The charging protection circuit and protection device of the portable charger and the portable charger itself.

Abstract

This application provides a charging protection circuit, protection device, and portable charger for a portable charger, relating to the field of electric vehicle charging equipment technology. The circuit includes a voltage conversion unit, a BMS fault latching unit, and an insulation fault latching unit connected in series. The voltage conversion unit outputs a low-voltage DC power supply signal. The BMS fault latching unit receives a BMS status signal, latches it when the signal is a BMS fault signal, and outputs the latched BMS fault signal. The insulation fault latching unit acquires an insulation status signal, latches it when the signal is an insulation fault signal, and outputs the latched insulation fault signal. When the BMS fault latching unit and / or the insulation fault latching unit outputs the latched fault signal, the charging protection circuit is immediately cut off, effectively reducing safety hazards caused by fuse or circuit breaker failure and significantly improving the real-time performance and reliability of charging protection.

Description

Technical Field

[0001] This application relates to the field of electric vehicle charging equipment technology, and in particular to a charging protection circuit, protection device, and portable charger for a portable charger. Background Technology

[0002] With the increasing popularity of electric vehicles, users have placed higher demands on the safety, reliability, and rapid response capabilities of charging equipment. During charging, portable charging devices need to connect to both the AC power source and the electric vehicle's Battery Management System (BMS). Due to the complex and variable charging environment, conditions such as grid voltage fluctuations, battery overcharging, and insulation abnormalities can occur. If the protection mechanism of the charging protection circuit in the portable charging device responds slowly or fails, it can easily lead to serious consequences such as equipment damage, electric shock risk, or even fire. Therefore, portable charging devices must have fault detection and rapid power-off capabilities to cope with various sudden fault conditions and ensure a safe and reliable charging process.

[0003] In related technologies, existing portable charging devices generally adopt a traditional single-point protection architecture based on fuses and circuit breakers. This type of charging protection circuit is typically divided into two parts: a main charging circuit and a charging control circuit. The input of the main charging circuit is connected to an AC power source via a power supply interface, while the output is connected to the electric vehicle to be charged via a charging interface. The circuit sequentially includes components such as a circuit breaker, charging module, fuse, and output contactors (e.g., K1, K2, K3, K4). The charging control circuit mainly includes a controller, auxiliary power supply, and output relays. During normal charging, the controller drives the contactors and communicates with the BMS to collaboratively manage the charging process. Once the system detects an anomaly, the controller immediately sends a shutdown command to the charging module and disconnects the contactors to cut off the output, while simultaneously controlling the fuse or circuit breaker to open. However, this approach presents safety hazards due to fuse or circuit breaker failure, making it difficult to meet the demands of current high-reliability charging scenarios. Summary of the Invention

[0004] The portable charger, including its charging protection circuit, protection device, and portable charger, provided in this application, aims to improve the safety hazards caused by fuse or circuit breaker failures in related technologies, which make it difficult to meet the needs of current high-reliability charging scenarios.

[0005] In a first aspect, this application provides a charging protection circuit for a portable charger, comprising: a voltage conversion unit, a battery management system (BMS) fault latching unit, and an insulation fault latching unit;

[0006] The voltage conversion unit includes an input terminal and an output terminal. The input terminal is used to receive external AC input voltage signals, and the voltage conversion unit is used to convert the external AC input voltage signals into low-voltage DC power signals and output them through the output terminal.

[0007] The BMS fault latching unit includes a first input terminal, a second input terminal, and a first output terminal. The first input terminal is connected to the output terminal, and the second input terminal is connected to the BMS. It is used to receive the BMS status signal sent by the BMS. The BMS fault latching unit is used to latch the BMS fault signal when the BMS status signal is a BMS fault signal, and output the latched BMS fault signal through the first output terminal.

[0008] The first input terminal of the insulation fault latching unit is connected to the first output terminal, and the second input terminal of the insulation fault latching unit is connected to the insulation detection board of the portable charger. It is used to acquire the insulation status signal detected by the insulation detection board. When the insulation status signal is an insulation fault signal, the insulation fault latching unit is used to latch the insulation fault signal and output the latched insulation fault signal through the output terminal of the insulation fault latching unit. The output terminal of the insulation fault latching unit is connected to the electric vehicle to be charged.

[0009] Specifically, when the BMS fault latching unit outputs a latched BMS fault signal and / or the insulation fault latching unit outputs a latched insulation fault signal, the charging protection circuit of the portable charger is immediately cut off to interrupt the charging of the electric vehicle to be charged.

[0010] In one possible implementation, the charging protection circuit of the portable charger further includes an emergency stop switch module connected in series in the charging protection circuit of the portable charger. The input terminal of the emergency stop switch module is connected to its output terminal, and its output terminal is connected to a first input terminal. The emergency stop switch module is used to immediately and forcibly disconnect the charging protection circuit of the portable charger when a target condition is met. The target condition includes any one of the following: the operator manually triggers the emergency stop operation; the BMS fault latch unit receives a BMS fault signal and the charging protection circuit of the portable charger is not disconnected within a first preset time period; the insulation fault latch unit receives an insulation fault signal and the charging protection circuit of the portable charger is not disconnected within a second preset time period.

[0011] In one possible implementation, the charging protection circuit of the portable charger further includes a discharge relay module. The control terminal of the discharge relay module is connected to the first output terminal and the output terminal of the insulation fault latching unit, respectively. The main circuit of the discharge relay module is connected between the output terminal of the charger and the discharge circuit. When the charging protection circuit of the portable charger is cut off due to a fault, the discharge relay module conducts the discharge resistor in the discharge circuit so that the residual electrical energy at the output terminal of the charger is released through the discharge resistor.

[0012] In one possible implementation, the discharge relay module is a normally closed power relay.

[0013] In one possible implementation, the charging protection circuit of the portable charger further includes a BMS fault signal display unit and an insulation fault signal display unit. The first terminal of the BMS fault signal display unit is connected to a first output terminal, and the second terminal of the BMS fault signal display unit is grounded. The BMS fault signal display unit is used to issue an indication signal indicating the presence of a BMS fault when the first output terminal outputs a latched BMS fault signal. Similarly, the first terminal of the insulation fault signal display unit is connected to the output terminal of the insulation fault latching unit, and the second terminal of the insulation fault signal display unit is grounded. The insulation fault signal display unit is used to issue an indication signal indicating the presence of an insulation fault when the output terminal of the insulation fault latching unit outputs a latched insulation fault signal.

[0014] In one possible implementation, the BMS fault signal display unit and the insulation fault signal display unit include signal indicator lights.

[0015] In one possible implementation, the BMS fault latch unit includes a signal conditioning circuit, a voltage comparator, and a reset-set latch. The input terminal of the signal conditioning circuit serves as the second input terminal, used to filter and level-convert the received BMS status signal to obtain a processed signal, which is then output through the output terminal of the signal conditioning circuit. The non-inverting input terminal of the voltage comparator is connected to the output terminal of the signal conditioning circuit, and the inverting input terminal of the voltage comparator is connected to a set voltage threshold. The voltage comparator compares the processed signal with the set voltage threshold to obtain a comparison result, which is then output through the output terminal of the voltage comparator. The set input terminal of the reset-set latch is connected to the output terminal of the voltage comparator, and the reset input terminal of the reset-set latch is connected to a global reset signal. The output terminal of the reset-set latch serves as the first output terminal. When the comparison result indicates that the BMS status signal is a BMS fault signal, the reset-set latch latches the comparison result as a latched insulation fault signal and outputs the latched insulation fault signal through the first output terminal until the reset input terminal receives the global reset signal.

[0016] In one possible implementation, the insulation fault latching unit includes a differential sampling circuit, an analog-to-digital converter (ADC), and a digital latch. The input of the differential sampling circuit serves as the second input of the insulation fault latching unit, used to acquire the insulation status signal output by the insulation detection board, and outputs a single-ended sampled signal through the output of the differential sampling circuit. The input of the ADC is connected to the output of the differential sampling circuit, and the ADC converts the sampled signal into a digital value, which is output through the output of the ADC. The input of the digital latch is connected to the output of the ADC, and the output of the digital latch serves as the output of the insulation fault latching unit. When the digital value represents an insulation fault signal, the digital latch latches the digital value as the latched insulation fault signal and outputs the latched insulation fault signal through the output of the insulation fault latching unit.

[0017] Secondly, this application provides a protection device, including a charging protection circuit for a portable charger as described in any of the first aspects.

[0018] Thirdly, this application provides a portable charger, including the protective device as described in the second aspect.

[0019] The portable charger provided in this application includes a charging protection circuit, a protection device, and a portable charger, comprising: a voltage conversion unit, a battery management system (BMS) fault latching unit, and an insulation fault latching unit; the voltage conversion unit includes an input terminal and an output terminal, the input terminal being used to receive an external AC input voltage signal, the voltage conversion unit being used to convert the external AC input voltage signal into a low-voltage DC power signal, and outputting it through the output terminal; the BMS fault latching unit includes a first input terminal, a second input terminal, and a first output terminal, the first input terminal being connected to the output terminal, the second input terminal being connected to the BMS, being used to receive a BMS status signal sent by the BMS, the BMS fault latching unit being used to latch the BMS fault signal when the BMS status signal is a BMS fault signal, and outputting the latched signal through the first output terminal. The processed BMS fault signal; the first input terminal of the insulation fault latching unit is connected to the first output terminal, and the second input terminal of the insulation fault latching unit is connected to the insulation detection board of the portable charger to acquire the insulation status signal detected by the insulation detection board. The insulation fault latching unit is used to latch the insulation fault signal when the insulation status signal is an insulation fault signal, and outputs the latched insulation fault signal through the output terminal of the insulation fault latching unit. The output terminal of the insulation fault latching unit is connected to the electric vehicle to be charged. When the BMS fault latching unit outputs the latched BMS fault signal and / or the insulation fault latching unit outputs the latched insulation fault signal, the charging protection circuit of the portable charger is immediately cut off to interrupt the charging of the electric vehicle to be charged.

[0020] This application introduces a voltage conversion unit, a BMS fault latching unit, and an insulation fault latching unit to form a charging protection circuit for a portable charger based on multiple fault detection and rapid response. This effectively reduces the safety hazards caused by the slow or failed operation of mechanical components such as fuses and circuit breakers in related technologies. Furthermore, this circuit can complete state latching the instant a BMS fault signal or insulation fault signal appears and immediately trigger the charging circuit cutoff mechanism, effectively eliminating the inherent time delay in controller communication, judgment, and execution, achieving millisecond-level fault isolation, and significantly improving the real-time performance and reliability of charging protection. Simultaneously, this design significantly reduces reliance on mechanical protection components, effectively expanding the protection capability against non-overcurrent faults such as battery overcharging, voltage anomalies, and insulation faults, overcoming traditional protection blind spots, and thus comprehensively enhancing the safety and operational reliability of portable chargers under complex operating conditions, better meeting the needs of current high-reliability charging scenarios. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] Figure 1 A schematic diagram of the charging protection circuit of a portable charger provided as an exemplary embodiment of this application. Figure 1 ;

[0023] Figure 2 A schematic diagram of the charging protection circuit of a portable charger provided as an exemplary embodiment of this application. Figure 2 ;

[0024] Figure 3 A schematic diagram of the charging protection circuit of a portable charger provided as an exemplary embodiment of this application. Figure 3 .

[0025] Figure label:

[0026] 10. Charging protection circuit for portable charger; 11. Voltage conversion unit; 12. BMS fault latching unit; 13. Insulation fault latching unit; 14. Electric vehicle waiting to be charged; 15. Emergency stop switch module.

[0027] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0028] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0029] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the connection within two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0031] In the above description, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0032] In order to enable those skilled in the art to better understand the technical solutions provided in the embodiments of this application, the solutions of related technologies will be introduced before introducing the technical solutions provided in the embodiments of this application.

[0033] In related technologies, existing portable charging devices generally adopt a traditional single-point protection architecture based on fuses and circuit breakers. Although this architecture achieves a certain fault detection capability through communication between the controller and the BMS, there is an unavoidable time difference between fault identification, controller decision-making and final power-off execution when an anomaly occurs, making instantaneous protection impossible. At the same time, fuses or circuit breakers can only respond to limited faults such as overcurrent and short circuits, and are completely ineffective against non-overcurrent risks such as battery overcharging, abnormal voltage and insulation faults. Moreover, once the fuse or circuit breaker itself fails due to aging, quality or mechanical jamming, the entire protection chain will fail, making it difficult to meet the stringent safety and real-time requirements of high-reliability charging scenarios.

[0034] To address the aforementioned issues, this application provides a charging protection circuit scheme for a portable charger. By introducing a voltage conversion unit, a BMS fault latch unit, and an insulation fault latch unit to form a series circuit, the BMS fault latch unit monitors BMS faults, and the insulation fault latch unit monitors insulation faults. This creates a charging protection circuit based on multiple fault detection and rapid response, effectively reducing the safety hazards caused by the slow or failed operation of mechanical components such as fuses and circuit breakers in related technologies. Furthermore, this circuit can complete state latching the moment a BMS fault signal or insulation fault signal appears and immediately trigger the charging circuit cutoff mechanism, effectively eliminating the inherent time delay in controller communication, judgment, and execution, achieving rapid fault isolation, and significantly improving the real-time performance and reliability of charging protection. Simultaneously, this design significantly reduces reliance on mechanical protection components, effectively expanding the protection capabilities against non-overcurrent faults such as battery overcharging, voltage anomalies, and insulation faults, overcoming traditional protection blind spots, and thus comprehensively enhancing the safety and operational reliability of portable chargers under complex operating conditions, better meeting the needs of current high-reliability charging scenarios.

[0035] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0036] Figure 1 A schematic diagram of the charging protection circuit of a portable charger provided as an exemplary embodiment of this application. Figure 1 .like Figure 1 As shown, the charging protection circuit 10 of the portable charger provided in this application embodiment includes: a voltage conversion unit 11, a BMS fault latching unit 12, and an insulation fault latching unit 13; wherein:

[0037] The voltage conversion unit 11 includes an input terminal and an output terminal. The input terminal is used to receive an external AC input voltage signal, and the voltage conversion unit 11 is used to convert the external AC input voltage signal into a low-voltage DC power signal and output it through the output terminal.

[0038] The BMS fault latching unit 12 includes a first input terminal, a second input terminal, and a first output terminal. The first input terminal is connected to the output terminal, and the second input terminal is connected to the BMS. It is used to receive the BMS status signal sent by the BMS. The BMS fault latching unit 12 is used to latch the BMS fault signal when the BMS status signal is a BMS fault signal, and output the latched BMS fault signal through the first output terminal.

[0039] The first input terminal of the insulation fault latching unit 13 is connected to the first output terminal, and the second input terminal of the insulation fault latching unit 13 is connected to the insulation detection board of the portable charger. It is used to acquire the insulation status signal detected by the insulation detection board. When the insulation status signal is an insulation fault signal, the insulation fault latching unit 13 is used to latch the insulation fault signal and output the latched insulation fault signal through the output terminal of the insulation fault latching unit 13. The output terminal of the insulation fault latching unit 13 is connected to the electric vehicle 14 to be charged.

[0040] Specifically, when the BMS fault latching unit 12 outputs a latched BMS fault signal and / or the insulation fault latching unit 13 outputs a latched insulation fault signal, the charging protection circuit of the portable charger is immediately cut off to interrupt the charging of the electric vehicle 14 to be charged.

[0041] For example, such as Figure 1 As shown, assuming the external AC input voltage signal is a 220V voltage signal, the voltage conversion unit 11 converts the high-voltage 220V voltage signal into a 12V low-voltage DC power signal. The 12V low-voltage DC power signal is output through the output terminal of the voltage conversion unit 11. The output terminal of the voltage conversion unit 11 is connected in series with the first input terminal of the BMS fault latch unit 12. At the same time, the output terminal of the voltage conversion unit 11 is connected to the power supply terminal of the BMS fault latch unit 12 and the power supply terminal of the insulation fault latch unit 13, which is used to provide working power for the BMS fault latch unit 12 and the insulation fault latch unit 13. The second input terminal of the BMS fault latch unit 12 is connected to the communication interface of the BMS, which is used to receive the BMS status signal sent by the BMS in real time. When the BMS fault latch unit 12 identifies the BMS status signal as a BMS fault signal (such as overvoltage, overtemperature, communication interruption, etc.), it immediately latches the BMS fault signal and outputs a stable and continuous high level (or low level) through its first output terminal as the latched BMS fault signal.

[0042] Correspondingly, the first input terminal of the insulation fault latching unit 13 is connected to the first output terminal of the BMS fault latching unit 12 to receive its output signal; the second input terminal of the insulation fault latching unit 13 is connected to the insulation detection board inside the portable charger to acquire the insulation status signal in real time; when the insulation resistance is detected to be lower than the preset safety threshold (i.e. the insulation status signal is a fault signal), the insulation fault latching unit 13 also latches the fault signal and outputs a stable latched insulation fault signal to the electric vehicle 14 to be charged through its output terminal.

[0043] Correspondingly, the output signals of the BMS fault latch unit 12 and the insulation fault latch unit 13 jointly control the on / off state of the charging main circuit through a logical OR relationship. Specifically, when the BMS fault latch unit 12 outputs a latched BMS fault signal, and / or the insulation fault latch unit 13 outputs a latched insulation fault signal, a high-speed disconnecting mechanism (such as a contactor or solid-state switch placed in the main circuit) is immediately driven to cut off the power output of the entire portable charger's charging protection circuit 10, thereby interrupting the charging process of the electric vehicle 14 to be charged. This parallel processing mechanism based on electronic latching achieves millisecond-level rapid response to multiple faults, greatly improving the safety of the charging process.

[0044] This application embodiment introduces a voltage conversion unit, a BMS fault latching unit, and an insulation fault latching unit to form a charging protection circuit based on multiple fault detection and fast response. This effectively reduces the safety hazards caused by the slow or failed operation of mechanical components such as fuses and circuit breakers in related technologies. Furthermore, this circuit can complete state latching the instant a BMS fault signal or insulation fault signal appears and immediately trigger the charging circuit cutoff mechanism, effectively eliminating the inherent time delay in controller communication, judgment, and execution, achieving millisecond-level fault isolation, and significantly improving the real-time performance and reliability of charging protection. Simultaneously, this design significantly reduces reliance on mechanical protection components, effectively expanding the protection capability against non-overcurrent faults such as battery overcharging, voltage anomalies, and insulation faults, overcoming traditional protection blind spots, and thus comprehensively enhancing the safety and operational reliability of portable chargers under complex operating conditions, better meeting the needs of current high-reliability charging scenarios.

[0045] In some embodiments, the charging protection circuit of the portable charger further includes an emergency stop switch module connected in series in the charging protection circuit of the portable charger. The input terminal of the emergency stop switch module is connected to its output terminal, and its output terminal is connected to a first input terminal. The emergency stop switch module is used to immediately and forcibly disconnect the charging protection circuit of the portable charger when a target condition is met. The target condition includes any one of the following: the operator manually triggers the emergency stop operation; the BMS fault latch unit receives a BMS fault signal and the charging protection circuit of the portable charger is not disconnected within a first preset time period; the insulation fault latch unit receives an insulation fault signal and the charging protection circuit of the portable charger is not disconnected within a second preset time period.

[0046] For example, Figure 2 A schematic diagram of the charging protection circuit of a portable charger provided as an exemplary embodiment of this application. Figure 2 .like Figure 2 As shown, the input terminal of the emergency stop switch module 15 is connected to the output terminal of the voltage conversion unit 11, and the output terminal of the emergency stop switch module 15 is connected to the first input terminal of the BMS fault latch unit 12. The emergency stop switch module 15 is configured to immediately and physically forcefully disconnect its internal circuit when any of the following target conditions are met, thereby cutting off the power supply to the subsequent BMS fault latch unit 12 and insulation fault latch unit 13:

[0047] (1) Manual emergency operation: When the operator discovers an abnormal situation on site, he or she can manually trigger the mechanical button on the emergency stop switch module 15 to perform an emergency power cut-off;

[0048] (2) BMS fault protection failure: When the BMS fault latch unit 12 receives a valid BMS fault signal at its second input terminal, if the main charging circuit is not properly disconnected within the first preset time (e.g., 100ms) (i.e., the main system protection fails), the timing and control circuit in the emergency stop switch module 15 will be automatically triggered to force power off as backup protection.

[0049] (3) Insulation fault protection failure: When the insulation fault latching unit 13 receives a valid insulation fault signal at its second input terminal, if the main charging circuit is not properly disconnected within the set second preset time (e.g., 100ms), the emergency stop switch module 15 will also be automatically triggered to force power off.

[0050] It should be noted that the above-mentioned first preset duration of 100ms and second preset duration of 100ms are just examples. In actual applications, they can be set according to actual application needs. The specific values ​​of the first preset duration and the second preset duration are not limited here.

[0051] In this embodiment, by introducing an emergency stop switch module, a triple protection mechanism combining manual emergency and automatic backup is provided. This not only empowers operators with the ability to intervene proactively and effectively solves the problem of slow response in manual emergency stops, but also, as an independent safety barrier, it can intervene and forcibly cut off the power supply of the entire system in a very short time when the BMS fault protection or insulation fault protection fails, thereby significantly improving the redundancy and reliability of the entire charging protection circuit.

[0052] In some embodiments, the charging protection circuit of the portable charger further includes a discharge relay module. The control terminal of the discharge relay module is connected to the first output terminal and the output terminal of the insulation fault latching unit, respectively. The main circuit of the discharge relay module is connected between the output terminal of the charger and the discharge circuit. When the charging protection circuit of the portable charger is cut off due to a fault, the discharge relay module conducts the discharge resistor in the discharge circuit so that the residual electrical energy at the output terminal of the charger is released through the discharge resistor.

[0053] For example, still refer to Figure 2 The control terminal of the discharge relay module is connected to the output terminals of the BMS fault latch unit and the insulation fault latch unit, respectively, to receive fault latch signals. The main circuit of the discharge relay module is connected between the charger output terminal and the discharge circuit. When the BMS fault latch unit 12 and / or the insulation fault latch unit 13 outputs a fault latch signal that causes the charging main circuit to be cut off, the fault latch signal will simultaneously trigger the discharge relay module to operate. The discharge relay module conducts the discharge resistor in the discharge circuit, so that the residual electrical energy stored at the charger output terminal and the DC bus filter capacitor will be quickly discharged to the discharge resistor through the newly conducted discharge circuit and converted into heat energy consumption.

[0054] In this embodiment, by introducing a discharge relay module, the discharge circuit can be automatically and immediately turned on after the charging protection circuit of the portable charger is cut off due to a fault. The residual high voltage energy at the charger output terminal and DC bus is quickly discharged through the discharge resistor and converted into heat energy consumption. This effectively eliminates the residual high voltage at the port after the power failure, significantly reduces the risk of electric shock in subsequent operations, and provides key protection for equipment maintenance and personnel safety. At the same time, it forms a complete safety protection closed loop from fault isolation to energy discharge, which significantly improves the overall safety and reliability of the system.

[0055] In some embodiments, the discharge relay module is a normally closed power relay.

[0056] Among them, a normally closed power relay refers to a power relay whose main contacts are in a closed conducting state when the relay coil is not energized, and the main contacts will only open when the coil is subjected to a rated voltage; a discharge relay module refers to a module composed of a relay coil, power contacts and a drive circuit, used to control the opening and closing of the discharge circuit; a discharge circuit is a path composed of a discharge resistor and connecting lines, used to convert electrical energy into heat energy for consumption.

[0057] For example, the discharge relay module uses a normally closed power relay (referred to as "relay"). The relay coil serves as its control terminal, receiving fault latching signals from the BMS fault latching unit and the insulation fault latching unit through a drive circuit. The function of this drive circuit includes: providing the rated operating voltage to the relay coil when there is no fault signal; and removing the voltage when a fault signal is present. The main circuit of the relay (i.e., its power contacts) is connected between the DC output terminal of the charger and the discharge resistor, forming a discharge circuit. When the system is charging normally and there are no faults, both the BMS fault latching unit and the insulation fault latching unit output invalid signals (such as low level). The drive circuit then provides the rated voltage to the relay coil accordingly. After the coil is energized, it generates magnetic force, which overcomes the spring force, causing the relay main contacts to change from the default normally closed state to the open state. At this time, the discharge circuit is cut off, ensuring that all electrical energy is used to charge the electric vehicle to be charged. Correspondingly, when any fault latch unit outputs a valid fault signal (such as a high level), the signal will cause the main charging circuit to be cut off. At the same time, the drive circuit will immediately remove the working voltage on the relay coil. Once the coil is de-energized, the magnetic force it generates disappears, and the main contacts of the relay will automatically return to their inherent normally closed state (i.e., closed state) under the action of the internal spring, immediately opening the discharge circuit. This allows the dangerous electrical energy remaining on the charger output terminal and the DC bus filter capacitor to be quickly discharged through the discharge resistor and consumed in the form of heat until the voltage drops to a safe range.

[0058] Based on the above embodiments, in some embodiments, the charging protection circuit of the portable charger further includes a BMS fault signal display unit and an insulation fault signal display unit. The first terminal of the BMS fault signal display unit is connected to the first output terminal, and the second terminal of the BMS fault signal display unit is grounded. The BMS fault signal display unit is used to issue an indication signal indicating the presence of a BMS fault when the first output terminal outputs a latched BMS fault signal. The first terminal of the insulation fault signal display unit is connected to the output terminal of the insulation fault latching unit, and the second terminal of the insulation fault signal display unit is grounded. The insulation fault signal display unit is used to issue an indication signal indicating the presence of an insulation fault when the output terminal of the insulation fault latching unit outputs a latched insulation fault signal.

[0059] For example, in some embodiments, the BMS fault signal display unit and the insulation fault signal display unit include signal indicator lights.

[0060] For example, when the BMS fault latch unit outputs a latched BMS fault signal, the indicator light in the BMS fault signal display unit connected to the output of the BMS fault latch unit will light up, emitting a clear light signal to indicate to the operator that a BMS fault exists. For example, the indicator light may be red or flashing rapidly to attract the operator's attention. Correspondingly, when the insulation fault latch unit outputs a latched insulation fault signal, the indicator light in the insulation fault signal display unit connected to the output of the insulation fault latch unit will light up, emitting a clear light signal to indicate to the operator that an insulation fault exists. For example, the indicator light may be red or flashing rapidly to attract the operator's attention.

[0061] In this embodiment of the application, by setting signal indicator lights in the BMS fault signal display unit and the insulation fault signal display unit, the operator only needs to observe the on / off state of the signal indicator lights to quickly understand whether a BMS fault or insulation fault has occurred during the charging process, which helps to take corresponding measures in a timely manner and effectively ensures charging safety.

[0062] In some embodiments, the BMS fault signal display unit and the insulation fault signal display unit include an audible alarm device.

[0063] For example, when a latched BMS fault signal is output from the output of the BMS fault latching unit, the audible alarm device in the BMS fault signal display unit connected to the output of the BMS fault latching unit will be triggered, emitting an audible alarm of a specific frequency or rhythm, such as a continuous beeping sound, to inform the operator of a BMS fault. Correspondingly, when an insulation fault signal is output from the output of the insulation fault latching unit, the audible alarm device in the insulation fault signal display unit connected to the output of the insulation fault latching unit will immediately respond, emitting a different audible signal, such as an intermittent alarm sound, to distinguish it from the audible prompts of a BMS fault, indicating the presence of an insulation fault.

[0064] In this embodiment of the application, by setting up audible alarm devices in the BMS fault signal display unit and the insulation fault signal display unit, the occurrence of faults can be detected in a timely manner by sound even when the operator does not directly observe the charger, which significantly improves the timeliness of fault detection and further enhances the safety of the charging process.

[0065] In some embodiments, the BMS fault latch unit includes a signal conditioning circuit, a voltage comparator, and a reset-set latch. The input terminal of the signal conditioning circuit serves as the second input terminal, used to filter and level-convert the received BMS status signal to obtain a processed signal, which is then output through the output terminal of the signal conditioning circuit. The non-inverting input terminal of the voltage comparator is connected to the output terminal of the signal conditioning circuit, and the inverting input terminal of the voltage comparator is connected to a set voltage threshold. The voltage comparator compares the processed signal with the set voltage threshold to obtain a comparison result, which is then output through the output terminal of the voltage comparator. The set input terminal of the reset-set latch is connected to the output terminal of the voltage comparator, and the reset input terminal of the reset-set latch is connected to a global reset signal. The output terminal of the reset-set latch serves as the first output terminal. When the comparison result indicates that the BMS status signal is a BMS fault signal, the reset-set latch latches the comparison result as a latched insulation fault signal and outputs the latched insulation fault signal through the first output terminal until the reset input terminal receives the global reset signal.

[0066] For example, the input terminal of the signal conditioning circuit serves as the second input terminal of the BMS fault latch unit, used to receive the raw status signal from the BMS. The signal conditioning circuit internally includes a low-pass filter network such as a resistor-capacitor (RC) filter and a level shifting circuit (such as a voltage divider network or a scaling circuit composed of operational amplifiers). Its function is to filter the raw signal to eliminate high-frequency noise interference and perform level shifting to adjust the input signal to the optimal input voltage range required by the subsequent voltage comparator, such as 0-3.3V. The processed signal is output through the output terminal of the signal conditioning circuit.

[0067] Accordingly, the voltage comparator is a high-speed voltage comparator chip such as the LM393. Its non-inverting input is connected to the output of the signal conditioning circuit to receive the processed signal, and its inverting input is connected to an adjustable resistor or the output of a digital-to-analog converter (DAC) to set a fixed voltage threshold, such as 2.5V. The comparator compares the processed signal with the set voltage threshold in real time. When the processed signal voltage is higher than the set voltage threshold, the comparator output (usually an open-collector output) will output a high level (indicating a fault); otherwise, it will output a low level (indicating normal operation). This comparison result is a preliminary digital fault judgment signal.

[0068] The reset-set latch can be a digital logic chip such as CD4043 or built from basic gate circuits; its set input is connected to the output of the voltage comparator, and its reset input is connected to the global reset signal provided by the system (usually from the main controller, which sends a pulse after power-on or fault clearing); its output is the output of the entire BMS fault latch unit, that is, the first output.

[0069] Correspondingly, when a BMS malfunctions, its status signal changes. After conditioning and comparison, if the voltage comparator outputs a high level (i.e., the comparison result indicates that the status signal is a BMS fault signal), this high-level signal acts on the set terminal of the reset-set latch, causing its output terminal to be set (flipped to and held at a high level), thereby outputting a stable and continuous "Latched BMS Fault Signal". Only when the system sends a valid pulse to the reset terminal of the reset-set latch through a global reset signal will the reset-set latch be cleared, and its output terminal will return to a low level, thereby releasing the fault indication and protection status.

[0070] In this embodiment, the close cooperation of the signal conditioning circuit, voltage comparator, and reset-set latch enables reliable detection, anti-interference judgment, and state maintenance of BMS fault signals, effectively ensuring the accuracy and stability of fault protection.

[0071] In some embodiments, the insulation fault latching unit includes a differential sampling circuit, an analog-to-digital converter (ADC), and a digital latch. The input of the differential sampling circuit serves as the second input of the insulation fault latching unit, used to acquire the insulation status signal output by the insulation detection board, and outputs a single-ended sampled signal through the output of the differential sampling circuit. The input of the ADC is connected to the output of the differential sampling circuit, and the ADC converts the sampled signal into a digital value, which is output through the output of the ADC. The input of the digital latch is connected to the output of the ADC, and the output of the digital latch serves as the output of the insulation fault latching unit. When the digital value represents an insulation fault signal, the digital latch latches the digital value as the latched insulation fault signal and outputs the latched insulation fault signal through the output of the insulation fault latching unit.

[0072] For example, the differential input terminal of the differential sampling circuit serves as the second input terminal of the insulation fault latching unit, directly connected to the signal output terminal of the insulation detection board inside the portable charger. The insulation detection board typically outputs a differential voltage signal inversely proportional to the insulation resistance value (e.g., the lower the insulation resistance, the more severe the fault, and the larger the output voltage difference). This differential sampling circuit is typically implemented by an instrumentation amplifier or differential operational amplifier circuit, and its core functions include: 1) suppressing common-mode noise: effectively eliminating the same interference superimposed on the two signal lines during transmission; 2) signal conversion: amplifying the differential voltage signal and converting it into a single-ended sampling signal referenced to ground for subsequent circuit processing. The processed single-ended sampling signal is output through the output terminal of the differential sampling circuit.

[0073] Accordingly, the analog-to-digital converter can employ high-precision analog-to-digital converter chips, such as SAR or Sigma-Delta type analog-to-digital converters (ADCs). The analog signal input terminal is connected to the output terminal of the differential sampling circuit to receive single-ended sampling signals. Under the control of the internal sampling clock, the ADC quantizes the continuous analog voltage signal into discrete digital values. These digital values ​​can be multi-bit wide (such as 12-bit or 16-bit) binary numbers, which are output through their digital output terminals (such as parallel or serial interfaces). These digital values ​​characterize the current insulation state of the system.

[0074] The digital latch can be implemented using a multi-bit wide D flip-flop such as the 74HC574 or through the internal logic resources of an FPGA / CPLD. Its data input is connected to the digital output of the ADC to receive the digital value converted by the ADC, and its clock control is connected to the ADC conversion completion signal or a specific sampling enable signal.

[0075] Correspondingly, the insulation detection board monitors the insulation status signal in real time. After differential sampling and ADC conversion, a corresponding digital value is obtained. When this value exceeds a preset safety threshold (i.e., the digital value represents an insulation fault signal), the digital latch latches this digital value as a latched insulation fault signal and outputs the latched insulation fault signal through the output terminal of the insulation fault latch unit. Afterwards, even if the insulation fault recovers momentarily, causing the ADC output value to return to normal, the output of the digital latch remains unchanged in the fault state, thus outputting a stable and continuous "latched insulation fault signal". In addition, the digital latch also includes a global reset terminal to receive a reset command from the system main controller, so as to clear the latched state after the fault is cleared.

[0076] This application embodiment effectively suppresses common-mode interference by utilizing a differential sampling circuit, ensuring the accuracy of signal acquisition. An analog-to-digital converter quantizes the analog signal into digital values, providing precise and flexibly settable digital data for fault diagnosis. A digital latch instantly captures and maintains the fault state; even if the fault disappears momentarily, the latched signal continues to output, ensuring the reliability and stability of the protection action. This technical approach, combining differential sampling, analog-to-digital conversion, and digital latching, significantly improves the anti-interference capability, accuracy, and reliability of state maintenance in insulation fault detection, thereby comprehensively enhancing the safety protection level of the portable charger's charging protection circuit.

[0077] For example, Figure 3 A schematic diagram of the charging protection circuit of a portable charger provided as an exemplary embodiment of this application. Figure 3 .like Figure 3 As shown, the charging protection circuit of this portable charger includes a voltage conversion unit, an emergency stop switch module, a BMS fault latch unit, a BMS fault signal indicator, an insulation fault latch unit, an insulation fault signal indicator, a discharge relay, a discharge resistor, and the charger itself. One input terminal of the BMS fault latch unit is used to receive the BMS status signal sent by the BMS, and one input terminal of the insulation fault latch unit is used to receive the insulation status signal detected by the insulation detection board of the portable charger. CAN-L (Controller Area Network Low) refers to a low-level signal line used to transmit low-voltage signals of the Controller Area Network (CAN) bus; CAN-H (Controller Area Network High) refers to a high-level signal line used to transmit high-voltage signals of the CAN bus; HV+ refers to the positive terminal of the high-voltage harness, and HV- refers to the negative terminal of the high-voltage harness.

[0078] Correspondingly, when the voltage conversion unit converts the 220V voltage signal into a 12V voltage signal, this 12V voltage signal serves as the main safety circuit, connecting the emergency stop switch module, BMS fault latch unit, insulation fault latch unit, and discharge relay in series. An additional 12V is provided as the power supply for the BMS fault latch unit and the insulation fault latch unit, as well as the power supply for wake-up when the vehicle is out of service. The electric vehicle can only be charged when the BMS fault latch unit and the insulation fault latch unit do not receive a fault signal. The main safety circuit is connected to the low-voltage power supply terminal of the power distribution unit (PDU) via a high-voltage interlock plug, forming a loop. During charging, if the BMS fault latch unit receives a BMS fault signal and / or the insulation fault latch unit receives an insulation fault signal, the main safety circuit is immediately disconnected, thereby disconnecting the high voltage and rapidly discharging, effectively protecting the charging circuit. The emergency stop switch module is used to quickly disconnect the charging circuit in case of abnormality during charging to ensure circuit safety. The voltage conversion unit, emergency stop switch module, BMS fault latch unit, insulation fault latch unit, and discharge relay all adopt a modular design to facilitate maintenance and upgrades, while also helping to achieve miniaturization and reduce design costs. The plug used to connect the charger and the electric vehicle to be charged is, for example, a high-voltage interlock plug, and the plug used to connect the electric vehicle to be charged and the charging protection circuit of the portable charger is, for example, an aviation plug.

[0079] This application also provides a protection device, including a charging protection circuit for a portable charger as described in any of the above embodiments.

[0080] By applying the charging protection circuit of the portable charger provided in the above embodiments to the protection device of this application embodiment, the device acquires electronic and fast-response multi-fault protection capabilities. This device not only quickly responds to and latches BMS faults and insulation faults, significantly reducing the action delay and single-point failure risk of traditional mechanical protection components, but also achieves end-to-end safety protection from fault detection and rapid power-off to safe discharge and status visualization by integrating functions such as discharge and status indication. This significantly improves the safety, reliability, and maintainability of the entire portable charging system, providing crucial protection for high-standard charging scenarios.

[0081] This application also provides a portable charger, including a charging protection circuit of the portable charger as described in any of the above embodiments, or the portable charger includes a protection device as described in the above embodiments.

[0082] By applying the charging protection circuit or protection device provided in the above embodiments to the portable charger of this application embodiment, the portable charger effectively solves the core pain points inherent in traditional solutions that rely on mechanical protection components, such as slow response, protection blind spots, and single-point failures. Moreover, the charger can monitor, quickly latch, and quickly cut off various abnormal states such as BMS faults and insulation faults in real time, and has the functions of safe discharge and status indication after faults. It realizes a complete electronic protection closed loop from fault perception to safe handling, which significantly improves the safety, reliability, and user experience of the portable charger in complex application environments, enabling it to meet the needs of various charging scenarios with extremely high safety standards.

[0083] In summary, this application has at least the following advantages:

[0084] I. By introducing a voltage conversion unit, a BMS fault latching unit, and an insulation fault latching unit, a charging protection circuit based on multiple fault detection and rapid response is formed. This effectively reduces the safety hazards caused by the slow action or failure of mechanical components such as fuses and circuit breakers in related technologies. Furthermore, this circuit can complete state latching the instant a BMS fault signal or insulation fault signal appears and immediately trigger the charging circuit cutoff mechanism, effectively eliminating the inherent time delay in controller communication, judgment, and execution, achieving millisecond-level fault isolation, and significantly improving the real-time performance and reliability of charging protection. Simultaneously, this design significantly reduces reliance on mechanical protection components, effectively expanding the protection capability against non-overcurrent faults such as battery overcharging, voltage anomalies, and insulation faults, overcoming traditional protection blind spots, and thus comprehensively enhancing the safety and operational reliability of portable chargers under complex operating conditions, better meeting the needs of current high-reliability charging scenarios.

[0085] Second, by introducing an emergency stop switch module, a triple protection mechanism combining manual emergency and automatic backup is provided. This not only empowers operators with the ability to intervene proactively and effectively solves the problem of slow response in manual emergency stops, but also, as an independent safety barrier, it can intervene and forcibly cut off the power supply of the entire system in a very short time when the BMS fault protection or insulation fault protection fails, thereby significantly improving the redundancy and reliability of the entire charging protection circuit.

[0086] Third, by introducing a discharge relay module, the discharge circuit can be automatically connected immediately after the charging protection circuit of the portable charger is cut off due to a fault. The residual high voltage energy at the charger output terminal and DC bus is quickly discharged through the discharge resistor and converted into heat energy consumption. This effectively eliminates the residual high voltage at the port after the power failure, significantly reduces the risk of electric shock in subsequent operations, and provides key protection for equipment maintenance and personnel safety. At the same time, it forms a complete safety protection closed loop from fault isolation to energy discharge, which significantly improves the overall safety and reliability of the system.

[0087] Finally, it should be noted that other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and alterations may be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A charging protection circuit for a portable charger, characterized in that, include: Voltage conversion unit, battery management system (BMS) fault latch unit, and insulation fault latch unit; The voltage conversion unit includes an input terminal and an output terminal. The input terminal is used to receive an external AC input voltage signal, and the voltage conversion unit is used to convert the external AC input voltage signal into a low-voltage DC power signal and output it through the output terminal. The BMS fault latching unit includes a first input terminal, a second input terminal, and a first output terminal. The first input terminal is connected to the output terminal, and the second input terminal is connected to the BMS. It is used to receive the BMS status signal sent by the BMS. The BMS fault latching unit is used to latch the BMS fault signal when the BMS status signal is a BMS fault signal, and output the latched BMS fault signal through the first output terminal. The first input terminal of the insulation fault latching unit is connected to the first output terminal, and the second input terminal of the insulation fault latching unit is connected to the insulation detection board of the portable charger. It is used to acquire the insulation status signal detected by the insulation detection board. When the insulation status signal is an insulation fault signal, the insulation fault latching unit is used to latch the insulation fault signal and output the latched insulation fault signal through the output terminal of the insulation fault latching unit. The output terminal of the insulation fault latching unit is connected to the electric vehicle to be charged. Specifically, when the BMS fault latching unit outputs the latched BMS fault signal, and / or the insulation fault latching unit outputs the latched insulation fault signal, the charging protection circuit of the portable charger is immediately cut off to interrupt the charging of the electric vehicle to be charged.

2. The charging protection circuit of the portable charger according to claim 1, characterized in that, It also includes an emergency stop switch module, which is connected in series in the charging protection circuit of the portable charger. The input terminal of the emergency stop switch module is connected to the output terminal, and the output terminal is connected to the first input terminal. The emergency stop switch module is used to immediately and forcibly disconnect the charging protection circuit of the portable charger when a target condition is met. The target condition includes any one of the following: The operator manually triggers the emergency stop procedure; After receiving the BMS fault signal, the BMS fault latching unit ensures that the charging protection circuit of the portable charger is not disconnected within a first preset time period. After receiving an insulation fault signal, the insulation fault latching unit ensures that the charging protection circuit of the portable charger is not disconnected within a second preset time period.

3. The charging protection circuit of the portable charger according to claim 1, characterized in that, It also includes a discharge relay module, the control terminal of which is connected to the first output terminal and the output terminal of the insulation fault latching unit, respectively. The main circuit of the discharge relay module is connected between the output terminal of the charger and the discharge circuit. When the charging protection circuit of the portable charger is cut off due to a fault, the discharge relay module conducts the discharge resistor in the discharge circuit so that the residual electrical energy at the output terminal of the charger is released through the discharge resistor.

4. The charging protection circuit of the portable charger according to claim 3, characterized in that, The discharge relay module is a normally closed power relay.

5. The charging protection circuit of the portable charger according to any one of claims 1 to 4, characterized in that, It also includes a BMS fault signal display unit and an insulation fault signal display unit, wherein: The first terminal of the BMS fault signal display unit is connected to the first output terminal, and the second terminal of the BMS fault signal display unit is grounded. The BMS fault signal display unit is used to issue an indication signal indicating the presence of a BMS fault when the latched BMS fault signal is output at the first output terminal. The first end of the insulation fault signal display unit is connected to the output end of the insulation fault latching unit, and the second end of the insulation fault signal display unit is grounded. The insulation fault signal display unit is used to issue an indication signal indicating the presence of an insulation fault when the latched insulation fault signal is output at the output end of the insulation fault latching unit.

6. The charging protection circuit of the portable charger according to claim 5, characterized in that, The BMS fault signal display unit and the insulation fault signal display unit include signal indicator lights.

7. The charging protection circuit of the portable charger according to any one of claims 1 to 4, characterized in that, The BMS fault latch unit includes a signal conditioning circuit, a voltage comparator, and a reset-set latch, wherein: The input terminal of the signal conditioning circuit serves as the second input terminal, used to filter and level-convert the received BMS status signal to obtain a processed signal, which is then output through the output terminal of the signal conditioning circuit. The non-inverting input of the voltage comparator is connected to the output of the signal conditioning circuit, and the inverting input of the voltage comparator is connected to a set voltage threshold. The voltage comparator is used to compare the processed signal with the set voltage threshold to obtain a comparison result, which is output through the output of the voltage comparator. The set input terminal of the reset-set latch is connected to the output terminal of the voltage comparator, the reset input terminal of the reset-set latch is connected to the global reset signal, and the output terminal of the reset-set latch serves as the first output terminal. When the comparison result indicates that the BMS status signal is a BMS fault signal, the reset-set latch latches the comparison result as the latched insulation fault signal and outputs the latched insulation fault signal through the first output terminal until the reset input terminal receives the global reset signal.

8. The charging protection circuit of the portable charger according to any one of claims 1 to 4, characterized in that, The insulation fault latching unit includes a differential sampling circuit, an analog-to-digital converter, and a digital latch, wherein: The input terminal of the differential sampling circuit serves as the second input terminal of the insulation fault latching unit, used to acquire the insulation status signal output by the insulation detection board, and outputs a single-ended sampling signal through the output terminal of the differential sampling circuit. The input terminal of the analog-to-digital converter is connected to the output terminal of the differential sampling circuit. The analog-to-digital converter is used to convert the sampled signal into a digital value, and the digital value is output through the output terminal of the analog-to-digital converter. The input terminal of the digital latch is connected to the output terminal of the analog-to-digital converter. The output terminal of the digital latch serves as the output terminal of the insulation fault latching unit. When the digital value representing the insulation state signal is an insulation fault signal, the digital latch latches the digital value as the latched insulation fault signal and outputs the latched insulation fault signal through the output terminal of the insulation fault latching unit.

9. A protective device, characterized in that, Includes the charging protection circuit of the portable charger as described in any one of claims 1 to 8.

10. A portable charger, characterized in that, Includes the protective device as described in claim 9.

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