Capacity configuration method and device of energy storage system

Abstract

The invention provides a capacity configuration method and device of an energy storage system, and relates to the technical field of energy storage configuration. The method comprises the following steps: acquiring the maximum amplitude of a power angle of the energy storage system during a fault period, and acquiring the minimum inertia of the system if the maximum amplitude of the power angle is determined to be greater than a preset maximum amplitude threshold value of the power angle; according to the minimum inertia of the system, obtaining the equivalent inertia which needs to be provided by the energy storage system meeting the maximum amplitude constraint of the power angle, and determining the total configuration capacity, determined by the maximum amplitude of the power angle, of the energy storage system according to the equivalent inertia; if it is determined that the total configuration capacity is larger than all static energy of the supercapacitor, the lithium battery configuration capacity meeting the maximum amplitude constraint of the power angle is determined. According to the method and the device provided by the embodiment of the invention, the economical efficiency and the reliability of the energy storage system can be ensured.

Description

Technical Field

[0001] This invention relates to the field of energy storage configuration technology, and specifically to a capacity configuration method and apparatus for an energy storage system. Background Technology

[0002] With the continuous expansion of installed capacity of new energy sources such as wind power and photovoltaics, the inertial support capacity of power systems is showing a continuous downward trend. The transient stability characteristics traditionally maintained by the rotor inertia of synchronous generators are significantly weakened under conditions of high-proportion power electronics. When the system suffers short-circuit faults, power surges, or unit disconnection, the power angle deviation in the electromechanical transient process intensifies and the rate of change increases, resulting in a significant reduction in the system's synchronous stability margin. To suppress the rapid energy imbalance caused by such disturbances, external energy storage devices (i.e., energy storage systems) are gradually becoming an important component for enhancing power system stability.

[0003] External energy storage devices are widely used to provide additional "transient support" due to their rapid energy exchange capabilities. Supercapacitors, with their fast response speed and high power density, are better suited for suppressing rapid power angle shifts in the initial stages of disturbances; while lithium batteries, with their high energy density, can handle energy compensation in the mid-to-late stages, making them an effective way to construct a hybrid energy storage support system. Therefore, how to rationally plan the capacity and timing of these two types of energy storage based on the system's disturbance characteristics is a crucial technical issue for ensuring transient stability.

[0004] However, existing energy storage configuration studies mostly focus on overall operational performance or energy economy, determining capacity configuration through optimization strategies, equivalent models, or empirical parameters, primarily addressing steady-state and quasi-steady-state indicators. While such methods can balance cost and lifespan, they generally lack constrained modeling of power angle dynamics during electromechanical transients, making it difficult to quantify the minimum energy storage requirement from the power angle safety boundary. Especially under strong disturbances, relying solely on energy balance or global indicators is insufficient to reflect the relative dynamic behavior between units, potentially leading to energy storage capacity redundancy or insufficient support. Summary of the Invention

[0005] To address the problems in the prior art, embodiments of the present invention provide a capacity configuration method and apparatus for an energy storage system, which can at least partially solve the problems existing in the prior art.

[0006] On one hand, this invention proposes a capacity configuration method for an energy storage system, comprising: Obtain the maximum amplitude of the power angle of the energy storage system during the fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, then obtain the minimum inertia of the system. The equivalent inertia required by the energy storage system to satisfy the maximum amplitude constraint of the power angle is obtained based on the minimum inertia of the system, and the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle is determined based on the equivalent inertia. If the total capacity of the configuration is determined to be greater than the total static energy of the supercapacitor, then the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle is determined.

[0007] The method of obtaining the maximum amplitude of the power angle of the energy storage system during a fault includes: The maximum speed deviation of the energy storage system is determined based on a pre-established speed response model; The maximum amplitude of the power angle is calculated based on the pre-established power angle-speed mapping relationship.

[0008] The step of determining the maximum speed deviation of the energy storage system based on a pre-established speed response model includes: Determine the extreme value time of the speed response of the energy storage system based on the speed response model; Substituting the extreme time of the speed response into the speed response model, the maximum speed deviation is calculated.

[0009] The process of obtaining the minimum inertia of the system includes: Using the preset maximum amplitude threshold of the power angle and the disturbance power as independent variables, the minimum inertia of the system is obtained by inversely solving the power angle-speed mapping relationship.

[0010] The determination of the total configuration capacity of the energy storage system, which is determined by the maximum amplitude of the power angle, based on the equivalent inertia includes: The discharge capacity or charging capacity in the total configuration capacity of the energy storage system is determined based on the sign of the maximum amplitude of the power angle.

[0011] The determination of the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle includes: If the total capacity is determined to be the discharge capacity, the discharge capacity is calculated based on the available capacity that the lithium battery needs to reserve, the initial SOC of the lithium battery, and the minimum SOC of the lithium battery. If the total configuration capacity is determined to be the charging capacity, then the charging capacity is calculated based on the reservable absorption capacity of the lithium battery, the initial SOC of the lithium battery, and the maximum SOC of the lithium battery.

[0012] On one hand, the present invention proposes a capacity configuration device for an energy storage system, comprising: The acquisition unit is used to acquire the maximum amplitude of the power angle of the energy storage system during a fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, the minimum inertia of the system is acquired. The determination unit is used to obtain the equivalent inertia that the energy storage system needs to provide to meet the maximum amplitude constraint of the power angle based on the minimum inertia of the system, and to determine the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle based on the equivalent inertia. The configuration unit is used to determine the lithium battery configuration capacity that satisfies the maximum power angle constraint if the total configuration capacity is determined to be greater than the total static energy possessed by the supercapacitor.

[0013] In another aspect, embodiments of the present invention provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the following method: Obtain the maximum amplitude of the power angle of the energy storage system during the fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, then obtain the minimum inertia of the system. The equivalent inertia required by the energy storage system to satisfy the maximum amplitude constraint of the power angle is obtained based on the minimum inertia of the system, and the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle is determined based on the equivalent inertia. If the total capacity of the configuration is determined to be greater than the total static energy of the supercapacitor, then the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle is determined.

[0014] This invention provides a computer-readable storage medium, comprising: The computer-readable storage medium stores a computer program that, when executed by a processor, implements the following method: Obtain the maximum amplitude of the power angle of the energy storage system during the fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, then obtain the minimum inertia of the system. The equivalent inertia required by the energy storage system to satisfy the maximum amplitude constraint of the power angle is obtained based on the minimum inertia of the system, and the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle is determined based on the equivalent inertia. If the total capacity of the configuration is determined to be greater than the total static energy of the supercapacitor, then the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle is determined.

[0015] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the following method: Obtain the maximum amplitude of the power angle of the energy storage system during the fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, then obtain the minimum inertia of the system. The equivalent inertia required by the energy storage system to satisfy the maximum amplitude constraint of the power angle is obtained based on the minimum inertia of the system, and the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle is determined based on the equivalent inertia. If the total capacity of the configuration is determined to be greater than the total static energy of the supercapacitor, then the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle is determined.

[0016] The capacity configuration method and apparatus for an energy storage system provided in this invention obtain the maximum power angle amplitude of the energy storage system during a fault. If the maximum power angle amplitude is determined to be greater than a preset maximum power angle amplitude threshold, the minimum inertia of the system is obtained. Based on the minimum system inertia, the equivalent inertia that the energy storage system needs to provide to satisfy the maximum power angle amplitude constraint is obtained, and the total configuration capacity of the energy storage system determined by the maximum power angle amplitude is determined based on the equivalent inertia. If the total configuration capacity is determined to be greater than the total static energy possessed by the supercapacitor, the configuration capacity of the lithium battery that satisfies the maximum power angle amplitude constraint is determined. By introducing the maximum power angle amplitude constraint, the direct coupling between energy storage capacity and system stability is achieved, thereby ensuring the economy and reliability of the energy storage system. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a flowchart illustrating a capacity configuration method for an energy storage system provided in an embodiment of the present invention.

[0018] Figure 2 This is a flowchart illustrating a capacity configuration method for an energy storage system provided in another embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the capacity configuration device of an energy storage system provided in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the physical structure of a computer device provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0022] This invention aims to propose a dynamic energy storage capacity matching method with the maximum amplitude of the power angle as the core constraint: establishing a mapping relationship between the maximum amplitude of the power angle and the transient response process dominated by system inertia; calculating the limit cut-off angle and the limit cut-off time using the equal area method; quantitatively mapping the power angle constraint to the minimum inertia requirement of the system and thereby inferring the power and capacity requirements of the energy storage system; based on this, this invention proposes a phased hybrid energy storage capacity allocation strategy (supercapacitor priority, lithium battery supplementation), thereby achieving both economic efficiency and reliability of energy storage configuration while ensuring transient synchronization stability.

[0023] This invention addresses the capacity mismatch problem caused by reliance on experience or overall energy indicators in existing energy storage configuration methods. It uses the maximum amplitude of the power angle as a constraint to construct a quantitative mapping from the power angle constraint to the equivalent transient energy demand, and then uses this mapping to inversely deduce the power and capacity requirements of energy storage. This method uses the maximum amplitude of the power angle as an engineering indicator highly correlated with transient stability as a more physical and targeted input for energy storage configuration, thereby achieving more accurate and economical capacity configuration and allocation.

[0024] When a power system is subjected to disturbances, the dynamic change in the power angle directly reflects the energy exchange process between the mechanical input and electromagnetic output of the synchronous generator unit, and is a core state variable for measuring transient stability. When the power angle deviation exceeds the critical range, the unit may lose synchronization, leading to stability failure. Therefore, suppressing the maximum amplitude of the power angle is crucial to ensuring the safe operation of the system. Existing energy storage configurations and inertia regulation methods mostly rely on the overall energy change characteristics of the system as constraints, making it difficult to characterize the relative dynamic relationships between units. The results often fail to accurately reflect the synchronization characteristics during transient periods. In contrast, the power angle amplitude more directly reflects the impact of disturbances on electromagnetic coupling, and its variation range can be used to define the transient stability boundary.

[0025] Based on this, this invention proposes using the maximum amplitude of the power angle as the core constraint index for energy storage capacity configuration and inertia adjustment. By establishing a mapping relationship between the maximum amplitude of the power angle and the maximum deviation of the rotational speed, the minimum inertia requirement of the system is deduced from the power angle level, achieving an innovative method for obtaining precise energy storage capacity configuration from the "power angle constraint". This approach not only more accurately characterizes the transient response characteristics of the system, but also directly reflects the impact of factors such as fault clearing time and disturbance intensity on the system stability margin, providing a more physically meaningful configuration basis for energy storage systems.

[0026] Figure 1 This is a flowchart illustrating a capacity configuration method for an energy storage system according to an embodiment of the present invention, as shown below. Figure 1 As shown, the capacity configuration method for an energy storage system provided in this embodiment of the invention includes: Step S1: Obtain the maximum amplitude of the power angle of the energy storage system during the fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, then obtain the minimum inertia of the system.

[0027] Step S2: Obtain the equivalent inertia required by the energy storage system to satisfy the maximum amplitude constraint of the power angle based on the minimum inertia of the system, and determine the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle based on the equivalent inertia.

[0028] Step S3: If it is determined that the total configuration capacity is greater than the total static energy of the supercapacitor, then determine the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle.

[0029] In step S1 above, the device acquires the maximum power angle amplitude of the energy storage system during a fault. If the maximum power angle amplitude is determined to be greater than a preset maximum power angle amplitude threshold, the minimum inertia of the system is acquired. The device can be a computer device that executes this method. The acquisition, storage, use, and processing of data in the technical solution of this application all comply with relevant regulations. Acquiring the maximum power angle amplitude of the energy storage system during a fault includes: The maximum speed deviation of the energy storage system is determined based on a pre-established speed response model; The maximum amplitude of the power angle is calculated based on the pre-established power angle-speed mapping relationship.

[0030] The determination of the maximum speed deviation of the energy storage system based on the pre-established speed response model includes: Determine the extreme value time of the speed response of the energy storage system based on the speed response model; Substituting the extreme time of the speed response into the speed response model, the maximum speed deviation is calculated.

[0031] The method for obtaining the maximum amplitude of the power angle is explained below: Since the time interval from the occurrence of the fault to the disconnection of the faulty line is extremely short, the angular velocity during this time interval can be approximated as constant. Therefore, the maximum amplitude change of the power angle mainly depends on the maximum deviation of the rotational speed, and its expression is as follows: (1) Among them, t cr For the fault clearing time of the energy storage system, This represents the maximum deviation in rotational speed.

[0032] During normal system operation, the generator power angle is at a stable equilibrium point. After a fault occurs, due to the decrease in electromagnetic power, the generator enters an "acceleration" process, and the power angle continuously increases. When the fault is cleared, the electromagnetic power recovers, and the generator enters a "deceleration" process, gradually suppressing the upward trend of the power angle. If the fault is cleared in time, the acceleration energy gained by the unit during the fault period and the deceleration energy released by the unit after the fault are offset, and the power angle can return to a new stable equilibrium point. The power angle corresponding to the clearing moment at this time is the limiting clearing angle. Conversely, if the fault is cleared too late and the unit's acceleration energy is too great, it cannot be offset by the subsequent deceleration phase, and the system will become unstable.

[0033] Obtaining the ultimate resection angle Then, it is necessary to further calculate the corresponding limit resection time t. cr To achieve this transformation, the second-order differential equation of the generator rotor dynamic characteristics can be solved to obtain... The time trajectory expression. Based on this trajectory, the power angle changes from the pre-fault stable point. Evolved to the limit resection angle The moment when the energy balance condition is met during the process is the limiting resection time t. cr Its mathematical expression is as follows: (2) in, C1 is the angular velocity of the synchronous machine; C1 is the integral constant determined by the initial conditions; H is the generator inertia constant. This is the stable point before the failure; The electromagnetic power curve during the fault period is shown; Pm is the mechanical input power.

[0034] To evaluate the maximum speed deviation of the system, this invention constructs a speed response model to describe this dynamic process, the mathematical expression of which is as follows: (3) in, (4) Where Hs is the system inertia; T G Ks is the time constant for the reheat process; Ks is the primary frequency regulation coefficient of the system under the new energy penetration rate. This represents the disturbance power experienced by the system.

[0035] Taking the derivative of equation (3), the moment when the derivative is 0 is the moment of the maximum response extremum of the rotational speed deviation. The extreme time t of the rotational speed response of the energy storage system can be calculated from this. h as follows: (5) Substituting the extreme time of the speed response obtained from equation (5) into the speed response model, the maximum speed deviation of the system can be determined, and it can be converted into the maximum amplitude of the power angle through the mapping relationship. It can be expressed by the following formula: (6) The process of obtaining the minimum inertia of the system includes: Using the preset maximum amplitude threshold of the power angle and the disturbance power as independent variables, the minimum inertia of the system is obtained by inversely solving the power angle-speed mapping relationship.

[0036] Even under abnormal conditions, the maximum amplitude of the power angle in a power system should remain within the required operating range. As shown in equation (6), the maximum amplitude of the power angle... With disturbance power It is closely related to many parameters such as synchronous machine parameters, new energy penetration rate, and system inertia Hs, especially the core parameters describing the transient response characteristics of the power angle (including... Both M and Hs have embedded system inertia Hs, which makes a clear quantitative correspondence between the maximum amplitude of the power angle and Hs.

[0037] When the system faces disturbance power When determining this, if a safety constraint threshold for the maximum amplitude of the power angle is given in advance. (With a preset maximum amplitude threshold for the power angle), the minimum inertia Hsmin of the system that satisfies this constraint can be solved in reverse by equation (6). In other words, the minimum inertia requirement of the system can be directly derived from the safety constraint of the maximum amplitude of the power angle, as shown in the following equation: (7) like Figure 2 As shown, if the maximum amplitude of the power angle is determined to be less than or equal to the preset maximum amplitude threshold, the following can be executed: Figure 2 The relevant steps are shown below.

[0038] In step S2 above, the device obtains the equivalent inertia required by the energy storage system to satisfy the maximum power angle amplitude constraint based on the system's minimum inertia, and determines the total configuration capacity of the energy storage system determined by the maximum power angle amplitude based on the equivalent inertia. When the maximum power angle amplitude of the system does not meet the safety index, an energy storage system needs to be configured and its inertia control needs to be added. By increasing the equivalent inertia to compensate for the inertia gap, the variation of the system's maximum power angle is constrained within the safe range. The corresponding minimum inertia requirement expression can be expressed by the following formula: (8) Among them, H g p represents the synchronous machine inertia; p represents the penetration rate of new energy sources. This is the equivalent inertia.

[0039] According to equation (8), the inertia H of the synchronizer in the system is known. g By calculating the new energy penetration rate p, we can obtain the energy storage system's required output to the system. It can be expressed by the following formula: (9) After a system disturbance, the power angle shifts from the steady-state equilibrium point and gradually reaches its maximum amplitude. This evolution corresponds to the change in rotational speed deviation. Therefore, the transient response process of the power angle amplitude can be mapped to an equivalent rotational speed response process. The time interval from the moment of disturbance to the point where the rotational speed reaches its extreme value can be considered the dominant stage of the power angle amplitude change. This stage reflects the duration for which the energy storage system needs to provide rapid inertial support. Based on the power demand and equivalent response duration derived from the power angle constraint, the total capacity required for the energy storage system can be calculated as follows: (10) in, S is the inertial capacity safety factor of the energy storage system. base The reference power is selected as the system rated capacity, and the unit is MW.

[0040] The determination of the total configuration capacity of the energy storage system based on the equivalent inertia, which is determined by the maximum amplitude of the power angle, includes: The discharge capacity or charging capacity in the total configuration capacity of the energy storage system is determined based on the sign of the maximum amplitude of the power angle.

[0041] As can be seen from equation (10), the total capacity of the energy storage system depends on the maximum amplitude of the system's power angle. It is worth noting that, The sign of the energy storage system changes depending on the intensity of the disturbance or the type of fault. This means that the system must not only provide energy to cope with positive amplitude operating conditions, but also absorb energy to cope with negative amplitude operating conditions, thus constituting its unique bidirectional power demand. Therefore, the capacity demand is also divided into two parts: discharge capacity and charging capacity, expressed by the following formula: (11) Among these measures, to reserve redundancy margins for the energy storage system capacity, the following is introduced: As a capacity safety factor, its typical value range is 1.05 to 1.1. Discharge capacity; This refers to the charging capacity.

[0042] In step S3 above, if the device determines that the total configured capacity is greater than the total static energy possessed by the supercapacitor, then it determines the lithium battery configuration capacity that satisfies the maximum power angle amplitude constraint. If the total configured capacity is determined to be less than or equal to the total static energy possessed by the supercapacitor... The situation is as follows Figure 2 The relevant steps are shown below.

[0043] In hybrid energy storage systems, to simplify control logic and improve response speed, this invention sets the capacity of the supercapacitor to a known fixed value. When a disturbance occurs in the system, the supercapacitor first rapidly releases energy to suppress abrupt changes in the power angle amplitude and provide instantaneous power support. The supercapacitor handles the entire inertial response process until its energy is fully released or the system fault is cleared. If the fault is cleared before the supercapacitor has finished discharging, the energy release from the supercapacitor is sufficient to meet the system stability requirements, and the lithium battery is not required. If the fault is not cleared in time, causing the supercapacitor to run out of energy, the lithium battery must intervene to provide continuous power support to compensate for the energy gap and maintain system power angle stability. Thus, the need for lithium battery capacity can be determined based on the supercapacitor's discharge state, thereby achieving graded capacity matching and coordinated response of the energy storage system.

[0044] The usable energy of a lithium battery is related to its state of charge (SOC). To describe the remaining usable energy of a battery, the SOC of a lithium battery can be defined as g. SOC It can be expressed as follows: (12) Among them, Q B and i B These represent the lithium battery's charge capacity and output current, respectively.

[0045] The static energy that a lithium battery can release at a certain moment can be regarded as the product of the terminal voltage and the available charge, which can be further expressed by the following formula: (13) Among them, u B The output voltage of the lithium battery; g SOC-0 This represents the initial state of charge (SOC) of the lithium battery.

[0046] Supercapacitors also possess significant static energy storage capacity, with their energy determined by both the terminal voltage and the equivalent capacitance. Correspondingly, the state of charge of a supercapacitor is denoted as... It can be expressed by the following formula: (14) Among them, Q C and u C These represent the charge and output voltage of the supercapacitor, respectively; C is its equivalent capacitance.

[0047] Similarly, the total static energy possessed by a supercapacitor can be expressed by the following formula: (15) in, This represents the initial state of charge (SOC) of the supercapacitor.

[0048] Because the initial state of charge (SOC) of supercapacitors varies, and energy release and absorption are constrained by upper and lower limits of SOC, the actual energy that can be released and absorbed will also change accordingly. Therefore, the total energy that a supercapacitor can absorb can be expressed by the following formula: (16) in, This is the initial operating voltage of the supercapacitor; This refers to the maximum permissible voltage of the supercapacitor. The maximum allowable SOC for a supercapacitor.

[0049] The total energy that a supercapacitor can release can be expressed as: (17) in, This is the minimum permissible voltage for a supercapacitor; This is the minimum allowable SOC value for a supercapacitor.

[0050] When the load suddenly increases, the supercapacitor preferentially releases energy to provide power support. This process continues until the fault is completely cleared or its releaseable energy is completely exhausted. If the fault is not eliminated when the supercapacitor has finished discharging, the lithium battery needs to intervene in time to supplement power, thereby ensuring that the system smoothly passes through the fault phase. Therefore, the available capacity that the lithium battery needs to reserve should satisfy the following formula: (18) Considering the initial SOC of the lithium battery is g SOC-0 The total capacity required can be expressed by the following formula (i.e., discharge capacity): (19) When the load drops sharply, the supercapacitor preferentially absorbs excess energy to smooth power fluctuations. This process continues until the operating conditions stabilize or its absorbable energy reaches the upper limit of its State of Charge (SOC). If the operating conditions are still not stable when the supercapacitor is saturated, the lithium battery needs to intervene promptly to absorb the remaining energy to ensure the safe operation of the system. Therefore, the available absorption capacity that the lithium battery needs to reserve should satisfy the following formula: (20) Considering the initial SOC of the lithium battery is g SOC-0 The total capacity required for its configuration can be expressed by the following formula (i.e., charging capacity): (twenty one) Given the known supercapacitor capacity E Cand the capacity E of the lithium battery B Then, the transient energy equivalent time constant H of the supercapacitor can be obtained by reversing the energy storage element's capacity using equation (12). C Equivalent time constant H of transient energy of lithium battery B Its formula can be expressed by the following formula: (twenty two) Based on this, the time-domain power distribution between the supercapacitor and the lithium battery in the hybrid energy storage system can be realized according to the transient energy response control equation in the form of the second derivative of the power angle, ensuring that the energy storage output is coordinated with the dynamic process of the power angle, which can be expressed as follows: (twenty three) Among them, P C (t) and P B (t) represents the output power of the supercapacitor and the lithium battery, respectively.

[0051] This invention proposes and implements a hybrid energy storage capacity and power integrated configuration and control method centered on the maximum power angle amplitude constraint. This method forms a closed-loop mapping link from the power angle constraint to the energy storage capacity and power output, realizing direct coupling between energy storage system parameter configuration and system transient stability indicators. Through a theoretical approach dominated by the maximum power angle amplitude constraint, this invention can achieve optimal allocation of energy storage system capacity and coordinated power control while ensuring that the maximum power angle amplitude meets safety indicators, balancing system stability, economy, and feasibility. This provides a new technical approach for the dynamic stability support of high-proportion renewable energy power systems.

[0052] The capacity configuration method for energy storage systems provided in this invention has the following beneficial technical effects: 1. More accurate transient stability constraints: Using the maximum amplitude of the power angle as the configuration constraint can directly reflect the relative dynamic characteristics and transient synchronization margin between units, overcoming the problem of insufficient characterization of unit synchronization under the traditional capacity configuration method, and improving the pertinence and effectiveness of energy storage configuration from the physical level.

[0053] 2. Reduce energy storage configuration and improve economic efficiency: By inversely deriving the minimum inertia required by the system through the maximum power angle amplitude constraint, the minimum capacity configuration requirement of the energy storage system can be accurately calculated, avoiding the phenomenon of over-configuration of energy storage, thereby reducing the overall energy storage capacity investment and operating costs.

[0054] 3. Adapting to high-penetration new energy scenarios and improving the stability of new power systems: The capacity configuration method considers parameters such as the new energy penetration rate p and the primary frequency regulation coefficient Ks, and uses the maximum power angle amplitude constraint as the core to configure the energy storage system capacity. It takes into account the impact of high new energy penetration on system inertia and transient characteristics, and is suitable for modern power grids with high wind power / high photovoltaic penetration.

[0055] 4. Improve system transient response speed and stability: The present invention adopts a hybrid energy storage system, in which the supercapacitor provides instantaneous inertia support first, with short response time and high power density; the lithium battery supplements energy for continuous support. The synergy of the two can shorten the system recovery time and improve fault robustness while ensuring that the power angle amplitude is controlled.

[0056] The capacity configuration method for an energy storage system provided in this embodiment of the invention obtains the maximum power angle amplitude of the energy storage system during a fault. If the maximum power angle amplitude is determined to be greater than a preset maximum power angle amplitude threshold, the minimum inertia of the system is obtained. Based on the minimum system inertia, the equivalent inertia that the energy storage system needs to provide to satisfy the maximum power angle amplitude constraint is obtained, and the total configuration capacity of the energy storage system determined by the maximum power angle amplitude is determined based on the equivalent inertia. If the total configuration capacity is determined to be greater than the total static energy possessed by the supercapacitor, the configuration capacity of the lithium battery that satisfies the maximum power angle amplitude constraint is determined. By introducing the maximum power angle amplitude constraint, the direct coupling between energy storage capacity and system stability is achieved, thereby ensuring the economy and reliability of the energy storage system.

[0057] In the above optional embodiments, obtaining the maximum amplitude of the power angle of the energy storage system during a fault includes: The maximum deviation of the energy storage system's rotational speed is determined based on a pre-established rotational speed response model; this can be referred to the above embodiments for explanation, and will not be repeated here.

[0058] The maximum amplitude of the power angle is calculated based on the pre-established power angle-speed mapping relationship. This can be referred to the above embodiment for explanation, and will not be repeated here.

[0059] In the above optional embodiments, determining the maximum speed deviation of the energy storage system based on a pre-established speed response model includes: The extreme time of the speed response of the energy storage system is determined based on the speed response model; the above embodiments can be referred to for explanation, and will not be repeated here.

[0060] Substituting the extreme time of the speed response into the speed response model, the maximum speed deviation is calculated. This can be referred to the above embodiment for explanation, and will not be repeated here.

[0061] In the above optional embodiments, obtaining the minimum inertia of the system includes: Using a preset maximum amplitude threshold for the power angle and the disturbance power as independent variables, the minimum inertia of the system is obtained by inversely solving the power angle-speed mapping relationship. This can be referred to the above embodiment for further explanation, and will not be repeated here.

[0062] In the above optional embodiments, determining the total configuration capacity of the energy storage system based on the equivalent inertia, which is determined by the maximum amplitude of the power angle, includes: The discharge capacity or charging capacity in the total configuration capacity of the energy storage system is determined based on the sign of the maximum amplitude of the power angle. This can be referred to the above embodiments for explanation, and will not be repeated here.

[0063] In the above optional embodiments, determining the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle includes: If the total capacity is determined to be the discharge capacity, the discharge capacity is calculated based on the available capacity that the lithium battery needs to reserve, the initial SOC of the lithium battery, and the minimum SOC of the lithium battery; the above embodiments can be referred to for explanation, and will not be repeated here.

[0064] If the total configuration capacity is determined to be the charging capacity, then the charging capacity is calculated based on the reservable absorption capacity of the lithium battery, the initial SOC of the lithium battery, and the maximum SOC of the lithium battery. This can be referred to the above embodiments for explanation, and will not be repeated here.

[0065] Figure 3 This is a schematic diagram of the capacity configuration device of an energy storage system provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the capacity configuration device for an energy storage system provided in this embodiment of the invention includes an acquisition unit 301, a determination unit 302, and a configuration unit 303, wherein: The acquisition unit 301 is used to acquire the maximum power angle amplitude of the energy storage system during a fault. If it is determined that the maximum power angle amplitude is greater than the preset maximum power angle amplitude threshold, the minimum inertia of the system is acquired. The determination unit 302 is used to acquire the equivalent inertia that the energy storage system needs to provide to meet the maximum power angle amplitude constraint based on the minimum system inertia, and to determine the total configuration capacity of the energy storage system determined by the maximum power angle amplitude based on the equivalent inertia. The configuration unit 303 is used to determine the lithium battery configuration capacity that meets the maximum power angle amplitude constraint if it is determined that the total configuration capacity is greater than the total static energy possessed by the supercapacitor.

[0066] Specifically, the acquisition unit 301 in the device is used to acquire the maximum power angle amplitude of the energy storage system during a fault. If it is determined that the maximum power angle amplitude is greater than a preset maximum power angle amplitude threshold, the minimum inertia of the system is acquired. The determination unit 302 is used to acquire the equivalent inertia that the energy storage system needs to provide to meet the maximum power angle amplitude constraint based on the minimum system inertia, and to determine the total configuration capacity of the energy storage system determined by the maximum power angle amplitude based on the equivalent inertia. The configuration unit 303 is used to determine the lithium battery configuration capacity that meets the maximum power angle amplitude constraint if it is determined that the total configuration capacity is greater than the total static energy possessed by the supercapacitor.

[0067] The capacity configuration device for an energy storage system provided in this embodiment of the invention obtains the maximum amplitude of the power angle of the energy storage system during a fault. If the maximum amplitude of the power angle is determined to be greater than a preset maximum amplitude threshold, the minimum inertia of the system is obtained. Based on the minimum inertia of the system, the equivalent inertia that the energy storage system needs to provide to meet the maximum amplitude constraint is obtained, and the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle is determined based on the equivalent inertia. If the total configuration capacity is determined to be greater than the total static energy possessed by the supercapacitor, the configuration capacity of the lithium battery that meets the maximum amplitude constraint is determined. By introducing the maximum amplitude constraint, the direct coupling between energy storage capacity and system stability is achieved, thereby ensuring the economy and reliability of the energy storage system.

[0068] Figure 4 This is a schematic diagram of the physical structure of a computer device provided in an embodiment of the present invention, such as... Figure 4 As shown, the computer device includes: a memory 401, a processor 402, and a computer program stored in the memory 401 and executable on the processor 402. When the processor 402 executes the computer program, it implements the following method: Obtain the maximum amplitude of the power angle of the energy storage system during the fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, then obtain the minimum inertia of the system. The equivalent inertia required by the energy storage system to satisfy the maximum amplitude constraint of the power angle is obtained based on the minimum inertia of the system, and the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle is determined based on the equivalent inertia. If the total capacity of the configuration is determined to be greater than the total static energy of the supercapacitor, then the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle is determined.

[0069] This embodiment discloses a computer program product, which includes a computer program that, when executed by a processor, implements the following method: Obtain the maximum amplitude of the power angle of the energy storage system during the fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, then obtain the minimum inertia of the system. The equivalent inertia required by the energy storage system to satisfy the maximum amplitude constraint of the power angle is obtained based on the minimum inertia of the system, and the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle is determined based on the equivalent inertia. If the total capacity of the configuration is determined to be greater than the total static energy of the supercapacitor, then the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle is determined.

[0070] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the following method: Obtain the maximum amplitude of the power angle of the energy storage system during the fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, then obtain the minimum inertia of the system. The equivalent inertia required by the energy storage system to satisfy the maximum amplitude constraint of the power angle is obtained based on the minimum inertia of the system, and the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle is determined based on the equivalent inertia. If the total capacity of the configuration is determined to be greater than the total static energy of the supercapacitor, then the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle is determined.

[0071] Compared with existing technologies, the energy storage system capacity configuration method provided in this invention obtains the maximum power angle amplitude of the energy storage system during a fault. If the maximum power angle amplitude is greater than a preset maximum power angle amplitude threshold, the minimum inertia of the system is obtained. Based on the minimum system inertia, the equivalent inertia required by the energy storage system to satisfy the maximum power angle amplitude constraint is obtained, and the total configuration capacity of the energy storage system determined by the maximum power angle amplitude is determined based on the equivalent inertia. If the total configuration capacity is greater than the total static energy of the supercapacitor, the lithium battery configuration capacity that satisfies the maximum power angle amplitude constraint is determined. By introducing the maximum power angle amplitude constraint, the direct coupling between energy storage capacity and system stability is achieved, thereby ensuring the economy and reliability of the energy storage system.

[0072] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0073] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0074] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0075] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0076] In the description of this specification, the references to terms such as "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0077] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for configuring the capacity of an energy storage system, characterized in that, include: Obtain the maximum amplitude of the power angle of the energy storage system during the fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, then obtain the minimum inertia of the system. The equivalent inertia required by the energy storage system to satisfy the maximum amplitude constraint of the power angle is obtained based on the minimum inertia of the system, and the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle is determined based on the equivalent inertia. If the total capacity of the configuration is determined to be greater than the total static energy of the supercapacitor, then the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle is determined.

2. The capacity configuration method for an energy storage system according to claim 1, characterized in that, The method of obtaining the maximum amplitude of the power angle of the energy storage system during a fault includes: The maximum speed deviation of the energy storage system is determined based on a pre-established speed response model; The maximum amplitude of the power angle is calculated based on the pre-established power angle-speed mapping relationship.

3. The capacity configuration method for an energy storage system according to claim 2, characterized in that, The determination of the maximum speed deviation of the energy storage system based on the pre-established speed response model includes: Determine the extreme value time of the speed response of the energy storage system based on the speed response model; Substituting the extreme time of the speed response into the speed response model, the maximum speed deviation is calculated.

4. The capacity configuration method for an energy storage system according to claim 2, characterized in that, The process of obtaining the minimum inertia of the system includes: Using the preset maximum amplitude threshold of the power angle and the disturbance power as independent variables, the minimum inertia of the system is obtained by inversely solving the power angle-speed mapping relationship.

5. The capacity configuration method for an energy storage system according to claim 1, characterized in that, The determination of the total configuration capacity of the energy storage system based on the equivalent inertia, which is determined by the maximum amplitude of the power angle, includes: The discharge capacity or charging capacity in the total configuration capacity of the energy storage system is determined based on the sign of the maximum amplitude of the power angle.

6. The capacity configuration method for an energy storage system according to claim 5, characterized in that, The determination of the lithium battery configuration capacity that satisfies the maximum amplitude constraint of the power angle includes: If the total capacity is determined to be the discharge capacity, the discharge capacity is calculated based on the available capacity that the lithium battery needs to reserve, the initial SOC of the lithium battery, and the minimum SOC of the lithium battery. If the total configuration capacity is determined to be the charging capacity, then the charging capacity is calculated based on the reservable absorption capacity of the lithium battery, the initial SOC of the lithium battery, and the maximum SOC of the lithium battery.

7. A capacity configuration device for an energy storage system, characterized in that, include: The acquisition unit is used to acquire the maximum amplitude of the power angle of the energy storage system during a fault. If it is determined that the maximum amplitude of the power angle is greater than the preset maximum amplitude threshold, the minimum inertia of the system is acquired. The determination unit is used to obtain the equivalent inertia that the energy storage system needs to provide to meet the maximum amplitude constraint of the power angle based on the minimum inertia of the system, and to determine the total configuration capacity of the energy storage system determined by the maximum amplitude of the power angle based on the equivalent inertia. The configuration unit is used to determine the lithium battery configuration capacity that satisfies the maximum power angle constraint if the total configuration capacity is determined to be greater than the total static energy possessed by the supercapacitor.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1 to 6.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method of any one of claims 1 to 6.

Images