WO2021174938A1

WO2021174938A1 - Electrical leakage induction element, electrical leakage detection circuit and water heater

Info

Publication number: WO2021174938A1
Application number: PCT/CN2020/135074
Authority: WO
Inventors: 盛保敬; 白智锐; 陈小雷
Original assignee: 青岛经济技术开发区海尔热水器有限公司; 海尔智家股份有限公司
Priority date: 2020-03-02
Filing date: 2020-12-10
Publication date: 2021-09-10
Also published as: CN113359059A

Abstract

An electrical leakage induction element (2), an electrical leakage detection circuit (100) and a water heater. The electrical leakage induction element (2) comprises: a conductor (20) to be subjected to detection and a detection conductor (40), wherein the conductor to be subjected to detection (20) is connected to a position at which test is to be carried out; and the detection conductor (40) and the conductor to be subjected to detection (20) are spaced apart from each other to constitute an induction capacitor, and the induction capacitor is used for detecting an electrical leakage voltage.

Description

Leakage sensing element, leakage detection circuit and water heater

This disclosure claims the priority of a Chinese patent application filed with the Chinese Patent Office with an application number of 202010135868.8 on March 02, 2020, and the entire content of the above application is incorporated into this disclosure by reference.

Technical field

This application relates to the technical field of electrical leakage detection, such as a leakage induction element, a leakage detection circuit and a water heater.

Background technique

As a kind of home appliance, water heater has been favored by people in recent years. However, there is a risk of electricity leakage during the use of water heaters, and the personal injury caused by electricity leakage is huge. Therefore, the research on leakage detection of water heaters and other electrical appliances has always attracted attention.

In related technologies, water heaters mostly use leakage induction elements such as leakage protection switches or leakage coils to sense leakage current. However, leakage protection switches or leakage coils have a large operating current, and they will generally act after the user gets an electric shock to trigger leakage protection. . Therefore, the leakage induction element in the related art has a problem of poor reliability.

Summary of the invention

The application provides a leakage induction element, a leakage detection circuit and a water heater to improve the reliability of leakage induction.

In the first aspect, this application provides a leakage induction element, including:

The measured conductor and the detection conductor; the measured conductor is connected to the position to be tested; the detection conductor and the measured conductor are spaced apart to form an inductive capacitor, and the inductive capacitor is used to detect a leakage voltage.

In a second aspect, the present application also provides a leakage detection circuit, including: a leakage control circuit and the leakage induction element according to any embodiment of the application, the leakage control circuit is electrically connected to the detection conductor, and the leakage control circuit is electrically connected to the detection conductor. The control circuit is configured to generate a leakage protection signal according to the received leakage induced voltage generated by the detection conductor and the reference point.

In the third aspect, the present application also provides a water heater, including the leakage detection circuit as described in any embodiment of the present application.

Description of the drawings

FIG. 1 is a schematic structural diagram of a leakage induction element provided by an embodiment of the application;

2 is a schematic cross-sectional structure diagram of the leakage induction element shown in FIG. 1;

FIG. 3 is a schematic structural diagram of another leakage induction element provided by an embodiment of the application;

4 is a schematic structural diagram of another leakage induction element provided by an embodiment of the application;

5 is a schematic circuit diagram of a leakage detection circuit provided by an embodiment of the application;

Fig. 6 is a schematic structural diagram of a water heater provided by an embodiment of the application.

Detailed ways

The application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described here are only used to explain the present application. In addition, it should be noted that, for ease of description, the drawings only show a part of the structure related to the present application instead of all of the structure.

The embodiments of the present application provide a leakage induction element, which may be suitable for the leakage induction of electrical products. FIG. 1 is a schematic structural diagram of a leakage induction element provided by an embodiment of the application. 1, the leakage induction element includes: a conductor 20 to be tested and a detection conductor 40; the conductor to be tested 20 is connected to the position to be tested, and the detection conductor 40 and the conductor 20 to be tested are spaced apart to form an induction capacitor, which is used for detection Leakage voltage.

Among them, the definition of capacitance is two conductors close to each other with a layer of insulating medium in between. In the embodiment of the present application, the detecting conductor 40 and the measured conductor 20 are two conductors close to each other, and the insulating structure or air on the substrate 10 is an insulating medium sandwiched between the conductors.

Illustratively, the measured conductor 20 is connected to the position to be detected of the water heater through a wire. Optionally, the measured conductor 20 is connected to the wire through a terminal 30 to simplify the wiring procedure. When the water heater leaks, the AC voltage of the mains 220V will be transmitted to the position to be detected of the water heater. The AC voltage is transmitted to the measured conductor 20 through the wire, and the voltage change generated on the measured conductor 20 is coupled to the detection conductor 40. Therefore, by detecting the coupling voltage of the detection conductor 40, the voltage change of the conductor 20 under test can be detected, thereby detecting the leakage of the position to be tested.

In the embodiment of the present application, the measured conductor 20 and the detection conductor 40 are arranged in the leakage inductance measuring element to form an induction capacitor. The induction capacitor can induce leakage voltage, that is, a non-electric contact method is used to detect whether the location to be tested is electrified. That is to say, even if the user does not get an electric shock under the action of the leakage voltage, the embodiment of the present application can also detect the leakage. Compared with the technical solution of detecting leakage current in the related art, the embodiment of the present application can detect the leakage before the user gets an electric shock. Therefore, the embodiment of the present application has higher reliability for leakage induction. In addition, the leakage inductance sensing element provided by the embodiments of the present application has a simple structure and low cost. In summary, the embodiments of the present application improve the reliability of leakage induction and are easy to implement on the basis of lower cost.

On the basis of the foregoing embodiments, optionally, the leakage induction element further includes at least one substrate. The measured conductor 20 and the detection conductor 40 may be located on the substrate, and the substrate may provide support for the measured conductor 20 and the detection conductor 40. Wherein, the measured conductor 20 and the detecting conductor 40 are arranged on the same substrate, or the measured conductor 20 and the detecting conductor 40 are arranged on different substrates.

It should be noted that, in the above embodiments, the number of substrates may be one or more, and the substrate may be a single panel, or a double panel or multiple panels. The following describes how to set up the substrate.

Continuing to refer to FIG. 1, in an embodiment of the present application, optionally, the measured conductor 20 and the detecting conductor 40 are located on the same substrate 10, and the measured conductor 20 and the detecting conductor 40 are located on the same wiring layer of the substrate 10.

Wherein, the substrate 10 may be, for example, a printed circuit board (Printed Circuit Boards, PCB) substrate, and the substrate 10 provides support for circuit structures such as the measured conductor 20 and the detection conductor 40. Exemplarily, the substrate 10 is a single panel, the substrate 10 is provided with only one wiring layer, and each conductive element in the leakage induction element can be provided on this wiring layer. This arrangement simplifies the arrangement of the substrate 10, thereby helping to reduce the manufacturing cost of the leakage induction unit.

Continuing to refer to FIG. 1, in an embodiment of the present application, optionally, the length of the detection conductor 40 and the length of the measured conductor 20 are equal, that is, the detection conductor 40 and the measured conductor 20 are directly opposite. This arrangement, on the one hand, is conducive to reducing the size of the substrate; on the other hand, the detection conductor 40 and the measured conductor 20 have a larger facing area, and the voltage coupling of the measured conductor 20 is better, which is beneficial to increase the detection conductor 40 and the measured conductor 20. The sensitivity of the induced voltage of the induced capacitance formed by the conductor 20 under test.

FIG. 2 is a schematic cross-sectional structure diagram of the leakage induction element shown in FIG. 1. Referring to Figure 2, in an embodiment of the present application, optionally, the leakage induction element further includes a first auxiliary conductor 70 and a second auxiliary conductor 80; On the other hand, the second auxiliary conductor 80 is located on the side of the detection conductor 80 away from the substrate 10. With this arrangement, the thickness of the conductor 20 and the detection conductor 40 to be measured can be greater than the thickness of other wires on the substrate 10. The arrangement of the embodiment of the application in this way increases the area of the conductor under test 20 and the detection conductor 40 facing each other, thereby increasing the voltage coupling degree of the conductor under test 20, and increasing the inductance formed by the conductor under test 40 and the conductor under test 20. Sensitivity of capacitance induced voltage.

It should be noted that, in actual applications, when the insulation requirements are met, the distance between the conductor 20 and the detection conductor 40 to be tested is set as close as possible, which is beneficial to increase the voltage coupling degree of the conductor 20 to be tested and increase The sensitivity of the induced voltage of the induced capacitance formed by the detection conductor 40 and the measured conductor 20.

FIG. 3 is a schematic structural diagram of another leakage induction element provided by an embodiment of the application. Referring to FIG. 3, in an embodiment of the present application, optionally, the measured conductor 20 and the detection conductor 40 are located on the same substrate 10, the substrate 10 is a double-sided board, the substrate 10 includes two wiring layers, and the measured conductor 20 and the detection conductor 40 are located on different wiring layers of the substrate 10; and the detection conductor 40 and the conductor under test 20 overlap in a direction perpendicular to the substrate 10. Illustratively, the two wiring layers of the substrate 10 are respectively located on the front and back of the substrate 10, the conductor under test 20 is located on the wiring layer on the back of the substrate 10, and the detection conductor 40 is located on the wiring layer on the front of the substrate 10. The detection conductor 40 and the measured conductor 20 overlap in a direction perpendicular to the substrate 10 so that the detection conductor 40 and the measured conductor 20 form an induction capacitance. This arrangement makes the detection conductor 40 and the measured conductor 20 have a larger facing area compared with the substrate 10 as a single panel. Therefore, the voltage coupling degree of the measured conductor 20 is better, and the detection conductor 40 and the measured conductor are increased. The sensitivity of the induced voltage of the induced capacitance formed by 20.

It should be noted that, in actual applications, under the condition that the strength of the substrate 10 and other process requirements are met, the thickness of the double-sided board can be set to be thinner, thereby reducing the distance between the measured conductor 20 and the detecting conductor 40, thereby It is beneficial to increase the voltage coupling degree of the conductor 20 under test, and increase the sensitivity of the induced voltage of the induced capacitance formed by the detection conductor 40 and the conductor under test 20.

In an embodiment of the present application, optionally, the substrate 10 is a multi-panel, the substrate 10 includes a multilayer wiring layer, and the measured conductor 20 and the detection conductor 40 are located in two adjacent wiring layers, thereby reducing The separation distance between the measured conductor 20 and the detection conductor 40 is beneficial to increase the voltage coupling degree of the measured conductor 20 and increase the sensitivity of the induced voltage of the induced capacitance formed by the detection conductor 40 and the measured conductor 20.

In an embodiment of the present application, optionally, the substrate 10 includes at least two wiring layers, and the measured conductor 20 and the detection conductor 40 are located in different wiring layers. If the area of the measured conductor 20 is smaller than that of the detection conductor 40 Area, the detection conductor 40 covers the measured conductor 20; if the area of the measured conductor 20 is greater than the area of the detection conductor 40, the measured conductor 20 covers the detection conductor 40; if the shape and size of the measured conductor 20 are the same as the detection conductor 40 , The measured conductor 20 and the detection conductor 40 overlap. This arrangement increases the voltage coupling degree of the conductor 20 under test, and increases the sensitivity of the induced voltage of the induced capacitance formed by the detection conductor 40 and the conductor under test 20.

1 to 3, on the basis of the foregoing embodiments, optionally, the leakage induction element further includes a shielding conductor 50, the shielding conductor 50 is arranged on the substrate 10, and the shielding conductor 50 is arranged adjacent to the detection conductor 40, The shielding conductor 50 is used for shielding the interference of the external circuit to the detection conductor 40, so as to prevent the detection conductor 40 from being interfered by the electrical signals of other circuits, and improve the reliability of leakage induction.

In an embodiment of the present application, optionally, the shielding conductor 50 is arranged floating, and the shielding conductor 50 does not need to be connected to other circuit structures, so as to simplify the circuit structure.

In an embodiment of the present application, optionally, the shielding conductor 50 is electrically connected to the neutral line, or the shielding conductor 50 is electrically connected to the digital ground of the control circuit, or the shielding conductor 50 is electrically connected to the analog ground of the control circuit. The embodiment of the present application is arranged in this way to keep the potential of the shielding conductor 50 constant, which enhances the shielding effect of the shielding conductor 50 on the electrical signals of other circuits.

In an embodiment of the present application, optionally, the area of the shielding conductor 50 is larger than the area of the detecting conductor 40. According to the inventor’s research, the larger the area of the shielding conductor 50, the better the shielding effect of the shielding conductor 50; in addition, since the shielding conductor 50 is electrically connected to the ground, the larger the shielding conductor 50 is, the more favorable it is for low signal stability. Thereby, the accuracy of detecting leakage of the detecting conductor 40 is improved.

It should be noted that FIGS. 1 to 3 exemplarily show that the shielding conductor 50 is a sheet-shaped polygon, and the shielding conductor 50 is arranged in parallel with the detection conductor 40. In other embodiments, the shielding conductor 50 may also have other shapes. It can be set as required in actual applications. Exemplarily, the shielding conductor 50 has a ring shape, and the shielding conductor 50 surrounds the periphery of the detection conductor 40 to enhance the shielding effect of the shielding conductor 50 on other circuit electrical signals.

1 to 3, on the basis of the foregoing embodiments, optionally, the leakage induction element further includes a detection circuit 60, the detection circuit 60 is provided on the substrate 10, the detection circuit 60 is electrically connected to the detection conductor 40, and the detection circuit 60 is used to perform signal processing on the received leakage induced voltage on the detection conductor 40. Illustratively, the detection circuit 60 includes an amplifier to amplify the voltage induced on the detection conductor 40. The embodiment of the present application is provided with the detection circuit 60, which can make the voltage signal induced on the detection conductor 40 clearer, and the processed induced voltage signal can be directly input into the subsequent circuit. Continuing to refer to FIG. 1, a protrusion is provided at one end of the detection conductor 40 to facilitate the electrical connection between the detection conductor 40 and the detection circuit 60.

It should be noted that in the foregoing embodiments, it is exemplarily shown that the measured conductor 20 and the detection conductor 40 are located on the same substrate 10. In other embodiments, the measured conductor 20 and the detection conductor 40 may be located on different substrates. The case where the measured conductor 20 and the detection conductor 40 are located on different substrates will be described below.

FIG. 4 is a schematic structural diagram of another leakage induction element provided by an embodiment of the application. Referring to FIG. 4, in an embodiment of the present application, optionally, the measured conductor 20 and the detection conductor 40 are located on different substrates 10, and the leakage induction element includes a first substrate 11 and a second substrate 12 arranged in parallel; The measuring conductor 20 is disposed on the first substrate 11, and the detecting conductor 40 is disposed on the second substrate 12; and the detecting conductor 40 and the conductor under test 20 overlap in a direction perpendicular to the first substrate 11. On the one hand, the embodiment of the present application reduces the distance between the detecting conductor 40 and the conductor under test 20 by reducing the distance between the first substrate 11 and the second substrate 12, thereby increasing the voltage coupling degree of the conductor under test 20. , Increase the sensitivity of the induced voltage of the induced capacitance formed by the detection conductor 40 and the measured conductor 20; on the other hand, the embodiment of the present application can increase the measured conductor by increasing the area of the detection conductor 40 and the measured conductor 20 The voltage coupling degree of 20 increases the sensitivity of the induced voltage of the induced capacitance formed by the detecting conductor 40 and the conductor 20 under test.

In an embodiment of the present application, optionally, the number of detecting conductors 40 is multiple, and the number of measured conductors 20 is multiple; the detecting conductors 40 and the measured conductors 20 are in one-to-one correspondence to form multiple sensing conductors. capacitance. The embodiment of the present application is configured in this way to detect the leakage of multiple locations on the electrical appliance, which is beneficial to increase the reliability of the leakage induction element induced leakage.

It should be noted that the plurality of detection conductors 40 and the plurality of measured conductors 20 may be arranged on the same substrate, or may be arranged on different substrates, which can be set as required in practical applications.

It should also be noted that the size of the multiple sensing capacitors can be the same or different, and can be set as required in practical applications. Optionally, if the sizes of the multiple inductive capacitors are different, the reference point of the leakage induced voltage generated by the multiple detection conductors 40 may be the same reference point, which may be the neutral line, or the digital ground of the leakage control circuit, or the reference point of the leakage control circuit. Analog ground. It is also possible to set the reference point of the detection conductor 40 with a larger capacitance as the detection conductor 40 with a smaller capacitance. With this arrangement, when the neutral line, the digital ground of the leakage control circuit, and the analog ground of the leakage control circuit are not pure, the detection conductor 40 with a smaller capacitance can be selected as the reference point, so that the detection conductor 40 with a larger capacitance and the detection conductor 40 with a smaller capacitance can be selected as the reference point. Differential signals are generated between the detection conductors 40, thereby improving the accuracy of detecting the leakage voltage.

The embodiment of the present application also provides a leakage detection circuit. FIG. 5 is a schematic circuit diagram of a leakage detection circuit provided by an embodiment of the application. Referring to Figure 5, the leakage detection circuit includes: a leakage control circuit 1 and a leakage induction element 2 as provided in any embodiment of the present application. The leakage control circuit 1 is electrically connected to a detection conductor, and the leakage control circuit 1 is used to detect the conductor And the leakage induced voltage generated by the reference point to generate a leakage protection signal. Wherein, the reference point can be the neutral line, or the digital ground of the leakage control circuit 1 or the analog ground of the leakage control circuit 1. The leakage detection circuit provided by the embodiment of the present application includes the leakage induction element 2 provided by any embodiment of the present application, and its technical principles and effects are similar, and will not be repeated.

In an embodiment of the present application, optionally, the leakage detection circuit further includes an alarm. When the leakage control circuit 1 receives the leakage induced voltage signal on the detection conductor, the alarm is controlled to give an alarm to remind the presence of electrical appliances. Leakage.

In an embodiment of the present application, optionally, the leakage detection circuit further includes a power-off module. When the leakage control circuit 1 receives the leakage induced voltage signal on the detection conductor, the power-off module controls the power-off module to cut off the power supply of the electrical appliance. Prevent users from getting an electric shock.

The embodiment of the application also provides a water heater. Fig. 6 is a schematic structural diagram of a water heater provided by an embodiment of the application. Referring to FIG. 6, the water heater includes: a leakage detection circuit 100 as provided in any embodiment of the present application. The technical principles and effects are similar, and will not be repeated here.

Continuing to refer to FIG. 6, in an embodiment of the present application, optionally, the terminal of the leakage sensing element in the leakage detection circuit 100 is electrically connected to the protective ground wire of the water heater; or, the terminal of the leakage sensing element is electrically connected to the water heater The housing 200 is electrically connected. Exemplarily, the potential power hazards of the water heater include: the water heater itself does not leak but the protective ground wire that is electrically connected to the water heater is live; or the water heater itself leaks, and the socket or the protective grounding in the building is not good, failing to lead the water heater’s leakage current. Go; or the inner tank of the water heater leaks electricity, and the inner tank of the water heater and the outer shell 200 are connected through a resistor. In the embodiment of the present application, the terminal of the leakage sensing element is connected to the protective ground wire or housing 200 of the water heater, which can detect whether the protective ground wire or housing 200 of the water heater is leaking, and it can also detect whether the inner tank of the water heater is charged through the resistance, thereby avoiding the water heater. The hidden danger of leakage.

In the present application, an inductive capacitor is formed by arranging the measured conductor and the detecting conductor in the leakage inductance measuring element. The inductive capacitor can induce the leakage voltage, that is, the non-electric contact method is used to detect whether the location to be tested is electrified. That is to say, even if the user does not get an electric shock under the action of the leakage voltage, the application can still detect the leakage. Compared with the technical solution of detecting the leakage current in the related art, the leakage current can be detected before the user gets an electric shock. Therefore, the reliability of the leakage induction of the application is higher. In addition, the leakage inductance sensing element provided by the present application has a simple structure and low cost. In summary, this application improves the reliability of leakage induction and is easy to implement on the basis of lower cost.

Claims

A leakage induction element includes: a conductor to be tested and a detection conductor; the conductor to be tested is connected to a position to be tested; the detection conductor and the conductor to be tested are spaced apart to form an induction capacitor, and the induction capacitor is used for Detect leakage voltage.
The leakage induction element according to claim 1, wherein the number of the detection conductor is multiple, and the number of the measured conductor is multiple;

The detecting conductors correspond to the conductors under test one-to-one to form a plurality of the inductive capacitors.
The leakage induction element according to claim 1, further comprising at least one substrate;

The measured conductor and the detection conductor are arranged on the same substrate.
The leakage induction element according to claim 3, wherein the conductor under test and the detection conductor are located on the same wiring layer.
The leakage induction element according to claim 4, further comprising: a first auxiliary conductor and a second auxiliary conductor; the first auxiliary conductor is located on the side of the measured conductor away from the substrate, and the second auxiliary conductor Located on the side of the detection conductor away from the substrate.
The leakage induction element according to claim 3, wherein the substrate includes at least two wiring layers, the conductor under test and the detection conductor are located on different wiring layers; and the detection conductor and the conductor under test are in Overlap in a direction perpendicular to the substrate.
The leakage induction element according to claim 6, wherein the conductor under test and the detection conductor are located in two adjacent wiring layers.
The leakage induction element according to claim 1, further comprising at least two substrates; the measured conductor and the detection conductor are arranged on different substrates.
The leakage induction element according to claim 8, wherein the leakage induction element comprises a first substrate and a second substrate arranged in parallel; the conductor to be measured is arranged on the first substrate, and the detection conductor is arranged on the On the second substrate; and the detection conductor and the measured conductor overlap in a direction perpendicular to the first substrate.
The leakage induction element according to claim 1, further comprising: a shielding conductor, the shielding conductor is arranged adjacent to the detection conductor, and the shielding conductor is used to shield the interference of an external circuit on the detection conductor.
The leakage induction element according to claim 10, wherein the shielding conductor is electrically connected to the neutral line, or the shielding conductor is electrically connected to the digital ground of the control circuit, or the shielding conductor is electrically connected to the analog ground of the control circuit .
The leakage induction element according to claim 10, wherein the area of the shielding conductor is larger than the area of the detecting conductor.
The leakage induction element according to claim 1, further comprising a detection circuit electrically connected to the detection conductor, and the detection circuit is configured to respond to the received detection conductor and the leakage induced voltage generated by the reference point Perform signal processing.
A leakage detection circuit, comprising: a leakage control circuit and the leakage induction element according to any one of claims 1-13, the leakage control circuit is electrically connected to the detection conductor, and the leakage control circuit is configured according to The received leakage induced voltage on the detection conductor generates a leakage protection signal.
A water heater, comprising the leakage detection circuit according to claim 14.