A protection circuit and energy storage high-voltage box

Abstract

The utility model discloses a protection circuit and energy storage high voltage box, fuse is set between battery group and circuit breaker, has saved the space of PCS side in energy storage high voltage box on structure, and when the output current of battery group appears the substantial increase, such as output current is greater than first preset current threshold value, current first passes through fuse, and fuse immediately fuses, to the protection of rear circuit breaker and PCS, and when the output current of battery group appears the small amplitude increase, namely output current is between second preset current threshold value and first preset current threshold value, need not fuse to fuse protection, but is by circuit breaker and is closed off protection, and circuit breaker still can close after the output current of battery group is normal, has reduced the consumption cost of fuse. Fuse protects the substantial increase of overcurrent, and circuit breaker protects the small amplitude overcurrent, avoids the device burnout in circuit, saves the consumption cost of device simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, and in particular to a protection circuit and an energy storage high-voltage box. Background Technology

[0002] The high-voltage storage box is an important component of the energy storage battery system. It contains various electronic devices, such as the battery management system, fuses, and disconnect switches. The energy storage battery system also includes battery packs and a PCS (Power Conversion System). The first terminal of the disconnect switch is connected to the output terminal of the battery pack, the second terminal of the disconnect switch is connected to the first terminal of the fuse, the second terminal of the fuse is connected to the first terminal of the PCS, and the second terminal of the PCS is connected to the power grid. Under normal conditions, the disconnect switch remains closed.

[0003] The PCS has two operating modes: inverter and rectifier. When the PCS operates in inverter mode, the battery pack outputs DC power, which passes through a disconnect switch and a fuse to the PCS. The PCS then inverts the DC power into AC power for grid connection. When the PCS operates in rectifier mode, it rectifies the AC power from the grid side into DC power, which then passes through a fuse and a disconnect switch to the battery pack, thereby charging the battery pack.

[0004] When the battery pack outputs DC power, if a fault occurs inside the battery pack and the output current of the battery pack is too large, the fuse will blow to protect the PCS and other components in the circuit. However, since the fuse is located between the disconnect switch and the PCS, the large current output by the battery pack first passes through the disconnect switch before reaching the fuse, and the disconnect switch is still at risk of being burned out. Utility Model Content

[0005] The purpose of this invention is to provide a protection circuit and an energy storage high-voltage box. The fuse is positioned between the battery pack and the circuit breaker, structurally saving space on the PCS side of the energy storage high-voltage box. Furthermore, when the battery pack's output current increases significantly, such as exceeding a first preset current threshold, the current first passes through the fuse, which immediately blows, protecting the subsequent circuit breaker and PCS. Conversely, when the battery pack's output current increases only slightly, i.e., between the second and first preset current thresholds, the fuse is not required for protection; instead, the circuit breaker provides shut-off protection. The circuit breaker can close again once the battery pack's output current returns to normal, reducing the cost of fuses. The fuse protects against large overcurrents, while the circuit breaker protects against small overcurrents, preventing component burnout and saving on component costs.

[0006] To solve the above-mentioned technical problems, this utility model provides a protection circuit, including a circuit breaker and a fuse;

[0007] The first end of the fuse is connected to the output end of the battery pack, and the second end is connected to the first end of the circuit breaker, for use to melt when the output current of the battery pack is greater than a first preset current threshold.

[0008] The second terminal of the circuit breaker is connected to the first terminal of the PCS and is used to turn off the circuit when the output current of the battery pack is greater than the second preset current threshold and not greater than the first preset current threshold; the first preset current threshold is greater than the second preset current threshold.

[0009] Preferably, the fuse includes a first fuse and a second fuse;

[0010] The first end of the first fuse is connected to the positive output terminal of the battery pack, and the second end is connected to the first positive terminal of the circuit breaker.

[0011] The first end of the second fuse is connected to the negative output terminal of the battery pack, and the second end is connected to the first negative terminal of the circuit breaker.

[0012] The second positive terminal of the circuit breaker is connected to the first positive terminal of the PCS, and the second negative terminal of the circuit breaker is connected to the first negative terminal of the PCS.

[0013] Preferably, it also includes a current acquisition transformer, and the circuit breaker includes a trip unit, a first contact of the circuit breaker, and a second contact of the circuit breaker;

[0014] The primary coil of the current acquisition transformer is wound around the wire at the positive output terminal of the battery pack or around the wire at the negative output terminal of the battery pack, in order to sense the output current of the battery pack.

[0015] The secondary coil of the current acquisition transformer is connected to the input terminal of the trip unit, and is used to transmit the current on the primary coil of the current acquisition transformer to the trip unit;

[0016] The output terminal of the trip unit is connected to the control terminal of the first contact and the control terminal of the second contact of the circuit breaker, and is used to control the first contact and the second contact of the circuit breaker to turn off when the output current of the battery pack is greater than the second preset current threshold and not greater than the first preset current threshold.

[0017] The first end of the first contact of the circuit breaker is connected to the second end of the first fuse, and the second end is connected to the first positive end of the PCS.

[0018] The first end of the second contact of the circuit breaker is connected to the second end of the second fuse, and the second end is connected to the first negative end of the PCS.

[0019] Preferably, it also includes a contactor module and a control circuit;

[0020] The first positive terminal of the contactor module is connected to the second terminal of the first contact of the circuit breaker, the first negative terminal of the contactor module is connected to the second terminal of the second contact of the circuit breaker, the second positive terminal of the contactor module is connected to the first positive terminal of the PCS, and the second negative terminal of the contactor module is connected to the first negative terminal of the PCS.

[0021] The input terminal of the control circuit is connected to the circuit breaker, and the output terminal of the control circuit is connected to the control terminal of the contactor module, for controlling the contactor module to turn off when a circuit off command is received, or when the circuit breaker is detected to be off, or when the fuse is detected to be blown.

[0022] Preferably, the contactor module includes a first contactor and a second contactor;

[0023] The first end of the first contactor is connected to the second end of the first contact of the circuit breaker, the second end of the first contactor is connected to the first positive end of the PCS, and the control end of the first contactor is connected to the output end of the control circuit.

[0024] The first end of the second contactor is connected to the second end of the second contact of the circuit breaker, the second end of the second contactor is connected to the first negative terminal of the PCS, and the control end of the second contactor is connected to the output end of the control circuit.

[0025] Preferably, the battery pack is connected to the fuse, the fuse to the circuit breaker, and the circuit breaker to the PCS via copper busbars.

[0026] Preferably, it also includes a current acquisition module and an alarm module;

[0027] The input terminal of the current acquisition module is connected to the output terminal of the battery pack, and is used to acquire the output current of the battery pack;

[0028] The input terminal of the alarm module is connected to the output terminal of the current acquisition module, and is used to output a first alarm signal when the output current of the battery pack is greater than the first preset current threshold, and to output a second alarm signal when the output current of the battery pack is greater than the second preset current threshold but not greater than the first preset current threshold.

[0029] Preferably, the alarm module includes an audible alarm circuit;

[0030] The sound alarm circuit is used to emit a sound wave of a first frequency when the output current of the battery pack is greater than the first preset current threshold, and to emit a sound wave of a second frequency when the output current of the battery pack is greater than the second preset current threshold but not greater than the first preset current threshold; the first frequency is greater than the second frequency.

[0031] Preferably, the alarm module includes a light alarm circuit;

[0032] The light alarm circuit is used to illuminate the light in a first light mode when the output current of the battery pack is greater than the first preset current threshold, and to illuminate the light in a second light mode when the output current of the battery pack is greater than the second preset current threshold but not greater than the first preset current threshold; the brightness of the first light mode is greater than the brightness of the second light mode, and / or the color temperature of the first light mode is lower than the color temperature of the second light mode.

[0033] To solve the above-mentioned technical problems, this utility model provides an energy storage high-voltage box, including the protection circuit as described above;

[0034] The fuse in the protection circuit is located on the side of the energy storage high-voltage box closer to the battery pack, and the contactor module in the protection circuit is located on the side of the energy storage high-voltage box closer to the PCS.

[0035] This application provides a protection circuit and an energy storage high-voltage box. The fuse is positioned between the battery pack and the circuit breaker, structurally saving space on the PCS side of the energy storage high-voltage box. Furthermore, when the battery pack's output current increases significantly, such as exceeding a first preset current threshold, the current first passes through the fuse, which immediately blows, protecting the downstream circuit breaker and PCS. Conversely, when the battery pack's output current increases only slightly, i.e., between the second and first preset current thresholds, the fuse is not required for protection; instead, the circuit breaker provides shut-off protection. The circuit breaker can close again once the battery pack's output current returns to normal, reducing the cost of fuses. The fuse protects against large overcurrents, while the circuit breaker protects against small overcurrents, preventing component burnout and saving on component costs. Attached Figure Description

[0036] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A schematic diagram of the structure of a protection circuit provided by this utility model;

[0038] Figure 2 A specific structural diagram of a protection circuit provided by this utility model;

[0039] Figure 3 A schematic diagram of an energy storage high-voltage box provided by this utility model. Detailed Implementation

[0040] The core of this invention is to provide a protection circuit and an energy storage high-voltage box. The fuse is positioned between the battery pack and the circuit breaker, structurally saving space on the PCS side of the energy storage high-voltage box. Furthermore, when the battery pack's output current increases significantly, such as exceeding a first preset current threshold, the current first passes through the fuse, which immediately blows, protecting the subsequent circuit breaker and PCS. Conversely, when the battery pack's output current increases only slightly, i.e., between the second and first preset current thresholds, the fuse is not needed for protection; instead, the circuit breaker provides shut-off protection. The circuit breaker can close again once the battery pack's output current returns to normal, reducing the cost of fuse consumption. The fuse protects against large overcurrents, while the circuit breaker protects against small overcurrents, preventing component burnout and saving on component costs.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0042] Please refer to Figure 1 , Figure 1 A schematic diagram of a protection circuit provided by this utility model includes a circuit breaker 2 and a fuse 1;

[0043] The first end of the fuse 1 is connected to the output end of the battery pack, and the second end is connected to the first end of the circuit breaker 2, and is used to blow the fuse when the output current of the battery pack is greater than a first preset current threshold.

[0044] The second terminal of the circuit breaker 2 is connected to the first terminal of the PCS and is used to turn off when the output current of the battery pack is greater than the second preset current threshold and not greater than the first preset current threshold; the first preset current threshold is greater than the second preset current threshold.

[0045] The high-voltage storage box in an energy storage battery system typically includes a battery management system, fuses, and disconnect switches. The battery management system monitors and manages the battery pack's status, such as monitoring parameters like output current and temperature. The disconnect switches and fuses connect the battery pack and the power supply system (PCS). Under normal operating conditions, the disconnect switches remain closed to isolate the circuit between the battery pack and the PCS. The fuses are located between the disconnect switches and the PCS. When the battery pack's output current is too high, the fuses blow the circuit for protection. However, because the large current from the battery pack passes through the disconnect switches first, there is a possibility that the disconnect switches may burn out before the fuse blows.

[0046] To address the aforementioned technical issues, in this embodiment, fuse 1 is directly connected to the battery pack, while circuit breaker 2 is connected between fuse 1 and the PCS. Circuit breaker 2 is a switch that can shut off for protection when the battery pack's output current exceeds a second preset current threshold. Based on this, the battery pack's output current first passes through fuse 1 and then circuit breaker 2. When the battery pack's output current is less than the second preset current threshold, it can be determined that the battery pack's output current is normal. Therefore, fuse 1 does not blow, and circuit breaker 2 does not shut off. The PCS can then invert the DC power output from the battery pack into AC power and connect it to the grid. However, when the battery pack's output current exceeds the second preset current threshold but is less than the first preset current threshold, since the fuse 1's blowing current (i.e., the first preset current threshold) has not been reached, fuse 1 will not blow. The battery pack's output current is transmitted through fuse 1 to circuit breaker 2, which shuts off for protection to prevent the battery pack's output current from affecting the normal operation of the devices inside the PCS. Since circuit breaker 2 is reusable... The circuit breaker 2 can be reclosed after the battery pack's output current returns to normal, i.e., when the battery pack's output current is no greater than the second preset current threshold. Based on this, when the battery pack's output current is large but does not exceed the first preset current threshold, the circuit breaker 2 will not burn out. The circuit breaker 2 will provide protection by shutting off the circuit, eliminating the need for fuse 1 to blow, thus saving the cost of fuse 1 and protecting the PCS. However, when the battery pack's output current exceeds the first preset current threshold, the circuit breaker 2 may burn out due to the large current. But since fuse 1 is connected between the battery pack and the circuit breaker 2, the large current output by the battery pack passes through fuse 1 first. When fuse 1 blows, the current cannot be transmitted to the circuit breaker 2, thus protecting the circuit breaker 2 and the downstream PCS.

[0047] Based on this, the battery pack's output current is protected at different current ranges. Specifically, when the battery pack's output current is between the second preset current threshold and the first preset current threshold, the circuit breaker 2 will shut it off for protection. When the battery pack's output current exceeds the first preset current threshold, the fuse 1 will blow it for protection. This not only saves the cost of the fuse 1 but also protects both the circuit breaker 2 and the PCS.

[0048] It should be noted that the second preset current threshold is the current exceeding the rated current of the battery pack, but not enough to burn out circuit breaker 2. The first preset current threshold, however, can be the short-circuit current, which can reach several thousand amperes. Therefore, fuse 1 is required for protection. Specifically, the model of fuse 1 can be selected to ensure it blows when the output current of the battery pack exceeds the first preset current threshold. Similarly, the model of circuit breaker 2 can be selected to ensure it turns off when the output current of the battery pack exceeds the second preset current threshold but is not greater than the first preset current threshold.

[0049] It should also be noted that the circuit breaker 2 in this application replaces the disconnecting switch in the prior art. Under normal conditions, the circuit breaker 2 remains closed, which can also isolate the circuit between the battery pack and the PCS.

[0050] In addition, other devices may be connected between the first terminal of the fuse 1 and the output terminal of the battery pack as needed, and this application does not limit this. Other devices may also be connected between the second terminal of the circuit breaker 2 and the first terminal of the PCS as needed, and this application does not limit this.

[0051] In summary, fuse 1 is positioned between the battery pack and circuit breaker 2, saving space on the PCS side of the energy storage high-voltage box. Furthermore, when the battery pack's output current increases significantly, such as exceeding the first preset current threshold, the current first passes through fuse 1, causing it to immediately melt and protect the subsequent circuit breaker 2 and the PCS. Conversely, when the battery pack's output current increases only slightly, i.e., between the second and first preset current thresholds, fuse 1 is not required for protection; instead, circuit breaker 2 provides shut-off protection. Circuit breaker 2 can close again once the battery pack's output current returns to normal, reducing the cost of fuse 1. Fuse 1 protects against large overcurrents, while circuit breaker 2 protects against small overcurrents, preventing component burnout and saving on component costs.

[0052] Based on the above embodiments:

[0053] Please refer to Figure 2 , Figure 2 A schematic diagram of the specific structure of a protection circuit provided by this utility model.

[0054] In a preferred embodiment, fuse 1 includes a first fuse 11 and a second fuse 12;

[0055] The first end of the first fuse 11 is connected to the positive output terminal of the battery pack, and the second end is connected to the first positive terminal of the circuit breaker 2.

[0056] The first end of the second fuse 12 is connected to the negative output terminal of the battery pack, and the second end is connected to the first negative terminal of the circuit breaker 2.

[0057] The second positive terminal of circuit breaker 2 is connected to the first positive terminal of PCS, and the second negative terminal of circuit breaker 2 is connected to the first negative terminal of PCS.

[0058] In this embodiment, the fuse 1 includes a first fuse 11 and a second fuse 12. The first fuse 11 is connected to the positive output terminal of the battery pack, and the second fuse 12 is connected to the negative output terminal of the battery pack. Based on this, the first fuse 11 and the second fuse 12 can respectively provide short-circuit protection for the positive and negative output terminals of the battery pack. When the output current of the battery pack is greater than a first preset current threshold, the first fuse 11 can provide fuse protection. However, when the negative output terminal of the battery pack experiences a short circuit to ground or other accidental grounding, the current at the negative output terminal may bypass the first fuse 11 and form a loop through other paths. In this case, the first fuse 11 cannot provide overcurrent protection or short-circuit protection, while the second fuse 12 can promptly melt and cut off the fault current.

[0059] Therefore, the first fuse 11 and the second fuse 12 can handle independent short circuits on either side of the positive or negative output terminal of the battery pack, covering more potential fault scenarios.

[0060] In a preferred embodiment, it also includes a current acquisition transformer 3, and the circuit breaker 2 includes a trip unit 21, a first contact 22 of the circuit breaker, and a second contact 23 of the circuit breaker;

[0061] The primary coil of the current acquisition transformer 3 is wound on the wire at the positive output terminal of the battery pack or on the wire at the negative output terminal of the battery pack, in order to sense the output current of the battery pack.

[0062] The secondary coil of the current acquisition transformer 3 is connected to the input terminal of the trip unit 21, and is used to transmit the current on the primary coil of the current acquisition transformer 3 to the trip unit 21;

[0063] The output terminal of the trip unit 21 is connected to the control terminal of the first contact 22 and the control terminal of the second contact 23 of the circuit breaker, and is used to control the first contact 22 and the second contact 23 of the circuit breaker to turn off when the output current of the battery pack is greater than the second preset current threshold and less than the first preset current threshold.

[0064] The first end of the first contact 22 of the circuit breaker is connected to the second end of the first fuse 11, and the second end is connected to the first positive end of the PCS.

[0065] The first end of the second contact 23 of the circuit breaker is connected to the second end of the second fuse 12, and the second end is connected to the first negative end of the PCS.

[0066] In this embodiment, the circuit breaker 2 uses a trip unit 21 to achieve automatic shutdown. The primary coil of the current acquisition transformer 3 is wound around the wire at the positive output terminal of the battery pack or around the wire at the negative output terminal of the battery pack to acquire the output current of the battery pack. The secondary coil of the current acquisition transformer 3 is connected to the trip unit 21 to transmit the acquired output current of the battery pack to the trip unit 21. When the output current of the battery pack is greater than the second preset current threshold and less than the first preset current threshold, the trip unit 21 controls the first contact 22 and the second contact 23 of the circuit breaker to close.

[0067] It should be noted that the turns ratio between the primary and secondary coils of the current acquisition transformer 3 can be greater than 1, so that the current on the secondary coil is less than the current on the primary coil, thereby avoiding the trip unit 21 from malfunctioning due to large current.

[0068] It should also be noted that different current acquisition transformers 3 can be set at the positive and negative output terminals of the battery pack respectively to provide overcurrent protection for the positive and negative output terminals of the battery pack respectively.

[0069] In addition, by setting the first contact 22 and the second contact 23 of the circuit breaker at the positive and negative output terminals of the battery pack respectively, overcurrent protection can be provided for both the positive and negative output terminals of the battery pack. Furthermore, the first contact 22 and the second contact 23 of the circuit breaker operate simultaneously to ensure that the circuit between the battery pack and the PCS is completely disconnected.

[0070] In a preferred embodiment, it also includes a contactor module and a control circuit 5;

[0071] The first positive terminal of the contactor module is connected to the second terminal of the first contact of the circuit breaker 2, the first negative terminal of the contactor module is connected to the second terminal of the second contact of the circuit breaker 2, the second positive terminal of the contactor module is connected to the first positive terminal of the PCS, and the second negative terminal of the contactor module is connected to the first negative terminal of the PCS.

[0072] The input terminal of the control circuit 5 is connected to the circuit breaker 2, and the output terminal of the control circuit 5 is connected to the control terminal of the contactor module. It is used to control the contactor module to turn off when a circuit off command is received, or when the circuit breaker 2 is turned off, or when the fuse 1 is blown.

[0073] In this embodiment, a contactor module is also provided between the circuit breaker 2 and the PCS. Since the circuit breaker 2 needs to be kept closed under normal conditions, when the battery pack needs maintenance or the fuse 1 needs to be replaced, the user can issue a circuit shutdown command to make the control circuit 5 control the contactor module to shut down, thereby disconnecting the circuit between the circuit breaker 2 and the PCS.

[0074] In addition, when circuit breaker 2 is detected to be off or fuse 1 is detected to be blown, control circuit 5 will also shut down the contactor module for further circuit protection.

[0075] It should be noted that the control circuit 5 is connected to the circuit breaker 2 to obtain the current flowing through the circuit breaker 2. If the circuit breaker 2 is turned off or the fuse 1 blows, then no current flows through the circuit breaker 2. At this time, the control circuit 5 will turn off the contactor module so that the staff can maintain the battery pack, replace the fuse 1, or manually control the circuit breaker 2 to turn on. Based on this, the controller will then turn the contactor module on again to protect the staff and ensure normal power transmission between the battery pack and the PCS.

[0076] It should also be noted that the control circuit 5 can reuse the battery management chip, and this application does not limit this.

[0077] In a preferred embodiment, the contactor module includes a first contactor 41 and a second contactor 42;

[0078] The first end of the first contactor 41 is connected to the second end of the first contact of the circuit breaker 2, the second end of the first contactor 41 is connected to the first positive end of the PCS, and the control end of the first contactor 41 is connected to the output end of the control circuit 5.

[0079] The first end of the second contactor 42 is connected to the second end of the second contact of the circuit breaker 2, the second end of the second contactor 42 is connected to the first negative end of the PCS, and the control end of the second contactor 42 is connected to the output end of the control circuit 5.

[0080] Considering that in a high-voltage battery system, even if the contactor at the positive output terminal of the battery pack is disconnected, if the contactor at the negative output terminal remains connected, the negative output terminal of the battery pack may form a loop with the load through grounding or other paths, leading to residual voltage or leakage current risks. Therefore, in this embodiment, a first contactor 41 and a second contactor 42 are respectively provided at the positive and negative output terminals of the battery pack. The bipolar contactors can completely disconnect the connection between the positive and negative terminals of the battery pack and the load, ensuring that the battery pack is completely disconnected from the system during maintenance or emergencies, avoiding the danger of electric shock or short circuit. The first contactor 41 and the second contactor 42 can be simultaneously turned on or off under the control of the control circuit 5, or they can be turned on or off separately under the control of the control circuit 5; this application does not limit this.

[0081] In a preferred embodiment, the battery pack is connected to the fuse 1, the fuse 1 to the circuit breaker 2, and the circuit breaker 2 to the PCS via a copper busbar 6.

[0082] In this embodiment, a copper busbar 6 is used to connect different devices. The copper busbar 6 has low resistivity, and for the same cross-sectional area as the aluminum busbar 6, it has higher conductivity, reducing energy loss and making it particularly suitable for connecting devices in high-current scenarios. Furthermore, under the same temperature rise conditions, the current carrying capacity of the copper busbar 6 is approximately 30% higher than that of the aluminum busbar, allowing for a smaller conductor cross-sectional area and saving installation space. The copper busbar 6 has high tensile strength, making it less prone to deformation or breakage under vibration, impact, or thermal expansion and contraction. Moreover, because copper is easily processed into complex shapes, its connection reliability is high, reducing the risk of poor contact. When the copper busbar 6 is connected to copper terminals, the degree of oxidation at the contact surface is small, and the contact resistance is stable, reducing the risk of overheating and arcing.

[0083] In a preferred embodiment, it also includes a current acquisition module and an alarm module;

[0084] The input terminal of the current acquisition module is connected to the output terminal of the battery pack to acquire the output current of the battery pack;

[0085] The input terminal of the alarm module is connected to the output terminal of the current acquisition module, and is used to output a first alarm signal when the output current of the battery pack is greater than a first preset current threshold, and to output a second alarm signal when the output current of the battery pack is greater than a second preset current threshold and less than the first preset current threshold.

[0086] In this embodiment, protection is provided not only by circuit breaker 2 or fuse 1 when the output current of the battery pack is too high, but also by an alarm module. Specifically, the current acquisition module acquires the output current of the battery pack in real time. When the output current of the battery pack is greater than the first preset current threshold, a first alarm signal is output. When the output current of the battery pack is greater than the second preset current threshold but less than the first preset current threshold, a second alarm signal is output. The first alarm signal and the second alarm signal are not the same, and the urgency of the first alarm signal is greater than that of the second alarm signal.

[0087] It should be noted that the current acquisition module in this embodiment can reuse the current acquisition transformer 3 mentioned above, or the control circuit 5 can control the alarm circuit to output a first alarm signal to trigger an alarm when it determines that the output current of the battery pack is greater than the first preset current threshold, and control the alarm circuit to output a second alarm signal to trigger an alarm when the output current of the battery pack is greater than the second preset current threshold and less than the first preset current threshold. This application does not limit this.

[0088] In one preferred embodiment, the alarm module includes an audible alarm circuit;

[0089] The sound alarm circuit is used to emit a sound wave of a first frequency when the output current of the battery pack is greater than a first preset current threshold, and to emit a sound wave of a second frequency when the output current of the battery pack is greater than a second preset current threshold but less than the first preset current threshold; the first frequency is greater than the second frequency.

[0090] The alarm circuit in this embodiment may include, but is not limited to, a sound alarm circuit. The sound alarm circuit provides an audible alarm so that staff can be notified of excessive output current of the battery pack when it is inconvenient to check the working status of the battery pack, and can perform maintenance in a timely manner.

[0091] Specifically, the audible alarm circuit can trigger different frequencies of sound waves based on the output current of the battery pack. For example, when the output current exceeds a first preset current threshold, it indicates that the output current is too high and its adverse effects are significant. Therefore, the audible alarm circuit will trigger a higher-frequency sound wave. Conversely, when the output current exceeds a second preset current threshold but is less than the first, it indicates that while the output current is high, its impact is not significant. Therefore, the audible alarm circuit will trigger a lower-frequency sound wave. Operators can determine the degree of abnormal increase in the battery pack's output current and the urgency of maintenance required for the battery pack or the entire circuit based on the frequency of the sound waves.

[0092] Of course, the sound alarm circuit can be divided into a first sound alarm module and a second sound alarm module. The first sound alarm module is used to emit a sound wave of a first frequency when the output current of the battery pack is greater than a first preset current threshold, and the second sound alarm module is used to emit a sound wave of a second frequency when the output current of the battery pack is greater than a second preset current threshold and less than a first preset current threshold. Based on this, the functions of the first sound alarm module and the second sound alarm module are distinguished to avoid false alarms.

[0093] In addition, the sound alarm circuit can be a horn or a buzzer, and this application does not limit it to this.

[0094] In one preferred embodiment, the alarm module includes a light alarm circuit;

[0095] The light alarm circuit is used to illuminate the light in a first light mode when the output current of the battery pack is greater than a first preset current threshold, and to illuminate the light in a second light mode when the output current of the battery pack is greater than a second preset current threshold but less than the first preset current threshold; the brightness of the first light mode is greater than the brightness of the second light mode, and / or the color temperature of the first light mode is lower than the color temperature of the second light mode.

[0096] The alarm module in this embodiment may include, but is not limited to, a light alarm circuit. The light alarm circuit uses light to alert staff in noisy environments that the battery pack's output current is too high, allowing for timely maintenance.

[0097] Specifically, the lighting alarm circuit can activate different lighting modes based on the output current of the battery pack. For example, when the battery pack's output current exceeds a first preset current threshold, it indicates that the output current is too high and its adverse effects are significant. Therefore, the lighting alarm circuit will activate the first lighting mode to sound the alarm. Conversely, when the battery pack's output current exceeds a second preset current threshold but is less than the first preset current threshold, it indicates that although the output current is high, its impact is not significant. Therefore, the lighting alarm circuit will activate the second lighting mode to sound the alarm. Operators can determine the degree of abnormal increase in the battery pack's output current and the urgency of maintaining the battery pack or the entire circuit based on the lighting mode of the lighting alarm circuit.

[0098] Specifically, the brightness of the first lighting mode is greater than that of the second lighting mode, and / or the color temperature of the first lighting mode is lower than that of the second lighting mode. Based on this, staff can determine that the urgency level is higher in the first lighting mode. For example, the light color corresponding to the first lighting mode is red, while the light color corresponding to the second lighting mode is blue.

[0099] Of course, the light alarm circuit can be divided into a first light alarm module and a second light alarm module. The first light alarm module is used to light up the light in the first light mode when the output current of the battery pack is greater than the first preset current threshold. The second light alarm module is used to light up the light in the second light mode when the output current of the battery pack is greater than the second preset current threshold and less than the first preset current threshold. Based on this, the functions of the first light alarm module and the second light alarm module are distinguished to avoid false alarms.

[0100] In addition, the light alarm circuit can be an LED light or a display screen, and this application does not limit it.

[0101] Figure 3 A schematic diagram of an energy storage high-voltage box provided by this utility model, including the protection circuit as described above;

[0102] The fuse 1 in the protection circuit is located on the side of the energy storage high-voltage box near the battery pack, and the contactor module in the protection circuit is located on the side of the energy storage high-voltage box near the PCS.

[0103] The first fuse 11 in the energy storage high-voltage box is connected to the first end of the first contact of the circuit breaker 2 via the copper busbar 6, and the second fuse 12 is connected to the first end of the second contact of the circuit breaker 2 via the copper busbar 6. It can be seen that the first fuse 11 and the second fuse 12 are located on the side of the energy storage high-voltage box near the battery pack. The second end of the first fuse 11 is connected to the first end of the first contact of the relay, and the second end of the second fuse 12 is connected to the first end of the second contact of the relay. The first contactor 41 and the second contactor 42 are located on the side of the energy storage high-voltage box near the PCS. The first end of the first contactor 41 is connected to the second end of the first contact of the relay, and the first end of the second contactor 42 is connected to the second end of the second contact of the relay. This saves space between the circuit breaker 2 and the PCS, and saves copper busbar and space pressure behind the circuit breaker 2, that is, on the side of the energy storage high-voltage box near the PCS.

[0104] For an introduction to the energy storage high-voltage box provided by this utility model, please refer to the above-described embodiment of the protection circuit; this utility model will not be described in detail here.

[0105] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0106] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A protection circuit, characterized in that, Including circuit breakers and fuses; The first end of the fuse is connected to the output end of the battery pack, and the second end is connected to the first end of the circuit breaker, for use to melt when the output current of the battery pack is greater than a first preset current threshold. The second terminal of the circuit breaker is connected to the first terminal of the PCS and is used to turn off the circuit when the output current of the battery pack is greater than the second preset current threshold and not greater than the first preset current threshold; the first preset current threshold is greater than the second preset current threshold.

2. The protection circuit as described in claim 1, characterized in that, The fuse includes a first fuse and a second fuse; The first end of the first fuse is connected to the positive output terminal of the battery pack, and the second end is connected to the first positive terminal of the circuit breaker. The first end of the second fuse is connected to the negative output terminal of the battery pack, and the second end is connected to the first negative terminal of the circuit breaker. The second positive terminal of the circuit breaker is connected to the first positive terminal of the PCS, and the second negative terminal of the circuit breaker is connected to the first negative terminal of the PCS.

3. The protection circuit as described in claim 2, characterized in that, It also includes a current acquisition transformer, and the circuit breaker includes a trip unit, a first contact of the circuit breaker, and a second contact of the circuit breaker; The primary coil of the current acquisition transformer is wound around the wire at the positive output terminal of the battery pack or around the wire at the negative output terminal of the battery pack, in order to sense the output current of the battery pack. The secondary coil of the current acquisition transformer is connected to the input terminal of the trip unit, and is used to transmit the current on the primary coil of the current acquisition transformer to the trip unit; The output terminal of the trip unit is connected to the control terminal of the first contact and the control terminal of the second contact of the circuit breaker, and is used to control the first contact and the second contact of the circuit breaker to turn off when the output current of the battery pack is greater than the second preset current threshold and not greater than the first preset current threshold. The first end of the first contact of the circuit breaker is connected to the second end of the first fuse, and the second end is connected to the first positive end of the PCS. The first end of the second contact of the circuit breaker is connected to the second end of the second fuse, and the second end is connected to the first negative end of the PCS.

4. The protection circuit as described in claim 3, characterized in that, It also includes contactor modules and control circuits; The first positive terminal of the contactor module is connected to the second terminal of the first contact of the circuit breaker, the first negative terminal of the contactor module is connected to the second terminal of the second contact of the circuit breaker, the second positive terminal of the contactor module is connected to the first positive terminal of the PCS, and the second negative terminal of the contactor module is connected to the first negative terminal of the PCS. The input terminal of the control circuit is connected to the circuit breaker, and the output terminal of the control circuit is connected to the control terminal of the contactor module, for controlling the contactor module to turn off when a circuit off command is received, or when the circuit breaker is detected to be off, or when the fuse is detected to be blown.

5. The protection circuit as described in claim 4, characterized in that, The contactor module includes a first contactor and a second contactor; The first end of the first contactor is connected to the second end of the first contact of the circuit breaker, the second end of the first contactor is connected to the first positive end of the PCS, and the control end of the first contactor is connected to the output end of the control circuit. The first end of the second contactor is connected to the second end of the second contact of the circuit breaker, the second end of the second contactor is connected to the first negative terminal of the PCS, and the control end of the second contactor is connected to the output end of the control circuit.

6. The protection circuit as described in claim 1, characterized in that, The battery pack is connected to the fuse, the fuse to the circuit breaker, and the circuit breaker to the PCS via copper busbars.

7. The protection circuit as described in any one of claims 1-6, characterized in that, It also includes a current acquisition module and an alarm module; The input terminal of the current acquisition module is connected to the output terminal of the battery pack, and is used to acquire the output current of the battery pack; The input terminal of the alarm module is connected to the output terminal of the current acquisition module, and is used to output a first alarm signal when the output current of the battery pack is greater than the first preset current threshold, and to output a second alarm signal when the output current of the battery pack is greater than the second preset current threshold but not greater than the first preset current threshold.

8. The protection circuit as described in claim 7, characterized in that, The alarm module includes an audible alarm circuit; The sound alarm circuit is used to emit a sound wave of a first frequency when the output current of the battery pack is greater than the first preset current threshold, and to emit a sound wave of a second frequency when the output current of the battery pack is greater than the second preset current threshold but not greater than the first preset current threshold; the first frequency is greater than the second frequency.

9. The protection circuit as described in claim 7, characterized in that, The alarm module includes a light alarm circuit; The light alarm circuit is used to illuminate the light in a first light mode when the output current of the battery pack is greater than the first preset current threshold, and to illuminate the light in a second light mode when the output current of the battery pack is greater than the second preset current threshold but not greater than the first preset current threshold; the brightness of the first light mode is greater than the brightness of the second light mode, and / or the color temperature of the first light mode is lower than the color temperature of the second light mode.

10. A high-voltage energy storage box, characterized in that, Includes the protection circuit as described in any one of claims 1-9; The fuse in the protection circuit is located on the side of the energy storage high-voltage box closer to the battery pack, and the contactor module in the protection circuit is located on the side of the energy storage high-voltage box closer to the PCS.

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