DE102023109671A1 - Residual current protection device, power distribution system and trip control method - Google Patents

Abstract

The present application provides a residual current protection device, a power distribution system and a trip control method. The residual current protection device comprises: a tripping module, a residual current detection module and a processing module, the tripping module being connected between a power source and a load, the residual current detection module being connected in a power supply line between the tripping module and the load, the residual current detection module being designed to generate a residual current signal, which is used to indicate a fault current in the power supply line of the load, and send the fault current signal to the processing module, the processing module being adapted to depend on the fault current signal and a trip curve in the case where the fault current is larger at any frequency as a corresponding trip current threshold, to control the trip module to trip to disconnect the power supply line of the load, the trip curve being used to indicate a relationship between the frequency of the fault current and the trip current threshold, and the trip curve based on an inherent Fault current of the power supply line is determined. The present solution can improve the stability of power distribution.

Description

TECHNICAL FIELD

The present application relates to the technical field of electrical engineering, in particular to a residual current protection device, a power distribution system and a method for tripping control.

STATE OF THE ART

A Residual Current Operated Protective Device (RCD) is a protective device that, when the residual current of a circuit reaches a certain value under given conditions, causes a contact to be actuated, thus disconnecting the main circuit. The residual current device can trip in the event of an electrical leakage to prevent electric shock, electrical fire and damage to electrical equipment. It is widely used in household and industrial power distribution systems.

Currently, the residual current device performs tripping according to a standard tripping curve when the residual current reaches an operating current defined by the tripping curve.

However, in a power distribution system that includes high switching frequency loads such as a frequency converter and a variable frequency drive, a high frequency fault current exists. This high-frequency residual current does not result from a failure, but it does result in the residual current protective device tripping. This would therefore lead to incorrect action of the residual current protection device and affect the stability of the power distribution.

CONTENT OF THE INVENTION

In view of this, the residual current protection device, the power distribution system and the trip control method provided by the present application can improve the stability of power distribution.

According to a first aspect of the embodiments of the present application, there is provided a residual current protection device comprising a tripping module, a residual current detection module and a processing module; wherein the trip module is connected between a power source and a load, the fault current detection module is connected in a power supply line between the trip module and the load, the fault current detection module is designed to generate a fault current signal used to indicate a fault current in the power supply line of the load, to detect and send the fault current signal to the processing module; wherein the processing module is adapted, depending on the fault current signal and a trip curve in the case where the fault current at any frequency is greater than a corresponding trip current threshold, to control the trip module to trip to disconnect the power supply line of the load, wherein the trip curve is used to indicate a relationship between the frequency of the fault current and the trip current threshold, and wherein the trip curve is determined based on an inherent fault current of the power supply line.

According to a second aspect of the exemplary embodiments of the present application, a method for tripping control for a residual current protection device is provided, wherein the residual current protection device comprises a tripping module and a residual current detection module, the tripping module being connected between a power source and a load, the residual current detection module being in a power supply line between the tripping module and the load is connected, the method comprising: obtaining a fault current signal detected by the fault current detection module that is used to indicate a fault current in the power supply line of the load; and controlling the tripping module depending on the fault current signal and a tripping curve and in the case where the fault current at any frequency is greater than a corresponding tripping current threshold, so that the tripping module trips to disconnect the power supply line of the load, the tripping curve for indicating a Association between the frequency of the fault current and the tripping current threshold is used, and wherein the tripping curve is determined based on an inherent fault current of the power supply line.

According to a third aspect of the embodiments of the present application, there is provided a power distribution system comprising: a power source, at least one load, and at least one residual current protection device in the first aspect; wherein an input of the residual current protection device or each of the residual current protection devices is connected to the power source; and wherein an output of the residual current protection device or each of the residual current protection devices is connected to the at least one load.

According to a fourth aspect of the embodiments of the present application, there is provided an electronic device which comprises: a processor, a communication interface, a memory and a communication bus, the processor, the memory and the communication interface communicating with each other via the communication bus; and wherein the memory is used to store at least one executable instruction that causes the processor to perform the steps corresponding to the trigger control method provided in the second aspect.

According to a fifth aspect of the embodiments of the present application, there is provided a computer-readable storage medium on which computer instructions are stored, the computer instructions, when executed by a processor, causing that processor to perform the trigger control method provided in the second aspect.

According to a sixth aspect of the embodiments of the present application, there is provided a computer program product that is physically stored on a computer-readable medium and includes computer-executable instructions, the computer-executable instructions, when executed, causing at least one processor to perform the trigger control method provided in the second aspect.

With the solutions described above, the residual current detection module detects a residual current signal, and the processing module, depending on the residual current signal and the tripping curve, controls the tripping module so that it trips. Here, in the case where the fault current at any frequency is greater than a tripping current threshold corresponding to that frequency on the tripping curve, the processing module controls the tripping module to trip to disconnect the power supply line of the load. Since the trip curve is determined based on the inherent fault current of the load power supply line, a trip current threshold corresponding to the frequency of the inherent fault current on the trip curve is larger than the amplitude of the inherent fault current, which ensures that the inherent fault current of the load power supply line does not leads to the tripping of the tripping module, which reduces the incorrect actions of the residual current protection device and thus improves the stability of the power distribution.

BRIEF DESCRIPTION OF THE FIGURES

• 1 shows a schematic view of a residual current protection device according to an exemplary embodiment of the present application;
• 2 shows a schematic view of a residual current protection device according to a further exemplary embodiment of the present application;
• 3 shows a schematic view of a trigger curve according to an exemplary embodiment of the present application;
• 4 shows a schematic view of a residual current protection device according to yet another exemplary embodiment of the present application;
• 5 shows a schematic view of a residual current protection device that includes a communication module, according to an exemplary embodiment of the present application;
• 6 shows a schematic view of an electronic device according to another embodiment of the present application;
• 7 shows a flowchart of a method for trigger control according to an exemplary embodiment of the present application;
• 8th shows a schematic view of a power distribution system according to an embodiment of the present application; and
• 9 shows a schematic view of an electronic device according to an exemplary embodiment of the present application.

DETAILED EMBODIMENTS

As described above, the existing residual current device has a standard trip curve, and after this residual current device is installed in the power distribution system and the residual current in the power supply line reaches an operating current defined by the trip curve, the residual current device trips to disconnect the power supply line of the load. However, the types of loads in different power distribution systems are different. In a power distribution system that includes high switching frequency loads, such as a frequency converter and a variable frequency drive, a high frequency fault current is generated in the load's power supply line. Based on the standard trip curve, this high-frequency residual current causes the residual current device to trip, but this high-frequency residual current is not caused by a failure. This would therefore be a wrong action by the Feh current protection device and thus impair the stability of the power distribution.

In embodiments of the present application, the tripping curve of the residual current protection device is determined based on the inherent fault current of the power supply line, the tripping curve defining a relationship between the frequency of the fault current and the tripping current threshold, in the case where the fault current is greater at any frequency in the power supply line than the trip current threshold defined by the trip curve, the residual current device trips to disconnect the power supply line of the load. Since the trip curve is determined based on the inherent fault current of the power supply line, the frequency of the inherent fault current of the power supply line can be designed to correspond to a larger trip current threshold. This ensures that the inherent fault current of the power supply line does not cause the tripping of the residual current protective device, thereby reducing the incorrect actions of the residual current protective device and improving the stability of power distribution.

Hereinafter, the residual current protection device, the power distribution system and the trip control method provided by the embodiments of the present application will be described in more detail with reference to the accompanying drawings.

Residual current protection device

1 shows a schematic view of a residual current protection device provided by an embodiment of the present application. As in 1 shown, the residual current protection device 10 comprises a tripping module 11, a residual current detection module 12 and a processing module 13. The tripping module 11 is connected between a power source 20 and a load 30, the residual current detection module 12 being connected in a power supply line between the tripping module 11 and the load 30. The fault current detection module 12 may detect a fault current signal used to indicate a fault current in the power supply line of the load 30 and send the fault current signal to the processing module 13. The processing module 13 may control the trip module 11 to trip to disconnect the power supply line of the load 30 depending on the fault current signal and a trip curve in the case where the fault current at any frequency is greater than a corresponding trip current threshold. The trip curve is used to indicate a relationship between the frequency of the fault current and the trip current threshold, the trip curve being determined based on an inherent fault current of the power supply line of the load 30.

The tripping curve can indicate the association between the frequency of the fault current and the tripping current threshold, wherein tripping current thresholds corresponding to fault currents at different frequencies can be determined according to the tripping curve. A trip current threshold is a critical current value for the operation of the trip module 11. If the fault current at a specific frequency is greater than the corresponding trip current threshold, it indicates that failures such as short circuit and electrical leakage occur on the load side, causing the processing module 13 to trigger the trip module 11 controls to trip to disconnect the power supply line of the load 30 and stop the power supply to the load 30.

In the exemplary embodiments of the present application, the fault current detection module 12 detects the fault current signal, the processing module 13 depending on the fault current signal and the tripping curve controls the tripping module 11 so that it trips, the processing module 13 in the case where the fault current is greater at any frequency as a tripping current threshold corresponding to this frequency is on the tripping curve, controls the tripping module 11 to trip to disconnect the power supply line of the load 30. Since the trip curve is determined based on the inherent fault current of the power supply line of the load 30, a trip current threshold corresponding to the frequency of the inherent fault current on the trip curve is larger than the amplitude of the inherent fault current, which ensures that the inherent fault current of the power supply line of the load 30 does not trigger the tripping module 11, which reduces the incorrect actions of the residual current protection device 10 and thus improves the stability of the power distribution.

2 shows a schematic view of a residual current protection device according to a further exemplary embodiment of the present application. As in 2 shown, the processing module 13 includes a digital filter unit 131 and a trip control unit 132. The digital filter unit 131 can determine the inherent fault current of the power supply line of the load 30 depending on a target current of the load 30, an operating frequency of the load 30 and a cable length of the power supply line of the load 30 and depending on the inherent fault current of the power supply line of the load 30, the trip curve is generated ren, so that a trip current threshold on the trip curve corresponding to the inherent fault current of the power supply line of the load 30 is greater than the amplitude of the inherent fault current. The trip control unit 132 can control the trip module 11 to trip depending on the fault current signal and the trip curve in the case where the fault current at any frequency in the power supply line of the load 30 is greater than a trip current threshold corresponding to this frequency on the trip curve. to disconnect the power supply line of the load 30.

In the embodiments of the present application, the target current as well as the operating frequency of the load 30 and the cable length of the power supply line influence the inherent fault current of the power supply line of the load 30. For example, an increase in the cable length leads to an increase in the inherent fault current of the power supply line of the load 30, where the operating frequency of the load 30 influences the frequency of the inherent fault current, and wherein the target current of the load 30 influences the amplitude of the inherent fault current. The digital filter unit 131 determines the inherent fault current of the power supply line of the load 30 depending on the target current, as well as the operating frequency of the load 30 and the cable length of the power supply line to ensure the accuracy of the determined inherent fault current.

The digital filter unit 131 can perform digital filter processing on the fault current signal and send the result of the digital filter processing to the trip control unit 132. The trip control unit 132 may then determine whether a fault current at any frequency is greater than a trip current threshold corresponding to that frequency on the trip curve, and upon determining that the fault current at any frequency is greater than the trip current threshold corresponding to that frequency on the trip curve, control the trigger module 11 so that it triggers.

In one possible implementation, a target frequency is predetermined, wherein the trip control unit 132 can determine, depending on the fault current signal, whether a fault current corresponding to the target frequency is greater than a first current threshold, the first current threshold being less than a trip current threshold corresponding to the target frequency on the trip curve. If the fault current corresponding to the target frequency is greater than the first current threshold, the trip control unit 132 controls the trip module 11 to trip to disconnect the power supply line of the load 30.

For example, the target frequency is 10 kHz, the first current threshold is 5 A, and the trip current threshold corresponding to the fault current at the frequency of 10 kHz on the trip curve is 10 A. If the trip control unit 132 determines that the fault current at the frequency of 10 kHz in the power supply line of the load 30 is greater than 5 A, it will control the trip module 11 to trip to disconnect the power supply line of the load 30.

In the embodiment of the present application, a user can set the target frequency and the first current threshold as needed, the first current threshold being smaller than the tripping current threshold corresponding to the target frequency on the tripping curve, in the case where the fault current at the target frequency is greater than the first Current threshold value is, the trip control unit 132 controls the trip module 11 so that it trips. If the user believes that the triggering current threshold corresponding to the target frequency on the triggering curve is too large and there is a safety risk, the user can set a first current threshold corresponding to the target frequency so that the first current threshold is smaller than the triggering current threshold corresponding to the target frequency on the triggering curve, wherein in the case where the fault current at the target frequency is greater than the first current threshold, the trip control unit 132 can control the trip module 11 to trip. This allows the individual requirements of different users to be met and users' experiences when using the residual current device 10 to be improved.

It should be noted that there may be one or more target frequencies, whereby in the case of multiple target frequencies a corresponding first current threshold value is provided for each of the target frequencies, whereby first current threshold values corresponding to different target frequencies may be the same or different.

In one possible implementation, it is provided that the digital filter unit 131 generates the tripping curve depending on the inherent fault current of the power supply line of the load 30 and a preset upper limit tripping curve and lower limit tripping curve, with a tripping current threshold corresponding to any fault current frequency on the tripping curve between Trip current thresholds that correspond to this fault current frequency on the upper limit trip curve or the lower limit trip curve.

3 shows a schematic view of a trigger curve according to an exemplary embodiment of the present application. As in 3 shown, the frequency of the residual current in Hertz (Hz) is shown on the abscissa and the ratio of the tripping current threshold value to the target leakage operating current (Idn) of the residual current protective device 10 is shown on the ordinate. Curve 301 represents an upper limit trip curve and curve 302 represents a lower limit trip curve. The trigger curve generated by the digital filter unit 131 lies between the curve 301 and the curve 301.

In the embodiment of the present invention, the upper limit trip curve and the lower limit trip curve are preset, and the digital filter unit 131 in the case where, depending on the inherent fault current of the power supply line of the load 30, a trip curve intermediate between the upper limit trip curve and the lower limit Tripping curve is generated, avoids that the tripping module 11 does not trip due to a tripping current threshold value that is too high when a failure occurs and that the tripping module 11 often carries out incorrect actions due to a tripping current threshold value set that is too small. Thereby, under the premise of ensuring the safety of the power distribution system, the wrong actions of the residual current protection device 10 can be reduced.

As in 3 As shown, curve 303 is a standard tripping curve defined by relevant standards, with the upper limit tripping curve (curve 301) located below curve 303 to ensure that, under the influence of various faults, the tripping current threshold determined from the tripping curve meets a given value of the relevant Standards does not exceed, which ensures that the residual current protective device 10 meets the requirements of the relevant standards.

In a possible implementation, it is provided that the digital filter unit 131 can be used to update the tripping curve after the tripping control unit 132 has controlled the tripping module 11 to trip due to a fault current at a specific frequency greater than the tripping current threshold value corresponding to this frequency on the tripping curve and increasing the trip current threshold corresponding to that frequency on the updated trip curve, the trip current threshold corresponding to that frequency on the updated trip curve being less than a trip current threshold corresponding to that frequency on the high limit trip curve.

For example, the trip current threshold corresponding to the fault current at 10 kHz on the trip curve is 10 A, where the trip current threshold corresponding to the fault current at 10 kHz on the high limit trip curve is 15 A. When the fault current at 10 kHz in the power supply line of the load 30 is 12 A, the trip control unit 132 controls the trip module 11 to trip due to the fault current of 12 A greater than the trip current threshold of 10 A. The digital filter unit 131 then updates the trip curve and increases the trip current threshold corresponding to the frequency of 10 kHz on the trip curve so that a trip current threshold corresponding to the frequency of 10 kHz on the updated trip curve is greater than 10 A and less than or equal to 15 A.

After the tripping control unit 132 controls the tripping module 11 to trip due to a fault current at a specific frequency greater than the tripping current threshold corresponding to that frequency on the tripping curve, the digital filter unit 131 may update the tripping curve by the digital filtering unit 131 to the tripping current threshold corresponding to that frequency on the tripping curve Increase trip current threshold according to preset current increase. For example, the preset current increase is 1 A, with the trip current threshold corresponding to the fault current at 10 kHz on the trip curve being 10 A, with the trip current threshold corresponding to the fault current at 10 kHz on the high limit trip curve being 15 A, with the fault current at 10 kHz in the power supply line of the load 30 is 12 A, so that after the trip control unit 132 controls the trip module 11 to trip, the digital filter unit 131 sets the trip current threshold corresponding to the fault current at 10 kHz on the trip curve from 10 A to 11 A.

In the exemplary embodiments of the present application it is provided that after the tripping module 11 has tripped due to a fault current at a specific frequency greater than the corresponding tripping current threshold, the digital filter unit 131 updates the tripping curve in order to increase the tripping current threshold corresponding to this frequency on the tripping curve, thereby realizing adaptive adjustment of the trip curve, so that the residual current protection device 10 can be better adapted to the load 30 and the power distribution system, thereby protecting the power distribution system more effectively and ensuring the reliability of the power distribution system.

4 shows a schematic view of a residual current protection device according to an exemplary embodiment of the present application. As in 4 shown, the processing module 13 includes an upper limit detection unit 133. The upper limit detection unit 133 can, depending on the fault current signal, determine a current amplitude obtained by superimposing fault currents at different frequencies and send the determined current amplitude to the tripping control unit 132. The trip control unit 132 may determine whether the current amplitude is greater than a second current threshold, and controls the trip module 11 in the case where the current amplitude is greater than the second current threshold so that it trips to disconnect the power supply line of the load 30.

In the exemplary embodiments of the present application it is provided that if the ratio of a low-frequency fault current to a high-frequency fault current in the power supply line of the load 30 is comparatively small, the low-frequency fault current is covered by the high-frequency fault current. It is not possible to determine whether the amplitude of the low-frequency fault current is greater than the corresponding tripping current threshold value. Thus, the trip module 11 does not trip when a failure occurs in the low-frequency fault current, which causes a safety risk. When the upper limit detection unit 133 determines that a current amplitude obtained by superimposing fault currents at different frequencies is larger than the second current threshold, the ratio of the low-frequency fault current to the high-frequency fault current is comparatively small, with the low-frequency fault current being replaced by the high-frequency fault current is covered. Now, the tripping control unit 132 controls the tripping module 11 to trip in order to avoid the following situation: that it is not possible to determine whether the amplitude of the low-frequency fault current is greater than the corresponding tripping current threshold, resulting in the tripping module 11 not tripping. In this way, the safety of power distribution is guaranteed.

5 shows a schematic view of a residual current protection device according to an exemplary embodiment of the present application. As in 5 shown, the residual current protection device 10 includes a communication module 14, wherein the processing module 13 includes a unit for analyzing frequency ranges 134. The frequency range analysis unit 134 may analyze the fault current signal with respect to the frequency range, determine frequency information of a fault current greater than the corresponding trip current threshold, and send the determined frequency information to the communication module 14.

The communication module 14 can send the received frequency information to a data collector that is located outside the residual current protection device 10.

The frequency range analysis unit 134 can determine the frequency of a fault current that causes the tripping module 11 to trip by analyzing the fault current information with respect to the frequency range. The frequencies of fault currents generated by different types of failures are different. After the communication module 14 sends the frequency information of the fault current that causes tripping to the data collector, the data collector can determine the type of failure that causes the fault current device 10 to trip depending on the frequency information, thereby facilitating recovery of the failure of the power distribution system and the user experience is improved.

For example, in a power distribution system in which loads include a frequency converter, the frequency of the residual current causing the residual current device 10 to trip is 50 Hz, it may be a failure in the grounding of the input of the frequency converter. If the frequency of the residual current causing the residual current protection device 10 to trip is 5 kHz and the switching frequency of the converter is 5 kHz, it may be a failure in the grounding of an IGBT (Insulated Gate Bipolar Transistor).

Optionally, the frequency range analysis unit 134 may analyze the fault current signal by a Fast Fourier Transform (FFT) to determine the frequency of the fault current for tripping.

6 shows a schematic view of a residual current protection device according to an exemplary embodiment of the present application. As in 6 shown, the fault current detection module 12 includes a zero-sequence current transformer (ZCT) 121, an excitation circuit 122 and an operational amplifier 123. The zero-current transformer 121 is connected in the power supply line between the tripping module 11 and the load 30. The zero current converter 121 is connected to the excitation circuit 122 and the operational amplifier 123. The excitation circuit 122 can provide the zero-current converter 121 with an excitation signal. The zero current converter 121 can detect the fault current in the power supply line of the load 30 based on the excitation signal detect and send the detected current signal to the operational amplifier 123. The operational amplifier 123 can low-pass filter the current signal and amplify the low-pass filtered current signal to obtain the error current signal and send the error current signal to the processing module 13.

The zero current converter 121 is connected in the power supply line of the load 30. When an electric shock or electrical leakage occurs in the power supply line of the load 30, the zero current converter 121 can detect the fault current in the power supply line of the load 30 to obtain a current signal for indicating the fault current. The current signal detected by the zero-current converter 121 includes high-frequency interference signals. And the current signal output from the zero-current converter 121 is a signal in the order of millivolts, that is, this current signal is relatively weak. Therefore, the current signal can be low-pass filtered by the operational amplifier 123 to filter out the high-frequency noise signals in the current signal; then the current signal is amplified to obtain a fault current signal identifiable by the processing module 13.

In the embodiments of the present application, a fault current in the power supply line of the load 30 is detected by the zero-current converter 121, obtaining a current signal for indicating the fault current, and the operational amplifier 123 low-pass filters and amplifies the current signal to obtain a fault current signal which is represented by the Processing module 13 can be identified, whereby the processing module 13 controls the tripping module 11 for tripping depending on the fault current signal, so that the tripping module 11 can trip in a timely manner if the power distribution system fails, thereby ensuring the safety of the power distribution.

It is understood that the operational amplifier 123 can realize both the function of a low-pass filter and the function of an amplifier circuit, so that the current signal can be low-pass filtered and amplified by the operational amplifier 123. The zero current transformer 121 may be a zero current transformer in the high frequency range to obtain residual currents from the load side. Therefore, the frequency of the fault current can reach 100 kHz or higher. The material of the zero current transformer can be a nanocrystalline material.

In one possible implementation, the processing module 13 may send a time-domain fault current, a frequency-domain fault current, and a trip log to the data collector via the communications module 14 so that the data collector can analyze the time-domain fault current, the frequency-domain fault current, and the trip log to determine an operating state of the power distribution system. The communication module 14 can also receive the configuration information sent by the data collector and send the configuration information to the processing module 13. The configuration information includes the target current as well as the operating frequency of the load and the cable length of the power supply line, etc. Thus, the processing module 13 can generate a trip curve or update the trip curve depending on the configuration information.

The communication module 14 can communicate with the data collector via WiFi, Bluetooth, ZigBee and other networks, which is not limited by the embodiments of the present application.

In a possible implementation includes, as in 6 shown, the residual current protection device 10 also has a display module 15. The display module 15 is connected to the processing module 13. The display module 15 can display operating modes and early warning information of the residual current protection device 10. A target leakage operating current (Idn), a delay time and an adaptive protection, etc. can also be configured by the display module 15.

The operating modes of the residual current protection device 10 include an adaptive mode, an upper limit mode, a lower limit mode and a standard mode. In the adaptive mode, the processing module 13 generates a trip curve and, depending on the generated trip curve, controls the trip module 11 to trip to realize type B adaptive protection. In the upper limit mode, depending on the upper limit trip curve, the processing module 13 controls the trip module 11 to trip to realize type B protection for the upper limit trip current curve. In the lower limit mode, depending on the lower limit trip curve, the processing module 13 controls the trip module 11 to trip to realize type B protection for the lower limit trip current curve. In standard mode, the processing module 13 controls the triggering module 11 for triggering based on the DIN VDE 0664-400: 2012 standard.

The display module 15 may include one or more indicator lights and buttons; or the display module 15 may include a touch screen for displaying relevant information and entering information.

In one possible implementation, the trigger module 11 may include a magnetic trigger mechanism.

In one possible implementation, the processing module includes 13, as in 6 shown, further an analog-to-digital converter 135, wherein after the residual current detection module 12 sends the residual current signal to the analog-to-digital converter 135, the analog-to-digital converter 135 converts the residual current signal from an analog signal to a digital signal and then sends the converted fault current signal to the digital filter unit 131, the upper limit detection unit 133 and the frequency range analysis unit 134.

Trigger control method

7 shows a flowchart of a method for trigger control according to an exemplary embodiment of the present application. The trip control method can be applied to the residual current protection device 10 described above. In particular, the trip control method can be carried out by the processing module 13 in the residual current protection device 10 described above. Unless otherwise stated, the residual current detection module in the following method embodiments may be the residual current detection module 12 in the embodiments described above, wherein the tripping module in the following method embodiments may be the tripping module 11 in the embodiments described above. As in 7 As shown, the trip control method 700 includes the following steps: Step 701: Obtaining a fault current signal detected by the fault current detection module, which is used to indicate a fault current in the load power supply line.

Step 702: Control the tripping module depending on the fault current signal and a tripping curve and in the case where the fault current at any frequency is greater than a corresponding tripping current threshold, so that the tripping module trips to disconnect the load's power supply line, the tripping curve being the Displaying a mapping between the frequency of the fault current and the tripping current threshold, and wherein the tripping curve is determined based on an inherent fault current of the power supply line.

In the exemplary embodiments of the present application, the tripping module is controlled for tripping depending on the residual current signal and the tripping curve. Since the trip curve is determined based on the inherent fault current of the load power supply line, a trip current threshold corresponding to the frequency of the inherent fault current on the trip curve is larger than the amplitude of the inherent fault current, which ensures that the inherent fault current of the load power supply line does not leads to the tripping of the tripping module, which reduces the incorrect actions of the residual current protection device and thus improves the stability of the power distribution.

In one possible implementation, the method 700 for tripping control further comprises: determining the inherent fault current of the power supply line depending on at least one parameter of a target current of the load, an operating frequency of the load and a cable length of the power supply line and generating the tripping curve depending on the inherent Fault current, such that a trip current threshold corresponding to the frequency of the inherent fault current on the trip curve is greater than the amplitude of the inherent fault current.

In a possible implementation, it is provided that the method 700 for tripping control further comprises: determining, depending on the fault current signal, whether a fault current corresponding to a preset target frequency is greater than a first current threshold, and controlling the tripping module in the case in which the fault current corresponding to the target frequency is greater than the first current threshold, so that the trip module trips, the first current threshold being smaller than a trip current threshold corresponding to the target frequency on the trip curve.

In a possible implementation, it is provided that when generating the tripping curve depending on the inherent fault current, the tripping curve can be generated depending on the inherent fault current and the preset upper limit tripping curve as well as the lower limit tripping curve, so that a tripping current threshold corresponding to any fault current frequency on the Tripping curve corresponds to between tripping current thresholds that correspond to this fault current frequency on the upper limit tripping curve and the lower limit tripping curve, respectively.

In one possible implementation, the tripping control method 700 further includes: updating the tripping curve after the tripping module is controlled to trip based on the determination that a fault current at any frequency is greater than the corresponding tripping current threshold, and increasing the tripping curve frequency corresponding Trip current threshold on the updated trip curve, wherein the trip current threshold corresponding to that frequency on the updated trip curve is less than a trip current threshold corresponding to that frequency on the high limit trip curve.

In one possible implementation, the trip control method 700 further comprises: determining a current amplitude obtained by superimposing fault currents with different frequencies, depending on the fault current signal; and controlling the tripping module in the event that the current amplitude is greater than a second current threshold so that the tripping module trips.

In one possible implementation, the trip control method 700 further includes: analyzing the fault current signal with respect to the frequency range, determining frequency information of a fault current that is greater than the corresponding trip current threshold, and sending the frequency information to the communication module.

It should be noted that the trip control method in the exemplary embodiments of the present application is carried out using the residual current protection device 10 in the exemplary embodiments described above. Since the details of the trip control method in the above-described embodiments of the residual current protection device have been described in detail with reference to the structural schematic views, regarding the specific process, reference can be made to the description in the above-described embodiments of the residual current protection device, which will not be repeated here.

Electricity distribution system

8th shows a schematic view of a power distribution system according to an embodiment of the present application. As in 8th As shown, the power distribution system 800 includes a power source 20, at least one load 30, and at least one residual current protection device 10 provided by one of the embodiments described above. An input of the residual current protection device 10 or each of the residual current protection devices is respectively connected to the power source 20, with an output of the residual current protection device 10 or each of the residual current protection devices being connected to the at least one load 30.

In the exemplary embodiments of the present application, each residual current protective device 10 is connected to one or more loads 30, the residual current protective device 10 or each of the residual current protective devices being respectively connected to the power source 20, the residual current protective device 10 depending on the residual current signal in the power supply line of the corresponding load 30 and the trip curve disconnects the power supply line of the load 30. Since the trip curve is determined based on the inherent fault current of the power supply line of the load 30, a trip current threshold corresponding to the frequency of the inherent fault current on the trip curve is larger than the amplitude of the inherent fault current, which ensures that the inherent fault current of the power supply line of the load does not lead to the tripping of the tripping module, which reduces the incorrect actions of the residual current protection device and thus improves the stability of the power distribution.

In a possible implementation includes, as in 8th shown, the power distribution system 800 further includes a data collector 40. The data collector 40 may communicate with the residual current protection device 10 or each of the residual current protection devices via a wired network or a wireless network to receive frequency information sent from the residual current protection device 10 or the residual current protection devices and Depending on the frequency information, the cause of the tripping of the residual current protective devices 10 is analyzed.

In the embodiments of the present application, the data collector 40 may receive the frequency information sent from the residual current protection device 10 or the residual current protection devices. Since the frequencies of the fault currents generated by different types of failures in the power distribution system are different, by analyzing the frequency information, the data collector can determine the type of failure that causes the residual current device to trip, thereby facilitating the recovery of the power distribution system failure and the user experience is improved.

It is understood that the data collector 40 may be a local server or a cloud server. The communication between the data collector 40 and the residual current protection device 10 can take place via wireless networks such as Bluetooth, WiFi, ZigBee, 5G, 4G, etc. or via wired networks such as fiber optic and broadband.

Electronic device

9 shows a schematic view of an electronic device provided by an embodiment of the present application. However, the specific embodiments of the present application do not limit the specific implementation of the electronic device. With reference to 9 The electronic device 900 provided by the embodiment of the present application includes: a processor 902, a communication interface 904, a memory 906 and a communication bus 908.

The processor 902, the memory 906 and the communication interface 904 communicate with each other via the communication bus 908.

The communication interface 904 is used to communicate with other electronic devices or servers.

The processor 902 is used to execute a program 910 and in particular can execute the relevant steps of the trigger control method according to one of the exemplary embodiments described above.

In particular, the program 910 may include program codes containing computer-operated instructions.

The processor 902 may be a central processing unit CPU or an application specific integrated circuit (ASIC), or is configured to execute one or more integrated circuits of the embodiments of the present application. One or more processors included in an intelligent device may be a process of the same type, such as one or more CPUs; Processors of different types are also possible, such as one or more CPUs and one or more ASICs.

Memory 906 is used to store program 910. The memory 906 may include high-speed RAM memory and may also include non-volatile memory such as at least one disk memory.

Program 910 may be used specifically to cause processor 902 to execute the trigger control method in any of the embodiments described above.

Regarding the specific implementation of the individual steps in the program 910, reference can be made to the corresponding description of the respective steps and units in one of the exemplary embodiments of the trigger control method described above, which is not repeated here. The person skilled in the art can clearly understand that for the sake of simplicity and conciseness of the description, the specific working processes of the device and the module described above can refer to the corresponding processes in the method embodiments described above, which is not repeated here.

The electronic device of the exemplary embodiment of the present application controls the tripping module for tripping depending on the residual current signal and the tripping curve. Since the trip curve is determined based on the inherent fault current of the load power supply line, a trip current threshold corresponding to the frequency of the inherent fault current on the trip curve is larger than the amplitude of the inherent fault current, which ensures that the inherent fault current of the load power supply line does not leads to the tripping of the tripping module, which reduces the incorrect actions of the residual current protection device and thus improves the stability of the power distribution.

Computer-readable storage medium

An embodiment of the present application further provides a computer-readable storage medium storing instructions that cause a machine to perform the trigger control method herein. In particular, a system or device may be provided equipped with a storage medium on which the software program codes for realizing the functions in one of the embodiments described above are stored, wherein a computer (or CPU or MPU) of the system or device stores the software program codes on the storage medium reads and executes stored program codes.

In this case, the program codes read from the storage medium can themselves realize the function of one of the exemplary embodiments described above, so that the program codes and the storage medium on which the program codes are stored form part of the present application.

Examples of storage media for providing program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards and ROMs. Optionally, the program codes can be downloaded from a server computer via a communications network.

In addition, it should be understood that not only by executing the program codes read by the computer, but also by an operating system running on the computer based on the instructions of the program codes, some or all of the actual operations can be completed, thereby making the functions in one of the exemplary embodiments described above are realized.

In addition, it is understood that the program codes read from the storage medium are written into a memory which is provided in an expansion board inserted into the computer or in an expansion module connected to the computer, the CPU then being installed on the expansion board or the expansion module is, based on the instructions of the program codes, performs some or all of the actual operations, thereby realizing the functions in any of the embodiments described above.

Computer program product

The embodiments of the present application further provide a computer program product that is physically stored on a computer-readable medium and includes computer-executable instructions, the computer-executable instructions, when executed, causing at least one processor to perform the trigger control method provided in the individual embodiments above. It is understood that the individual solutions in the present exemplary embodiment have corresponding technical effects in the above method exemplary embodiments, which is not repeated here.

It should be noted that in the above flows or structural views of the system, not all steps and modules are necessary, although some steps or modules can be ignored as necessary. The order in which each step is performed is not fixed and can be adjusted as needed. The system structures described in the individual exemplary embodiments above can be physical structures or logical structures. That is, some modules can be realized by the same physical entity; alternatively, some modules may be realized by multiple physical entities or may be jointly realized by some components in multiple independent devices.

In the individual exemplary embodiments above, hardware modules can be implemented mechanically or electrically. For example, a hardware module may contain permanent dedicated circuitry or logic (such as a dedicated processor, FPGA, or ASIC) to perform the corresponding operations. The hardware module may also include programmable logic or circuitry (such as a general purpose processor or other programmable processor) and may also be temporarily adjustable by software to perform corresponding operations. The specific implementation method (mechanical implementation or permanent dedicated circuit or temporary set circuit) can be determined based on cost and time considerations.

The present application is presented and indicated in detail above by the accompanying drawings and the preferred exemplary embodiments. However, the present application is not limited to these disclosed embodiments. Based on the above-mentioned several embodiments, those skilled in the art will know that more embodiments of the present application can be obtained by combining the code verification measures in the above-mentioned different embodiments, and these obtained embodiments are also included within the scope of the present application.

Reference symbol list

10

Residual current protection device

11

Trigger module

12

Residual current detection module

13

Processing module

14

Communication module

15

Display module

20

power source

30

load

40

Data collector

121

zero current transformer

122

excitation circuit

123

operational amplifier

135

Analog-to-digital converter

131

digital filter unit

132

Trigger control unit

133

Upper limit detection unit

134

Unit for analyzing frequency ranges

301

Upper limit trip curve

302

Lower limit trip curve

303

Standard trip curve

700

Trigger control method

701

Obtaining a residual current signal detected by the residual current detection module

702

Controlling the trip module to trip in the event that the fault current at any frequency is greater than a corresponding trip current threshold

800

Electricity distribution system

900

Electronic device

902

processor

904

Communication interface

906

Storage

908

Communication bus

910

program

Claims (20)

Residual current protection device (10), comprising a tripping module (11), a residual current detection module (12) and a processing module (13), wherein the tripping module (11) is connected between a power source (20) and a load (30), the residual current detection module (12) being connected in a power supply line between the tripping module (11) and the load (30); wherein the fault current detection module (12) is adapted to detect a fault current signal used to indicate a fault current in the power supply line of the load (30) and to send the fault current signal to the processing module (13); and wherein the processing module (13) is adapted to control the tripping module (11) so that it trips, depending on the fault current signal and a tripping curve in the event that the fault current at any frequency is greater than a corresponding tripping current threshold value to disconnect the power supply line of the load (30), wherein the trip curve is used to indicate a relationship between the frequency of the fault current and the trip current threshold, and wherein the trip curve is determined based on an inherent fault current of the power supply line. Residual current protection device (10). Claim 1 , wherein the processing module (13) comprises a digital filter unit (131) and a trip control unit (132), the digital filter unit (131) being used depending on at least one parameter from a target current of the load (30), an operating frequency of the load (30) and a cable length of the power supply line to determine the inherent fault current of the power supply line, and depending on the inherent fault current to generate the tripping curve, so that a tripping current threshold corresponding to the frequency of the inherent fault current on the tripping curve is greater than the amplitude of the inherent fault current is; and wherein the tripping control unit (132) is used to control the tripping module (11) to trip depending on the fault current signal and the tripping curve in the event that the fault current at any frequency is greater than a corresponding tripping current threshold. Residual current protection device (10). Claim 2 , wherein the trip control unit (132) is used to determine, depending on the fault current signal, whether a fault current corresponding to a preset target frequency is greater than a first current threshold, in the case in which the fault current corresponding to the target frequency is greater than the first current threshold, to control the tripping module (11) so that it trips, and wherein the first current threshold is less than a tripping current threshold corresponding to the target frequency on the tripping curve. Residual current protection device (10). Claim 2 or 3 , wherein the digital filter unit (131) is used to generate the tripping curve depending on the inherent fault current and a preset upper limit tripping curve and lower limit tripping curve, so that a tripping current threshold value which corresponds to any fault current frequency on the tripping curve lies between tripping current threshold values, which correspond to this fault current frequency on the upper limit trip curve or the lower limit trip curve. Residual current protection device (10). Claim 4 , wherein the digital filter unit (131) is used to control the tripping curve after the tripping control unit (132) has controlled the tripping module (11) to trip due to a fault current at any frequency greater than the corresponding tripping current threshold value update and increase the trip current threshold corresponding to that frequency on the updated trip curve, wherein the trip current threshold corresponding to that frequency on the updated trip curve is less than a trip current threshold corresponding to that frequency on the upper limit trip curve. Residual current protection device (10). Claim 2 , wherein the processing module (13) comprises an upper limit detection unit (133), the upper limit detection unit (133) being used to determine, depending on the fault current signal, a current amplitude, which is obtained by superimposing fault currents with different frequencies, and the send current amplitude to the trip control unit (132); and wherein the trip control unit (132) is used to control the trip module (11) to trip in the event that the current amplitude is greater than a second current threshold. Residual current protection device (10) according to one of the Claims 1 until 6 , wherein the residual current protection device (10) further comprises a communication module (14), the processing module (13) further comprising a unit for analyzing frequency ranges (134); wherein the frequency range analysis unit (134) analyzes the fault current signal with respect to the frequency range, determines frequency information of a fault current greater than the corresponding trip current threshold, and sends the frequency information to the communication module (14); and wherein the communication module (14) is used to send the frequency information to a data collector (40). Residual current protection device (10) according to one of the Claims 1 until 6 , wherein the fault current detection module (12) comprises a zero current converter (121), an excitation circuit (122) and an operational amplifier (123); wherein the zero current transformer (121) is connected in the power supply line between the tripping module (11) and the load (30), the zero current transformer (121) being connected to the excitation circuit (122) and the operational amplifier (123), respectively; wherein the excitation circuit (122) is used to provide an excitation signal to the zero current converter (121); wherein the zero current converter (121) is used to detect the fault current in the power supply line of the load (30) based on the excitation signal and send a detected current signal to the operational amplifier (123); and wherein the operational amplifier (123) is used to low-pass filter the current signal and amplify the low-pass filtered current signal to obtain the error current signal and send the error current signal to the processing module (13). Method (700) for triggering control for a residual current protection device (10), the residual current protection device (10) comprising a tripping module (11) and a residual current detection module (12), the tripping module (11) being connected between a power source (20) and a load (30). is connected, wherein the residual current detection module (12) is connected in a power supply line between the tripping module (11) and the load (30), the method comprising: obtaining a fault current signal detected by the fault current detection module (12) which is used to indicate a fault current in the power supply line of the load (30); and Controlling the trip module (11) depending on the fault current signal and a trip curve and in the case where the fault current at any frequency is greater than a corresponding trip current threshold, so that the trip module trips to disconnect the power supply line of the load (30), wherein the trip curve is used to indicate a relationship between the frequency of the fault current and the trip current threshold, and wherein the trip curve is determined based on an inherent fault current of the power supply line. Procedure according to Claim 9 , wherein the method further comprises: determining the inherent fault current of the power supply line depending on at least one parameter from a target current of the load (30), an operating frequency of the load (30) and a cable length of the power supply line and generating the tripping curve depending on the inherent fault current, so that a trip current threshold corresponding to the frequency of the inherent fault current on the trip curve is greater than the amplitude of the inherent fault current. Procedure according to Claim 10 , wherein the method further comprises: determining, depending on the fault current signal, whether a fault current corresponding to a preset target frequency is greater than a first current threshold, and controlling the tripping module (11) in the case in which the fault current corresponding to the target frequency is greater than the first current threshold , so that the tripping module trips, the first current threshold being less than a tripping current threshold corresponding to the target frequency on the tripping curve. Procedure according to Claim 10 , wherein generating the tripping curve depending on the inherent fault current includes: generating the tripping curve depending on the inherent fault current and a preset upper limit tripping curve and lower limit tripping curve such that a tripping current threshold corresponding to any fault current frequency on the tripping curve is between tripping current thresholds, which correspond to this fault current frequency on the upper limit trip curve or the lower limit trip curve. Procedure according to Claim 12 , the method further comprising: updating the tripping curve after the tripping module (11) has been controlled to trip based on the determination that a fault current at any frequency is greater than the corresponding tripping current threshold, and increasing the tripping current threshold corresponding to that frequency to the updated one Trip curve, wherein the trip current threshold corresponding to that frequency on the updated trip curve is less than a trip current threshold corresponding to that frequency on the high limit trip curve. Procedure according to Claim 10 , the method further comprising: determining a current amplitude obtained by superimposing fault currents with different frequencies depending on the fault current signal; and controlling the trip module (11) in the event that the current amplitude is greater than a second current threshold so that the trip module trips. Procedure according to one of the Claims 9 until 14 , the method further comprising: analyzing the fault current signal with respect to the frequency range, determining frequency information of a fault current that is greater than the corresponding trip current threshold, and sending the frequency information to the communication module (40). Power distribution system (800), comprising a power source (20), at least one load (30) and at least one residual current protection device (10) according to one of Claims 1 until 8th , wherein an input of the residual current protection device or each of the residual current protection devices (10) is connected to the power source (20); and wherein an output of the residual current protection device or each of the residual current protection devices (10) is connected to the at least one load (30). Power distribution system Claim 16 , wherein the power distribution system further comprises a data collector (40); wherein the data collector (40) communicates with the residual current protection device or each of the residual current protection devices (10) via a wired network or a wireless network to receive frequency information sent by the residual current protection device or the residual current protection devices (10) and depending on the frequency information to analyze the cause of the tripping of the residual current protective devices (10). Electronic device, electronic device (900), comprising a processor (902), a communication interface (904), a memory (906) and a communication bus (908), the processor (902), the memory (906) and the communication interface ( 904) communicate with each other via the communication bus (908); and wherein the memory (906) is used to store at least one executable instruction that causes the processor (902) to execute the steps corresponding to the trigger control method (700) according to one of Claims 9 until 15 correspond to carry out. A computer-readable storage medium on which computer instructions are stored, the computer instructions, when executed by a processor, causing that processor to perform the method according to one of the Claims 9 until 15 to carry out. Computer program product materially stored on a computer-readable medium and comprising computer-executable instructions, the computer-executable instructions, when executed, causing at least one processor to perform the method according to one of the Claims 9 until 15 to carry out.

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