Insulation detection apparatus and method, and charging pile

Abstract

Disclosed in the present application are an insulation detection apparatus and method, and a charging pile. The apparatus comprises: a first sampling unit and a second sampling unit that are provided on a power supply circuit, a first signal processing module connected to the first sampling unit, a second signal processing module connected to the second sampling unit, a detection module connected to the first signal processing module and second signal processing module, and a signal source and a reference source, wherein the signal source is used for injecting a voltage into a power supply ground wire; the reference source is used for outputting a fixed voltage; the first signal processing module is used for acquiring a first sampling voltage on the first sampling unit and a corresponding first amplified voltage; the second signal processing module is used for acquiring a second sampling voltage on the second sampling unit and a corresponding second amplified voltage; and on the basis of the first sampling voltage and the corresponding first amplified voltage, and the second sampling voltage and the corresponding second amplified voltage, the detection module determines the insulation of the power supply circuit. By using the solution of the present application, high-precision and real-time insulation detection can be implemented on a high-voltage power supply circuit, thereby ensuring the safety of power supply.

Description

Insulation detection device and method, charging pile

[0001] The present application claims priority to the Chinese patent application No. 202411101734.9, filed on August 9, 2024, and entitled "Insulation detection device and method, charging pile", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of circuit, in particular to an insulation detection device and method, charging pile. BACKGROUND

[0003] With the rapid popularization of electric vehicles, people's requirements for safe energy transmission are also getting higher and higher. Charging piles are used outdoors for a long time, and with the alternation of different weather conditions such as high temperature and low temperature, the insulation performance of the charging pile may decrease over time. When the insulation performance decreases to a certain extent, leakage current will be generated during the use of the charging pile, and the leakage current will flow through the human body to the ground, which will pose a danger to personal safety. Therefore, during the charging process of new energy vehicles, it is necessary to detect the impedance value of the transmission system to the ground in real time, and when low impedance is detected, the charging is disconnected in time to protect personal safety. SUMMARY

[0004] The present application provides an insulation detection device and method, charging pile, to realize real-time insulation detection of the power supply circuit and improve the insulation detection accuracy.

[0005] To this end, the present application provides the following technical solutions:

[0006] In one aspect, the present application provides an insulation detection device, comprising: a first sampling unit and a second sampling unit arranged on a power supply circuit, a first signal processing module, a second signal processing module, a detection module, and a signal source and a reference source; the negative terminal of the signal source and the negative terminal of the reference source are connected to a signal ground, the positive terminal of the signal source is connected to a power supply ground wire, and the positive terminal of the reference source is connected to the first sampling unit and the second sampling unit respectively;

[0007] The signal source is configured to inject a voltage into the power supply ground wire.

[0008] The reference source is configured to output a fixed voltage.

[0009] The first signal processing module is configured to obtain a first sampling voltage U1 on the first sampling unit and a corresponding first amplified voltage U2.

[0010] The second signal processing module is configured to obtain a second sampling voltage U3 on the second sampling unit and a corresponding second amplified voltage U4.

[0011] The detection module is configured to determine a first voltage from a first sampling voltage U1 on the first sampling unit and a corresponding first amplified voltage U2, and determine a second voltage from a second sampling voltage U3 on the second sampling unit and a corresponding second amplified voltage U4, and determine the insulation of the power supply loop according to the first voltage and the second voltage.

[0012] Optionally, the first signal processing module comprises:

[0013] The first voltage acquisition unit is configured to acquire the first sampling voltage U1 on the first sampling unit and output the first sampling voltage U1 to the detection module.

[0014] The first voltage amplification unit is configured to amplify the first sampling voltage U1 and output a first amplified voltage U2 to the detection module.

[0015] The second signal processing module comprises:

[0016] The second voltage acquisition unit is configured to acquire the second sampling voltage U3 on the second sampling unit and output the second sampling voltage U3 to the detection module.

[0017] The second voltage amplification unit is configured to amplify the second sampling voltage U3 and output a second amplified voltage U4 to the detection module.

[0018] Optionally, the first voltage acquisition unit and the second voltage acquisition unit are voltage followers.

[0019] Optionally, the first voltage amplification unit and the second voltage amplification unit are operational amplifiers.

[0020] Optionally, the detection module is configured to calculate the ground resistance across the power supply loop according to the first voltage and the second voltage, and determine the insulation of the power supply loop according to the ground resistance across the power supply loop.

[0021] Optionally, the resistance values of the first sampling unit and the second sampling unit are equal.

[0022] Optionally, the output voltage of the reference source is 0-5V.

[0023] Optionally, the signal source outputs a square wave signal.

[0024] In another aspect, the application also provides a charging pile comprising the insulation detection device.

[0025] In another aspect, the application also provides an insulation detection method, which is used for a power supply circuit, the power supply circuit is provided with a first sampling unit and a second sampling unit, and a signal source and a reference source are connected in mirror between a power supply ground wire and the first sampling unit and the second sampling unit.

[0026] The method comprises:

[0027] When the insulation detection is performed, the signal source injects a voltage into the power supply ground wire of the power supply circuit;

[0028] A first sampling voltage U1 on the first sampling unit and a corresponding first amplification voltage U2 are acquired, and a second sampling voltage U3 on the second sampling unit and a corresponding second amplification voltage U4 are acquired;

[0029] A first voltage is determined according to the first sampling voltage U1 on the first sampling unit and the corresponding first amplification voltage U2, a second voltage is determined according to the second sampling voltage U3 on the second sampling unit and the corresponding second amplification voltage U4, and the insulation of the power supply circuit is determined according to the first voltage and the second voltage.

[0030] Optionally, the insulation of the power supply circuit is determined according to the first voltage and the second voltage, which comprises:

[0031] According to the first voltage and the second voltage, a resistance to ground between the two ends of the power supply circuit is calculated;

[0032] The insulation of the power supply circuit is determined according to the resistance to ground between the two ends of the power supply circuit.

[0033] The insulation detection device and method provided by the application can ensure that high-precision signal acquisition can be realized and the precision of insulation detection is improved in the case that the impedance of the power transmission line to the ground is unbalanced.

[0034] The charging pile provided by the application integrates the above insulation detection device, and can realize high-precision detection of the insulation of the power supply circuit and improve the accuracy of the detection result.

[0035] Further, the charging pile provided by the embodiment of the present application can also detect the voltage outside the gun wire of the charging gun, and better meet the requirements of various detection applications. BRIEF DESCRIPTION OF DRAWINGS

[0036] Fig. 1 is a schematic structural diagram of an insulation detection device provided by an embodiment of the present application;

[0037] Fig. 2 is a schematic structural diagram of an insulation detection device provided by an embodiment of the present application;

[0038] Fig. 3 is a flow chart for determining the voltage on the sampling unit in the insulation detection device provided by an embodiment of the present application;

[0039] Fig. 4 is a schematic structural diagram of a charging pile provided by an embodiment of the present application;

[0040] Fig. 5 is a flow chart of an insulation detection method provided by an embodiment of the present application. DETAILED DESCRIPTION

[0041] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0042] The existing insulation detection schemes such as the bridge method must load a certain voltage value on the bus during the detection process, and different switches need to be closed during the detection process to detect the impedance of the bus to the ground by changing the impedance of the bridge arm. Since most of the switches used in the existing bridge method insulation detection are relay types, the relay contacts are prone to sticking and other failures during long-term on-load switching. Moreover, when the impedance of the transmission line single end or double end to the ground is problematic, the bridge arm voltage is unbalanced, which cannot guarantee the consistency of the sampling accuracy of the upper and lower bridge arms, and affects the insulation detection accuracy.

[0043] Since most of the switches used in the existing bridge method insulation detection are relay types, the relay contacts are prone to sticking and other failures during long-term on-load switching. Moreover, when the impedance of the transmission line single end or double end to the ground is problematic, the bridge arm voltage is unbalanced, which cannot guarantee the consistency of the sampling accuracy of the upper and lower bridge arms, and ultimately leads to poor insulation detection accuracy.

[0044] Therefore, the embodiments of the present application provide an insulation detection device and method. In view of the problem that the voltage value fluctuation range of the sampling unit is large due to the different impedance values of the positive and negative bus impedance R+ and R- of the power transmission line (for example, caused by the single fault of the positive and negative bus or the fault of both), which affects the insulation detection accuracy, the sampling voltage and the corresponding amplification voltage on the sampling unit are obtained respectively, the range of the voltage value at both ends of the sampling unit is determined first, and then the sampling voltage is obtained by using appropriate sampling accuracy, so as to improve the insulation detection accuracy of the power supply circuit.

[0045] As shown in FIG. 1, FIG. 1 is a structure schematic diagram of an insulation detection device provided by an embodiment of the present application.

[0046] The insulation detection device is used in a direct current power supply loop to detect insulation of the direct current power supply loop. DC+ and DC- in FIG. 1 are two output ports of a power loop, which can be positive and negative output ports of a power module for example; DC+_OUT and DC-_OUT are two output ports of a power supply loop, which are used to connect a powered end device to supply power to the powered end device. The powered end device can be an electric vehicle for example. A power switch is usually arranged between the power loop and the power supply loop. After the power switch is turned on, the power loop outputs voltage to the power supply loop, and the power supply loop supplies power to the outside, such as charging the electric vehicle.

[0047] Referring to FIG. 1, the insulation detection device of the embodiment includes a first sampling unit r1 and a second sampling unit r2 arranged on the power supply loop, a first signal processing module 11 connected with the first sampling unit r1, a second signal processing module 12 connected with the second sampling unit r2, a detection module 20 connected with the first signal processing module 11 and the second signal processing module 12, and a signal source Us and a reference source Uref. The negative terminal of the signal source Us and the negative terminal of the reference source Uref are connected with a signal ground, the positive terminal of the signal source Us is connected with a power supply ground PE, and the positive terminal of the reference source Uref is connected with the first sampling unit r1 and the second sampling unit r2 respectively. The power supply ground PE (also referred to as a lightning conductor) is a conductor used to introduce current into the ground. When an electrical device leaks or the voltage is too high, the current enters the ground through the power supply ground.

[0048] The first sampling unit r1 and the second sampling unit r2 can be realized by resistance or current transformer, and for the convenience of description, the realization by resistance is taken as an example in the following description. The sampling resistance can be a resistance with a small resistance value, such as 100Ω-1kΩ.

[0049] Further, in order to avoid excessive current, a voltage dividing resistance R1 and a voltage dividing resistance R2 can be connected in series on the power supply loop, as shown in FIG. 1. The upper bridge arm includes the first voltage dividing resistance R1 and the first sampling unit r1 connected in series, and the lower bridge arm includes the second voltage dividing resistance R2 and the second sampling unit r2 connected in series. The resistance values of the first sampling unit r1 and the second sampling unit r2 can be the same for the convenience of calculation, and the first voltage dividing resistance R1 and the second voltage dividing resistance R2 can be the same or different, such as a resistance greater than or equal to 500kΩ, which is not limited in the embodiment of the present application.

[0050] It should be noted that the positional relationship between the voltage dividing resistors and the sampling units is only schematically described in FIG. 1, and in some embodiments, the first voltage dividing resistor R1 and the second voltage dividing resistor R2 can also be multiple, such as a resistor array formed in a series and / or parallel manner, etc., which is not limited in the embodiments of the present application.

[0051] In the embodiment shown in FIG. 1, the reference source Uref and the signal source Us are mirror connected, that is, the negative terminal of the reference source Uref is connected with the negative terminal of the signal source Us and is connected with the signal ground, and the signal source Us is used to inject a voltage to the power supply ground PE; the reference source Uref is used to output a fixed voltage.

[0052] In some embodiments, the signal source Us can be a signal generator, such as a periodic square wave signal generator, and the amplitude of the square wave signal can be less than or equal to 36V, such as ±12V to ±24V in a specific application. The reference source Uref outputs a fixed voltage U R , such as U R may be 0-5V.

[0053] The first signal processing module 11 is used to obtain the first sampling voltage U1 on the first sampling unit r1 and the corresponding first amplification voltage U2, and output to the ports ADC1 and ADC2 of the detection module 20. The second signal processing module 12 has a similar function as the first signal processing module 11, and is used to obtain the second sampling voltage U3 on the second sampling unit and the corresponding second amplification voltage U4, and output to the ports ADC3 and ADC4 of the detection module 20.

[0054] The detection module 20 is used to determine the first voltage U1' according to the first sampling voltage U1 on the first sampling unit r1 and the corresponding first amplification voltage U2, determine the second voltage U2' according to the second sampling voltage U3 on the second sampling unit r2 and the corresponding second amplification voltage U4, and determine the insulation of the power supply loop according to the first voltage U1' and the second voltage U2'. The first voltage U1' is the actual voltage across the first sampling unit r1, and the second voltage U2' is the actual voltage across the second sampling unit r2.

[0055] Among them, the first voltage U1' judges the size of the first sampling voltage U1 and the first amplification voltage U2, determines the voltage range of the sampling voltage on the first sampling unit r1, and then selects the sampling mode suitable for the voltage range to obtain the voltage on the first sampling unit r1, that is, according to the judgment result, whether to select the voltage based on the port ADC1 as the voltage on the first sampling unit r1, or to select the voltage based on the port ADC2 to calculate the voltage on the first sampling unit r1.

[0056] Similarly, the second voltage U2' is the voltage on the second sampling unit r2 determined after judging the size of the second sampling voltage U3 and the second amplified voltage U4.

[0057] Specifically, the size of the voltage across the sampling unit at this time can be determined by the relationship between the amplified voltage value and the maximum value of the range. For example, in the case where the maximum value (saturation voltage) of the range of ADC2 (amplified voltage value) is 5v, if the voltage of ADC2 is detected to be 5V, it is considered that the voltage of the first sampling unit is large, and after amplification, it may have exceeded the measurement range, therefore, the first sampling voltage U1 obtained by ADC1 can be taken as the first voltage for subsequent insulation calculation.

[0058] It can be understood that, due to the different impedance values of the positive and negative bus bars to ground R+ and R-, and the possibility of single fault or both faults of the positive and negative bus bars, in these cases, there will be a large difference in the voltage across the first sampling unit r1 and the second sampling unit r2, and even the two are not in the same order of magnitude, for example, the voltage across the first sampling unit r1 is microvolts, and the voltage across the second sampling unit r2 is volts. If the same method (i.e. the same sampling accuracy) is used to obtain the sampling voltage on the first sampling unit r1 and the second sampling unit r2, the sampling value will not be accurate enough. In the insulation detection device of the embodiment of the present application, the voltage values of the first sampling unit r1 and the second sampling unit r2 are obtained by two sampling methods respectively, i.e. the following method and the amplification method. It can be understood that the voltage value obtained by the following method is the voltage value itself, and the voltage value obtained by the amplification method is the voltage value obtained after amplification by a certain ratio. Then the values of the following voltage and the amplified voltage are judged. If the voltage across the sampling unit is large, it can be directly sampled to obtain a voltage with high accuracy (i.e. using the following method). If the voltage across the sampling unit is small, it can also be sampled after amplification to obtain a high-precision sampling voltage. It can be understood that when the voltage across the sampling unit is small, direct sampling cannot obtain an accurate voltage value due to the sampling range, for example, the voltage is 158 millivolts, and the voltage range accuracy of the following method is insufficient, which can only obtain a voltage of 0.15V. Therefore, the insulation detection device of the embodiment of the present application can improve the voltage sampling accuracy, and further improve the accuracy of the insulation detection based on the sampling voltage.

[0059] The ground resistances R+ and R- of the power supply circuit can be calculated according to the first voltage U1' and the second voltage U2', and the insulation of the power supply circuit can be determined according to the ground resistances of the power supply circuit.

[0060] The determination of the first voltage U1' and the second voltage U2' will be described in detail later.

[0061] First, the principle of calculating the resistances R+ and R- of the power supply circuit to ground according to the first voltage U1' and the second voltage U2' will be described in detail.

[0062] When the insulation detection is performed, the reference source Uref outputs a fixed voltage U R , and the signal source Us outputs different voltages U1 and U2 respectively to change the voltage of the circuit and perform real-time insulation detection. The insulation detection principle is as follows:

[0063] When the signal source Us inputs the voltage U1 to the power supply ground PE, the voltage across the first sampling unit r1 is U r1 , and the voltage across the second sampling unit r2 is U r2 According to the Kirchhoff's current law, that is, at any node in the circuit, the sum of the currents flowing into the node at any time is equal to the sum of the currents flowing out of the node, formula (1) can be obtained:

[0064] Similarly, when the signal source Us inputs the voltage U2 to the power supply ground PE, the voltage across the first sampling unit r1 is U r3 , and the voltage across the second sampling unit r2 is U r4 According to the Kirchhoff's current law, formula (2) can be obtained:

[0065] Wherein, U r1 and U r2 refer to the first voltage U1' and the second voltage U2' obtained by the above sampling method when the signal source Us outputs the voltage U1; U r3 and U r4 refer to the first voltage U1' and the second voltage U2' obtained by the above sampling method when the signal source Us outputs the voltage U2.

[0066] Solving the above formulas (1) and (2) jointly, the resistances R+ and R- of the output ends DC+_OUT and DC-_OUT of the power supply circuit to the power supply ground PE, that is, the resistances of the output ends DC+ and DC- of the power circuit to the power supply ground PE, can be calculated. According to the resistance values of the resistances R+ and R-, the insulation performance of the power supply circuit can be determined.

[0067] For example, when the insulation detection device provided by the embodiment of the present application is applied to a charging pile, the insulation performance of the charging pile can be determined according to the real-time charging voltage U of the vehicle and the above resistances R+ and R- calculated by detection, and further, whether the vehicle continues to charge and other operations can be controlled.

[0068] For example, in some standards, there can be the following judgments and operations:

[0069] If And The vehicle can be normally charged;

[0070] If Or It indicates that the insulation performance in the charging pile is reduced, such as the charging pile insulation alarm can be performed;

[0071] If Or Determine that the charging pile insulation has a problem, and prohibit charging.

[0072] As shown in FIG. 2, it is a specific structure diagram of an insulation detection device provided by the embodiment of the application.

[0073] In this embodiment, power switches K1 and K2 are arranged between the power circuit and the power supply circuit. After the power switches K1 and K2 are closed, the power circuit outputs a voltage to the power supply circuit, and the power supply circuit supplies power to the outside, such as charging an electric vehicle.

[0074] In this embodiment, the first signal processing module includes a first voltage acquisition unit IC_A and a first voltage amplification unit IC_B. Wherein: the first voltage acquisition unit IC_A is used to acquire the first sampling voltage U1 on the first sampling unit r1, and output the first sampling voltage U1 to the detection module 20; the first voltage amplification unit IC_B is used to amplify the first sampling voltage U1, and output the first amplified voltage U2 to the detection module 20.

[0075] Similarly, the second signal processing module includes a second voltage acquisition unit IC_C and a second voltage amplification unit IC_D. Wherein: the second voltage acquisition unit IC_C is used to acquire the second sampling voltage U3 on the second sampling unit r2, and output the second sampling voltage U3 to the detection module 20; the second voltage amplification unit IC_D is used to amplify the second sampling voltage U3, and output the second amplified voltage U4 to the detection module 20.

[0076] The first voltage acquisition unit IC_A and the second voltage acquisition unit IC_C can be implemented by using a voltage follower.

[0077] The first voltage amplification unit IC_B and the second voltage amplification unit IC_D can be implemented by using an operational amplifier. As shown in FIG. 2, the first voltage amplification unit IC_B realizes amplification of the input voltage, i.e. the first sampling voltage U1, by using the voltage dividing resistors R3 and R4; the second voltage amplification unit IC_D realizes amplification of the input voltage, i.e. the second sampling voltage U2, by using the voltage dividing resistors R5 and R6.

[0078] In this embodiment, the voltage across the first sampling unit r1 is output to the port ADC1 of the detection module 20 through the first voltage acquisition unit IC_A in a voltage follower mode, and is output to the port ADC2 of the detection module 20 through the first voltage amplification unit IC_B after being amplified by the resistors R3 and R4.

[0079] The detection module 20 can simultaneously acquire the voltage values of the ports ADC1 and ADC2. By judging the voltage values of the ports ADC1 and ADC2, the voltage value range of the first sampling unit r1 is confirmed, and then the voltage value of the port ADC1 or the port ADC2 is selected to determine the voltage across the first sampling unit r1 to obtain the first voltage U1'.

[0080] Accordingly, based on the above principle, a process for determining the voltage across the first sampling unit r1, i.e., the first voltage U1' described above, is shown in FIG. 3. ADC1 and U ADC2

[0081] In step 301, the voltages U ADC1 and U ADC2 .

[0082] In step 302, it is judged whether the voltage value of U ADC2 is equal to a set value. The set value can be determined according to the saturation voltage of the amplification circuit (i.e., the first voltage amplification unit IC_B in FIG. 2). For example, if the saturation voltage of the amplification circuit is 5V, the set value is 5V.

[0083] If yes, it indicates that the voltage across the first sampling unit r1 is large, the amplification circuit is saturated, the first sampling unit r1 is a large resistance, and the voltage signal across the first sampling unit r1 is strong. At this time, the voltage output by the follower circuit (i.e., the first voltage acquisition unit IC_A in FIG. 2) can be used for calculation, and step 303 is executed. Otherwise, it indicates that the voltage across the first sampling unit r1 is small. At this time, the voltage output by the amplification circuit can be used for calculation to obtain a more accurate sampling voltage, and step 304 is executed.

[0084] It should be noted that the amplification coefficient of the amplification circuit can be selected according to the saturation voltage of the amplification circuit and the detection accuracy. For example, if the accuracy requirement of the sampling voltage is (1uV-1V), the amplification coefficient can be set to 6-10.

[0085] In step 303, the voltage value of the first sampling unit r1 is determined as U ADC1 -U2.

[0086] Step 304, the voltage value of the first sampling unit r1 is determined as: (R3 / (R3+R4) x (U ADC2 -U2)).

[0087] Similarly, the voltage across the second sampling unit r2 is connected to the port ADC3 of the detection module 20 through the second voltage acquisition unit IC_C and the voltage follower, and is connected to the port ADC4 of the detection module 20 through the second voltage amplification unit IC_D and the resistors R5 and R6. The detection module 20 can simultaneously acquire the voltage values of the ports ADC3 and ADC4. By judging the voltage values of the current ports ADC3 and ADC4, it is determined whether the voltage range across the second sampling unit r2 is the first range or the second range. If it is determined that the voltage range is the first range, it means that the voltage signal across the second sampling unit r2 is weak at this time, and the voltage value of the second sampling unit r2 needs to be collected by amplifying it through the amplification circuit of the second voltage amplification unit IC_D. If it is determined that the voltage range is the second range, it means that the voltage signal across the second sampling unit r2 is strong at this time, and the voltage value of the second sampling unit r2 can be collected through the follower circuit of the second voltage acquisition unit IC_C.

[0088] The voltage collection across the second sampling unit r2 is the same as the voltage collection across the first sampling unit r1, and the voltage range judgment logic is the same, which will not be described here.

[0089] By injecting different voltages through the signal source Us, the voltage values across the sampling units r1 and r2 can be accurately collected, and the impedance of any one of the power transmission lines DC+ and DC- to the ground can be accurately calculated.

[0090] The signal source Us in the above embodiments can use a square wave signal generator to output a square wave signal with a certain frequency and amplitude. The amplitude of the square wave signal can be less than or equal to 36V, for example, a square wave signal of ±24V can be output.

[0091] Further, the insulation detection device provided by the embodiments of the present application can also detect the voltage outside the gun wire, i.e., the voltage outside the power switches K1 and K2, to meet the application requirements of some scenarios.

[0092] Specifically, the auxiliary switch S1 is not closed, the signal source Us does not inject voltage, the voltage across the first sampling unit r1 is Ur5, the voltage across the second sampling resistor r2 is Ur6, and the voltage outside the gun wire U K1K2 The calculation formula of the voltage outside the gun wire U

[0093] The insulation detection device provided by the embodiment of the present application can ensure that high-precision signal acquisition is realized and the precision of insulation detection is improved in the case that the impedance of the power transmission line to the ground is unbalanced.

[0094] Correspondingly, the embodiment of the present application further provides a charging pile, as shown in FIG. 5, the charging pile 400 comprises the above-mentioned insulation detection device 100.

[0095] By using the charging pile, real-time and high-precision insulation detection of the power supply circuit can be realized in charging the electric vehicle, and the bridge arm resistor (i.e. the voltage dividing resistor R1 and R2 in FIG. 1 and FIG. 2) in the insulation detection device 100 can be greater than or equal to 500kΩ, so that the insulation detection of the vehicle end is not affected.

[0096] The insulation detection device provided by the embodiment of the present application can be not only used in the above-mentioned charging pile, but also applied to any equipment or product requiring DC side insulation detection.

[0097] Correspondingly, the embodiment of the present application further provides an insulation detection method for a power supply circuit, as shown in FIG. 1, the power supply circuit is provided with a first sampling unit r1 and a second sampling unit r2, and a signal source Us and a reference source Uref are mirror-connected between a power supply ground PE and the first sampling unit r1 and the second sampling unit r2.

[0098] As shown in FIG. 5, it is a flow chart of the insulation detection method provided by the embodiment of the present application.

[0099] In step 501, when performing insulation detection, the signal source injects voltage to the power supply ground of the power supply circuit.

[0100] The voltage can be a square wave signal of a certain frequency.

[0101] In step 502, the first sampling voltage U1 and the corresponding first amplification voltage U2 on the first sampling unit are obtained, and the second sampling voltage U3 and the corresponding second amplification voltage U4 on the second sampling unit are obtained.

[0102] At step 503, a first voltage is determined according to the first sampling voltage U1 and the corresponding first amplification voltage U2 on the first sampling unit, a second voltage is determined according to the second sampling voltage U3 and the corresponding second amplification voltage U4 on the second sampling unit, and the insulation of the power supply loop is determined according to the first voltage and the second voltage.

[0103] Specifically, the ground resistance across the power supply loop can be calculated according to the first voltage and the second voltage, and the insulation of the power supply loop can be determined according to the ground resistance across the power supply loop. The specific calculation process and the determination of the insulation can be referred to the description in the foregoing embodiment of the insulation detection device, which will not be repeated here.

[0104] The insulation detection method provided by the embodiment of the present application can determine the voltage value across the sampling unit by collecting the sampling voltage and the amplification voltage on the first sampling unit and the second sampling unit respectively, determine the voltage signal strength across the sampling unit according to the voltage value, and then determine the high-precision sampling voltage by using appropriate sampling precision, accurately calculate the impedance of the power transmission line to the ground, and determine the insulation of the power supply loop. By using the present application, high-precision signal collection can be realized even in the case of imbalance of the impedance of the power transmission line to the ground, thereby improving the precision of the insulation detection.

[0105] Moreover, in the insulation detection method provided by the embodiment of the present application, the insulation detection is performed by injecting voltage into the power supply ground line of the power supply loop by the signal source, and the high-precision voltage of the first sampling unit and the second sampling unit can be obtained at the same time by one-time voltage injection, so that the insulation detection process can be realized simply and efficiently.

[0106] The "connection" appearing in the embodiment of the present application refers to various connection modes such as direct connection or indirect connection, so as to realize the communication between devices, and the present application does not make any limitation thereto.

[0107] It should be understood that in various embodiments of the present application, the size of the serial number of the above processes does not mean the order of execution, and the execution order of the processes should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0108] The above-described embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, the above-described embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present application are wholly or partially generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center through a wired or wireless manner.

[0109] In several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the above-described device embodiments are only illustrative; for example, the division of the units is only a logical function division, and actual implementation can have another division manner; for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0110] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0111] The integrated units implemented in the form of software functional units described above can be stored in a computer-readable storage medium. The software functional units described above are stored in a storage medium, including a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute part of the steps of the methods described in the embodiments of the present application.

[0112] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can make various modifications and changes without departing from the spirit and scope of the present application, therefore the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. An insulation detection device characterized by comprising: 1) an insulation detection unit that detects insulation of a power line, The application relates to an insulation detection device and a method thereof. The device comprises a first sampling unit and a second sampling unit arranged on a power supply circuit, a first signal processing module, a second signal processing module, a detection module, a signal source and a reference source; a negative terminal of the signal source and a negative terminal of the reference source are connected to a signal ground, a positive terminal of the signal source is connected to a power supply ground, and a positive terminal of the reference source is connected to the first sampling unit and the second sampling unit respectively; the signal source is used for injecting a voltage into the power supply ground; the reference source is used for outputting a fixed voltage; the first signal processing module is used for acquiring a first sampling voltage U1 on the first sampling unit and a corresponding first amplified voltage U2; the second signal processing module is used for acquiring a second sampling voltage U3 on the second sampling unit and a corresponding second amplified voltage U4; the detection module is used for determining a first voltage from the first sampling voltage U1 on the first sampling unit and the corresponding first amplified voltage U2 and determining a second voltage from the second sampling voltage U3 on the second sampling unit and the corresponding second amplified voltage U4, and determining the insulation of the power supply circuit according to the first voltage and the second voltage.

2. The device according to claim 1, wherein: the first signal processing module comprises: a first voltage acquisition unit, which is used for acquiring the first sampling voltage U1 on the first sampling unit and outputting the first sampling voltage U1 to the detection module; a first voltage amplification unit, which is used for amplifying the first sampling voltage U1 and outputting a first amplified voltage U2 to the detection module; the second signal processing module comprises: a second voltage acquisition unit, which is used for acquiring the second sampling voltage U3 on the second sampling unit and outputting the second sampling voltage U3 to the detection module; a second voltage amplification unit, which is used for amplifying the second sampling voltage U3 and outputting a second amplified voltage U4 to the detection module.

3. The insulation detection device according to claim 2, characterized in that, The first voltage acquisition unit and the second voltage acquisition unit are voltage followers.

4. The insulation detection device according to claim 2, characterized by The first voltage amplification unit and the second voltage amplification unit are operational amplifiers.

5. The device according to claim 2, wherein: the detection module is used for calculating a ground resistance between two ends of the power supply circuit according to the first voltage and the second voltage, and determining the insulation of the power supply circuit according to the ground resistance between the two ends of the power supply circuit.

6. The insulation detection device of claim 1, wherein The resistance values of the first sampling unit and the second sampling unit are equal.

7. The insulation detection device according to any one of claims 1 to 6, characterized in that The output voltage of the reference source is 0-5V.

8. The insulation detection device according to any one of claims 1 to 6, characterized in that The signal source outputs a square wave signal.

9. A charging station, characterized in that The device comprises the insulation detection device according to any one of claims 1 to 8.

10. An insulation detection method characterized by comprising: The method is used for a power supply circuit, and the power supply circuit is provided with a first sampling unit and a second sampling unit and a signal source and a reference source which are mirror-connected between a power supply ground and the first sampling unit and the second sampling unit; the method comprises: when insulation detection is performed, a voltage is injected into the power supply ground of the power supply circuit by the signal source. acquire a first sampling voltage U1 and a corresponding first amplification voltage U2 on the first sampling unit, and acquire a second sampling voltage U3 and a corresponding second amplification voltage U4 on the second sampling unit; determine a first voltage according to the first sampling voltage U1 and the corresponding first amplification voltage U2 on the first sampling unit, determine a second voltage according to the second sampling voltage U3 and the corresponding second amplification voltage U4 on the second sampling unit, and determine the insulation of the power supply loop according to the first voltage and the second voltage.

11. The insulation detection method according to claim 10, wherein The determination of the insulation of the power supply loop according to the first voltage and the second voltage comprises: According to the first voltage and the second voltage, the resistance to ground between the two ends of the power supply loop is calculated; determine the insulation of the power supply loop according to the resistance to ground between the two ends of the power supply loop.

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