A loop ground detection method and a loop ground detection device

Abstract

The embodiment of the present application discloses a loop grounding detection method and a loop grounding detection device, wherein the loop grounding detection device comprises a control module, a digital grounding plate and a loop card. The relay on the digital grounding plate is used to ground the loop card, and the control module is used to control the on-off of the relay at a preset frequency, so that the loop positive line and the loop negative line on the loop card are connected to the digital ground and disconnected at a corresponding frequency. The loop card detects the state and the current change after the loop positive line and the loop negative line are connected to the digital ground each time, to determine whether the loop positive line and the loop negative line have a grounding fault. The embodiment of the present application can quickly locate the line with the grounding fault, and solves the technical problem that the line with the grounding fault cannot be quickly located in the prior art.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the field of electric power, in particular to a loop grounding detection method and a loop grounding detection device. BACKGROUND

[0002] At present, with the development of science and technology, all aspects of people's life have been inseparable from electric power. In order to enable people to use electric power in every corner of the residence and workplace, the electric wire needs to be arranged in various places of the building. However, since the electric wire and other lines are usually arranged in the same pipeline, the wire skin is inevitably damaged or the connection is in contact with the pipeline (the pipeline is generally connected to the ground), so that the grounding fault occurs, and it is difficult to quickly locate the line with the grounding fault in the prior art.

[0003] In summary, how to quickly locate the line with the grounding fault has become a technical problem to be solved at present. SUMMARY

[0004] The embodiment of the present application provides a loop grounding detection method and a loop grounding detection device, and solves the technical problem that the prior art cannot quickly locate the line with the grounding fault.

[0005] In a first aspect, the embodiment of the present application provides a loop grounding detection method, the method is applicable to a loop grounding detection device, the loop grounding detection device comprises a control module, a digital grounding plate and a loop card, the control module and the loop card are arranged on the digital grounding plate, a relay is arranged on the digital grounding plate, a first end of the loop card is connected with a first end of a loop positive line, a second end of the loop card is connected with a first end of a loop negative line, a second end of the loop positive line and a second end of the loop negative line are connected with a load to form a loop, a digital grounding end of the loop card is connected with a first end of the relay, a second end of the relay is connected with a digital ground, an output end of the control module is connected with a control end of the relay, and the control module is used for controlling on-off of the relay, and the method comprises the following steps:

[0006] The control module controls the relay to be turned on and turned off at a preset frequency;

[0007] The loop card detects a state of the loop positive line and detects a current of the loop negative line in each process that the relay is turned on and turned off;

[0008] The loop card determines whether the loop positive line has a grounding fault according to the state of the loop positive line, and determines whether the loop negative line has a grounding fault according to the current of the loop negative line.

[0009] Preferably, the loop card determines whether the positive line of the loop has a ground fault according to the state of the positive line of the loop, and determines whether the negative line of the loop has a ground fault according to the current of the negative line of the loop, comprising:

[0010] The loop card determines whether the positive line of the loop is in a short-circuit state during each process of turning on and turning off of the relay, and if yes, determines that the positive line of the loop has a ground fault.

[0011] The loop card determines whether the current of the negative line of the loop decreases during each process of turning on and turning off of the relay, and if yes, determines that the negative line of the loop has a ground fault.

[0012] Preferably, a self-restoring fuse device is arranged on the positive line of the loop, a first end of the self-restoring fuse device is connected with a first end of the loop card, and a second end of the self-restoring fuse device is connected with the load.

[0013] Correspondingly, the loop card determines whether the positive line of the loop has a ground fault according to the state of the positive line of the loop, comprising:

[0014] The loop card determines whether the positive line of the loop is in a self-restoring fuse protection state during each process of turning on and turning off of the relay, and if yes, determines that the positive line of the loop has a ground fault, the self-restoring fuse protection state is caused by the self-restoring fuse device when the positive line of the loop has a short circuit.

[0015] In a second aspect, an embodiment of the present application provides a loop ground detection device, comprising a control module, a digital ground plate and a loop card, the control module and the loop card are arranged on the digital ground plate, a relay is arranged on the digital ground plate, a first end of the loop card is connected with a first end of a positive line of a loop, a second end of the loop card is connected with a first end of a negative line of the loop, a second end of the positive line of the loop and a second end of the negative line of the loop are connected with a load to form a loop, a digital ground end of the loop card is connected with a first end of the relay, a second end of the relay is connected with a digital ground, an output end of the control module is connected with a control end of the relay, and the control module is used for controlling on-off of the relay.

[0016] The control module is used for periodically controlling the relay to turn on and turn off.

[0017] The loop card is used for detecting the state of the positive line of the loop and detecting the current of the negative line of the loop during each process of turning on and turning off of the relay.

[0018] The loop card is used to determine whether the loop positive line has a ground fault according to the loop positive line and whether the loop negative line has a ground fault according to the current of the loop negative line.

[0019] Preferably, a self-restoring fuse is arranged on the loop positive line, a first end of the self-restoring fuse is connected with the first end of the loop card, and a second end of the self-restoring fuse is connected with the load.

[0020] Preferably, the self-restoring fuse is a self-restoring fuse.

[0021] Preferably, a first Schottky diode is further arranged on the loop positive line, an anode of the first Schottky diode is connected with the first end of the loop card, and a cathode of the first Schottky diode is connected with the first end of the self-restoring fuse.

[0022] Preferably, a current sampling circuit is arranged on the loop negative line, a first end of the current sampling circuit is connected with the second end of the loop card, and a second end of the current sampling circuit is connected with the load.

[0023] Preferably, the current sampling circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, an amplifier and a first capacitor.

[0024] The first end of the first resistor and the first end of the second resistor are both connected with the second end of the loop card, the second end of the first resistor is grounded, the second end of the second resistor is connected with an output end of the amplifier, a first end of the first capacitor and a first end of the third resistor, an inverting input end of the amplifier is connected with a second end of the first capacitor, a second end of the third resistor and a first end of the fifth resistor, a non-inverting input end of the amplifier is connected with a first end of the fourth resistor, a second end of the fourth resistor and a second end of the fifth resistor are respectively connected with a first end of the sixth resistor and a second end of the sixth resistor, and the first end of the sixth resistor is further connected with the load.

[0025] Preferably, a second Schottky diode is further arranged on the loop negative line, an anode of the second Schottky diode is connected with the load, and a cathode of the second Schottky diode is connected with the second end of the current sampling circuit.

[0026] The embodiment of the present application grounds the loop card through the relay on the digital ground plate, and controls the on-off of the relay at a preset frequency through the control module, so that the loop positive line and the loop negative line on the loop card are connected to the digital ground at a corresponding frequency and then disconnected, and the loop card determines whether the loop positive line and the loop negative line have a grounding fault by detecting the state and the current change of the loop positive line and the loop negative line after being connected to the digital ground each time. The embodiment of the present application can quickly locate the line with a grounding fault, and solves the technical problem that the line with a grounding fault cannot be quickly located in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A flow chart of a loop grounding detection method provided by the embodiment of the present application.

[0028] Figure 2 A structure schematic diagram of a loop grounding detection device provided by the embodiment of the present application.

[0029] Figure 3 A schematic diagram of a loop positive line with a grounding fault provided by the embodiment of the present application.

[0030] Figure 4 A schematic diagram of a loop negative line with a grounding fault provided by the embodiment of the present application.

[0031] Figure 5 A structure schematic diagram of another loop grounding detection device provided by the embodiment of the present application.

[0032] Figure 6 A structure schematic diagram of another loop grounding detection device provided by the embodiment of the present application.

[0033] Figure 7 A structure schematic diagram of a control module provided by the embodiment of the present application

[0034] REFERENCE NUMERALS

[0035] Control module 1, digital ground plate 2, loop card 3, loop positive line 31, loop negative line 32, load 4, relay K, first Schottky diode D1, first Schottky diode D2, self-restoring fuse F1, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5, sixth resistor R6, amplifier U1, first capacitor C1, processor 5. DETAILED DESCRIPTION

[0036] The following description and drawings are illustrative of specific embodiments of the application and are not intended to be limiting thereof. The embodiments are presented by way of example only. Separate components and functions are optional, and the order of operations can vary. Parts and features of some embodiments can be included or replaced by parts and features of other embodiments. The scope of the embodiments of the application encompasses the entire scope of the claims and all available equivalents of the claims. In this document, the terms "the application," "one embodiment," "an embodiment," and "the only embodiment" mean an example of the things being described, not a requirement that the described item be the only way to implement the thing. In this document, the term "for example," by itself, allows for anything to be needed. Only where in the foregoing Application Description specifically restricted, are aspects, features, products, etc. not to be implemented. In this document, the term "or" by itself is not to be interpreted as an "exclusive or" unless it is specifically indicated otherwise. In addition, the terms "comprise," "comprising," "include," "including," and "includes" are not used solely to be had specific reference to the various features, elements and / or components that a process, method, product or apparatus comprises, includes or has. In this document, the terms "coupled," "coupling," and "connect" are used broadly and encompass both direct and indirect connections, as well as passive and active coupling. The terms "coupled" and "connecting" are not restricted to direct or physical connections. In this document, the term "associated with" is used to mean that one entity is associated with another, not necessarily in a causal relationship. In this document, the term "determining" is used to mean obtaining, calculating, predicting, and / or ascertaining. In this document, the term "application" is used to mean a computer-related performance of a specific function via computer software. In this document, the term "if" by itself is not to be interpreted as an "exclusive if" unless specifically indicated otherwise. In addition, the terms "another" and "one" are not used to mean "only one" unless specifically indicated otherwise.

[0037] As Figure 1 shown, Figure 1 a flow chart of a loop ground detection method provided by an embodiment of the application. The loop ground detection method provided by the embodiment of the application is applicable to a loop ground detection device. The loop ground detection device comprises a control module 1, a digital ground plate 2, and a loop card 3. The control module 1 and the loop card 3 are arranged on the digital ground plate 2. A relay K is arranged on the digital ground plate 2. A digital ground end of the loop card 3 is connected with a first end of the relay K. A second end of the relay K is connected with a digital ground. An output end of the control module 1 is connected with a control end of the relay K, for controlling on-off of the relay K. A first end of the loop card 3 is connected with a first end of a loop positive line 31. A second end of the loop card 3 is connected with a first end of a loop negative line 32. A second end of the loop positive line 31 and a second end of the loop negative line 32 are connected with a load 4 to form a loop.

[0038] As Figure 2 shown, Figure 2A structure diagram of a loop ground detection device provided by the embodiment of the present application comprises a control module 1, a digital ground plate 2 and a loop card 3, the first end of the loop card 3 is connected with the first end of a loop positive line 31, the second end of the loop card 3 is connected with the first end of a loop negative line 32, the second end of the loop positive line 31 and the second end of the loop negative line 32 are connected with a load 4 to form a loop. The control module 1 and the loop card 3 are both arranged on the digital ground plate 2, wherein the digital ground plate 2 is used to connect the loop card 3 to a digital ground. Specifically, a relay K is arranged on the digital ground plate 2, the digital ground end of the loop card 3 is connected with the first end of the relay K, the second end of the relay K is connected with the digital ground, and the output end of the control module 1 is connected with the control end of the relay K, under the control of the control module 1, the relay K can be turned on and turned off. It can be understood that the digital ground end of the loop positive line 31 and the digital ground end of the loop negative line 32 are both grounded through the digital ground end of the loop card 3, when the control module 1 controls the relay K to be turned on, the digital ground plate 2 will connect the loop card 3 to the digital ground, and the loop positive line 31 and the loop negative line 32 will also be connected to the digital ground at the same time; and after the control module 1 controls the relay K to be turned off, the digital ground plate 2 disconnects the loop card 3 from the digital ground, and the loop positive line 31 and the loop negative line 32 will also be disconnected from the digital ground at the same time.

[0039] The loop ground detection method provided by the embodiment of the present application comprises:

[0040] Step 101, the control module controls the relay to be turned on and turned off at a preset frequency.

[0041] In the embodiment, when the loop ground fault detection is performed, the control module 1 controls the relay K to be turned on and turned off at a preset frequency, so that the loop positive line 31 and the loop negative line 32 of the loop card 3 are connected to the digital ground and then disconnected at a certain frequency. It can be understood that the frequency of the relay action can be set according to actual needs, and the number of times that the control module 1 controls the relay K to be turned on and turned off can also be set in advance, for example, the number of times that the relay K is turned on and turned off can be set to 5 times, etc., that is, the loop card 3 is connected to the digital ground for 5 times.

[0042] Step 102, the loop card detects the state of the loop positive line and the current of the loop negative line in the process of each time that the relay is turned on and turned off.

[0043] The loop card 3 detects the state of the loop positive line 31 and the current on the loop negative line 32 in the process of each time that the relay K is turned on and turned off, that is, each time that the loop card 3 is connected to the digital ground, so as to subsequently judge whether the loop positive line 31 and the loop negative line 32 exist a ground fault according to the state of the loop positive line 31 and the current of the loop negative line 32.

[0044] Step 103, the loop card determines whether the loop positive line has a ground fault according to the state of the loop positive line, and determines whether the loop negative line has a ground fault according to the current of the loop negative line.

[0045] Finally, the loop card 3 can determine whether the loop positive line 31 has a ground fault according to the state of the loop positive line 31 each time after being connected to the digital ground, and determine whether the loop negative line 32 has a ground fault according to the current of the loop negative line 32 each time after being connected to the digital ground. Specifically, when the loop positive line 31 and the loop negative line 32 do not have a ground fault, the closing and opening of the relay K will not affect the loop positive line 31 and the loop negative line 32, the state of the loop positive line 31 is a normal communication state, and the current of the loop negative line 32 is also a normal value and does not change. When the loop positive line 31 has a ground fault and the loop negative line 32 has a ground fault, the ground point and the digital ground are connected to each other when the loop positive line 31 and the loop negative line 32 are connected to the digital ground, so that the state of the loop positive line 31 and the current of the loop negative line 32 change. Therefore, whether the loop positive line 31 and the loop negative line 32 have a ground fault can be determined according to the state of the loop positive line 31 and the current of the loop negative line 32 each time when the loop card 3 is connected to the digital ground.

[0046] In the above embodiment, the loop card determines whether the loop positive line has a ground fault according to the state of the loop positive line, and determines whether the loop negative line has a ground fault according to the current of the loop negative line in step 103, comprising:

[0047] Step 1031, the loop card determines whether the loop positive line is in a short circuit state during each time when the relay is turned on and turned off according to the state of the loop positive line, and determines that the loop positive line has a ground fault if yes.

[0048] In this embodiment, when the loop positive line 31 has a ground fault, the impedance between the loop positive line 31 and the ground is infinite, so the loop positive line 31 is not short-circuited with the ground. However, when the loop positive line 31 is connected to the digital ground, the loop positive line 31 is equivalent to being short-circuited with the ground, the current of the loop positive line 31 increases, and the loop positive line 31 is in a short circuit state, as shown in FIG. 5. When the digital ground of the loop positive line 31 is disconnected, the current of the loop positive line 31 returns to normal. Therefore, whether the loop positive line 31 has a ground fault can be determined by detecting whether the loop positive line 31 is in a short circuit state during each time when the relay K is turned on and turned off. Figure 3

[0049] Step 1032, the loop card determines whether the current of the loop negative line decreases during each time when the relay is turned on and turned off according to the current of the loop negative line, and determines that the loop negative line has a ground fault if yes.

[0050] ​When a ground fault occurs in the circuit negative line 32, the ground point of the circuit negative line 32 is connected to the digital ground through the relay K after the circuit negative line 32 is connected to the digital ground, and a part of the current of the circuit negative line 32 flows into the digital ground through the relay K, so that the current on the circuit negative line 32 is reduced to 0, as shown in FIG. 8. When the circuit negative line 32 is disconnected from the digital ground, the current of the circuit negative line 32 returns to the normal level, so that whether a ground fault occurs in the circuit negative line 32 can be determined by detecting whether the current of the circuit negative line 32 is reduced each time the relay K is turned on and turned off. Figure 4

[0051] In another embodiment, the circuit ground detection device provided by the embodiment of the present application also includes a control module 1, a digital ground plate 2, and a circuit card 3. The control module 1 and the circuit card 3 are arranged on the digital ground plate 2. The control module 1 and the circuit card 3 are arranged on the digital ground plate 2. The digital ground plate 2 is provided with a relay K. A first end of the circuit card 3 is connected to a first end of a circuit positive line 31. A second end of the circuit card 3 is connected to a first end of a circuit negative line 32. A second end of the circuit positive line 31 and a second end of the circuit negative line 32 are connected to a load 4 to form a circuit. A digital ground end of the circuit card 3 is connected to a first end of the relay K. A second end of the relay K is connected to a digital ground. An output end of the control module 1 is connected to a control end of the relay K, so as to control the on-off of the relay K.

[0052] The control module 1 is used to periodically control the relay K to be turned on and turned off.

[0053] The circuit card 3 is used to detect the state of the circuit positive line 31 and the current of the circuit negative line 32 each time the relay K is turned on and turned off.

[0054] The circuit card 3 is used to determine whether a ground fault occurs in the circuit positive line 31 according to the circuit positive line 31, and determine whether a ground fault occurs in the circuit negative line 32 according to the current of the circuit negative line 32.

[0055] In the above, the embodiment of the present application connects the circuit card to the digital ground through the relay on the digital ground plate, and controls the on-off of the relay by the control module at a preset frequency, so that the circuit positive line and the circuit negative line on the circuit card are connected to the digital ground and then disconnected at a corresponding frequency. The circuit card determines whether a ground fault occurs in the circuit positive line and the circuit negative line by detecting the state and the change of the current of the circuit positive line and the circuit negative line after being connected to the digital ground each time. The embodiment of the present application can quickly locate the line with a ground fault, and solves the technical problem that the line with a ground fault cannot be quickly located in the prior art.

[0056] ​On the basis of the above-mentioned embodiment, the circuit positive line 31 is provided with a self-restoring fuse device F1, the first end of the self-restoring fuse device F1 is connected with the first end of the circuit card 3, and the second end of the self-restoring fuse device F1 is connected with the load 4.

[0057] In one embodiment, in order to protect the load 4 connected on the circuit positive line 31, the circuit positive line 31 is further provided with a self-restoring fuse device F1, as shown in the figure. The self-restoring fuse device F1 has the functions of overcurrent and overheating protection and automatic recovery, and can provide overcurrent protection for the circuit positive line 31 and does not need to be frequently replaced. In this embodiment, the first end of the self-restoring fuse device F1 is connected with the first end of the circuit card 3, and the second end of the self-restoring fuse device F1 is connected with the load 4. Figure 5

[0058] Correspondingly, the circuit card determines whether the circuit positive line has a ground fault according to the state of the circuit positive line, including:

[0059] The circuit card determines whether the circuit positive line is in a self-restoring fuse protection state during each process of turning on and turning off the relay according to the state of the circuit positive line, and if yes, it is determined that the circuit positive line has a ground fault, and the self-restoring fuse protection state is caused by the action of the self-restoring fuse device when a short circuit occurs in the circuit positive line.

[0060] If the self-restoring fuse device F1 is provided in the circuit positive line 31, after a short circuit occurs in the circuit positive line 31 after being connected to the digital ground, the self-restoring fuse device F1 will act, so that the circuit positive line 31 enters the self-restoring fuse protection state. At this time, the circuit card 3 can detect whether the circuit positive line 31 is in the self-restoring fuse protection state when detecting the state of the circuit positive line 31 each time it is connected to the digital ground, and if yes, it means that the circuit positive line 31 has a short circuit leading to the action of the self-restoring fuse device F1. Therefore, by judging whether the circuit positive line 31 is in the self-restoring fuse protection state during each process of turning on and turning off the relay K, it can be determined whether the circuit positive line 31 has a ground fault.

[0061] On the basis of the above-mentioned embodiment, the self-restoring fuse device F1 is a self-restoring fuse.

[0062] ​In one embodiment, the self-restoring fuse F1 is a self-restoring fuse, which is composed of a specially treated polymer and conductive particles (carbon black) distributed therein. Under normal operation, the polymer tightly binds the conductive particles outside the crystalline structure to form a chain-shaped conductive path. At this time, the self-restoring fuse is in a low-resistance state, and the heat generated by the current flowing through the self-restoring fuse is small, which does not change the crystal structure. When a short circuit or overload occurs in the circuit, the large current flowing through the self-restoring fuse generates heat, which causes the polymer to melt and rapidly expand in volume, forming a high-resistance state, and the working current rapidly decreases, thereby limiting and protecting the circuit. When the fault is eliminated, the self-restoring fuse re-cools and crystallizes, the volume shrinks, the conductive particles re-form a conductive path, and the self-restoring fuse returns to a low-resistance state, thereby completing the protection of the circuit without the need for manual replacement.

[0063] On the basis of the above embodiment, the circuit positive line 31 is further provided with a first Schottky diode D1, the anode of the first Schottky diode D1 is connected with the first end of the circuit card 3, and the cathode of the first Schottky diode D1 is connected with the first end of the self-restoring fuse F1.

[0064] In one embodiment, as shown in the figure, Figure 5 the circuit positive line 31 is further provided with a first Schottky diode D1, the anode of the first Schottky diode D1 is connected with the first end of the circuit card 3, and the cathode of the first Schottky diode D1 is connected with the first end of the self-restoring fuse F1. By setting the first Schottky diode D1, the circuit positive line 31 and other lines can be isolated, thereby avoiding mutual influence of the grounded circuits.

[0065] On the basis of the above embodiment, the circuit negative line 32 is provided with a current sampling circuit, the first end of the current sampling circuit is connected with the second end of the circuit card 3, and the second end of the current sampling circuit is connected with the load 4.

[0066] In one embodiment, as shown in the figure, Figure 5 the circuit negative line 32 is further provided with a current sampling circuit, the first end of the current sampling circuit is connected with the second end of the circuit card 3, and the second end of the current sampling circuit is connected with the load 4. The current sampling circuit is used to collect the current on the circuit negative line 32, so that the circuit card 3 detects the current on the circuit negative line 32 through the current sampling circuit.

[0067] On the basis of the above embodiment, the current sampling circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, an amplifier U1, and a first capacitor C1.

[0068] The first end of the first resistor R1 and the first end of the second resistor R2 are connected to the second end of the loop card 3, the second end of the first resistor R1 is grounded, the second end of the second resistor R2 is connected to the output end of the amplifier U1, the first end of the first capacitor C1 and the first end of the third resistor R3, the inverting input end of the amplifier U1 is connected to the second end of the first capacitor C1, the second end of the third resistor R3 and the first end of the fifth resistor R5, the non-inverting input end of the amplifier U1 is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the second end of the fifth resistor R5, the first end of the sixth resistor R6 and the second end of the sixth resistor R6, and the first end of the sixth resistor R6 is also connected to the load 4.

[0069] In one embodiment, as shown in Figure 6 the current sampling circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, an amplifier U1 and a first capacitor C1. Among them, the first end of the first resistor R1 and the first end of the second resistor R2 are connected to the second end of the loop card 3, the second end of the first resistor R1 is grounded, the second end of the second resistor R2 is connected to the output end of the amplifier U1, the first end of the first capacitor C1 and the first end of the third resistor R3, the inverting input end of the amplifier U1 is connected to the second end of the first capacitor C1, the second end of the third resistor R3 and the first end of the fifth resistor R5, the non-inverting input end of the amplifier U1 is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the second end of the fifth resistor R5, the first end of the sixth resistor R6 and the second end of the sixth resistor R6, and the first end of the sixth resistor R6 is also connected to the load 4. The fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are sampling resistors, the first capacitor C1 and the third resistor R3 constitute a feedback loop of the amplifier U1, and the fourth resistor R4 and the fifth resistor R5 input the current between the sixth resistor R6 to the amplifier U1 for amplification, and then flow through the first resistor R1 and the second resistor R2 into the second end of the loop card 3. The model of the amplifier U1 is LM358LV.

[0070] On the basis of the above embodiment, the second Schottky diode D2 is also provided on the loop negative line 32, the anode of the second Schottky diode D2 is connected to the load 4, and the cathode of the second Schottky diode D2 is connected to the second end of the current sampling circuit.

[0071] In one embodiment, as shown in Figure 6As shown, the second Schottky diode D2 is also arranged on the loop negative line 32, the anode of the second Schottky diode D2 is connected with the load 4, and the cathode of the second Schottky diode D2 is connected with the second end of the current sampling circuit, by arranging the second Schottky diode D2, the loop negative line 32 and other lines can be isolated, so as to avoid mutual influence of the grounding loop.

[0072] In addition, in another embodiment, the control module comprises a processor and a relay control circuit, such as Figure 7 As shown, the processor 5 is connected with the relay control circuit through the relay control pin, the processor 5 controls the relay K to act through the 5th pin, the 6th pin and the 7th pin of the relay K, when the 6th pin and the 7th pin are connected, the relay K is disconnected, and when the processor 5 controls the 5th pin and the 6th pin to be connected, the relay K is closed.

[0073] In the above, the embodiment of the present application grounds the loop card through the relay on the digital grounding plate, and controls the relay to be on and off at a preset frequency by using the control module, so that the loop positive line and the loop negative line on the loop card are connected to the digital ground at a corresponding frequency and then disconnected, the loop card determines whether the loop positive line and the loop negative line exist a grounding fault by detecting the state and the current change of the loop positive line and the loop negative line after being connected to the digital ground each time. The embodiment of the present application can quickly locate the line with a grounding fault, and solves the technical problem that the line with a grounding fault cannot be quickly located in the prior art.

[0074] Note that the above is only the preferred embodiment of the present application and the technical principle applied. Those skilled in the art will understand that the embodiment of the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, re-adjustments and substitutions without departing from the protection scope of the embodiment of the present application. Therefore, although the embodiment of the present application has been described in more detail through the above embodiments, the embodiment of the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the embodiment of the present application, and the scope of the embodiment of the present application is determined by the scope of the appended claims.

Claims

1. A loop ground detection method, characterized by, The method is suitable for a loop ground detection device, the loop ground detection device comprises a control module, a digital ground plate and a loop card, the control module and the loop card are arranged on the digital ground plate, a relay is arranged on the digital ground plate, a first end of the loop card is connected with a first end of a loop positive line, a second end of the loop card is connected with a first end of a loop negative line, a second end of the loop positive line and a second end of the loop negative line are connected with a load to form a loop, a digital ground end of the loop card is connected with a first end of the relay, a second end of the relay is connected with a digital ground, an output end of the control module is connected with a control end of the relay, and the control module is used for controlling on-off of the relay, and the method comprises the following steps: The control module controls the relay to be turned on and turned off at a preset frequency; In each process of turning on and turning off of the relay, the loop card detects a state of the loop positive line and detects a current of the loop negative line; The loop card determines whether the loop positive line has a ground fault according to the state of the loop positive line, and determines whether the loop negative line has a ground fault according to the current of the loop negative line.

2. The method of claim 1, wherein, The loop card determines whether the loop positive line has a ground fault according to the state of the loop positive line, and determines whether the loop negative line has a ground fault according to the current of the loop negative line, and the method comprises the following steps: The loop card determines whether the loop positive line is in a short circuit state in each process of turning on and turning off of the relay according to the state of the loop positive line, and if yes, it is determined that the loop positive line has a ground fault; The loop card determines whether the current of the loop negative line decreases in each process of turning on and turning off of the relay according to the current of the loop negative line, and if yes, it is determined that the loop negative line has a ground fault.

3. The method of claim 1, wherein, A self-restoring fuse device is arranged on the loop positive line, a first end of the self-restoring fuse device is connected with the first end of the loop card, and a second end of the self-restoring fuse device is connected with the load; Correspondingly, the loop card determines whether the loop positive line has a ground fault according to the state of the loop positive line, and the method comprises the following steps: The loop card determines whether the loop positive line is in a self-restoring fuse protection state in each process of turning on and turning off of the relay according to the state of the loop positive line, and if yes, it is determined that the loop positive line has a ground fault, and the self-restoring fuse protection state is caused by action of the self-restoring fuse device when the loop positive line has a short circuit.

4. A loop ground detection device, characterized by, The application relates to a circuit card, a control module and a digital ground plate, wherein the control module and the circuit card are arranged on the digital ground plate, a relay is arranged on the digital ground plate, a first end of the circuit card is connected with a first end of a positive line of a circuit, a second end of the circuit card is connected with a first end of a negative line of the circuit, a second end of the positive line of the circuit and a second end of the negative line of the circuit are connected with a load to form the circuit, a digital ground end of the circuit card is connected with a first end of the relay, a second end of the relay is connected with a digital ground, an output end of the control module is connected with a control end of the relay, and the control module is used for controlling on-off of the relay. The control module is used for periodically controlling on-off of the relay. The circuit card is used for detecting a state of the positive line of the circuit and detecting a current of the negative line of the circuit during each on-off process of the relay. The circuit card is used for determining whether the positive line of the circuit has a ground fault according to the positive line of the circuit and determining whether the negative line of the circuit has a ground fault according to the current of the negative line of the circuit.

5. A loop ground detection device according to claim 4, wherein A self-recovery fuse device is arranged on the positive line of the circuit, a first end of the self-recovery fuse device is connected with the first end of the circuit card, and a second end of the self-recovery fuse device is connected with the load.

6. A loop ground detection device according to claim 5, wherein The self-recovery fuse device is a self-recovery fuse.

7. A loop ground detection device according to claim 5, wherein A first Schottky diode is further arranged on the positive line of the circuit, an anode of the first Schottky diode is connected with the first end of the circuit card, and a cathode of the first Schottky diode is connected with the first end of the self-recovery fuse device.

8. The loop grounding detection apparatus of claim 4, wherein A current sampling circuit is arranged on the negative line of the circuit, a first end of the current sampling circuit is connected with the second end of the circuit card, and a second end of the current sampling circuit is connected with the load.

9. A loop ground detection device according to claim 7, wherein The current sampling circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, an amplifier and a first capacitor. A first end of the first resistor and a first end of the second resistor are both connected with the second end of the circuit card, a second end of the first resistor is grounded, a second end of the second resistor is connected with an output end of the amplifier, a first end of the first capacitor and a first end of the third resistor, an inverting input end of the amplifier is connected with a second end of the first capacitor, a second end of the third resistor and a first end of the fifth resistor, a non-inverting input end of the amplifier is connected with a first end of the fourth resistor, a second end of the fourth resistor and a second end of the fifth resistor are respectively connected with a first end of the sixth resistor and a second end of the sixth resistor, and the first end of the sixth resistor is further connected with the load.

10. A loop ground detection device according to claim 8, wherein A second Schottky diode is further arranged on the negative line of the circuit, an anode of the second Schottky diode is connected with the load, and a cathode of the second Schottky diode is connected with the second end of the current sampling circuit.

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