as the reference and the configurable cost range as the floating range, the first configuration range is determined; based on the same principle, the second configuration range corresponding to the second configuration is determined, and then the above first configuration range and second configuration range are analyzed according to the gradient descent algorithm. Specifically, data analysis is performed with the minimum cost as the goal to determine the optimized first configuration and optimized second configuration with the lowest total cost, and finally the configuration result of the energy storage system is determined.

[0049] In the embodiments of the present invention, by further optimizing the determined configuration result of the energy storage system based on the economy of the design, an energy storage system configuration with the best economy is generated, realizing the minimization of the operating cost on the basis of meeting the high transient overload capacity, and meeting the actual needs of enterprises.

[0050] After configuring an energy storage system with high transient overload capacity and applying it, during the actual application process, the sudden situations faced by the power grid may be relatively severe. Technicians hope that on the basis of not adding additional configurations, the existing energy storage system can have stronger transient overload capacity. Since in the application process of the existing energy storage system, the transient overload response is mainly divided into two ways: active and passive. Among them, the active way is that when it detects abnormal power consumption in the current power grid, it will actively overload and output the corresponding power to compensate the power grid; while the passive way is for sudden or occasional abnormal power consumption, and the energy storage system automatically performs transient overload response. Therefore, in order to ensure that the energy storage system has sufficient power grid regulation ability, the capacity in the energy storage system is often fixedly configured in the range of 40%-65%. Therefore, technicians conceive to make improvements based on the above technologies.

[0051] On the other hand, please refer to Figure 2 , the embodiments of the present invention also provide a control method for an energy storage system. The control method is applied to an energy storage system with high transient overload capacity, and the control method includes:

[0052] S01: Obtain the historical load information of the current power grid;

[0053] S02: Determine the abnormal fluctuation information of the current power grid based on the historical load information, and the abnormal fluctuation information includes abnormal fluctuation frequency, abnormal fluctuation power and abnormal fluctuation time;

[0054] S03: Determine whether the energy storage system has corresponding overload response capabilities based on the abnormal fluctuation information;

[0055] S04: If so, generate pre-overload information corresponding to the abnormal fluctuation period based on the abnormal fluctuation frequency and the abnormal fluctuation power;

[0056] S05: Control the energy storage system to perform corresponding transient overload operations based on the pre-overload information.

[0057] In a possible implementation manner, when applying an energy storage system with high transient overload capabilities to a target power grid, first obtain the historical load information of the current power grid. According to this historical load information, the abnormal fluctuation information of the current power grid can be determined, and the abnormal fluctuation information includes, but is not limited to, abnormal fluctuation frequency, abnormal fluctuation power, and abnormal fluctuation time. At this time, first determine whether the energy storage system has corresponding overload response capabilities according to the above abnormal fluctuation information.

[0058] In the embodiments of the present invention, determining whether the energy storage system has corresponding overload response capabilities based on the abnormal fluctuation information includes: obtaining the limit response parameters of the energy storage system, where the limit response parameters include the limit response power and the corresponding limit response time; determining whether the limit response power and the limit response time meet the response requirements of the abnormal fluctuation information; if the limit response power and the limit response time meet the response requirements, determine that the energy storage system has overload response capabilities; otherwise: determine the critical response interval, adjust the limit response parameters based on the critical response interval to generate adjusted response parameters; determine whether the adjusted response parameters meet the response requirements of the abnormal fluctuation information; if the adjusted response parameters meet the response requirements, determine that the energy storage system has overload response capabilities; if the adjusted response parameters do not meet the response requirements, determine that the energy storage system does not have overload response capabilities.

[0059] Specifically, according to the configuration of the energy storage system, obtain the limit response parameters of the energy storage system, where the limit response parameters include, but are not limited to, the limit response power and the corresponding limit response time. For example, in one embodiment, it is required to output a power of 2 MW within 10 s; in another embodiment, it is required to compensate for the starting impact of a 5 MW industrial device within 100 ms. According to the limit response parameters of the energy storage system, it can be determined whether it meets the response requirements of the abnormal fluctuation information.

[0060] In one embodiment, the current power grid is affected by fluctuations due to a sudden drop in the output of wind-solar generating units caused by the occlusion of small clouds, but the response requirements corresponding to this fluctuation impact are within the limit response power and limit response time of the energy storage system. Therefore, it can be determined that the energy storage system has high transient overload response capabilities for this power consumption abnormality.

[0061] In another embodiment, the centralized charging of electric vehicles in a certain area causes a short-term (minute-level) increase in the grid load and causes a large fluctuation in the grid. For example, it causes a certain degree of decrease in the bus voltage of the grid in this area. For the configured energy storage system, the response demand corresponding to this fluctuation has exceeded its sufficient response capacity. At this time, in order to achieve stronger transient overload capacity without adding additional configurations, further, the critical response interval of the energy storage system is determined.

[0062] In the embodiment of the present invention, the energy storage system includes a lithium battery system and a supercapacitor system. The determination of the critical response interval includes: obtaining the first power configuration and the first response time of the lithium battery system, and obtaining the second power configuration and the second response time of the supercapacitor system; determining the fluctuation type based on the abnormal fluctuation information, and obtaining the average charging power of the current grid; determining the first safety power threshold corresponding to the fluctuation type of the lithium battery system and the second safety power threshold corresponding to the fluctuation type of the supercapacitor system; determining the second over-limit configuration of the supercapacitor system based on the second power configuration, the average charging power, the second safety power threshold and the second response time; determining the first over-limit configuration of the lithium battery system based on the second over-limit configuration, the first power configuration, the average charging power, the first safety power threshold and the first response time; optimizing the first over-limit configuration based on the first temperature rise curve of the lithium battery system to generate a first optimized configuration, and optimizing the second over-limit configuration based on the second temperature rise curve of the supercapacitor system to generate a second optimized configuration; determining the critical response interval based on the first optimized configuration and the second optimized configuration.

[0063] In a possible implementation manner, first, obtain the first power configuration and the first response time of the lithium battery system, and the second power configuration and the second response time of the supercapacitor system. At the same time, determine the fluctuation type according to the abnormal fluctuation information. In the embodiment of the present invention, the fluctuation types include power consumption fluctuations and charging fluctuations, that is, grid fluctuations caused by abnormal power consumption (such as the instantaneous start of industrial equipment, the interruption of output of wind and solar power generation, etc.) and grid fluctuations caused by abnormal charging (such as a sudden increase in wind power generation caused by a sudden strong wind). And obtain the average charging power of the current grid, which is the average power obtained by the energy storage system charging from the grid under normal conditions, that is, determine the charging capacity of the grid for the energy storage system under normal conditions.

[0064] At this time, further, the first safety power threshold corresponding to the lithium battery system and the fluctuation type can be determined. For example, in one embodiment, the fluctuation type is power consumption fluctuation, that is, at this time, the lithium battery system needs to perform transient overloading discharge to stabilize the grid fluctuation. In this case, it is only necessary to ensure that the capacity or the output power of the energy storage system is within the allowable safety range (for example, ensuring that the capacity of the energy storage system is not less than 20%); in another embodiment, the fluctuation type is charging fluctuation, that is, at this time, the lithium battery system needs to perform transient overloading charge to stabilize the grid fluctuation. In this case, it is only necessary to ensure that the capacity of the energy storage system is not greater than 100%. Thus, the first safety power threshold of the lithium battery system is determined. Based on the same principle, the second safety power threshold of the supercapacitor system can be determined.

[0065] Since the grid fluctuates, the fluctuation should be processed with the fastest speed. Therefore, the over-limit configuration of the supercapacitor is preferentially determined. Specifically, the second over-limit configuration of the supercapacitor system is determined according to the second power configuration, the average charging power, the second safety power threshold, and the second response time. For example, in this embodiment, if the grid has a power consumption fluctuation, the capacity of the supercapacitor can be determined to be increased from 65% to 95% in a short time according to the calculation of the above parameters to better respond to the grid fluctuation, that is, the second over-limit configuration of the supercapacitor system is determined. On this basis, the first over-limit configuration of the lithium battery system is further determined. For example, on the basis that the capacity of the supercapacitor system is increased to 95%, according to the intensity and duration of the current grid fluctuation, it can be determined that the capacity of the lithium battery system is increased from 50% to 70%, which can meet the corresponding requirements, that is, the first over-limit configuration of the lithium battery system is determined.

[0066] However, in the actual application process, although the energy storage system configuration with the strongest transient overloading ability can be determined by the above method, when the lithium battery system and the supercapacitor system are severely charged and discharged, a large amount of heat will be quickly generated. If not managed in time, it will lead to a thermal runaway event and even cause a safety accident.

[0067] Therefore, in the embodiment of the present invention, after the first over-limit configuration of the lithium battery system and the second over-limit configuration of the supercapacitor system are initially determined, the first over-limit configuration and the second over-limit configuration are further optimized in coordination according to the first temperature rise curve of the lithium battery system and the second temperature rise curve of the supercapacitor system, so as to keep the temperatures of both the lithium battery system and the supercapacitor system within the thermal runaway range on the basis of achieving the strongest transient overloading ability and ensure sufficient use safety.

[0068] Finally, determine the critical response interval based on the determined first optimized configuration and second optimized configuration, that is, on the basis of the original ultimate transient overload capacity of the energy storage system, further adjust it according to the critical response interval to expand its relevant limit parameters, so as to obtain a higher transient overload capacity and meet higher requirements.

[0069] In subsequent application processes, adjust the limit response parameters of the energy storage system according to the critical response interval, and further determine whether the adjusted response parameters meet the response requirements of the abnormal fluctuation information. If they can be met, perform the corresponding transient overload control operation according to the adjusted response parameters. Otherwise, it is determined that the energy storage system cannot meet the response requirements of the current abnormal fluctuation information, and other devices or other regulation means of the power grid are required to perform fluctuation regulation or abnormal response.

[0070] In the embodiment of the present invention, by improving the existing transient overload response method, the fixed capacity configuration method and the passive dynamic adjustment method of the existing energy storage system are improved into an active dynamic adjustment method to make full use of the remaining response capabilities of the existing lithium battery system and supercapacitor system, provide a stronger transient overload response ability, and thus be able to provide a stronger stable support for the power grid and meet the actual needs of enterprises.

[0071] In the embodiment of the present invention, generating pre-overload information corresponding to the abnormal fluctuation period based on the abnormal fluctuation frequency and the abnormal fluctuation power includes: when the limit response power and the limit response time meet the response requirements: obtaining the current first capacity of the lithium battery system and the current second capacity of the supercapacitor system; pre-adjusting the first capacity and the second capacity based on the abnormal fluctuation frequency, the abnormal fluctuation power and the abnormal fluctuation period to generate corresponding pre-adjusted first capacity and pre-adjusted second capacity; generating corresponding pre-overload information based on the pre-adjusted first capacity and the pre-adjusted second capacity; when the limit response power and the limit response time do not meet the response requirements: pre-adjusting the first capacity and the second capacity based on the critical response interval, the abnormal fluctuation frequency, the abnormal fluctuation power and the abnormal fluctuation period to generate corresponding pre-adjusted third capacity and pre-adjusted fourth capacity; generating corresponding pre-overload information based on the pre-adjusted third capacity and the pre-adjusted fourth capacity.

[0072] In one possible implementation, after determining that the energy storage system has the corresponding overload response capability, in order to further reduce the impact of grid fluctuations and achieve a more intelligent control effect, pre-overload information corresponding to the abnormal fluctuation period is generated based on the abnormal fluctuation frequency and abnormal fluctuation power. Specifically, if the energy storage system can meet the above-mentioned overload response capability without the need to perform ultra-limit configuration of the energy storage system, the first capacity of the current lithium battery system and the second capacity of the supercapacitor system are directly obtained, and the first capacity and the second capacity are pre-adjusted according to the abnormal fluctuation frequency, abnormal fluctuation power and abnormal fluctuation period, and the lithium battery system is controlled to be pre-configured according to the adjusted first capacity, and the super constant capacity system is controlled to be pre-configured according to the adjusted second capacity, so that when grid fluctuations occur, the corresponding transient overload operation can be immediately executed while ensuring the normal use of the energy storage system.

[0073] In the second embodiment, if the limit response power and the limit response time do not meet the response requirements, that is, the lithium battery system and the supercapacitor system need to be over-configured for a short time to ensure sufficient transient overload response, then the first capacity and the second capacity are immediately pre-adjusted according to the critical response interval, abnormal fluctuation frequency, abnormal fluctuation power and abnormal fluctuation period, and the lithium battery system and the supercapacitor system are respectively controlled to perform corresponding pre-adjustment operations according to the pre-adjusted third capacity and the pre-adjusted fourth capacity, so as to retain only the minimum normal response to the reverse fluctuation of the power grid in a short time, so as to ensure that when the corresponding power grid fluctuation occurs, a stronger transient overload response capability can be provided to ensure the stability of the power grid.

[0074] In an embodiment of the present invention, by improving the existing energy storage system control method, on the one hand, historical load data of the power grid is used to predict its fluctuations and pre-overload configuration is performed in advance, thereby effectively improving the response speed and response capability of transient overloads. On the other hand, the instantaneous and short-term characteristics of power grid fluctuations are fully utilized. In the short period of time when power grid fluctuations are predicted to be possible, the energy storage system is controlled to retain only the minimum configuration for reverse power grid fluctuations, thereby further improving the transient overload capability. For example, if power consumption fluctuations are predicted to occur in the power grid, only the minimum configuration for charging fluctuations is retained, and the energy storage system's configuration for power consumption fluctuations is increased to the highest critical value to further improve the transient overload capability of power consumption fluctuations. This improves the transient overload capability without adding additional configuration, thereby meeting the actual needs of enterprises.

[0075] In an embodiment of the present invention, the control method further includes: after performing the transient overload operation, determining whether the abnormal fluctuation of the current power grid has ended; in the case where the abnormal fluctuation of the current power grid has ended, obtaining a first normal capacity of the lithium battery system and a second normal capacity of the supercapacitor system; controlling the lithium battery system to perform a corresponding capacity recovery operation based on the first normal capacity, and controlling the supercapacitor system to perform a corresponding capacity recovery operation based on the second normal capacity.

[0076] In a possible implementation manner, after performing pre-overload configuration on the energy storage system and executing the corresponding transient overload operation, since the energy storage system is extremely configured, in order to avoid that the normal fluctuations of the power grid cannot be timely responded to, it is also necessary to monitor in real time whether the abnormal fluctuations of the current power grid have ended. For example, in the first embodiment, although it is predicted that there will be power grid fluctuations during the current period, but actually they do not occur, and the energy storage system is still controlled to be configured according to the pre-overload information until the end of the current period, then it is determined that the abnormal fluctuations of the current power grid have ended; in the second embodiment, the fluctuations of the power grid in the current period only last for half of the time and then end. At this time, the energy storage system is still controlled to maintain the corresponding configuration according to the pre-overload information until the end of the current period, and it is determined that the abnormal fluctuations of the current power grid have ended.

[0077] At this time, obtain the first normal capacity of the lithium battery system and the second normal capacity of the supercapacitor system, and control the lithium battery system and the supercapacitor system to respectively recover to the corresponding normal capacities. For example, the capacity of the lithium battery system is recovered to 45%, and the capacity of the supercapacitor is recovered to 55%, so as to ensure the normal response to the normal fluctuations of the power grid, avoid the situation that the long-term extreme configuration cannot respond to the normal fluctuations of the power grid, and ensure the stability of the power grid power consumption.

[0078] In an embodiment of the present invention, by improving the existing energy storage system configured for the power grid, on the one hand, a voltage conversion circuit is added to the lithium battery system to appropriately improve the transient overload capacity of the lithium battery system; on the other hand, it cooperates with the supercapacitor system to further improve the transient overload capacity. At the same time, combined with the control method of the improved energy storage system, using the instantaneous and short-time characteristics of the power grid fluctuations, the energy storage system is extremely configured within the corresponding short time to further improve the transient overload capacity of the energy storage system, effectively meeting the actual needs of enterprises and improving the stability of the power grid.

[0079] The above has described in detail the optional implementation manners of the embodiments of the present invention in conjunction with the drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation manners. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.

[0080] In addition, it should be noted that, among the various specific technical features described in the above specific embodiments, they can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not separately describe various possible combination manners.

[0081] Those skilled in the art can understand that all or part of the steps in the methods of the above embodiments can be completed by instructing relevant hardware through a program. The program is stored in a storage medium, including several instructions for causing a single-chip microcomputer, a chip or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: various media such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disc that can store program codes.

[0082] In addition, any combination can be made among various different embodiments of the embodiments of the present invention, as long as it does not violate the idea of the embodiments of the present invention, and it should also be regarded as the content disclosed in the embodiments of the present invention.

Claims

1. A configuration method for an energy storage system with high transient overload capacity, characterized in that, The method includes: Obtaining the load information of the current power grid; Determining the expected overload capacity and the first configuration of the lithium battery system based on the load information; Determining the circuit parameters of the voltage conversion circuit based on the expected overload capacity and the first configuration; Determining the second configuration of the supercapacitor system based on the expected overload capacity, the first configuration, and the circuit parameters; Generating a configuration result of the energy storage system based on the first configuration, the circuit parameters, and the second configuration; The voltage conversion circuit includes a bidirectional DC / DC and a three-phase inverter. Determining the circuit parameters of the voltage conversion circuit based on the expected overload capacity and the first configuration includes: Determining the first limit overload power and the first overload time of the lithium battery system based on the first configuration; Matching the expected overload capacity based on the first limit overload power and the first overload time to generate a matching result; Determining the first configuration parameters of the bidirectional DC / DC and the second configuration parameters of the three-phase inverter based on the matching result; Generating the circuit parameters of the voltage conversion circuit based on the first configuration parameters and the second configuration parameters; The method further includes: Determining the total costs of the lithium battery system and the supercapacitor system based on the first configuration and the second configuration; Determining the expected cost; Determining a first configuration interval corresponding to the first configuration and a second configuration interval corresponding to the second configuration based on the expected cost and the total costs; Analyzing the first configuration interval and the second configuration interval based on the gradient descent algorithm to generate an optimized first configuration and an optimized second configuration; Generating a configuration result of the energy storage system based on the optimized first configuration, the circuit parameters, and the optimized second configuration.

2. The method according to claim 1, wherein Determining the expected overload capacity based on the load information includes: Performing extreme data extraction on the load information to obtain extreme load data; Performing routine analysis on the extreme load data to obtain conventional extreme load data; Performing feature extraction on the conventional extreme load data to obtain extreme load features; Determining the expected extreme power and the expected extreme response time based on the extreme load features; Generating the expected overload capacity based on the expected extreme power and the expected extreme response time.

3. The method according to claim 2, wherein Determining the second configuration of the supercapacitor system based on the expected overload capacity, the first configuration, and the circuit parameters includes: Determining the overload power deviation and the overload time deviation of the lithium battery system based on the expected overload capacity, the first configuration, and the circuit parameters; Determining the second limit overload power and the second overload time based on the overload power deviation and the overload time deviation; Determining the second configuration of the supercapacitor system based on the second limit overload power and the second overload time.

4. A control method for an energy storage system, characterized in that, The control method is applied to an energy storage system with high transient overload capacity. The control method includes: Obtaining the historical load information of the current power grid; Determining the abnormal fluctuation information of the current power grid based on the historical load information. The abnormal fluctuation information includes abnormal fluctuation frequency, abnormal fluctuation power, and abnormal fluctuation time; Judge whether the energy storage system has corresponding overload response capability based on the abnormal fluctuation information; If so, generate pre-overload information corresponding to the abnormal fluctuation period based on the abnormal fluctuation frequency and the abnormal fluctuation power; Control the energy storage system to perform corresponding transient overload operations based on the pre-overload information; The judging whether the energy storage system has corresponding overload response capability based on the abnormal fluctuation information includes: Obtain the limit response parameters of the energy storage system, where the limit response parameters include the limit response power and the corresponding limit response time; Judge whether the limit response power and the limit response time meet the response requirements of the abnormal fluctuation information; If the limit response power and the limit response time meet the response requirements, determine that the energy storage system has overload response capability; Otherwise: Determine the critical response interval, and adjust the limit response parameters based on the critical response interval to generate adjusted response parameters; Judge whether the adjusted response parameters meet the response requirements of the abnormal fluctuation information; If the adjusted response parameters meet the response requirements, determine that the energy storage system has overload response capability; If the adjusted response parameters do not meet the response requirements, determine that the energy storage system does not have overload response capability; The energy storage system includes a lithium battery system and a supercapacitor system, and the determining the critical response interval includes: Obtain the first power configuration and the first response time of the lithium battery system, and obtain the second power configuration and the second response time of the supercapacitor system; Determine the fluctuation type based on the abnormal fluctuation information, and obtain the average charging power of the current power grid; Determine the first safety power threshold corresponding to the lithium battery system and the fluctuation type, and the second safety power threshold corresponding to the supercapacitor system and the fluctuation type; Determine the second overlimit configuration of the supercapacitor system based on the second power configuration, the average charging power, the second safety power threshold and the second response time; Determine the first overlimit configuration of the lithium battery system based on the second overlimit configuration, the first power configuration, the average charging power, the first safety power threshold and the first response time; Cooperatively optimize the first overlimit configuration and the second overlimit configuration based on the first temperature rise curve of the lithium battery system and the second temperature rise curve of the supercapacitor system to generate corresponding first optimized configuration and second optimized configuration; Determine the critical response interval based on the first optimized configuration and the second optimized configuration.

5. The control method according to claim 4, wherein The generating pre-overload information corresponding to the abnormal fluctuation period based on the abnormal fluctuation frequency and the abnormal fluctuation power includes: In the case where the limit response power and the limit response time meet the response requirements: Obtain the current first capacity of the lithium battery system and the current second capacity of the supercapacitor system; Pre-adjust the first capacity and the second capacity based on the abnormal fluctuation frequency, the abnormal fluctuation power and the abnormal fluctuation period to generate corresponding pre-adjusted first capacity and pre-adjusted second capacity; Generate corresponding pre-overload information based on the pre-adjusted first capacity and the pre-adjusted second capacity; In the case where the limit response power and the limit response time do not meet the response requirements: Pre-adjust the first capacity and the second capacity based on the critical response interval, the abnormal fluctuation frequency, the abnormal fluctuation power, and the abnormal fluctuation period to generate corresponding pre-adjusted third capacity and pre-adjusted fourth capacity; Generate corresponding pre-overload information based on the pre-adjusted third capacity and the pre-adjusted fourth capacity.

6. The control method according to claim 4, wherein The control method further includes: After performing the transient overload operation, determine whether the abnormal fluctuation of the current power grid has ended; When the abnormal fluctuation of the current power grid ends, obtain the first conventional capacity of the lithium battery system and the second conventional capacity of the supercapacitor system; Control the lithium battery system to perform a corresponding capacity recovery operation based on the first conventional capacity, and control the supercapacitor system to perform a corresponding capacity recovery operation based on the second conventional capacity.

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