Current protection device and current detection method

Abstract

The embodiment of the present application provides a current protection device and a current detection method. The current protection device includes a magnetic ring, a magnetic modulation circuit and a magnetic modulation state detection module, wherein the magnetic ring is suitable for allowing at least one conductor through which the current to be measured can pass, the magnetic modulation circuit includes a coil and a magnetic modulation drive module and is suitable for generating an oscillation waveform on the coil, the coil is wound on the magnetic ring, the magnetic modulation drive module is connected to the coil, the magnetic modulation state detection module is connected to the magnetic modulation circuit, and is suitable for determining the working state of the magnetic modulation circuit by detecting the oscillation waveform, wherein when the working state is abnormal, the magnetic modulation state detection module outputs a wake-up signal to the magnetic modulation circuit. The magnetic modulation drive module can perform a wake-up operation based on the wake-up signal, so that the magnetic ring can be restored to a normal working state in a timely manner after stopping oscillation due to an instantaneous or non-continuous large current.

Description

Technical Field

[0001] The present invention relates to the field of current protection, and in particular to a current protection device and a current detection method based on magnetic modulation. Background Art

[0002] In AC or DC power supply systems, isolation is usually used to detect the current in the power supply line. For example, magnetic modulation technology is used to detect the residual current in the AC power supply line; when the residual current is detected to be greater than the set threshold, the power supply line and the load are disconnected, thereby protecting the load and personnel.

[0003] However, when a surge current is generated or the measured current is very large, the measured current may generate a large enough magnetic field to keep the magnetic ring used for magnetic modulation in a magnetic saturation state and unable to exit, thereby failing to generate a magnetic modulation carrier signal, making the detection of the measured current ineffective. Summary of the invention

[0004] The technical problem solved by the present invention is that the magnetic ring used for magnetic modulation is always in a magnetic saturation state and cannot exit.

[0005] To solve the above technical problems, an embodiment of the present invention provides a current protection device, comprising: a magnetic ring, which is suitable for allowing at least one conductor through which the current to be measured can pass; a magnetic modulation circuit, which includes a coil and a magnetic modulation drive module and is suitable for generating an oscillating waveform on the coil, wherein the coil is wound on the magnetic ring and the magnetic modulation drive module is connected to the coil; a magnetic modulation state detection module, which is connected to the magnetic modulation circuit and is suitable for determining the working state of the magnetic modulation circuit by detecting the oscillating waveform, wherein when the working state is abnormal, the magnetic modulation state detection module outputs a wake-up signal to the magnetic modulation circuit.

[0006] Optionally, the magnetic modulation state detection module is adapted to determine the working state of the magnetic modulation circuit by detecting the frequency or duty cycle of the oscillation waveform.

[0007] Optionally, when the frequency of the detected oscillation waveform is less than 300 Hz, the frequency is greater than 100 KHz, the duty cycle is less than 25%, or the duty cycle is greater than 75%, it is determined that the working state is abnormal.

[0008] Optionally, the magnetic modulation state detection module is adapted to output a wake-up signal to the magnetic modulation circuit, and the wake-up signal is adapted to enable the magnetic modulation circuit to perform a wake-up operation.

[0009] Optionally, the wake-up signal includes a first wake-up signal, the wake-up operation includes a first wake-up operation, and the magnetic modulation circuit is suitable for performing the first wake-up operation based on the first wake-up signal to generate a first magnetic modulation drive signal applied to the magnetic ring, which is opposite to the direction of the second magnetic modulation drive signal that causes the magnetic ring to enter the most recent magnetic saturation state.

[0010] Optionally, a time width of the first wake-up operation is greater than half of a period of the oscillation waveform.

[0011] Optionally, the wake-up signal includes a second wake-up signal, the wake-up operation includes a second wake-up operation, and the magnetic modulation circuit is adapted to perform the second wake-up operation based on the second wake-up signal after performing the first wake-up operation to generate a third magnetic modulation drive signal applied to the magnetic ring.

[0012] Optionally, the wake-up signal includes a third wake-up signal, the wake-up operation includes a third wake-up operation, and the magnetic modulation circuit is adapted to perform the third wake-up operation based on the third wake-up signal to generate a high-frequency oscillation signal with a gradually decreasing amplitude applied to the magnetic ring.

[0013] Optionally, the frequency of the high-frequency oscillation signal gradually increases from 2 KHz to 100 KHz, and the amplitude gradually decreases from the power supply voltage to zero.

[0014] Optionally, the wake-up signal includes a fourth wake-up signal, the wake-up operation includes a fourth wake-up operation, and the magnetic modulation circuit is adapted to perform the fourth wake-up operation based on the fourth wake-up signal after performing the third wake-up operation to generate a fourth magnetic modulation drive signal applied to the magnetic ring.

[0015] Optionally, the current protection device further comprises a tripping module, wherein: the magnetic modulation state detection module is adapted to output a tripping signal when detecting that the working state is abnormal; the tripping module is connected to the magnetic modulation state detection module and is adapted to perform a disconnection operation on the conductor based on the tripping signal.

[0016] Optionally, the current protection device also includes a tripping module, wherein: the magnetic modulation state detection module is suitable for outputting a tripping signal when the working state is still abnormal after the magnetic modulation circuit performs a wake-up operation; the tripping module is connected to the magnetic modulation state detection module and is suitable for performing a disconnection operation on the conductor based on the tripping signal.

[0017] Optionally, the current protection device also includes: a demodulation module, which is connected to the magnetic modulation drive module and is suitable for demodulating the oscillation waveform to generate a demodulation signal; a current detection module, which is connected to the demodulation module and is suitable for detecting the demodulation signal, and outputting a tripping signal when the effective value or peak value of the electrical parameter in the demodulation signal reaches a set threshold; and a tripping module, which is connected to the current detection module and is suitable for performing a disconnection operation on the conductor based on the tripping signal.

[0018] An embodiment of the present invention also provides a current detection method, including: step a, detecting the working state of the magnetic modulation circuit; step b, determining whether the working state is abnormal, and if so, outputting a wake-up signal; step c, performing a wake-up operation based on the wake-up signal.

[0019] Optionally, the wake-up signal includes a first wake-up signal, the wake-up operation includes a first wake-up operation, and the magnetic modulation circuit performs the first wake-up operation based on the first wake-up signal to generate a first magnetic modulation drive signal applied to the magnetic ring, which is opposite to the direction of the second magnetic modulation drive signal that causes the magnetic ring to enter the most recent magnetic saturation state.

[0020] Optionally, the wake-up signal includes a second wake-up signal, the wake-up operation includes a second wake-up operation, and the magnetic modulation circuit performs the second wake-up operation based on the second wake-up signal after performing the first wake-up operation to generate a third magnetic modulation drive signal applied to the magnetic ring.

[0021] Optionally, the wake-up signal includes a third wake-up signal, the wake-up operation includes a third wake-up operation, and the magnetic modulation circuit performs the third wake-up operation based on the third wake-up signal to generate a high-frequency oscillation signal with a gradually decreasing amplitude applied to the magnetic ring.

[0022] Optionally, the wake-up signal includes a fourth wake-up signal, the wake-up operation includes a fourth wake-up operation, and the magnetic modulation circuit performs the fourth wake-up operation based on the fourth wake-up signal after performing the third wake-up operation to generate a fourth magnetic modulation drive signal applied to the magnetic ring.

[0023] Optionally, the method includes: if the working state does not become normal, looping steps a, b and c for a total of N times, where N is an integer greater than or equal to 1.

[0024] Optionally, the method includes: determining whether the number of executions of the cycle exceeds N times, and if so, outputting a trip signal; and performing a disconnection operation on the conductor based on the trip signal.

[0025] Compared with the prior art, the technical solution of the embodiment of the present invention has beneficial effects.

[0026] For example, when the working state of the magnetic modulation circuit is abnormal, the magnetic modulation state detection module outputs a wake-up signal to the magnetic modulation driving module, and the magnetic modulation driving module can perform a wake-up operation based on the wake-up signal, so that the magnetic ring can be restored to a normal working state in time after stopping vibration due to instantaneous or non-continuous large current.

[0027] For another example, when the working state of the magnetic modulation circuit is abnormal, at least one wake-up operation can be performed and the working state of the magnetic modulation circuit can be detected after each wake-up operation. If it is detected that the working state of the magnetic modulation circuit is still abnormal after performing a predetermined number of wake-up operations, a trip signal is output and the conductor is disconnected. By setting the predetermined number of times, when it is difficult to judge in advance whether the magnetic ring can be restored to a normal working state during a stop vibration caused by a large current (such as an instantaneous large current, a non-continuous large current, and a continuous large current), the possibility of restoring to a normal state and the timeliness of the need for tripping due to the inability to restore to a normal state are taken into account. That is, a trial wake-up is performed to improve the anti-interference ability of the current protection device, and a tripping operation is performed in time to avoid safety hazards when it is determined that it is difficult to wake up (that is, it is difficult to restore the magnetic ring from a stop vibration state to a normal working state). BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a current protection device according to an embodiment of the present invention;

[0029] Figure 2 It is a curve diagram of magnetic induction intensity and magnetic field intensity on a magnetic ring in the prior art;

[0030] Figure 3 is a schematic diagram of a high frequency oscillation signal according to an embodiment of the present invention;

[0031] Figure 4 is another structural schematic diagram of the current protection device according to an embodiment of the present invention;

[0032] Figure 5 It is another structural schematic diagram of the current protection device according to the embodiment of the present invention;

[0033] Figure 6 is a schematic diagram of the specific structure of the current protection device according to an embodiment of the present invention;

[0034] Figure 7 It is a schematic diagram of waveforms of relevant parameters in the vibration stop caused by instantaneous large current in an embodiment of the present invention;

[0035] Figure 8 It is a schematic diagram of the waveforms of relevant parameters in the case of oscillation stop caused by a continuous large current in an embodiment of the present invention;

[0036] Fig. 9 is a first flow chart of the current detection method according to an embodiment of the present invention;

[0037] Fig.10 This is a second flow chart of the current detection method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] When describing the embodiments of the present invention in conjunction with specific drawings, the elements represented by the same figure marks in the drawings, such as magnetic rings, conductors, coils, modules, circuits and switches, are the same elements and have the same functions and connection relationships.

[0039] In an embodiment of the present invention, the connection includes an electrical connection for transmitting electrical parameters between different elements, and a signal connection for transmitting electrical signals between different elements.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0041] Figure 1 The current protection device 100 according to an embodiment of the present invention is illustrated, and includes a magnetic ring 110 , a magnetic modulation circuit 120 and a magnetic modulation state detection module 130 .

[0042] The magnetic ring 110 is a closed-shaped magnetic conductor, through which at least one conductor 140 through which a current to be measured can pass passes. The current to be measured can be a direct current or an alternating current.

[0043] There may be one conductor 140 passing through the magnetic ring 110 , and the current protection device 100 may detect current changes on the one conductor.

[0044] There may be more than one conductor 140 passing through the magnetic ring 110, for example, two conductors in a DC circuit (a power line and a ground line), two conductors in an AC circuit (two phase lines), three conductors in an AC circuit (three phase lines), and four conductors in an AC circuit (three phase lines and a neutral line). In an AC circuit, the vector sum of the currents passing through each conductor is a residual current, and the current protection device 100 can detect the residual current.

[0045] The magnetic modulation circuit 120 includes a coil 121 and a magnetic modulation driving module 122 , wherein the coil 121 is wound on the magnetic ring 110 , and the magnetic modulation driving module 122 is connected to the coil 121 .

[0046] The magnetic modulation driving module 122 is connected to a voltage source or a current source, so that a magnetic modulation driving signal can be provided; the magnetic modulation driving module 122 also forms an oscillation circuit with the coil 121, so as to provide the magnetic modulation driving signal to the coil 121, so that a periodically changing magnetic field intensity is induced on the magnetic ring 110 surrounded by the coil 121, thereby generating an oscillation waveform on the coil 121 (which can be called a magnetic modulation oscillation signal or a basic oscillation waveform, which is an unmodulated oscillation waveform in this case).

[0047] like Figure 2As shown, the magnetic induction intensity B changes periodically with the magnetic field intensity H generated by the magnetic modulation drive signal, and the closed curve formed is a hysteresis loop. When the magnetic field intensity H is positive, the magnetic induction intensity B has a positive magnetic saturation state a, and when it is negative, the magnetic induction intensity B has a negative magnetic saturation state b.

[0048] Specifically, when the magnetic field strength H is not applied and the magnetic induction strength B in the magnetic ring 110 is zero, the magnetic field strength H is gradually increased from the origin o in the positive direction. Accordingly, the magnetic induction strength B increases along Figure 2 The oca curve in the figure also gradually increases until it reaches the magnetic saturation state a. At this time, when the magnetic field strength H is increased, the magnetic induction intensity B remains basically unchanged; when it just reaches the magnetic saturation state a, the value of the magnetic field strength H is represented by +Hs, and the magnetic induction intensity B is represented by +Bs.

[0049] At this time, if the magnetic field strength H is reduced in the reverse direction, the magnetization curve does not return along the original oca curve from point a; when the magnetic field strength H is reduced to zero, the magnetic induction intensity is +Br; continue to apply the reverse magnetic field strength H, when it reaches -Hc, the magnetic induction intensity B is zero; then apply the reverse magnetic field strength H, when it reaches -Hs, the magnetic induction intensity B is -Bs, that is, it reaches the reverse magnetic saturation state b.

[0050] At this time, if the magnetic field strength H is increased in the positive direction, when the magnetic field strength H increases to zero, the magnetic induction intensity is -Br; continue to apply the positive magnetic field strength H, when it reaches +Hc, the magnetic induction intensity B is zero; then apply the positive magnetic field strength H, when it reaches +Hs, the magnetic induction intensity B is +Bs, that is, it returns to the positive magnetic saturation state a.

[0051] Continue to refer Figure 1 The magnetic modulation circuit 120 may include a coil, and the magnetic modulation driving module 122 includes a driving pin and a sensing pin respectively connected to two ends of the coil.

[0052] The magnetic modulation circuit 120 may include two coils, namely a first coil and a second coil, and the magnetic modulation driving module 122 includes a first driving pin and a first sensing pin respectively connected to both ends of the first coil, and a second driving pin and a second sensing pin respectively connected to both ends of the second coil.

[0053] The magnetic modulation state detection module 130 is connected to the magnetic modulation circuit 120 through a line, and can receive the signal input by the magnetic modulation circuit 120 through the line to detect the oscillation waveform, and then determine the working state of the magnetic modulation circuit 120; the magnetic modulation state detection module 130 can output a wake-up signal to the magnetic modulation circuit 120 through the above-mentioned line or other lines.

[0054] By passing the conductor 140 of the current to be measured through the magnetic ring 110, the characteristics of the oscillation waveform on the coil can be changed, that is, the signal of the current to be measured is modulated on the oscillation waveform to form a modulated wave (which can be called a modulated oscillation waveform). The oscillation waveform can be detected, for example, by filtering out the basic oscillation waveform with a higher frequency than the modulated wave through a high-order low-pass filter, so as to determine whether a large current passes through the conductor 140, and then determine the working state of the magnetic modulation circuit 120.

[0055] The working state of the magnetic modulation circuit 120 can be determined by calculating the frequency or duty cycle of the oscillation waveform. For example, the frequency or duty cycle of the oscillation waveform can be calculated by detecting the rising edge or falling edge of the pin at which the magnetic modulation state detection module 130 is connected to the magnetic modulation circuit 120.

[0056] In one embodiment, when the frequency of the detected oscillation waveform is less than 300 Hz, the frequency is greater than 100 KHz, the duty cycle is less than 25%, or the duty cycle is greater than 75%, the working state is determined to be abnormal.

[0057] When the working state of the magnetic modulation circuit 120 is abnormal, the large current flowing through the conductor 140 will cause the magnetic ring 110 to be in a magnetic saturation state (for example, Figure 2 In the forward magnetic saturation state a or the reverse magnetic saturation state b) shown, at this time, the magnetic field strength generated by the magnetic modulation driving signal of the magnetic modulation driving module 122 cannot make the magnetic ring 110 exit the magnetic saturation state, so that an oscillation waveform cannot be generated.

[0058] When the working state of the magnetic modulation circuit 120 is abnormal, the output waveform of the magnetic modulation circuit 120 detected by the magnetic modulation state detection module 130 may be a direct current waveform or a higher frequency oscillation waveform.

[0059] When an abnormal working state is detected, the magnetic modulation state detection module 130 may output a wake-up signal to the magnetic modulation circuit 120 .

[0060] Specifically, the magnetic modulation state detection module 130 may output a wake-up signal to the magnetic modulation circuit 120 , and the magnetic modulation circuit 120 may perform a wake-up operation after receiving the wake-up signal.

[0061] In a specific implementation, the wake-up signal may include a first wake-up signal, and the wake-up operation may include a first wake-up operation. The magnetic modulation circuit 120 may perform the first wake-up operation based on the first wake-up signal to generate a first magnetic modulation drive signal applied to the magnetic ring 110, which is opposite to the direction of the second magnetic modulation drive signal that causes the magnetic ring 110 to enter the most recent magnetic saturation state, so that the magnetic ring 110 may exit the magnetic saturation state, that is, enter the non-magnetic saturation state from the magnetic saturation state.

[0062] The time width of the first wake-up operation can be greater than half of the period of the oscillation waveform, so that the magnetic modulation circuit 120 has enough time to apply the first magnetic modulation drive signal in the opposite direction to the second magnetic modulation drive signal, thereby making it more likely that the magnetic ring 110 will exit the magnetic saturation state.

[0063] In one embodiment, the magnetic modulation state detection module 130 outputs a first wake-up signal to the magnetic modulation driving module 122; after receiving the first wake-up signal, the magnetic modulation driving module 122 applies a first magnetic modulation driving signal to the coil 121 wound on the magnetic ring 110. Driven by the first magnetic modulation driving signal, the magnetic ring 110 may enter a non-magnetic saturation state from a magnetic saturation state, wherein the first magnetic modulation driving signal is opposite in direction to the second magnetic modulation driving signal that causes the magnetic ring 110 to enter the most recent magnetic saturation state.

[0064] In another embodiment, the magnetic modulation state detection module 130 outputs a first wake-up signal to the coil 121; after receiving the first wake-up signal, the coil 121 applies a first magnetic modulation drive signal to the magnetic ring 110 wound by it, and driven by the first magnetic modulation drive signal, the magnetic ring 110 may enter a non-magnetic saturation state from a magnetic saturation state, wherein the first magnetic modulation drive signal is opposite in direction to the second magnetic modulation drive signal that causes the magnetic ring 110 to enter the most recent magnetic saturation state.

[0065] In a specific implementation, the wake-up signal may further include a second wake-up signal, and the wake-up operation may include a second wake-up operation. After performing the first wake-up operation, the magnetic modulation circuit 120 may perform a second wake-up operation based on the second wake-up signal to generate a third magnetic modulation driving signal applied to the magnetic ring 110 .

[0066] In one embodiment, after the first wake-up operation is performed, the magnetic modulation state detection module 130 outputs a second wake-up signal to the magnetic modulation driving module 122; after receiving the second wake-up signal, the magnetic modulation driving module 122 applies a third magnetic modulation driving signal to the coil 121 wound on the magnetic ring 110. If the magnetic ring 110 has entered the non-magnetic saturation state from the magnetic saturation state, then under the drive of the third magnetic modulation driving signal, the magnetic ring 110 will operate normally along the hysteresis loop and generate an oscillating waveform on the coil 121. Then, the working state of the magnetic modulation circuit 120 can be detected. If it is normal, the magnetic ring 110 can be driven by the magnetic modulation driving signal generated by the magnetic modulation driving module 122 to form an oscillating waveform on the coil 121.

[0067] In another embodiment, after the first wake-up operation is performed, the magnetic modulation state detection module 130 outputs a second wake-up signal to the coil 121; after receiving the second wake-up signal, the coil 121 applies a third magnetic modulation drive signal to the magnetic ring 110 wound by it, and if the magnetic ring 110 has entered the non-magnetic saturation state from the magnetic saturation state, then under the drive of the third magnetic modulation drive signal, the magnetic ring 110 will operate normally along the hysteresis loop to generate an oscillating waveform on the coil 121. Then, the working state of the magnetic modulation circuit 120 can be detected, and if it is normal, the magnetic ring 110 can be driven by the magnetic modulation drive signal generated by the magnetic modulation drive module 122 to form an oscillating waveform on the coil 121.

[0068] The second wake-up signal may have the same direction as or an opposite direction to the first wake-up signal.

[0069] The first wake-up signal may only cause the magnetic ring 110 to just leave the magnetic saturation state. If a second signal with the same direction as the first signal is applied immediately, the magnetic ring 110 may enter the magnetic saturation state again and cannot exit. Therefore, in a preferred embodiment, the second wake-up signal is in the opposite direction to the first wake-up signal, and the magnetic ring 110 will deviate from the magnetic saturation state it just left and move towards another magnetic saturation state, thereby increasing the possibility of wake-up.

[0070] In a specific implementation, the wake-up signal may include a third wake-up signal, and the wake-up operation may include a third wake-up operation. The magnetic modulation circuit 120 may perform a third wake-up operation based on the third wake-up signal to generate a high-frequency oscillation signal with a gradually decreasing amplitude applied to the magnetic ring 110 .

[0071] like Figure 2 As shown in the figure, when the amplitude of the high-frequency oscillation signal applied to the magnetic ring 110 gradually decreases, the magnetic field intensity H generated by the high-frequency oscillation signal gradually decreases, and the magnetic induction intensity B induced by the magnetic field intensity H also gradually decreases, that is, gradually moves toward the origin o. In this process, the magnetic ring 110 may exit the magnetic saturation state, that is, enter the non-magnetic saturation state from the magnetic saturation state.

[0072] like Figure 3 As shown, the frequency of the high-frequency oscillation signal applied to the magnetic ring 110 can gradually increase from 2KHz to 100KHz, and the amplitude can gradually decrease from the power supply voltage, such as 5V, to zero, wherein the power supply voltage can be the power supply voltage provided to the magnetic modulation circuit 120.

[0073] In one of the embodiments, the magnetic modulation state detection module 130 outputs a third wake-up signal to the magnetic modulation driving module 122; after receiving the third wake-up signal, the magnetic modulation driving module 122 applies a high-frequency oscillation signal with a gradually decreasing amplitude to the coil 121 wound on the magnetic ring 110. Driven by the high-frequency oscillation signal, the magnetic ring 110 may enter a non-magnetic saturation state from a magnetic saturation state.

[0074] In another embodiment, the magnetic modulation state detection module 130 outputs a third wake-up signal to the coil 121; after receiving the third wake-up signal, the coil 121 applies a high-frequency oscillation signal with a gradually decreasing amplitude to the magnetic ring 110 wound by it, and under the drive of the high-frequency oscillation signal, the magnetic ring 110 may enter a non-magnetic saturation state from a magnetic saturation state.

[0075] In a specific implementation, the wake-up signal may further include a fourth wake-up signal, and the wake-up operation may include a fourth wake-up operation. After performing the third wake-up operation, the magnetic modulation circuit 120 may perform a fourth wake-up operation based on the fourth wake-up signal to generate a fourth magnetic modulation driving signal applied to the magnetic ring 110 .

[0076] In one embodiment, after the third wake-up operation is performed, the magnetic modulation state detection module 130 outputs a fourth wake-up signal to the magnetic modulation driving module 122; after receiving the fourth wake-up signal, the magnetic modulation driving module 122 applies a fourth magnetic modulation driving signal to the coil 121 wound on the magnetic ring 110. If the magnetic ring 110 has entered a non-magnetic saturation state from a magnetic saturation state, then under the drive of the fourth magnetic modulation driving signal, the magnetic ring 110 will return to the hysteresis loop and operate normally to generate an oscillating waveform on the coil 121. Then, the working state of the magnetic modulation circuit 120 can be detected. If it is normal, the magnetic ring 110 can be driven by the magnetic modulation driving signal generated by the magnetic modulation driving module 122 to form an oscillating waveform on the coil 121.

[0077] In another embodiment, after the third wake-up operation is performed, the magnetic modulation state detection module 130 outputs a fourth wake-up signal to the coil 121; after receiving the fourth wake-up signal, the coil 121 applies a fourth magnetic modulation drive signal to the magnetic ring 110 wound by it, and if the magnetic ring 110 has entered the non-magnetic saturation state from the magnetic saturation state, then under the drive of the fourth magnetic modulation drive signal, the magnetic ring 110 will return to the hysteresis loop and operate normally to generate an oscillating waveform on the coil 121. Then, the working state of the magnetic modulation circuit 120 can be detected, and if it is normal, the magnetic ring 110 can be driven by the magnetic modulation drive signal generated by the magnetic modulation drive module 122 to form an oscillating waveform on the coil 121.

[0078] Figure 4The current protection device 200 of the embodiment of the present invention is shown. Figure 1 , Figure 4 A trip module 150 and a switch 141 disposed on the conductor 140 are added.

[0079] In some embodiments, when the working state of the magnetic modulation circuit 120 is detected to be abnormal for the first time, the magnetic modulation state detection module 130 outputs a trip signal. The trip module 150 is connected to the magnetic modulation state detection module 130, and can receive the trip signal output by the magnetic modulation state detection module 130, and perform a disconnection operation on the conductor 140 based on the trip signal, such as applying a disconnection signal to the switch 141 to disconnect the circuit including the conductor 140.

[0080] In other embodiments, when the working state of the magnetic modulation circuit 120 is detected to be abnormal for the first time, the magnetic modulation state detection module 130 performs a recovery operation, and the recovery operation includes the magnetic modulation state detection module 130 outputting a wake-up signal (including the first, second, third and fourth wake-up signals) to the magnetic modulation circuit 120, the magnetic modulation circuit 120 performing a wake-up operation (including the first, second, third and fourth wake-up operations) and the magnetic modulation state detection module 130 detecting the working state of the magnetic modulation circuit 120; when the working state of the magnetic modulation circuit 120 is still abnormal after performing N recovery operations, the magnetic modulation state detection module 130 outputs a trip signal, where N is an integer greater than or equal to 1. The trip module 150 is connected to the magnetic modulation state detection module 130, and can receive the trip signal output by the magnetic modulation state detection module 130, and based on the trip signal, performs a disconnection operation on the conductor 140, for example, applying a disconnection signal to the switch 141 to disconnect the circuit including the conductor 140.

[0081] Figure 5 The current protection device 300 of the embodiment of the present invention is shown. Figure 4 , Figure 5 A demodulation module 160 and a current detection module 170 are added.

[0082] The demodulation module 160 is connected to the magnetic modulation driving module 122 , and can receive an oscillating waveform signal output by the magnetic modulation driving module 122 (eg, a signal sampled by a sampling resistor), and demodulate the signal to generate a demodulated signal.

[0083] The current detection module 170 is connected to the demodulation module 160, which can receive the demodulation signal output by the demodulation module 160 and detect the demodulation signal; when the effective value or peak value of the electrical parameter in the demodulation signal exceeds the set threshold, a trip signal is output, and the electrical parameter can be current, voltage or electric power.

[0084] The trip module 150 is connected to the current detection module 170 , and can receive a trip signal output by the current detection module 170 , and perform a disconnection operation on the conductor 140 based on the trip signal, such as applying a disconnection signal to the switch 141 to disconnect the circuit including the conductor 140 .

[0085] Figure 6 The current protection device 400 according to an embodiment of the present invention is illustrated, which includes a magnetic ring 210 , a first integrated circuit (IC1) 220 , a second integrated circuit (IC2) 230 , a first conductor 240 , a second conductor 245 , an analog-to-digital converter (ADC) 250 , and a solenoid 260 .

[0086] Similar to the magnetic ring 110 , the magnetic ring 210 is a closed-shaped magnetic conductor that allows at least one conductor through which a current to be measured can pass, and the current to be measured can be direct current or alternating current; wherein the conductors include a first conductor 240 and a second conductor 245 , wherein the conductor 240 is provided with a first switch 241 , and the conductor 245 is provided with a second switch 246 .

[0087] The magnetic modulation circuit includes coils 221 , 222 and IC1 , wherein the coils 221 , 222 are respectively wound on the magnetic ring 210 , and IC1 is respectively connected to the coils 221 , 222 .

[0088] Specifically, IC1 includes a driving circuit (not shown), a first driving pin MDRV1 and a first sensing pin MMN1 respectively connected to both ends of the coil 221 , and a second driving pin MDRV2 and a second sensing pin MMN2 respectively connected to both ends of the coil 222 .

[0089] The driving circuit is connected to the coil 221 via the first driving pin MDRV1 and the first sensing pin MMN1 to form a first magnetic modulation circuit, and the driving circuit is connected to the coil 222 via the second driving pin MDRV2 and the second sensing pin MMN2 to form a second magnetic modulation circuit. The first magnetic modulation circuit and the second magnetic modulation circuit form a magnetic modulation circuit of the current protection device 400.

[0090] The driving circuit outputs magnetic modulation driving signals to coils 221 and 222 through the first driving pin MDRV1 and the second driving pin MDRV2 respectively. After receiving the magnetic modulation driving signals, coils 221 and 222 generate magnetic field strength, which induces periodically changing magnetic field strength on the magnetic ring 210, thereby generating a basic oscillation waveform on the coils 221 and 222.

[0091] IC1 also includes a demodulation circuit (not shown), a first demodulation output pin DMO1, a second demodulation output pin DMO2, and a third sensing pin DMIN1 and a fourth sensing pin DMIN2 respectively connected to sampling resistors (composed of resistors R1, R2, and R3). The demodulation circuit collects the oscillation waveform of the magnetic modulation circuit through the third sensing pin DMIN1 and the fourth sensing pin DMIN2, and can filter out the high-frequency components in the oscillation waveform, thereby realizing demodulation; the first demodulation output pin DMO1 and the second demodulation output pin DMO2 are connected to the demodulation circuit to output the demodulation waveform.

[0092] The analog-to-digital conversion device 250 is connected to the first demodulation output pin DMO1 and the second demodulation output pin DMO2 to receive the demodulation waveform, and can convert the analog signal of the demodulation waveform into a digital signal.

[0093] IC2 may be a microprocessor unit (MCU), which is connected to the analog-to-digital conversion device 250 and can process the digital signal received from the analog-to-digital conversion device 250 in a programmed manner.

[0094] IC2 includes a magnetic modulation state detection circuit 231, which can be implemented in a programming manner.

[0095] The magnetic modulation state detection circuit 231 can detect the working state of the magnetic modulation circuit based on the input signal of its pin; it can also output a wake-up signal to the magnetic modulation circuit through the pin. The pin can be the first drive pin MDRV1 and the second drive pin MDRV2 (such as Figure 6 It may also be a first sensing pin MMN1 and a second sensing pin MMN2; it may also be a third sensing pin DMIN1 and a fourth sensing pin DMIN2.

[0096] When the magnetic modulation state detection circuit 231 detects that the working state of the magnetic modulation circuit is abnormal, it outputs a trip signal.

[0097] For example, when it is first detected that the working state of the magnetic modulation circuit is abnormal, the magnetic modulation state detection module 231 outputs a trip signal.

[0098] For another example, when it is first detected that the working state of the magnetic modulation circuit is abnormal, the magnetic modulation state detection module 231 performs a recovery operation, and the recovery operation includes the magnetic modulation state detection module 231 outputting a wake-up signal (including the first, second, third and fourth wake-up signals described above) to the magnetic modulation circuit, the magnetic modulation circuit performing a wake-up operation (including the first, second, third and fourth wake-up operations described above), and the magnetic modulation state detection module 231 detecting the working state of the magnetic modulation circuit; when the recovery operation is performed N times and the working state of the magnetic modulation circuit is still abnormal, the magnetic modulation state detection module 231 outputs a trip signal, where N is an integer greater than or equal to 1.

[0099] IC2 also includes an effective value judgment module 232, which can be implemented by programming. The effective value judgment module 232 receives a digital signal from the analog-to-digital conversion device 250, and outputs a trip signal when the effective value or peak value of an electrical parameter in the digital signal exceeds a set threshold. The electrical parameter can be current, voltage or electrical power.

[0100] IC2 can drive a thyristor module (SCR) and a solenoid 260, wherein the SCR is connected to IC2. Specifically, the first end of the SCR is connected to the effective value judgment module 232 and the magnetic modulation state detection module 231, respectively, the second end of the SCR is grounded, and the third end is connected to the first end of the solenoid 260; the second end of the solenoid 260 is connected to a power source, such as a conductor 245 (such as Figure 6 shown).

[0101] The solenoid 260 can receive a trip signal output by the magnetic modulation state detection module 231 or the effective value judgment module 232 through the SCR, and perform a disconnection operation on the conductors 240 and 245 based on the trip signal, such as applying a disconnection signal to the switches 241 and 246 respectively to disconnect the circuit including the conductors 240 and 245.

[0102] exist Figure 6 In the embodiment, resistor R4 and capacitor C1 form a filter for the first drive pin MDRV1, resistor R5 and capacitor C3 form a filter for the first sensing pin MMIN1, resistors R5, R8 and capacitor C6 form a differential filter, resistor R6 and capacitor C4 form a filter for the third sensing pin DMIN1, resistor R7 and capacitor C4 form a filter for the fourth sensing pin DMIN2, resistors R6, R7 and capacitor C4 form a differential filter, resistor R8 and capacitor C5 form a filter for the second sensing pin MMIN2, resistor R9 and capacitor C2 form a filter for the second drive pin MDRV2, resistors R10, R11 and capacitor C7 form a differential filter, resistor R12 is connected between one pin of the magnetic modulation state detection circuit 231 and the first drive pin MDRV1, resistor R13 is connected between another pin of the magnetic modulation state detection circuit 231 and the second drive pin MDRV2, and resistor R14 and capacitor C8 form a filter for the first end of the SCR.

[0103] Figure 7 The figure illustrates the waveforms of relevant parameters in the current protection device mentioned above when the oscillation stops due to an instantaneous large current. The current protection device has two driving pins respectively connected to two coils, and the two coils are respectively wound on a magnetic ring; it includes six sub-graphs, 6a, 6b, 6c, 6d, 6e and 6f, and the horizontal coordinates X of these six sub-graphs are all time and have a corresponding relationship.

[0104] In the child Figure 7 In a, it shows the instantaneous large current generated on the conductor, and its vertical coordinate Y1 is the current; wherein the instantaneous large current is, for example, an external electromagnetic interference signal, which generates an instantaneous current surge on the conductor.

[0105] In the child Figure 7 b shows the signal detected by the magnetic modulation state detection circuit and output by the magnetic modulation circuit, and its ordinate Y2 is the current. As shown in area 710, after the instantaneous large current is generated, the frequency of the oscillation waveform exceeds the preset frequency range (for example, the preset range of 300 Hz to 100 KHz) or the duty cycle exceeds the preset duty cycle range (for example, the preset range of 25% to 75%), and the current of the signal detected by the magnetic modulation state detection circuit increases instantaneously.

[0106] In the child Figure 7 c shows a signal output by a driving pin, and its ordinate Y3 is current or voltage; wherein the 1st, 2nd, 3rd, 6th, 7th, 8th and 9th levels are generated by the magnetic modulation circuit. After an instantaneous large current is generated on the conductor, the magnetic modulation state detection module outputs a first wake-up signal to the magnetic modulation circuit, and the magnetic modulation circuit generates a magnetic modulation drive signal applied to the magnetic ring based on the first wake-up signal, as shown in the 4th level; then the magnetic modulation state detection module outputs a second wake-up signal to the magnetic modulation circuit, and the magnetic modulation circuit generates a magnetic modulation drive signal applied to the magnetic ring based on the second wake-up signal, as shown in the 5th level.

[0107] In the child Figure 7 d shows the signal output by another drive pin, and its ordinate Y4 is current or voltage; wherein the 1st, 2nd, 3rd, 6th, 7th, 8th and 9th levels are generated by the magnetic modulation circuit. After an instantaneous large current is generated on the conductor, the magnetic modulation state detection module outputs a first wake-up signal to the magnetic modulation circuit, and the magnetic modulation circuit generates a magnetic modulation drive signal applied to the magnetic ring based on the first wake-up signal, as shown in the 4th level; then the magnetic modulation state detection module outputs a second wake-up signal to the magnetic modulation circuit, and the magnetic modulation circuit generates a magnetic modulation drive signal applied to the magnetic ring based on the second wake-up signal, as shown in the 5th level.

[0108] In the child Figure 7 e shows the differential signal of the two driving pins, and its vertical coordinate Y5 is the current or voltage; wherein the differential signal is based on the sub Figure 7 c, and is formed by the output signals of the two driving pins in 7d.

[0109] In the child Figure 7 In f, a trip signal is shown, and its vertical coordinate Y6 is current or voltage; wherein the trip signal is always at a low level, that is, no outputtable trip signal is generated.

[0110] Figure 8 The figure illustrates the waveforms of relevant parameters in the current protection device mentioned above when a continuous large current causes oscillation to stop. The current protection device has two driving pins respectively connected to two coils, and the two coils are respectively wound on a magnetic ring; it includes six sub-graphs 7a, 7b, 7c, 7d, 7e and 7f, and the horizontal coordinates X of these six sub-graphs are all time and have a corresponding relationship.

[0111] In the child Figure 8 In a, it shows the continuous large current generated on the conductor, and the vertical coordinate Z1 is the current.

[0112] In the child Figure 8 b shows the signal detected by the magnetic modulation state detection circuit and output by the magnetic modulation circuit, and its ordinate Z2 is the current. As shown in area 810, after the continuous large current is generated, the frequency of the oscillation waveform exceeds the preset frequency range (for example, the preset range of 300 Hz to 100 KHz) or the duty cycle exceeds the preset duty cycle range (for example, the preset range of 25% to 75%), and the signal detected by the magnetic modulation state detection circuit undergoes a continuous change.

[0113] In the child Figure 8 c shows a signal output by a driving pin, and its ordinate Z3 is current or voltage; wherein the 1st, 2nd and 3rd levels are generated by the magnetic modulation circuit. After a continuous large current is generated on the conductor, the magnetic modulation state detection module outputs a first wake-up signal to the magnetic modulation circuit, and the magnetic modulation circuit generates a magnetic modulation drive signal applied to the magnetic ring based on the first wake-up signal, as shown in the 4th level; then the magnetic modulation state detection module outputs a second wake-up signal to the magnetic modulation circuit, and the magnetic modulation circuit generates a magnetic modulation drive signal applied to the magnetic ring based on the second wake-up signal, as shown in the 5th level.

[0114] In the child Figure 8 d shows the signal output by another drive pin, and its ordinate Z4 is current or voltage; wherein the 1st, 2nd and 3rd levels are generated by the magnetic modulation circuit. After a continuous large current is generated on the conductor, the magnetic modulation state detection module outputs a first wake-up signal to the magnetic modulation circuit, and the magnetic modulation circuit generates a magnetic modulation drive signal applied to the magnetic ring based on the first wake-up signal, as shown in the 4th level; then the magnetic modulation state detection module outputs a second wake-up signal to the magnetic modulation circuit, and the magnetic modulation circuit generates a magnetic modulation drive signal applied to the magnetic ring based on the second wake-up signal, as shown in the 5th level.

[0115] In the child Figure 8 e shows the differential signal of the two drive pins, and its vertical coordinate Z5 is the current or voltage; wherein the differential signal is based on the sub Figure 8 c, and is formed by the output signals of the two driving pins in 8d.

[0116] In the child Figure 8 f shows a trip signal, and its ordinate Z6 is current or voltage; even if magnetic modulation drive signals applied to the magnetic ring are respectively generated based on the first wake-up signal and the second wake-up signal, the continuous large current still makes the magnetic ring in a magnetic saturation state and unable to exit, and the magnetic modulation state detection module then generates a trip signal, as shown in the second level, which is a high level, that is, a trip signal that can be output is generated.

[0117] Fig. 9 5 is a first flow chart of a current detection method according to an embodiment of the present invention. The method 500 comprises the following steps:

[0118] Step a, detecting the working state of the magnetic modulation circuit;

[0119] Step b, determining whether the working state is abnormal, and if so, outputting a wake-up signal;

[0120] Step c: performing a wake-up operation based on the wake-up signal.

[0121] During the execution of step a, the working state of the magnetic modulation circuit can be determined by detecting the frequency or duty cycle of the oscillation waveform generated by the magnetic modulation circuit.

[0122] During the execution of step b, it can be determined whether the working state is abnormal based on the detected oscillation waveform; for example, by determining whether the frequency of the detected oscillation waveform is less than 300Hz, the frequency is greater than 100KHz, the duty cycle is less than 25% or the duty cycle is greater than 75%, if so, the working state is determined to be abnormal.

[0123] During the execution of step c, the wake-up signal may include a first wake-up signal, the wake-up operation may include a first wake-up operation, and the magnetic modulation circuit performs the first wake-up operation based on the first wake-up signal to generate a first magnetic modulation drive signal applied to the magnetic ring, which is opposite to the direction of the second magnetic modulation drive signal that causes the magnetic ring to enter the most recent magnetic saturation state.

[0124] In the execution of step c, the wake-up signal may include a second wake-up signal, the wake-up operation may include a second wake-up operation, and the magnetic modulation circuit performs the second wake-up operation based on the second wake-up signal to generate a third magnetic modulation driving signal applied to the magnetic ring.

[0125] In the execution of step c, the wake-up signal may include a third wake-up signal, the wake-up operation may include a third wake-up operation, and the magnetic modulation circuit performs the third wake-up operation based on the third wake-up signal to generate a high-frequency oscillation signal with a gradually decreasing amplitude applied to the magnetic ring.

[0126] In the execution of step c, the wake-up signal may include a fourth wake-up signal, the wake-up operation may include a fourth wake-up operation, and the magnetic modulation circuit performs the fourth wake-up operation based on the fourth wake-up signal to apply a fourth magnetic modulation driving signal to the magnetic ring.

[0127] Fig.10 This is a second flow chart of the current detection method according to an embodiment of the present invention. Compared with method 500, method 600 adds a judgment of "whether the number of wake-up times exceeds N times", where N is an integer greater than or equal to 1.

[0128] Specifically, if the working state of the magnetic modulation circuit does not become normal (ie, abnormal), steps a, b and c are executed N times in a loop; then it is determined whether the number of loop executions exceeds N times, and if so, a trip signal is output.

[0129] In some embodiments, when it is first detected that the working state of the magnetic modulation circuit is abnormal, a recovery operation can be performed, and the recovery operation includes the magnetic modulation state detection module outputting a wake-up signal to the magnetic modulation circuit (including the first, second, third and fourth wake-up signals described above), the magnetic modulation circuit performing a wake-up operation (including the first, second, third and fourth wake-up operations described above), and the magnetic modulation state detection module detecting the working state of the magnetic modulation circuit 120; when the recovery operation is performed N times and the working state of the magnetic modulation circuit is still abnormal, the magnetic modulation state detection module outputs a trip signal.

[0130] A disconnection operation may be performed on the conductor based on the trip signal, such as applying a disconnection signal to a switch on the conductor to disconnect a circuit including the conductor.

[0131] The current detection method of the embodiment of the present invention is based on the above combination Figures 1 to 8 Therefore, the execution of each step in the current detection method and the relationship between each step can refer to the above description of the current protection device, which will not be repeated here.

[0132] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A current protection device, characterized in that: include: a magnetic ring adapted to allow at least one conductor through which a current to be measured can pass; A magnetic modulation circuit, comprising a coil and a magnetic modulation driving module and adapted to generate an oscillating waveform on the coil, wherein the coil is wound on the magnetic ring and the magnetic modulation driving module is connected to the coil; a magnetic modulation state detection module connected to the magnetic modulation circuit and adapted to determine the working state of the magnetic modulation circuit by detecting the oscillation waveform, wherein when the working state is abnormal, the magnetic modulation state detection module outputs a wake-up signal to the magnetic modulation circuit; The magnetic modulation state detection module is suitable for outputting a wake-up signal to the magnetic modulation circuit, and the wake-up signal is suitable for causing the magnetic modulation circuit to perform a wake-up operation; the wake-up signal includes a third wake-up signal, and the wake-up operation includes a third wake-up operation. The magnetic modulation circuit is suitable for performing the third wake-up operation based on the third wake-up signal to generate a high-frequency oscillation signal with a gradually decreasing amplitude applied to the magnetic ring.

2. The current protection device according to claim 1, characterized in that: The magnetic modulation state detection module is adapted to determine the working state of the magnetic modulation circuit by detecting the frequency or duty cycle of the oscillation waveform.

3. The current protection device according to claim 2, characterized in that: When the detected frequency of the oscillation waveform is less than 300 Hz, the frequency is greater than 100 KHz, the duty cycle is less than 25%, or the duty cycle is greater than 75%, it is determined that the working state is abnormal.

4. The current protection device according to claim 1, characterized in that: The wake-up signal includes a first wake-up signal, the wake-up operation includes a first wake-up operation, and the magnetic modulation circuit is suitable for performing the first wake-up operation based on the first wake-up signal to generate a first magnetic modulation drive signal applied to the magnetic ring, which is opposite to the direction of the second magnetic modulation drive signal that causes the magnetic ring to enter the most recent magnetic saturation state.

5. The current protection device according to claim 4, characterized in that: The time width of the first wake-up operation is greater than half of a period of the oscillation waveform.

6. The current protection device according to claim 4, characterized in that: The wake-up signal includes a second wake-up signal, the wake-up operation includes a second wake-up operation, and the magnetic modulation circuit is adapted to perform the second wake-up operation based on the second wake-up signal after performing the first wake-up operation to generate a third magnetic modulation driving signal applied to the magnetic ring.

7. The current protection device according to claim 1, characterized in that: The frequency of the high-frequency oscillation signal gradually increases from 2 KHz to 100 KHz, and the amplitude gradually decreases from the power supply voltage to zero.

8. The current protection device according to claim 1, characterized in that: The wake-up signal includes a fourth wake-up signal, the wake-up operation includes a fourth wake-up operation, and the magnetic modulation circuit is adapted to perform the fourth wake-up operation based on the fourth wake-up signal after performing the third wake-up operation to generate a fourth magnetic modulation driving signal applied to the magnetic ring.

9. The current protection device according to claim 1, characterized in that: Also included is a trip module, wherein: The magnetic modulation state detection module is adapted to output a trip signal when detecting that the working state is abnormal; The trip module is connected to the magnetic modulation state detection module and is adapted to perform a disconnection operation on the conductor based on the trip signal.

10. The current protection device according to any one of claims 4 to 8, characterized in that: Also included is a trip module, wherein: The magnetic modulation state detection module is adapted to output a trip signal when the working state is still abnormal after the magnetic modulation circuit performs the wake-up operation; The trip module is connected to the magnetic modulation state detection module and is adapted to perform a disconnection operation on the conductor based on the trip signal.

11. The current protection device according to any one of claims 1 to 8, characterized in that: Also includes: A demodulation module, connected to the magnetic modulation driving module and adapted to demodulate the oscillation waveform to generate a demodulation signal; A current detection module, connected to the demodulation module and adapted to detect the demodulation signal and output a trip signal when the effective value or peak value of an electrical parameter in the demodulation signal reaches a set threshold; A trip module is connected to the current detection module and is adapted to perform a disconnection operation on the conductor based on the trip signal.

12. A current detection method for the current protection device according to any one of claims 1 to 11, characterized in that: include: Step a, detecting the working state of the magnetic modulation circuit; Step b, determining whether the working state is abnormal, and if so, outputting a wake-up signal; the wake-up signal includes a third wake-up signal, the wake-up operation includes a third wake-up operation, and the magnetic modulation circuit performs the third wake-up operation based on the third wake-up signal to generate a high-frequency oscillation signal with a gradually decreasing amplitude applied to the magnetic ring; Step c: performing a wake-up operation based on the wake-up signal.

13. The current detection method according to claim 12, characterized in that: The wake-up signal includes a first wake-up signal, the wake-up operation includes a first wake-up operation, and the magnetic modulation circuit performs the first wake-up operation based on the first wake-up signal to generate a first magnetic modulation drive signal applied to the magnetic ring, which is opposite to the direction of the second magnetic modulation drive signal that causes the magnetic ring to enter the most recent magnetic saturation state.

14. The current detection method according to claim 13, characterized in that: The wake-up signal includes a second wake-up signal, the wake-up operation includes a second wake-up operation, and the magnetic modulation circuit performs the second wake-up operation based on the second wake-up signal after performing the first wake-up operation to generate a third magnetic modulation driving signal applied to the magnetic ring.

15. The current detection method according to claim 12, characterized in that: The wake-up signal includes a fourth wake-up signal, the wake-up operation includes a fourth wake-up operation, and the magnetic modulation circuit performs the fourth wake-up operation based on the fourth wake-up signal after performing the third wake-up operation to generate a fourth magnetic modulation driving signal applied to the magnetic ring.

16. The current detection method according to any one of claims 12 to 15, characterized in that: include: If the working state does not become normal, steps a, b and c are executed cyclically N times in total, where N is an integer greater than or equal to 1.

17. The current detection method according to claim 16, characterized in that: include: Determine whether the number of loop executions exceeds N times, and if so, output a trip signal; A disconnection operation is performed on the conductor based on the trip signal.

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