Automobile charging health diagnosis and protection module, device and equipment

Abstract

The embodiment of the application relates to the field of circuit protection, and provides a car charging health diagnosis and protection module, device and equipment, which comprise a leakage current CT, a leakage current three-stage detection circuit, a phase current CT, a current impact three-stage detection circuit, a first temperature sensor, a second temperature sensor, a temperature difference three-stage detection circuit, a first switch and a switch control module, the output end of the leakage current CT is connected with the input end of the leakage current three-stage detection circuit, the output end of the phase current CT is connected with the input end of the current impact three-stage detection circuit, the output ends of the leakage current three-stage detection circuit and the current impact three-stage detection circuit are connected with the input end of the switch control module; the output ends of the first temperature sensor and the second temperature sensor are connected with the input end of the temperature difference three-stage detection circuit, the output end of the temperature difference three-stage detection circuit is connected with the input end of the switch control module; and the output end of the switch control module is connected with the first switch, so that the accuracy during abnormal protection is improved.

Description

Technical Field

[0001] This application relates to the field of circuit protection technology, specifically to a vehicle charging health diagnosis and protection module, device, and equipment. Background Technology

[0002] As electric vehicles (EVs) mature, their user base and market size are expanding annually. Direct charging, a crucial method for EV power acquisition, relies heavily on the charging current, which is a key variable determining charging speed and safety. However, the limited current monitoring and protection capabilities of existing charging pile switches prevent comprehensive monitoring of the charging process. Furthermore, issues such as EV battery quality, internal short circuits, overcharging / over-discharging, charging equipment malfunctions, improper charging pile installation, damaged charging nozzles, damaged charging cables, loose plugs, poor or intermittent wiring connections, and aging equipment and wiring contribute to an increasing trend of EV charging anomalies and fires. Simultaneously, rectifier failures in the EV charging control module and abnormal charging circuits pose significant safety hazards, creating instability for society and residents' property. This also places immense pressure on the daily operation and maintenance of power grid companies' distribution network marketing equipment, severely impacting user electricity experience and the image of power grid companies.

[0003] Current leakage protection devices only have single-stage leakage tripping, typically 30mA, which cannot distinguish early warning of insulation degradation; the overcurrent protection of circuit breakers is delayed or unable to protect against abnormal instantaneous large current surges; temperature protection alarm devices only monitor the absolute value of ambient temperature or device temperature, without considering the actual temperature rise of the conductors, resulting in low reliability when performing abnormal protection. Utility Model Content

[0004] This application provides a car charging health diagnosis and protection module, device, and equipment. By designing three detection circuits and controlling the first switch through a switch control module based on the output signals of the three detection circuits, the accuracy of abnormal protection is improved.

[0005] A first aspect of this application provides a vehicle charging health diagnosis and protection module. The module includes a leakage current CT, a three-level leakage current detection circuit, a phase current CT, a three-level current surge detection circuit, a first temperature sensor, a second temperature sensor, a three-level temperature difference detection circuit, a first switch, and a switch control module.

[0006] The leakage current CT has a primary side that connects the live wire L and the neutral wire N, and the live wire L and the neutral wire N are connected to the car charging pile through the first switch.

[0007] The output terminal of the leakage current CT is connected to the input terminal of the three-stage leakage current detection circuit, and the output terminal of the three-stage leakage current detection circuit is connected to the first input terminal of the switch control module.

[0008] The phase current CT is mounted on the live wire L. The output terminal of the phase current CT is connected to the input terminal of the current surge three-stage detection circuit. The output terminal of the current surge three-stage detection circuit is connected to the second input terminal of the switch control module.

[0009] The output terminal of the first temperature sensor is connected to the first input terminal of the three-stage temperature difference detection circuit, the output terminal of the second temperature sensor is connected to the second input terminal of the three-stage temperature difference detection circuit, and the output terminal of the three-stage temperature difference detection circuit is connected to the third input terminal of the switch control module.

[0010] The output terminal of the switch control module is connected to the control terminal of the first switch.

[0011] In one possible implementation, the three-stage leakage current detection circuit includes: a first rectifier bridge, a filter sub-circuit, and a three-stage voltage divider circuit. The output terminal of the first rectifier bridge is connected to the input terminal of the filter sub-circuit, the output terminal of the filter sub-circuit is connected to the non-inverting input terminal of the three-stage voltage divider circuit, the three inverting input terminals of the three-stage voltage divider circuit are respectively connected to a first reference signal, a second reference signal, and a third reference signal, the voltage amplitudes of the first reference signal, the second reference signal, and the third reference signal are different, and the output terminal of the three-stage voltage divider circuit is connected to the first input terminal of the switch control module.

[0012] In one possible implementation, the filter sub-circuit includes an RC low-pass filter circuit.

[0013] In one possible implementation, the three-stage current surge detection circuit includes a sampling resistor, a second rectifier bridge, and a peak hold sub-circuit, wherein,

[0014] The input terminal of the second rectifier bridge is connected to the output terminal of the phase current CT through the sampling resistor. The output terminal of the second rectifier bridge is connected to the input terminal of the peak hold sub-circuit. The output terminal of the peak hold sub-circuit is connected to the second input terminal of the switch control module.

[0015] In one possible implementation, the three-stage temperature difference detection circuit includes: a Wheatstone bridge, a differential amplifier sub-circuit, and a comparator sub-circuit, wherein,

[0016] The output of the first temperature sensor is connected to the first arm of the Wheatstone bridge, the output of the second temperature sensor is connected to the second arm of the Wheatstone bridge, the output of the Wheatstone bridge is connected to the input of the differential amplifier sub-circuit, the output of the differential amplifier sub-circuit is connected to the input of the comparator sub-circuit, and the output of the comparator sub-circuit is connected to the third input of the switch control module.

[0017] In one possible implementation, the vehicle charging health diagnosis and protection module further includes an LED driver matrix, with the first input terminal of the LED driver matrix connected to the output terminal of the leakage current three-level detection circuit, the second input terminal of the LED driver matrix connected to the output terminal of the current surge three-level detection circuit, and the third input terminal of the LED driver matrix connected to the output terminal of the temperature difference three-level detection circuit.

[0018] In one possible implementation, the switch control module includes a first RC delay sub-circuit, a second RC delay sub-circuit, a third RC delay sub-circuit, and a magnetic latching relay, wherein the output terminals of the first RC delay sub-circuit, the second RC delay sub-circuit, and the third RC delay sub-circuit are connected to the control terminal of the magnetic latching relay, and the output terminal of the magnetic latching relay is connected to the first switch.

[0019] In one possible implementation, the delay duration of the first RC delay sub-circuit is 400 seconds, the delay duration of the second RC delay sub-circuit is 60 seconds, and the delay duration of the third RC delay sub-circuit is 0 seconds.

[0020] A second aspect of this application provides an automotive charging health diagnosis and protection device, including a circuit board and an automotive charging health diagnosis and protection module as described in any one of the first aspects, wherein the automotive charging health diagnosis and protection module is disposed on the circuit board.

[0021] A third aspect of this application provides an automotive charging health diagnostic and protection device, including a housing and an automotive charging health diagnostic and protection device as described in the second aspect, wherein the automotive charging health diagnostic and protection device is disposed within the housing.

[0022] Implementing the embodiments of this application has the following beneficial effects:

[0023] The vehicle charging health diagnosis and protection module includes a leakage current CT, a three-level leakage current detection circuit, a phase current CT, a three-level current surge detection circuit, a first temperature sensor, a second temperature sensor, a three-level temperature difference detection circuit, a first switch, and a switch control module. Therefore, by designing three detection circuits and controlling the first switch through the switch control module based on the output signals of the three detection circuits, the accuracy of abnormal protection is improved. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This application provides a schematic diagram of the structure of an automotive charging health diagnosis and protection module.

[0026] Figure 2 This application provides a schematic diagram of a three-stage leakage current detection circuit for an embodiment.

[0027] Figure 3 This application provides a schematic diagram of a three-stage current surge detection circuit.

[0028] Figure 4 This application provides a schematic diagram of a three-stage temperature difference detection circuit.

[0029] Figure 5 This application provides a schematic diagram of the structure of a switch control module. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0032] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0033] Please see Figure 1 , Figure 1 This application provides a schematic diagram of the structure of an automotive charging health diagnosis and protection module. Figure 1 As shown, the module includes a leakage current CT1, a three-stage leakage current detection circuit 2, a phase current CT3, a three-stage current surge detection circuit 4, a first temperature sensor 5, a second temperature sensor 6, a three-stage temperature difference detection circuit 7, a first switch 8, and a switch control module 9.

[0034] The leakage current CT1 is connected to the live wire L and the neutral wire N on the primary side, and the live wire L and the neutral wire N are connected to the car charging pile through the first switch.

[0035] The output terminal of the leakage current CT1 is connected to the input terminal of the three-stage leakage current detection circuit, and the output terminal of the three-stage leakage current detection circuit 2 is connected to the first input terminal of the switch control module.

[0036] The phase current CT is mounted on the live wire L. The output terminal of the phase current CT3 is connected to the input terminal of the current surge three-stage detection circuit 4. The output terminal of the current surge three-stage detection circuit 4 is connected to the second input terminal of the switch control module 9.

[0037] The output terminal of the first temperature sensor 5 is connected to the first input terminal of the three-stage temperature difference detection circuit, the output terminal of the second temperature sensor 6 is connected to the second input terminal of the three-stage temperature difference detection circuit 7, and the output terminal of the three-stage temperature difference detection circuit 7 is connected to the third input terminal of the switch control module 9.

[0038] The output terminal of the switch control module 9 is connected to the control terminal of the first switch 8.

[0039] The first temperature sensor 5 is attached to a wire, and the second temperature sensor 6 is attached to the outside of the housing. The voltage is directly connected to the power module within the module, which outputs 12V / 300mA DC to power subsequent circuits. Examples include the leakage current three-stage detection circuit 22, the current surge three-stage detection circuit 44, the first temperature sensor 55, the second temperature sensor 6, the temperature difference three-stage detection circuit 77, the first switch 8, and the switch control module 99.

[0040] In this example, by designing three detection circuits and controlling the first switch 8 through the switch control module 9 based on the output signals of the three detection circuits, the accuracy of abnormal protection is improved.

[0041] In one possible implementation, such as Figure 2 As shown, the three-stage leakage current detection circuit 2 includes: a first rectifier bridge 21, a filter sub-circuit 22, and a three-stage voltage divider circuit 23. The output terminal of the first rectifier bridge 21 is connected to the input terminal of the filter sub-circuit 22, the output terminal of the filter sub-circuit 22 is connected to the non-inverting input terminal of the three-stage voltage divider circuit 23, the three inverting input terminals of the three-stage voltage divider circuit 23 are respectively connected to a first reference signal, a second reference signal, and a third reference signal, the voltage amplitudes of the first reference signal, the second reference signal, and the third reference signal are different, and the output terminal of the three-stage voltage divider circuit 23 is connected to the first input terminal of the switch control module 9.

[0042] Among them, the filter sub-circuit 22 includes an RC low-pass filter circuit.

[0043] Specifically, under normal, non-leakage conditions, the currents flowing through the live wire L and the neutral wire N are equal in magnitude and opposite in direction, and their magnetic fields cancel each other out, so the secondary coil of the leakage current CT1 has no induced signal. When leakage occurs, the vector sum of the currents is not equal to zero, and the secondary coil induces an AC voltage signal proportional to the magnitude of the leakage current. The output signal of the secondary coil of the leakage current CT1 first passes through the first rectifier bridge 21, converting it into a unidirectional pulsating DC signal, and then passes through a filter sub-circuit 22 (RC low-pass filter circuit) for smoothing, finally obtaining a smooth DC voltage signal V_leak proportional to the effective value of the leakage current. The RC low-pass filter circuit and the first rectifier bridge 21 can adopt a general circuit structure.

[0044] The three-stage voltage divider circuit 23 uses three comparators U1a, U1b, and U1c from a four-channel voltage comparator integrated circuit. Through voltage dividing resistors, it divides the stable reference voltage Vref, such as 5V, to generate three fixed reference voltages, which correspond to three leakage thresholds (i.e., three reference signals).

[0045] V_ref1 (first reference signal): 1V, corresponding to leakage current level L1, 10mA, warning threshold, corresponding to alarm level L1.

[0046] V_ref2 (Second Reference Signal): 2V, corresponding to leakage current level L2, 20mA, critical alarm threshold, corresponding to alarm level L2.

[0047] V_ref3 (Third Reference Signal): 3V, corresponding to leakage current level L3, 30mA, fault trip threshold, corresponding to alarm level L3.

[0048] The processed leakage voltage signal V_leak is simultaneously sent to the non-inverting input terminals of three comparators, and the three inverting input terminals are connected to V_ref1, V_ref2 and V_ref3 respectively.

[0049] When V_leak < V_ref1, all comparators output a low level.

[0050] When V_ref1 ≤ V_leak < V_ref2, only U1a outputs a high level, triggering a level L1 early warning for leakage current.

[0051] When V_ref2 ≤ V_leak < V_ref3, U1a and U1b output high levels, triggering a level L2 alarm for leakage current.

[0052] When V_leak ≥ V_ref3, U1a, U1b and U1c all output high levels, triggering a level L3 tripping for leakage current.

[0053] In a possible implementation, as Figure 3 shown, the three-stage current impact detection circuit 4 includes a sampling resistor 41, a second rectifier bridge 42 and a peak holding sub-circuit 43, wherein

[0054] The input terminal of the second rectifier bridge is connected to the output terminal of the phase current CT3 through the sampling resistor, the output terminal of the second rectifier bridge is connected to the input terminal of the peak holding sub-circuit, and the output terminal of the peak holding sub-circuit is connected to the second input terminal of the switch control module 9.

[0055] Wherein, the phase current CT3 is sleeved on the live line L and is configured to monitor the total current of the charging circuit. The alternating current signal induced by the secondary side of the phase current CT3 first flows through a sampling resistor and is converted into an alternating voltage signal. The signal is converted into a unidirectional pulsating voltage through the second rectifier bridge, and then connected to a peak holding sub-circuit to output a peak voltage V_peak.

[0056] Similar to leakage detection, another group of three comparators (U2a, U2b, U2c) is used in the peak holding sub-circuit. The reference voltages are calibrated according to the CT transformation ratio and circuit amplification factor, and are set as follows:

[0057] V_ref_peak1: 2.7V, corresponding to level L1 current impact, 45A, early warning threshold, corresponding to alarm level L1.

[0058] V_ref_peak2: 4.2V, corresponding to level L2 current impact, 70A, serious alarm threshold, corresponding to alarm level L2.

[0059] V_ref_peak3: 6.0V, corresponding to current surge level L3, 100A, fault trip threshold, corresponding to alarm level L3.

[0060] The voltage signal V_peak, representing the peak current, is compared with these three reference voltages. The output logic is exactly the same as that of the leakage current detection circuit, realizing the three-level judgment of current surge.

[0061] In one possible implementation, such as Figure 4 As shown, the three-stage temperature difference detection circuit 7 includes: a Wheatstone bridge 71, a differential amplifier sub-circuit 72, and a comparator sub-circuit 73, wherein...

[0062] The output of the first temperature sensor 5 is connected to the first arm of the Wheatstone bridge 71, the output of the second temperature sensor 6 is connected to the second arm of the Wheatstone bridge 71, the output of the Wheatstone bridge 71 is connected to the input of the differential amplifier sub-circuit 72, the output of the differential amplifier sub-circuit 72 is connected to the input of the comparator sub-circuit 73, and the output of the comparator sub-circuit 73 is connected to the third input of the switch control module 9. The Wheatstone bridge, differential amplifier circuit, and comparator circuit can employ a common circuit structure.

[0063] Two negative temperature coefficient thermistors (NTCs) are used: a first temperature sensor 5 (whose temperature value is denoted as R_ntc_wire) is tightly fixed to the insulation of the main cable of the charging circuit to sense the wire temperature; and a second temperature sensor 6 (whose temperature value is denoted as R_ntc_amb) is installed on the outer casing of the module away from the heat-generating components to sense the ambient temperature. The first and second temperature sensors 5 and 6 are placed on two adjacent arms of a Wheatstone bridge 71. The bridge is powered by a stable reference voltage Vref (via a power supply module).

[0064] When the temperature of the live wire L is the same as the ambient temperature, the bridge is in equilibrium, and the output differential voltage V_diff is zero. When the live wire L heats up due to overcurrent, excessive contact resistance, or other reasons, the resistance change of R_ntc_wire exceeds R_ntc_amb, the bridge becomes unbalanced, and outputs a small voltage signal V_diff that is proportional to the temperature difference ΔT. The differential voltage V_diff output by the Wheatstone bridge 71 is fed into a differential amplifier sub-circuit 72 composed of an operational amplifier for amplification, resulting in a voltage signal V_temp_diff of sufficient amplitude, the magnitude of which directly represents the temperature difference between the wire and the environment.

[0065] Using a set of three comparators (U3a, U3b, U3c) in comparator sub-circuit 73, the reference voltage is calibrated according to the characteristics and amplification factor of the NTC (specifically, a general calibration method can be used for calibration), and is set as follows:

[0066] V_ref_temp1 (corresponding to U3a): 1.0V, corresponding to temperature difference level L1, ΔT=30℃, warning threshold, corresponding to alarm level L1.

[0067] V_ref_temp2 (corresponding to U3b): 1.7V, corresponding to temperature difference level L2, ΔT=50℃, critical alarm threshold, corresponding to alarm level L2.

[0068] V_ref_temp3 (corresponding to U3c): 2.3V, corresponding to temperature difference level L3, ΔT=70℃, fault trip threshold, corresponding to alarm level L3.

[0069] The amplified temperature difference voltage signal V_temp_diff is compared with the three reference voltages. The output logic is exactly the same as that of the leakage current detection circuit. The output logic controls the subsequent indication and switch control module 9.

[0070] In one possible implementation, such as Figure 1 As shown, the vehicle charging health diagnosis and protection module also includes an LED driver matrix 10. The first input terminal of the LED driver matrix 10 is connected to the output terminal of the leakage current three-level detection circuit, the second input terminal of the LED driver matrix 10 is connected to the output terminal of the current surge three-level detection circuit 4, and the third input terminal of the LED driver matrix 10 is connected to the output terminal of the temperature difference three-level detection circuit 7.

[0071] A row-column scanning approach is used to statically drive and display a 3 (fault type) × 3 (severity level) LED matrix, showing only the highest level alarm. Input signals are encoded by a 74HC148 circuit to ensure that only the highest level alarm signal of the same type is valid. A 74HC238 decoder converts the three fault types into enable signals for three row lines. The row and column signals are amplified by a ULN2003 driver array to control the LED matrix; when a row line is high and a column line is low, the corresponding LED at the intersection lights up.

[0072] In one possible implementation, such as Figure 5As shown, the switch control module 9 includes a first RC delay sub-circuit 91, a second RC delay sub-circuit 92, a third RC delay sub-circuit 93, and a magnetic latching relay 94. The output terminals of the first RC delay sub-circuit 91, the second RC delay sub-circuit 92, and the third RC delay sub-circuit 93 are connected to the control terminal of the magnetic latching relay 94, and the output terminal of the magnetic latching relay 94 is connected to the first switch 8.

[0073] The first RC delay sub-circuit 91 has a delay duration of 400 seconds, the second RC delay sub-circuit 92 has a delay duration of 60 seconds, and the third RC delay sub-circuit 93 has a delay duration of 0 seconds. The RC delay sub-circuits can adopt a common RC circuit structure.

[0074] Specifically, based on alarm levels L1 / L2 / L3, the switch control module 9 executes differentiated delayed trip control, ultimately driving the magnetic latching relay 94 to cut off the circuit. The L1 / L2 paths use an RC integrator circuit to achieve the delay. By adjusting the values ​​of resistor R and capacitor C, the charging time is precisely set, achieving a delay of 400s for L1 and 60s for L2. The L3 path has a 0-second delay, using a direct channel for rapid response. A valid trip signal from any channel triggers subsequent actions. The trigger signal is amplified to provide sufficient pulse current to the tripping coil of the magnetic latching relay 94. The magnetic latching relay 94 requires only one pulse to trip, and no further power supply is needed for maintenance, making it energy-efficient and reliable.

[0075] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A vehicle charging health diagnosis and protection module, characterized in that, The module includes a leakage current CT, a three-stage leakage current detection circuit, a phase current CT, a three-stage current surge detection circuit, a first temperature sensor, a second temperature sensor, a three-stage temperature difference detection circuit, a first switch, and a switch control module. The leakage current CT has a primary side that connects the live wire L and the neutral wire N, and the live wire L and the neutral wire N are connected to the car charging pile through the first switch; The output terminal of the leakage current CT is connected to the input terminal of the three-stage leakage current detection circuit, and the output terminal of the three-stage leakage current detection circuit is connected to the first input terminal of the switch control module. The phase current CT is mounted on the live wire L. The output terminal of the phase current CT is connected to the input terminal of the current surge three-stage detection circuit. The output terminal of the current surge three-stage detection circuit is connected to the second input terminal of the switch control module. The output terminal of the first temperature sensor is connected to the first input terminal of the three-stage temperature difference detection circuit, the output terminal of the second temperature sensor is connected to the second input terminal of the three-stage temperature difference detection circuit, and the output terminal of the three-stage temperature difference detection circuit is connected to the third input terminal of the switch control module. The output terminal of the switch control module is connected to the control terminal of the first switch.

2. The vehicle charging health diagnosis and protection module according to claim 1, characterized in that, The three-stage leakage current detection circuit includes: a first rectifier bridge, a filter sub-circuit, and a three-stage voltage divider circuit. The output terminal of the first rectifier bridge is connected to the input terminal of the filter sub-circuit, the output terminal of the filter sub-circuit is connected to the non-inverting input terminal of the three-stage voltage divider circuit, the three inverting input terminals of the three-stage voltage divider circuit are respectively connected to a first reference signal, a second reference signal, and a third reference signal, the voltage amplitudes of the first reference signal, the second reference signal, and the third reference signal are different, and the output terminal of the three-stage voltage divider circuit is connected to the first input terminal of the switch control module.

3. The vehicle charging health diagnosis and protection module according to claim 2, characterized in that, The filter sub-circuit includes an RC low-pass filter circuit.

4. The vehicle charging health diagnosis and protection module according to claim 3, characterized in that, The three-stage current surge detection circuit includes a sampling resistor, a second rectifier bridge, and a peak hold sub-circuit, wherein... The input terminal of the second rectifier bridge is connected to the output terminal of the phase current CT through the sampling resistor. The output terminal of the second rectifier bridge is connected to the input terminal of the peak hold sub-circuit. The output terminal of the peak hold sub-circuit is connected to the second input terminal of the switch control module.

5. The vehicle charging health diagnosis and protection module according to claim 4, characterized in that, The three-stage temperature difference detection circuit includes: a Wheatstone bridge, a differential amplifier sub-circuit, and a comparator sub-circuit, wherein... The output of the first temperature sensor is connected to the first arm of the Wheatstone bridge, the output of the second temperature sensor is connected to the second arm of the Wheatstone bridge, the output of the Wheatstone bridge is connected to the input of the differential amplifier sub-circuit, the output of the differential amplifier sub-circuit is connected to the input of the comparator sub-circuit, and the output of the comparator sub-circuit is connected to the third input of the switch control module.

6. The vehicle charging health diagnosis and protection module according to any one of claims 1-5, characterized in that, The vehicle charging health diagnosis and protection module also includes an LED driver matrix. The first input terminal of the LED driver matrix is ​​connected to the output terminal of the leakage current three-level detection circuit, the second input terminal of the LED driver matrix is ​​connected to the output terminal of the current surge three-level detection circuit, and the third input terminal of the LED driver matrix is ​​connected to the output terminal of the temperature difference three-level detection circuit.

7. The vehicle charging health diagnosis and protection module according to claim 6, characterized in that, The switch control module includes a first RC delay sub-circuit, a second RC delay sub-circuit, a third RC delay sub-circuit, and a magnetic latching relay. The output terminals of the first RC delay sub-circuit, the second RC delay sub-circuit, and the third RC delay sub-circuit are connected to the control terminal of the magnetic latching relay, and the output terminal of the magnetic latching relay is connected to the first switch.

8. The vehicle charging health diagnosis and protection module according to claim 7, characterized in that, The delay duration of the first RC delay sub-circuit is 400 seconds, the delay duration of the second RC delay sub-circuit is 60 seconds, and the delay duration of the third RC delay sub-circuit is 0 seconds.

9. A vehicle charging health diagnosis and protection device, characterized in that, The device includes a circuit board and a vehicle charging health diagnosis and protection module as described in any one of claims 1-8, wherein the vehicle charging health diagnosis and protection module is disposed on the circuit board.

10. A vehicle charging health diagnosis and protection device, characterized in that, It includes a housing and a vehicle charging health diagnostic and protection device as described in claim 9, wherein the vehicle charging health diagnostic and protection device is disposed within the housing.

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