A frequency modulation control method and device based on a sodium-ion battery, and a frequency modulation system

Abstract

The application discloses a frequency modulation control method and device based on a sodium ion battery, and a frequency modulation system. The method comprises the following steps: acquiring power grid frequency and state data of the sodium ion battery, such as voltage, SOC and temperature; and determining the working mode of the sodium ion battery to perform frequency modulation according to the power grid frequency and the state data of the sodium ion battery. According to the method provided in the application, whether the sodium ion battery participates in the frequency modulation of charging and discharging is comprehensively judged through the power grid frequency and multi-dimensional data of the sodium ion battery, such as temperature, SOC and single cell voltage, so as to avoid the deviation of the decision made only according to the SOC, to make the frequency modulation action accurately correspond to the actual adjustable capacity of the battery, and to realize accurate control. By determining the charging and discharging rate in a preset interval and limiting the rate in a safe interval allowed by the current state, the polarization intensification or thermal runaway caused by a large current can be prevented, and the safety of frequency modulation is improved.

Description

Technical Field

[0001] This application belongs to the field of power grid frequency regulation technology, specifically relating to a frequency regulation control method and device, and a frequency regulation system based on sodium-ion batteries. Background Technology

[0002] With the continuous increase in the proportion of new energy power generation, the inertia of the power system is decreasing, load fluctuations are increasing, and the pressure on grid frequency stability control is significantly increasing. Sodium-ion batteries, based on their superior safety performance, low-temperature performance, fast-charging performance, and cost advantages, are gradually being introduced into power system energy storage power stations to undertake functions such as peak shaving, frequency regulation, and backup capacity support.

[0003] However, current frequency regulation methods are mainly designed for mainstream lithium-ion batteries, and most determine the charge / discharge rate of lithium-ion batteries based on the battery's state of charge (SOC) to adjust the grid frequency. However, sodium-ion batteries have significantly different electrochemical response characteristics during charge and discharge compared to lithium-ion batteries. Therefore, using frequency regulation methods based on lithium-ion battery designs to control the charge / discharge rate of sodium-ion batteries will result in poor frequency regulation performance.

[0004] Therefore, there is an urgent need for a frequency modulation control method for sodium-ion batteries. Summary of the Invention

[0005] This application provides a frequency modulation control method, apparatus, and system based on sodium-ion batteries, which can solve the above-mentioned technical problems.

[0006] In a first aspect, embodiments of this application provide a frequency modulation control method based on a sodium-ion battery, the method comprising: Acquire grid frequency and sodium-ion battery status data, the status data including the sodium-ion battery temperature, state of charge and single cell voltage; Based on the power grid frequency and the state data of the sodium-ion battery, the operating mode of the sodium-ion battery is determined for frequency regulation. The operating modes include standby, charging frequency regulation, discharging frequency regulation, and operation prohibited. In standby mode, frequency adjustment is not performed. In the charging / discharging frequency adjustment mode, the sodium-ion battery is charged / discharged at a target rate within a preset rate range to adjust the frequency. In the prohibited operation mode, the sodium-ion battery does not participate in frequency adjustment.

[0007] In one possible implementation of the first aspect, determining the operating mode of the sodium-ion battery for frequency modulation based on the grid frequency and the state data of the sodium-ion battery includes: The operating mode of the sodium-ion battery is determined based on the power grid frequency and the status data. When the operating mode is the charging / discharging frequency modulation mode, the target rate and frequency modulation power are determined according to the operating mode, and frequency modulation is performed with the target rate and the frequency modulation power.

[0008] In one possible implementation of the first aspect, determining the operating mode of the sodium-ion battery based on the grid frequency and the state data includes: The difference between the power grid frequency and the rated frequency is calculated to obtain the power grid frequency deviation; By comparing the magnitude of the power grid frequency deviation with the preset frequency regulation dead zone, it can be determined whether the sodium-ion battery is in the standby mode; If it is not in the standby mode, then determine whether the sodium-ion battery is in the prohibited operation mode based on the status data; If the sodium-ion battery is not in the prohibited operation mode, then the sign of the power grid frequency deviation determines whether the sodium-ion battery is in the charging frequency regulation mode.

[0009] In one possible implementation of the first aspect, determining whether the sodium-ion battery is in the prohibited operation mode based on the state data includes: Compare the relationship between the temperature, state of charge, and cell voltage and the preset temperature range, first charge threshold, and first voltage threshold, respectively. If the temperature is not within the specified temperature range, the state of charge is less than the specified charge threshold, or the single-cell voltage is less than the first voltage threshold, then the sodium-ion battery is determined to be in the prohibited operation mode.

[0010] In one possible implementation of the first aspect, determining the target multiplier based on the operating mode includes: When the sodium-ion battery is in the charging frequency modulation mode, a preset first rate range is determined as the target rate range, and the target rate is determined from the target rate range; When the sodium-ion battery is in the discharge frequency modulation mode, a target rate range is selected from a plurality of preset rate ranges based on the state data; and the target rate is determined from the target rate range.

[0011] In one possible implementation of the first aspect, selecting a target magnification range from a preset plurality of magnification ranges based on the state data includes: Determine whether the individual cell voltage is greater than or equal to a second voltage threshold, whether the state of charge is greater than or equal to a second charge threshold, the second voltage threshold being greater than the first voltage threshold, and the second charge threshold being greater than the first charge threshold; If the single-cell voltage is greater than or equal to the second voltage threshold, and the state of charge is greater than or equal to the second state of charge threshold, then the first rate range is determined as the target rate range; If the single-cell voltage is less than the second voltage threshold and the state of charge is less than the second state of charge threshold, then the second rate range is determined as the target rate range, and the second rate range is a sub-range of the first rate range; Otherwise, the third magnification interval is determined as the target magnification interval, and the third magnification interval is a sub-interval of the second magnification interval.

[0012] In one possible implementation of the first aspect, when the sodium-ion battery is in the standby mode, the method further includes: The charge / discharge rate of the sodium-ion battery is determined within the third rate range to adjust the state of charge of the sodium-ion battery to a preset charge range, which is greater than the second charge threshold.

[0013] In one possible implementation of the first aspect, the frequency modulation power satisfies the following formula:

[0014] in, Indicates the frequency modulation power, , , These are the unit voltage coefficient, state-of-charge coefficient, and temperature coefficient determined according to the aforementioned operating mode. For power grid frequency deviation, For the maximum frequency deviation, This is the rated power.

[0015] Secondly, embodiments of this application provide a frequency modulation control device based on a sodium-ion battery, comprising: a battery management system, a frequency modulation controller, and an energy storage converter; The battery management system is used to acquire the status data of the sodium-ion battery, including the temperature, state of charge, and single-cell voltage of the sodium-ion battery. The frequency controller is used to acquire the power grid frequency; The frequency controller and the energy storage converter are used to determine the operating mode of the sodium-ion battery for frequency regulation based on the grid frequency and the state data of the sodium-ion battery. The operating modes include standby, charging frequency regulation, discharging frequency regulation, and operation prohibited. In standby mode, frequency adjustment is not performed. In the charging / discharging frequency adjustment mode, the sodium-ion battery is charged / discharged at a target rate within a preset rate range to adjust the frequency. In the prohibited operation mode, the sodium-ion battery does not participate in frequency adjustment.

[0016] Thirdly, embodiments of this application provide a frequency modulation system based on a sodium-ion battery, including a sodium-ion battery pack and a frequency modulation control device for the sodium-ion battery; The sodium-ion battery pack includes multiple sodium-ion batteries; The frequency modulation control device is used to acquire the grid frequency and the status data of the sodium-ion battery, the status data including the temperature, state of charge and single cell voltage of the sodium-ion battery; The frequency control device is also used to determine the operating mode of the sodium-ion battery for frequency regulation based on the grid frequency and the state data of the sodium-ion battery. The operating modes include standby, charging frequency regulation, discharging frequency regulation, and prohibition of operation. In standby mode, the sodium-ion battery does not participate in frequency regulation. In the charging / discharging frequency regulation mode, the sodium-ion battery is charged / discharged at a target rate within a preset rate range for frequency regulation. In the prohibited operation mode, the sodium-ion battery does not charge / discharge.

[0017] The beneficial effects of this application embodiment compared with the prior art are as follows: The method provided in this application determines whether to perform frequency regulation of sodium-ion battery charging / discharging by using multi-dimensional data such as grid frequency and sodium-ion battery temperature, SOC, and single cell voltage. It can make judgments based on grid frequency demand coupled with multiple parameters such as temperature and voltage, avoiding the adaptive bias when making decisions solely based on state of charge, and making the frequency regulation action accurately correspond to the actual adjustable capability of the battery, thus achieving precise control of sodium-ion battery; by determining the charge / discharge rate of sodium-ion battery within a preset range, the target rate can be limited to the safe range allowed by the current state of sodium-ion battery, preventing the risk of increased polarization or thermal runaway caused by high current charging and discharging, and improving the safety of sodium-ion battery during frequency regulation. Attached Figure Description

[0018] Figure 1 A flowchart illustrating the implementation of a frequency modulation control method based on a sodium-ion battery, provided in an embodiment of this application; Figure 2 A flowchart illustrating the implementation of a method for determining the charge / discharge rate of a sodium-ion battery, provided in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of a frequency modulation system for a sodium-ion battery provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a frequency modulation control device for a sodium-ion battery provided in an embodiment of this application. Detailed Implementation

[0019] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0020] It should be understood that, when used in this application specification and, the term "comprising" indicates the presence of the described feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0021] It should also be understood that the term “and / or” as used in this application specification and in the specification means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0022] As used in this application specification and in the present application, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determination" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determination," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0023] Furthermore, in the description of this application and its contents, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0025] Traditional frequency regulation control methods for lithium-ion batteries mostly determine whether frequency regulation is needed based on the grid frequency deviation (i.e., the difference between the grid frequency and its rated frequency), and then determine the charge / discharge rate of the battery based on its state of charge (SOC). This method is only applicable to lithium-ion batteries and not to sodium-ion batteries.

[0026] Specifically, lithium-ion batteries, due to their small ionic radius, small Stokes radius, and low desolvation energy barrier, exhibit "ohmic-like" response characteristics over a wide SOC range—polarization and current are approximately linear, and the relationship between SOC and open-circuit voltage is stable. Therefore, the charge / discharge rate of lithium-ion batteries can be effectively and accurately controlled solely by SOC.

[0027] However, due to its intrinsic characteristics and material structure limitations, the electrochemical performance of sodium-ion batteries varies in segments with factors such as temperature and voltage, and the maximum charge / discharge rate that can be tolerated varies greatly in different ranges.

[0028] For example, sodium-ion batteries can maintain stable rate performance and cycle capacity in low-temperature environments, have strong wide-temperature range operation capabilities, and can achieve high-rate charging of 1C to 1.5C across the entire SOC range; they can stably perform high-rate discharging of 1C to 1.5C in the high-voltage region where the single-cell voltage is relatively high, but the rate capability decreases significantly when the single-cell voltage is low, and the discharge loss and temperature rise increase rapidly.

[0029] Therefore, the SOC value alone cannot guarantee the accuracy and safety of sodium-ion batteries during frequency modulation.

[0030] In view of this, this application provides a frequency regulation control method based on sodium-ion batteries. It determines whether to perform frequency regulation for charging / discharging the sodium-ion battery by using multi-dimensional data such as grid frequency and the sodium-ion battery's temperature, state of charge (SOC), and individual cell voltage. This method can make judgments based on the coupling of grid frequency requirements with multiple parameters such as temperature and voltage, avoiding the adaptive bias that occurs when relying solely on state of charge. This ensures that the frequency regulation action precisely corresponds to the battery's current adjustable capability, achieving precise control of the sodium-ion battery. Furthermore, it determines the charge / discharge rate within a preset range, limiting the rate to a safe range allowed by the current state of the sodium-ion battery. This prevents the risk of increased polarization or thermal runaway caused by high-current charging and discharging, improving the safety of the sodium-ion battery during frequency regulation.

[0031] The present application will be described in further detail below with reference to specific embodiments, but the implementation of the present application is not limited thereto.

[0032] Figure 1 The diagram shown illustrates a frequency modulation control method based on a sodium-ion battery, as provided in an embodiment of this application. As an example and not a limitation, method 100 may include steps S101-S102, which are described below.

[0033] S101, acquire grid frequency and sodium-ion battery status data.

[0034] For example, the state data of a sodium-ion battery may include the temperature, state of charge (SOC) value, and single-cell voltage of the sodium-ion battery.

[0035] Specifically, the system can acquire grid frequency and sodium-ion battery status data in real time, or acquire this data periodically; then, based on this data and the operating mode of the sodium-ion battery, the system can adjust the operating mode of the sodium-ion battery in real time / timed to respond promptly to the grid frequency.

[0036] S102 determines the operating mode of the sodium-ion battery for frequency regulation based on the grid frequency and the state data of the sodium-ion battery.

[0037] For example, the operating modes of a sodium-ion battery may include standby mode, charging frequency modulation mode, discharging frequency modulation mode, and shutdown mode.

[0038] Specifically, frequency regulation is not performed when the grid frequency is not significantly different from the grid's rated frequency.

[0039] Specifically, when the sodium-ion battery is in an abnormal state and is not in a safe state that allows for charging / discharging (i.e., in a prohibited operating mode), the sodium-ion battery will not participate in frequency regulation.

[0040] For example, if a sodium-ion battery is in an abnormal state, charging / discharging it will cause battery damage and a series of safety problems such as short circuits and fires. In this case, the sodium-ion battery can be put into a prohibited operation mode.

[0041] Optionally, abnormal information can be generated for sodium-ion batteries in prohibited operating mode, reported to the user, or operations such as cooling can be performed to remove them from prohibited operating mode and return them to normal state.

[0042] It should be understood that multiple sodium-ion battery packs are installed in the power grid, and each sodium-ion battery pack contains multiple sodium-ion batteries. During frequency regulation, the states of different sodium-ion batteries are not entirely the same. The sodium-ion battery is the smallest control unit, which can charge / discharge some sodium-ion batteries that are not in the prohibited operating mode to regulate the frequency, and continuously monitor the sodium-ion batteries that are in the prohibited operating mode.

[0043] Specifically, when the grid frequency is high and the sodium-ion battery's status data is normal, the sodium-ion battery is in charging frequency regulation mode. The target charging rate within a preset range can be used to charge the sodium-ion battery, thereby reducing the grid frequency.

[0044] Specifically, when the grid frequency is low and the sodium-ion battery's status data is normal, the sodium-ion battery is in discharge frequency regulation mode, which allows the sodium-ion battery to discharge at a target rate within a preset range, thereby increasing the grid frequency.

[0045] In one example, the operating mode of the sodium-ion battery can be determined first based on the grid frequency and status data. When the sodium-ion battery is in charge / discharge frequency regulation mode, the target rate and frequency regulation power can be determined based on the operating mode, and the sodium-ion battery can be controlled to charge / discharge at the target rate and frequency regulation power to regulate the frequency.

[0046] The method provided in this application determines whether to perform frequency regulation for charging / discharging of sodium-ion batteries by using multi-dimensional data such as grid frequency and sodium-ion battery temperature, SOC, and single-cell voltage. It can make judgments based on grid frequency requirements coupled with multiple parameters such as temperature and voltage, avoiding the adaptive bias when making decisions solely based on state of charge. This ensures that the frequency regulation action precisely corresponds to the actual adjustable capability of the battery, achieving precise control of the sodium-ion battery. By determining the charge / discharge rate of the sodium-ion battery within a preset range, the target rate can be limited to the safe range allowed by the current state of the sodium-ion battery, preventing the risk of increased polarization or thermal runaway caused by high current charging and discharging, and improving the safety of sodium-ion batteries during frequency regulation.

[0047] Figure 2 The diagram illustrates a method for determining the charge / discharge rate of a sodium-ion battery according to an embodiment of this application. As an example and not a limitation, method 200 can be a specific possible implementation of step S102 in method 100 described above. Method 200 may include steps S201-S208, which are described below.

[0048] S201, calculate the difference between the grid frequency and the rated frequency to obtain the grid frequency deviation.

[0049] For example, the rated frequency is typically 50Hz.

[0050] S202, compare the relationship between the grid frequency deviation and the frequency regulation dead zone to determine whether the sodium-ion battery is in standby mode.

[0051] In one example, if the grid frequency deviation is not within the frequency regulation dead zone, it means that the current grid frequency deviation is large and frequency regulation is required. The sodium-ion battery is not in standby mode and the subsequent step S203 needs to be performed.

[0052] For example, the FM dead zone interval can be represented as [- , ], The length of the FM dead zone. It can be 0.05Hz.

[0053] For example, if the grid frequency is originally 50.05Hz, which is within the frequency regulation dead zone, and at a certain moment the grid frequency rises to 50.15Hz, the grid frequency deviation is +0.15Hz, exceeding 0.05Hz. At this time, the following step S203 can be performed.

[0054] In another example, if the grid frequency deviation is within the frequency regulation dead zone, it means that the current grid frequency deviation is within a tolerable range and frequency regulation is not required, and the sodium-ion battery is in standby mode.

[0055] For example, when the sodium-ion battery is in standby mode, it can be charged and discharged at a lower rate to keep the sodium-ion battery in an optimal state, i.e., within a preset charge range, so that it can directly enter a high-rate operation state during subsequent frequency regulation.

[0056] Specifically, this smaller multiplier can be within the third multiplier range, which can be [0.1C, 0.25C].

[0057] Specifically, the preset charge range can be [45%, 75%].

[0058] Optionally, if the sodium-ion battery operates under high temperature conditions for a long time, the size of the charging range can be appropriately reduced to reduce the risk of heat accumulation under high SOC conditions; if the sodium-ion battery operates under low temperature conditions for a long time, the size of the charging range can be appropriately increased to improve the discharge rate stability under low temperature conditions.

[0059] Optionally, the above-mentioned shallow charge and discharge maintenance operation can be performed periodically according to the cumulative number of frequency regulation cycles of the battery, so that the battery operates in a medium SOC range, thereby reducing polarization accumulation and restoring battery activity, and thus delaying cycle life decay.

[0060] S203 determines whether the sodium-ion battery is in a prohibited operating mode based on the status data.

[0061] In one possible implementation, the relationship between temperature, SOC, single cell voltage and preset temperature range, first charge threshold and first voltage threshold can be compared, and the sodium-ion battery can be determined as to whether it is in a prohibited operation mode based on the comparison results.

[0062] For example, the preset temperature range can be [-20℃, 55℃], the first charge threshold can be 10%, and the first voltage threshold can be 2.5V.

[0063] In one example, if the temperature of the sodium-ion battery is not within the preset temperature range, the SOC is less than the first charge threshold, or the single cell voltage is less than the first voltage threshold, then the sodium-ion battery is determined to be in a prohibited operation mode. Subsequent processes can be stopped, high-rate frequency modulation operation can be locked, and protection control and alarm mechanisms can be activated to prevent safety risks under abnormal conditions such as battery over-discharge, overheating, and abnormal operation, and to ensure the safe and stable operation of the sodium-ion battery pack.

[0064] In one example, if the temperature of the sodium-ion battery is within the temperature range and the SOC and single-cell voltage are greater than the first charge threshold and the first voltage threshold, respectively, then step S204 can be performed.

[0065] For example, continuing with the example above, if the sodium-ion battery is detected to have a temperature of 35°C, a state of charge (SOC) of 45%, a voltage of 3.2V, a temperature within the range of [-20°C, 55°C], and an SOC greater than 10% and a voltage greater than 2.5V, then step S204 can be performed.

[0066] S204 determines whether the sodium-ion battery is in charging frequency regulation mode based on the sign of the grid frequency difference.

[0067] In one example, if the grid frequency difference is positive, it means that the grid frequency needs to be reduced. Then, it can be determined that the sodium-ion battery is in the charging frequency regulation mode and step S205a is performed to charge the sodium-ion battery to reduce the grid frequency.

[0068] For example, if the grid frequency drops to 49.85Hz and the grid frequency deviation is -0.155Hz, the working mode of the sodium-ion battery can be set to charging frequency regulation mode, and the following steps S205a can be performed.

[0069] In another example, if the grid frequency difference is negative, it indicates that the grid frequency needs to be increased. In this case, it can be determined that the sodium-ion battery is in discharge frequency regulation mode and step S205b is performed to discharge the sodium-ion battery to increase the grid frequency.

[0070] For example, if the grid frequency increases to 50.15Hz and the grid frequency deviation is +0.15Hz, the working mode of the sodium-ion battery can be determined as the discharge frequency regulation mode, and the following steps S205b can be performed.

[0071] S205a, the preset first magnification range is determined as the target magnification range.

[0072] For example, the first multiplier range can be [0C, 1.5C].

[0073] Sodium-ion batteries can be charged at high rates of 1C to 1.5C across the entire range, with low temperature rise and minimal thermal constraint during charging. They also have a fast dynamic response capability, allowing the target rate to be determined within a relatively large first-rate range.

[0074] Specifically, the charging frequency regulation mode of sodium-ion batteries is mainly used for fast frequency regulation operation in the scenario of grid power absorption. It is suitable for charging regulation needs in primary frequency regulation, fast frequency regulation and deep frequency regulation, and can meet the requirements of high frequency and high response speed frequency regulation services.

[0075] S205b selects the target magnification range from the preset magnification range based on the status data.

[0076] In one possible implementation, the relationship between the single-cell voltage, SOC, and the second voltage threshold and second charge threshold of the sodium-ion battery can be compared separately, and the target rate range can be selected based on the comparison results.

[0077] For example, the second voltage threshold is greater than the first voltage threshold; for instance, the second voltage threshold could be 2.7V.

[0078] For example, the second charge threshold is greater than the first charge threshold but less than the charge range. For instance, the second charge threshold could be 20%.

[0079] For example, there may be multiple preset magnification ranges, including at least a first magnification range and a second magnification range.

[0080] Specifically, the first and second voltage thresholds, the endpoints of the temperature range, and the first and second charge thresholds are generally determined by the phase transition critical values ​​of the sodium-ion battery during charging / discharging.

[0081] For example, the second magnification range can be a sub-range of the first magnification range, and the third magnification range can be a sub-range of the second magnification range. For instance, the second magnification range can be [0C, 0.5C].

[0082] In one example, if the single cell voltage of the sodium-ion battery is greater than or equal to the second voltage threshold and the state of charge (SOC) of the sodium-ion battery is greater than or equal to the second charge threshold, it can be determined that the sodium ions have entered a specific first discharge frequency modulation mode, and the first rate range is determined as the target rate range.

[0083] For example, continuing with the example above, when the temperature of the sodium-ion battery is 35°C, the SOC is 45%, and the voltage is 3.2V, the SOC is greater than 20% and the voltage is greater than 2.7V, the sodium-ion battery can be switched to the first discharge frequency regulation mode.

[0084] For example, see Table 1 below, which shows the correspondence between the charge / charge rate and various state parameters of a certain type of sodium-ion battery. When the temperature of the sodium-ion battery is within the temperature range, the SOC is at [second charge threshold, 100%] and the single cell voltage is greater than or equal to the second voltage threshold, the maximum discharge rate that the sodium-ion battery can tolerate is relatively high. The first rate range can be determined as the target rate range.

[0085] Table 1

[0086] In the first discharge frequency regulation mode, sodium-ion batteries exhibit low temperature rise during discharge, high operational stability, and the ability to continuously output high frequency regulation power. Therefore, the first discharge frequency regulation mode is primarily used for fast discharge frequency regulation and deep short-time frequency regulation scenarios. It is suitable for the core discharge requirements in primary frequency regulation, secondary frequency regulation, and Automatic Generation Control (AGC) frequency regulation, and represents the main operating range in which sodium-ion battery packs are given priority for participating in high-yield frequency regulation services. In another example, if the single cell voltage of the sodium-ion battery is less than the second voltage threshold and the state of charge (SOC) of the sodium-ion battery is less than the second charge threshold, then the sodium-ion battery can be determined to enter a specific second discharge frequency modulation mode, and the second rate range can be determined as the target rate range.

[0087] For example, referring to Table 1 above, if the temperature of the sodium-ion battery is within the temperature range, the single cell voltage is within [first voltage threshold, second voltage threshold), and the SOC is within [first charge threshold, second charge threshold), the maximum tolerable discharge rate of the sodium-ion battery is relatively low, and the second rate range can be determined as the target rate range.

[0088] Specifically, as shown in Table 1, when sodium ions are in the second discharge frequency regulation mode, their discharge rate should be limited to no more than 0.5C to reduce the risk of temperature rise and capacity decay caused by high-rate discharge in the low-voltage region, and to ensure battery operation safety and lifespan stability. The second discharge frequency regulation mode is mainly used for backup frequency regulation and low-power auxiliary frequency regulation scenarios, and is suitable for long-term low-power regulation needs, reducing battery operating losses while ensuring the continuity of system frequency regulation.

[0089] In another example, if a sodium-ion battery meets the following conditions: the temperature is within a certain temperature range, the single-cell voltage is within [a first voltage threshold, a second voltage threshold], and the state of charge (SOC) is greater than a second charge threshold; or the temperature is within a certain temperature range, the single-cell voltage is greater than a second voltage threshold, and the SOC is within [a first charge threshold, a second charge threshold], then the sodium-ion battery can be determined to enter the third discharge frequency modulation mode, discharging at a lower rate. For example, the third multiplier range can be used as the target multiplier range at this time.

[0090] Specifically, the first, second, or third multiplier range is one of a set of preset multiplier ranges.

[0091] By selecting the target rate range for battery charging and discharging based on battery state data, dynamic matching between the charging and discharging capacity of sodium-ion batteries and the frequency regulation requirements of the power grid can be achieved. This ensures fast frequency regulation performance while reducing heat loss and lifespan degradation, thereby improving the operational stability and economy of sodium-ion battery packs.

[0092] S206, determine the target rate of the sodium-ion battery from the target rate range.

[0093] Generally, the target multiplier can be the maximum value that can be used within the target multiplier range.

[0094] It should be understood that if the sodium-ion battery is in charging frequency regulation mode, the target rate is the charging rate of the battery; if the sodium-ion battery is in discharging frequency regulation mode, the target rate is the discharging rate.

[0095] S207 determines the frequency modulation power based on the operating mode.

[0096] In one possible implementation, the cell voltage coefficient, state-of-charge coefficient, and temperature coefficient can be determined first based on the operating mode of the sodium-ion battery; then, the frequency regulation power can be calculated based on these coefficients and the grid frequency.

[0097] For example, the frequency modulation power satisfies the following formula:

[0098] in, Indicates the maximum frequency modulation power. , , These are the unit voltage coefficient, state-of-charge coefficient, and temperature coefficient, respectively. For power grid frequency deviation, For the maximum frequency deviation, for example, 0.5Hz, This is the rated power.

[0099] This application uses a frequency deviation adjustment factor. Dynamically determining the frequency regulation power can increase the frequency regulation power when the grid frequency deviation is large and decrease it when it is small, thereby achieving dynamic matching between frequency regulation demand and battery charging / discharging.

[0100] In one example, the single-cell voltage coefficient can reflect the charge and discharge rate of a sodium-ion battery in different voltage ranges, the state-of-charge coefficient can reflect the charge and discharge rate constraints under different states of charge, and the temperature coefficient can reflect the rate correction capability under different operating temperature conditions.

[0101] For example, referring to Table 2 below, regarding the single-cell voltage coefficient, when the sodium-ion battery is in charging frequency modulation mode, high-rate charging operation is allowed across the entire SOC range. Therefore... The value is 1.5; when sodium ions are in the first discharge frequency modulation mode, high-rate discharge operation is allowed. The value is 1.5; when in the second discharge frequency modulation mode, it enters the power-limited operation state. The value is 0.5; in the disabled operation mode, since the battery does not charge or discharge, there is no need to calculate the maximum power; in standby mode, no frequency adjustment is performed, so... It is 0.

[0102] For example, referring to Table 2 below, regarding the state of charge (SOC), sodium-ion batteries, when in charging frequency modulation mode, possess high-rate charging capability across the entire SOC range. Therefore... The value is 1; when sodium ions are in the first discharge frequency modulation mode, high-rate discharge operation is allowed. The value is 1; when in the second discharge frequency modulation mode, it enters the power-limited operation state. The value is 0.5; in the disabled operation mode, since the battery does not charge or discharge, there is no need to calculate the maximum power; in standby mode, no frequency adjustment is performed, so... It is 0.

[0103] For example, referring to Table 2 below, regarding the temperature coefficient, when the sodium-ion battery is not in standby or disabled operation mode, it can be determined in segments according to the temperature. If the temperature is low, for example, between -20℃ and -10℃, a low-temperature compensation strategy can be used to maintain the charging rate. The compensation coefficient is dynamically adjusted using linear interpolation, setting it to 0.8 at -20℃ and 1 at -10℃. When the temperature is moderate, for example, between -10℃ and 40℃, full-rate operation is allowed to fully utilize the high-rate charging capability of the sodium-ion battery across its entire SOC range. The value is 1.0; when the temperature is high, linear derating control can be implemented based on a linear function to gradually reduce the charge and discharge rate, thereby reducing the risk of heat accumulation and side reactions.

[0104] Sodium-ion batteries, when in charging frequency modulation mode, possess high-rate charging capability across the entire SOC range, therefore The value is 1; when sodium ions are in the first discharge frequency modulation mode, high-rate discharge operation is allowed. The value is 1; when in the second discharge frequency modulation mode, it enters the power-limited operation state. The value is 0.5; in the disabled operation mode, since the battery does not charge or discharge, there is no need to calculate the maximum power; in standby mode, no frequency adjustment is performed, so... It is 0.

[0105] Table 2

[0106] For example, when the battery performance is as shown in Table 1 above, the single-cell voltage coefficient, state-of-charge coefficient, and temperature coefficient can satisfy the following formulas:

[0107] .

[0108] For example, when a sodium-ion battery is in charging frequency regulation mode, the temperature... Taking a temperature of 35℃, a state of charge (SOC) of 45%, and a voltage of 3.2V as an example, referring to the values ​​of the coefficients shown in the formula above, the frequency modulation power can be calculated. .

[0109] For example, taking a sodium-ion battery in first-level discharge frequency regulation mode, with U=3.15V and T=32℃, the calculated frequency regulation power is 1.5MW.

[0110] Optionally, if the battery is in the second discharge frequency regulation mode, the frequency can be increased by 0.3-0.5 times. As a frequency-modulated power source, it reduces the temperature rise and cycle decay caused by high-rate discharge in the low-voltage region.

[0111] S208 controls the sodium-ion battery to charge / discharge using a target rate and frequency-modulated power.

[0112] For example, after determining the target rate of a sodium-ion battery, it can be controlled to charge / discharge at the target rate for frequency modulation.

[0113] For example, when a sodium-ion battery is in charging frequency modulation mode, the frequency modulation power is... This allows it to operate at a multiplier of 1.5C. The system was charged using regulated power, during which the temperature rise was close to zero, and no significant heat accumulation was observed. After approximately 10 seconds, the grid frequency returned to 50.0Hz, the regulated power requirement was removed, and the sodium-ion battery returned to standby mode. After returning to standby mode, the sodium-ion battery was charged / discharged at a rate of 0.2C to maintain its SOC at around 60%.

[0114] The method provided in this application determines whether to perform frequency regulation for charging / discharging of the sodium-ion battery by using multi-dimensional data such as grid frequency and sodium-ion battery temperature, SOC, and single-cell voltage. It can make judgments based on grid frequency requirements coupled with multiple parameters such as temperature and voltage, avoiding the adaptive bias when making decisions solely based on state of charge. This ensures that the frequency regulation action precisely corresponds to the battery's current actual adjustable capability, achieving precise control of the sodium-ion battery. Furthermore, it determines the charge / discharge rate within a preset range, limiting the rate to a safe range allowed by the current state of the sodium-ion battery. This prevents the risk of increased polarization or thermal runaway caused by high-current charging and discharging, improving the safety of the sodium-ion battery during frequency regulation.

[0115] Furthermore, by determining the target rate within a larger first-rate range when the battery is in optimal condition, and prioritizing charging / discharging at higher rates, the frequency regulation response speed and available adjustable capacity can be improved. When there is no frequency regulation requirement, determining the target rate from a third-rate range allows the battery to preferentially reside near the first-level frequency regulation zone during discharge, ensuring that subsequent frequency regulation tasks can quickly enter a high-rate operating state. Therefore, the method provided in this application can fully utilize the characteristics of sodium-ion batteries, which have high-rate discharge capabilities throughout the full SOC range of charging and in the high-voltage range of discharging, thus avoiding the problems of traditional lithium-ion batteries, such as the need to limit the charging rate in the high SOC range and the significant decrease in rate capability under low-temperature conditions.

[0116] Figure 3 The diagram shown is a schematic representation of a frequency modulation system for a sodium-ion battery according to an embodiment of this application. As an example and not a limitation, system 300 may include at least one sodium-ion battery pack 310 and a frequency modulation control device 320.

[0117] In some embodiments, see Figure 3 The sodium-ion battery pack 310 may include multiple sodium-ion batteries. The frequency regulation control device 320 can obtain the grid frequency from the power grid and acquire the state data of each sodium-ion battery in the sodium-ion battery pack 310. Then, based on the grid frequency and the state data of the sodium-ion batteries, the frequency regulation control device determines the operating mode of the sodium-ion batteries for frequency regulation.

[0118] For example, the state data of a sodium-ion battery may include the temperature, state of charge, and single-cell voltage of the sodium-ion battery.

[0119] For example, the operating modes of a sodium-ion battery may include standby, charging frequency modulation, discharging frequency modulation, and inoperability.

[0120] Specifically, in standby mode, the sodium-ion battery does not participate in frequency regulation; in charge / discharge frequency regulation mode, the sodium-ion battery charges / discharges at a target rate within a preset range; and in prohibited operation mode, the sodium-ion battery does not charge / discharge.

[0121] The system provided in this application determines whether to perform frequency regulation for charging / discharging of sodium-ion batteries by using multi-dimensional data such as grid frequency and sodium-ion battery temperature, SOC, and single-cell voltage. It can make judgments based on grid frequency requirements coupled with multiple parameters such as temperature and voltage, avoiding the adaptive bias when making decisions solely based on state of charge. This ensures that the frequency regulation action precisely corresponds to the actual adjustable capability of the battery, achieving precise control of the sodium-ion battery. Furthermore, it determines the charge / discharge rate within a preset range, limiting the rate to a safe range allowed by the current state of the sodium-ion battery. This prevents the risk of increased polarization or thermal runaway caused by high-current charging and discharging, improving the safety of the sodium-ion battery during frequency regulation.

[0122] Furthermore, the system uses sodium-ion batteries for energy storage / function, which can fully utilize the unique electrochemical characteristics of sodium-ion batteries, such as achieving high-rate charging of 1C to 1.5C with minimal temperature rise, stable high-rate discharge in the high-voltage range with low loss, strong wide-temperature range operation capability, low cost, and high thermal stability. This improves the stability of the system in high and low temperature environments, thereby enhancing the system's applicability under complex environmental conditions. At the same time, it increases the effective adjustable capacity of the system in frequency-tunable scenarios.

[0123] Experiments have shown that the usable capacity of the frequency modulation system is increased by about 40% to 60% compared with the traditional lithium battery energy storage system.

[0124] Figure 4 This is a schematic diagram of a frequency modulation control device for a sodium-ion battery provided in an embodiment of this application. Device 400 may include a battery management system 410, a frequency modulation controller 420, and an energy storage converter 430. It should be understood that device 400 here is the same type of frequency modulation control device as the aforementioned frequency modulation control device 320.

[0125] In some embodiments, the battery management system 410 can be used to acquire the state data of the sodium-ion battery, the frequency controller 420 can be used to acquire the grid frequency, and the frequency controller 420 and the energy storage converter 430 can be used together to determine the operating mode of the sodium-ion battery for frequency regulation based on the grid frequency and the state data of the sodium-ion battery.

[0126] For example, see Figure 4 The input terminal of the battery management system 410 is connected to the sodium-ion battery, and the output terminal is connected to the first input terminal of the frequency controller 420. The second input terminal of the frequency controller 420 is used to receive the grid frequency signal, and the output terminal is connected to the input terminal of the energy storage converter 430. The output terminal of the energy storage converter 430 is connected to the sodium-ion battery.

[0127] For example, the state data of a sodium-ion battery may include the temperature, state of charge, and single-cell voltage of the sodium-ion battery.

[0128] For example, the operating modes of a sodium-ion battery may include standby, charging frequency modulation, discharging frequency modulation, and inoperability.

[0129] Specifically, the sodium-ion battery does not adjust the frequency in standby mode, charges / discharges at the target rate within a preset range in charging / discharging frequency adjustment mode, and does not participate in frequency adjustment in the prohibited operation mode.

[0130] In one possible implementation, the battery management system 410 may include a voltage acquisition module 411, a SOC estimation module 412, and a temperature acquisition module 413, which are used to acquire the single-cell voltage, SOC, and temperature of the sodium-ion battery, respectively.

[0131] Optionally, see Figure 4 The battery management system 410 may also include a balance management status monitoring module 414, which is used to detect the operating status of the sodium-ion battery to determine feedback and control signals such as the power limit of the sodium-ion battery, whether it is in a prohibited operating mode, and temperature limit.

[0132] In one possible implementation, the frequency controller 420 can determine the operating mode of the sodium-ion battery based on the grid frequency and state data. When the operating mode is a charge / discharge frequency regulation mode, the frequency controller 420 can also determine the target rate and frequency regulation power based on the operating mode. The energy storage converter 430 can generate a frequency regulation command based on the operating mode, target rate, and frequency regulation power, causing the sodium-ion battery to charge / discharge at the target rate and frequency regulation power for frequency regulation.

[0133] In one example, see Figure 4 The frequency modulation controller 420 may include a state determination module 421 and a state machine module 422. The state determination module 421 is used to determine the current operating mode of the sodium-ion battery, and the state machine module 422 is used to switch the state of the sodium-ion battery to its current operating mode.

[0134] For example, the state determination module 421 can calculate the difference between the grid frequency and the rated frequency to obtain the grid frequency deviation, and compare the grid frequency deviation with the preset frequency regulation dead zone to determine whether the sodium-ion battery is in standby mode. If it is determined that the sodium-ion battery is not in standby mode, it is determined whether the sodium-ion battery is in a prohibited operation mode based on the state data. If the sodium-ion battery is not in a prohibited operation mode, it is determined whether the sodium-ion battery is in a charging frequency regulation mode based on the sign of the grid frequency deviation.

[0135] Specifically, the state determination module 421 can compare the magnitude of the grid frequency deviation with the preset frequency regulation dead zone. If the grid frequency deviation is within the frequency regulation dead zone, it is determined that the sodium-ion battery is in standby mode; otherwise, it is determined that it is not in standby mode.

[0136] Specifically, the state determination module 421 can compare the temperature, state of charge, and cell voltage with the preset temperature range, first charge threshold, and first voltage threshold respectively; if the temperature is not within the temperature range, the state of charge is less than the charge threshold, or the cell voltage is less than the first voltage threshold, then the sodium-ion battery is determined to be in the prohibited operation mode; otherwise, the sodium-ion battery is determined not to be in the prohibited operation mode.

[0137] As an example, the frequency controller 420 may also include a temperature protection module that monitors the battery temperature and generates a status command when the sodium-ion battery temperature is outside the temperature range, so that the status determination module 421 determines that the battery is in a prohibited operation mode.

[0138] Specifically, when the grid frequency deviation is positive, it can be determined that the sodium-ion battery is in charging frequency regulation mode; when the grid frequency deviation is negative, it can be determined that the sodium-ion battery is in discharging frequency regulation mode.

[0139] In one example, the frequency modulation controller 420 further includes a frequency modulation capability quantization module. When the sodium-ion battery is in a charging frequency modulation mode, the frequency modulation capability quantization module is used to determine a preset first rate range as a target rate range, and determine the target charging rate of the sodium-ion battery from the target rate range. When the sodium-ion battery is in a discharging frequency modulation mode, the frequency modulation capability quantization module is used to select a target rate range from a preset plurality of rate ranges based on state data, and determine the target discharging rate of the sodium-ion battery from the target rate range.

[0140] For example, the frequency modulation capability quantization module can determine whether the individual cell voltage is greater than or equal to a second voltage threshold, whether the state of charge is greater than or equal to a second charge threshold, whether the second voltage threshold is greater than a first voltage threshold, and whether the second charge threshold is greater than a first charge threshold. If the individual cell voltage is greater than or equal to the second voltage threshold and the state of charge is greater than or equal to the second charge threshold, then the first rate range is determined as the target rate range. If the individual cell voltage is less than the second voltage threshold and the state of charge is less than the second charge threshold, then the second rate range is determined as the target rate range. Otherwise, the third rate range is determined as the target rate range.

[0141] For example, the second multiplier interval is a sub-interval of the first multiplier interval, and the third multiplier interval is a sub-interval of the second multiplier interval.

[0142] In one example, the frequency modulation controller 420 may also include a power distribution module for determining the frequency modulation power.

[0143] For example, the frequency modulation power satisfies the following formula:

[0144] in, Indicates frequency modulation power. , , These are the unit voltage coefficient, state-of-charge coefficient, and temperature coefficient, determined according to the operating mode. For power grid frequency deviation, For the maximum frequency deviation, This is the rated power.

[0145] In one example, the frequency modulation controller 420 may further include a SOC anchoring module for determining the charge / discharge rate of the sodium-ion battery within a third rate range when the sodium-ion battery is in standby mode, so as to adjust the state of charge of the sodium-ion battery within a preset charge range, the charge range being greater than a second charge threshold; the third rate range is a sub-range of the second rate range.

[0146] For example, the temperature protection module can also be used to dynamically adjust the temperature coefficient according to the temperature of the sodium-ion battery, so that when the battery temperature is moderate, it can charge / discharge at a high rate to achieve rapid frequency support; in low-temperature environments with lower battery temperatures, a low-temperature compensation control strategy can be used to maintain the charging rate to ensure the stability of frequency modulation operation under low-temperature conditions; and when the battery temperature is high, the charging rate can be gradually reduced according to the temperature change.

[0147] By prioritizing the maintenance of the battery's state of charge near the [first charge threshold, second charge threshold] during standby, the single-cell voltage of the sodium-ion battery can remain in the stable range of high-rate discharge capability for a long time, ensuring that subsequent frequency regulation tasks can quickly enter the high-rate operation state (i.e., the first discharge frequency regulation mode).

[0148] In one example, the energy storage converter 430 can be a bidirectional converter.

[0149] The device provided in this application determines whether to perform frequency regulation for charging / discharging of the sodium-ion battery by using multi-dimensional data such as grid frequency and sodium-ion battery temperature, SOC, and single-cell voltage. It can make judgments based on grid frequency requirements coupled with multiple parameters such as temperature and voltage, avoiding the adaptive bias when making decisions solely based on state of charge. This ensures that the frequency regulation action precisely corresponds to the actual adjustable capability of the battery, achieving precise control of the sodium-ion battery. Furthermore, it determines the charge / discharge rate within a preset range, limiting the rate to a safe range allowed by the current state of the sodium-ion battery. This prevents the risk of increased polarization or thermal runaway caused by high-current charging and discharging, improving the safety of the sodium-ion battery during frequency regulation.

[0150] Furthermore, the device provided in this application adopts a control architecture that combines a finite state machine with a frequency modulation capability quantization model. The overall logic is clear and the state switching is well-defined, which can effectively avoid control conflicts and system oscillation problems caused by the concurrent use of multiple control strategies.

[0151] Because the device provided in this application only needs to collect basic operating parameters such as grid frequency, battery cell voltage, SOC, and temperature during engineering implementation, it can be directly deployed in sodium-ion battery energy storage systems without the need for complex hardware structures or special power conversion devices. Therefore, the device provided in this application has strong engineering feasibility, system compatibility, and industrialization promotion value.

[0152] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

Claims

1. A frequency modulation control method based on a sodium-ion battery, characterized in that, include: Acquire grid frequency and sodium-ion battery status data, the status data including the sodium-ion battery temperature, state of charge and single cell voltage; Based on the power grid frequency and the state data of the sodium-ion battery, the operating mode of the sodium-ion battery is determined for frequency regulation. The operating modes include standby, charging frequency regulation, discharging frequency regulation, and operation prohibited. In standby mode, frequency adjustment is not performed. In the charging / discharging frequency adjustment mode, the sodium-ion battery is charged / discharged at a target rate within a preset rate range to adjust the frequency. In the prohibited operation mode, the sodium-ion battery does not participate in frequency adjustment.

2. The method according to claim 1, characterized in that, The step of determining the operating mode of the sodium-ion battery for frequency regulation based on the power grid frequency and the state data of the sodium-ion battery includes: The operating mode of the sodium-ion battery is determined based on the power grid frequency and the status data. When the operating mode is the charge / discharge frequency modulation mode, the target rate and frequency modulation power are determined according to the operating mode, and frequency modulation is performed with the target rate and the frequency modulation power.

3. The method according to claim 2, characterized in that, Determining the operating mode of the sodium-ion battery based on the grid frequency and the status data includes: The difference between the power grid frequency and the rated frequency is calculated to obtain the power grid frequency deviation; By comparing the magnitude of the power grid frequency deviation with the preset frequency regulation dead zone, it can be determined whether the sodium-ion battery is in the standby mode; If the sodium-ion battery is not in the standby mode, then determine whether the sodium-ion battery is in the prohibited operation mode based on the status data; If the sodium-ion battery is not in the prohibited operation mode, then the sign of the power grid frequency deviation determines whether the sodium-ion battery is in the charging frequency regulation mode.

4. The method according to claim 3, characterized in that, Determining whether the sodium-ion battery is in the prohibited operation mode based on the status data includes: Compare the relationship between the temperature, state of charge, and cell voltage and the preset temperature range, first charge threshold, and first voltage threshold, respectively. If the temperature is not within the specified temperature range, the state of charge is less than the specified charge threshold, or the single-cell voltage is less than the first voltage threshold, then the sodium-ion battery is determined to be in the prohibited operation mode.

5. The method according to claim 4, characterized in that, Determining the target scaling factor based on the operating mode includes: When the sodium-ion battery is in the charging frequency modulation mode, a preset first rate range is determined as the target rate range, and the target rate is determined from the target rate range; When the sodium-ion battery is in the discharge frequency modulation mode, a target rate range is selected from a plurality of preset rate ranges based on the state data; and the target rate is determined from the target rate range.

6. The method according to claim 5, characterized in that, Based on the status data, a target magnification range is selected from multiple preset magnification ranges, including: Determine whether the individual cell voltage is greater than or equal to a second voltage threshold, whether the state of charge is greater than or equal to a second charge threshold, the second voltage threshold being greater than the first voltage threshold, and the second charge threshold being greater than the first charge threshold; If the single-cell voltage is greater than or equal to the second voltage threshold, and the state of charge is greater than or equal to the second state of charge threshold, then the first rate range is determined as the target rate range; If the single-cell voltage is less than the second voltage threshold and the state of charge is less than the second state of charge threshold, then the second rate range is determined as the target rate range, and the second rate range is a sub-range of the first rate range; Otherwise, the third magnification interval is determined as the target magnification interval, and the third magnification interval is a sub-interval of the second magnification interval.

7. The method according to claim 6, characterized in that, When the sodium-ion battery is in the standby mode, the method further includes: The charge / discharge rate of the sodium-ion battery is determined within the third rate range to adjust the state of charge of the sodium-ion battery to a preset charge range, which is greater than the second charge threshold.

8. The method according to claim 2, characterized in that, The frequency modulation power satisfies the following formula: in, Indicates the frequency modulation power, , , These are the unit voltage coefficient, state-of-charge coefficient, and temperature coefficient determined according to the aforementioned operating mode. For power grid frequency deviation, For the maximum frequency deviation, This is the rated power.

9. A frequency modulation control device based on a sodium-ion battery, characterized in that, include: Battery management system, frequency controller, energy storage converter; The battery management system is used to acquire the status data of the sodium-ion battery, including the temperature, state of charge, and single-cell voltage of the sodium-ion battery. The frequency controller is used to acquire the power grid frequency; The frequency controller and the energy storage converter are used to determine the operating mode of the sodium-ion battery for frequency regulation based on the grid frequency and the state data of the sodium-ion battery. The operating modes include standby, charging frequency regulation, discharging frequency regulation, and operation prohibited. In standby mode, frequency adjustment is not performed. In the charging / discharging frequency adjustment mode, the sodium-ion battery is charged / discharged at a target rate within a preset rate range to adjust the frequency. In the prohibited operation mode, the sodium-ion battery does not participate in frequency adjustment.

10. A frequency modulation system based on a sodium-ion battery, characterized in that, Includes sodium-ion battery packs and frequency modulation control devices for sodium-ion batteries; The sodium-ion battery pack includes multiple sodium-ion batteries; The frequency modulation control device is used to acquire the grid frequency and the status data of the sodium-ion battery, the status data including the temperature, state of charge and single cell voltage of the sodium-ion battery; The frequency control device is also used to determine the operating mode of the sodium-ion battery for frequency regulation based on the grid frequency and the state data of the sodium-ion battery. The operating modes include standby, charging frequency regulation, discharging frequency regulation, and prohibition of operation. In standby mode, the sodium-ion battery does not participate in frequency regulation. In the charging / discharging frequency regulation mode, the sodium-ion battery is charged / discharged at a target rate within a preset rate range for frequency regulation. In the prohibited operation mode, the sodium-ion battery does not charge / discharge.

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