CN110596514A - Leakage detection circuit, device and method - Google Patents
Leakage detection circuit, device and method Download PDFInfo
- Publication number
- CN110596514A CN110596514A CN201910880323.7A CN201910880323A CN110596514A CN 110596514 A CN110596514 A CN 110596514A CN 201910880323 A CN201910880323 A CN 201910880323A CN 110596514 A CN110596514 A CN 110596514A
- Authority
- CN
- China
- Prior art keywords
- leakage detection
- circuit
- power supply
- integrated chip
- alternating current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 134
- 238000000034 method Methods 0.000 title abstract description 5
- 238000012360 testing method Methods 0.000 claims abstract description 41
- 230000001360 synchronised effect Effects 0.000 claims abstract description 29
- 230000009471 action Effects 0.000 claims abstract description 18
- 239000000284 extract Substances 0.000 claims abstract description 8
- 239000003990 capacitor Substances 0.000 claims description 24
- 230000005284 excitation Effects 0.000 description 22
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 10
- 229910052710 silicon Inorganic materials 0.000 description 10
- 239000010703 silicon Substances 0.000 description 10
- 238000012544 monitoring process Methods 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 230000005611 electricity Effects 0.000 description 3
- 238000002955 isolation Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
Abstract
The invention discloses a leakage detection circuit, a device and a method, wherein the leakage detection circuit comprises a power supply circuit, a protection circuit and a leakage detection integrated chip; the power supply circuit performs half-wave rectification on the voltage of the alternating current power supply; the leakage detection integrated chip acquires waveform information after half-wave rectification, extracts alternating current synchronous information from the waveform information, and controls the power supply protection circuit to carry out self-test within a time period when the alternating current amplitude is smaller than zero according to the alternating current synchronous information so as to confirm whether the protection circuit is normal or not; the electric leakage detection integrated chip is also used for outputting an electric leakage protection signal when the alternating current amplitude value is larger than a preset threshold value. According to the technical scheme, the protection circuit is subjected to self-detection in the negative half-cycle of half-wave rectification, so that the protection action caused by false triggering is avoided, meanwhile, the power supply circuit can also supply power to the leakage detection integrated chip, the additional arrangement of a power supply is avoided, and the circuit cost is reduced.
Description
Technical Field
The present invention relates to the field of leakage detection technologies, and in particular, to a leakage detection circuit, device, and method.
Background
With the rapid popularization of household appliances, the high-frequency components in the load current of modern equipment are increased, the leakage protection standard is stricter day by day, the domestic standard is 10mA at present, and the international standard is 5mA or below. Meanwhile, the leakage detection protection circuit is required to be periodically tested to ensure normal work and avoid possible damage to human bodies due to error conditions.
In the existing self-test circuit, after the alternating current power supply is reduced, the alternating current synchronous information is provided for the self-test circuit through an additional pin. The method needs additional pins and a high-voltage isolation circuit, so the design is complex, the cost is high, and the reliability of the circuit is low.
Disclosure of Invention
The invention mainly aims to provide a leakage detection circuit, which aims to extract alternating current synchronous information from the waveform of a power supply directly so as to improve the reliability of the leakage detection circuit.
In order to achieve the above object, the present invention provides a leakage detection circuit, which includes a power supply circuit, a protection circuit, and a leakage detection integrated chip; the power supply circuit is connected with an alternating current power supply and is also connected with the electric leakage detection integrated chip; the protection circuit is respectively connected with the electric leakage detection integrated chip and the power supply circuit; wherein
The protection circuit is used for executing protection action when receiving the leakage protection signal;
the power supply circuit is used for carrying out half-wave rectification on the accessed alternating current power supply voltage so as to supply power to the electric leakage detection integrated chip;
the leakage detection integrated chip is used for acquiring half-wave rectified waveform information, extracting alternating current synchronous information from the waveform information, and performing self-test within a time period when the alternating current amplitude is smaller than zero according to the alternating current synchronous information so as to confirm whether the protection circuit and the current transformer are normal or not.
Preferably, the power supply circuit includes a first diode and a first resistor, an anode of the first diode is connected to the action coil, a cathode of the first diode is connected to a first end of the first resistor, and a second end of the first resistor is connected to a power supply terminal of the leakage detection integrated chip.
Preferably, the leakage detection circuit further comprises a protection circuit, and the protection circuit is respectively connected with the leakage detection integrated chip and the power supply circuit; and the protection circuit is used for executing protection action according to the leakage protection signal.
Preferably, the protection circuit includes a first switch tube, a controlled end of the first switch tube is connected to the control end of the leakage detection integrated chip, an input end of the first switch tube is connected to the power supply circuit, and an output end of the first switch tube is grounded.
Preferably, the first switch tube is a thyristor.
Preferably, the power supply circuit includes a second diode and a second resistor; the anode of the second diode is connected with the live wire of the power supply to be detected, the cathode of the second diode is connected with the first end of the second resistor, and the second end of the second resistor is connected with the second power supply of the leakage detection integrated chip.
Preferably, the leakage detection circuit further includes a working indication circuit, and the working indication circuit includes a third resistor and a first light emitting diode; the first end of the third resistor is connected with the self-checking end of the electric leakage detection integrated chip, the anode of the first light-emitting diode is connected, and the cathode of the first light-emitting diode is grounded.
Preferably, the electric leakage detection circuit further includes a first capacitor and a second capacitor, a first end of the first capacitor is connected to the control end of the electric leakage detection integrated chip, a second end of the first capacitor is connected to the ground terminal of the electric leakage detection integrated chip, the ground terminal of the electric leakage detection integrated chip is further connected to the zero line of the alternating current power supply, a first end of the second capacitor is connected to a second end of the first capacitor, and a second end of the second capacitor is further connected to the power end of the electric leakage detection integrated chip.
In order to achieve the above object, the present invention further provides an electrical leakage detection device, which includes the electrical leakage detection circuit as described above.
In order to achieve the above object, the present invention further provides an electric leakage detection method, based on the above electric leakage detection apparatus, the electric leakage detection method including:
the power supply circuit performs half-wave rectification on the accessed alternating current power supply voltage so as to supply power to the electric leakage detection integrated chip;
the leakage detection integrated chip acquires waveform information after half-wave rectification, extracts alternating current synchronous information from the waveform information, and performs self-test in a time period when the alternating current amplitude is smaller than zero according to the alternating current synchronous information to confirm whether the protection circuit and the current transformer are normal or not;
the leakage detection integrated chip is also used for outputting a leakage protection signal when the alternating current amplitude value is larger than a preset threshold value;
the protection circuit executes protection action when receiving the leakage protection signal;
preferably, the leakage detecting integrated chip is initialized when the protection circuit and the current transformer are normal.
According to the technical scheme, the power supply circuit and the electric leakage detection integrated chip are arranged to form the electric leakage detection circuit. The power supply circuit performs half-wave rectification on the voltage obtained by the induction of the alternating current power supply so as to supply power to the electric leakage detection integrated chip; the leakage detection integrated chip acquires waveform information after half-wave rectification, extracts alternating current synchronous information from the waveform information, and performs self-test within a time period when the alternating current amplitude is less than zero according to the alternating current synchronous information to confirm whether the protection circuit is normal or not; the electric leakage detection integrated chip is also used for outputting an electric leakage protection signal when the alternating current amplitude value is larger than a preset threshold value. According to the technical scheme, the protection circuit is subjected to self-detection in the negative half-cycle of half-wave rectification, so that the phenomenon that false triggering is caused to cause protection action is avoided, meanwhile, the power supply circuit can also supply power to the electric leakage detection integrated chip, synchronous information is directly collected from the power supply loop, the additional arrangement of a power supply is avoided, the circuit cost is reduced, and the reliability of the electric leakage detection circuit is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
FIG. 1 is a functional block diagram of an embodiment of a leakage detection circuit according to the present invention;
FIG. 2 is a schematic circuit diagram of an embodiment of a leakage detection device according to the present invention;
fig. 3 is a flowchart illustrating an embodiment of a leakage detection method according to the present invention.
The reference numbers illustrate:
| reference numerals | Name (R) | Reference numerals | Name (R) |
| 100 | Current transformer | R1～R3 | First to third resistors |
| 200 | Power supply circuit | C1～C3 | First to third capacitors |
| 300 | Electric leakage detection integrated chip | D1～D2 | First to second diodes |
| 400 | Protective circuit | L1 | Current transformer |
| 500 | Operation indicating circuit | U1 | Electric leakage detection integrated chip |
| Q1 | Silicon controlled rectifier | D3 | First light emitting diode |
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.
In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should be considered to be absent and not within the protection scope of the present invention.
The invention provides an electric leakage detection circuit.
Referring to fig. 1, in the embodiment of the present invention, the leakage detection circuit includes a current transformer 100, a protection circuit 400, a power supply circuit 200, and a leakage detection integrated chip 300; the leakage detection integrated chip 300 is coupled with the current transformer 100, the power supply circuit 200 is connected with an alternating current power supply, and the power supply circuit 400 is further connected with the leakage detection integrated chip 300; the protection circuit 400 is connected to the leakage detection integrated chip 300 and the power supply circuit 200, respectively; wherein
The protection circuit 400 is configured to perform a protection action when receiving the leakage protection signal. Usually, the protection circuit 400 is provided with a controllable switch tube, in this embodiment, the controllable switch tube adopts a thyristor, and the thyristor is controlled based on the leakage protection integrated chip 300 to be disconnected when performing a protection action, so as to protect the electrical equipment.
The power supply circuit 200 is configured to perform half-wave rectification on the voltage induced by the ac power supply;
the leakage detection integrated chip 300 is configured to obtain waveform information after half-wave rectification, extract alternating current synchronization information from the waveform information, and perform self-test within a time period in which an alternating current amplitude is smaller than a preset threshold value according to the alternating current synchronization information to determine whether the protection circuit 400 is normal; the electric leakage detection integrated chip is also used for outputting an electric leakage protection signal when the alternating current amplitude value is larger than a preset threshold value.
It should be noted that in this embodiment, when performing self-test on the current transformer 100, an excitation power supply may be set as needed, and may be one of a direct current excitation power supply, a low frequency excitation power supply, and a high frequency excitation power supply, or a combination of multiple types. For example, when the preset excitation power supply includes a low-frequency excitation power supply and a high-frequency excitation power supply, the low-frequency excitation power supply and the high-frequency excitation power supply are turned on and operated for 600 milliseconds at the same time, and then turned off for 600 milliseconds, as one working cycle. When the silicon controlled rectifier in the protection circuit is subjected to self test, whether the silicon controlled rectifier works normally can be determined by controlling the on-off of the silicon controlled rectifier and detecting the related voltage of the silicon controlled rectifier.
The current transformer 100 is configured to couple a preset excitation power source to the ac power source. The turns ratio of the current transformer 100 in this embodiment is 1: 1000. The zero line and the live line of the alternating current power supply pass through the magnetic ring of the current transformer 100.
The power supply circuit 200 is configured to rectify the voltage induced by the ac power supply, and simultaneously obtain half-wave rectified waveform information from the leakage detection integrated chip. In this embodiment, when the leakage protection circuit operates, the voltage induced by the ac power supply is rectified to obtain a target monitoring voltage, and the reference voltage is subtracted from the target monitoring voltage to obtain a difference between the target monitoring voltage and the reference voltage.
The protection circuit 400 is provided with leakage protection components such as a thyristor and a release, and since faults such as open circuit and short circuit may occur in the current transformer 100 and the thyristor Q1 during operation, self-testing of these components is required. The embodiment can perform self-test, namely synchronous test, while performing leakage protection. In this embodiment, the synchronous test may be performed in a time period when the ac amplitude is less than zero. It can be understood that, in this embodiment, a period of time may be selected to perform the synchronization test in a time period when the ac amplitude is less than zero, and the setting may be specifically performed according to an actual requirement, which is not limited herein.
It should be noted that the leakage detecting integrated chip 300 is provided with a voltage stabilizing and power supplying module for supplying power to other modules of the chip. The leakage detection integrated chip 300 is further provided with a synchronous test module, a silicon controlled test control module, a test excitation module, a signal amplification and conditioning module, a leakage module function module and a mutual inductor test module. The synchronous test module is used for completing synchronous test.
The leakage detection integrated chip 300 may be integrated with a digital filter, an operational amplifier, an and gate, an or gate, a nor gate and other logic devices (gate circuits), a timing controller, a timer, a D trigger and other hardware circuits, and may also be integrated with a software algorithm to determine whether the electrical equipment leaks electricity according to the power signal detected by the current transformer 100, and the leakage detection integrated chip 300 is also integrated with a self-test software program and a hardware circuit for performing self-test on the thyristor, the current transformer 100 and other components in the leakage protection circuit, so as to implement self-test on the leakage protection circuit while the electrical equipment performs leakage protection, thereby ensuring the safety of the thyristor, the current transformer 100 and other important components in the leakage protection, and improving the reliability of the leakage protection.
It should be noted that, the leakage detection integrated chip 300 tests the protection circuit of the leakage detection integrated circuit (including the chip and the external device) by detecting the ac synchronization information existing in the power supply signal when appropriate (within a certain time period when the ac amplitude is smaller than zero), so as to prevent the test of the thyristor when the ac amplitude is high from causing an erroneous protection action, thereby preventing the trigger of the action protection mechanism during the test. According to the technical scheme of the invention, the power supply circuit 200 is arranged to supply power to the electric leakage detection integrated chip 300, the electric leakage detection integrated chip 300 is used for outputting a power supply signal to a load according to the power supply signal collected by the current sensor 100 and the like, and the electric leakage detection integrated chip 300 is also used for outputting an electric leakage protection signal when the alternating current amplitude of the detected power supply signal is greater than a preset threshold value. And determining whether the electrical equipment suitable for the leakage protection circuit leaks electricity, and controlling the protection circuit 400 to perform leakage protection when the electrical equipment leaks electricity. The power supply circuit 200 of the invention performs half-wave rectification on the voltage of the alternating current power supply 200 to provide a power supply for the leakage detection integrated chip; the leakage detection integrated chip 300 may obtain waveform information after half-wave rectification from the power supply output by the power supply circuit 200, extract ac synchronization information from the waveform information, and perform self-test of the components such as the thyristor and the current transformer 100 in the protection circuit 400 within a time period in which the ac amplitude is less than zero according to the ac synchronization information to determine whether the protection circuit 400 and the current transformer 100 are normal, thereby improving the reliability of leakage protection of the electrical equipment itself; according to the technical scheme, the self-detection can be carried out on the protection circuit in the negative half-cycle of half-wave rectification, so that the protection action caused by false triggering is avoided. In this embodiment, the power supply circuit 200 is a power supply source for the leakage detecting integrated chip 300, and the synchronization signal is directly collected from the power supply circuit 200, so that it is avoided that an additional path of alternating current signal is specially used for providing synchronization information, and therefore, an additional path of synchronous alternating current signal is prevented from being additionally introduced, an additional high-voltage isolation circuit is required, and the additional rectification and the circuit design have large cost in terms of cost and complexity. In other words, the power supply circuit 200 supplies power to the leakage detection integrated chip 300, and the leakage detection integrated chip 300 can sample waveform information in the power supply circuit, so as to obtain a synchronization signal, avoid additional arrangement of a sampling circuit, and reduce the cost of the leakage protection device.
The waveform information may be a voltage amplitude, or a phase of the power supply signal, etc. may be used to embody the waveform information of the power supply signal. The present embodiment may be selected to obtain the phase of the alternating voltage VAC with respect to the power supply signal by monitoring the voltage of the power supply signal, thereby obtaining an appropriate test time. When the voltage of the power supply signal is reduced from high to low and is within a certain range, the test time period can be determined, or the change of the power supply signal is detected, when the slope of the change is positive/negative, the alternating current phase is deduced, or the collected alternating current phase is converted into a digital signal through an analog-digital converter, and then the digital signal is processed and judged according to the collected digital signal.
Referring to fig. 2, in the embodiment, the power supply circuit 200 includes a first diode D1 and a first resistor R1, an anode of the first diode D1 is connected to the zero line of the ac power source, a cathode of the first diode D1 is connected to a first end of the first resistor R1, and a second end of the first resistor R1 is connected to the power source terminal VDD of the integrated leakage detecting chip U1.
The first diode D1 is used to rectify ac power in the ac power supply into dc power. The first resistor is used for limiting current and preventing a large current in the alternating current power supply from burning out a chip.
Further, the leakage detection circuit further includes a protection circuit 400, and the protection circuit 400 is connected to the leakage detection integrated chip 300 and the power supply circuit 200 respectively; the protection circuit 400 is configured to perform a protection action according to the leakage protection signal.
In this embodiment, the protection circuit includes a first switch tube, a controlled end of the first switch tube is connected to the control end of the leakage detection integrated chip 300, an input end of the first switch tube is connected to the power supply circuit 200, and an output end of the first switch tube is grounded. The first switch tube is a thyristor Q1, but other controllable switches, such as a relay, etc., may be used.
When the control terminal Scr of the leakage detection integrated chip 300 outputs a leakage protection signal, the thyristor Q1 is turned on, and the live wire of the ac power supply is connected to the ground, so as to prevent the influence of the leakage of the ac power supply on personal safety.
Specifically, the power supply circuit 200 includes a second diode D2 and a second resistor R2; the anode of the second diode D2 is connected to the live wire of the power source to be tested, the cathode of the second diode D2 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected to the second power source VDD2 of the integrated leakage detecting chip 300. The second diode D2 is used to rectify ac power from the ac power source into dc power. The second resistor R2 is used for limiting current and preventing the chip from being burned out by large current in the alternating current power supply.
Further, the leakage detection circuit further comprises an operation indication circuit 500, wherein the operation indication circuit 500 comprises a third resistor R3 and a first light emitting diode D3; the first end of the third resistor R3 is connected with the self-checking end of the leakage detection integrated chip U1, the anode of the first light-emitting diode D3 is connected, and the cathode of the first light-emitting diode D3 is grounded.
It should be noted that the integrated chip 300 has a self-checking function, and when the self-checking is normal, the working indication circuit emits green light; when the self-checking fails, a red warning light is emitted.
Further, the leakage detection circuit further includes a first capacitor C1 and a second capacitor C2, a first end of the first capacitor C1 is connected to the control terminal Scr of the leakage detection integrated chip U1, a second end of the first capacitor C1 is connected to a ground terminal GND of the leakage detection integrated chip U1, a ground terminal GND of the leakage detection integrated chip U1 is further connected to a power supply zero line of an ac power supply, a first end of the second capacitor C2 is connected to a second end of the first capacitor C1, and a second end of the second capacitor C2 is further connected to a power terminal VDD of the leakage detection integrated chip U1.
The first capacitor C1 and the second capacitor C2 are both used for filtering and stabilizing voltage, so that the voltage input to the port of the leakage detection integrated chip U1 is more stable and accurate.
In this embodiment, the leakage detecting integrated chip 300 further includes an excitation terminal CT and a ground terminal GND, wherein the excitation terminal CT is connected to one end of the current transformer 100, and the second end of the current transformer 100 is connected to the ground terminal GND of the leakage detecting integrated chip U1.
The present invention further provides a leakage protection device, which includes the leakage protection circuit described above, and the specific structure of the leakage protection circuit refers to the above embodiments, and since the leakage protection device adopts all the technical solutions of all the above embodiments, the leakage protection device at least has all the beneficial effects brought by the technical solutions of the above embodiments, and details are not repeated here.
The earth leakage protection device may be an earth leakage protection instrument.
Referring to fig. 3, in order to achieve the above object, the present invention further provides a leakage detection method, which is based on the above leakage detection apparatus, and the leakage detection method includes:
step S100: the power supply circuit performs half-wave rectification on the accessed alternating current power supply voltage so as to supply power to the electric leakage detection integrated chip;
step S200: the leakage detection integrated chip acquires waveform information after half-wave rectification, extracts alternating current synchronous information from the waveform information, and performs self-test in a time period when the alternating current amplitude is smaller than zero according to the alternating current synchronous information to confirm whether the protection circuit and the current transformer are normal or not;
step S300: the leakage detection integrated chip is also used for outputting a leakage protection signal when the alternating current amplitude value is larger than a preset threshold value;
step S400: the protection circuit executes protection action when receiving the leakage protection signal.
It should be noted that in this embodiment, when performing self-test on the current transformer 100, an excitation power supply may be set as needed, and may be one of a direct current excitation power supply, a low frequency excitation power supply, and a high frequency excitation power supply, or a combination of multiple types. For example, when the preset excitation power supply includes a low-frequency excitation power supply and a high-frequency excitation power supply, the low-frequency excitation power supply and the high-frequency excitation power supply are turned on and operated for 600 milliseconds at the same time, and then turned off for 600 milliseconds, as one working cycle. When the silicon controlled rectifier in the protection circuit is subjected to self test, whether the silicon controlled rectifier works normally can be determined by controlling the on-off of the silicon controlled rectifier and detecting the related voltage of the silicon controlled rectifier.
In this embodiment, the synchronous test may be performed in a time period when the ac amplitude is less than zero. It can be understood that, in this embodiment, a period of time may be selected to perform the synchronization test in a time period when the ac amplitude is less than zero, and the setting may be specifically performed according to an actual requirement, which is not limited herein.
It should be noted that the leakage detection ic 300 tests the protection circuit of the leakage detection integrated circuit (including the chip and the external device) by detecting the ac synchronization information existing in the power supply signal when appropriate (a certain period of time within a period of time in which the ac amplitude is smaller than zero). Thereby avoiding triggering the action protection mechanism during testing; since testing the thyristors at high ac amplitudes can lead to erroneous protection actions. According to the technical scheme, the power supply circuit 200 and the electric leakage detection integrated chip are arranged to form the electric leakage detection circuit. The power supply circuit 200 performs half-wave rectification on the voltage of the alternating current power supply 200; the leakage detection integrated chip acquires waveform information after half-wave rectification, extracts alternating current synchronous information from the waveform information, and performs self-test within a time period when the alternating current amplitude is less than zero according to the alternating current synchronous information to confirm whether the protection circuit 400 and the current transformer 100 are normal or not; the leakage detection integrated chip 300 is further configured to output a leakage protection signal when the ac amplitude is greater than a preset threshold. In the technical scheme of the invention, the protection circuit is self-detected in the negative half-cycle of half-wave rectification, so that the protection action caused by false triggering is avoided, in the embodiment, the power supply circuit 200 provides a power supply for the leakage detection integrated chip 300, the synchronous signal is directly collected from the power supply circuit 200, and the condition that an extra path of alternating current signal is specially used for providing synchronous information can be avoided, so that the condition that an extra path of synchronous alternating current signal is additionally introduced, an extra high-voltage isolation circuit is required, extra rectification is required, and the circuit design has higher cost in cost and complexity. In other words, the power supply circuit supplies power to the leakage detection integrated chip, and can also sample waveform information, so that additional arrangement of a sampling circuit is avoided, and the circuit cost is reduced.
The waveform information may be a voltage amplitude, or a phase of the power supply signal, etc. may be used to embody the waveform information of the power supply signal. The present embodiment may be selected to obtain the phase of the alternating voltage VAC with respect to the power supply signal by monitoring the voltage of the power supply signal, thereby obtaining an appropriate test time. When the voltage of the power supply signal is reduced from high to low and is within a certain range, the test time period can be determined, or the change of the power supply signal is detected, when the slope of the change is positive/negative, the alternating current phase is deduced, or the collected alternating current phase is converted into a digital signal through an analog-digital converter, and then the digital signal is processed and judged according to the collected digital signal.
Further, the leakage detection integrated chip is initialized when the protection circuit and the current transformer are normal. After the initialization is completed, the leakage detection is started.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. The electric leakage detection circuit is characterized by comprising a power supply circuit, a protection circuit and an electric leakage detection integrated chip; the power supply circuit is connected with an alternating current power supply and is also connected with the electric leakage detection integrated chip; the protection circuit is respectively connected with the electric leakage detection integrated chip and the power supply circuit; wherein
The protection circuit is used for executing protection action when receiving the leakage protection signal;
the power supply circuit is used for carrying out half-wave rectification on the accessed alternating current power supply voltage so as to supply power to the electric leakage detection integrated chip;
the leakage detection integrated chip is used for acquiring half-wave rectified waveform information, extracting alternating current synchronous information from the waveform information, and performing self-test in a time period with an alternating current amplitude smaller than zero according to the alternating current synchronous information so as to confirm whether the protection circuit and the current transformer are normal or not.
2. The electrical leakage detection circuit of claim 1, wherein the power supply circuit comprises a first diode and a first resistor, an anode of the first diode is connected to the operating coil, a cathode of the first diode is connected to a first terminal of the first resistor, and a second terminal of the first resistor is connected to a power supply terminal of the electrical leakage detection integrated chip.
3. The leakage detection circuit of claim 1, wherein the protection circuit comprises a first switch tube, a controlled terminal of the first switch tube is connected to the control terminal of the leakage detection ic, an input terminal of the first switch tube is connected to the power supply circuit, and an output terminal of the first switch tube is grounded.
4. The electrical leakage detection circuit of claim 3, wherein the first switching tube is a thyristor.
5. The electrical leakage detection circuit of claim 1, wherein the power supply circuit comprises a second diode and a second resistor; the anode of the second diode is connected with the live wire of the power supply to be detected, the cathode of the second diode is connected with the first end of the second resistor, and the second end of the second resistor is connected with the second power supply of the leakage detection integrated chip.
6. The leakage detection circuit of claim 1, further comprising an operation indication circuit, the operation indication circuit comprising a third resistor and a first light emitting diode; the first end of the third resistor is connected with the self-checking end of the electric leakage detection integrated chip, the anode of the first light-emitting diode is connected, and the cathode of the first light-emitting diode is grounded.
7. The electrical leakage detection circuit according to claim 1, wherein the electrical leakage detection circuit further comprises a first capacitor and a second capacitor, a first end of the first capacitor is connected to the control terminal of the electrical leakage detection integrated chip, a second end of the first capacitor is connected to a ground terminal of the electrical leakage detection integrated chip, the ground terminal of the electrical leakage detection integrated chip is further connected to a zero line of an alternating current power source, a first end of the second capacitor is connected to a second end of the first capacitor, and a second end of the second capacitor is further connected to a power terminal of the electrical leakage detection integrated chip.
8. An electrical leakage detection device, characterized in that the electrical leakage detection device comprises an electrical leakage detection circuit according to any one of claims 1 to 7.
9. An electric leakage detection method based on the electric leakage detection device according to claim 8, characterized by comprising:
the power supply circuit performs half-wave rectification on the accessed alternating current power supply voltage so as to supply power to the electric leakage detection integrated chip;
the leakage detection integrated chip acquires waveform information after half-wave rectification, extracts alternating current synchronous information from the waveform information, and performs self-test in a time period when the alternating current amplitude is smaller than zero according to the alternating current synchronous information to confirm whether the protection circuit and the current transformer are normal or not;
the leakage detection integrated chip is also used for outputting a leakage protection signal when the alternating current amplitude value is larger than a preset threshold value;
the protection circuit executes protection action when receiving the leakage protection signal.
10. The leakage detection method according to claim 9, wherein the leakage detection ic initializes when the protection circuit and the current transformer are normal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910880323.7A CN110596514A (en) | 2019-09-17 | 2019-09-17 | Leakage detection circuit, device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910880323.7A CN110596514A (en) | 2019-09-17 | 2019-09-17 | Leakage detection circuit, device and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110596514A true CN110596514A (en) | 2019-12-20 |
Family
ID=68860467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910880323.7A Pending CN110596514A (en) | 2019-09-17 | 2019-09-17 | Leakage detection circuit, device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110596514A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112162214A (en) * | 2020-08-26 | 2021-01-01 | 浙江朗威微系统有限公司 | Periodic test device and method for leakage detection circuit |
| CN113391234A (en) * | 2021-05-17 | 2021-09-14 | 深圳市合广测控技术有限公司 | Electric leakage detection method, control device and electric leakage detection equipment |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101483297A (en) * | 2008-01-11 | 2009-07-15 | 黄华道 | Electric power plug with leakage protection function |
| JP2010177067A (en) * | 2009-01-30 | 2010-08-12 | Mitsubishi Electric Corp | Earth leakage breaker |
| CN101872957A (en) * | 2009-04-27 | 2010-10-27 | 黄华道 | Leakage current detection protection circuit |
| CN205070397U (en) * | 2015-11-06 | 2016-03-02 | 国网山东郓城县供电公司 | Electric wire netting intelligence earth -leakage protector |
| CN211528651U (en) * | 2019-09-17 | 2020-09-18 | 深圳市晶扬电子有限公司 | Electric leakage detection circuit and device |
-
2019
- 2019-09-17 CN CN201910880323.7A patent/CN110596514A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101483297A (en) * | 2008-01-11 | 2009-07-15 | 黄华道 | Electric power plug with leakage protection function |
| JP2010177067A (en) * | 2009-01-30 | 2010-08-12 | Mitsubishi Electric Corp | Earth leakage breaker |
| CN101872957A (en) * | 2009-04-27 | 2010-10-27 | 黄华道 | Leakage current detection protection circuit |
| CN205070397U (en) * | 2015-11-06 | 2016-03-02 | 国网山东郓城县供电公司 | Electric wire netting intelligence earth -leakage protector |
| CN211528651U (en) * | 2019-09-17 | 2020-09-18 | 深圳市晶扬电子有限公司 | Electric leakage detection circuit and device |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112162214A (en) * | 2020-08-26 | 2021-01-01 | 浙江朗威微系统有限公司 | Periodic test device and method for leakage detection circuit |
| CN112162214B (en) * | 2020-08-26 | 2024-05-03 | 浙江朗威微系统有限公司 | Periodic test device and method for leakage detection circuit |
| CN113391234A (en) * | 2021-05-17 | 2021-09-14 | 深圳市合广测控技术有限公司 | Electric leakage detection method, control device and electric leakage detection equipment |
| CN113391234B (en) * | 2021-05-17 | 2023-12-12 | 深圳市合广测控技术有限公司 | Leakage detection method, control device and leakage detection equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11831139B2 (en) | Processor-based circuit interrupting devices | |
| US7414818B2 (en) | Receptacle type ground-fault circuit interrupter | |
| CN102792538B (en) | Method and apparatus for supervisory circuit for ground fault circuit interrupt device | |
| US9906014B2 (en) | Circuit protection device with automatic fault monitoring and detection function | |
| US8513964B2 (en) | Circuit interrupter device with self-test function | |
| US7764182B2 (en) | Flame sensing system | |
| CN111864694B (en) | Residual current protection circuit | |
| US9535106B2 (en) | Leakage current detection device for appliances | |
| CN110596514A (en) | Leakage detection circuit, device and method | |
| CN102792539A (en) | Method and apparatus for supervisory circuit for ground fault circuit interrupt device | |
| CN108369881A (en) | The ground fault circuit interrupter that frequency of use is recognized and measured | |
| US10461520B2 (en) | Controllable test-pulse width and position for self-test ground fault circuit interrupter | |
| CN108879596A (en) | A kind of leakage protection circuit with power supply monitoring function | |
| CN211528651U (en) | Electric leakage detection circuit and device | |
| CN110011271A (en) | Earth leakage breaker | |
| US10498132B2 (en) | Methods and apparatus to disable a trip circuit during self test in ground fault circuit interrupters | |
| KR20190039191A (en) | 2-step self-test circuit for microcontroller unit and antenna | |
| CN110676808B (en) | Silicon controlled rectifier fault self-testing method, circuit, connector and electrical equipment | |
| CN110649562A (en) | Circuit breaker and working state detection method thereof | |
| CN207381953U (en) | Arc, earth leakage | |
| CN214252508U (en) | Electric leakage test detection device of circuit breaker | |
| WO2022226047A2 (en) | Ground fault circuit interrupter with integrated controller | |
| CN112834950B (en) | Electric leakage detection circuit, electric leakage protection circuit and household appliance | |
| US20220091187A1 (en) | Arc fault circuit interrupt tester and method | |
| CN217931907U (en) | Voltage withstand detection circuit and device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |