CN216489724U

CN216489724U - Leakage protector

Info

Publication number: CN216489724U
Application number: CN202122695940.5U
Authority: CN
Inventors: 李成力; 陈龙
Original assignee: Suzhou Ele Mfg Co ltd
Current assignee: Suzhou Ele Mfg Co ltd
Priority date: 2021-11-05
Filing date: 2021-11-05
Publication date: 2022-05-10
Anticipated expiration: 2031-11-05

Abstract

The utility model discloses an electric leakage protection device, which comprises an electric leakage detection unit; a switch module; a first driving unit including a first transistor and a reset module; a reset switch; the time delay trigger unit is coupled with the input end of the power supply line, the first driving unit and the reset switch, and is configured to enable the first transistor of the first driving unit to be conducted after a preset time passes after the input end of the leakage protection device is powered on or the reset switch resets the main circuit, so that the switch module is connected with power; and a second driving unit including a second transistor and a trip module, the second transistor being coupled with the trip module, the second driving unit being configured to drive the second transistor to be turned on in response to the leakage detecting unit detecting the presence of the leakage fault signal, thereby causing the switching module to disconnect the power connection. The utility model can avoid the potential safety hazard caused by serious heating of the coil due to frequent driving of the solenoid coil on electricity, thereby protecting the leakage protection device.

Description

Leakage protector

Technical Field

The utility model relates to the electrical field, in particular to an electric leakage protection device.

Background

Some automatic reset type earth leakage protection devices that have now, at input voltage unstability, the artificial power-on operation that resets that repeats, perhaps frequently automatic drive coil power-on easily under the comparatively complicated circumstances of external environment to make the coil generate heat seriously and even burnt and lose, and then make the device lose earth leakage protection function, produce the potential safety hazard.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, the present invention provides an earth leakage protection device, comprising: the leakage detection unit is used for detecting whether a leakage fault signal exists at the load end of the power supply line; a switching module for controlling the electrical connection between the input end of the power supply line and the load end; a first driving unit including a first transistor and a reset module, the first transistor being coupled with the reset module; a reset switch; a delay trigger unit coupled to the input terminal of the power supply line, the first driving unit, and the reset switch, wherein the delay trigger unit is configured to turn on the first transistor of the first driving unit after a predetermined time elapses after the input terminal of the earth leakage protection device is powered on or the reset switch resets the main circuit, so that the reset module is powered on, and the switch module is further connected to the power connection; and a second driving unit including a second transistor and a trip module, the second transistor being coupled to the trip module, the second driving unit being configured to drive the second transistor to conduct in response to the leakage detecting unit detecting the presence of the leakage fault signal, thereby energizing the trip module and further causing the switching module to disconnect the power connection.

In one embodiment, the delay trigger unit includes a rectifying unit, a first resistor, a first capacitor, a second capacitor, a third transistor, and a fourth transistor, a first end of the rectifying unit is coupled to a first input terminal of the input terminals of the power supply line and a second end of the rectifying unit is coupled to a first end of the first resistor, a second end of the first resistor is coupled to a first end of the first capacitor and a second end of the first capacitor is coupled to a second input terminal of the input terminals of the power supply line, a second end of the first resistor is further coupled to a first end of the second capacitor, a first pole of the first transistor is coupled to the reset module, a second pole and a third pole of the first transistor are coupled to a second end of the second capacitor and a second end of the first capacitor, respectively, a first pole and a second pole of the third transistor are coupled to a first end of the first capacitor, a third pole of the third transistor is coupled to the second end of the first capacitor, a first pole and a second pole of the fourth transistor are respectively coupled to the first end of the second capacitor and the first pole of the third transistor, a third pole of the fourth transistor is coupled to the second end of the first capacitor, and the reset switch is coupled to two ends of the first capacitor.

In one embodiment, the delay trigger unit includes a rectifying unit, a first resistor, a first capacitor, a second capacitor, and a third transistor, a first end of the rectifying unit is coupled to a first input terminal of the input terminals of the power supply line and a second end of the rectifying unit is coupled to a first end of the first resistor, a second end of the first resistor is coupled to a first end of the first capacitor, a first pole and a second pole of the third transistor are coupled to a first end of the first capacitor, a third pole of the third transistor is coupled to a first end of the second capacitor, the first pole and the second pole of the first transistor are coupled to the reset module and a second end of the second capacitor, respectively, a third pole of the first transistor is coupled to a second end of the first capacitor, and a second end of the first capacitor is coupled to a second input terminal of the input terminals of the power supply line, the reset switch is coupled to two ends of the first capacitor.

In one embodiment, the rectifying unit is a diode.

In one embodiment, the rectifying unit is a full-bridge rectifying circuit, an input terminal of the full-bridge rectifying circuit is coupled to the input terminal of the power supply line, and an output terminal of the full-bridge rectifying circuit is coupled to the first terminal of the first resistor and the second terminal of the first capacitor.

In one embodiment, the power supply further comprises a ground fault detection unit, the ground fault detection unit is coupled to the second driving unit, and the second driving unit is further configured to drive the second transistor to be turned on in response to the ground fault detection unit detecting that a ground fault signal exists, so as to energize the trip module and further cause the switch module to disconnect the power connection.

In one embodiment, the first transistor, the second transistor, the third transistor, and the fourth transistor are selected from any one of: MOS pipe, silicon controlled rectifier and triode.

In one embodiment, the first transistor, the second transistor, and the third transistor are selected from any one of: MOS pipe, silicon controlled rectifier and triode.

In one embodiment, the reset module and the trip module each include an electromagnetic device.

In one embodiment, the electromagnetic device is a solenoid.

By implementing the technical scheme of the utility model, the potential safety hazard caused by serious heating of the coil due to frequent driving of the solenoid coil can be avoided, so that the leakage protection device is protected.

Drawings

Embodiments are shown and described with reference to the drawings. These drawings are provided to illustrate the basic principles and thus only show the aspects necessary for understanding the basic principles. The figures are not to scale. In the drawings, like reference numerals designate similar features.

Fig. 1 is a schematic circuit diagram of a leakage protection device according to a first embodiment of the present invention;

fig. 2 is a schematic circuit diagram of a leakage protection device according to a second embodiment of the present invention;

FIG. 3 is a schematic circuit diagram of a leakage protection device according to a third embodiment of the present invention;

FIG. 4 is a schematic circuit diagram of a leakage protection device according to a fourth embodiment of the present invention;

FIG. 5 is a schematic circuit diagram of a leakage protection device according to a fifth embodiment of the present invention;

Detailed Description

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof. The accompanying drawings illustrate, by way of example, specific embodiments in which the utility model may be practiced. The illustrated embodiments are not intended to be exhaustive of all embodiments according to the utility model. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

As used herein, the terms "include," "include," and similar terms are to be construed as open-ended terms, i.e., "including/including but not limited to," meaning that additional content can be included as well. The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment," and the like.

The operation of the earth leakage protection device of the present invention is described in detail below with reference to fig. 1 to 5.

Fig. 1 is a schematic circuit diagram of a leakage protection device according to a first embodiment of the present invention. As shown in fig. 1, the earth leakage protection device includes a switch module 10, a delay trigger unit 11, a first driving unit 12, a reset switch 14, an earth leakage detecting unit 21, and a second driving unit 22. The leakage detecting unit 21 is configured to detect whether a leakage fault signal exists at a load end of the power supply line, the switch module 10 is configured to control a power connection between an input end (i.e., a power input end) of the power supply line and the load end, the first driving unit 12 includes a first transistor and a reset module, the first transistor is coupled to the reset module, the delay triggering unit 11 is coupled to the input end of the power supply line, the first driving unit 12 and the reset switch 14, and the delay triggering unit 11 is configured to turn on the first transistor of the first driving unit 12 after a predetermined time (e.g., 2 to 3 seconds) elapses after the input end of the leakage protection device is powered on or the reset switch 14 resets the main circuit, so as to turn on the reset module, and further turn on the power connection between the input end of the power supply line and the load end by the switch module 10. The second driving unit 22 includes a second transistor coupled to the trip module, and the trip module is configured to drive the second transistor to be turned on in response to the leakage detecting unit 21 detecting that the leakage fault signal exists at the load end of the power supply line, so that the trip module is powered on, and the switching module 10 is further caused to disconnect the power connection between the input end and the load end of the power supply line.

Specifically, as shown in fig. 1, the delay trigger unit 11 includes a diode D1 (i.e., a rectifying unit), a resistor R2 (i.e., a first resistor), a capacitor C4 (i.e., a first capacitor), a thyristor Q4 (i.e., a third transistor), a transistor Q3 (i.e., a fourth transistor), and a capacitor C2 (i.e., a second capacitor), the first driving unit 12 includes a thyristor Q1 (i.e., a first transistor) and a solenoid SOL1 (i.e., a reset module), the SOL1 is coupled to the switching module 10, a first end of the diode D1 is connected to a first power supply line (i.e., a first input terminal among input terminals of the power supply lines), a second end of the diode D1 is connected to a first end of a resistor R2, a second end of the resistor R2 is connected to a first end of the capacitor C4, a second end of the capacitor C4 is grounded (since the second power supply line (i.e., a second input terminal among input terminals of the power supply lines) is also grounded, which is equivalent to the second power supply line 4), a second terminal of resistor R2 is coupled to the first terminal of capacitor C2, and to the anode (i.e., the first pole) and gate (i.e., the second pole) of thyristor Q4, the cathode (i.e., the third pole) of thyristor Q4 is coupled to the second terminal of capacitor C4, the second terminal of capacitor C2 is coupled to the gate (i.e., the second pole) of thyristor Q1, the anode (i.e., the first pole) of thyristor Q1 is coupled to solenoid SOL1, the cathode (i.e., the third pole) of thyristor Q1 is coupled to the second terminal of capacitor C4, the collector (i.e., the first pole) and base (i.e., the second pole) of transistor Q3 are coupled to the first terminal of capacitor C2 and the anode of thyristor Q4, respectively, and the emitter (i.e., the third pole) of transistor Q3 is coupled to the second terminal of capacitor C4. The leakage detecting unit 21 includes a leakage detecting coil CT1 and a processor U1, the leakage detecting coil CT1 is coupled to the processor U1, a cathode (i.e., a third pole) and a gate (i.e., a second pole) of a thyristor Q2 (i.e., a second transistor) are coupled to the processor U1, an anode (i.e., a first pole) of the thyristor Q2 is coupled to a solenoid SOL2 (i.e., a trip module), and the SOL2 is coupled to the switch module 10. It should be understood that in one embodiment, the first supply line is an L line and the second supply line is an N line; in another embodiment, the first supply line is an N line and the second supply line is an L line.

The operation principle of the earth leakage protection device in fig. 1 is as follows:

the current of the main circuit is rectified by D1 and then charges a capacitor C4 through R2, after a first time, the voltage at the upper end (namely the first end) of C4 is increased to enable Q3 to be conducted, the electric quantity in C2 is released, the Q1 is in a cut-off state, the voltage at the upper end of C4 continues to be increased, after a second time, the voltage at the upper end of C4 is increased to be enough to enable the voltage at the upper end of R9 to trigger Q4 to be conducted after R6 and R9 divide voltage, Q3 is cut off after Q4 is conducted, then Q4 keeps in a conducting state, the current charges C2 through D1-R2-R3, Q1 is conducted, and then the current passes through SOL1, so that the switch module 10 of the leakage protection device is driven to be closed to connect the power connection between the input end of a power supply line and a load end. When C2 is fully charged, Q1 is turned off. After the earth leakage protection device trips due to a fault to turn off the switch module 10 (for example, when the earth leakage detection coil CT1 detects that there is earth leakage current between the input end and the load end of the power supply line (i.e., there is an earth leakage fault signal), the processor U1 is made to send out a driving signal to drive the thyristor Q2 to be on, so that the SOL2 is powered on, and thus the switch module 10 is turned off), the reset switch 14 is pressed to release the electric quantity in the C4, so that the above process of driving the switch module 10 to be closed is repeated. The implementation of the first embodiment shown in fig. 1 can prolong the time for which the switch module is closed after the input terminal of the earth leakage protection device is powered on or the reset switch is reset (for example, prolong a predetermined time (for example, 2 to 3 seconds) formed by the first time and the second time, and it should be understood that the length of the predetermined time can be adjusted by setting R2 and C4), so as to avoid the safety hazard caused by serious heating of the coil due to frequent driving of the solenoid coil, thereby protecting the earth leakage protection device.

The circuit configuration of the earth leakage protection device of the second embodiment as shown in fig. 2 is similar to that of the earth leakage protection device of the first embodiment as shown in fig. 1, except that the thyristor Q4 in fig. 1 is replaced by a transistor Q4.

The operation principle of the earth leakage protection device in fig. 2 is similar to that of the earth leakage protection device in fig. 1, and thus the detailed description thereof is omitted.

The circuit structure of the leakage protection device of the third embodiment shown in fig. 3 is similar to the circuit structure of the leakage protection device of the first embodiment shown in fig. 1, except that the delay triggering unit 130 of the leakage protection device of the third embodiment shown in fig. 3 further includes voltage dividing resistors R8 and R12 and a zener diode ZD1, wherein the voltage dividing resistors R8, R12 and R5 jointly divide the voltage to make Q3 conduct, and the zener diode ZD1 further reduces the voltage after R6 and R9 complete voltage reduction to trigger Q4 to conduct. In addition, the earth leakage protection device in the third embodiment of fig. 3 further includes a ground fault detection unit including a ground fault detection coil CT 2.

The operation principle of the earth leakage protection device in fig. 3 is as follows:

the current of the main circuit is rectified by D1 and then charges a capacitor C4 through R2, after a first time, the voltage at the upper end (namely the first end) of C4 is divided by R5, R8 and R12 to drive Q3 to be on, the electric quantity in C2 is released, so that Q1 is in an off state, then the voltage at the upper end of C4 continues to rise, after a second time, the voltage at the upper end of C4 rises to be enough to trigger Q4 to be on after R6 and R9 divide voltage and ZD1 reduces voltage, Q3 is off after Q4 is on, Q4 keeps an on state, the current charges C2 through D1-R2-R3 to enable Q1 to be on, so that SOL1 is electrified to drive a switch module 10 of the leakage protection device to be closed, and after C2 is electrified, the controllable silicon Q1 is off. As in the embodiment shown in fig. 1, the earth leakage protection device trips to open the switch module 10 due to a fault (for example, when the earth leakage detection coil CT1 detects that there is an earth leakage current between the input end of the power supply line and the load end (i.e., there is an earth leakage fault signal) or the earth fault detection coil CT2 detects that there is an earth fault signal, the processor U1 sends out a driving signal to drive the thyristor Q2 to conduct, so that the SOL2 is electrified, so that the switch module 10 is opened), and then the reset switch 14 is pressed to release the electric quantity in the C4, so that the above process of driving the switch module 10 to close is repeated.

The circuit structure of the leakage protection device of the fourth embodiment shown in fig. 4 is similar to that of the first embodiment shown in fig. 1, except that the delay trigger unit 140 of fig. 4 does not include the transistor Q3, and the cathode (i.e., the third pole) of the thyristor Q4 is coupled to the first end of the capacitor C2.

The operation principle of the earth leakage protection device in fig. 4 is as follows:

the main circuit current is rectified by D1 and then charges a capacitor C4 through R2, after a first time, the voltage at the upper end (namely the first end) of C4 is increased to be enough to be divided by R6 and R9, so that the voltage at the upper end of R9 can trigger Q4 to be switched on, after the Q4 is switched on, the current charges C2 through D1-R2-R3-Q4, Q1 is switched on, further SOL1 is electrified, the switch module 10 of the earth leakage protection device is switched on, and after C2 is fully charged, the thyristor Q1 is switched off. When the leakage protection device trips due to a fault to turn off the switch module 10 (for example, when the leakage detection coil CT1 detects that a leakage current exists between the input end and the load end of the power supply line (i.e., a leakage fault signal exists), the processor U1 drives the thyristor Q2 to be on, so that the SOL2 is energized, and the switch module 10 is turned off), and the reset switch 14 is pressed to release the electric quantity in the C4, so that the above process of driving the switch module 10 to be turned on is repeated.

The circuit configuration of the earth leakage protection device of the fifth embodiment shown in fig. 5 is similar to that of the earth leakage protection device of the first embodiment shown in fig. 1, except that the earth leakage protection device of fig. 5 employs a full bridge circuit DB instead of the diode D1 in fig. 1 for rectification, the input terminal of the full bridge circuit DB is coupled to the input terminal of the power supply line, and the output terminal of the full bridge circuit DB is coupled to the resistor R2 and the first terminal and the second terminal of the capacitor C4.

The operation principle of the leakage protection device in fig. 5 is the same as that of the leakage protection device in fig. 1, and is not described herein again.

It should be understood that the first transistor, the second transistor, the third transistor, and the fourth transistor in this document may be MOS transistors, triodes, thyristors, or other controllable switching devices. It should also be understood that the rectifying units in fig. 1 to 4 may be full bridge circuits, diodes, or other suitable units for rectifying. It should also be understood that the reset module and trip module may be other electromagnetic devices besides solenoids.

Thus, while the present invention has been described with reference to specific examples, which are intended to be illustrative only and not to be limiting of the utility model, it will be apparent to those of ordinary skill in the art that changes, additions or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the utility model.

Claims

1. An earth leakage protection device, characterized in that it comprises:

the leakage detection unit is used for detecting whether a leakage fault signal exists at the load end of the power supply line;

a switching module for controlling the electrical connection between the input end of the power supply line and the load end;

a first driving unit including a first transistor and a reset module, the first transistor being coupled with the reset module;

a reset switch;

a delay trigger unit coupled to the input terminal of the power supply line, the first driving unit, and the reset switch, wherein the delay trigger unit is configured to turn on the first transistor of the first driving unit after a predetermined time elapses after the input terminal of the earth leakage protection device is powered on or the reset switch resets the main circuit, so that the reset module is powered on, and the switch module is further connected to the power connection; and

a second driving unit including a second transistor and a trip module, the second transistor being coupled with the trip module, the second driving unit being configured to drive the second transistor to conduct in response to the leakage detecting unit detecting the presence of the leakage fault signal, thereby causing the trip module to conduct, thereby causing the switching module to disconnect the power connection.

2. The leakage protection device of claim 1, wherein the delay trigger unit comprises a rectifying unit, a first resistor, a first capacitor, a second capacitor, a third transistor and a fourth transistor, a first end of the rectifying unit is coupled to a first input terminal of the input terminals of the power supply line and a second end of the rectifying unit is coupled to a first end of the first resistor, a second end of the first resistor is coupled to a first end of the first capacitor and a second end of the first capacitor is coupled to a second input terminal of the input terminals of the power supply line, a second end of the first resistor is further coupled to a first end of the second capacitor, a first pole of the first transistor is coupled to the reset module, a second pole and a third pole of the first transistor are coupled to a second end of the second capacitor and a second end of the first capacitor, respectively, the first pole and the second pole of the third transistor are coupled to the first end of the first capacitor, the third pole of the third transistor is coupled to the second end of the first capacitor, the first pole and the second pole of the fourth transistor are coupled to the first end of the second capacitor and the first pole of the third transistor respectively, the third pole of the fourth transistor is coupled to the second end of the first capacitor, and the reset switch is coupled to two ends of the first capacitor.

3. The leakage protection device of claim 1, wherein the delay trigger unit comprises a rectifying unit, a first resistor, a first capacitor, a second capacitor and a third transistor, a first end of the rectifying unit is coupled to a first input terminal of the input terminals of the power supply line and a second end of the rectifying unit is coupled to a first end of the first resistor, a second end of the first resistor is coupled to a first end of the first capacitor, a first pole and a second pole of the third transistor are coupled to a first end of the first capacitor, a third pole of the third transistor is coupled to a first end of the second capacitor, a first pole and a second pole of the first transistor are coupled to the reset module and a second end of the second capacitor, respectively, a third pole of the first transistor is coupled to a second end of the first capacitor, the second end of the first capacitor is coupled to a second one of the input terminals of the supply line, and the reset switch is coupled across the first capacitor.

4. A residual current device according to claim 2 or 3, characterized in that said rectifying unit is a diode.

5. The earth leakage protection device of claim 2 or 3, wherein the rectifying unit is a full-bridge rectifying circuit, an input terminal of the full-bridge rectifying circuit is coupled to the input terminal of the power supply line, and an output terminal of the full-bridge rectifying circuit is coupled to the first terminal of the first resistor and the second terminal of the first capacitor.

6. The residual current device as claimed in claim 1, further comprising a ground fault detection unit coupled to said second driving unit, said second driving unit further configured to drive said second transistor to conduct in response to said ground fault detection unit detecting the presence of a ground fault signal, thereby energizing said trip module and causing said switch module to disconnect said power connection.

7. The leakage protection device of claim 2, wherein the first transistor, the second transistor, the third transistor, and the fourth transistor are selected from any one of: MOS pipe, silicon controlled rectifier and triode.

8. A leakage protection device according to claim 3, characterized in that the first transistor, the second transistor and the third transistor are selected from any of the following: MOS pipe, silicon controlled rectifier and triode.

9. A residual current device according to claim 1, characterized in that said reset module and said trip module each comprise an electromagnetic device.

10. A residual current device according to claim 9, characterized in that said electromagnetic means are solenoids.