Charging protection circuit and protection device of portable charger and portable charger

Abstract

The invention provides a charging protection circuit and protection device of a portable charger and the portable charger, and relates to the technical field of electric vehicle charging equipment. The circuit comprises a voltage conversion unit, a BMS fault latch unit and an insulation fault latch unit which are connected in series. The voltage conversion unit is used for outputting a low-voltage direct-current power signal; the BMS fault latching unit receives a BMS state signal, performs latching processing when the signal is a BMS fault signal, and outputs the BMS fault signal after latching processing; the insulation fault latching unit is used for acquiring an insulation state signal, latching the signal when the signal is an insulation fault signal, and outputting the latched insulation fault signal; when the BMS fault latch unit and / or the insulation fault latch unit output the latched fault signal, the charging protection circuit is cut off immediately, so that potential safety hazards caused by failure of a fuse or a circuit breaker are effectively reduced, and the real-time performance and reliability of charging protection are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicle charging equipment, and in particular to a charging protection circuit of a portable charger, a protection device and the portable charger. BACKGROUND

[0002] With the popularity of electric vehicles, users have higher requirements for the safety, reliability and rapid response capability of charging equipment. During the charging process, the portable charging equipment needs to be connected with the alternating current power supply and the battery management system (BMS) of the electric vehicle. Since the charging environment is complex and changeable, such as power grid voltage fluctuation, battery overcharging, insulation abnormality and other working conditions, if the protection mechanism of the charging protection circuit in the portable charging equipment responds slowly or fails, it is easy to cause equipment damage, electric shock risk and even fire and other serious consequences. Therefore, the portable charging equipment needs to have fault detection and ultra-fast power-off capability to cope with various sudden fault working conditions and ensure the safety and reliability of the charging process.

[0003] In related technologies, the existing portable charging equipment generally adopts a traditional single-point protection architecture based on fuses and circuit breakers. Such a charging protection circuit is usually divided into a charging main loop and a charging control loop. The input end of the charging main loop is connected to the alternating current power supply through the power supply interface, and the output end is connected to the electric vehicle to be charged through the charging interface. The circuit is arranged with circuit breakers, charging modules, fuses and output contactors (such as K1, K2, K3 and K4) and other components in sequence. The charging control loop mainly includes a controller, an auxiliary power supply and an output relay. In the normal charging process, the controller drives the contactors to act and communicates with the BMS to cooperatively manage the charging process. Once the system detects an abnormality, the controller immediately issues a shutdown instruction to the charging module and disconnects the contactors to cut off the output, while controlling the fuses or circuit breakers to disconnect. However, there is a safety hazard caused by the failure of the fuses or circuit breakers, which is difficult to meet the needs of current high-reliability charging scenarios. SUMMARY

[0004] The charging protection circuit of the portable charger, the protection device and the portable charger provided by the present application improve the safety hazard caused by the failure of the fuses or circuit breakers in related technologies, which is difficult to meet the needs of current high-reliability charging scenarios.

[0005] In a first aspect, the present application provides a charging protection circuit of 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 comprises an input end and an output end, the input end is used for receiving an external alternating current input voltage signal, and the voltage conversion unit is used for converting the external alternating current input voltage signal into a low-voltage direct current power supply signal and outputting the low-voltage direct current power supply signal through the output end.

[0007] The BMS fault latching unit comprises a first input end, a second input end and a first output end, the first input end is connected with the output end, the second input end is connected with the BMS and is used for receiving a BMS state signal sent by the BMS, and the BMS fault latching unit is used for performing latching processing on the BMS fault signal when the BMS state signal is the BMS fault signal and outputting the BMS fault signal after the latching processing through the first output end.

[0008] The first input end of the insulation fault latching unit is connected with the first output end, the second input end of the insulation fault latching unit is connected with the insulation detection plate of the portable charging machine, is used for acquiring an insulation state signal detected by the insulation detection plate, and the insulation fault latching unit is used for performing latching processing on the insulation fault signal when the insulation state signal is the insulation fault signal and outputting the insulation fault signal after the latching processing through the output end of the insulation fault latching unit, and the output end of the insulation fault latching unit is connected with the electric vehicle to be charged.

[0009] When the BMS fault latching unit outputs the BMS fault signal after the latching processing and / or the insulation fault latching unit outputs the insulation fault signal after the latching processing, the charging protection circuit of the portable charging machine is immediately cut off to interrupt the charging of the electric vehicle to be charged.

[0010] In a possible implementation, the charging protection circuit of the portable charging machine further comprises an emergency stop switch module, the emergency stop switch module is connected in series in the charging protection circuit of the portable charging machine, the input end of the emergency stop switch module is connected with the output end, the output end of the emergency stop switch module is connected with the first input end, and the emergency stop switch module is used for forcibly disconnecting the charging protection circuit of the portable charging machine immediately when a target condition is met, the target condition includes any one of the following: an operator manually triggers an emergency stop operation; the BMS fault latching unit receives the BMS fault signal, and the charging protection circuit of the portable charging machine is not cut off within a first preset time length after the BMS fault signal is received; the insulation fault latching unit receives the insulation fault signal, and the charging protection circuit of the portable charging machine is not cut off within a second preset time length after the insulation fault signal is received.

[0011] In a possible implementation, the charging protection circuit of the portable charger further comprises a discharge relay module, control ends of the discharge relay module are connected with the first output end and the output end of the insulation fault latch unit respectively, and a main circuit of the discharge relay module is connected between the output end of the charger and a discharge circuit; when the charging protection circuit of the portable charger is cut off due to a fault, the discharge relay module turns on a discharge resistor in the discharge circuit, so that residual energy at the output end of the charger is released through the discharge resistor.

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

[0013] In a possible implementation, the charging protection circuit of the portable charger further comprises a BMS fault signal display unit and an insulation fault signal display unit, a first end of the BMS fault signal display unit is connected with the first output end, a second end of the BMS fault signal display unit is grounded, the BMS fault signal display unit is configured to output an indication signal indicating that there is a BMS fault when the first output end outputs the latch-processed BMS fault signal, a first end of the insulation fault signal display unit is connected with the output end of the insulation fault latch unit, and a second end of the insulation fault signal display unit is grounded, the insulation fault signal display unit is configured to output an indication signal indicating that there is an insulation fault when the output end of the insulation fault latch unit outputs the latch-processed insulation fault signal.

[0014] In a possible implementation, the BMS fault signal display unit and the insulation fault signal display unit comprise signal indicator lamps.

[0015] In a possible implementation, the BMS fault latch unit comprises a signal conditioning circuit, a voltage comparator and a reset-set latch, an input end of the signal conditioning circuit is used as the second input end, configured to filter and perform level conversion on the received BMS state signal to obtain a processed signal, the processed signal is output through an output end of the signal conditioning circuit, a non-inverting input end of the voltage comparator is connected with the output end of the signal conditioning circuit, an inverting input end of the voltage comparator is connected with a set voltage threshold, the voltage comparator is configured to compare the processed signal with the set voltage threshold to obtain a comparison result, the comparison result is output through an output end of the voltage comparator, a set input end of the reset-set latch is connected with the output end of the voltage comparator, a reset input end of the reset-set latch is connected with a global reset signal, and an output end of the reset-set latch is used as the first output end; when the comparison result represents the BMS state signal as the BMS fault signal, the reset-set latch latches the comparison result as the latch-processed insulation fault signal and outputs the latch-processed insulation fault signal through the first output end until the reset input end receives the global reset signal.

[0016] In a possible implementation, the insulation fault latching unit comprises a differential sampling circuit, an analog-to-digital converter, and a digital latch, wherein the input end of the differential sampling circuit serves as the second input end of the insulation fault latching unit, is used to collect the insulation state signal output by the insulation detection board, and outputs a single-ended sampling signal through the output end of the differential sampling circuit; the input end of the analog-to-digital converter is connected to the output end of the differential sampling circuit, and the analog-to-digital converter is used to convert the sampling signal into a digital value, which is output through the output end of the analog-to-digital converter; the input end of the digital latch is connected to the output end of the analog-to-digital converter, and the output end of the digital latch serves as the output end of the insulation fault latching unit; when the digital value represents that the insulation state signal is an insulation fault signal, the digital latch latches the digital value as a latched insulation fault signal, and outputs the latched insulation fault signal through the output end of the insulation fault latching unit.

[0017] In a second aspect, the application provides a protection device, comprising the charging protection circuit of the portable charger according to any one of the first aspect.

[0018] In a third aspect, the application provides a portable charger, comprising the protection device according to the second aspect.

[0019] The charging protection circuit of the portable charger, the protection device, and the portable charger provided by the application comprise: a voltage conversion unit, a battery management system (BMS) fault latching unit, and an insulation fault latching unit; the voltage conversion unit comprises an input end and an output end, the input end is used to receive an external alternating current input voltage signal, and the voltage conversion unit is used to convert the external alternating current input voltage signal into a low-voltage direct current power supply signal and output the low-voltage direct current power supply signal through the output end; the BMS fault latching unit comprises a first input end, a second input end, and a first output end, the first input end is connected to the output end, the second input end is connected to the BMS, is used to receive a BMS state signal sent by the BMS, and the BMS fault latching unit is used to latch the BMS state signal when the BMS state signal is a BMS fault signal, and output the latched BMS fault signal through the first output end; the first input end of the insulation fault latching unit is connected to the first output end, the second input end of the insulation fault latching unit is connected to an insulation detection board of the portable charger, is used to obtain an insulation state signal detected by the insulation detection board, and the insulation fault latching unit is used to latch the insulation state signal when the insulation state signal is an insulation fault signal, and output the latched insulation fault signal through the output end of the insulation fault latching unit; the output end of the insulation fault latching unit is connected to an 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] The application forms a charging protection circuit of a portable charger based on multiple fault detection and rapid response by introducing a voltage conversion unit, a BMS fault latching unit and an insulation fault latching unit, effectively reducing the safety hazards caused by the slow action or failure of mechanical elements such as fuses and circuit breakers in the related art; and the circuit can complete state latching at the moment when the BMS fault signal or the insulation fault signal appears, and immediately trigger the charging loop shutdown mechanism, effectively eliminating the inherent time delay of the controller communication, judgment and execution link, realizing millisecond-level fault isolation, and significantly improving the real-time performance and reliability of the charging protection. At the same time, the design significantly reduces the dependence on mechanical protection elements, effectively expands the protection capability for non-overcurrent faults such as battery overcharging, voltage abnormalities and insulation faults, overcomes the traditional protection blind area, and thus comprehensively enhances the safety and operation reliability of the portable charger under complex working conditions, and better meets the current demand for high-reliability charging scenarios. BRIEF DESCRIPTION OF DRAWINGS

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

[0022] Figure 1 Structure diagram of the charging protection circuit of the portable charger provided for the exemplary embodiments of the present application Figure One ;

[0023] Figure 2 Structure diagram of the charging protection circuit of the portable charger provided for the exemplary embodiments of the present application Figure Two ;

[0024] Figure 3 Structure diagram of the charging protection circuit of the portable charger provided for the exemplary embodiments of the present application Figure Three .

[0025] Reference signs:

[0026] 10, charging protection circuit of a portable charger; 11, voltage conversion unit; 12, BMS fault latching unit; 13, insulation fault latching unit; 14, electric vehicle to be charged; 15, emergency stop switch module.

[0027] Through the above drawings, the specific embodiments of the present application have been shown, and will be described in more detail hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0028] It should be noted that the terms "first", "second" are used only for descriptive purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise explicitly specified.

[0029] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, it can be the connection or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0030] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0031] In the above description, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification and the features of different embodiments or examples without contradiction.

[0032] In order for those skilled in the art to more clearly understand the technical solutions provided by the embodiments of the present application, before introducing the technical solutions provided by the embodiments of the present application, the solutions of related art are introduced.

[0033] In the related art, the existing portable charging device generally adopts a traditional single-point protection architecture based on a fuse and a circuit breaker. The architecture realizes certain fault detection capability through communication between a controller and a BMS. However, when an abnormality occurs, there is an inevitable time difference between fault identification, controller decision, and final execution of power-off, and instantaneous protection cannot be realized. Meanwhile, the fuse or the circuit breaker can only respond to limited faults such as overcurrent and short circuit, and is completely ineffective for non-overcurrent risks such as overcharging, voltage abnormality, and insulation fault. Moreover, once the fuse or the circuit breaker fails due to aging, quality, or mechanical jamming, the entire protection chain will fail, and it is difficult to meet the strict requirements of high-reliability charging scenarios on safety and real-time performance.

[0034] To solve the above problems, the present application provides a charging protection circuit scheme of a portable charger. A voltage conversion unit, a BMS fault latching unit, and an insulation fault latching unit are introduced to form a series loop. The BMS fault latching unit is used to monitor BMS faults, and the insulation fault latching unit is used to monitor insulation faults, forming a charging protection circuit based on multiple fault detection and rapid response. This effectively reduces the safety hazards caused by the slow action or failure of mechanical elements such as fuses and circuit breakers in the related art. The circuit can complete state latching at the moment when a BMS fault signal or an insulation fault signal appears, and immediately trigger the charging loop shutdown mechanism, effectively eliminating the inherent time delay in the controller communication, judgment, and execution link, realizing rapid fault isolation, and significantly improving the real-time performance and reliability of the charging protection. At the same time, this design significantly reduces the dependence on mechanical protection elements, effectively expands the protection capability for non-overcurrent faults such as overcharging, voltage abnormality, and insulation fault, overcomes the traditional protection blind area, and thus comprehensively enhances the safety and operation reliability of the portable charger under complex working conditions, better meeting the needs of current high-reliability charging scenarios.

[0035] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following 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 the present application will be described below with reference to the accompanying drawings.

[0036] Figure 1 Structure diagram of the charging protection circuit of the portable charger provided for the exemplary embodiments of the present application Figure One As shown in Figure 1 , the charging protection circuit 10 of the portable charger provided by the embodiments of the present application 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 comprises an input end and an output end, the input end is used for receiving an external alternating input voltage signal, and the voltage conversion unit 11 is used for converting the external alternating input voltage signal into a low-voltage direct-current power supply signal and outputting the low-voltage direct-current power supply signal through the output end;

[0038] The BMS fault latching unit 12 comprises a first input end, a second input end and a first output end, the first input end is connected with the output end, the second input end is connected with the BMS, and is used for receiving a BMS state signal sent by the BMS, the BMS fault latching unit 12 is used for performing latching processing on the BMS fault signal when the BMS state signal is the BMS fault signal, and outputting the BMS fault signal after the latching processing through the first output end;

[0039] The first input end of the insulation fault latching unit 13 is connected with the first output end, the second input end of the insulation fault latching unit 13 is connected with the insulation detection plate of the portable charging machine, and is used for obtaining an insulation state signal detected by the insulation detection plate, the insulation fault latching unit 13 is used for performing latching processing on the insulation fault signal when the insulation state signal is the insulation fault signal, and outputting the insulation fault signal after the latching processing through the output end of the insulation fault latching unit 13, and the output end of the insulation fault latching unit 13 is connected with the electric vehicle 14 to be charged;

[0040] When the BMS fault latching unit 12 outputs the BMS fault signal after the latching processing and / or the insulation fault latching unit 13 outputs the insulation fault signal after the latching processing, the charging protection circuit of the portable charging machine is immediately cut off to interrupt the charging of the electric vehicle 14 to be charged.

[0041] For example, as shown in the figure, Figure 1 it is assumed that the external alternating input voltage signal is a 220V voltage signal, the high-voltage 220V voltage signal is converted into a 12V low-voltage direct-current power supply signal through the voltage conversion unit 11, the 12V low-voltage direct-current power supply signal is output through the output end of the voltage conversion unit 11, the output end of the voltage conversion unit 11 is connected in series with the first input end of the BMS fault latching unit 12, and the output end of the voltage conversion unit 11 is connected with the power supply end of the BMS fault latching unit 12 and the power supply end of the insulation fault latching unit 13, and is used for providing working power supply for the BMS fault latching unit 12 and the insulation fault latching unit 13; the second input end of the BMS fault latching unit 12 is connected with the communication interface of the BMS, and is used for receiving the BMS state signal sent by the BMS in real time, when the BMS fault latching unit 12 identifies that the BMS state signal is a BMS fault signal (such as overvoltage, overtemperature, communication interruption and the like), the BMS fault signal is immediately subjected to latching processing, and a stable and continuous high level (or low level) is output through the first output end as the BMS fault signal after the latching processing.

[0042] Correspondingly, the first input end of the insulation fault latch unit 13 is connected with the first output end of the BMS fault latch unit 12 to receive the output signal thereof; the second input end of the insulation fault latch unit 13 is connected to an insulation detection plate inside the portable charger to obtain an insulation state signal in real time; when it is detected that the insulation resistance is lower than a preset safety threshold (i.e. the insulation state signal is a fault signal), the insulation fault latch unit 13 also latches the fault signal and outputs a stable latched insulation fault signal to the electric vehicle 14 to be charged through the output end thereof.

[0043] Correspondingly, the output signals of the BMS fault latch unit 12 and the insulation fault latch unit 13 jointly control the on-off of the charging main circuit through a logic 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 breaking mechanism (such as a contactor or a solid-state switch placed in the main circuit) is immediately driven to cut off the power output of the charging protection circuit 10 of the portable charger, thereby interrupting the charging process of the electric vehicle 14 to be charged. This parallel processing mechanism based on electronic latching realizes millisecond-level fast response to multiple faults, greatly improving the safety of the charging process.

[0044] In the embodiment, by introducing the voltage conversion unit, the BMS fault latch unit and the insulation fault latch unit, a charging protection circuit based on multiple fault detection and fast response is formed, which effectively reduces the safety hazards caused by the slow action or failure of mechanical elements such as fuses and circuit breakers in the related art; and the circuit can complete state latching at the moment when the BMS fault signal or the insulation fault signal appears, and immediately trigger the charging circuit breaking mechanism, effectively eliminating the inherent time delay of the controller communication, judgment and execution link, realizing millisecond-level fault isolation, and significantly improving the real-time performance and reliability of the charging protection. At the same time, the design significantly reduces the dependence on mechanical protection elements, effectively expands the protection capability for non-overcurrent faults such as battery overcharging, voltage abnormality and insulation fault, overcomes the traditional protection blind area, and thus comprehensively enhances the safety and operation reliability of the portable charger under complex working conditions, better meeting the current demand for high-reliability charging scenarios.

[0045] In some embodiments, the charging protection circuit of the portable charger further comprises an emergency stop switch module connected in series in the charging protection circuit of the portable charger, wherein an input end of the emergency stop switch module is connected with an output end of the emergency stop switch module, and an output end of the emergency stop switch module is connected with the first input end, and the emergency stop switch module is configured to forcibly disconnect the charging protection circuit of the portable charger immediately when a target condition is met, and the target condition comprises any one of the following: an operator manually triggers an emergency stop operation; the BMS fault latching 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 latching 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 The structure of the charging protection circuit of the portable charger provided for the exemplary embodiments of the present application Figure Two As Figure 2 shown, the input end of the emergency stop switch module 15 is connected with the output end of the voltage conversion unit 11, and the output end of the emergency stop switch module 15 is connected with the first input end of the BMS fault latching unit 12; the emergency stop switch module 15 is configured to forcibly disconnect the internal circuit physically immediately when any one of the following target conditions is met, thereby cutting off the power supply to the BMS fault latching unit 12 and the insulation fault latching unit 13 in the rear stage:

[0047] (1) Manual emergency operation: when an operator finds an abnormal situation on site, manually triggers the mechanical button on the emergency stop switch module 15 to perform emergency power-off;

[0048] (2) BMS fault protection failure: when the BMS fault latching unit 12 receives a valid BMS fault signal at the second input end, if the charging main circuit is not normally disconnected (i.e., the system main protection fails) within a set first preset time period (e.g., 100 ms), the timing and control circuit in the emergency stop switch module 15 will automatically trigger as a backup protection to forcibly disconnect the power;

[0049] (3) Insulation fault protection failure: when the insulation fault latching unit 13 receives a valid insulation fault signal at the second input end, if the charging main circuit is not normally disconnected within a set second preset time period (e.g., 100 ms), the emergency stop switch module 15 will also automatically trigger to forcibly disconnect the power.

[0050] It should be noted that the first preset time period is, for example, 100 ms, and the second preset time period is, for example, 100 ms, which is only an example, and in actual application, the first preset time period and the second preset time period can be set according to actual application requirements, and the specific values of the first preset time period and the second preset time period are not limited herein.

[0051] The triple protection mechanism combining manual emergency and automatic backup is provided by introducing the emergency stop switch module, which not only gives the operator the ability to intervene actively and effectively solves the problem of slow reaction of manual emergency stop, but also as an independent safety barrier, when the BMS fault protection fails or the insulation fault protection fails, can intervene and forcibly cut off the working power supply of the entire system in a very short time, 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 comprises a discharge relay module, the control end of the discharge relay module is connected with the first output end and the output end of the insulation fault latching unit respectively, and the main circuit of the discharge relay module is connected between the charger output end and the discharge circuit; when the charging protection circuit of the portable charger is cut off due to failure, the discharge relay module turns on the discharge resistor in the discharge circuit to release the residual energy of the charger output end through the discharge resistor.

[0053] For example, still referring to Figure 2 , the control end of the discharge relay module is connected with the output end of the BMS fault latching unit and the output end of the insulation fault latching unit respectively, for receiving the fault latching signal; the main circuit of the discharge relay module is connected between the charger output end and the discharge circuit; after the BMS fault latching unit 12 and / or the insulation fault latching unit 13 output the fault latching signal to cut off the charging main circuit, the fault latching signal will trigger the discharge relay module to act at the same time, the discharge relay module turns on the discharge resistor in the discharge circuit, so that the residual energy stored on the charger output end and the DC bus filter capacitor will be quickly discharged to the discharge resistor through the newly turned on discharge circuit, and converted into heat energy consumption.

[0054] In the embodiments of the present application, by introducing the discharge relay module, after the charging protection circuit of the portable charger is cut off due to failure, the discharge circuit can be automatically turned on immediately, the high-voltage energy remaining on the charger output end and the DC bus is quickly discharged through the discharge resistor and converted into heat energy consumption, which effectively eliminates the residual high voltage of the port after failure, significantly reduces the risk of electric shock in subsequent operation, provides a key guarantee for equipment maintenance and personnel safety, and forms a complete safety protection closed loop from fault isolation to energy discharge, significantly improving the overall safety and reliability of the system.

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

[0056] The normally closed power relay refers to a power relay whose main contact is in a closed and conductive state when the relay coil is not powered, and the main contact is only disconnected when the coil is applied with a rated voltage. The discharge relay module refers to a module composed of a relay coil, power contacts and a driving circuit, used to control the on-off of a discharge circuit. The discharge circuit is a path composed of a discharge resistor and a connection circuit, used to convert electrical energy into heat energy for consumption.

[0057] By way of example, the discharge relay module is implemented by using a normally closed power relay (referred to as "relay" for short). The coil of the relay serves as its control terminal, and receives fault latching signals from the BMS fault latching unit and the insulation fault latching unit through a driving circuit. The driving circuit functions include: providing a rated working voltage for the relay coil when there is no fault signal; removing the voltage when there is a fault signal. The main circuit of the relay (i.e. its power contacts) is connected between the DC output of the charger and the discharge resistor, together forming a discharge circuit. When the system is normally charging and there is no any fault, the BMS fault latching unit and the insulation fault latching unit both output invalid signals (such as low level). The driving circuit provides a rated voltage for the relay coil accordingly. After the coil is powered, a magnetic force is generated to overcome the spring force, causing the main contact of the relay to switch 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 latching unit outputs a valid fault signal (such as high level), the signal will cause the main charging circuit to be cut off, and at the same time, the driving circuit will immediately remove the working voltage on the relay coil. Once the coil loses power, the magnetic force generated by the coil disappears, and the main contact of the relay automatically returns to its inherent normally closed state (i.e. closed state) under the action of the internal spring, immediately conducting the discharge circuit. The residual dangerous electrical energy on the output end of the charger and the DC bus filter capacitor is rapidly discharged through the discharge resistor and consumed in the form of heat energy until the voltage drops to a safe range.

[0058] On the basis of the above embodiment, 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 end of the BMS fault signal display unit is connected to the first output end, and the second end of the BMS fault signal display unit is grounded. The BMS fault signal display unit is used to issue an indication signal indicating the existence of a BMS fault when the first output end outputs the BMS fault signal after latching processing. 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 existence of an insulation fault when the output end of the insulation fault latching unit outputs the insulation fault signal after latching processing.

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

[0060] For example, when the BMS fault latch unit outputs the latched BMS fault signal, the signal indicator light in the BMS fault signal display unit connected to the output end of the BMS fault latch unit is lit, emitting a clear light signal to indicate to the operator that there is a BMS fault, for example, the signal indicator light is lit red or presented in a fast flashing state, etc., to attract the attention of the operator. Correspondingly, when the insulation fault latch unit outputs the latched insulation fault signal, the signal indicator light in the insulation fault signal display unit connected to the output end of the insulation fault latch unit is lit, emitting a clear light signal to indicate to the operator that there is an insulation fault, for example, the signal indicator light is lit red or presented in a fast flashing state, etc., to attract the attention of the operator.

[0061] In the embodiments of the present application, by providing 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 light to quickly understand whether a BMS fault or an insulation fault occurs during the charging process, which helps to take appropriate measures in time and effectively ensures the charging safety.

[0062] In some embodiments, the BMS fault signal display unit and the insulation fault signal display unit comprise sound alarm devices.

[0063] For example, when the BMS fault latch unit outputs the latched BMS fault signal, the sound alarm device in the BMS fault signal display unit connected to the output end of the BMS fault latch unit is triggered, emitting a sound alarm of a specific frequency or rhythm, such as a continuous beep, to inform the operator that there is a BMS fault. Correspondingly, when the insulation fault latch unit outputs the latched insulation fault signal, the sound alarm device in the insulation fault signal display unit connected to the output end of the insulation fault latch unit responds immediately, emitting a different sound signal, for example, an intermittent alarm sound, to distinguish from the sound prompt of the BMS fault, for indicating that there is an insulation fault.

[0064] In the embodiments of the present application, by providing sound alarm devices in the BMS fault signal display unit and the insulation fault signal display unit, even if the operator does not directly observe the charger, the occurrence of the fault can also be perceived in time through the sound, significantly improving the timeliness of fault discovery and further enhancing the safety of the charging process.

[0065] In some embodiments, the BMS fault latching unit comprises a signal conditioning circuit, a voltage comparator, and a reset-set latch, wherein the input end of the signal conditioning circuit serves as the second input end, for filtering and level conversion on the received BMS state signal to obtain a processed signal, and the processed signal is output through the output end of the signal conditioning circuit; the non-inverting input end of the voltage comparator is connected to the output end of the signal conditioning circuit, and the inverting input end 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, and the comparison result is output through the output end of the voltage comparator; the set input end of the reset-set latch is connected to the output end of the voltage comparator, the reset input end of the reset-set latch is connected to a global reset signal, and the output end of the reset-set latch serves as the first output end; when the comparison result represents that the BMS state signal is a BMS fault signal, the reset-set latch latches the comparison result as a latched processed insulation fault signal, and outputs the latched processed insulation fault signal through the first output end until the reset input end receives the global reset signal.

[0066] For example, the input end of the signal conditioning circuit serves as the second input end of the BMS fault latching unit, for receiving an original state signal from the BMS; the signal conditioning circuit internally comprises a low-pass filter network such as a resistor-capacitor (RC) filter and a level conversion circuit (such as a resistor divider network or a scaling circuit composed of an operational amplifier), which functions to filter the original signal to eliminate high-frequency noise interference, and to perform level conversion to adjust the input signal to the optimal input voltage range required by the subsequent voltage comparator, for example, 0-3.3V; the processed signal is output through the output end of the signal conditioning circuit.

[0067] Correspondingly, the voltage comparator is a high-speed voltage comparator chip, for example, LM393, the non-inverting input end of which is connected to the output end of the signal conditioning circuit for receiving the processed signal, and the inverting input end of which is connected to an adjustable resistor or the output of a digital-to-analog converter (DAC) to set a fixed voltage threshold, for example, 2.5V. The comparator compares the processed signal with the set voltage threshold in real time; when the voltage of the processed signal is higher than the set voltage threshold, the output end (usually an open collector output) of the comparator outputs a high level (representing a fault); otherwise, it outputs a low level (representing normal), and the comparison result is a preliminary digital fault judgment signal.

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

[0069] Correspondingly, when the BMS is faulty, the state signal thereof changes, after conditioning and comparison, if the voltage comparator outputs a high level (that is, the comparison result represents that the state signal is a BMS fault signal), the high level signal acts on the set end of the reset-set latch, causing the output end thereof to be set (flipped to and kept high level), thereby outputting a stable and continuous "latch-processed BMS fault signal"; only when the system sends an effective pulse to the reset end of the reset-set latch through the global reset signal, the reset-set latch is cleared, the output end thereof returns to low level, thereby releasing the fault indication and protection state.

[0070] In the embodiments of the present application, through the close cooperation of the signal conditioning circuit, the voltage comparator and the reset-set latch, reliable detection, anti-interference judgment and state keeping of the BMS fault signal are realized, thereby effectively ensuring the accuracy and stability of the fault protection.

[0071] In some embodiments, the insulation fault latch unit comprises a differential sampling circuit, an analog-digital converter and a digital latch, wherein the input end of the differential sampling circuit serves as the second input end of the insulation fault latch unit, is used for collecting the insulation state signal output by the insulation detection board, and outputs a single-ended sampling signal through the output end of the differential sampling circuit; the input end of the analog-digital converter is connected with the output end of the differential sampling circuit, the analog-digital converter is used for converting the sampling signal into a digital value, the digital value is output through the output end of the analog-digital converter; the input end of the digital latch is connected with the output end of the analog-digital converter, the output end of the digital latch serves as the output end of the insulation fault latch unit, when the digital value represents that the insulation state signal is an insulation fault signal, the digital latch latches the digital value as a latch-processed insulation fault signal, and outputs the latch-processed insulation fault signal through the output end of the insulation fault latch unit.

[0072] For example, the differential input of the differential sampling circuit is directly connected to the signal output of the internal insulation detection board of the portable charger as the second input of the insulation fault latch unit. The insulation detection board usually outputs a differential voltage signal inversely proportional to the insulation resistance value (for example, the lower the insulation resistance, the more serious the fault, and the larger the output voltage difference). The differential sampling circuit is usually implemented by an instrument amplifier or a differential operational amplifier circuit, and its core functions include: 1) common-mode noise suppression: effectively eliminating the same interference superimposed on the two signal lines during transmission; 2) signal conversion: amplifying and converting the differential voltage signal into a single-ended sampling signal with ground as a reference for subsequent circuit processing. The processed single-ended sampling signal is output through the output of the differential sampling circuit.

[0073] Correspondingly, the analog-to-digital converter can use a high-precision analog-to-digital converter chip such as a SAR-type or Sigma-Delta-type analog-to-digital converter (ADC). The analog signal input of the ADC is connected to the output of the differential sampling circuit to receive the single-ended sampling signal. Under the control of the internal sampling clock, the ADC quantizes the continuous analog voltage signal into a discrete digital value, which can be a multi-bit (such as 12-bit or 16-bit) binary number. The digital value is output through the digital output (such as a parallel or serial interface). This digital value represents the current insulation state of the system.

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

[0075] Correspondingly, the insulation detection board monitors the insulation state signal in real time, and after differential sampling and ADC conversion, the corresponding digital value is obtained. When the value exceeds the preset safety threshold (i.e., the digital value represents an insulation fault signal), the digital latch latches the digital value as a latched insulation fault signal and outputs the latched insulation fault signal through the output of the insulation fault latch unit. After that, even if the insulation fault is restored temporarily, the output of the digital latch remains in the fault state, thereby outputting a stable and continuous "latched insulation fault signal". In addition, the digital latch also includes a global reset end for receiving a reset command from the system main controller to clear the latch state after troubleshooting.

[0076] The application embodiment effectively suppresses common-mode interference by using a differential sampling circuit, effectively ensures the accuracy of signal acquisition; uses an analog-to-digital converter to quantize an analog signal to a digital value, provides an accurate, flexible threshold setting digital basis for fault judgment; uses a digital latch to instantaneously capture and hold the fault state, even if the fault disappears instantaneously, the latch signal still continues to output, ensuring the reliability and stability of the protection action. Through this technical path combining differential sampling, analog-to-digital conversion and digital latching, the anti-interference ability, judgment accuracy and state holding reliability of the insulation fault detection are significantly improved, thereby comprehensively enhancing the safety protection level of the charging protection circuit of the portable charger.

[0077] Exemplarily, Figure 3 The structure of the charging protection circuit of the portable charger provided by the exemplary embodiment of the application is shown in Figure Three . As Figure 3 shown, the charging protection circuit of the 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 a charger; an input end of the BMS fault latch unit is used to receive a BMS state signal sent by the BMS, and an input end of the insulation fault latch unit is used to receive an insulation state signal detected by an insulation detection board of the portable charger; CAN-L (Controller Area Network Low) refers to a low-level signal line, which is used to transmit a low-voltage signal of a Controller Area Network (CAN) bus; CAN-H (Controller Area Network High) refers to a high-level signal line, which is used to transmit a high-voltage signal of the CAN bus; HV+ refers to a high-voltage wire harness positive electrode, and HV- refers to a high-voltage wire harness negative electrode.

[0078] Correspondingly, when the voltage conversion unit converts the 220V voltage signal into a 12V voltage signal, the 12V voltage signal is used as a main safety loop, in series with an emergency stop switch module, a BMS fault latching unit, an insulation fault latching unit, and a discharge relay, and additionally leads out 12V as a power supply for the BMS fault latching unit and the insulation fault latching unit, and an outgoing wake-up power supply. Only when the BMS fault latching unit and the insulation fault latching unit do not receive a fault signal, can the electric vehicle to be charged be charged. The main safety loop is connected to a low-voltage power supply end of a power distribution unit (PDU) through a high-voltage interlocking plug, and a loop is formed. During the charging process, as soon as the BMS fault latching unit receives a BMS fault signal and / or the insulation fault latching unit receives an insulation fault signal, the main safety loop is disconnected and the high voltage is disconnected, and the discharge is quickly performed, thereby effectively protecting the charging loop. The emergency stop switch module is used to quickly disconnect the charging loop when an abnormality occurs during the charging process, to ensure the safety of the circuit. The voltage conversion unit, the emergency stop switch module, the BMS fault latching unit, the insulation fault latching unit, and the discharge relay are all modularly designed, to facilitate maintenance and upgrading, and also help to realize miniaturization design and reduce design cost. The plug used to connect the charger and the electric vehicle to be charged is, for example, a high-voltage interlocking plug, and the plug used to connect the charging protection circuit of the portable charger and the electric vehicle to be charged is, for example, an aviation plug.

[0079] The application also provides a protection device comprising the charging protection circuit of the portable charger according to any one 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 the application, the device has the multiple fault protection capability of electronicization and fast response. The device not only can quickly respond to and latch the BMS fault and the insulation fault, significantly reducing the action delay and single-point failure risk of the traditional mechanical protection element, but also realizes the whole-process safety protection from fault detection, quick power-off to safe discharge and state visualization by integrating the functions of discharge and state indication, thereby significantly improving the safety, reliability and maintainability of the entire portable charging system, and providing a key guarantee for high-standard charging scenarios.

[0081] The application also provides a portable charger comprising the charging protection circuit of the portable charger according to any one of the above embodiments, or the portable charger comprises the protection device according to the above embodiments.

[0082] By applying the charging protection circuit or protection device provided in the above embodiments to the portable charger of the present application, the portable charger effectively solves the inherent response delay, protection blind area and single-point failure of the traditional scheme relying on mechanical protection elements, and the charger can monitor, latch and power off quickly in real time for various abnormal states such as BMS failure and insulation failure, and has the functions of safe discharge after failure and state indication, realizes a complete electronic protection closed loop from fault sensing to safe processing, significantly improves the safety, reliability and user experience of the portable charger in complex application environments, and meets the needs of various charging scenes with extremely high safety standards.

[0083] In summary, the present 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 fast response is formed, which effectively reduces the safety hazards caused by the slow action or failure of mechanical elements such as fuses and circuit breakers in related technologies; and the circuit can complete state latching at the moment when the BMS fault signal or insulation fault signal appears, and immediately trigger the charging loop shutdown mechanism, effectively eliminating the inherent time delay of the controller communication, judgment and execution link, realizing millisecond-level fault isolation, and significantly improving the real-time performance and reliability of the charging protection. At the same time, the design significantly reduces the dependence on mechanical protection elements, effectively expands the protection capability for non-overcurrent faults such as battery overcharging, voltage abnormalities and insulation faults, overcomes the traditional protection blind area, and thus fully enhances the safety and operation reliability of the portable charger in complex working conditions, better meeting the needs of current high-reliability charging scenes.

[0085] II. By introducing an emergency stop switch module, a three-protection mechanism combining manual emergency and automatic backup is provided, which not only gives the operator the ability to intervene actively and effectively solves the problem of slow reaction of manual emergency stop, but also as an independent safety barrier, when the BMS failure protection fails or the insulation failure protection fails, it can intervene and forcibly cut off the working power of the entire system in a very short time, thereby significantly improving the redundancy and reliability of the entire charging protection circuit.

[0086] III. By introducing the discharge relay module, the charging protection circuit of the portable charger can automatically conduct the discharge circuit immediately after the fault is disconnected, the residual high voltage energy on the charger output and DC bus is quickly discharged through the discharge resistor and converted into heat energy consumption, effectively eliminating the residual high voltage of the port after the power failure, significantly reducing the risk of electric shock in subsequent operation, providing key protection for equipment maintenance and personnel safety, and forming a complete safety protection closed loop from fault isolation to energy discharge, significantly improving the overall safety and reliability of the system.

[0087] It should be understood, however, that the scope of the present application is not limited to the specific embodiments illustrated herein, but includes any and all embodiments which come within the scope of the claims.

Claims

1. A charge protection circuit for a portable charger, characterized by, The application relates to a portable charging machine, which comprises a voltage conversion unit, a BMS fault latch unit and an insulation fault latch unit. The voltage conversion unit comprises an input end and an output end, the input end is used for receiving an external alternating-current input voltage signal, the voltage conversion unit is used for converting the external alternating-current input voltage signal into a low-voltage direct-current power supply signal and outputting the low-voltage direct-current power supply signal through the output end. The BMS fault latch unit comprises a first input end, a second input end and a first output end, the first input end is connected with the output end, the second input end is connected with a BMS and is used for receiving a BMS state signal sent by the BMS, the BMS fault latch unit is used for performing latch processing on the BMS fault signal when the BMS state signal is a BMS fault signal and outputting the latch-processed BMS fault signal through the first output end. The first input end of the insulation fault latch unit is connected with the first output end, the second input end of the insulation fault latch unit is connected with an insulation detection plate of the portable charging machine and is used for acquiring an insulation state signal detected by the insulation detection plate, the insulation fault latch unit is used for performing latch processing on the insulation fault signal when the insulation state signal is an insulation fault signal and outputting the latch-processed insulation fault signal through the output end of the insulation fault latch unit, and the output end of the insulation fault latch unit is connected with an electric vehicle to be charged. When the BMS fault latch unit outputs the latch-processed BMS fault signal and / or the insulation fault latch unit outputs the latch-processed insulation fault signal, the charging protection circuit of the portable charging machine is immediately cut off to interrupt the charging of the electric vehicle to be charged. The application further comprises an emergency stop switch module, which is connected in series in the charging protection circuit of the portable charging machine, wherein the input end of the emergency stop switch module is connected with the output end, the output end of the emergency stop switch module is connected with the first input end, and the emergency stop switch module is used for forcibly disconnecting the charging protection circuit of the portable charging machine immediately when a target condition is met, the target condition comprising any one of the following:

2. The charge protection circuit for a portable charger of claim 1, wherein, An operator manually triggers an emergency stop operation; The BMS fault latch unit receives a BMS fault signal, and the charging protection circuit of the portable charging machine is not cut off within a first preset time length; The insulation fault latch unit receives an insulation fault signal, and the charging protection circuit of the portable charging machine is not cut off within a second preset time length. The application further comprises a discharge relay module, the control end of the discharge relay module is connected with the first output end and the output end of the insulation fault latch unit respectively, and the main circuit of the discharge relay module is connected between the output end of the charging machine and a discharge circuit; when the charging protection circuit of the portable charging machine is cut off due to a fault, the discharge relay module turns on a discharge resistor in the discharge circuit to release the residual electric energy of the output end of the charging machine through the discharge resistor.

3. The charge protection circuit for a portable charger of claim 1, wherein, The discharge relay module is a normally closed power relay.

4. The charge protection circuit for a portable charger of claim 3, wherein, ​ 5. The charge protection circuit for a portable charger according to any one of claims 1 to 4, wherein Further comprising a BMS fault signal display unit and an insulation fault signal display unit, wherein: a first end of the BMS fault signal display unit is connected with the first output end, and a second end of the BMS fault signal display unit is grounded, the BMS fault signal display unit is used to send an indication signal of BMS fault when the first output end outputs the BMS fault signal after the latch processing; a first end of the insulation fault signal display unit is connected with the output end of the insulation fault latch unit, and a second end of the insulation fault signal display unit is grounded, the insulation fault signal display unit is used to send an indication signal of insulation fault when the output end of the insulation fault latch unit outputs the insulation fault signal after the latch processing.

6. The charge protection circuit for a portable charger of claim 5, wherein, The BMS fault signal display unit and the insulation fault signal display unit comprise signal indication lamps.

7. The charge protection circuit for a portable charger of any one of claims 1 to 4, wherein The BMS fault latch unit comprises a signal conditioning circuit, a voltage comparator and a reset-set latch, wherein: an input end of the signal conditioning circuit serves as the second input end, and is used to filter and perform level conversion on the received BMS state signal to obtain a processed signal, the processed signal is output through an output end of the signal conditioning circuit; a non-inverting input end of the voltage comparator is connected with the output end of the signal conditioning circuit, and an inverting input end of the voltage comparator is connected with a set voltage threshold, the voltage comparator is used to compare the processed signal with the set voltage threshold to obtain a comparison result, the comparison result is output through an output end of the voltage comparator; a set input end of the reset-set latch is connected with the output end of the voltage comparator, a reset input end of the reset-set latch is connected with a global reset signal, and an output end of the reset-set latch serves as the first output end; when the comparison result represents a BMS state signal as a BMS fault signal, the reset-set latch latches the comparison result as the insulation fault signal after the latch processing, and outputs the insulation fault signal after the latch processing through the first output end until the reset input end receives the global reset signal.

8. The charge protection circuit for a portable charger of any one of claims 1 to 4, wherein, The insulation fault latch unit comprises a differential sampling circuit, an analog-to-digital converter and a digital latch, wherein: an input end of the differential sampling circuit serves as the second input end of the insulation fault latch unit, and is used to collect an insulation state signal output by the insulation detection board, and output a single-ended sampling signal through an output end of the differential sampling circuit; an input end of the analog-to-digital converter is connected with the output end of the differential sampling circuit, the analog-to-digital converter is used to convert the sampling signal into a digital value, and the digital value is output through an output end of the analog-to-digital converter; an input end of the digital latch is connected with the output end of the analog-to-digital converter, and an output end of the digital latch serves as the output end of the insulation fault latch unit; when the insulation state signal represents an insulation fault signal, the digital latch latches the insulation fault signal after the latch processing, and outputs the insulation fault signal after the latch processing through the output end of the insulation fault latch unit until the reset input end receives the global reset signal. The input end of the digital latch is connected to the output end of the analog-digital converter, and the output end of the digital latch serves as the output end of the insulation fault latch unit; when the digital value represents an insulation state signal as an insulation fault signal, the digital latch latches the digital value as a latched insulation fault signal, and outputs the latched insulation fault signal through the output end of the insulation fault latch unit.

9. A protection device, characterized in that A charging protection circuit comprising a portable charger as claimed in any one of claims 1 to 8.

10. A portable charging machine characterized by, A protection device as claimed in claim 9.

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