CN220605548U - Electric shock protection device - Google Patents
Electric shock protection device Download PDFInfo
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- CN220605548U CN220605548U CN202321831247.9U CN202321831247U CN220605548U CN 220605548 U CN220605548 U CN 220605548U CN 202321831247 U CN202321831247 U CN 202321831247U CN 220605548 U CN220605548 U CN 220605548U
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- 238000001514 detection method Methods 0.000 claims abstract description 75
- 238000009413 insulation Methods 0.000 claims abstract description 33
- 230000008054 signal transmission Effects 0.000 claims description 10
- 238000004891 communication Methods 0.000 claims description 8
- 230000001012 protector Effects 0.000 claims description 7
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 238000009421 internal insulation Methods 0.000 abstract description 4
- 238000012544 monitoring process Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- 230000001276 controlling effect Effects 0.000 description 4
- 230000006870 function Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 241001465754 Metazoa Species 0.000 description 1
- 230000000703 anti-shock Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012806 monitoring device Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000003252 repetitive effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Abstract
The utility model relates to an electric shock protection device, comprising: the device comprises a main loop, a grounding loop, a residual current detection circuit, a control unit MCU, an insulation resistance detection circuit, a voltage detection circuit, a first switch driving circuit and a second switch driving circuit, wherein a first input end of the residual current detection circuit is electrically connected with the main loop, a second input end of the residual current detection circuit is electrically connected with the grounding loop, an output end of the residual current detection circuit is electrically connected with the control unit MCU, and the control unit MCU is further electrically connected with the insulation resistance detection circuit, the first switch driving circuit and the second switch driving circuit respectively, wherein the insulation resistance detection circuit is used for detecting the insulation resistance in the main loop. The electric shock protection device can judge whether the fault position is an internal insulation fault of the power supply or an output circuit insulation fault of the power supply by comparing the current variation of the main circuit and the grounding circuit, and improves the fault positioning accuracy.
Description
Technical Field
The utility model relates to the field of power supply systems, in particular to an electric shock protection device.
Background
The residual current protection switch and the residual current protection device are widely applied to urban and rural power grids and building power supply and distribution systems, and play an important role in protecting life and property safety of people. The electric shock protector is used to prevent accident caused by human body electric shock and leakage, and when the leakage current of circuit or electric equipment is greater than the setting value of the protector or the contact danger of human or animal occurs, it can cut off the accident power supply quickly, avoiding the expansion of accident and ensuring the safety of human body and equipment.
However, the existing protection device against electric shock, such as a voltage circuit breaker with an RCD and a molded case circuit breaker with an RCD, is connected in series in the main circuit, and when the residual current is greater than a setting value, the RCD monitoring device triggers the circuit breaker to disconnect the main circuit, cut off the power supply, and the continuity of power supply is stopped, thus reducing the power supply reliability. If the current residual current setting value is too large, the power supply continuity is improved, but when an electric shock accident occurs, safety accidents are easy to occur. When a fault occurs, according to the requirement of GB50054, the TN power supply system needs to cut off output power supply, and when the fault current accords with a certain current, the IT power supply system only needs to send out an alarm signal, so that the power supply reliability is improved. The TN system is influenced by the distributed capacitance and the Y capacitance to the ground, and has a certain residual current, so that the current common residual current protection device is always a fixed value, when an electric shock accident occurs, the actual electric shock current is possibly far smaller than a current value regulated by GB/T13870, and when a large motor or heavy equipment is started, the current is always provided with a certain residual current, and the residual current easily triggers the residual current protection device, thereby causing misoperation and reducing the power supply reliability.
Disclosure of Invention
The utility model aims to overcome the defects in the prior art and provides an electric shock protection device.
The aim of the utility model is realized by the following technical scheme:
an anti-shock protection device comprising: the device comprises a main loop, a grounding loop, a residual current detection circuit, a control unit MCU, an insulation resistance detection circuit, a first switch driving circuit, a second switch driving circuit and a voltage detection circuit.
The first input end of the residual current detection circuit is electrically connected with the main loop, the second input end of the residual current detection circuit is electrically connected with the grounding loop, the output end of the residual current detection circuit is electrically connected with the control unit MCU, the control unit MCU is further electrically connected with the insulation resistance detection circuit, the first switch driving circuit, the second switch driving circuit and the voltage detection circuit respectively, the insulation resistance detection circuit is used for detecting the insulation resistance value in the main loop, the first switch driving circuit is used for controlling the on-off of the main loop, the second switch driving circuit is used for controlling the on-off of the grounding loop, and the voltage detection circuit is used for detecting the voltage value of the main loop.
Optionally, the residual current detection circuit includes a residual current sensor, a current monitor and a signal acquisition amplifying unit, a detection end of the residual current sensor is connected with the main loop, an output end of the residual current sensor is electrically connected with the signal acquisition amplifying unit, a detection end of the current monitor is connected with the grounding loop, and an output end of the current monitor is electrically connected with the signal acquisition amplifying unit.
Optionally, the residual current detection circuit further comprises a signal transmission unit, the output end of the signal acquisition and amplification unit is electrically connected with the signal transmission unit, and the signal transmission unit is electrically connected with the control unit MCU.
Optionally, the main circuit includes a relay switch K2, and the first switch driving circuit is electrically connected to the relay switch K2.
Optionally, the ground loop includes a ground switch K1, and the second switch driving circuit is electrically connected to the ground switch K1.
Optionally, the electric shock protection device further comprises a voltage detection circuit, a detection end of the voltage detection circuit is used for detecting the voltage of the main loop, and an output end of the voltage detection circuit is electrically connected with the control unit MCU.
Optionally, the electric shock protection device further comprises a communication unit, and the communication unit is electrically connected with the control unit MCU.
Optionally, the electric shock protection device further comprises an auxiliary power supply, and the auxiliary power supply is electrically connected with the control unit MCU, the residual current detection circuit, the voltage detection circuit, the insulation resistance detection circuit, the first switch driving circuit, the second switch driving circuit and the communication unit.
Optionally, the ground loop further comprises an SPD protector connected in parallel with the ground switch K1.
Optionally, the ground loop further comprises a ground resistor, and the ground resistor is connected in parallel with the ground switch.
From the above technical scheme, the application has the following advantages:
1. according to the electric shock protection device, the residual current detection circuit is arranged, so that the current of the main loop and the current of the grounding loop can be detected respectively, namely, when the electric shock protection device works normally, the TN power supply system supplies power, the change of the current of the main loop and the current of the grounding loop are compared, the fault position is judged to be an internal insulation fault of the power supply or an output loop insulation fault of the power supply, the fault positioning accuracy is improved, when the residual current on the local line is larger than the residual current on the main loop, the occurrence of electric leakage in the power supply can be judged, when the residual current on the local line is smaller than the residual current value on the main loop, the zero line in the power supply and the equipotential repeatedly connected with the zero line or the circuit generate secondary faults, when the residual current on the local line is equal to the residual current in the main loop, the power supply is normal, and when the setting value is exceeded, the circuit can be changed into the IT power supply system. When the sudden increase of the residual current is detected, whether the residual current is in a leakage phenomenon of the power supply system or the normal start of large equipment is judged by comparing the residual current waveform caused by the start of a large load in the system, so that the accuracy of the residual current is improved.
2. According to the utility model, by arranging the grounding switch K1 and the relay switch K2, when the leakage phenomenon occurs in the TN power supply system, the grounding switch K1 can be disconnected, so that the TN power supply system can be switched into an IT power supply system, and the insulation resistance detection circuit and the residual current detection circuit work simultaneously and perform fault warning.
3. According to the utility model, by arranging the residual current detection circuit and the insulation resistance detection circuit, the advantages of the TN power supply system and the IT power supply system in the aspect of safe power supply are combined, the TN power supply system is used for normal power supply, the mode of electric shock protection is the mode which is most suitable for the TN power supply system, when electric shock occurs, the power supply mode is switched into the IT power supply system by the TN power supply system, the load is not cut off immediately, and the power supply continuity is improved. After the protection mode is switched to the IT power supply system, the protection mode is changed from a residual current protection mode to a protection mode combining residual current with online insulation monitoring, an alarm signal is sent out, and the protection requirement of the IT system meets the national relevant standard requirement.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort to a person skilled in the art.
FIG. 1 is a schematic block diagram of an electric shock protection device according to an embodiment of the present utility model;
fig. 2 is a schematic block diagram of an electric shock protection device according to another embodiment of the present utility model.
Detailed Description
In order that the utility model may be readily understood, a more complete description of the utility model will be rendered by reference to the appended drawings. The drawings illustrate preferred embodiments of the utility model. This utility model may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Referring to fig. 1, an electric shock protection device includes: the device comprises a main loop, a grounding loop, a residual current detection circuit, a control unit MCU, an insulation resistance detection circuit, a voltage detection circuit, a first switch driving circuit and a second switch driving circuit.
The first input end of the residual current detection circuit is electrically connected with the main loop, the second input end of the residual current detection circuit is electrically connected with the grounding loop, the output end of the residual current detection circuit is electrically connected with the control unit MCU, the control unit MCU is further electrically connected with the insulation resistance detection circuit, the first switch driving circuit and the second switch driving circuit respectively, the insulation resistance detection circuit is used for detecting the insulation resistance value in the main loop, the first switch driving circuit is used for controlling the on-off of the main loop, and the second switch driving circuit is used for controlling the on-off of the grounding loop.
Therefore, the residual current detection circuits are arranged to respectively detect the current of the main loop and the ground loop, namely, when the power supply system works normally, the TN power supply system supplies power, the change of the current of the main loop and the ground loop is compared, the fault position is judged to be an internal insulation fault of the power supply or an output loop insulation fault of the power supply, the fault positioning accuracy is improved, when the residual current on the local line is larger than the residual current on the main loop, the occurrence of electric leakage in the power supply can be judged, when the residual current on the local line is smaller than the residual current on the main loop, the zero line in the power supply and the equipotential connected with the zero line are repeatedly grounded or the circuit is subjected to secondary fault, when the residual current on the local line is equal to the residual current in the main loop, the power supply is normal, and when the setting value is exceeded, the circuit can be changed into the IT power supply system. When the sudden increase of the residual current is detected, whether the residual current is in a leakage phenomenon of a power supply system or normal starting of large equipment is judged by comparing residual current waveforms caused by starting of large loads in the system, if the residual current is detected, which is caused by normal starting of the large equipment, the residual current protection switch and the device do not act, and if the residual current is detected, the residual current protection switch and the device are switched to an IT power supply system for power supply by a TN power supply system, so that the protection accuracy of the residual current protection switch and the device is further improved.
Referring to fig. 1-2, the residual current detection circuit includes a residual current sensor, a current monitor, a residual current testing unit and a signal acquisition amplifying unit, wherein a detection end of the residual current sensor is connected with the main loop, an output end of the residual current sensor is electrically connected with the signal acquisition amplifying unit, a monitoring end of the current monitor is connected with the ground loop, an output end of the residual current testing unit generates a residual current in the residual current sensor, an input end of the residual current testing unit is electrically connected with the signal transmission unit, and an output end of the current monitor is electrically connected with the signal acquisition amplifying unit.
In this embodiment, the residual current detection circuit further includes a signal transmission unit, an output end of the signal acquisition and amplification unit is electrically connected to the signal transmission unit, and the signal transmission unit is electrically connected to the control unit MCU.
The main circuit includes a relay switch K2, and the first switch driving circuit is electrically connected to the relay switch K2. The ground circuit comprises a ground switch K1, and the second switch driving circuit is electrically connected with the ground switch K1. Therefore, by arranging the grounding switch K1 and the relay switch K2, the grounding switch K1 can be disconnected when the leakage phenomenon occurs in the TN power supply system, so that the TN power supply system can be switched into an IT power supply system, and the insulation resistance detection circuit and the residual current detection circuit work simultaneously and perform fault warning.
Referring to fig. 1, the electric shock protection device further includes a voltage detection circuit, a detection end of the voltage detection circuit is used for detecting a voltage of the main loop, and an output end of the voltage detection circuit is electrically connected with the control unit MCU. The electric shock protection device further comprises a communication unit, and the communication unit is electrically connected with the control unit MCU. The electric shock protection device further comprises an auxiliary power supply, and the auxiliary power supply is electrically connected with the control unit MCU, the residual current detection circuit, the voltage detection circuit, the insulation resistance detection circuit, the first switch driving circuit, the second switch driving circuit and the communication unit. The ground loop also comprises an SPD protector, and the SPD protector is connected with the ground switch K1 in parallel. The ground loop also comprises a ground resistor, and the ground resistor is connected with the K1 switch in parallel.
The working process comprises the following steps:
during normal operation, the ground wire switch K1 is closed, the main circuit switch K2 is closed, the power supply mode is a TN power supply system, under the power supply system, the main electric shock protection mode is to detect the residual current in the main circuit and/or the ground wire current on the grounding circuit, and when the space geometrical parameters, the working frequency and the ground distributed capacitance of the power transformer are smaller, the residual current in the main circuit and the ground wire current on the grounding circuit are almost equal. When the space geometrical parameters, the working frequency and the transformer-to-ground distributed capacitance of the power transformer are higher, the current values of the power transformer and the working frequency are larger. By comparing the variation of the current of the two, the fault position is judged to be an internal insulation fault of the power supply or an insulation fault of an output loop of the power supply, the fault positioning accuracy is improved, when the residual current on the local line is larger than the residual current on the main loop, the occurrence of the electric leakage condition in the power supply can be judged, when the residual current on the local line is smaller than the residual current value on the main loop, the zero line in the power supply and the equipotential repetitive grounding or the circuit connected with the zero line can be judged to have secondary faults, when the residual current on the local line is equal to the residual current in the main loop, the power supply is normal, and when the residual current exceeds the setting value, the circuit can be provided with a TN power supply system to be changed into an IT power supply system. When the sudden increase of the residual current is detected, whether the power supply system is in a leakage phenomenon or not is judged by comparing residual current waveforms caused by the starting of a large load in the system, or the large equipment is started normally, if the residual current caused by the normal starting of the large equipment is detected, the residual current protection switch and the device do not act, and if the residual current is detected, the residual current protection switch and the device are switched to the IT power supply system for power supply by the TN power supply system, so that the protection accuracy of the residual current protection switch and the device is further improved.
In order to verify that the detection precision and the protection function of the electric shock protection device meet the protection requirements anyway after long-term operation, the on-line test can be performed manually or automatically. The online test is performed by verifying the residual current generated in the residual current sensor by a residual current testing unit in the residual current monitoring circuit, and the test can be performed manually or in a planned manner by a control unit MCU.
When the electric shock protection device detects that the leakage phenomenon occurs in the TN power supply system, the grounding switch K1 is disconnected, the TN power supply system is switched to the IT power supply system, the insulation resistance detection circuit and the residual current monitoring circuit work simultaneously, and meanwhile fault warning is carried out. When the on-line insulation monitoring circuit monitors that the insulation resistance of the insulation IT power supply system is smaller than the lowest threshold value, if the load level of the power supply is the load level of the second level or below, the main loop is disconnected, the operation safety of the system is ensured, and if the load level is the first-level or special-level load, the main loop can be set to be not disconnected according to the power supply reliability requirement, the residual current value is still monitored, and an alarm signal is sent.
And during the K1 opening period, if the insulation resistance value is detected to be larger than the threshold value B, the K1 switch is closed again, and the power supply mode is returned to the normal TN power supply system mode. During the off period of the grounding switch K1, if an atmospheric overvoltage phenomenon occurs, the SPD protector connected in parallel with the grounding switch K1 can realize the function of surge suppression, and the suppression size is determined by the actual lightning protection level. The ESD discharge is discharged by a high resistance resistor in parallel with K1, however, whether a high resistance resistor is required in parallel with K1 is determined by the working environment of the system and the size of the system.
It should be further noted that, except for the special power supply requirement, the general power supply system is a TN power supply system at present, and the protection mode is designed according to the requirement of the TN power supply system. The scheme combines the advantages of the TN power supply system and the IT power supply system in the aspect of safe power supply, and for specific power supply scenes (the TN power supply system and the IT power supply system are different in safety performance under different power supply radiuses and load characteristics), the TN power supply system is powered on in a normal power supply mode, the mode of electric shock protection is the mode which is most suitable for the TN power supply system, when electric shock occurs (when residual current exceeds a set condition, the set condition is intelligent, a residual current value and a normal line leakage current value caused by a large motor or heavy load during starting can be avoided), the power supply mode is switched into the IT power supply system by the TN power supply system instead of immediately cutting off the load, and the reliability of power supply is improved.
After the protection mode is switched to an IT power supply system, the protection mode is changed from a residual current protection mode to a protection mode combining residual current with online insulation monitoring, an alarm signal is sent out, and the protection requirement of the IT system can refer to the requirement of GB50054-2011 (5.2.19).
The residual current monitoring method is improved, and the online learning function is achieved. The residual current generated during the starting of the equipment, the residual current generated by the Y capacitance to the ground in the equipment and the stray capacitance to the ground of the opposite conductor and the residual current under the fault condition can be actively identified through an advanced control algorithm, so that misoperation is reduced, meanwhile, the problem that a power supply circuit of a residual current protection device cannot be installed due to overlarge residual current generated by the equipment starting and the Y capacitance to the ground is avoided, and the protection range is enlarged.
The above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.
Claims (10)
1. An electric shock protection device, comprising: the main loop, the grounding loop, the residual current detection circuit, the control unit MCU, the insulation resistance detection circuit, the first switch driving circuit and the second switch driving circuit,
the first input end of the residual current detection circuit is electrically connected with the main loop, the second input end of the residual current detection circuit is electrically connected with the grounding loop, the output end of the residual current detection circuit is electrically connected with the control unit MCU, the control unit MCU is further electrically connected with the insulation resistance detection circuit, the first switch driving circuit and the second switch driving circuit respectively, the insulation resistance detection circuit is used for detecting the insulation resistance value in the main loop, the first switch driving circuit is used for controlling the on-off of the main loop, and the second switch driving circuit is used for controlling the on-off of the grounding loop.
2. The electric shock protection device according to claim 1, wherein the residual current detection circuit comprises a residual current sensor, a current monitor and a signal acquisition amplifying unit, a detection end of the residual current sensor is connected with the main loop, an output end of the residual current sensor is electrically connected with the signal acquisition amplifying unit, a detection end of the current monitor is connected with the grounding loop, and an output end of the current monitor is electrically connected with the signal acquisition amplifying unit.
3. The electric shock protection device according to claim 2, wherein the residual current detection circuit further comprises a signal transmission unit, an output end of the signal acquisition and amplification unit is electrically connected with the signal transmission unit, and the signal transmission unit is electrically connected with the control unit MCU.
4. The protection device according to claim 1, wherein the main circuit includes a relay switch K2, and the first switch driving circuit is electrically connected to the relay switch K2.
5. The protection device according to claim 1, wherein the ground circuit includes a ground switch K1, and the second switch driving circuit is electrically connected to the ground switch K1.
6. The electric shock protection device according to claim 1, further comprising a voltage detection circuit, wherein a detection end of the voltage detection circuit is used for detecting a voltage of the main loop, and an output end of the voltage detection circuit is electrically connected with the control unit MCU.
7. The protection device of claim 6, further comprising a communication unit electrically connected to the control unit MCU.
8. The protection device according to claim 7, further comprising an auxiliary power source electrically connected to the control unit MCU, the residual current detection circuit, the voltage detection circuit, the insulation resistance detection circuit, the first switch driving circuit, the second switch driving circuit, and the communication unit.
9. The protection device according to claim 5, wherein the ground circuit further comprises an SPD protector connected in parallel with the ground switch K1.
10. The protection device according to claim 5, wherein the ground circuit further comprises a ground resistor connected in parallel with the ground switch K1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321831247.9U CN220605548U (en) | 2023-07-13 | 2023-07-13 | Electric shock protection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321831247.9U CN220605548U (en) | 2023-07-13 | 2023-07-13 | Electric shock protection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220605548U true CN220605548U (en) | 2024-03-15 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202321831247.9U Active CN220605548U (en) | 2023-07-13 | 2023-07-13 | Electric shock protection device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220605548U (en) |
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2023
- 2023-07-13 CN CN202321831247.9U patent/CN220605548U/en active Active
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