High voltage ride through control method, apparatus and energy storage system for power converter

Abstract

This application discloses a high-voltage ride-through control method, apparatus, and energy storage system for a power converter, belonging to the field of energy storage system technology. The method includes: acquiring the state of charge (SOC) of a battery; determining the battery's state when the SOC meets a first preset condition; acquiring the port voltage of the power converter when the battery is in a first state, the first state representing an uncharged battery state; and adjusting the battery state to a second state when the port voltage meets a second preset condition, the second state representing a charged battery state. The power converter control method provided by this application can protect the power converter by adjusting the battery's uncharged state to a charging state when the battery's SOC is low and the power converter's port voltage abnormally increases, thereby improving the power converter's stability and extending its service life.

Description

Technical Field

[0001] The embodiments of this application relate to the field of energy storage system technology, and in particular to a high voltage ride-through control method, apparatus and energy storage system for a power converter. Background Technology

[0002] Electrochemical energy storage batteries have advantages such as high energy density, high output voltage, long cycle life, and low environmental pollution, and have been widely used in various electronic devices, electric vehicles, and electrochemical energy storage. However, when cells are connected in series to form a battery pack, the voltage of the battery pack fluctuates significantly with changes in state of charge (SOC). When a high voltage ride occurs in the grid / load, if the battery SOC is too low and the battery is in a discharging state, the reactive power will not meet the requirements, and the converter will not be able to operate stably. Summary of the Invention

[0003] The purpose of this application is to provide a high-voltage ride-through control method, device, and energy storage system for a power converter, in order to solve the technical problem in the prior art that when the battery SOC value is too low and it is in a discharging state, if a high voltage ride-through occurs in the power grid / load, the power converter cannot operate stably.

[0004] To address the aforementioned technical problems, embodiments of this application disclose the following technical solutions:

[0005] In a first aspect, a high-voltage ride-through control method for a power converter is provided, wherein one end of the power converter is connected to a battery, and the other end is connected to a power grid or a load; the high-voltage ride-through control method includes:

[0006] Obtain the SOC value of the battery;

[0007] If the SOC value is less than or equal to the SOC threshold, the state of the battery is determined.

[0008] When the battery is in a first state, the port voltage at the other end of the power converter is obtained, where the first state indicates that the battery is not charged.

[0009] When the port voltage is greater than or equal to a voltage threshold, the state of the battery is adjusted to a second state, which represents the charging state of the battery.

[0010] In conjunction with the first aspect, the method for adjusting the state of the battery to the second state includes:

[0011] Adjust the amplitude and phase of the output signal delivered by the power converter to the power grid or load so that the current from the power grid or load flows to the battery.

[0012] In conjunction with the first aspect, the method for adjusting the amplitude and phase of the output signal delivered by the power converter to the power grid or load includes:

[0013] Obtain the amplitude and phase of the grid voltage or load voltage, and calculate the preset output current of the power converter;

[0014] Adjust the feedback control quantity according to the preset output current and real-time current;

[0015] The power converter is adjusted according to the feedback control quantity to adjust the amplitude and phase of the output signal delivered by the power converter to the power grid or load.

[0016] In conjunction with the first aspect, the method for determining the SOC threshold includes:

[0017] The SOC threshold is determined based on m times the battery's full charge capacity;

[0018] Among them, 5% ≤ m ≤ 10%.

[0019] In conjunction with the first aspect, the method for determining the voltage threshold includes:

[0020] The voltage threshold is determined based on n times the rated voltage of the power converter;

[0021] Where 1.1≤n≤1.5.

[0022] In conjunction with the first aspect, the first state includes any one of the following: discharge state, standby state, and quiescent state.

[0023] Secondly, a high-voltage ride-through control device for a power converter is provided, wherein one end of the power converter is connected to a battery, and the other end is connected to a power grid or a load; the high-voltage ride-through control device includes:

[0024] The first acquisition module is configured to acquire the SOC value of the battery;

[0025] The second acquisition module is configured to acquire the state of the battery when the SOC value is less than or equal to the SOC threshold.

[0026] The third acquisition module is configured to acquire the port voltage at the other end of the power converter when the battery is in a first state, wherein the first state represents the battery not being charged.

[0027] A control module is configured to adjust the state of the battery to a second state when the port voltage is greater than or equal to a voltage threshold, the second state representing the charging state of the battery.

[0028] In conjunction with the second aspect, the control module is configured to adjust the amplitude and phase of the output signal delivered by the power converter to the power grid or load so that the current from the power grid or load flows to the battery.

[0029] In conjunction with the second aspect, the control module includes:

[0030] A calculation unit is configured to acquire the amplitude and phase of the grid voltage or load voltage and calculate the preset output current of the power converter;

[0031] An adjustment unit is configured to adjust a feedback control quantity based on the preset output current and the real-time current.

[0032] A control unit configured to adjust the power converter according to a feedback control quantity, thereby adjusting the amplitude and phase of the output signal delivered by the power converter to the power grid or load.

[0033] Thirdly, an energy storage system is provided, the energy storage system including a power converter connected to a battery and a power grid respectively, the power converter being protected by a high voltage ride-through control method for a power converter as described in any one of the first aspects.

[0034] One of the above technical solutions has the following advantages or beneficial effects:

[0035] This application provides a high-voltage ride-through control method for a power converter, comprising: acquiring the state of charge (SOC) of a battery; determining the battery's state when the SOC is less than or equal to a SOC threshold; acquiring the port voltage at the other end of the power converter when the battery is in a first state, the first state representing an uncharged battery state; and adjusting the battery state to a second state when the port voltage is greater than or equal to a voltage threshold, the second state representing a charged battery state. The high-voltage ride-through control method provided by this application can protect the power converter by adjusting the battery's uncharged state to a charging state when the battery's SOC is low and the port voltage of the power converter abnormally increases, thereby improving the stability of the power converter and extending its service life.

[0036] This application also provides a high-voltage ride-through control device for a power converter, comprising: a first acquisition module configured to acquire the SOC value of a battery; a second acquisition module configured to determine the state of the battery when the SOC value is less than or equal to an SOC threshold; a third acquisition module configured to acquire the port voltage at the other end of the power converter when the battery is in a first state, the first state representing an uncharged battery state; and a control module configured to adjust the battery state to a second state when the port voltage is greater than or equal to a voltage threshold, the second state representing a charged battery state. The high-voltage ride-through control device for a power converter provided by this application acquires the SOC value of the battery through the first acquisition module, acquires the port voltage of the power converter through the third acquisition module when the battery SOC is low, and adjusts the battery from an uncharged state to a charging state through the control module when the port voltage abnormally rises, thereby protecting the power converter, improving the stability of the power converter, and extending its service life. Attached Figure Description

[0037] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0038] Figure 1 This is a schematic diagram of the steps of the high voltage ride-through control method for a power converter provided in an embodiment of this application;

[0039] Figure 2 This is a connection diagram of the power converter provided in an embodiment of this application;

[0040] Figure 3 This is a schematic diagram of the relationship between battery SOC and voltage provided in an embodiment of this application;

[0041] Figure 4 This is a schematic diagram of the module connection of the high voltage ride-through control device for the power converter provided in an embodiment of this application. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0043] With the booming development of the electrochemical energy storage market, the safety of electrochemical energy storage batteries themselves is receiving increasing attention. Based on safety and cycle standards, lithium-ion batteries used in energy storage are mostly based on lithium iron phosphate systems. However, the voltage of a single cell is relatively low, making it unsuitable for use in large-scale equipment. To improve energy efficiency, multiple cells are connected in series to form a battery pack, then the battery panels are combined into battery clusters, and finally, multiple battery clusters are connected in parallel for output.

[0044] Those skilled in the art have noted that when multiple cells are connected in series, the voltage of the battery cluster fluctuates significantly with changes in state of charge (SOC). Figure 3 The figure shows the voltage variation of a single battery cell under normal operating voltage, ranging from 2.7V to 3.65V. When the cell is nearing full charge, its voltage is 3.65V; when it is nearing depletion, it is 2.7V, exhibiting significant voltage fluctuations from full charge to full discharge. When cells are connected in series to form a battery pack, the voltage fluctuations between full charge and full discharge are even greater. For example, with 384 cells connected in series, the voltage at full charge can reach 1401.6V, while at full discharge it drops to 1036.8V. Such high voltage fluctuations pose a significant risk of insufficient battery voltage if the battery pack's state of charge (SOC) is too low and it is in a discharging state during grid / load faults, especially high-voltage ride-throughs. This could lead to insufficient reactive power and cause serious damage to the energy storage system.

[0045] The specific implementation methods of this application are illustrated below through examples:

[0046] like Figure 1As shown, this application provides a high-voltage ride-through control method for a power converter, including:

[0047] S1: Get the battery's SOC value.

[0048] Specifically, the State of Charge (SOC) of a battery can be estimated by measuring its open-circuit voltage (OCV). By constructing a curve showing the relationship between battery voltage and SOC and calibrating the relevant range, the SOC can be estimated based on the battery's voltage readings. Alternatively, the SOC can be estimated by establishing a mathematical model of the battery and incorporating parameters such as current, temperature, impedance, and voltage. This method requires modeling the battery's characteristics and behavior and using filtering or optimization algorithms for estimation.

[0049] Understandably, the voltage range is large after batteries are connected in series, which places higher demands on the testing equipment. Therefore, obtaining the SOC value of the battery is used to characterize the voltage state of the battery, which makes it easier to determine the voltage range of the battery. Furthermore, the SOC value makes it easier to determine the state of the battery.

[0050] S2: Determine the state of the battery when the SOC value is less than or equal to the SOC threshold.

[0051] Specifically, the method for determining the SOC threshold includes: obtaining the battery's full charge capacity, and determining the SOC threshold based on m times the full charge capacity; wherein 5% ≤ m ≤ 10%. In some embodiments, m can be any value among 5%, 6%, 7%, 8%, 9%, and 10%, or a range of any two. It is conceivable that the battery voltage fluctuates with the battery SOC value. When the battery SOC value is close to full charge, the battery voltage reaches its maximum, and when the battery SOC value drops to near 0, the battery voltage approaches its minimum. In some cases, when the battery SOC value is close to 5%–10%, the battery voltage is also close to the cutoff voltage. The cutoff voltage refers to the voltage at which the battery stops discharging to prevent over-discharge. Over-discharge can lead to battery damage, capacity loss, and irreversible damage.

[0052] In this embodiment, when the SOC value of the battery is determined to be less than 5% to 10% of the full charge capacity, the battery is determined to meet the first preset condition, and the state of the battery is then determined. It is necessary to confirm whether the battery is in a normal discharge, normal charge, standby, or quiescent state at this time.

[0053] Understandably, by comparing the SOC value with the SOC threshold, the SOC threshold can be determined based on specific needs and application scenarios. By adjusting the range of values ​​for m, the SOC threshold can be flexibly set to meet the requirements of different battery systems.

[0054] S3: When the battery is in the first state, obtain the port voltage at the other end of the power converter. The first state is characterized as the battery not being charged.

[0055] Specifically, the first state includes any one of the following: discharge state, standby state, and quiescent state. It's conceivable that when a battery is in a discharge state, its State of Charge (SOC) continuously decreases, and the corresponding voltage also drops. While the battery is in a standby or quiescent state, although it's in a stable state, each battery still experiences some degree of self-discharge. Therefore, the battery's SOC also decreases slowly, and similarly, the battery voltage decreases slowly. Combining the above, the battery voltage is in an extremely low state and is continuing to decrease. If the port voltage of the power converter experiences an abnormal increase at this time, it will damage the power converter.

[0056] like Figure 2 As shown in this embodiment, the power converter includes a power conversion system (PCS). The PCS is typically connected to the power grid and performs functions such as power conversion, power regulation, grid support, grid interconnection, and energy storage, providing crucial support and control for the operation of the power system and the stability of the power grid. The PCS is usually equipped with grid-side voltage sensors for real-time measurement of the grid voltage. These sensors can be directly connected to the PCS's control system, providing accurate readings of the grid-side voltage. In some cases, the PCS may acquire grid voltage information by communicating with grid monitoring equipment (such as grid monitoring instruments or grid monitoring systems). These devices can provide real-time grid voltage data, which the PCS can obtain by communicating with them.

[0057] Understandably, when the battery's SOC value is low and it is not charging, monitoring the PCS's port voltage allows for timely responses, preventing damage to the PCS from abnormally high port voltages. This protects the PCS, improves its stability, and extends its lifespan.

[0058] S4: When the port voltage is greater than or equal to the voltage threshold, adjust the battery state to the second state, which represents the battery's charging state.

[0059] Specifically, the method for determining the voltage threshold includes: obtaining the rated voltage of the power converter, and determining the voltage threshold based on n times the rated voltage; where 1.1 ≤ n ≤ 1.5. In some embodiments, n can be any value among 1.1, 1.2, 1.3, 1.4, and 1.5, or a range of any two. It is conceivable that the rated voltage of the PCS refers to the nominal voltage specified during system design and manufacturing, representing the voltage range within which the PCS can operate normally and provide rated power. When the voltage of the PCS abnormally increases and exceeds the rated voltage, it may cause excessive current load on the internal electronic components and circuits of the PCS, resulting in overload or overheating, and may also lead to performance degradation, damage, or even malfunction of the PCS. Typically, PCS is equipped with overvoltage protection devices. When the input voltage exceeds the rated voltage, the protection device will trigger and take corresponding measures, such as cutting off the power supply or limiting the current, to protect the PCS and other equipment from overvoltage damage.

[0060] In this embodiment, when the voltage exceeds 1.1 to 1.5 times the rated voltage, the PCS can charge the battery by adjusting its active power and, while meeting reactive power requirements, charge the battery as much as possible. Specifically, battery active power refers to the useful power injected into or absorbed by the battery from the grid, used for the conversion and supply of electrical energy. When the battery active power is positive, it indicates that the battery injects useful work into the grid; when the battery active power is negative, it indicates that the battery absorbs useful work from the grid. Reactive power refers to the power that does not undergo useful work conversion in the power system and is mainly used for the stability and voltage regulation of the power system. Reactive power can be adjusted by changing the voltage amplitude and phase difference to maintain voltage stability and reactive power balance in the power system.

[0061] It is understandable that when the port voltage of the PCS exceeds the rated voltage, it may damage the PCS device. By adjusting the battery's active power to charge it, the voltage load on the PCS device can be reduced, thus protecting it from damage caused by excessive voltage. Furthermore, adjusting the battery's active power to charge it allows the use of electrical energy exceeding the rated voltage to charge the battery. This maximizes the utilization of the electrical energy supplied by the grid, storing excess energy in the battery for later use.

[0062] In this embodiment, the power converter is connected between the battery and the power grid. The method for adjusting the battery's state to a second state includes adjusting the amplitude and phase of the output signal delivered by the power converter to the power grid or load, so that current from the power grid flows to the battery. In this embodiment, the power converter is connected between the battery and the power grid for power conversion and regulation between the power grid and the battery. The power converter includes a converter and an inductor. The converter receives DC power from the battery energy storage system and converts it into AC power to supply AC loads. Simultaneously, the converter can also adjust the voltage and frequency of the output AC power to adapt to different load requirements or the power grid. Precise control of the output voltage and frequency can be achieved by controlling the switching of the converter and adjusting its operating mode. The main function of the inductor is to filter and smooth the output current or voltage. The inductor can reduce ripple and noise in the output current or voltage, making it more stable and pure. Through the current response characteristics of the inductor, high-frequency noise and harmonic components can be filtered out, providing a smoother output signal. Correspondingly, the inductor can also be used to limit and protect the current in the circuit. By utilizing the current characteristics of an inductor, the rate of change of current is limited, preventing excessive or insufficient current and thus protecting circuits and load devices from damage caused by overcurrent.

[0063] In this embodiment, typically, when the battery needs to draw power from the grid, the PCS's converter switches to rectification mode. In rectification mode, the converter converts the AC power from the grid into DC power to charge the battery. At this time, the PCS can regulate the battery's charging speed by controlling the charging power. The charging power can be controlled by adjusting the PCS's output power. When the battery needs charging, the PCS can increase its output power to provide more power and accelerate the charging process. Conversely, when the battery is nearing full charge or does not need charging, the PCS can reduce its output power to avoid overcharging or wasting energy.

[0064] When the battery discharges to the grid or load, the PCS's converter can be switched to inverter mode. In inverter mode, the converter converts the battery's DC power into AC power required by the grid or load. Similarly, the PCS can regulate the rate and amount of battery discharge to the grid by controlling the discharge power. The discharge power can be controlled by adjusting the PCS's output power. When the battery needs to discharge to the grid or load, the PCS can increase its output power to provide more power to the grid. Conversely, when the battery's discharge demand decreases or stops, the PCS can reduce its output power to reduce the amount of power discharged to the grid.

[0065] In this embodiment, the method for adjusting the amplitude and phase of the output signal delivered by the power converter to the power grid or load includes: acquiring the amplitude and phase of the power grid voltage or load voltage, calculating the preset output current of the power converter; adjusting the feedback control quantity based on the preset output current and the real-time current; and adjusting the power converter based on the feedback control quantity to adjust the amplitude and phase of the output signal delivered by the power converter to the power grid or load. Specifically, the amplitude of the power grid voltage refers to the peak value or peak-to-peak value of the voltage, representing the maximum amplitude of the voltage. For AC voltage, the amplitude usually refers to the peak value of the voltage, i.e., the maximum positive or negative value of the voltage waveform. It is conceivable that after acquiring the amplitude and phase of the power grid voltage, the preset output current required by the power converter can be calculated, and the feedback control quantity of the PCS can be obtained based on the difference between the current of the current PCS and the preset output current. Adjusting the amplitude and phase of the output voltage of the PCS based on the feedback control quantity can control the current direction between the power converter and the power grid. When the amplitude of the voltage output by the PCS is greater than the amplitude of the grid voltage, current will flow from the PCS to the grid; conversely, when the amplitude of the voltage output by the PCS is less than the amplitude of the grid voltage, current will flow from the grid to the PCS. Therefore, by controlling the amplitude of the output voltage, the PCS can achieve bidirectional current flow control between itself and the grid.

[0066] Understandably, by changing the amplitude and phase of the output voltage, the PCS can control the direction of the current between the PCS and the power grid, thereby controlling the direction of the battery current, adjusting the battery from an uncharged state to a charging state, thus protecting the PCS, improving its stability, and extending its service life.

[0067] In summary, the power converter protection method provided in this application monitors the port voltage of the PCS when the battery's SOC value is low and it is in an uncharged state. If the PCS port voltage exceeds the rated voltage, it may damage the PCS device. By changing the amplitude and phase of the voltage output to the grid, the PCS can control the current direction between the PCS and the grid, thereby controlling the battery current direction, adjusting the battery from an uncharged state to a charging state. By adjusting the battery's active power to charging, the voltage load on the PCS device can be reduced, thus protecting the PCS device from damage caused by excessive voltage. Furthermore, adjusting the battery's active power to charging allows the use of electrical energy exceeding the rated voltage to charge the battery. This maximizes the utilization of the electrical energy provided by the grid, storing excess energy in the battery for later use, thereby protecting the PCS, improving its stability, and extending its service life.

[0068] like Figure 4As shown in the illustration, this application embodiment also provides a high-voltage ride-through control device for a power converter. One end of the power converter is used to connect to a battery, and the other end is used to connect to the power grid or a load. The high-voltage ride-through control device includes: a first acquisition module configured to acquire the SOC value of the battery; a second acquisition module configured to acquire the state of the battery when the SOC value is less than or equal to an SOC threshold; a third acquisition module configured to acquire the port voltage of the other end of the power converter when the battery is in a first state, the first state representing an uncharged battery state; and a control module configured to adjust the state of the battery to a second state when the port voltage is greater than or equal to a voltage threshold, the second state representing a charged battery state.

[0069] Specifically, the first acquisition module is used to acquire the battery's State of Charge (SOC). Since the battery's SOC is usually mapped to its open-circuit voltage, and the specific value of the SOC is estimated by measuring the open-circuit voltage, the first acquisition module may include a voltage sensor for measuring the open-circuit voltage. Alternatively, the battery's SOC can also be estimated by establishing a relevant mathematical model of the battery and combining it with parameters such as current, temperature, impedance, and voltage. Therefore, the first acquisition module may include an ammeter or current sensor for measuring the battery current; a temperature sensor for acquiring the battery temperature; and a voltage sensor for measuring the battery voltage. The battery's impedance can be obtained through calculations based on voltage and current.

[0070] In this embodiment, the second acquisition module is used to acquire the state of the battery, which includes a normal discharge state, a normal charging state, a standby state, or a static state. It is conceivable that since the parameters exhibited by the battery differ in different states, the specific state of the battery can be determined by measuring changes in battery parameters such as voltage, current, temperature, or impedance. For example, when the battery is in a normal discharge state, the battery voltage gradually decreases over time; while when the battery is in a normal charging state, the battery voltage gradually increases over time; correspondingly, when the battery is in a static or standby state, the battery voltage remains almost constant over time, and this can be determined by the current. In the standby state, the battery still outputs a weak current, while in the static state, there is no current output. Therefore, considering the above, the second acquisition module includes one or more of a voltage sensor, a current sensor, and a temperature sensor.

[0071] In this embodiment, the third acquisition module is used to acquire the port voltage of the power converter. The power converter includes a power conversion system, i.e., a PCS, which is typically equipped with a grid-side voltage sensor for real-time measurement of the grid voltage. These sensors can be directly connected to the PCS control system to provide accurate readings of the grid-side voltage. Therefore, the third acquisition module includes a voltage sensor located in the PCS.

[0072] In this embodiment, the control module includes: a calculation unit configured to acquire the amplitude and phase of the grid voltage or load voltage and calculate a preset output current of the power converter; an adjustment unit configured to adjust a feedback control quantity based on the preset output current and the real-time current; and a control unit configured to adjust the power converter based on the feedback control quantity to adjust the amplitude and phase of the output signal delivered by the power converter to the grid or load. Specifically, the control module controls the current direction between the PCS and the grid, thereby controlling the current direction of the battery, adjusting the battery from an uncharged state to a charging state, thus protecting the PCS, improving its stability, and extending its service life.

[0073] This application also provides an energy storage system, which includes a power converter connected to a battery and a power grid, and the power converter is protected by the method provided in any of the above embodiments.

[0074] The above provides a detailed description of a high-voltage ride-through control method, apparatus, and energy storage system for a power converter provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A high-voltage ride-through control method for a power converter, characterized in that, One end of the power converter is used to connect to the battery, and the other end is used to connect to the power grid or load; the high-voltage ride-through control method includes: Obtain the SOC value of the battery; If the SOC value is less than or equal to the SOC threshold, the state of the battery is determined. When the battery is in a first state, the port voltage at the other end of the power converter is obtained, where the first state indicates that the battery is not charged. When the port voltage is greater than or equal to a voltage threshold, the state of the battery is adjusted to a second state, which represents the charging state of the battery.

2. The high-voltage ride-through control method for a power converter as described in claim 1, characterized in that, The method for adjusting the state of the battery to the second state includes: Adjust the amplitude and phase of the output signal delivered by the power converter to the power grid or load so that the current from the power grid or load flows to the battery.

3. The high-voltage ride-through control method for a power converter as described in claim 2, characterized in that, Methods for adjusting the amplitude and phase of the output signal delivered by the power converter to the power grid or load include: Obtain the amplitude and phase of the grid voltage or load voltage, and calculate the preset output current of the power converter; Adjust the feedback control quantity according to the preset output current and real-time current; The power converter is adjusted according to the feedback control quantity to adjust the amplitude and phase of the output signal delivered by the power converter to the power grid or load.

4. The high-voltage ride-through control method for a power converter as described in claim 1, characterized in that, The method for determining the SOC threshold includes: The SOC threshold is determined based on m times the battery's full charge capacity; Among them, 5% ≤ m ≤ 10%.

5. The high-voltage ride-through control method for a power converter as described in claim 1, characterized in that, The method for determining the voltage threshold includes: The voltage threshold is determined based on n times the rated voltage of the power converter; Where 1.1≤n≤1.

5.

6. The high-voltage ride-through control method for a power converter as described in claim 1, characterized in that, The first state includes any one of the following: discharge state, standby state, and quiescent state.

7. A high-voltage ride-through control device for a power converter, characterized in that, include: One end of the power converter is used to connect to the battery, and the other end is used to connect to the power grid or load; the high voltage ride-through control device includes: The first acquisition module is configured to acquire the SOC value of the battery; The second acquisition module is configured to acquire the state of the battery when the SOC value is less than or equal to the SOC threshold. The third acquisition module is configured to acquire the port voltage at the other end of the power converter when the battery is in a first state, wherein the first state represents the battery not being charged. A control module is configured to adjust the state of the battery to a second state when the port voltage is greater than or equal to a voltage threshold, the second state representing the charging state of the battery.

8. The high-voltage ride-through control device for a power converter as described in claim 7, characterized in that, The control module is configured to adjust the amplitude and phase of the output signal delivered by the power converter to the power grid or load so that the current from the power grid or load flows to the battery.

9. The high-voltage ride-through control device for a power converter as described in claim 8, characterized in that, The control module includes: A calculation unit is configured to acquire the amplitude and phase of the grid voltage or load voltage and calculate the preset output current of the power converter; An adjustment unit is configured to adjust a feedback control quantity based on the preset output current and the real-time current. A control unit configured to adjust the power converter according to a feedback control quantity to adjust the amplitude and phase of the output signal delivered by the power converter to the power grid or load.

10. An energy storage system, characterized in that, The energy storage system includes a power converter, which is connected to both the battery and the power grid. The power converter is protected by the high voltage ride-through control method for the power converter as described in any one of claims 1-6.

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