Power line leakage current detection protection device and electric appliance

Abstract

The utility model discloses a power line leakage current detection protection device and an electric appliance. The power line leakage current detection protection device comprises a switch unit, an electric leakage detection unit, an electric leakage trigger unit, an electric leakage protection unit and an electric leakage indicating lamp unit. The electric leakage protection unit is respectively connected with the electric leakage trigger unit and the switch unit and is used for sending a corresponding control signal to the switch unit according to the electric leakage signal; and the electric leakage indicating lamp unit is used for lighting and alarming during electric leakage. According to the utility model, the leakage current on the power line can be detected in real time, and once the leakage current exceeds a safety threshold, the power supply can be quickly cut off through the electric leakage trigger unit and the electric leakage protection unit, so that the occurrence of potential safety hazards such as electrical fire and electric shock accidents is prevented, and the electricity utilization safety is improved; the electric leakage detection unit is arranged on the power line in a surrounding mode, all-around monitoring is achieved, leakage current is amplified through the electric leakage trigger unit, even very small leakage current can be detected and responded, and the response can be achieved within a safety standard value.

Description

Technical Field

[0001] The utility model belongs to the technical field of electricity, and particularly relates to a power line leakage current detection and protection device and an electrical appliance. Background Art

[0002] The power line leakage current detection and protection device is abbreviated as PRCD leakage protector. Its main structure is a power line with a plug. Its main function is to detect the leakage current between the live wire, neutral wire, etc. of the power line from the power supply plug to the load electrical appliance such as an air conditioner or a dehumidifier and the shielding of the wire protective layer, cut off the power supply of the electrical equipment, prevent the occurrence of fire, and provide safety protection. Prevent arc fault fires caused by damage to the power line and a decrease in insulation strength due to aging, wear, extrusion, or animal gnawing of the live wire, neutral wire, and ground wire in the power line.

[0003] Therefore, there is an urgent need for a power line leakage current detection and protection device that can detect the leakage detection line. Summary of the Utility Model

[0004] In view of this, the main purpose of the utility model is to provide a power line leakage current detection and protection device and an electrical appliance.

[0005] To achieve the above object, the technical solution of the utility model is realized as follows:

[0006] An embodiment of the utility model provides a power line leakage current detection and protection device, including

[0007] A switch unit, arranged between the input end and the output end, for controlling the energization or de-energization of the input end and the output end;

[0008] A leakage detection unit, arranged around the power line connected between the switch unit and the input end, for detecting whether there is leakage current on the power line;

[0009] A leakage trigger unit, for obtaining the leakage information of the leakage detection unit and controlling the leakage protection unit to control the switch unit to close;

[0010] A leakage protection unit, respectively connected to the leakage trigger unit and the switch unit, for sending corresponding control signals to the switch unit according to the leakage signal;

[0011] A leakage indicator unit, for giving an alarm prompt during leakage.

[0012] In the above solution, the switch unit includes a first switch and a varistor, and the first switch and the varistor voltage are respectively connected to the live wire and the neutral wire of the power line.

[0013] In the above solution, the leakage detection unit includes a zero-sequence detector, a second resistor, a third resistor, a fourth resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, and a bidirectional diode. The zero-sequence detector is disposed around the power line. The first end of the second resistor is connected to the first end of the zero-sequence detector, the first end of the bidirectional diode, the second end of the bidirectional diode, and the first end of the third resistor. The second end of the second resistor is connected to the second end of the zero-sequence detector, the third end of the bidirectional diode D7, the fourth end of the bidirectional diode, and the first end of the fourth resistor. The second end of the third resistor is connected to the first end of the sixth resistor and the first end of the seventh capacitor. The second end of the sixth capacitor is connected to the second end of the fourth resistor and the first end of the eighth capacitor. The second end of the seventh capacitor is connected to the second end of the eighth capacitor and then grounded.

[0014] In the above solution, the leakage protection unit includes a trip coil, a seventh resistor, a tenth resistor, an eleventh resistor, a ninth capacitor, a second diode, a third diode, a fourth diode, and a fifth diode. The first end of the seventh resistor is connected to the live wire of the power line. The second end of the seventh resistor is connected to the first end of the ninth capacitor and the first end of the eleventh resistor. The second end of the eleventh resistor is connected in series with the tenth resistor and then connected to the second end of the ninth capacitor, the positive electrode of the third diode, and the negative electrode of the fifth diode. The positive electrode of the fifth diode is connected to the positive electrode of the fourth diode and then grounded. The negative electrode of the fourth diode is connected to the neutral wire of the power line and the positive electrode of the second diode. The negative electrode of the second diode is connected to the negative electrode of the third diode and the first end of the trip coil. The second end of the trip coil is grounded. The control end of the trip coil is connected to the first switch.

[0015] In the above solution, the leakage trigger unit includes a leakage detection chip, a first diode, a first resistor, a sixth resistor, an eighth resistor, a ninth resistor, a fifteenth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a tenth capacitor, a transistor, and a sixth diode. The positive electrode of the first diode is connected to the live wire of the power supply line. The negative electrode of the first diode is successively connected in series with the first resistor and the eighth resistor and then respectively connected to the eighth terminal of the leakage detection chip, the first terminal of the third capacitor, and the negative electrode of the sixth diode. The seventh terminal of the leakage detection chip is connected in series with the ninth resistor and then respectively connected to the first terminal of the fifteenth resistor, the first terminal of the second capacitor, and the base of the transistor. The emitter of the transistor is connected in series with the sixth resistor and then respectively connected to the first terminal of the first capacitor, the first terminal of the tenth capacitor, and the first terminal of the trip coil. The first terminal of the leakage detection chip is connected to the second terminal of the fourth resistor. The second terminal of the leakage detection chip is connected to the second terminal of the third resistor. The fifth terminal of the leakage detection chip is connected to the first terminal of the fifth capacitor. The sixth terminal of the leakage detection chip is connected to the first terminal of the fourth capacitor. The second terminals of the first capacitor, the tenth capacitor, the third terminal of the leakage detection chip, the second terminal of the fifth capacitor, the second terminal of the fourth capacitor, the second terminal of the fifteenth resistor, the second terminal of the second capacitor, the collector of the transistor, the second terminal of the third capacitor, and the positive electrode of the sixth diode are all grounded.

[0016] In the above solution, the leakage indicator unit includes a second switch, a fourteenth resistor, a fifth resistor, an eighth diode, a twelfth resistor, a leakage indicator, and a thirteenth resistor. The first terminal of the second switch is connected to the neutral wire of the power supply line. The second terminal of the second switch is successively connected in series with the fourteenth resistor and the fifth resistor and then respectively connected to the positive electrode of the eighth diode and the live wire of the power supply line. The negative electrode of the eighth diode is successively connected in series with the twelfth resistor, the leakage indicator, and the thirteenth resistor and then connected to the neutral wire of the power supply line.

[0017] Embodiment 2 of the present utility model provides an electrical appliance with a power supply line leakage current detection and protection device, including: the power supply line leakage current detection and protection device as described above.

[0018] Compared with the prior art, the utility model can detect the leakage current on the power line in real time. Once it is found that the leakage current exceeds the safety threshold, the switch unit can be quickly controlled to disconnect through the leakage trigger unit and the leakage protection unit, thus effectively preventing safety hazards such as electrical fires and electric shock accidents, and greatly improving the safety of the power consumption environment; by arranging the leakage detection unit around the power line, it can achieve all-round monitoring, and combined with the leakage trigger unit to amplify the leakage current, making the detection result more accurate. Even very small leakage currents can be detected and responded to in a timely manner, and it can also respond when the leakage current is within the safety specification value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to disclose a further understanding of the utility model and form a part of the utility model. The schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an improper limitation to the utility model. In the drawings:

[0020] Figure 1 It is a schematic structural diagram of a power line leakage current detection and protection device according to an embodiment of the utility model.

[0021] Figure 2 It is a schematic structural diagram of an electrical appliance with a power line leakage current detection and protection device according to an embodiment of the utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to make the purpose, technical solutions and advantages of the utility model clearer, the following further details the utility model with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model.

[0023] In the drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the utility model, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation to this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0024] It should be noted that in this text, the term "comprise", "include" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, article or device comprising that element.

[0025] As Figure 1 shown, Embodiment 1 of the present utility model provides a power cord leakage current detection and protection device, comprising

[0026] a switch unit, arranged between the input end and the output end, for controlling the power-on or power-off of the input end and the output end;

[0027] a leakage detection unit, arranged around the power cord connected between the switch unit and the input end, for detecting whether there is leakage current on the power cord;

[0028] a leakage trigger unit, for obtaining the leakage information of the leakage detection unit and controlling the leakage protection unit to control the switch unit to close;

[0029] a leakage protection unit, respectively connected to the leakage trigger unit and the switch unit, for sending a corresponding control signal to the switch unit according to the leakage signal;

[0030] a leakage indicator unit, for giving an alarm prompt during leakage.

[0031] As Figure 1 shown, the switch unit includes a first switch S1 and a varistor MOV, and the first switch S1 and the varistor MOV are respectively connected to the live wire L_IN and the neutral wire N_IN of the power cord.

[0032] As Figure 1As shown, the leakage detection unit includes a zero-sequence detector T1, a second resistor R2, a third resistor R3, a fourth resistor R4, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, and a bidirectional diode D7. The zero-sequence detector T1 is wound around the power line. The first end of the second resistor R2 is connected to the first end of the zero-sequence detector T1, the first end of the bidirectional diode D7, the second end of the bidirectional diode D7, and the first end of the third resistor R3. The second end of the second resistor R2 is connected to the second end of the zero-sequence detector T1, the third end of the bidirectional diode D7, the fourth end of the bidirectional diode D7, and the first end of the fourth resistor R4. The second end of the third resistor R3 is connected to the first end of the sixth capacitor C6 and the first end of the seventh capacitor C7. The second end of the sixth capacitor C6 is connected to the second end of the fourth resistor R4 and the first end of the eighth capacitor C8. The second end of the seventh capacitor C7 is connected to the second end of the eighth capacitor C8 and then grounded.

[0033] As Figure 1 As shown, the leakage protection unit includes a tripping coil SOL, a seventh resistor R7, a tenth resistor R10, an eleventh resistor R11, a ninth capacitor R9, a second diode D2, a third diode D3, a fourth diode D4, and a fifth diode D5. The first end of the seventh resistor R7 is connected to the live wire L_IN of the power line. The second end of the seventh resistor R7 is connected to the first end of the ninth capacitor C9 and the first end of the eleventh resistor R11. The second end of the eleventh resistor R11 is connected in series with the tenth resistor R10 and then connected to the second end of the ninth capacitor C9, the positive electrode of the third diode D3, and the negative electrode of the fifth diode D5. The positive electrode of the fifth diode D5 is connected to the positive electrode of the fourth diode D4 and then grounded. The negative electrode of the fourth diode D4 is connected to the neutral wire N_IN of the power line and the positive electrode of the second diode D2. The negative electrode of the second diode D2 is connected to the negative electrode of the third diode D3 and the first end of the tripping coil SOL. The second end of the tripping coil SOL is grounded. The control end of the tripping coil SOL is connected to the first switch S1 for controlling the normally closed second switch S1 to trip and open.

[0034] As Figure 1As shown in the figure, the leakage trigger unit includes a leakage detection chip U1, a first diode D1, a first resistor R1, a sixth resistor R6, an eighth resistor R8, a ninth resistor R9, a fifteenth resistor R15, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a tenth capacitor C10, a transistor Q1, and a sixth diode D6. The positive electrode of the first diode D1 is connected to the live wire L_IN of the power supply line. The negative electrode of the first diode D1 is successively connected in series with the first resistor R1 and the eighth resistor R8 and then respectively connected to the eighth terminal of the leakage detection chip U1, the first terminal of the third capacitor C3, and the negative electrode of the sixth diode D6. The seventh terminal of the leakage detection chip U1 is connected in series with the ninth resistor R9 and then respectively connected to the first terminal of the fifteenth resistor R15, the first terminal of the second capacitor C2, and the base of the transistor Q1. The emitter of the transistor Q1 is connected in series with the sixth resistor R6 and then respectively connected to the first terminal of the first capacitor C1, the first terminal of the tenth capacitor C10, and the first terminal of the trip coil SOL. The first terminal of the leakage detection chip U1 is connected to the second terminal of the fourth resistor R4. The second terminal of the leakage detection chip U1 is connected to the second terminal of the third resistor R3. The fifth terminal of the leakage detection chip U1 is connected to the first terminal of the fifth capacitor C5. The sixth terminal of the leakage detection chip U1 is connected to the first terminal of the fourth capacitor C4. The second terminals of the first capacitor C1, the tenth capacitor C10, the third terminal of the leakage detection chip U1, the second terminal of the fifth capacitor C5, the second terminal of the fourth capacitor C4, the second terminal of the fifteenth resistor R15, the second terminal of the second capacitor C2, the collector of the transistor Q1, the second terminal of the third capacitor C3, and the positive electrode of the sixth diode D6 are all grounded.

[0035] As Figure 1 shown in the figure, the leakage indicator unit includes a second switch S2, a fourteenth resistor R14, a fifth resistor R5, an eighth diode D8, a twelfth resistor R12, a leakage indicator LED, and a thirteenth resistor R13. The first terminal of the second switch S2 is connected to the neutral wire N_IN of the power supply line. The second terminal of the second switch S2 is successively connected in series with the fourteenth resistor R14 and the fifth resistor R5 and then respectively connected to the positive electrode of the eighth diode D8 and the live wire L_IN of the power supply line. The negative electrode of the eighth diode D8 is successively connected in series with the twelfth resistor R12, the leakage indicator LED, and the thirteenth resistor R13 and then connected to the neutral wire N_IN of the power supply line.

[0036] Embodiment 2 of the present invention provides an electrical appliance with a power supply line leakage current detection and protection device, including: the power supply line leakage current detection and protection device as described above.

[0037] As Figure 2As shown in the figure, the present utility model relates to a power line leakage current detection and protection device, the core of which lies in integrating multiple functional units to effectively detect and protect the leakage current on the power line.

[0038] The working principle of the present utility model is elaborated in detail as follows:

[0039] Switch unit:

[0040] The switch unit consists of a first switch S1 and a metal oxide varistor MOV, which are respectively connected to the live wire L_IN and the neutral wire N_IN of the power line. This unit is used to control the on or off state between the input end and the output end.

[0041] Leakage detection unit:

[0042] The leakage detection unit is arranged around the power line through a zero-sequence detector T1, and is used to monitor in real time whether there is leakage current on the power line. This unit also includes multiple resistors, capacitors and bidirectional diodes, forming a complex detection circuit that can accurately capture and analyze the leakage current signal.

[0043] Leakage trigger unit:

[0044] The leakage trigger unit obtains the output signal of the leakage detection unit and amplifies it through a leakage detection chip U1. Once a leakage signal is detected, this unit will trigger the leakage protection unit.

[0045] Leakage protection unit:

[0046] The leakage protection unit receives the signal from the leakage trigger unit and sends a corresponding control signal to the switch unit according to the signal strength. In case of leakage, the trip coil SOL will be activated, causing the first switch S1 to trip and disconnect, thereby cutting off the power supply and protecting the circuit and equipment from damage.

[0047] Leakage indicator unit:

[0048] When leakage is detected, the leakage indicator LED of the leakage indicator unit goes out, giving a visual alarm to remind the user of the leakage risk.

[0049] In summary, the present utility model realizes the comprehensive detection and protection of the leakage current on the power line by integrating the switch unit, the leakage detection unit, the leakage trigger unit, the leakage protection unit and the leakage indicator unit. When leakage is detected, the present utility model can quickly cut off the power supply and give an alarm through the indicator light, effectively protecting the safety of users and equipment.

[0050] The above description is only a preferred embodiment of the present utility model and is not intended to limit the protection scope of the present utility model.

Claims

1. A power cord leakage current detection and protection device, characterized in that Including a switch unit, arranged between the input end and the output end, for controlling the energization or de-energization of the input end and the output end; a leakage detection unit, arranged around the power line connected between the switch unit and the input end, for detecting whether there is a leakage current on the power line; a leakage trigger unit, for obtaining the leakage information of the leakage detection unit and controlling the leakage protection unit to control the switch unit to close; a leakage protection unit, respectively connected to the leakage trigger unit and the switch unit, for sending a corresponding control signal to the switch unit according to the leakage signal; a leakage indicator unit, for giving an alarm prompt during leakage.

2. The power line leakage current detection and protection device according to claim 1, wherein The switch unit includes a first switch and a varistor, and the first switch and the varistor voltage are respectively connected to the live wire and the neutral wire of the power line.

3. The power line leakage current detection and protection device according to claim 2, characterized in that, The leakage detection unit includes a zero-sequence detector, a second resistor, a third resistor, a fourth resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, and a bidirectional diode. The zero-sequence detector is arranged around the power line. The first end of the second resistor is respectively connected to the first end of the zero-sequence detector, the first end of the bidirectional diode, the second end of the bidirectional diode, and the first end of the third resistor. The second end of the second resistor is respectively connected to the second end of the zero-sequence detector, the third end of the bidirectional diode, the fourth end of the bidirectional diode, and the first end of the fourth resistor. The second end of the third resistor is respectively connected to the first end of the sixth capacitor and the first end of the seventh capacitor. The second end of the sixth capacitor is respectively connected to the second end of the fourth resistor and the first end of the eighth capacitor. The second end of the seventh capacitor is connected to the second end of the eighth capacitor and then grounded.

4. The power cord leakage current detection and protection device according to claim 3, characterized in that, The leakage protection unit includes a trip coil, a seventh resistor, a tenth resistor, an eleventh resistor, a ninth capacitor, a second diode, a third diode, a fourth diode, and a fifth diode. The first end of the seventh resistor is connected to the live wire of the power line. The second end of the seventh resistor is respectively connected to the first end of the ninth capacitor and the first end of the eleventh resistor. The second end of the eleventh resistor is connected in series with the tenth resistor and then respectively connected to the second end of the ninth capacitor, the positive electrode of the third diode, and the negative electrode of the fifth diode. The positive electrode of the fifth diode is connected to the positive electrode of the fourth diode and then grounded. The negative electrode of the fourth diode is respectively connected to the neutral wire of the power line and the positive electrode of the second diode. The negative electrode of the second diode is respectively connected to the negative electrode of the third diode and the first end of the trip coil. The second end of the trip coil is grounded, and the control end of the trip coil is connected to the first switch.

5. The power cord leakage current detection and protection device according to claim 4, characterized in that The leakage trigger unit includes a leakage detection chip, a first diode, a first resistor, a sixth resistor, an eighth resistor, a ninth resistor, a fifteenth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a tenth capacitor, a transistor, and a sixth diode. The positive electrode of the first diode is connected to the live wire of the power supply line. The negative electrode of the first diode is sequentially connected in series with the first resistor and the eighth resistor and then respectively connected to the eighth terminal of the leakage detection chip, the first terminal of the third capacitor, and the negative electrode of the sixth diode. The seventh terminal of the leakage detection chip is connected in series with the ninth resistor and then respectively connected to the first terminal of the fifteenth resistor, the first terminal of the second capacitor, and the base control electrode of the transistor. The emitter anode of the transistor is connected in series with the sixth resistor and then respectively connected to the first terminal of the first capacitor, the first terminal of the tenth capacitor, and the first terminal of the trip coil. The first terminal of the leakage detection chip is connected to the second terminal of the fourth resistor. The second terminal of the leakage detection chip is connected to the second terminal of the third resistor. The fifth terminal of the leakage detection chip is connected to the first terminal of the fifth capacitor. The sixth terminal of the leakage detection chip is connected to the first terminal of the fourth capacitor. The second terminals of the first capacitor, the tenth capacitor, the third terminal of the leakage detection chip, the second terminal of the fifth capacitor, the second terminal of the fourth capacitor, the second terminal of the fifteenth resistor, the second terminal of the second capacitor, the collector of the transistor, the second terminal of the third capacitor, and the positive electrode of the sixth diode are all grounded.

6. The power cord leakage current detection and protection device according to claim 5, wherein, The leakage indicator unit includes a second switch, a fourteenth resistor, a fifth resistor, an eighth diode, a twelfth resistor, a leakage indicator, and a thirteenth resistor. The first terminal of the second switch is connected to the neutral wire of the power supply line. The second terminal of the second switch is sequentially connected in series with the fourteenth resistor and the fifth resistor and then respectively connected to the positive electrode of the eighth diode and the live wire of the power supply line. The negative electrode of the eighth diode is sequentially connected in series with the twelfth resistor, the leakage indicator, and the thirteenth resistor and then connected to the neutral wire of the power supply line.

7. An electrical appliance with a power cord leakage current detection and protection device, characterized in that, Comprising: The power supply line leakage current detection and protection device according to any one of claims 1 to 6.

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