Energy storage device and battery cluster under-voltage and over-voltage backup protection method and system

Abstract

The application discloses an energy storage device and a battery cluster under-voltage and over-voltage backup protection method and system. The protection method comprises the following steps: reducing the total direct current voltage of the battery cluster by a preset multiple and outputting a first output voltage; obtaining an over-voltage protection threshold and an under-voltage protection threshold of the battery cluster; comparing the first output voltage with the over-voltage protection threshold and the under-voltage protection threshold respectively, and outputting a first pulse voltage and a second pulse voltage; performing an OR gate logic judgment on the first pulse voltage and the second pulse voltage respectively; and controlling a trip circuit of a circuit breaker of the energy storage device to be turned on or turned off according to a judgment result. The protection method can be used as the third-level protection of the under-voltage / over-voltage of the battery cluster, timely discovers and handles the under-voltage / over-voltage problem, reduces the system shutdown and other conditions caused by the battery failure, and improves the reliability and safety of the whole energy storage system.

Description

Technical Field

[0001] This application belongs to the field of energy storage technology, specifically relating to an energy storage device and its battery cluster undervoltage and overvoltage backup protection method and system. Background Technology

[0002] With the large-scale application of renewable energy sources such as solar and wind power, their power generation is characterized by intermittency and fluctuation. Energy storage devices play a prominent role in smoothing power fluctuations and ensuring stable power supply. For example, photovoltaic power plants are equipped with energy storage to store excess electricity and release electricity during wind power off-peak periods. As a key component of energy storage devices, the stable operation of battery clusters is crucial, which has led to the need for overvoltage and undervoltage protection to cope with potential voltage anomalies under complex operating conditions and ensure the reliable operation of the energy storage system.

[0003] Energy storage devices are often integrated by connecting multiple battery clusters in series and parallel to form a large-capacity energy storage system to meet the needs of different scenarios. In such a complex circuit connection, uneven charging and discharging between battery clusters can easily occur. One battery cluster may be overcharged, resulting in overvoltage, or over-discharged, resulting in undervoltage, which in turn affects the stable operation and lifespan of the entire energy storage system. Therefore, an effective overvoltage and undervoltage protection mechanism is needed to coordinate the operation of each battery cluster and prevent abnormalities in individual battery clusters from affecting the overall system.

[0004] From a safety perspective, if overvoltage and undervoltage of battery clusters are not managed in a timely manner, serious safety accidents such as smoke, fire, and explosion may occur, threatening the safety of personnel and the surrounding environment. From an operation and maintenance perspective, reliable overvoltage and undervoltage protection allows maintenance personnel to be aware of the health status of battery clusters in a timely manner, enabling them to take proactive measures such as equalization charging and fault diagnosis, thereby reducing operation and maintenance costs and ensuring the long-term stable operation of energy storage devices. Summary of the Invention

[0005] The purpose of this application is to provide an energy storage device and its battery cluster undervoltage and overvoltage backup protection method and system to improve the safety and reliability of the energy storage device.

[0006] To achieve the above objectives, this application provides a method for undervoltage and overvoltage backup protection of a battery cluster in an energy storage device, the method comprising the following steps:

[0007] The total DC voltage of the battery cluster is reduced by a preset factor, and a first output voltage is output.

[0008] Obtain the overvoltage protection threshold and undervoltage protection threshold of the battery cluster;

[0009] The first output voltage is compared with the overvoltage protection threshold and the undervoltage protection threshold respectively, and the first pulse voltage and the second pulse voltage are output.

[0010] Perform OR gate logic checks on the first pulse voltage and the second pulse voltage respectively;

[0011] Based on the judgment result, the tripping circuit of the circuit breaker of the energy storage device is turned on or off.

[0012] In some embodiments, the step of reducing the total DC voltage of the battery cluster by a preset factor and outputting a first output voltage includes:

[0013] Connect the input terminal of the power isolation sensor to the positive and negative terminals of the battery pack;

[0014] Collect the total DC voltage of the battery cluster;

[0015] The total DC voltage is reduced by a preset factor using a power isolation sensor.

[0016] In some implementations, the steps of obtaining the overvoltage protection threshold and undervoltage protection threshold of the battery cluster include:

[0017] Connect the first and second voltage divider resistors, which are connected in series, between preset voltages;

[0018] The overvoltage protection threshold is the voltage to ground obtained from the second voltage divider resistor.

[0019] Connect the third and fourth voltage divider resistors, which are connected in series, between the preset voltages;

[0020] The voltage to ground obtained from the fourth voltage divider resistor is the undervoltage protection threshold.

[0021] In some implementations, the step of comparing the first output voltage with an overvoltage protection threshold and outputting a first pulse voltage includes:

[0022] If the first output voltage is higher than the overvoltage protection threshold, the first output pulse voltage is the first high-level pulse voltage.

[0023] If the first output voltage is lower than the overvoltage protection threshold, the first output pulse voltage is the first low-level pulse voltage.

[0024] In some implementations, the step of comparing the first output voltage with an undervoltage protection threshold and outputting a second pulse voltage includes:

[0025] If the first output voltage is lower than the undervoltage protection threshold, the second output pulse voltage will be the second high-level pulse voltage.

[0026] If the first output voltage is higher than the undervoltage protection threshold, the second output pulse voltage will be the second low-level pulse voltage.

[0027] In some implementations, the step of performing OR gate logic judgments on the first pulse voltage and the second pulse voltage includes:

[0028] If either the first pulse voltage or the second pulse voltage is a high-level pulse voltage, then the OR gate outputs a high-level pulse voltage.

[0029] If both the first pulse voltage and the second pulse voltage are low-level pulse voltages, then the OR gate outputs a low-level pulse voltage.

[0030] In some implementations, the step of controlling the trip circuit of the energy storage device's circuit breaker to be turned on or off based on the judgment result includes:

[0031] When the OR gate outputs a high-level pulse voltage, the trip circuit of the circuit breaker is turned on, so that the circuit breaker trips.

[0032] When the OR gate outputs a low-level pulse voltage, the trip circuit of the circuit breaker is disconnected, so that the circuit breaker remains in operation.

[0033] A second aspect of this application provides a battery cluster undervoltage and overvoltage backup protection system for an energy storage device, employing the battery cluster undervoltage and overvoltage backup protection method described above. The battery cluster undervoltage and overvoltage backup protection system includes:

[0034] The power isolation sensor has two input terminals, which are connected to the positive and negative terminals of the battery pack, respectively. The output terminal of the power isolation sensor outputs two pulse circuits.

[0035] An OR gate assembly includes two diodes, each of which is disposed on one of two pulse circuits;

[0036] Two voltage comparators are respectively set on two pulse circuits and connected to the input terminals of two diodes;

[0037] The circuit breaker is connected to the output of the OR gate assembly via a trip circuit.

[0038] In some implementations, the battery cluster undervoltage and overvoltage backup protection system also includes a connection between a preset DC voltage:

[0039] The first voltage divider resistor is connected at both ends to the positive and negative terminals of one of the voltage comparators;

[0040] The second voltage divider resistor is connected in series with the first voltage divider resistor;

[0041] The third voltage divider resistor is connected at both ends to the positive and negative terminals of another voltage comparator, respectively.

[0042] The fourth voltage divider resistor is connected in series with the third voltage divider resistor.

[0043] A third aspect of this application provides an energy storage device, including a battery cluster undervoltage and overvoltage backup protection system as described above.

[0044] Through the above technical solutions, the energy storage device and its battery cluster undervoltage and overvoltage backup protection method and system provided by the embodiments of the present invention have the following beneficial effects:

[0045] In the battery cluster undervoltage and overvoltage backup protection method of this application, the total DC voltage of the battery cluster is first reduced by a preset factor and a first output voltage is output; then, the overvoltage protection threshold and undervoltage protection threshold of the battery cluster are obtained; the first output voltage is compared with the overvoltage protection threshold and the undervoltage protection threshold respectively, and a first pulse voltage and a second pulse voltage are output; the first pulse voltage and the second pulse voltage are respectively ORed by logic gate; finally, the tripping circuit of the circuit breaker of the energy storage device is controlled to be turned on or off according to the judgment result. The protection method of this application can be used as the third level of protection for battery cluster undervoltage / overvoltage, which can maintain the voltage of the battery cluster within a reasonable range, reduce system downtime caused by battery failure, and improve the overall reliability and safety of the energy storage system.

[0046] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0047] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without any inventive effort. In the drawings:

[0048] Figure 1 This is a flowchart illustrating the battery cluster undervoltage and overvoltage backup protection method of the energy storage device of this application;

[0049] Figure 2 This is a schematic diagram of the circuit structure of the battery cluster undervoltage and overvoltage backup protection system of the energy storage device of this application.

[0050] Explanation of reference numerals in the attached figures

[0051] 10 battery clusters, 60 relays

[0052] 20 Power isolation sensor 71 First voltage divider resistor

[0053] 30 Voltage comparator 72 Second voltage divider resistor

[0054] 40 OR gate assembly 73 Third voltage divider resistor

[0055] 41 Diode 74 Fourth Voltage Divider Resistor

[0056] 50 circuit breakers Detailed Implementation

[0057] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0058] The following description, with reference to the accompanying drawings, describes an energy storage device and its battery cluster 10 with undervoltage and overvoltage backup protection methods and systems according to this application.

[0059] Different types of batteries (such as lithium-ion batteries and lead-acid batteries) have their own suitable operating voltage ranges. Exceeding these ranges can lead to problems such as electrolyte decomposition and electrode material damage, severely affecting battery life and even causing safety hazards like thermal runaway. Undervoltage, on the other hand, can easily cause sulfation of the battery plates and irreversible damage to the active materials, resulting in reduced battery capacity and deteriorated performance. Therefore, overvoltage and undervoltage protection technologies are needed to precisely control the voltage of the battery cluster 10 based on battery characteristics to maintain good battery performance. Currently, the energy storage device's battery cluster 10 has two levels of undervoltage and overvoltage protection hardware. The first level of protection is the BMS system's own undervoltage / overvoltage protection. When the battery management system (BMS) detects that the total DC voltage of the battery cluster 10 is lower or higher than the set protection threshold, it will promptly cut off the discharge circuit to prevent the battery from continuing to discharge. At the same time, it will send alarm signals to external devices to inform them of the undervoltage situation, and subsequent charging and recovery will be necessary. The second level of protection is the energy storage converter protection. When the PCS detects that the DC bus voltage is lower or higher than the set protection threshold, it will trigger a PCS fault alarm to prevent DC side voltage undervoltage or overvoltage from affecting the grid side voltage.

[0060] In view of this, such as Figure 1 As shown, this application provides a method for undervoltage and overvoltage backup protection of a battery cluster 10 in an energy storage device. This method can serve as a third-level protection for undervoltage / overvoltage of the battery cluster 10, promptly detecting and addressing undervoltage / overvoltage problems, reducing system downtime due to battery failure, and improving the overall reliability of the energy storage system. The method for undervoltage and overvoltage backup protection of the battery cluster 10 includes the following steps:

[0061] S10: Reduce the total DC voltage of battery cluster 10 by a preset factor and output the first output voltage;

[0062] S20: Obtain the overvoltage protection threshold and undervoltage protection threshold of battery cluster 10;

[0063] S30: Compare the first output voltage with the overvoltage protection threshold and the undervoltage protection threshold respectively, and output the first pulse voltage and the second pulse voltage;

[0064] S40: Perform OR gate logic judgment on the first pulse voltage and the second pulse voltage respectively;

[0065] S50: Based on the judgment result, control the tripping circuit of the circuit breaker 50 of the energy storage device to be turned on or off.

[0066] In this embodiment, the total DC voltage of battery cluster 10 is first acquired. Then, the total DC voltage of battery cluster 10 is proportionally reduced by a factor of 100 and output through a power isolation sensor 20. The output voltage of the power isolation sensor 20 is compared with the overvoltage protection threshold and the undervoltage protection threshold respectively through a voltage comparator 30, outputting two pulse voltages. Next, the two output pulse voltages are ORed by an OR gate logic. Finally, the OR gate circuit drives the relay 60, thereby controlling the tripping circuit of the AC molded case circuit breaker 50 at the energy storage device's input line, achieving the purpose of controlling the molded case circuit breaker 50 to trip, thus protecting battery cluster 10 from overvoltage or undervoltage conditions. The technical solution of this application can play a backup protection role when the total positive and total negative voltage of battery cluster 10 is too high or too low, in the event of failure of BMS and PCS undervoltage / overvoltage protection, improving the reliability of system power supply.

[0067] In some embodiments, the step of reducing the total DC voltage of the battery cluster 10 by a preset factor and outputting a first output voltage includes:

[0068] Connect the input terminal of the power isolation sensor 20 to the positive and negative terminals of the battery cluster 10;

[0069] Collect the total DC voltage of battery cluster 10;

[0070] The total DC voltage is reduced by a preset factor using the power isolation sensor 20.

[0071] In this embodiment, the input terminal of the power isolation sensor 20 is connected to the total positive and total negative terminals of the battery cluster 10 to collect the total DC voltage of the battery cluster 10. The collected total DC voltage of the battery cluster 10 is reduced by a factor of 100 and output, for example, an 800V DC voltage is converted to an 8V DC voltage by the power isolation sensor 20. Since the voltage of the battery cluster 10 in the energy storage device is very high, direct operation on it would pose a huge safety risk. This application reduces the total DC voltage of the battery cluster 10, and can provide overvoltage or undervoltage protection for the reduced first output voltage, so as to detect and deal with undervoltage / overvoltage problems in a timely manner.

[0072] For the battery cluster 10 in the industrial and commercial energy storage device, the battery cluster 10 consists of 5 battery packs connected in series. Each battery pack consists of 48 cells connected in series, so the entire battery cluster 10 consists of 48 * 5 = 240 cells connected in series. The nominal voltage of each cell is 3.2V, so the nominal voltage of the battery cluster 10 is 3.2 * 240 = 768V. The overvoltage threshold of each cell is 3.75V, so the overvoltage protection threshold of the battery cluster 10 is 3.75 * 240 = 900V; the undervoltage threshold of each cell is 2.5V, so the undervoltage protection threshold of the battery cluster 10 is 2.5 * 240 = 600V. The selected power isolation sensor 20 can proportionally reduce the voltage of the battery cluster 10 by a factor of 100. For example, 768V is output as 7.68V through the power isolation sensor 20. The corresponding undervoltage protection threshold and overvoltage protection threshold are proportionally reduced by a factor of 100 to 6V and 9V, respectively. The 6V and 9V voltages can be obtained by voltage division through series resistors.

[0073] In some embodiments, the step of obtaining the overvoltage protection threshold and undervoltage protection threshold of the battery cluster 10 includes:

[0074] Connect the first voltage divider resistor 71 and the second voltage divider resistor 72, which are connected in series, between preset voltages;

[0075] The overvoltage protection threshold is the voltage to ground obtained from the second voltage divider resistor 72.

[0076] Connect the third voltage divider resistor 73 and the fourth voltage divider resistor 74, which are connected in series, between the preset voltages;

[0077] The voltage to ground obtained from the fourth voltage divider resistor 74 is the undervoltage protection threshold.

[0078] In this embodiment, the overvoltage protection threshold and undervoltage protection threshold are set using multiple voltage divider resistors. Specifically, the first voltage divider resistor 71 (5kΩ) and the second voltage divider resistor 72 (3kΩ) are connected in series between a DC 24V voltage. The voltage of the second voltage divider resistor 72 to ground is 9V, corresponding to the overvoltage protection threshold. The third voltage divider resistor 73 (3kΩ) and the fourth voltage divider resistor 74 (13kΩ) are connected in series between a DC 24V voltage. The voltage of the fourth voltage divider resistor 74 to ground is 6V, corresponding to the undervoltage protection threshold.

[0079] In some embodiments, the step of comparing the first output voltage with an overvoltage protection threshold and outputting a first pulse voltage includes:

[0080] If the first output voltage is higher than the overvoltage protection threshold, the first output pulse voltage is the first high-level pulse voltage.

[0081] If the first output voltage is lower than the overvoltage protection threshold, the first output pulse voltage is the first low-level pulse voltage.

[0082] Specifically, when overvoltage protection is applied to the battery cluster 10, the output voltage of the power isolation sensor 20 is compared with the overvoltage protection threshold (9V) via the voltage comparator 30. If the output voltage of the power isolation sensor 20 is higher than the overvoltage protection threshold (9V), the first pulse voltage output by the power isolation sensor 20 is a first high-level pulse voltage (24V); otherwise, the first pulse voltage output is a first low-level pulse voltage (0V). In this embodiment, by comparing the first output voltage with the overvoltage protection threshold and controlling the output first pulse voltage, serious safety accidents such as thermal runaway, fire, or even explosion caused by overvoltage are prevented, ensuring the safety of the energy storage device and its surrounding environment. This avoids problems such as plate deformation and active material loss inside the battery due to excessively high voltage, maintaining good battery performance and extending its service life.

[0083] In some embodiments, the step of comparing the first output voltage with an undervoltage protection threshold and outputting a second pulse voltage includes:

[0084] If the first output voltage is lower than the undervoltage protection threshold, the second output pulse voltage will be the second high-level pulse voltage.

[0085] If the first output voltage is higher than the undervoltage protection threshold, the second output pulse voltage will be the second low-level pulse voltage.

[0086] Specifically, when undervoltage protection is applied to the battery cluster 10, the first output voltage of the power isolation sensor 20 is compared with the undervoltage protection threshold (6V) via the voltage comparator 30. If the first output voltage of the power isolation sensor 20 is lower than the undervoltage protection threshold (6V), the second pulse voltage output by the power isolation sensor 20 is a high-level pulse voltage (24V); otherwise, a second low-level pulse voltage (0V) is output. In this embodiment, by comparing the first output voltage with the undervoltage protection threshold and controlling the output first pulse voltage, the battery is prevented from failing to provide sufficient power due to undervoltage, ensuring that the energy storage device can supply power to the external load as needed and guaranteeing the stable operation of the entire energy storage system.

[0087] In some embodiments, the step of performing OR gate logic judgment on the first pulse voltage and the second pulse voltage respectively includes:

[0088] If either the first pulse voltage or the second pulse voltage is a high-level pulse voltage, then the OR gate outputs a high-level pulse voltage.

[0089] If both the first pulse voltage and the second pulse voltage are low-level pulse voltages, then the OR gate outputs a low-level pulse voltage.

[0090] The first pulse voltage and the second pulse voltage are determined by an OR gate logic in the prior art; if the first pulse voltage (or the second pulse voltage) is a high-level pulse voltage, the diode 41 on the corresponding pulse circuit is turned on, and the OR gate outputs a 24V high-level pulse voltage; when both the first pulse voltage and the second pulse voltage are low-level pulse voltages, the diodes 41 on both pulse circuits are reverse-biased and the OR gate outputs a 0V low-level pulse voltage.

[0091] In some embodiments, the step of controlling the tripping circuit of the circuit breaker 50 of the energy storage device to be turned on or off based on the judgment result includes:

[0092] When the OR gate outputs a high-level pulse voltage, the trip circuit of the circuit breaker 50 is turned on, so that the circuit breaker 50 trips.

[0093] When the OR gate outputs a low-level pulse voltage, the trip circuit of the circuit breaker 50 is disconnected, so that the circuit breaker 50 remains in operation.

[0094] In this embodiment, an OR gate circuit drives a relay 60 to control the tripping circuit of the AC molded case circuit breaker 50 at the energy storage device's input line. If the OR gate outputs a 24V high-level pulse voltage (battery cluster 10 is under-voltage or over-voltage), the coil of the intermediate relay 60 conducts, the normally open switch of the relay 60 closes, the tripping circuit of the molded case circuit breaker 50 is connected, and the molded case circuit breaker 50 trips. If the OR gate outputs a 0V low-level pulse voltage (battery cluster 10 is at normal voltage), the coil of the intermediate relay 60 does not conduct, the normally open switch of the intermediate relay 60 opens, the tripping circuit of the molded case circuit breaker 50 is not connected, and the molded case circuit breaker 50 remains in its original state.

[0095] The second aspect of this application provides an undervoltage and overvoltage backup protection system for a battery cluster 10 of an energy storage device, employing the undervoltage and overvoltage backup protection method for the battery cluster 10 as described above. This undervoltage and overvoltage backup protection system includes a power isolation sensor 20, an OR gate assembly 40, two voltage comparators 30, and a circuit breaker 50. The power isolation sensor 20 has two input terminals, which are respectively connected to the positive and negative terminals of the battery cluster 10. The output terminal of the power isolation sensor 20 outputs two pulse circuits. The OR gate assembly 40 includes two diodes 41, which are respectively disposed on the two pulse circuits. The two voltage comparators 30 are respectively disposed on the two pulse circuits and connected to the input terminals of the two diodes 41. The circuit breaker 50 is connected to the output terminal of the OR gate assembly 40 through a tripping circuit.

[0096] When performing overvoltage or undervoltage protection, the protection system of this application adopts the protection method in the above embodiments, which can detect and handle undervoltage / overvoltage problems, reduce system shutdowns caused by battery failures, and improve the overall reliability of the energy storage system; it maintains the voltage of the battery cluster 10 within a reasonable range, ensuring that the entire energy storage system can stably and normally carry out charging and other related work processes.

[0097] like Figure 2 As shown, in some embodiments, the undervoltage and overvoltage backup protection system of the battery cluster 10 further includes a first voltage divider resistor 71 and a second voltage divider resistor 72 connected in series between preset DC voltages, a third voltage divider resistor 73 and a fourth voltage divider resistor 74 connected in series.

[0098] In one embodiment, the first voltage divider resistor 71 and the second voltage divider resistor 72 are connected in series to a 24V DC voltage. The resistance of the first voltage divider resistor 71 is 5kΩ, and the resistance of the second voltage divider resistor 72 is 3kΩ. One end of the first voltage divider resistor 71 is connected to the 24V voltage, and the other end is connected to the second voltage divider resistor 72. One end of the second voltage divider resistor 72 is grounded. The connection between the first voltage divider resistor 71 and the second voltage divider resistor 72 is connected to the negative terminal of the voltage comparator 30. Therefore, the voltage of the second voltage divider resistor 72 to ground is 9V, which corresponds to the overvoltage protection threshold. The third voltage divider resistor 73 and the fourth voltage divider resistor 74 are connected in series to a 24V DC voltage. The resistance of the third voltage divider resistor 73 is 3kΩ, and the resistance of the fourth voltage divider resistor 74 is 13kΩ. One end of the third voltage divider resistor 73 is connected to the voltage terminal of the 24V DC voltage, and the other end is connected to the fourth voltage divider resistor 74. One end of the fourth voltage divider resistor 74 is grounded. The connection point of the third voltage divider resistor 73 and the fourth voltage divider resistor 74 is connected to the positive terminal of the voltage protector. Therefore, the voltage of the fourth voltage divider resistor 74 to ground is 6V, which corresponds to the undervoltage protection threshold.

[0099] A third aspect of this application provides an energy storage device including an undervoltage and overvoltage backup protection system for the battery cluster 10 as described above. Since this energy storage device employs all embodiments of the aforementioned protection system, it possesses all the beneficial effects brought about by the aforementioned protection system, which will not be elaborated upon here.

[0100] In the description of this application, it should be understood that 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 technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0101] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0102] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0103] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for undervoltage and overvoltage backup protection of a battery cluster in an energy storage device, characterized in that, The battery cluster undervoltage and overvoltage backup protection method includes the following steps: The total DC voltage of the battery cluster (10) is reduced by a preset factor and a first output voltage is output; Obtain the overvoltage protection threshold and undervoltage protection threshold of the battery cluster (10); The first output voltage is compared with the overvoltage protection threshold and the undervoltage protection threshold, respectively, and a first pulse voltage and a second pulse voltage are output. Perform OR gate logic judgments on the first pulse voltage and the second pulse voltage respectively; Based on the judgment result, control the tripping circuit of the circuit breaker of the energy storage device to be turned on or off; The step of reducing the total DC voltage of the battery cluster (10) by a preset factor and outputting a first output voltage includes: Connect the input terminal of the power isolation sensor (20) to the positive and negative terminals of the battery cluster (10); Collect the total DC voltage of the battery cluster (10); The total DC voltage is reduced by a preset factor through the power isolation sensor (20); The steps of obtaining the overvoltage protection threshold and undervoltage protection threshold of the battery cluster (10) include: Connect the first voltage divider resistor (71) and the second voltage divider resistor (72) connected in series between the preset voltages; The voltage to ground obtained from the second voltage divider resistor (72) is the overvoltage protection threshold. Connect the third voltage divider resistor (73) and the fourth voltage divider resistor (74) connected in series between the preset voltages; The voltage to ground obtained from the fourth voltage divider resistor (74) is the undervoltage protection threshold. The step of comparing the first output voltage with the overvoltage protection threshold and outputting the first pulse voltage includes: If the first output voltage is higher than the overvoltage protection threshold, then the first output pulse voltage is a first high-level pulse voltage. If the first output voltage is lower than the overvoltage protection threshold, the first output pulse voltage is a first low-level pulse voltage.

2. The battery cluster undervoltage and overvoltage backup protection method according to claim 1, characterized in that, The step of comparing the first output voltage with the undervoltage protection threshold and outputting a second pulse voltage includes: If the first output voltage is lower than the undervoltage protection threshold, the output second pulse voltage is a second high-level pulse voltage. If the first output voltage is higher than the undervoltage protection threshold, the output second pulse voltage is a second low-level pulse voltage.

3. The battery cluster undervoltage and overvoltage backup protection method according to claim 1, characterized in that, The step of performing OR gate logic judgment on the first pulse voltage and the second pulse voltage respectively includes: When either the first pulse voltage or the second pulse voltage is a high-level pulse voltage, the OR gate outputs a high-level pulse voltage. When both the first pulse voltage and the second pulse voltage are low-level pulse voltages, the OR gate outputs a low-level pulse voltage.

4. The battery cluster undervoltage and overvoltage backup protection method according to claim 3, characterized in that, The step of controlling the tripping circuit of the circuit breaker of the energy storage device to be turned on or off based on the judgment result includes: When the OR gate outputs a high-level pulse voltage, the trip circuit of the circuit breaker is controlled to be turned on, so that the circuit breaker trips. When the OR gate outputs a low-level pulse voltage, the trip circuit of the circuit breaker is disconnected, so that the circuit breaker remains in operation.

5. A backup protection system for undervoltage and overvoltage of a battery cluster in an energy storage device, characterized in that, The battery cluster undervoltage and overvoltage backup protection method according to any one of claims 1 to 4, wherein the protection system comprises: A power isolation sensor (20) has two input terminals, which are respectively connected to the positive and negative terminals of the battery cluster (10). The output terminals of the power isolation sensor (20) output two pulse circuits respectively. OR gate assembly (40) includes two diodes (41), which are respectively disposed on two pulse circuits; Two voltage comparators (30) are respectively located on the two pulse circuits and connected to the input terminals of the two diodes (41); The circuit breaker is connected to the output of the OR gate assembly (40) via a tripping circuit.

6. An energy storage device, characterized in that, Includes the battery cluster undervoltage and overvoltage backup protection system as described in claim 5.

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