Pre-charging circuit and energy storage equipment

Abstract

The utility model provides a pre-charging circuit and an energy storage device. According to the utility model, at least two pre-charging resistors with different resistance values are arranged, and a plurality of switch states are configured, so that when the bus voltage fluctuates or is abnormal, the pre-charging resistors with different resistance values can be selected to be connected to the bus according to the actual condition of the input voltage, thereby realizing the adaptive switching of the charging resistors. According to the design, the problem that a charging resistor of a traditional pre-charging circuit is easy to burn down under the condition that the input voltage is unstable is effectively solved. When the voltage detection module detects that the input voltage is abnormal, the control module switches different resistors and adjusts the charging current to avoid resistor damage caused by overvoltage or overcurrent, so that the stability of the circuit is remarkably improved, the service life of the charging resistor is remarkably prolonged, and safe and reliable operation of the system in an unstable power supply environment is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to a pre-charging circuit and energy storage equipment. Background Art

[0002] A pre-charge circuit typically consists of a fixed-value resistor and a switching device. It's used to limit transient current during system startup, preventing excessive current surges on equipment. By connecting a pre-charge resistor in series, this circuit limits the current to a safe level, allowing loads like capacitors to charge gradually until the system reaches a stable operating voltage before fully connecting to the main current path.

[0003] In the related art, there is a technical problem that the pre-charging circuit is easily damaged. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and provide a pre-charging circuit and an energy storage device to solve the technical problem in the related art that the pre-charging circuit is easily damaged.

[0005] In order to achieve the above technical purpose, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a pre-charging circuit, the circuit comprising:

[0007] A voltage detection module, one end of which is connected to the busbar and is used to detect the voltage signal flowing through the busbar;

[0008] A pre-charging module comprising at least two selectable pre-charging resistors having different resistance values; wherein the pre-charging module is configured with multiple switch states such that when one of the pre-charging resistors is connected to the bus, the remaining pre-charging resistors are disconnected from the bus;

[0009] The control module has a signal input end connected to the other end of the voltage detection module and a signal output end connected to the signal input end of the pre-charging module, and is used to control the switching state of the pre-charging module.

[0010] Furthermore, the pre-charging module further includes:

[0011] At least two first switching devices correspond one-to-one to the at least two selectable pre-charging resistors with different resistance values, and the first switching devices are connected in series with the corresponding pre-charging resistors so that the pre-charging resistors can be selectively connected to the bus or disconnected from the bus.

[0012] Furthermore, the circuit includes:

[0013] A second switching device is configured on the busbar and connected in parallel with the pre-charging module, one end of which is connected to the first end of the pre-charging module, and the other end of which is connected to the second end of the pre-charging module; wherein the first end of the pre-charging module is the current inflow end, and the second end is the current outflow end.

[0014] Furthermore, the pre-charging module further includes:

[0015] A current detection device, one end of which is connected to the busbar and the other end is connected to the input end of the pre-charging resistor, is used to detect the current signal flowing through the pre-charging resistor.

[0016] Furthermore, the pre-charging module further includes:

[0017] A fuse device is provided between the current detection device and the input end of the pre-charging resistor.

[0018] Furthermore, the voltage detection module includes:

[0019] a first voltage-dividing resistor, one end of which is connected to the positive busbar of the busbar;

[0020] a second voltage-dividing resistor, one end of which is connected to the negative busbar of the busbar;

[0021] an operational amplifier, wherein a positive input terminal of the operational amplifier is connected to the other end of the first voltage-dividing resistor, a negative input terminal of the operational amplifier is connected to the other end of the second voltage-dividing resistor, and an output terminal of the operational amplifier is connected to the control module;

[0022] A reference voltage resistor has one end connected to the ground and the other end connected to a connection point between the second voltage divider resistor and the operational amplifier.

[0023] Furthermore, the voltage detection module further includes a feedback circuit, and the feedback circuit includes:

[0024] a feedback resistor, one end of which is connected to the positive input terminal of the operational amplifier, and the other end of which is connected to the output terminal of the operational amplifier;

[0025] A first filter capacitor is connected in parallel with the feedback resistor.

[0026] Furthermore, the voltage detection module further includes:

[0027] A second filter capacitor has one end connected to the ground, and the other end connected to a connection point between the second voltage-dividing resistor and the operational amplifier.

[0028] Furthermore, the pre-charging resistor is a resistor with a fixed resistance or a resistor with a variable resistance.

[0029] In a second aspect, the present invention provides an energy storage device, which includes the above-mentioned pre-charging circuit.

[0030] Beneficial effects:

[0031] The present invention sets at least two pre-charging resistors with different resistance values ​​and configures multiple switch states. When the bus voltage fluctuates or is abnormal, pre-charging resistors with different resistance values ​​can be selected according to the actual situation of the input voltage to connect to the bus, thereby realizing adaptive switching of the charging resistors. This design effectively solves the problem that the charging resistors of the traditional pre-charging circuit are easily burned when the input voltage is unstable. When the voltage detection module detects that the input voltage is abnormal, the control module switches different resistors and adjusts the charging current to avoid damage to the resistors caused by overvoltage or overcurrent, thereby significantly improving the stability of the circuit and the service life of the charging resistors, ensuring the safe and reliable operation of the system in an unstable power supply environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a module schematic diagram of a pre-charging circuit provided by an embodiment of the present utility model;

[0033] Figure 2 This is a module schematic diagram of a pre-charging circuit provided by an embodiment of the present utility model;

[0034] Figure 3 This is a module schematic diagram of a pre-charging circuit provided by an embodiment of the present utility model;

[0035] Figure 4 This is a circuit diagram of a pre-charging circuit used in an embodiment of the present utility model.

[0036] In the accompanying drawings: voltage detection module-100, pre-charging module-200, control module-300, first switching device-201, pre-charging resistor-202, second switching device-400. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0038] In the related art, in power systems and energy storage devices, pre-charging circuits are key components used to avoid instantaneous large current shocks by gradually increasing the input voltage when the device starts, thereby protecting the core circuits of the device. The working principle of the pre-charging circuit can be to achieve initial current limiting through charging resistors, thereby smoothly charging the capacitors inside the system. This process is particularly important in applications where direct current (DC) power is converted to alternating current (AC). For example, in UPS systems, energy storage devices, and electric vehicle charging systems, pre-charging circuits are often used to protect the system from being impacted by inrush currents. However, pre-charging circuits are easily damaged by overvoltage or voltage fluctuations.

[0039] During the pre-charge process, the system often faces a complex and unstable operating environment, especially when the grid voltage is unstable or the power input fluctuates dramatically. The input voltage can fluctuate dramatically in a short period of time, causing the pre-charge circuit to experience undervoltage shutdown or overvoltage shock during startup. For example, during the pre-charge process, if the input voltage suddenly drops below the minimum starting voltage required by the system, the system will shut down due to undervoltage. However, once the input voltage recovers and reaches the starting voltage, the pre-charge process will automatically restart. This frequent start-stop cycle can adversely affect the charging resistor during the pre-charge process. Furthermore, if the input voltage suddenly rises to an overvoltage state during the pre-charge process, the pre-charge resistor will be subjected to an instantaneous excessive current, potentially burning out the resistor. Frequent overcurrent and overvoltage events not only directly affect the service life of the pre-charge resistor but can also further affect the reliability of the entire circuit, causing system failure.

[0040] In related technologies, pre-charge circuits lack effective overvoltage and overcurrent protection mechanisms. The pre-charge resistor operates with a single fixed resistance, unable to adapt to varying current demands caused by input voltage fluctuations. This single configuration is particularly vulnerable to drastic input voltage fluctuations, and the fixed resistance value makes it difficult to cope with sudden overvoltage or overcurrent conditions, which can easily burn out the charging resistor.

[0041] like Figure 1 、 Figure 2 as well as Figure 3 As shown, in this embodiment, a pre-charging circuit is provided, and the circuit may include:

[0042] The voltage detection module 100 has one end connected to the busbar and is used to detect the voltage signal flowing through the busbar.

[0043] In this embodiment, the voltage detection module 100 may be composed of a voltage-dividing resistor and an operational amplifier. Specifically, the voltage-dividing resistor divides the bus voltage to within the input range of the operational amplifier. The operational amplifier may be configured as a differential amplifier to detect the voltage difference on the bus and output a proportional signal. This output signal may reflect the instantaneous value of the bus voltage and is provided to the control module 300 for evaluation.

[0044] In this embodiment, the voltage detection module 100 can also be a voltage comparator circuit. Specifically, the voltage comparator circuit may include a comparator, a reference voltage source, and a voltage divider resistor. The voltage comparator has two input terminals, which are respectively connected to the reference voltage source and the voltage divider signal of the bus voltage. During operation, the bus voltage is connected to the input terminal of the comparator through the voltage divider resistor, and the other input terminal is connected to a fixed reference voltage source. When the bus voltage exceeds the reference voltage, the comparator outputs a high-level signal; when the bus voltage is lower than the reference voltage, it outputs a low-level signal. In this way, the control module 300 can determine in real time whether the voltage is within the normal range.

[0045] In this embodiment, the voltage detection module 100 may also be composed of a voltage-dividing resistor and an integrated ADC (analog-to-digital converter) chip. Specifically, the bus voltage is reduced to within the input range of the ADC chip via the voltage-dividing resistor. The ADC chip then converts the divided analog voltage signal into a digital signal. The control module 300 can directly read this digital signal to accurately determine the bus voltage value and perform control as needed.

[0046] In this embodiment, the voltage detection module 100 may also be an isolated optocoupler voltage detection circuit.

[0047] In this embodiment, the busbar may be a DC busbar or an AC busbar.

[0048] A pre-charging module 200 includes at least two selectable pre-charging resistors 202 with different resistance values; wherein the pre-charging module 200 is configured with multiple switching states so that when one of the pre-charging resistors 202 is connected to the bus, the remaining pre-charging resistors 202 are disconnected from the bus.

[0049] In this embodiment, the pre-charging module 200 may be configured with multiple pre-charging resistors 202 with different resistance values. The multiple pre-charging resistors 202 with different resistance values ​​are connected in parallel. The multiple pre-charging resistors 202 with different resistance values ​​may be two, three, or more pre-charging resistors 202.

[0050] In this embodiment, the selection may be represented by the pre-charging resistor 202 in the pre-charging module 200 being connectable to the bus or disconnectable from the bus.

[0051] In this embodiment, the pre-charging module 200 is configured with multiple switch states, which can be represented by the pre-charging module 200 having multiple different switch states. These switch states allow the pre-charging module 200 to switch between pre-charging resistors 202 with different resistance values. Specifically, when the pre-charging module 200 selects to connect one pre-charging resistor 202 to the bus, the other pre-charging resistors 202 will be automatically disconnected (i.e., not connected to the bus).

[0052] In this embodiment, through this switch configuration, the pre-charge module 200 can select pre-charge resistors 202 of different resistance values ​​to connect to the bus to meet the current and voltage requirements. This design provides flexible current control capabilities and can achieve adaptive adjustment by switching the resistance value in the event of power supply voltage fluctuations or load changes, thereby protecting the circuit and improving system stability.

[0053] In this embodiment, the pre-charging module 200 may include a plurality of pre-charging resistors 202 connected in parallel. Each pre-charging resistor 202 is connected in series with a switching device. The switching device is used to control whether the pre-charging resistor 202 is connected to or disconnected from the busbar. Therefore, in this embodiment, the pre-charging module 200 can be configured with multiple switching states through this circuit structure, so that when one of the pre-charging resistors 202 is connected to the busbar, the remaining pre-charging resistors 202 are disconnected from the busbar.

[0054] In this embodiment, the pre-charging module 200 may also adopt a multi-way switch selector circuit structure. Specifically, a multi-way selector switch may be used, each input end of which is connected to a pre-charging resistor 202, and the output end of which is connected to the bus. The control module 300 controls the multi-way selector switch so that when the pre-charging module 200 is in operation, only one pre-charging resistor 202 is connected to the bus at any time, while the other pre-charging resistors 202 are disconnected.

[0055] In this embodiment, the pre-charging module 200 may also adopt the following circuit structure. Specifically:

[0056] The first ends of all pre-charge resistors 202 are connected to the busbar, providing different current-limiting resistance values ​​when the busbar is initially powered on. The second ends of all pre-charge resistors 202 are connected to ground via a common switch. This switch has multiple channels, each of which is connected to the second end of a pre-charge resistor 202. The output end of the switch is connected to the circuit ground.

[0057] The control module 300300 selects the appropriate pre-charge resistor 202 channel based on the actual bus voltage, gradually connecting pre-charge resistors 202 of different resistance values ​​to the current path. For example, when the bus is first powered on, the control module 300 will select the appropriate channel, close the first channel, and connect the second end of the first pre-charge resistor 202 to the ground point to gradually charge the system capacitor. At the same time, the other channels remain disconnected. After the voltage rises steadily and reaches the startup threshold, the control module 300 will disconnect all channels, ending the pre-charge process and directly connecting the bus to the main circuit.

[0058] In this embodiment, the pre-charge module 200 is designed with at least two pre-charge resistors 202 with different resistance values, and the difference in resistance values ​​provides flexible options for the circuit under different voltage states. Different resistance values ​​correspond to different pre-charge currents, so as to adapt to the current power supply state when the input voltage is higher or lower, and protect the circuit safety. Selectably means that the control module 300 can dynamically select a suitable resistor among multiple resistors to access the bus according to system requirements. For example, when it is detected that the input voltage is low, the control module 300 can select a pre-charge resistor 202 with a smaller resistance value to access the bus to ensure that the system still obtains sufficient charging current under low voltage conditions. When the input voltage rises to a normal level, the control module 300 can select a pre-charge resistor 202 with a larger resistance value to reduce the pre-charge current and prevent overcurrent damage.

[0059] The control module 300 has a signal input end connected to the other end of the voltage detection module 100 and a signal output end connected to the signal input end of the pre-charging module 200 , and is used to control the switching state of the pre-charging module 200 .

[0060] In this embodiment, the control module 300 can be connected to the voltage detection module 100 and the pre-charge module 200, respectively. Specifically, the signal input terminal of the control module 300 can be connected to the other terminal of the voltage detection module 100. The other terminal of the voltage detection module 100 can be represented as the signal output terminal of the voltage detection module 100. It is understood that one terminal of the voltage detection module 100 is connected to the busbar and can detect the voltage signal flowing through the busbar. The other terminal of the voltage detection module 100 inputs the detected voltage signal into the control module 300.

[0061] The signal output terminal of the control module 300 is connected to the signal input terminal of the pre-charging module 200. It is understandable that the signal input terminal of the pre-charging module 200 can be the signal input terminal of the switch device in the pre-charging module 200.

[0062] In this embodiment, the control module 300 may be a microcontroller (MCU). It is understood that a microcontroller is an embedded controller with integrated ADC, PWM output, communication interface (e.g., I2C, SPI, UART) and other functions, capable of receiving the electrical signal transmitted by the voltage detection module 100 and controlling the on / off state of the pre-charging module 200.

[0063] In this embodiment, the controller may be a digital signal processor (DSP).

[0064] In this embodiment, the controller may be a field programmable gate array (FPGA). It is understood that a field programmable gate array is a hardware programmable logic device capable of parallel processing. A field programmable gate array can perform ultra-high-speed data acquisition and control operations.

[0065] In this embodiment, the controller may also be an application specific integrated circuit (ASIC).

[0066] In this embodiment, the controller may also be an embedded system. For example, the embedded system may be an embedded system based on a Linux operating system.

[0067] In this embodiment, by setting at least two pre-charging resistors 202 with different resistance values ​​and configuring multiple switch states, when the bus voltage fluctuates or is abnormal, pre-charging resistors 202 with different resistance values ​​can be selected according to the actual situation of the input voltage to connect to the bus, thereby realizing adaptive switching of the charging resistor. Such a design effectively solves the problem that the charging resistor of the traditional pre-charging circuit is easy to burn out when the input voltage is unstable. When the voltage detection module 100 detects that the input voltage is abnormal, the control module 300 adjusts the charging current by switching different resistors to avoid damage to the resistor caused by overvoltage or overcurrent, thereby significantly improving the stability of the circuit and the service life of the charging resistor, ensuring the safe and reliable operation of the system in an unstable power supply environment.

[0068] Workflow:

[0069] 1. Initial detection and pre-charge startup:

[0070] When the busbar is initially powered, the voltage detection module 100 detects the busbar voltage and transmits a signal to the control module 300. The control module 300 determines whether the input voltage has reached the threshold voltage required for the appliance to start. If the input voltage is below the threshold, the appliance remains off, and neither the pre-charge module 200 nor the main circuit is connected. Upon detecting that the input voltage has reached the startup voltage threshold, the control module 300 initiates the pre-charge process.

[0071] 2. Normal pre-charging process:

[0072] The control module 300 closes the first switch state of the pre-charge module 200, connecting the smaller pre-charge resistor 202 to the busbar. This resistor forms a current-limiting path with the busbar capacitor, gradually charging the system. During this phase, the pre-charge resistor 202 controls the initial charging current to protect the system from high current surges. The voltage detection module 100 continuously monitors the busbar voltage and provides feedback to the control module 300 until the busbar voltage gradually approaches the full system voltage.

[0073] 3. Main circuit connected:

[0074] When the bus voltage reaches a stable operating voltage (i.e., full system voltage) sufficient to drive the electrical loads, the control module 300 disconnects the pre-charge resistor 202 and connects the bus directly to the main current path of the electrical loads. During this process, all switches in the pre-charge module 200 are disconnected, ending the pre-charge phase and allowing the electrical loads to resume normal operation.

[0075] 4. Emergency protection caused by voltage fluctuations:

[0076] If the voltage detection module 100 detects a dramatic bus voltage fluctuation during electrical operation—for example, if the input voltage exceeds the normal operating voltage (overvoltage) or suddenly drops below the set undervoltage threshold—the control module 300 immediately enters a protection state. The control module 300 disconnects all pre-charge modules 200 and disconnects the pre-charge resistor 202 to prevent the resistor from burning out due to overcurrent. The control module 300 also switches the main circuit of the appliance to a closed state, putting the system into standby mode to prevent damage.

[0077] 5. Pre-charge resistor 202 switching protection (adaptive switching):

[0078] During the pre-charging phase, if the input voltage is detected to have suddenly risen beyond the safe range of the current pre-charging resistor 202 (overvoltage condition), the control module 300 will disconnect the current pre-charging resistor 202 (the pre-charging resistor 202 with a smaller resistance) and switch to the pre-charging resistor 202 with a larger resistance to access the current path. The pre-charging resistor 202 with a larger resistance limits the charging current, preventing the pre-charging resistor 202 with a smaller resistance from being damaged by overcurrent. The control module 300 will continue to monitor the voltage. If the voltage returns to normal, it can switch back to the pre-charging resistor 202 with a smaller resistance to continue the pre-charging process.

[0079] 6. Overcurrent protection:

[0080] In some embodiments, the pre-charging module 200 may also be configured with a current sensor. During the pre-charging process, if the current sensor detects that the current on the pre-charging resistor 202 exceeds a safe value (overcurrent), the control module 300 will immediately cut off all switches, terminating the pre-charging process. After the overcurrent or overvoltage condition is resolved and the bus voltage returns to normal, the control module 300 restarts the pre-charging process, connecting the pre-charging resistor 202 in sequence, and gradually completing the system power-up.

[0081] like Figure 2 As shown, in some embodiments, the pre-charging module 200 further includes:

[0082] At least two first switching devices 201201, the at least two first switching devices 201 correspond one-to-one to the at least two pre-charging resistors 202202 that can be selected and have different resistance values, the first switching device 201 is connected in series with the corresponding pre-charging resistor 202 so that the pre-charging resistor 202 can be selectively connected to the bus or disconnected from the bus.

[0083] In this embodiment, the one-to-one correspondence between the at least two first switching devices 201 and the at least two pre-charging resistors 202 that can be selected and have different resistance values ​​can be expressed as the number and position of the first switching devices 201 and the number and position of the pre-charging resistors 202 are in one-to-one correspondence. For example, if three pre-charging resistors 202 are provided in the pre-charging module 200, correspondingly, three first switching devices 201 also need to be provided. And one first switching device 201 is connected to one pre-charging resistor 202. It cannot be that the three first switching devices 201 are only connected to one pre-charging resistor 202, and the other two pre-charging resistors 202 have no connection with the switching device. Therefore, the at least two first switching devices 201 correspond one-to-one to the at least two pre-charging resistors 202 that can be selected and have different resistance values.

[0084] Furthermore, the connection is a series connection rather than a parallel connection, because the series connection is required to control whether the corresponding pre-charging resistor 202 is connected to the bus.

[0085] In this embodiment, the first switching device 201 may be a relay. It is understood that a relay is an electrical control device that uses electromagnetic principles to automatically control a switch. A relay may consist of a coil, contacts, and a spring. When the coil is energized, the generated magnetic field attracts the contacts, connecting or disconnecting the circuit.

[0086] The control module 300 can send control signals to the relays in the pre-charge module 200 to control the on / off status of each relay. When the signal is sent, the coil of the target relay is energized, the contacts are closed, and the pre-charge resistor 202 corresponding to the target relay is connected to the busbar. The remaining pre-charge resistors 202 need to be disconnected from the busbar.

[0087] In this embodiment, the first switching device 201 can be a MOSFET. Specifically, the source of each MOSFET is connected to the corresponding pre-charge resistor 202, and the drain is connected to the bus or the load to achieve series connection of the pre-charge resistor 202. Under this connection mode, the MOSFET controls whether the pre-charge resistor 202 is turned on or off, thereby controlling whether the pre-charge resistor 202 is connected to the bus. The control module 300 is connected to the gate of the MOSFET through its signal output terminal to control the switching state of the MOSFET. When the control signal causes the gate voltage to rise to the turn-on threshold, the MOSFET is turned on and the corresponding pre-charge resistor 202 is connected to the circuit. By controlling the gate voltage, the control module 300 can selectively turn on or off the pre-charge resistor 202 corresponding to each MOSFET to achieve gradual current limiting or adaptive adjustment.

[0088] In this embodiment, the first switching device 201 may be an IGBT. Specifically, the collector of the IGBT is connected to the corresponding pre-charging resistor 202, and the emitter is connected to the bus or the load. The IGBT acts as a switch to control whether the pre-charging resistor 202 is connected or not to prevent overcurrent or high current shock. The signal output end of the control module 300 is connected to the gate of the IGBT, and the control module 300 adjusts the conduction state of the IGBT by outputting a drive signal to the gate. When the gate voltage exceeds the conduction threshold, the IGBT is turned on, the corresponding pre-charging resistor 202 is connected to the bus, and the other IGBTs and pre-charging resistors 202 that are not connected are in the disconnected state.

[0089] In this embodiment, the first switching device 201 may also be a solid-state relay.

[0090] In this embodiment, the first switching device 201 may also be an electronic switch.

[0091] This embodiment provides a plurality of pre-charge resistors 202 with different resistance values ​​in the pre-charge module 200, and connects each resistor in series with a corresponding first switching device 201. Pre-charge resistors 202 with different resistance values ​​can be selectively connected to the bus according to system requirements, thereby achieving precise current control and voltage adaptive adjustment. In the event of power supply voltage fluctuations or changes in load conditions, by switching between different pre-charge resistor 202 values, damage to the resistor caused by transient overcurrent or overvoltage is avoided, significantly improving the stability and service life of the pre-charge circuit and ensuring safe and reliable operation of the system in an unstable power supply environment.

[0092] like Figure 3 As shown, in some embodiments, the circuit includes:

[0093] The second switching device 400 is configured on the bus and is connected in parallel with the pre-charging module 200, one end of which is connected to the first end of the pre-charging module 200, and the other end of which is connected to the second end of the pre-charging module 200; wherein the first end of the pre-charging module 200 is the current inflow end, and the second end is the current outflow end.

[0094] In this embodiment, the second switching device 400 is configured on the bus and is connected in parallel with the pre-charging module 200. The second switching device 400 can be used to control the second switching device 400 to disconnect when the pre-charging program needs to be executed, and the control module 300 sends a control signal to the signal input terminal of the second switching device 400. To control the second switching device 400 to disconnect. And send a control signal to each first switching device 201 in the pre-charging module 200, so that the target pre-charging resistor 202 is connected to the bus, and the remaining pre-charging resistors 202 are disconnected. Accordingly, when the pre-charging program ends, the control module 300 can control all the first switching devices 201 to disconnect, and control the second switching device 400 to close. Correspondingly, when the voltage detection module 100 detects overvoltage, it can control all the first switching devices 201 and the second switching devices 400 to disconnect to protect the circuit.

[0095] It is understandable that when the system is powered on and the voltage detection module 100 detects that the bus voltage is within the starting range, the control module 300 starts the pre-charging procedure. The control module 300 sends a signal to the control end of the second switching device 400 to put it in an off state. At this time, the current cannot flow directly into the main circuit through the second switching device 400. The control module 300 selects and closes a first switching device 201 in the pre-charging module 200, so that the target pre-charging resistor 202 is connected to the bus current path, while disconnecting the other pre-charging resistors 202. In this way, the current flows into the bus through the selected pre-charging resistor 202, gradually limiting the current and charging to avoid large current shocks to the system. During the pre-charging stage, the voltage detection module 100 continuously monitors the rise in bus voltage. If voltage fluctuations are detected or the charging speed needs to be adjusted, the control module 300 can selectively disconnect the switch device of the current pre-charging resistor 202 and connect another pre-charging resistor 202 with a more appropriate resistance value, thereby providing a more accurate current limiting effect. During the entire process, the second switching device 400 remains disconnected, and all currents flow through the pre-charging resistor 202 , thereby limiting the current inflow speed and protecting the back-end equipment.

[0096] At the end of the pre-charge process, the bus voltage stabilizes within the system's target range, indicating that the system can withstand the main current load. The control module 300 sends a signal to the second switching device 400 to close it, thereby directly connecting the bus to the main current path. At this point, current bypasses the pre-charge module 200 and flows directly to the main load, ensuring efficient power supply to the circuit. The control module 300 disconnects the first switching devices 201 of all pre-charge resistors 202, completely disengaging the pre-charge module 202. This prevents the pre-charge resistors 202 from carrying the main load current and prolongs the resistor life. If the system detects that the input voltage exceeds the safe range during the pre-charge process or normal operation, an overvoltage risk may occur. The control module 300 immediately sends a disconnect command to the second switching device 400 and all first switching devices 201, completely isolating the pre-charge module 200 from the main current path, protecting the circuit and the pre-charge resistors 202 from overvoltage damage. The system enters protection mode, and the control module 300 monitors voltage recovery. When the input voltage returns to a safe range, the control module 300 can restart the pre-charge process and reconnect the circuit according to the above steps.

[0097] In this embodiment, the first end of the pre-charging module 200 may be an end close to the positive pole of the bus bar, and the second end of the pre-charging module 200 may be an end close to the negative pole of the bus bar.

[0098] In this embodiment, the second switching device 400 may be a relay.

[0099] In this embodiment, the second switching device 400 may be a MOSFET.

[0100] In this embodiment, the second switching device 400 may be an IGBT.

[0101] In this embodiment, the second switching device 400 may be a solid-state relay.

[0102] In this embodiment, the second switching device 400 may be an electronic switch.

[0103] This embodiment achieves flexible control of the pre-charging process by configuring a second switching device 400 in parallel on the bus. When pre-charging is started, the second switching device 400 is in the disconnected state, and the current is gradually limited and charged through the pre-charging module 200 to prevent instantaneous large current from impacting the system. When the pre-charging is completed and a stable voltage is reached, the control module 300 can close the second switching device 400 and connect the bus directly to the main circuit, thereby bypassing the pre-charging module 200. This design not only effectively protects the pre-charging resistor 202 from the load of continuous current and extends its service life, but also reduces resistance loss after the system is started, thereby improving the efficiency and operational stability of the entire circuit.

[0104] In some embodiments, the pre-charging module 200 further includes:

[0105] The current detection device has one end connected to the busbar and the other end connected to the input end of the pre-charging resistor 202 , and is used to detect the current signal flowing through the pre-charging resistor 202 .

[0106] In this embodiment, the input end of the pre-charging resistor 202 may be the first end of the pre-charging module 200 , that is, the current input end. The signal output end of the current detection device may be connected to the signal input end of the control module 300 .

[0107] In this embodiment, the current detection device may be a Hall effect sensor.

[0108] In this embodiment, the current detection device may be a current transformer.

[0109] In this embodiment, the current detection device may be an optocoupler isolation current sensor.

[0110] This embodiment, by adding a current detection device to the pre-charging module 200, can monitor the current signal flowing through the pre-charging resistor 202 in real time to ensure that the charging current is within a safe range. When the current detection device detects an abnormally large current, the control module 300 can take timely measures, such as switching to a pre-charging resistor 202 with a higher resistance value or directly disconnecting the pre-charging circuit to prevent overcurrent from damaging the resistor and other circuit components. This design enhances the current control accuracy and protection capabilities of the system during the pre-charging process, effectively extends the service life of the pre-charging resistor 202 and related components, and improves the safety and stability of the system.

[0111] In some embodiments, the pre-charging module 200 further includes:

[0112] A fuse device is provided between the current detection device and the input end of the pre-charging resistor 202 .

[0113] In this example, the fuse device may be a fuse.

[0114] In this example, the fuse device may be a resettable fuse.

[0115] In this example, the fuse device may be a circuit breaker.

[0116] In this example, the fuse device may be an electronic fuse device.

[0117] This embodiment adds an extra layer of safety protection by placing a fuse between the current sensing device and pre-charge resistor 202. In the event of a sudden overcurrent, the fuse quickly blows, severing the current path and preventing damage to pre-charge resistor 202 and subsequent circuit components. This design also provides redundant protection in the event that the current sensing device fails or fails to detect an overcurrent, significantly improving the reliability and safety of pre-charge module 200 and the overall system.

[0118] In some embodiments, the voltage detection module 100 includes:

[0119] A first voltage-dividing resistor has one end connected to the positive busbar of the busbar.

[0120] A second voltage-dividing resistor has one end connected to the negative busbar of the busbar.

[0121] An operational amplifier, whose positive input terminal is connected to the other end of the first voltage-dividing resistor, whose negative input terminal is connected to the other end of the second voltage-dividing resistor, and whose output terminal is connected to the control module 300.

[0122] A reference voltage resistor has one end connected to the ground and the other end connected to a connection point between the second voltage divider resistor and the operational amplifier.

[0123] This embodiment achieves real-time monitoring of the bus voltage by precisely dividing and amplifying the bus voltage using first and second voltage-dividing resistors and an operational amplifier. The voltage-dividing resistors reduce the bus voltage to within the input range of the operational amplifier, which then precisely amplifies the divided voltage signal and outputs it to the control module 300. The reference voltage resistor provides a stable reference point for voltage detection, ensuring accurate and anti-interference monitoring. In this design, the control module 300 can determine the system status in real time based on accurate voltage feedback, promptly executing pre-charge and overvoltage protection, and enhancing system safety and response accuracy.

[0124] In some embodiments, the voltage detection module 100 further includes a feedback circuit, and the feedback circuit includes:

[0125] a feedback resistor, one end of which is connected to the positive input terminal of the operational amplifier, and the other end of which is connected to the output terminal of the operational amplifier;

[0126] A first filter capacitor is connected in parallel with the feedback resistor.

[0127] This embodiment enhances the accuracy and stability of voltage detection by adding a feedback circuit to the voltage detection module 100. The feedback resistor feeds back part of the output signal of the operational amplifier to the positive input terminal, forming negative feedback, thereby improving the stability and anti-interference ability of the circuit. At the same time, the first filter capacitor connected in parallel with the feedback resistor can effectively filter out high-frequency noise, further smooth the feedback signal, and reduce the detection error caused by voltage fluctuations. This design ensures that the voltage detection module 100 can provide a stable and accurate voltage signal in a complex power supply environment, allowing the control module 300 to more accurately judge the voltage state, thereby optimizing the response effect of pre-charging and overvoltage protection.

[0128] In some embodiments, the voltage detection module 100 further includes:

[0129] A second filter capacitor has one end connected to the ground, and the other end connected to a connection point between the second voltage-dividing resistor and the operational amplifier.

[0130] This embodiment effectively filters out low-frequency noise and voltage fluctuations in the input signal by adding a second filter capacitor to the voltage detection module 100, further improving the stability of voltage detection. The grounding design of the second filter capacitor ensures its noise suppression effect at the connection point between the second voltage divider resistor and the operational amplifier, making the input voltage signal smoother and preventing transient interference signals from affecting the voltage detection accuracy. This design enhances the system's anti-interference ability in complex power supply environments, enabling the control module 300 to make more accurate pre-charge and protection responses based on accurate voltage feedback signals, thereby improving the safety and reliability of the system.

[0131] In some embodiments, the pre-charging resistor 202 is a fixed resistance resistor or a variable resistance resistor.

[0132] In this embodiment, the pre-charge resistor 202 can be configured with a fixed resistance or a variable resistance as required to achieve more flexible current control. Fixed resistance resistors have a simple structure and low cost, and are suitable for environments with stable voltage and current, while variable resistance resistors can dynamically adjust their resistance according to fluctuations in the input voltage, providing a more adaptable current limiting effect. This design is particularly advantageous in cases where the power supply voltage is unstable or the load changes, allowing the system to optimize the pre-charge current under different operating conditions, further improving the safety, stability, and responsiveness of the system.

[0133] like Figure 4 As shown, in a specific embodiment, a pre-charging circuit is provided. The pre-charging circuit may include: a pre-charging module, a voltage detection module and a control module.

[0134] The pre-charge module includes:

[0135] The current detection device U1 has one end connected to the busbar and can be a current transformer.

[0136] A fuse device FU1 is provided between the current detection device U1 and the input end of the pre-charging resistors (R5 and R6). The fuse device FU1 may be a fuse.

[0137] The pre-charge resistor R5 can be a resistor with a relatively large resistance.

[0138] The pre-charge resistor R6 can be a resistor with a relatively small resistance.

[0139] The first switch device S1 is connected in series with the pre-charging resistor R5. One end of the first switch device S1 is connected to the pre-charging resistor R5, and the other end is connected to the bus.

[0140] The first switch device S2 is connected in series with the pre-charging resistor R6. One end of the first switch device S3 is connected to the pre-charging resistor R6, and the other end is connected to the bus.

[0141] The pre-charging circuit further includes a second switching device S3 connected in parallel with the pre-charging module 200. The second switching device S3 is arranged on the bus. The first switching device S1, the first switching device S2 and the second switching device S3 can all be relays.

[0142] The voltage detection module includes:

[0143] A first voltage-dividing resistor R2 has one end connected to the positive busbar of the busbar.

[0144] A second voltage-dividing resistor R3 has one end connected to the negative busbar of the busbar.

[0145] The operational amplifier U2 has a positive input connected to the other end of the first voltage-dividing resistor R2, a negative input connected to the other end of the second voltage-dividing resistor R3, and an output connected to the MCU.

[0146] The reference voltage resistor R4 has one end connected to the ground, and the other end connected to the connection point between the second voltage-dividing resistor R3 and the operational amplifier U2.

[0147] The feedback resistor R1 has one end connected to the positive input terminal of the operational amplifier U2 and the other end connected to the output terminal of the operational amplifier U2.

[0148] A first filter capacitor C1 is connected in parallel with the feedback resistor R1.

[0149] The second filter capacitor C2 has one end connected to the ground, and the other end connected to the connection point between the second voltage-dividing resistor R3 and the operational amplifier U2.

[0150] The control module may be the MCU in the figure.

[0151] An embodiment of the present utility model provides an energy storage device, which includes the above-mentioned pre-charging circuit.

[0152] Specifically, the energy storage device can be an uninterruptible power supply (UPS). A UPS system is used to provide short-term backup power during a power outage. The pre-charge circuit gradually increases the input voltage when power is restored to prevent excessive transient current from impacting components such as capacitors and batteries within the UPS.

[0153] The energy storage device can be an electric vehicle (EV) charging system. As is understandable, the high-voltage battery pack of an EV typically requires precharging when connected to a charging station to prevent high currents from directly impacting the battery system and damaging the battery and power electronics. A precharging circuit can gradually increase the charging current, ensuring that the EV battery pack is connected to the charger in a stable state, thereby improving charging safety and battery life.

[0154] The energy storage device can be a household or industrial energy storage system.

[0155] The energy storage device may also be a photovoltaic (PV) energy storage system.

[0156] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0157] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0158] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0159] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0160] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A pre-charging circuit, characterized in that: The circuit comprises: A voltage detection module, one end of which is connected to the busbar and is used to detect the voltage signal flowing through the busbar; A pre-charging module comprising at least two selectable pre-charging resistors having different resistance values; wherein the pre-charging module is configured with multiple switch states such that when one of the pre-charging resistors is connected to the bus, the remaining pre-charging resistors are disconnected from the bus; The control module has a signal input end connected to the other end of the voltage detection module and a signal output end connected to the signal input end of the pre-charging module, and is used to control the switching state of the pre-charging module.

2. The circuit according to claim 1, wherein: The pre-charging module further includes: At least two first switching devices correspond one-to-one to the at least two selectable pre-charging resistors with different resistance values, and the first switching devices are connected in series with the corresponding pre-charging resistors so that the pre-charging resistors can be selectively connected to the bus or disconnected from the bus.

3. The circuit according to claim 2, characterized in that The circuit comprises: A second switching device is configured on the busbar and connected in parallel with the pre-charging module, one end of which is connected to the first end of the pre-charging module, and the other end of which is connected to the second end of the pre-charging module; wherein the first end of the pre-charging module is the current inflow end, and the second end is the current outflow end.

4. The circuit according to claim 1, wherein: The pre-charging module further includes: A current detection device, one end of which is connected to the busbar and the other end is connected to the input end of the pre-charging resistor, is used to detect the current signal flowing through the pre-charging resistor.

5. The circuit according to claim 4, characterized in that The pre-charging module further includes: A fuse device is provided between the current detection device and the input end of the pre-charging resistor.

6. The circuit according to claim 1, wherein: The voltage detection module includes: a first voltage-dividing resistor, one end of which is connected to the positive busbar of the busbar; a second voltage-dividing resistor, one end of which is connected to the negative busbar of the busbar; an operational amplifier, wherein a positive input terminal of the operational amplifier is connected to the other end of the first voltage-dividing resistor, a negative input terminal of the operational amplifier is connected to the other end of the second voltage-dividing resistor, and an output terminal of the operational amplifier is connected to the control module; A reference voltage resistor has one end connected to the ground and the other end connected to a connection point between the second voltage divider resistor and the operational amplifier.

7. The circuit according to claim 6, characterized in that The voltage detection module further includes a feedback circuit, which includes: a feedback resistor, one end of which is connected to the positive input terminal of the operational amplifier, and the other end of which is connected to the output terminal of the operational amplifier; A first filter capacitor is connected in parallel with the feedback resistor.

8. The circuit according to claim 6, characterized in that The voltage detection module also includes: A second filter capacitor has one end connected to the ground, and the other end connected to a connection point between the second voltage-dividing resistor and the operational amplifier.

9. The circuit according to claim 1, wherein: The pre-charging resistor is a resistor with a fixed resistance or a resistor with a variable resistance.

10. An energy storage device, characterized in that: The energy storage device includes the pre-charging circuit according to any one of claims 1-9.

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