Pressure relief circuit and power supply system

Abstract

The utility model relates to the technical field of batteries, and discloses a voltage release circuit and a power supply system. The voltage release circuit comprises a first switching device, a voltage release pre-charging switch and a voltage release pre-charging load, the first switching device comprises a first battery connecting end and a first electric equipment connecting end, the first battery connecting end is electrically connected to the positive electrode of the battery assembly, the first electric equipment connecting end is electrically connected to one end of capacitive electric equipment, and the first battery connecting end is electrically connected to the negative electrode of the battery assembly. The other end of the capacitive electric equipment is electrically connected to the negative electrode of the battery assembly; the pressure relief pre-charging switch is provided with at least two selection contacts, the at least two selection contacts comprise a first selection contact and a second selection contact, the first selection contact is connected with the pressure relief pre-charging load in series and then connected with the first switching device in parallel, and the second selection contact is electrically connected to the negative electrode of the battery assembly. The voltage release circuit can consume charges stored in the capacitive electric equipment, misjudgment is avoided, pre-charging can be achieved, the usage amount of components is saved, and therefore the cost is reduced.

Description

Technical Field

[0001] This disclosure relates to the field of battery technology, and more specifically, to a pressure relief circuit and a power supply system including the pressure relief circuit. Background Technology

[0002] In the prior art, the power system is effectively managed by the Battery Management System (BMS). Specifically, the battery management system monitors the operating status of the power system by detecting the voltage at various detection points.

[0003] However, if the power system uses capacitive devices, after the power system is powered off, a false voltage will be generated at one end of the capacitive device due to the capacitor. This voltage will be detected by the battery management system through the detection point, causing the battery management system to misjudge the working status of the power system, resulting in the inability to perform the next action or performing the next action incorrectly.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a pressure relief circuit and a power supply system including the pressure relief circuit.

[0006] According to one aspect of this disclosure, a pressure relief circuit is provided, electrically connected between a battery pack and a capacitive electrical device, the pressure relief circuit comprising:

[0007] A first switching device includes a first battery connection terminal and a first electrical device connection terminal. The first battery connection terminal is electrically connected to the positive terminal of the battery assembly, and the first electrical device connection terminal is electrically connected to one end of the capacitive electrical device. The other end of the capacitive electrical device is electrically connected to the negative terminal of the battery assembly.

[0008] The device includes a pressure relief precharge switch and a pressure relief precharge load. The pressure relief precharge switch has at least two selection contacts, including a first selection contact and a second selection contact. The first selection contact is connected in series with the pressure relief precharge load and then connected in parallel with the first switching device. The second selection contact is electrically connected to the negative terminal of the battery assembly.

[0009] In one exemplary embodiment of this disclosure, the pressure relief precharge switch has two selection contacts, the first selection contact being a normally closed contact, and the pressure relief circuit further includes:

[0010] The precharge switch is connected in series with the first selection contact and the pressure relief precharge load.

[0011] In one exemplary embodiment of this disclosure, the pressure relief precharge switch further includes a third selection contact, which is a normally closed selection contact and is an unused contact.

[0012] In one exemplary embodiment of this disclosure, the pressure relief circuit further includes:

[0013] The second switching device includes a second battery connection terminal and a second electrical device connection terminal. The second battery connection terminal is electrically connected to the negative terminal of the battery assembly, the second electrical device connection terminal is electrically connected to the capacitive electrical device, and the second selection contact is electrically connected to the second electrical device connection terminal.

[0014] In one exemplary embodiment of this disclosure, the first switching device and the pressure relief precharge switch are relays.

[0015] In one exemplary embodiment of this disclosure, the pressure relief circuit further includes:

[0016] The battery management system is electrically connected to the control terminal of the first switching device and the control terminal of the pressure relief precharge switch, and is also electrically connected to the connection terminal of the first electrical device and the negative terminal of the battery assembly.

[0017] In one exemplary embodiment of this disclosure, when the pressure relief circuit includes a precharge switch and / or a second switching device, the precharge switch and / or the second switching device is a relay.

[0018] In one exemplary embodiment of this disclosure, the battery management system is also electrically connected to the control terminal of the precharge switch and / or the control terminal of the second switching device, and electrically connected to the second electrical device connection terminal of the second switching device.

[0019] In one exemplary embodiment of this disclosure, the pressure relief circuit further includes:

[0020] A fuse is electrically connected between the battery assembly and the first switching device.

[0021] According to another aspect of this disclosure, a power supply system is provided, comprising:

[0022] Battery components;

[0023] Capacitive electrical equipment;

[0024] The pressure relief circuit is any one of the pressure relief circuits described above, and the pressure relief circuit is electrically connected between the battery assembly and the capacitive electrical device.

[0025] The pressure relief circuit disclosed herein, on the one hand, disconnects the first switching device, disconnecting the capacitive electrical device from the battery pack to complete power-off. Then, the pressure relief pre-charge switch closes at the second selector contact, connecting the capacitive electrical device to the pressure relief pre-charge load. The pressure relief pre-charge load can consume the charge stored in the capacitive electrical device. After the pressure relief pre-charge load has consumed all the charge stored in the capacitive electrical device, the second selector contact of the pressure relief pre-charge switch is opened (closing it to the normally closed contact) to complete pressure relief. This avoids the Battery Management System (BMS) detecting false pressure generated by the capacitive electrical device, which could lead to misjudgment of the power system's operating state by the BMS, thus ensuring that the BMS control proceeds to the next step. The operation is accurate and error-free. On the other hand, closing the pressure relief precharge switch at the first selector contact connects the battery pack to the capacitive electrical equipment and the pressure relief precharge load, precharging the first electrical equipment connection terminal. When the battery management system (BMS) detects that the voltage between the first electrical equipment connection terminal and the negative terminal of the battery pack is close to the battery pack voltage, it closes the first switch device and then disconnects the pressure relief precharge load from the battery pack, completing the power-on process. This avoids excessive current in the first switch device at the moment of power-on, which could damage the first switch device. Furthermore, by using the pressure relief precharge switch and the pressure relief precharge load to achieve the functions of pressure relief and precharge, the number of components used is reduced, thereby lowering costs and improving production efficiency.

[0026] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0028] Figure 1 This is a schematic diagram of an example embodiment of the power supply system disclosed herein.

[0029] Figure 2 This is a schematic diagram of another example embodiment of the power supply system disclosed herein.

[0030] Figure 3 for Figure 1 and Figure 2 A schematic diagram of the connection structure between the switching devices and the battery management system.

[0031] Explanation of reference numerals in the attached figures:

[0032] 10. Pressure relief circuit;

[0033] KM1, first switching device; KM11, first battery connection terminal; KM12, first electrical equipment connection terminal;

[0034] KM2, second switching device; KM21, second battery connection terminal; KM22, second electrical equipment connection terminal;

[0035] KM3, pressure relief and pre-charge switch; KM31, first selection contact; KM32, second selection contact; KM33, third selection contact;

[0036] R1, pressure relief and pre-charge load;

[0037] KM4, pre-charge switch;

[0038] BMS, Battery Management System; DI1, First Input Interface; DI2, Second Input Interface; DI3, Third Input Interface; DI4, Fourth Input Interface; DO1, First Output Interface; DO2, Second Output Interface; DO3, Third Output Interface; DO4, Fourth Output Interface; DO5, Fifth Output Interface; DO6, Sixth Output Interface; DO7, Seventh Output Interface; DO8, Eighth Output Interface; DY+, Positive Power Interface; DY-, Negative Power Interface;

[0039] FU1, fuse; DC, battery pack; SB, capacitive electrical equipment;

[0040] KM5, charging switch; CD, charging interface. Detailed Implementation

[0041] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0042] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0043] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0044] In this application, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. "And / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Furthermore, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0045] This disclosure provides an exemplary embodiment of a pressure relief circuit 10, with reference to... Figures 1-3 As shown, the pressure relief circuit 10 is electrically connected between the battery module DC and the capacitive electrical device SB. The pressure relief circuit 10 may include a first switching device KM1, a pressure relief precharge switch KM3, and a pressure relief precharge load R1. The first switching device KM1 may include a first battery connection terminal KM11 and a first electrical device connection terminal KM12. The first battery connection terminal KM11 is electrically connected to the positive terminal of the battery module DC, and the first electrical device connection terminal KM12 is electrically connected to one end of the capacitive electrical device SB. The other end of the capacitive electrical device SB is electrically connected to the negative terminal of the battery module DC. The pressure relief precharge switch KM3 has at least two selection contacts, which may include a first selection contact KM31 and a second selection contact KM32. The first selection contact KM31 is connected in series with the pressure relief precharge load R1 and then connected in parallel with the first switching device KM1. The second selection contact KM32 is electrically connected to the negative terminal of the battery module DC.

[0046] The pressure relief circuit 10 disclosed herein, on the one hand, disconnects the first switching device KM1, disconnecting the capacitive power device SB from the DC power of the battery pack to complete power-off. Then, the pressure relief pre-charge switch KM3 closes the second selection contact KM32, connecting the capacitive power device SB to the pressure relief pre-charge load R1. The pressure relief pre-charge load R1 can consume the charge stored in the capacitive power device SB. After the pressure relief pre-charge load R1 consumes all the charge stored in the capacitive power device SB, it disconnects the second selection contact KM32 of the pressure relief pre-charge switch KM3 (closing it to the normally closed contact) to complete pressure relief. This avoids the battery management system (BMS) detecting false pressure generated by the capacitive power device SB, which could lead to misjudgment of the power system's operating state by the BMS, thus ensuring the accuracy of the BMS control in performing the next action. This is indeed correct. On the other hand, closing the pressure relief precharge switch KM3 at the first selection contact KM31 connects the battery module DC to the capacitive power device SB and the pressure relief precharge load R1, precharging the connection terminal KM12 of the first power device. When the battery management system (BMS) detects that the voltage between the connection terminal KM12 of the first power device and the negative terminal of the battery module DC is close to the voltage of the battery module DC, it closes the first switching device KM1 and then disconnects the connection between the pressure relief precharge load R1 and the battery module DC, completing the power-on process. This avoids excessive current in the first switching device KM1 at the moment of power-on, which could damage the first switching device KM1. Furthermore, by using the pressure relief precharge switch KM3 and the pressure relief precharge load R1 to achieve the functions of pressure relief and precharge, the number of components used is reduced, thereby lowering costs and improving production efficiency.

[0047] In this example implementation, refer to Figure 1 and Figure 2 As shown, the first switching device KM1 has a first battery connection terminal KM11 and a first electrical device connection terminal KM12. The first battery connection terminal KM11 is electrically connected to the positive terminal of the DC battery of the battery pack. The first switching device KM1 realizes the conduction and disconnection of the first battery connection terminal KM11 and the first electrical device connection terminal KM12. For example, when the first switching device KM1 is closed, the first battery connection terminal KM11 and the first electrical device connection terminal KM12 are connected; when the first switching device KM1 is open, the first battery connection terminal KM11 and the first electrical device connection terminal KM12 are disconnected.

[0048] One end of the capacitive electrical device SB is electrically connected to the first electrical device connection terminal KM12, and the other end of the capacitive electrical device SB is electrically connected to the negative terminal of the battery pack DC. The connection and disconnection between the capacitive electrical device SB and the battery pack DC can be realized through the first switching device KM1. For example, when the first switching device KM1 is closed, the capacitive electrical device SB is connected to the battery pack DC, and the battery pack DC can provide power to the capacitive electrical device SB, so that the capacitive electrical device SB can work; when the first switching device KM1 is open, the capacitive electrical device SB is disconnected from the battery pack DC, and the battery pack DC cannot provide power to the capacitive electrical device SB, so that the capacitive electrical device SB stops working.

[0049] Capacitive electrical equipment SB may include one, two or more electrical equipment. Two electrical equipment may be connected in series or in parallel; multiple electrical equipment may be connected in series or in parallel, or may be a combination of series and parallel connection structures.

[0050] A capacitive electrical device SB generally refers to a load with capacitance parameters, that is, a load that exhibits the characteristic of current leading voltage. During charging and discharging, the voltage of a capacitive electrical device SB cannot change abruptly, and its corresponding power factor is negative, while the power factor of an inductive load is positive. In this example embodiment, the capacitive electrical device SB may include one, two, or three of the following: a motor, an air compressor, a DC-to-DC converter, etc. Of course, the capacitive electrical device SB may also include other electrical devices, which will not be described in detail here.

[0051] In this example implementation, refer to Figure 1 and Figure 2 As shown, the pressure relief precharge switch KM3 has at least two selection contacts. For example, the pressure relief precharge switch KM3 may have two selection contacts or three selection contacts. The at least two selection contacts of the pressure relief precharge switch KM3 may include a first selection contact KM31 and a second selection contact KM32.

[0052] The first selection contact KM31 of the pressure relief precharge switch KM3 is connected in series with the pressure relief precharge load R1 and then connected in parallel with the first switching device KM1.

[0053] The pre-charge load R1 is electrically connected to the common contact of the pre-charge switch KM3 and is also electrically connected between the pre-charge switch KM3 and the capacitive electrical device SB. Specifically, the first selection contact KM31 of the pre-charge switch KM3 is electrically connected to the first battery connection terminal KM11, the common contact of the pre-charge switch KM3 is electrically connected to one end of the pre-charge load R1, and the other end of the pre-charge load R1 is electrically connected to the first electrical device connection terminal KM12. This allows the first selection contact KM31 and the pre-charge load R1 to be connected in series and then connected in parallel with the first switching device KM1.

[0054] Furthermore, the second selection contact KM32 of the pressure relief precharge switch KM3 is electrically connected to the negative terminal of the DC of the battery pack.

[0055] The pre-charge switch KM3 and the pre-charge load R1 can dissipate the charge stored in the capacitive device SB. Specifically, the first switching device KM1 is opened, the capacitive device SB is disconnected from the DC power of the battery pack, and power is turned off. Then, the pre-charge switch KM3 is closed at the second selection contact KM32, so that the capacitive device SB is connected to the pre-charge load R1. The pre-charge load R1 can dissipate the charge stored in the capacitive device SB. After a few seconds, for example, after about 3 seconds, the pre-charge load R1 can consume all the charge stored in the capacitive device SB. Finally, the second selection contact KM32 of the pre-charge switch KM3 is opened (closing it to the normally closed contact) to complete the pressure relief. This avoids the battery management system (BMS) from detecting the false voltage generated by the capacitive device SB, which could lead to misjudgment of the power system's operating status by the BMS, thus ensuring the accuracy of the BMS control in performing the next action.

[0056] Furthermore, the pressure relief pre-charge switch KM3 and the pressure relief pre-charge load R1 can pre-charge the connection terminal KM12 of the first electrical equipment, thus preventing the first switching device KM1 from being damaged due to excessive current at the moment of power-on.

[0057] Specifically, the pressure relief precharge switch KM3 is closed at the first selection contact KM31, connecting the battery module DC to the capacitive device SB and the pressure relief precharge load R1, thus precharging the connection terminal KM12 of the first device. When the battery management system (BMS) detects that the voltage between the connection terminal KM12 of the first device and the negative terminal of the battery module DC is close to the battery module DC voltage, specifically, when the BMS detects that the voltage between the connection terminal KM12 of the first device and the negative terminal of the battery module DC is greater than or equal to 90% of the battery module DC voltage, for example, when the BMS detects that the voltage between the connection terminal KM12 of the first device and the negative terminal of the battery module DC is 93%, 95%, or 97.5% of the battery module DC voltage, the first switching device KM1 is closed, and the connection between the pressure relief precharge load R1 and the battery module DC is disconnected, completing the power-on process.

[0058] Optionally, both the first switching device KM1 and the pressure relief precharge switch KM3 are relays. A relay is an electronic control device with a control system (also known as an input circuit) and a controlled system (also known as an output circuit). The working principle of a relay is mainly to control the on / off state of a circuit using electromagnetic induction or certain physical effects. When the coil of the relay is energized, a magnetic field is generated around it. This magnetic field attracts the contacts, causing them to close or open, thereby controlling the on / off state of the circuit. For electromagnetic relays, the basic principle is to use electromagnetic effects to control mechanical contacts to achieve the purpose of on / off switching. Specifically, when the coil is energized, the coil current generates a magnetic field, which attracts the armature to actuate and open / close the contacts. Solid-state relays, on the other hand, achieve electrical isolation and control of input and output through electronic components. This results in both the first switching device KM1 and the pressure relief precharge switch KM3 having two coil terminals, which are their respective control terminals.

[0059] The first switching device KM1 and the pressure relief precharge switch KM3 can also be contactors. Of course, in some other example embodiments of this disclosure, the first switching device KM1 and the pressure relief precharge switch KM3 can also be other switching devices with similar functions, which will not be described one by one here.

[0060] Reference Figure 3 As shown, Figure 3 The diagram only shows the connection relationships between the Battery Management System (BMS) and the coil terminals of the first switching device KM1, the second switching device KM2, and the pressure relief precharge switch KM3 and the precharge switch KM4. The connection relationships between the first switching device KM1, the second switching device KM2, and the pressure relief precharge switch KM3 and the precharge switch KM4 and other devices are not shown. The connection relationships between the first switching device KM1, the second switching device KM2, and the pressure relief precharge switch KM3 and the precharge switch KM4 and other devices are as follows: Figure 1and Figure 2 As shown, the pressure relief circuit 10 may further include a battery management system (BMS). The BMS is electrically connected to the control terminal of the first switching device KM1 and the control terminal of the pressure relief pre-charge switch KM3. Specifically, the BMS has a first output interface DO1, a second output interface DO2, a fifth output interface DO5, and a sixth output interface DO6. The first output interface DO1 and the second output interface DO2 can be electrically connected to the two coil terminals of the first switching device KM1 in a one-to-one correspondence, and the fifth output interface DO5 and the sixth output interface DO6 can be electrically connected to the two coil terminals of the pressure relief pre-charge switch KM3 in a one-to-one correspondence. The BMS can control the closing or opening of the first switching device KM1 and the pressure relief pre-charge switch KM3.

[0061] The Battery Management System (BMS) is also electrically connected to the first electrical device connection terminal KM12 and the negative terminal DC- of the battery pack. Specifically, the BMS has a first input interface DI1 and a second input interface DI2. The first input interface DI1 can be electrically connected to the first electrical device connection terminal KM12, and the second input interface DI2 can be electrically connected to the negative terminal DC of the battery pack. The BMS can collect the voltage between the first electrical device connection terminal KM12 and the negative terminal DC of the battery pack, and then use the collected voltage to control the closing or opening of the first switching device KM1 and the pre-charge discharge switch KM3.

[0062] The battery management system (BMS) may also include a positive power interface DY+ and a negative power interface DY-, which are electrically connected to a DC power supply, allowing the BMS to be powered by the DC power supply.

[0063] Of course, in some other exemplary embodiments of this disclosure, the first switching device KM1 and the pressure relief precharge switch KM3 can be manual switches. In this case, the battery management system (BMS) may not be provided, or the battery management system (BMS) may be provided, but the first switching device KM1 and the pressure relief precharge switch KM3 may not be electrically connected to the battery management system (BMS).

[0064] Reference Figure 1As shown, in some exemplary embodiments of this disclosure, the pressure relief precharge switch KM3 has two selector contacts. In this case, the first selector contact KM31 is a normally closed contact, meaning that the pressure relief precharge switch KM3 is generally closed at the first selector contact KM31 when no action is taken. The second selector contact KM32 is a normally open contact. The pressure relief circuit 10 may also include a precharge switch KM4, which is connected in series with the first selector contact KM31 and the pressure relief precharge load R1. Specifically, one end of the precharge switch KM4 is electrically connected to the first battery connection terminal KM11, and the other end of the precharge switch KM4 is electrically connected to the first selection contact KM31 of the pressure relief precharge switch KM3. The common contact of the pressure relief precharge switch KM3 is electrically connected to one end of the pressure relief precharge load R1, and the other end of the pressure relief precharge load R1 is electrically connected to the first electrical equipment connection terminal KM12. Thus, the precharge switch KM4, the first selection contact KM31, and the pressure relief precharge load R1 are connected in series and then connected in parallel with the first switching device KM1.

[0065] The power-on process in this example embodiment is as follows: The pre-charge switch KM4 is closed, and the pressure relief pre-charge switch KM3 is closed at the first selection contact KM31 (generally in the closed state), connecting the battery module DC to the capacitive device SB and the pressure relief pre-charge load R1, thus pre-charging the first device connection terminal KM12. When the battery management system (BMS) detects that the voltage between the first device connection terminal KM12 and the negative terminal of the battery module DC is close to the battery module DC voltage, specifically, when the BMS detects that the voltage between the first device connection terminal KM12 and the negative terminal of the battery module DC is greater than or equal to 90% of the battery module DC voltage, for example, when the BMS detects that the voltage between the first device connection terminal KM12 and the negative terminal of the battery module DC is 93%, 95%, or 97.5% of the battery module DC voltage, the first switching device KM1 is closed, and the pre-charge switch KM4 is then opened, completing the power-on process.

[0066] The power-down process is as follows: the first switching device KM1 is disconnected, the capacitive device SB is disconnected from the battery pack DC to complete the power-down. Then, the pressure relief pre-charge switch KM3 is closed at the second selection contact KM32, so that the capacitive device SB is connected to the pressure relief pre-charge load R1. The pressure relief pre-charge load R1 can consume the charge stored in the capacitive device SB. When the battery management system BMS detects that the voltage between the first device connection terminal KM12 and the negative terminal of the battery pack DC is basically 0, the second selection contact KM32 of the pressure relief pre-charge switch KM3 is disconnected, that is, the pressure relief pre-charge switch KM3 is closed to the first selection contact KM31 (normally closed contact) to complete the pressure relief.

[0067] Reference Figure 2As shown, in some exemplary embodiments of this disclosure, the pressure relief precharge switch KM3 has three selection contacts, namely, the pressure relief precharge switch KM3 also includes a third selection contact KM33, the third selection contact KM33 is a normally closed selection contact, and the third selection contact KM33 is an unused contact, so that when the pressure relief precharge switch KM3 is closed at the third selection contact KM33 (normally closed selection contact), it cannot form a current loop with other components.

[0068] The power-on process in this example embodiment is as follows: the pre-charge switch KM3 is closed at the first selector contact KM31, connecting the battery module DC to the capacitive device SB and the pre-charge load R1, pre-charging the first device connection terminal KM12. When the battery management system (BMS) detects that the voltage between the first device connection terminal KM12 and the negative terminal of the battery module DC is close to the battery module DC voltage, specifically, when the BMS detects that the voltage between the first device connection terminal KM12 and the negative terminal of the battery module DC is greater than or equal to 90% of the battery module DC voltage, for example, when the BMS detects that the voltage between the first device connection terminal KM12 and the negative terminal of the battery module DC is 93%, 95%, or 97.5% of the battery module DC voltage, the first switch KM1 is closed, and then the pre-charge switch KM3 is closed at the third selector contact KM33 (normally closed selector contact), completing the power-on process.

[0069] The power-down process is basically the same as that in the previous example implementation, and will not be described again here. The difference is that after the second selection contact KM32 of the pressure relief precharge switch KM3 is disconnected, in this example implementation, the pressure relief precharge switch KM3 closes to the third selection contact KM33.

[0070] This example implementation is relative to Figure 1 The example implementation shown reduces the use of the precharge switch KM4, therefore, relative to Figure 1 The example implementation shown can reduce costs.

[0071] In other example embodiments of this disclosure, reference is made to Figure 1 and Figure 2As shown, the pressure relief circuit 10 may further include a second switching device KM2. The second switching device KM2 has a second battery connection terminal KM21 and a second electrical device connection terminal KM22. The second battery connection terminal KM21 is electrically connected to the negative terminal of the DC battery pack, and the second electrical device connection terminal KM22 is electrically connected to the capacitive electrical device SB. The second switching device KM2 enables the second battery connection terminal KM21 and the second electrical device connection terminal KM22 to be turned on and off. For example, when the second switching device KM2 is closed, the second battery connection terminal KM21 and the second electrical device connection terminal KM22 are connected; when the second switching device KM2 is open, the second battery connection terminal KM21 and the second electrical device connection terminal KM22 are disconnected.

[0072] The connection and disconnection between the capacitive electrical device SB and the battery module DC are achieved through the joint action of the first switching device KM1 and the second switching device KM2. For example, when both the first switching device KM1 and the second switching device KM2 are closed, the capacitive electrical device SB is connected to the battery module DC, allowing the battery module DC to provide power to the capacitive electrical device SB, enabling it to operate. If either the first switching device KM1 or the second switching device KM2 is open, the capacitive electrical device SB is disconnected from the battery module DC, preventing the battery module DC from providing power to the capacitive electrical device SB and causing it to stop operating. This ensures the determinism of the connection and disconnection between the capacitive electrical device SB and the battery module DC, further guaranteeing the safety of the power supply system.

[0073] In this case, the second selection contact KM32 of the pressure relief precharge switch KM3 is electrically connected to the connection terminal KM22 of the second electrical equipment.

[0074] The power-on process in this example implementation is as follows: First, close the second switching device KM2, then close the pressure relief precharge switch KM3 at the first selection contact KM31, so that the battery module DC is connected to the capacitive power device SB and the pressure relief precharge load R1, and precharge the first power device connection terminal KM12, that is, first connect the negative terminal of the battery module DC and then connect the positive terminal of the battery module DC. The capacitive power device SB of the circuit is grounded first to avoid unexpected situations. When the Battery Management System (BMS) detects that the voltage between the first electrical device connection terminal KM12 and the second electrical device connection terminal KM22 is close to the DC voltage of the battery pack, specifically, when the BMS detects that the voltage between the first electrical device connection terminal KM12 and the second electrical device connection terminal KM22 is greater than or equal to 90% of the DC voltage of the battery pack, for example, when the BMS detects that the voltage between the first electrical device connection terminal KM12 and the second electrical device connection terminal KM22 is 93%, 95%, or 97.5% of the DC voltage of the battery pack, the first switching device KM1 is closed, and then the pre-charge switch KM3 is closed at the third selection contact KM33 or the pre-charge switch KM4 is opened to complete the power-on process.

[0075] The power-down process is as follows: First, disconnect the first switching device KM1, then disconnect the second switching device KM2. The capacitive device SB is disconnected from the battery pack DC to complete the power-down. That is, the positive terminal of the battery pack DC is disconnected first, and then the negative terminal of the battery pack DC is disconnected, so that the circuit is always grounded before disconnection to avoid accidents. Then, the pressure relief precharge switch KM3 is closed at the second selection contact KM32, so that the capacitive device SB is connected to the pressure relief precharge load R1. The pressure relief precharge load R1 can consume the charge stored in the capacitive device SB. When the battery management system BMS detects that the voltage between the first device connection terminal KM12 and the second device connection terminal KM22 is basically 0, the second selection contact KM32 of the pressure relief precharge switch KM3 is opened (closing it to the normally closed contact) to complete the pressure relief.

[0076] In addition, setting a second switching device KM2 can ensure the normal operation of the power-down process. For example, if the first switching device KM1 is damaged and cannot be disconnected, the power-down process can be achieved by disconnecting the second switching device KM2.

[0077] As illustrated in the above example embodiment, when the pressure relief circuit 10 may include a pre-charge switch KM4 and / or a second switching device KM2, that is, when the pressure relief circuit 10 may include a pre-charge switch KM4 and a second switching device KM2, the pressure relief circuit 10 may also include either a pre-charge switch KM4 or a second switching device KM2. The following description uses the example of the pressure relief circuit 10 including a pre-charge switch KM4 and a second switching device KM2.

[0078] Both the second switching device KM2 and the precharge switch KM4 are relays, so that both the second switching device KM2 and the precharge switch KM4 have two coil terminals, and the coil terminals of the second switching device KM2 and the precharge switch KM4 are their respective control terminals.

[0079] The second switching device KM2 and the precharge switch KM4 can also be contactors. Of course, in some other example embodiments of this disclosure, the second switching device KM2 and the precharge switch KM4 can also be other switching devices with similar functions, which will not be described one by one here.

[0080] Reference Figure 3 As shown, the Battery Management System (BMS) is also electrically connected to the control terminals of the second switching device KM2 and the precharge switch KM4. Specifically, the BMS has a third output interface DO3, a fourth output interface DO4, a seventh output interface DO7, and an eighth output interface DO8. The third output interface DO3 and the fourth output interface DO4 can be electrically connected one-to-one to the two coil terminals of the second switching device KM2, and the seventh output interface DO7 and the eighth output interface DO8 can be electrically connected one-to-one to the two coil terminals of the precharge switch KM4. The BMS can control the closing or opening of the second switching device KM2 and the precharge switch KM4.

[0081] In this case, the battery management system (BMS) is electrically connected to the second electrical device connection terminal KM22 of the second switching device KM2. Specifically, the second input interface DI2 of the battery management system (BMS) can be electrically connected to the second electrical device connection terminal KM22. The battery management system (BMS) can collect the voltage of the first electrical device connection terminal KM12 and the second electrical device connection terminal KM22, and then use the collected voltage to control the closing or opening of the first switching device KM1 and the pressure relief precharge switch KM3, the second switching device KM2 and the precharge switch KM4.

[0082] The Battery Management System (BMS) has a third input interface DI3, which can be electrically connected to the second electrical device connection terminal KM22. The BMS can collect the voltage at the second electrical device connection terminal KM22, and then use the collected voltage to control the closing or opening of the first switching device KM1, the second switching device KM2, and the pressure relief pre-charge switch KM3 and pre-charge switch KM4.

[0083] Optionally, as needed, the Battery Management System (BMS) can be electrically connected to the second battery connection terminal KM21. Specifically, the BMS can have a third input interface DI3, which can be electrically connected to the second battery connection terminal KM21, allowing the BMS to collect the voltage of the second battery connection terminal KM21. Alternatively, the BMS can be electrically connected to the first battery connection terminal KM11. Specifically, the BMS can have a fourth input interface DI4, which can be electrically connected to the first battery connection terminal KM11, allowing the BMS to collect the voltage of the first battery connection terminal KM11.

[0084] Of course, in some other example embodiments of this disclosure, the second switching device KM2 and the precharge switch KM4 can be manual switches. In this case, the battery management system (BMS) may not be provided, or the battery management system (BMS) may be provided, but the second switching device KM2 and the precharge switch KM4 may not be electrically connected to the battery management system (BMS).

[0085] In some exemplary embodiments of this disclosure, reference is made to Figure 1 and Figure 2 As shown, the pressure relief circuit 10 may further include a fuse FU1, which is electrically connected between the battery module DC and the first switching device KM1. Specifically, the fuse FU1 is electrically connected between the battery module DC and the first battery connection terminal KM11. In the event of a short circuit, the fuse FU1 will melt due to the large current flowing through it generating significant heat. Therefore, the fuse FU1 ensures the safety of the power system.

[0086] In this example implementation, refer to Figure 1 and Figure 2 As shown, the pressure relief circuit 10 may further include a charging switch KM5 device, which is electrically connected between the charging interface CD and the positive terminal of the battery pack DC. Specifically, the charging switch KM5 device is electrically connected between the charging interface CD and the first battery connection terminal KM11. The charging interface CD is also electrically connected to the negative terminal of the battery pack DC. Specifically, the charging interface CD is also electrically connected to the second electrical device connection terminal KM22. When the battery pack DC needs to be charged, the charging switch KM5 device and the second switch KM2 device are closed, so that the battery pack DC and the charging interface CD are connected to conduct, thereby realizing the charging of the battery pack DC.

[0087] Based on the same inventive concept, this disclosure provides a power supply system, with reference to... Figure 1 and Figure 2As shown, the power system may include a battery module DC, a capacitive power device SB, and a pressure relief circuit 10; the pressure relief circuit 10 is any of the pressure relief circuits described above, and the pressure relief circuit 10 is electrically connected between the battery module DC and the capacitive power device SB. The specific structure of the pressure relief circuit 10 has been described in detail above, and therefore will not be repeated here.

[0088] In this example embodiment, the battery assembly DC may include one, two, or more lithium batteries. Two lithium batteries may be connected in series or in parallel; multiple lithium batteries may be connected in series or in parallel, or a combination of series and parallel connections. Lithium batteries are widely used due to their advantages such as high energy density, long cycle life, environmental friendliness, no memory effect, high open-circuit voltage, wide operating temperature range, fast charging and discharging speed, and light weight.

[0089] Of course, in some other example embodiments of this disclosure, the battery assembly DC may also include nickel-cadmium batteries, nickel-metal hydride batteries, lead-acid batteries, and so on.

[0090] Compared with the prior art, the beneficial effects of the power supply system provided by the exemplary embodiments of the present invention are the same as the beneficial effects of the pressure relief circuit 10 provided by the above exemplary embodiments, and will not be repeated here.

[0091] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A pressure relief circuit, electrically connected between a battery pack and a capacitive electrical device, characterized in that, The pressure relief circuit includes: A first switching device includes a first battery connection terminal and a first electrical device connection terminal. The first battery connection terminal is electrically connected to the positive terminal of the battery assembly, and the first electrical device connection terminal is electrically connected to one end of the capacitive electrical device. The other end of the capacitive electrical device is electrically connected to the negative terminal of the battery assembly. The device includes a pressure relief precharge switch and a pressure relief precharge load. The pressure relief precharge switch has at least two selection contacts, including a first selection contact and a second selection contact. The first selection contact is connected in series with the pressure relief precharge load and then connected in parallel with the first switching device. The second selection contact is electrically connected to the negative terminal of the battery assembly.

2. The pressure relief circuit according to claim 1, characterized in that, The pressure relief pre-charge switch has two selection contacts, the first selection contact being a normally closed contact, and the pressure relief circuit further includes: The precharge switch is connected in series with the first selection contact and the pressure relief precharge load.

3. The pressure relief circuit according to claim 1, characterized in that, The pressure relief precharge switch also includes a third selection contact, which is a normally closed selection contact and is an unused contact.

4. The pressure relief circuit according to claim 1, characterized in that, The pressure relief circuit also includes: The second switching device includes a second battery connection terminal and a second electrical device connection terminal. The second battery connection terminal is electrically connected to the negative terminal of the battery assembly, the second electrical device connection terminal is electrically connected to the capacitive electrical device, and the second selection contact is electrically connected to the second electrical device connection terminal.

5. The pressure relief circuit according to any one of claims 1 to 4, characterized in that, The first switching device and the pressure relief precharge switch are relays.

6. The pressure relief circuit according to claim 5, characterized in that, The pressure relief circuit also includes: The battery management system is electrically connected to the control terminal of the first switching device and the control terminal of the pressure relief precharge switch, and is also electrically connected to the connection terminal of the first electrical device and the negative terminal of the battery assembly.

7. The pressure relief circuit according to claim 6, characterized in that, When the pressure relief circuit includes a precharge switch and / or a second switching device, the precharge switch and / or the second switching device is a relay.

8. The pressure relief circuit according to claim 7, characterized in that, The battery management system is also electrically connected to the control terminal of the precharge switch and / or the control terminal of the second switching device, and electrically connected to the second electrical equipment connection terminal of the second switching device.

9. The pressure relief circuit according to claim 1, characterized in that, The pressure relief circuit also includes: A fuse is electrically connected between the battery assembly and the first switching device.

10. A power supply system, characterized in that, include: Battery components; Capacitive electrical equipment; The pressure relief circuit is the pressure relief circuit according to any one of claims 1 to 9, wherein the pressure relief circuit is electrically connected between the battery assembly and the capacitive electrical device.

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