A working method of an electric leakage detection controller

Abstract

The application discloses and provides a working method of a leakage detection controller which can avoid leakage tripping of line-to-line capacitance, has high intelligent degree and is convenient to use. The leakage of line-to-line capacitance is automatically increased, so that the load electrical equipment can be normally used. When the actual leakage level is not high, the historical working condition is continuously used; when the actual leakage level is high, the automatic modification configuration setting is used. When the leakage of the load end exceeds the sum of the rated leakage I1 and the no-load leakage current value I0, the circuit breaker is driven to cut off the power. The application is applied to the technical field of power grid safety detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power grid safety detection, and particularly relates to a working method of a leakage detection controller. BACKGROUND

[0002] In order to guarantee the safe power supply for people's life and production, the power grid must be safe and reliable, that is, both the normal energy supply for life and production and the safety of people's life and property must be guaranteed, and when an accidental electric shock accident occurs, the safety of human life must be ensured first, and the power supply is cut off in time, so that the current scheme is to install electric shock safety devices, power circuit breakers and other devices in the power supply circuit, which has played a certain effect for many years, and has achieved fruitful results in the current power grid operation.

[0003] The safety leakage value is set according to the human body related factors in the power supply safety devices such as electric shock protector, power circuit breaker, and the related standards are formulated accordingly. The leakage current under normal circumstances should not exceed 20-30ma. For example, the Chinese patent document with publication number CN113363935A discloses a leakage protector, which includes a leakage protection circuit for collecting the leakage current on the line between the mains and the load, and comparing the collected leakage current with the preset threshold value. The corresponding preset threshold values are 5MA, 10MA and 30MA. If the leakage current is greater than the preset threshold value, the line between the mains and the load is disconnected. However, this standard is in great contradiction with the current actual situation. The reason is that the distribution capacitance between the power supply lines is inherent in the electrical characteristics and objectively exists. The longer the conductor, the greater the capacitance. The capacitance forms a certain capacitive path for alternating current, that is, the leakage between the conductors through the inter-line capacitance is inevitable, especially for today's huge power supply network. For some larger power supply networks, it is common to have tens of kilometers of conductors, and the leakage current between the conductors through the inter-line capacitance has exceeded the current value set in the electric shock protector, power circuit breaker and other devices, causing the traditional electric shock protector, power circuit breaker to be unable to use. The purchased equipment product installed in the power supply circuit trips and cannot operate normally according to the design. Therefore, the Chinese patent document with publication number CN204012649U discloses a leakage protector with adjustable sensitivity, which specifically includes a zero sequence current transformer for sensing the zero sequence current, a controller for receiving the induced current signal and generating a control signal, and a circuit breaker for responding to the control signal and generating a tripping action. The signal input end of the controller is also connected with a sensitivity adjuster, which is used to change the size of the current signal input to the controller, thereby changing the sensitivity of the entire leakage protector in responding to the zero sequence current and generating a tripping action. However, this type of leakage protector needs manual adjustment, and professional personnel need to detect the circuit during installation and then adjust the sensitivity. If the sensitivity is adjusted too low, the tripping action will be quite slow, which will potentially cause great safety hazards. If the sensitivity is adjusted too high, the tripping action will be quite sensitive, and the use of this type of leakage protector will be lost.

[0004] In summary, the existing electric shock protector, power circuit breaker and other original power supply safety devices cannot be applied to all current situations. It is urgent for power grid practitioners to redevelop and design the power supply safety devices for power supply lines with long lines, large inter-line capacitance and many electrical equipment. SUMMARY

[0005] The present application solves the problem of overcoming the deficiencies of the prior art, providing a leakage detection controller working method which can avoid the occurrence of tripping due to line capacitance and also play a protective role, and is highly intelligent and easy to use.

[0006] The technical scheme adopted by the present application is: a leakage detection controller working method, the leakage detection controller used in the method comprising a leakage detection unit, a controller, a circuit breaker, and a power module; the leakage detection unit, the circuit breaker, and the power module are all electrically connected to the controller; the leakage detection unit is used to collect leakage current on a line between commercial power and a load M; the power module is used to provide working power for the controller; and the leakage detection controller working method comprises the following steps:

[0007] a. The load M is not connected to the line, and the leakage detection unit detects an empty load leakage current value I0;

[0008] b. After the controller obtains the empty load leakage current value I0 detected by the leakage detection unit, the controller sets the sum of a rated leakage amount I1 and the empty load leakage current value I0 as a maximum leakage amount I max ;

[0009] c. The load M is connected to the line, and the leakage detection unit detects leakage current in the line and feeds back to the controller;

[0010] d. When the leakage detection unit detects that the leakage current is not greater than the maximum leakage amount I max , the circuit breaker does not act; when the controller finds that the leakage detection unit detects that the leakage current is greater than the maximum leakage amount I max , the controller controls the circuit breaker to cut off the connection between the commercial power and the load M.

[0011] Further, the leakage detection controller further comprises an indicator light module electrically connected to the controller, and the indicator light module comprises a red light L1, a green light L2, and a yellow light L3; in step a, when the leakage detection unit detects the empty load leakage current value I0, the yellow light L3 is on; after entering step b, the controller sets the sum of the rated leakage amount I1 and the empty load leakage current value I0 as the maximum leakage amount I max , the yellow light L3 is turned off, and the green light L2 is turned on; after the green light L2 is turned on, it indicates that the leakage detection controller can work normally, and at the same time, it indicates that the load M can be connected to the line; in step d, when the controller finds that the leakage detection unit detects that the leakage current is greater than the maximum leakage amount I max , the circuit breaker acts, and at the same time, the red light L1 is turned on, and the green light L2 and the yellow light L3 are turned off.

[0012] Further, the circuit breaker is an electromagnetic circuit breaker, when the input current of the electromagnetic circuit breaker is greater than the rated current of the electromagnetic circuit breaker, the electromagnetic circuit breaker cuts off the connection between the commercial power and the load M.

[0013] Further, the controller comprises a first controller and a second controller, a switching unit is arranged between the controller and the leakage detection unit, and the power module provides working power for the switching unit; when the power module has sufficient power, the switching unit connects the output end of the leakage detection unit to the second controller; when the power module has insufficient power, the switching unit connects the output end of the leakage detection unit to the first controller.

[0014] Further, the first controller is a current transformer, when the power module has insufficient power, the switching unit connects the output end of the leakage detection unit to the input end of the current transformer, and the output end of the current transformer is connected to the input end of the circuit breaker.

[0015] Further, the second controller comprises a CPU control unit, and the power module is configured to provide working power for the CPU control unit; when the power module has sufficient power, the switching unit connects the output end of the leakage detection unit to the input end of the CPU control unit, and the control end of the CPU control unit is connected to the triggering end of the circuit breaker.

[0016] Further, in step d, when the controller finds that the leakage detection unit 1 detects that the leakage current is greater than the maximum leakage current I max , the controller controls the circuit breaker to cut off the connection between the commercial power and the load M, at this time, the load M is not connected to the line, and the leakage detection unit detects the no-load leakage current value I1 again after leakage, the controller compares the no-load leakage current value I1 after leakage with the no-load leakage current value I0, and if the no-load leakage current value I1 after leakage is greater than the no-load leakage current value I0, it is determined that the line is faulty and an alarm is issued.

[0017] Further, in step b, after the controller obtains the no-load leakage current value I0 detected by the leakage detection unit, the controller compares the no-load leakage current value I0 with the set no-load early warning leakage value, and if the no-load leakage current value I0 is greater than the set no-load early warning leakage value, the controller issues a warning information, and the staff should check the line according to the warning information.

[0018] The beneficial effects of the present application are: since the leakage of the line-to-line capacitance is automatically increased in the present application, it ensures that the load electrical equipment can be normally used, when the actual leakage level is not high, it continues to run according to the historical working condition, when the actual leakage level is high, it automatically modifies the configuration setting and runs, when the load end leakage exceeds the sum of the rated leakage I1 and the no-load leakage current value I0, the circuit breaker is driven to disconnect the power, which solves the adaptation of the electric shock protection device and the electrical network, and the personal and property safety, which facilitates the selection and debugging application of power design and installation, and in actual use, the leakage detection controller can automatically increase the leakage current of the line-to-line capacitance according to the actual situation of the line, which is very convenient to use. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the schematic diagram of the present application. DETAILED DESCRIPTION

[0020] As Figure 1 shown, a working method of a leakage detection controller, the leakage detection controller used in the method comprises a leakage detection unit 1, a controller 2, a circuit breaker 3, and a power module 4; the leakage detection unit 1, the circuit breaker 3, and the power module 4 are all electrically connected with the controller 2, the leakage detection unit 1 is used for collecting the leakage current on the line between the commercial power and the load M, the power module 4 is used for providing working power for the controller 2, and the working method of the leakage detection controller comprises the following steps:

[0021] a. The load M is not connected to the line first, and the leakage detection unit 1 detects the no-load leakage current value I0;

[0022] b. After the controller 2 obtains the no-load leakage current value I0 detected by the leakage detection unit 1, the sum of the rated leakage I1 and the no-load leakage current value I0 is set as the maximum leakage I max ; in this step b, after the controller 2 obtains the no-load leakage current value I0 detected by the leakage detection unit 1, the controller 2 compares the no-load leakage current value I0 with the set no-load early warning leakage value, the no-load early warning leakage value is set to 20mA-30mA, and specifically can be set to 30mA, if the no-load leakage current value I0 is greater than the set no-load early warning leakage value, the controller 2 sends a warning information, and the working personnel should check the line according to the warning information, such as checking whether the conductor in the line is damaged or aged, and eliminating the fault. After the fault is eliminated, if the no-load leakage current value I0 is still greater than the set no-load early warning leakage value, it can be considered that the no-load leakage current value I 0为 is the leakage current of the line-to-line capacitance;

[0023] c. When load M is connected to the line, the leakage current detection unit 1 detects the leakage current in the line and feeds it back to the controller 2;

[0024] d. The leakage current detected by the leakage detection unit 1 is not greater than the maximum leakage current I. max When the circuit breaker 3 does not operate, the controller 2 detects that the leakage current detected by the leakage current detection unit 1 is greater than the maximum leakage current I. max At this time, the controller 2 controls the circuit breaker 3 to disconnect the connection between the mains power and the load M. In this step d, when the controller 2 detects that the leakage current detected by the leakage current detection unit 1 is greater than the maximum leakage current I... max When the controller 2 controls the circuit breaker 3 to disconnect the connection between the mains power and the load M, the load M is not connected to the line. The leakage current detection unit 1 detects the no-load leakage current value I1 again. The controller 2 obtains the no-load leakage current value I1 and compares it with the no-load leakage current value I0. If the no-load leakage current value I1 is greater than the no-load leakage current value I0, the line fault is determined and an alarm is issued.

[0025] In this embodiment, the leakage current detection controller further includes an indicator light module 5 electrically connected to the controller 2. The indicator light module 5 includes a red light L1, a green light L2, and a yellow light L3. In step a, when the leakage current detection unit 1 detects the no-load leakage current value I0, the yellow light L3 illuminates. When proceeding to step b, the controller 2 sets the sum of the rated leakage current I1 and the no-load leakage current value I0 as the maximum leakage current I. max Then, the yellow light L3 goes out, and the green light L2 lights up; when the green light L2 lights up, it indicates that the leakage current detection controller can work normally, and at the same time, it indicates that the load M can be connected to the line; in step d, when the controller 2 finds that the leakage current detection unit 1 detects a leakage current greater than the maximum leakage current I, max When the circuit breaker 3 operates, the red light L1 illuminates, while the green light L2 and the yellow light L3 turn off. In this embodiment, the design of the indicator light module 5 enables users to quickly identify the operating status of the leakage current detection controller, ensuring electrical safety.

[0026] In this embodiment, the circuit breaker 3 is an electromagnetic circuit breaker. When the current input to the input terminal of the electromagnetic circuit breaker is greater than the rated current of the electromagnetic circuit breaker, the electromagnetic circuit breaker disconnects the connection between the mains power and the load M.

[0027] In this embodiment, the controller 2 includes a first controller 21 and a second controller 22. A switching unit 6 is provided between the controller 2 and the leakage current detection unit 1. The power module 4 provides operating power to the switching unit 6. When the power module 4 has sufficient power, the switching unit 6 connects the output terminal of the leakage current detection unit 1 to the second controller 22. When the power module 4 has insufficient power, the switching unit 6 connects the output terminal of the leakage current detection unit 1 to the first controller 21.

[0028] In this embodiment, the first controller 21 is a current transformer. When the power supply module 4 is low on power, the switching unit 6 connects the output terminal of the leakage current detection unit 1 to the input terminal of the current transformer, and the output terminal of the current transformer is connected to the input terminal of the circuit breaker 3.

[0029] In this embodiment, the second controller 22 includes a CPU control unit, and the power module 4 is used to provide working power to the CPU control unit. When the power module 4 has sufficient power, the switching unit 6 connects the output terminal of the leakage current detection unit 1 to the input terminal of the CPU control unit, and the control terminal of the CPU control unit is connected to the trigger terminal of the circuit breaker 3.

[0030] In this embodiment, when the three-phase four-wire power grid is put into operation, it must pass through the leakage current detection unit and then be connected to the input terminal of the circuit breaker. The output terminal of the circuit breaker is connected to the load electrical equipment.

[0031] The actual operating conditions at the site have been collected by the detection coil of the leakage current detection unit and input into the CPU circuit of the controller for recording, comparison, calculation, storage, and adaptation settings. When the actual leakage current level is not high, the system continues to operate according to the historical operating conditions. When the actual leakage current level is high, the system automatically modifies the configuration settings and operates accordingly.

[0032] This invention can detect and calculate the current of the load electrical equipment and modify or reset the output according to the preset. When the leakage current at the load end exceeds the set value during operation, it will drive the circuit breaker to cut off the power and trigger an audible and visual alarm.

[0033] In this embodiment, due to the existence of the power supply system wire between the capacitor leakage phenomenon, with the increase of the length of the wire, the capacitor leakage value will also increase, when the length of the wire to a certain length, the capacitor leakage will produce a large leakage current, will cause the leakage switch trip, unable to work normally. Therefore, the reason factory area most cannot install leakage switch, plus the number of factory equipment is numerous, the length of the wire will increase, the capacitor leakage will also increase, the normal situation between the ground wire and the zero line leakage reaches more than 20-30ma, resulting in the leakage switch cannot be used, if blindly increase the leakage setting value of the leakage switch of the equipment, the personal safety cannot provide protection guarantee, and the application adopts the working method of the new leakage detection controller, the actual working condition of the operation site is collected and input to the CPU circuit of the controller, record, compare, operation, storage, and adaptive setting operation, when the actual leakage level is not high, continue to run according to the historical working condition, when the actual leakage level is high, carry out automatic modification configuration setting operation. When the load end leakage exceeds the set value in the operation, the circuit breaker will be driven to cut off the power and sound and light alarm, solve the adaptation of electric shock protection equipment and power network and personal and property safety, facilitate the selection and debugging application of power design and installation.

Claims

1. A method for operating a leakage current detection controller, wherein the leakage current detection controller used in the method includes a leakage current detection unit (1), a controller (2), a circuit breaker (3), and a power supply module (4); the leakage current detection unit (1), the circuit breaker (3), and the power supply module (4) are all electrically connected to the controller (2); the leakage current detection unit (1) is used to detect leakage current on the line between the mains power and the load (M); and the power supply module (4) is used to provide operating power to the controller (2), characterized in that: The operation method of the leakage current detection controller includes the following steps: a. The load (M) is not connected to the line at first, and the leakage detection unit (1) detects the no-load leakage current value (I0). b. After the controller (2) obtains the no-load leakage current value (I0) detected by the leakage detection unit (1), it sets the sum of the rated leakage current (I1) and the no-load leakage current value (I0) as the maximum leakage current (I1). max ); c. When the load (M) is connected to the line, the leakage current detection unit (1) detects the leakage current in the line and feeds it back to the controller (2). d. The leakage current detection unit (1) detects a leakage current that is not greater than the maximum leakage current (I). max When the circuit breaker (3) does not operate; when the controller (2) detects that the leakage current detected by the leakage detection unit (1) is greater than the maximum leakage current (I), the circuit breaker (3) does not operate; max When the controller (2) controls the circuit breaker (3) to disconnect the connection between the mains power and the load (M); In step b, if the controller (2) obtains the no-load leakage current value (I0) detected by the leakage detection unit (1), the controller (2) compares the no-load leakage current value (I0) with the set no-load warning leakage value. If the no-load leakage current value (I0) is greater than the set no-load warning leakage value, the controller (2) issues a warning message, and the staff should check the line according to the warning message.

2. The working method of the leakage current detection controller according to claim 1, characterized in that: The leakage current detection controller also includes an indicator light module (5) electrically connected to the controller (2). The indicator light module (5) includes a red light (L1), a green light (L2), and a yellow light (L3). In step a, when the leakage current detection unit (1) detects the no-load leakage current value (I0), the yellow light (L3) lights up. When step b is reached, the controller (2) sets the sum of the rated leakage current (I1) and the no-load leakage current value (I0) as the maximum leakage current (I). max After that, the yellow light (L3) goes out and the green light (L2) turns on; when the green light (L2) turns on, it indicates that the leakage current detection controller can work normally, and at the same time it indicates that the load (M) can be connected to the line; in step d, when the controller (2) finds that the leakage current detection unit (1) detects that the leakage current is greater than the maximum leakage current (I max When the circuit breaker (3) operates, the red light (L1) lights up, and the green light (L2) and the yellow light (L3) turn off.

3. The working method of the leakage current detection controller according to claim 2, characterized in that: The circuit breaker (3) is an electromagnetic circuit breaker. When the current input to the input terminal of the electromagnetic circuit breaker is greater than the rated current of the electromagnetic circuit breaker, the electromagnetic circuit breaker disconnects the connection between the mains power and the load (M).

4. The working method of a leakage current detection controller according to claim 3, characterized in that: The controller (2) includes a first controller (21) and a second controller (22). A switching unit (6) is provided between the controller (2) and the leakage detection unit (1). The power module (4) provides working power to the switching unit (6). When the power module (4) has sufficient power, the switching unit (6) connects the output terminal of the leakage detection unit (1) to the second controller (22). When the power module (4) has insufficient power, the switching unit (6) connects the output terminal of the leakage detection unit (1) to the first controller (21).

5. The working method of a leakage current detection controller according to claim 4, characterized in that: The first controller (21) is a current transformer. When the power supply module (4) is low on power, the switching unit (6) connects the output of the leakage detection unit (1) to the input of the current transformer. The output of the current transformer is connected to the input of the circuit breaker (3).

6. The working method of a leakage current detection controller according to claim 4, characterized in that: The second controller (22) includes a CPU control unit. The power module (4) is used to provide working power to the CPU control unit. When the power module (4) has sufficient power, the switching unit (6) connects the output terminal of the leakage detection unit (1) to the input terminal of the CPU control unit. The control terminal of the CPU control unit is connected to the trigger terminal of the circuit breaker (3).

7. The method of operating a leakage current detection controller according to any one of claims 1 to 6, characterized in that: In step d, when the controller (2) detects that the leakage current detected by the leakage detection unit (1) is greater than the maximum leakage current (I), max When the controller (2) controls the circuit breaker (3) to disconnect the connection between the mains power and the load (M), the load (M) is not connected to the line. The leakage detection unit (1) detects the no-load leakage current value (I2) after leakage again. The controller (2) obtains the no-load leakage current value (I2) after leakage and compares it with the no-load leakage current value (I0). If the no-load leakage current value (I2) after leakage is greater than the no-load leakage current value (I0), the line fault is determined and an alarm is issued.

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