Energy storage device and battery cluster undervoltage and overvoltage backup protection method and system thereof

Abstract

The invention discloses an energy storage device and a battery cluster undervoltage and overvoltage backup protection method and system thereof. The protection method comprises the following steps: compressing the total direct current of a battery cluster by a preset multiple, and outputting a first output voltage; acquiring an overvoltage protection threshold value and an undervoltage protection threshold value of the battery cluster; comparing the first output voltage with an overvoltage protection threshold value and an undervoltage protection threshold value respectively, and outputting a first pulse voltage and a second pulse voltage; performing OR gate logic judgment on the first pulse voltage and the second pulse voltage; and controlling a tripping loop where a circuit breaker of the energy storage device is located to be connected or disconnected according to a judgment result. The protection method can be used as third-stage protection of under-voltage / over-voltage of the battery cluster, the under-voltage / over-voltage problem can be found and processed in time, the conditions of system shutdown and the like caused by battery faults are reduced, and the overall reliability and safety of the energy storage system are improved.

Description

Technical Field

[0001] The present application belongs to the field of energy storage technology, and specifically relates to an energy storage device and a battery cluster undervoltage and overvoltage backup protection method and system thereof. Background Art

[0002] With the large-scale application of renewable energy such as solar energy and wind energy, their power generation has the characteristics of intermittent and fluctuating. Energy storage devices play an important role in smoothing power fluctuations and ensuring stable power supply. For example, energy storage devices supporting photovoltaic power stations are used to store excess electricity and release electricity when wind power is low. As a key component of energy storage devices, the stable operation of battery clusters is crucial, which has given rise to the need for overvoltage and undervoltage protection to cope with voltage anomalies that may occur under complex working conditions and ensure the reliable operation of energy storage systems.

[0003] Energy storage devices are often integrated with 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, unbalanced charging and discharging between battery clusters is easy to occur. A battery cluster may be overcharged and overvoltage, or over-discharged and undervoltage, which will affect the stable operation and service life of the entire energy storage system. Therefore, an effective overvoltage and undervoltage protection mechanism is needed to coordinate the work of each battery cluster to prevent abnormalities of individual battery clusters from affecting the overall system.

[0004] From a safety perspective, if the overvoltage and undervoltage of the battery cluster are not promptly controlled, 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, with reliable overvoltage and undervoltage protection, it is convenient for operation and maintenance personnel to know the health status of the battery cluster in a timely manner, take measures such as balanced charging and troubleshooting in advance, reduce operation and maintenance costs, and ensure the long-term stable operation of the energy storage device. Summary of the invention

[0005] The purpose of the present application is to provide an energy storage device and a battery cluster undervoltage and overvoltage backup protection method and system thereof, so as to improve the safety and reliability of the energy storage device.

[0006] In order to achieve the above-mentioned object, the present application provides, on one hand, a battery cluster undervoltage and overvoltage backup protection method for an energy storage device, the battery cluster undervoltage and overvoltage backup protection method comprising the steps of:

[0007] reducing the total DC voltage of the battery cluster by a preset multiple and outputting a first output voltage;

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

[0009] Compare the first output voltage with the overvoltage protection threshold and the undervoltage protection threshold respectively, and output a first pulse voltage and a second pulse voltage;

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

[0011] The tripping circuit where the circuit breaker of the energy storage device is located is controlled to be turned on or off according to the judgment result.

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

[0013] Connect the input end of the power isolation sensor to the positive and negative electrodes of the battery cluster;

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

[0015] The total DC voltage is reduced by a preset multiple through the power isolation sensor.

[0016] In some embodiments, the step of obtaining an overvoltage protection threshold and an undervoltage protection threshold of the battery cluster includes:

[0017] Connecting a first voltage-dividing resistor and a second voltage-dividing resistor in series between a preset voltage;

[0018] The voltage of the second voltage-dividing resistor to ground is the overvoltage protection threshold.

[0019] Connecting the third voltage-dividing resistor and the fourth voltage-dividing resistor connected in series between the preset voltages;

[0020] The voltage of the fourth voltage-dividing resistor to ground is obtained as the under-voltage protection threshold.

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

[0022] When the first output voltage is higher than the overvoltage protection threshold, the output first pulse voltage is a first high-level pulse voltage;

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

[0024] In some embodiments, the step of comparing the first output voltage with the under-voltage protection threshold and outputting the second pulse voltage comprises:

[0025] When the first output voltage is lower than the undervoltage protection threshold, the output second pulse voltage is a second high level pulse voltage;

[0026] When the first output voltage is higher than the under-voltage protection threshold, the output second pulse voltage is a second low-level pulse voltage.

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

[0028] When the first pulse voltage or the second pulse voltage is a high-level pulse voltage, the OR gate outputs a high-level pulse voltage;

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

[0030] In some embodiments, the step of controlling the tripping circuit of the circuit breaker of the energy storage device to be turned on or off according to the judgment result includes:

[0031] When the OR gate outputs a high-level pulse voltage, the tripping circuit where the circuit breaker is located is controlled to be turned on, so that the circuit breaker trips;

[0032] When the OR gate outputs a low-level pulse voltage, the tripping circuit where the circuit breaker is located is controlled to be disconnected, so that the circuit breaker remains in a working state.

[0033] A second aspect of the present application provides a battery cluster undervoltage and overvoltage backup protection system for an energy storage device, which adopts the battery cluster undervoltage and overvoltage backup protection method as described above. The battery cluster undervoltage and overvoltage backup protection system comprises:

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

[0035] The OR gate component includes two diodes, and the two diodes are respectively arranged on two pulse circuits;

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

[0037] The circuit breaker is connected to the output end of the OR gate component through a tripping circuit.

[0038] In some embodiments, the battery cluster undervoltage and overvoltage backup protection system further includes:

[0039] A first voltage-dividing resistor, two ends of which are respectively connected to the positive and negative electrodes of one of the voltage comparators;

[0040] A second voltage-dividing resistor, the second voltage-dividing resistor and the first voltage-dividing resistor are connected in series;

[0041] A third voltage-dividing resistor, two ends of which are respectively connected to the positive and negative electrodes of another voltage comparator;

[0042] A fourth voltage-dividing resistor is connected in series with the third voltage-dividing resistor.

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

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

[0045] In the battery cluster undervoltage and overvoltage backup protection method of the present application, firstly, the total DC voltage of the battery cluster is reduced by a preset multiple 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; an OR gate logic judgment is performed on the first pulse voltage and the second pulse voltage, respectively; finally, the tripping circuit where the circuit breaker of the energy storage device is located is controlled to be turned on or off according to the judgment result. The protection method of the present application can be used as the third-level protection of undervoltage / overvoltage of the battery cluster, which can maintain the voltage of the battery cluster in a reasonable range, reduce system shutdowns caused by battery failures, and improve the overall reliability and safety of the energy storage system.

[0046] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. In the drawings:

[0048] Figure 1 A flow chart of a battery cluster undervoltage and overvoltage backup protection method for an energy storage device of the present 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 the present application.

[0050] Description of Reference Numerals

[0051] 10 Battery Cluster 60 Relay

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

[0053] 30 Voltage comparator 72 Second voltage dividing resistor

[0054] 40 OR gate component 73 third voltage divider resistor

[0055] 41 diode 74 fourth voltage dividing resistor

[0056] 50 Circuit Breaker DETAILED DESCRIPTION

[0057] The specific implementation of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present application, and is not used to limit the present application.

[0058] The energy storage device and the undervoltage and overvoltage backup protection method and system of the battery cluster 10 according to the present application are described below with reference to the accompanying drawings.

[0059] Since different types of batteries (such as lithium-ion batteries, lead-acid batteries, etc.) have their own suitable operating voltage ranges, if the voltage exceeds this range, it may cause problems such as decomposition of the electrolyte inside the battery and damage to the electrode material structure, which seriously affects the battery life and even leads to safety hazards such as thermal runaway; undervoltage is easy to cause battery plate sulfidation and irreversible damage to the active material, which will reduce the battery capacity and performance. Therefore, it is necessary to rely on overvoltage and undervoltage protection technology to accurately control the voltage of the battery cluster 10 according to the battery characteristics to maintain good battery performance. At present, the energy storage device battery cluster 10 has two-level undervoltage and overvoltage protection hardware. The first level of protection is the undervoltage / overvoltage protection of the BMS system itself. When the battery management system (BMS) detects that the total DC voltage of the battery cluster 10 is lower than or higher than the set protection threshold, it will cut off the discharge circuit in time to prevent the battery from continuing to discharge, and send an alarm signal to the external device to inform the undervoltage situation, and then reasonable charging recovery is required. The second level of protection is the energy storage converter protection. When the PCS detects that the DC bus voltage is lower than or higher than the set protection threshold, it will trigger the PCS fault alarm to prevent the DC side voltage from being undervoltage or overvoltage and affecting the grid side voltage.

[0060] In view of this, if Figure 1 As shown, the present application provides a backup protection method for undervoltage and overvoltage of a battery cluster 10 of an energy storage device, which can be used as a third-level protection for undervoltage / overvoltage of the battery cluster 10, timely discover and handle undervoltage / overvoltage problems, reduce system downtime caused by battery failure, and improve the overall reliability of the energy storage system. The backup protection method for undervoltage and overvoltage of the battery cluster 10 includes the following steps:

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

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

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

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

[0065] S50: Controlling the tripping circuit where the circuit breaker 50 of the energy storage device is located to be turned on or off according to the judgment result.

[0066] In this embodiment, the total DC voltage of the battery cluster 10 is first obtained, and then the total DC voltage of the battery cluster 10 collected is proportionally reduced by 100 times and output through the power isolation sensor 20, and the output voltage of the power isolation sensor 20 is compared with the overvoltage protection threshold and the undervoltage protection threshold through the voltage comparator 30, and two pulse voltages are output; secondly, the output two pulse voltages are subjected to OR gate logic judgment; finally, the relay 60 is driven by the OR gate circuit to control the tripping circuit of the AC molded case circuit breaker 50 at the incoming line of the energy storage device, so as to achieve the purpose of controlling the tripping of the molded case circuit breaker 50, thereby protecting the battery cluster 10 from overvoltage or undervoltage conditions. The technical solution of the present application can play a role of backup protection when the total positive and total negative voltages of the battery cluster 10 are too high or too low, and can improve the reliability of system power supply when the undervoltage / overvoltage protection of the BMS and PCS fails.

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

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

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

[0070] The total DC voltage is reduced by a preset multiple through the electrical isolation sensor 20 .

[0071] In this embodiment, the input terminal of the power isolation sensor 20 is connected to the total positive and negative terminals of the battery cluster 10 to collect the total DC voltage of the battery cluster 10, and the collected total DC voltage of the battery cluster 10 is proportionally reduced by 100 times and output, for example, 800V DC voltage is converted into 8V DC voltage through the power isolation sensor 20. Since the voltage of the battery cluster 10 in the energy storage device is very large, there will be huge safety risks if it is directly operated. In this application, by reducing the total DC voltage of the battery cluster 10, overvoltage or undervoltage protection can be performed for the reduced first output voltage, so as to timely discover and handle undervoltage / overvoltage problems.

[0072] For the battery cluster 10 of the industrial and commercial energy storage device, the battery cluster 10 is composed of 5 battery PACKs connected in series, and a single battery PACK is composed of 48 batteries connected in series. Then the entire battery cluster 10 is composed of 48*5=240 batteries connected in series, and the nominal voltage of the battery cell is 3.2V, and the corresponding nominal voltage of the battery cluster 10 is 3.2*240=768V. The battery cell overvoltage threshold is 3.75V, and the corresponding battery cluster 10 overvoltage protection threshold is 3.75*240=900V; the battery cell undervoltage threshold is 2.5V, and the corresponding battery cluster 10 undervoltage protection threshold is 2.5*240=600V. The selected power isolation sensor 20 can reduce the voltage of the battery cluster 10 by 100 times. For example, 768V is output as 7.68V through the power isolation sensor 20, and the corresponding undervoltage protection threshold and overvoltage protection threshold are reduced by 100 times to 6V and 9V, and the 6V and 9V voltages can be obtained by series resistor voltage division.

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

[0074] Connect the first voltage-dividing resistor 71 and the second voltage-dividing resistor 72 in series between the preset voltages;

[0075] The voltage of the second voltage-dividing resistor 72 to ground is obtained as the overvoltage protection threshold.

[0076] Connect the third voltage-dividing resistor 73 and the fourth voltage-dividing resistor 74 connected in series between the preset voltages;

[0077] The voltage of the fourth voltage-dividing resistor 74 to ground is obtained as the under-voltage protection threshold.

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

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

[0080] When the first output voltage is higher than the overvoltage protection threshold, the output first pulse voltage is a first high-level pulse voltage;

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

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

[0083] In some embodiments, the step of comparing the first output voltage with the under-voltage protection threshold and outputting the second pulse voltage comprises:

[0084] When the first output voltage is lower than the undervoltage protection threshold, the output second pulse voltage is a second high level pulse voltage;

[0085] When the first output voltage is higher than the under-voltage protection threshold, the output second pulse voltage is a second low-level pulse voltage.

[0086] Specifically, when the battery cluster 10 is under-voltage protected, the first output voltage of the power isolation sensor 20 is compared with the under-voltage protection threshold (6V) through the voltage comparator 30. If the first output voltage of the power isolation sensor 20 is lower than the under-voltage protection threshold (6V), the second pulse voltage output by the power isolation sensor 20 is a high-level pulse voltage (24V), otherwise the second low-level pulse voltage (0V) is output. In this embodiment, the first output voltage is compared with the under-voltage protection threshold, and the output first pulse voltage is controlled to avoid the battery from being unable to provide sufficient power due to under-voltage, ensure that the energy storage device can supply power to the external load as required, and ensure 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] When the first pulse voltage or the second pulse voltage is a high-level pulse voltage, the OR gate outputs a high-level pulse voltage;

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

[0090] The first pulse voltage and the second pulse voltage are judged by the 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 controlled to be turned on, and the OR gate outputs a 24V high-level pulse voltage; when the first pulse voltage and the second pulse voltage are both low-level pulse voltages, the diodes 41 on the two pulse circuits are reversely cut off, and the OR gate outputs a 0V low-level pulse voltage.

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

[0092] When the OR gate outputs a high-level pulse voltage, the tripping circuit where the circuit breaker 50 is located is controlled to be turned on, so that the circuit breaker 50 is tripped;

[0093] When the OR gate outputs a low-level pulse voltage, the tripping circuit where the circuit breaker 50 is located is controlled to be disconnected, so that the circuit breaker 50 remains in the working state.

[0094] In this embodiment, the tripping circuit of the AC molded case circuit breaker 50 at the incoming line of the energy storage device is controlled by driving the relay 60 through an OR gate circuit. If the OR gate outputs a 24V high-level pulse voltage (the battery cluster 10 is undervoltage or overvoltage), the coil of the intermediate relay 60 is turned on, the normally open switch of the relay 60 is closed, the tripping circuit where the molded case circuit breaker 50 is located is turned on, and the molded case circuit breaker 50 is tripped. If the OR gate outputs a 0V low-level pulse voltage (normal voltage of the battery cluster 10), the coil of the intermediate relay 60 is not turned on, the normally open switch of the intermediate relay 60 is opened, the tripping circuit of the molded case circuit breaker 50 is not turned on, and the molded case circuit breaker 50 maintains its original state.

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

[0096] The protection system of the present application adopts the protection method in the above embodiment when performing overvoltage or undervoltage protection, 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; maintain the voltage of the battery cluster 10 within a reasonable range, and ensure that the entire energy storage system can stably and normally perform related work processes such as charging.

[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-dividing resistor 71 and a second voltage-dividing resistor 72 connected in series between the preset DC voltages, and a third voltage-dividing resistor 73 and a fourth voltage-dividing resistor 74 connected in series.

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

[0099] The third aspect of the present application provides an energy storage device, including the above-mentioned undervoltage and overvoltage backup protection system for the battery cluster 10. Since the energy storage device adopts all embodiments of the above-mentioned protection system, it has all the beneficial effects brought by the above-mentioned protection system, which will not be described in detail here.

[0100] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0101] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0102] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0103] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A battery cluster undervoltage and overvoltage backup protection method for an energy storage device, characterized in that: The battery cluster undervoltage and overvoltage backup protection method comprises the following steps: Reducing the total DC voltage of the battery cluster (10) by a preset multiple and outputting a first output voltage; Obtaining an overvoltage protection threshold and an undervoltage protection threshold of the battery cluster (10); Compare the first output voltage with the overvoltage protection threshold and the undervoltage protection threshold respectively, and output a first pulse voltage and a second pulse voltage; Performing OR gate logic judgment on the first pulse voltage and the second pulse voltage respectively; 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.

2. The battery cluster undervoltage and overvoltage backup protection method according to claim 1, characterized in that: The step of reducing the total DC voltage of the battery cluster (10) by a preset multiple and outputting a first output voltage comprises: Connecting the input end of the power isolation sensor (20) to the positive and negative electrodes of the battery cluster (10); collecting the total DC voltage of the battery cluster (10); The total DC voltage is reduced by a preset multiple via the electrical quantity isolation sensor (20).

3. The battery cluster undervoltage and overvoltage backup protection method according to claim 1, characterized in that: The step of obtaining the overvoltage protection threshold and the undervoltage protection threshold of the battery cluster (10) comprises: Connecting a first voltage-dividing resistor (71) and a second voltage-dividing resistor (72) connected in series between a preset voltage; The voltage of the second voltage-dividing resistor (72) to ground is obtained as the overvoltage protection threshold. Connecting a third voltage-dividing resistor (73) and a fourth voltage-dividing resistor (74) connected in series between a preset voltage; The voltage of the fourth voltage-dividing resistor (74) to ground is obtained as the under-voltage protection threshold.

4. 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 overvoltage protection threshold and outputting a first pulse voltage comprises: When the first output voltage is higher than the overvoltage protection threshold, the output first pulse voltage is a first high-level pulse voltage; When the first output voltage is lower than the overvoltage protection threshold, the output first pulse voltage is a first low-level pulse voltage.

5. 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 comprises: When the first output voltage is lower than the under-voltage protection threshold, the output second pulse voltage is a second high-level pulse voltage; When the first output voltage is higher than the under-voltage protection threshold, the output second pulse voltage is a second low-level pulse voltage.

6. 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 comprises: When 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 the first pulse voltage and the second pulse voltage are both low-level pulse voltages, the OR gate outputs a low-level pulse voltage.

7. The battery cluster undervoltage and overvoltage backup protection method according to claim 6, 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 according to the judgment result comprises: When the OR gate outputs a high-level pulse voltage, the tripping circuit where the circuit breaker is located is controlled to be turned on, so that the circuit breaker trips; When the OR gate outputs a low-level pulse voltage, the tripping circuit where the circuit breaker is located is controlled to be disconnected, so that the circuit breaker remains in a working state.

8. A battery cluster undervoltage and overvoltage backup protection system for an energy storage device, characterized in that: According to any one of claims 1 to 7, the battery cluster undervoltage and overvoltage backup protection method is adopted, and the protection system comprises: A power isolation sensor (20), the power isolation sensor (20) having two input ends, the two input ends being respectively connected to the positive terminal and the negative terminal of the battery cluster (10), and the output end of the power isolation sensor (20) respectively outputs two pulse circuits; An OR gate component (40) comprises two diodes (41), wherein the two diodes (41) are respectively arranged on the two pulse circuits; Two voltage comparators (30), respectively disposed on the two pulse circuits and connected to the input ends of the two diodes (41); A circuit breaker is connected to the output end of the OR gate component (40) via a tripping circuit.

9. The battery cluster undervoltage and overvoltage backup protection system according to claim 8, characterized in that: The battery cluster undervoltage and overvoltage backup protection system also includes: A first voltage-dividing resistor (71), two ends of which are respectively connected to the positive and negative electrodes of one of the voltage comparators (30); A second voltage-dividing resistor (72), wherein the second voltage-dividing resistor (72) and the first voltage-dividing resistor (71) are connected in series; A third voltage-dividing resistor (73), two ends of which are respectively connected to the positive and negative electrodes of another voltage comparator (30); A fourth voltage-dividing resistor (74), wherein the fourth voltage-dividing resistor (74) and the third voltage-dividing resistor (73) are connected in series.

10. An energy storage device, characterized in that: It comprises the battery cluster undervoltage and overvoltage backup protection system according to claim 8 or 9.

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