Leakage protection self-checking equipment based on rectification multiplexing

Abstract

The invention belongs to the technical field of electric leakage protection, and discloses electric leakage protection self-checking equipment based on rectification multiplexing, which comprises a first mutual inductance module, a second mutual inductance module, a self-checking module, an electric leakage detection module and a tripping module, the electric leakage detection module comprises a rectification power supply unit, an electric leakage detection unit and a control unit. The first mutual inductance module is connected with the electric leakage detection unit; the second mutual inductance module is respectively connected with the self-checking module and the ground; the self-checking module is connected with the rectification power supply unit and the control unit. The rectification power supply unit is connected with the power line and the leakage detection unit. The rectification power supply unit is used for rectifying a power signal of a power line and then sending the rectified power signal to the electric leakage detection unit and the self-checking module. The area and the cost of the self-checking module can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of leakage protection, in particular to a leakage protection self-checking device based on rectification reuse. BACKGROUND

[0002] In order to protect equipment and personal safety, leakage protection has become an indispensable auxiliary device in production and life, and plays a crucial role in electrical systems, which can quickly cut off the circuit when leakage failure occurs. However, in the long-term operation of the existing leakage protection switch or leakage protection plug, the leakage protection circuit itself may have problems such as component aging and performance degradation, thereby burying safety hazards. Therefore, a self-checking module is added in the leakage protection device to periodically simulate the leakage signal generated by the power grid to ground to realize periodic detection of whether the leakage protection device can work normally.

[0003] The traditional self-checking module in the leakage protection device is usually realized by a separate circuit, which usually includes a signal sampling rectification circuit structure and a current sampling power resistor, resulting in multiple devices, high cost and large area of the entire leakage protection product. SUMMARY

[0004] The present application provides a leakage protection self-checking device based on rectification reuse, which can reduce the area and cost of the self-checking module.

[0005] The present application provides a leakage protection self-checking device based on rectification reuse, which can reduce the area and cost of the self-checking module.

[0006] The leakage detection module includes a rectification power supply unit, a leakage detection unit and a control unit; the first mutual inductance module is connected to the leakage detection unit; and the second mutual inductance module is connected to the self-checking module and the ground, respectively.

[0007] The self-checking module is connected to the rectification power supply unit and the control unit, respectively.

[0008] The rectification power supply unit is connected to the power supply line and the leakage detection unit, respectively; and the rectification power supply unit is used to rectify the power supply signal of the power supply line and send it to the leakage detection unit and the self-checking module, respectively.

[0009] The leakage detection unit is used to process the leakage signal of the first mutual inductance module and send it to the control unit.

[0010] The control unit is used to determine whether the processed leakage signal exceeds a preset trip threshold, and if so, sends a trip signal to the trip module; and sends a self-checking start signal to the self-checking module according to a preset period; receives the self-checking current signal of the self-checking module and determines whether it exceeds the preset trip threshold, and if so, sends a trip signal to the trip module.

[0011] The self-checking module is configured to, in response to a self-checking start signal, connect the rectifier power supply unit and the second mutual inductance module, and send a self-checking current signal in the connected link to the control unit;

[0012] The tripping module is configured to perform a tripping operation after receiving a tripping signal.

[0013] Further, the first mutual inductance module and the second mutual inductance module are both coils and are wound on the same iron ring.

[0014] Further, the self-checking module includes a self-checking switch unit and a sampling resistance unit connected to each other;

[0015] The self-checking switch unit is connected to the second mutual inductance module and the control unit, respectively;

[0016] The sampling resistance unit is connected to the control unit and the rectifier power supply unit, respectively;

[0017] The self-checking switch unit is configured to, after receiving a self-checking start signal from the control unit, close the switch to connect the second mutual inductance module, the sampling resistance unit and the rectifier power supply unit;

[0018] The sampling resistance unit is configured to send the sampled self-checking current signal to the control unit.

[0019] Further, the self-checking module further includes a self-checking power supply unit; the self-checking power supply unit is connected to the control unit;

[0020] The self-checking power supply unit is configured to supply power to the control unit after the self-checking switch unit closes the switch.

[0021] Further, the self-checking module further includes a manual switch unit; the manual switch unit is connected in parallel with the self-checking switch unit; the manual switch unit is configured to receive a user instruction, close the switch to connect the second mutual inductance module, the sampling resistance unit and the rectifier power supply unit.

[0022] Further, the leakage detection unit is specifically configured to perform filtering and amplification processing on the leakage signal.

[0023] Further, the tripping module includes a tripping unit and a self-checking level unit;

[0024] The control unit is connected to the tripping unit and the self-checking level unit, respectively;

[0025] The control unit is configured to send a tripping signal to the tripping unit;

[0026] The tripping unit is configured to perform a tripping operation after receiving the tripping signal; the self-checking level unit is configured to collect a voltage signal of the tripping unit, generate a tripping result according to the voltage signal and send the tripping result to the control unit.

[0027] Further, the tripping unit comprises a tripping coil, a half-wave rectification unit and a thyristor connected in sequence;

[0028] The tripping coil is connected with a power line;

[0029] The thyristor is connected with the control unit, and is used for pulling down the anode voltage below a preset threshold in response to the trip signal;

[0030] The half-wave rectification unit is connected with the self-checking level unit; the half-wave rectification unit is used for collecting a voltage signal between the tripping coil and the thyristor, and sending the voltage signal to the self-checking level unit.

[0031] Further, the tripping module further comprises a voltage dividing resistor unit;

[0032] The voltage dividing resistor unit is connected with the self-checking level unit and the ground respectively.

[0033] Further, the number of turns of the first mutual inductance module is greater than or equal to the number of turns of the second mutual inductance module.

[0034] Compared with the prior art, the technical scheme provided by the embodiment of the present application has at least the following beneficial effects:

[0035] The self-checking device for the leakage protection provided by the embodiment of the present application connects the rectification power supply unit in the leakage detection module to the self-checking module, so as to realize the multiplexing of the rectification power supply unit. When the leakage protection self-checking is performed, the self-checking module can simulate the leakage signal generated by the power grid to the ground by connecting the rectification power supply unit and the second mutual inductance module connected with the ground at the other end. At this time, the original rectification circuit structure in the self-checking module can be removed, thereby reducing the area and cost of the self-checking module. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The structure diagram of the self-checking device for the leakage protection provided by the embodiment of the present application is shown.

[0037] Figure 2 The circuit principle diagram of the leakage protection device with self-checking in the prior art provided by the embodiment of the present application is shown.

[0038] Figure 3 The circuit principle diagram of the self-checking device for the leakage protection provided by the embodiment of the present application is shown.

[0039] Figure 4 The structure diagram of the self-checking device for the leakage protection provided by the embodiment of the present application is shown. DETAILED DESCRIPTION

[0040] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application.

[0041] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0042] Please refer to Figure 1 The embodiments of the present application provide a leakage protection self-checking device based on rectification multiplexing, comprising a first mutual inductance module, a second mutual inductance module, a self-checking module, a leakage detection module and a tripping module.

[0043] The leakage detection module comprises a rectification power supply unit, a leakage detection unit and a control unit; the first mutual inductance module is connected to the leakage detection unit; and the second mutual inductance module is connected to the self-checking module and the ground respectively.

[0044] The first mutual inductance module and the second mutual inductance module are both coils and are wound on the same iron ring.

[0045] Further, the number of turns of the first mutual inductance module can be greater than or equal to the number of turns of the second mutual inductance module.

[0046] The self-checking module is connected to the rectification power supply unit and the control unit respectively.

[0047] The rectification power supply unit is connected to the power line and the leakage detection unit respectively; and the rectification power supply unit is used to send the power signal of the power line to the leakage detection unit and the self-checking module after rectification. It should be noted that the power signal will pass through the self-checking module only after the self-checking module receives the self-checking start signal and is turned on.

[0048] The leakage detection unit is used to send the leakage signal of the first mutual inductance module to the control unit after processing.

[0049] The control unit is used to determine whether the processed leakage signal exceeds a preset tripping threshold, and if so, to send a tripping signal to the tripping module; and to send a self-checking start signal to the self-checking module according to a preset period; to receive a self-checking current signal from the self-checking module and determine whether it exceeds the preset tripping threshold, and if so, to send a tripping signal to the tripping module.

[0050] Specifically, the leakage detection unit is specifically used for filtering and amplifying the leakage signal.

[0051] In the implementation process, in the normal working state, the first mutual inductance module monitors the leakage signal in the circuit in real time; the first mutual inductance module can be a zero sequence current transformer, the transformer is sleeved on the power line of the protected circuit, when the circuit is normally operated, the vector sum of the phase currents is zero, and the secondary side of the zero sequence current transformer has no output, when the leakage fault occurs, the vector sum of the phase currents is not zero, and the secondary side of the zero sequence current transformer can induce the corresponding leakage signal.

[0052] The leakage detection unit processes the detected leakage signal, converts the weak leakage signal into a signal that can be effectively recognized and processed by the control unit, and the leakage detection unit can be composed of an operational amplifier and a filter circuit. The operational amplifier amplifies the leakage signal, and the filter circuit removes the noise interference in the signal, thereby improving the quality and stability of the signal.

[0053] The control unit determines whether the circuit needs to be cut off according to the processed signal; after receiving the leakage signal processed by the leakage detection unit, the control unit compares it with the preset tripping threshold value, and when the threshold value is exceeded, the control unit sends a trip signal.

[0054] The self-checking module is used to connect the rectifier power supply unit and the second mutual inductance module in response to a self-checking start signal, and send the self-checking current signal in the connected link to the control unit.

[0055] Specifically, as shown in Figure 1 When the self-checking module connects the rectifier power supply unit and the second mutual inductance module, due to the other end of the second mutual inductance module being grounded, one end of the rectifier power supply unit being connected to the power line, thereby forming a current path, so that part of the current in the power line, more specifically, the hot wire in the power line, flows to the ground through the path, causing the current vector sum of the hot wire and the zero wire in the power line to be not zero, so that the first mutual inductance module generates a leakage signal due to electromagnetic induction principle.

[0056] The tripping module is used to perform a tripping operation after receiving a trip signal.

[0057] The leakage protection self-checking device based on rectifier multiplexing provided by the above embodiment connects the rectifier power supply unit in the leakage detection module to the self-checking module to realize multiplexing of the rectifier power supply unit. When performing leakage protection self-checking, the self-checking module can simulate the leakage signal generated by the power grid to the ground by connecting the rectifier power supply unit and the second mutual inductance module with the other end grounded; at this time, the original rectifier circuit structure in the self-checking module can be removed, thereby reducing the area and cost of the self-checking module.

[0058] In some embodiments, the self-checking module includes a self-checking switch unit and a sampling resistance unit connected to each other.

[0059] The self-checking switch unit is connected to the second mutual inductance module and the control unit, respectively.

[0060] The sampling resistance unit is connected to the control unit and the rectifier power supply unit respectively.

[0061] The self-checking switch unit is used to close the switch to connect the second mutual inductance module, the sampling resistance unit and the rectifier power supply unit after receiving the self-checking start signal of the control unit.

[0062] The sampling resistance unit is used to send the self-checking current signal obtained by sampling to the control unit.

[0063] Specifically, by using the mutual inductor same scale principle, the turns of the second mutual inductance module can be adjusted to reduce the power of the sampling resistance. For example, 1 turn is equal to 1 times the leakage current of the sampling resistance (the input voltage of the power line divided by the resistance value of the sampling resistance), and 5 turns are equal to 5 times the original sampling current. In this way, the resistance value of the sampling resistance can be increased by 5 times, so that the power of the sampling resistance can be reduced to 1 / 5 of the original power, and low-power resistance detection can be realized.

[0064] In some embodiments, the self-checking module further comprises a self-checking power supply unit; the self-checking power supply unit is connected to the control unit.

[0065] The self-checking power supply unit is used to supply power to the control unit after the self-checking switch unit closes the switch.

[0066] Specifically, after the second mutual inductance module, the sampling resistance unit and the rectifier power supply unit are turned on, the self-checking switch unit and the second mutual inductance module will make the power signal output by the rectifier power supply unit flow to the ground, thereby causing the control unit to be insufficiently powered and unable to process the self-checking current signal. Therefore, the application adds a self-checking power supply unit to the self-checking module to ensure the normal operation of the control unit during the leakage self-checking process. It should be noted that because the rectifier power supply unit is provided with a circuit structure for rectifying the power signal, the area of the unit will be larger than that of the self-checking power supply unit, so that even after adding a self-checking power supply unit, the effect of reducing the area of the entire leakage protection device product can still be achieved.

[0067] In some embodiments, the self-checking module further comprises a manual switch unit.

[0068] The manual switch unit is connected in parallel with the self-checking switch unit; the manual switch unit is used to receive user instructions, close the switch to connect the second mutual inductance module, the sampling resistance unit and the rectifier power supply unit.

[0069] Specifically, please refer to Figure 2 and Figure 3The traditional manual self-checking module in the leakage protector is also a separate detection link, so if the leakage protector has both self-checking and manual self-checking, there will be three rectifier circuit structures, three mutual inductance modules and two sampling resistors, and the application connects the manual switch unit and the self-checking switch unit in parallel, thereby eliminating the rectifier circuit, the mutual inductance module and the sampling resistor in the original manual self-checking module, and multiplexing the rectifier, the mutual inductance module and the sampling resistor for manual self-checking and periodic self-checking, and also ensuring that the power line of the power grid is simulated for leakage when the manual switch unit is triggered.

[0070] Please refer to Figure 4 In some embodiments, the tripping module includes a tripping unit and a self-checking level unit.

[0071] The control unit is connected to the tripping unit and the self-checking level unit, respectively.

[0072] The control unit is configured to send a tripping signal to the tripping unit.

[0073] The tripping unit is configured to perform a tripping operation after receiving the tripping signal, and the self-checking level unit is configured to collect a voltage signal of the tripping unit, generate a tripping result according to the voltage signal and send the tripping result to the control unit.

[0074] Further, the control unit receives the tripping result after sending the tripping signal, and knows whether the self-checking is passed.

[0075] Specifically, the tripping unit includes a tripping coil, a half-wave rectifier unit and a thyristor connected in sequence; the tripping coil is connected to the power line; the thyristor is connected to the control unit and is configured to pull down an anode voltage to below a preset threshold in response to the tripping signal.

[0076] The half-wave rectifier unit is connected to the self-checking level unit; the half-wave rectifier unit is configured to collect a voltage signal between the tripping coil and the thyristor and send the voltage signal to the self-checking level unit.

[0077] Specifically, the control unit outputs a tripping signal to turn on the thyristor, the anode voltage is pulled down after the thyristor is turned on, and the control unit sends a level change to the control unit when the self-checking level unit monitors the level change. The control unit continuously monitors the level change of the positive and negative half cycles of the power grid, and sends a self-checking start signal at a timing, and further outputs a high-level trigger signal to turn on the thyristor if no level change is received after the self-checking start signal is sent. The thyristor generates a large current through the tripping coil to ground, and the large current generates a magnetic attraction through the tripping coil to trip.

[0078] In some embodiments, the tripping module further includes a voltage dividing resistor unit.

[0079] The voltage dividing resistor unit is connected to the self-checking level unit and the ground, respectively.

[0080] Specifically, in the case of leakage self-checking or real leakage, the control unit turns on the thyristor, so that the anode voltage of the thyristor is pulled down, but in this process, the more the voltage drops, the more the device on the line generates heat, and frequent self-checking is likely to cause a fire, therefore the application increases the voltage dividing resistor unit to share the voltage pulled down when the thyristor is turned on.

[0081] The technical features of the above embodiments can be combined in any manner. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0082] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims.

Claims

1. A leakage current protection self-test device based on rectification and multiplexing, characterized in that, It includes a first mutual inductance module, a second mutual inductance module, a self-test module, a leakage current detection module, and a tripping module; The leakage current detection module includes a rectifier power supply unit, a leakage current detection unit, and a control unit; the first mutual inductor module is connected to the leakage current detection unit; the second mutual inductor module is connected to the self-test module and ground respectively; The self-test module is connected to the rectifier power supply unit and the control unit respectively; The rectifier power supply unit is connected to the power line and the leakage current detection unit respectively; the rectifier power supply unit is used to rectify the power signal of the power line and send it to the leakage current detection unit and the self-test module respectively; The leakage current detection unit is used to process the leakage current signal of the first mutual inductance module and send it to the control unit. The control unit is used to determine whether the processed leakage current signal exceeds a preset tripping threshold. If so, it sends a tripping signal to the tripping module. It also sends a self-test start signal to the self-test module according to a preset cycle. The control unit receives the self-test current signal from the self-test module and determines whether it exceeds the preset tripping threshold. If so, it sends a tripping signal to the tripping module. The self-test module is used to respond to the self-test start signal, connect the rectifier power supply unit and the second mutual inductor module, and send the self-test current signal in the connection link to the control unit; The trip module is used to perform a tripping operation after receiving a tripping signal.

2. The leakage current protection self-test device based on rectification and multiplexing according to claim 1, characterized in that, Both the first mutual inductance module and the second mutual inductance module are coils, and they are wound on the same iron ring.

3. The leakage current protection self-test device based on rectification and multiplexing according to claim 1, characterized in that, The self-test module includes a self-test switch unit and a sampling resistor unit that are interconnected. The self-test switch unit is connected to the second mutual inductance module and the control unit, respectively; The sampling resistor unit is connected to the control unit and the rectifier power supply unit respectively; The self-test switch unit is used to close the switch to connect the second mutual inductance module, the sampling resistor unit and the rectifier power supply unit after receiving the self-test start signal from the control unit; The sampling resistor unit is used to send the sampled self-test current signal to the control unit.

4. The leakage current protection self-test device based on rectification and multiplexing according to claim 2, characterized in that, The self-test module also includes a self-test power supply unit; the self-test power supply unit is connected to the control unit. The self-test power supply unit is used to supply power to the control unit after the self-test switch unit closes its switch.

5. The leakage current protection self-test device based on rectification and multiplexing according to claim 3, characterized in that, The self-test module also includes a manual switch unit; the manual switch unit is connected in parallel with the self-test switch unit; the manual switch unit is used to receive user commands and close the switch to connect the second mutual inductance module, the sampling resistor unit and the rectifier power supply unit.

6. The leakage current protection self-test device based on rectification and multiplexing according to claim 1, characterized in that, The leakage current detection unit is specifically used to filter and amplify the leakage current signal.

7. The leakage current protection self-test device based on rectification and multiplexing according to claim 1, characterized in that, The tripping module includes a tripping unit and a self-test level unit; the control unit is connected to the tripping unit and the self-test level unit respectively; The control unit is used to send the trip signal to the trip unit; The tripping unit is used to perform a tripping operation after receiving the tripping signal; the self-test level unit is used to collect the voltage signal of the tripping unit, generate a tripping result based on the voltage signal, and send it to the control unit.

8. The leakage current protection self-test device based on rectification and multiplexing according to claim 7, characterized in that, The tripping unit includes a tripping coil, a half-wave rectifier unit, and a thyristor connected in sequence; the tripping coil is connected to a power supply line. The thyristor is connected to the control unit and is used to respond to a trip signal by pulling the anode voltage down to below a preset threshold. The half-wave rectifier unit is connected to the self-test level unit; The half-wave rectifier unit is used to acquire the voltage signal between the trip coil and the thyristor and send it to the self-test level unit.

9. The leakage current protection self-test device based on rectification and multiplexing according to claim 8, characterized in that, The trip module also includes a voltage divider resistor unit; the voltage divider resistor unit is connected to the self-test level unit and ground respectively.

10. The leakage current protection self-test device based on rectification and multiplexing according to claim 1, characterized in that, The number of turns of the first mutual inductance module is greater than or equal to that of the second mutual inductance module.

Images