Current transformer open circuit protection method and system applying magnetic latching relay

Abstract

The invention provides a current transformer open circuit protection method and system applying a magnetic latching relay. The two groups of magnetic latching relays are respectively connected in parallel and in series in a secondary winding loop, when the circuit works normally, the parallel magnetic latching relays are kept in a normally open state, and the series magnetic latching relays are kept in a closed state; the voltage of the secondary winding is monitored in real time through the voltage monitoring module, the voltage is compared with a set voltage threshold value through the voltage comparator circuit, and a comparison level signal is output; through a current transformer secondary overvoltage protector, current transformer secondary loop voltage limiting protection is carried out; according to a high-level signal output by the comparator, a magnetic latching relay is driven to trigger action, and when the abnormal open-circuit voltage of the secondary winding loop of the current transformer suddenly changes, the load of the secondary winding loop is disconnected; and audible and visual alarm and action contact information output are carried out.

Description

Technical Field

[0001] The present invention relates to the field of magnetic flux holding signal control safety protection technology, and more specifically, to a current transformer open circuit protection method and system using a magnetic holding relay. Background Art

[0002] An open circuit in the secondary winding of a current transformer may cause abnormally high voltage, damaging the current transformer and other equipment. The abnormal sudden change in high voltage may also cause personal injury. How to set up a more effective open circuit protection scheme is crucial. A magnetic latching relay is a relay that can maintain its working state unchanged after power is on or off. How to set the secondary winding loop path and the magnetic latching relay state of the magnetic latching relay, how to more accurately detect the secondary winding voltage and output a control signal, how to more perfectly protect the secondary circuit of the current transformer, how to accurately control the triggering action of the drive magnetic latching relay, disconnect the secondary winding loop load and alarm when the abnormal open circuit voltage of the secondary winding loop of the current transformer suddenly changes, and other issues remain to be solved. Therefore, it is necessary to propose a current transformer open circuit protection method and system using a magnetic latching relay to at least partially solve the problems existing in the prior art. Summary of the invention

[0003] A series of simplified concepts are introduced in the content of the invention, which will be further described in detail in the specific implementation method section; the content of the invention of the present invention does not mean to attempt to limit the key features and essential technical features of the technical solution claimed for protection, nor does it mean to attempt to determine the scope of protection of the technical solution claimed for protection.

[0004] In order to at least partially solve the above problems, the present invention provides a current transformer open circuit protection method using a magnetic latching relay, comprising:

[0005] S100, two sets of magnetic latching relays are respectively connected in parallel and in series in the secondary winding circuit. When the circuit is working normally, the parallel magnetic latching relay remains in a normally open state, and the series magnetic latching relay remains in a closed state;

[0006] S200, monitor the secondary winding voltage in real time through the voltage monitoring module, compare it with the set voltage threshold through the voltage comparator circuit, and output a comparison level signal;

[0007] S300, performs voltage limiting protection on the secondary circuit of the current transformer through the secondary overvoltage protector of the current transformer;

[0008] S400, according to the high level signal output by the comparator, drives the magnetic latching relay to trigger the action, and disconnects the secondary winding circuit load when the abnormal open circuit voltage of the secondary winding circuit of the current transformer suddenly changes; and outputs sound and light alarms and action contact information.

[0009] Preferably, S100 includes:

[0010] S101, respectively connect two groups of magnetic latching relays in parallel and in series in the secondary winding loop; the two groups of magnetic latching relays and the secondary winding loop form a parallel magnetic latching relay structure and a series magnetic latching relay structure; the parallel magnetic latching relay is connected in parallel with both ends of the secondary winding; the input end of the series magnetic latching relay is connected to the output end of the secondary winding, and the output end of the magnetic latching relay is connected to the load;

[0011] S102, when the circuit is working normally, the parallel magnetic latching relay remains in a normally open state, the series magnetic latching relay remains in a closed state, and the circuit conduction does not affect the secondary winding loop;

[0012] Magnetic latching relays include: monostable magnetic latching relays or bistable magnetic latching relays.

[0013] Preferably, S200 includes:

[0014] S201, monitoring the secondary winding voltage in real time through a voltage monitoring module to obtain a secondary winding voltage monitoring signal;

[0015] S202, setting a voltage threshold according to the secondary winding loop load;

[0016] S203, inputting the secondary winding voltage monitoring signal into the voltage comparator circuit, comparing it with the set voltage threshold, and obtaining a voltage comparison result; outputting a comparison level signal according to the voltage comparison result;

[0017] The voltage monitoring module includes: a voltage sensor or a resistor divider; the comparison level signal includes: a high level signal and a low level signal.

[0018] Preferably, S300 includes:

[0019] S301, connecting two terminals of the secondary overvoltage protector of the current transformer in parallel with two ends of the secondary winding of the current transformer;

[0020] S302, when the secondary circuit of the current transformer works normally, the secondary overvoltage protector of the current transformer is in a high-resistance state. When the secondary circuit of the current transformer generates overvoltage, the secondary overvoltage protector of the current transformer acts quickly to perform voltage limiting protection on the secondary circuit of the current transformer.

[0021] Preferably, S400 includes:

[0022] S401, according to the high-level signal output by the comparator, when the abnormal open-circuit voltage of the secondary winding loop of the current transformer suddenly changes, the magnetic latching overvoltage protection control module is used to drive the magnetic latching relay to trigger the action and disconnect the secondary winding loop load;

[0023] S402, performing an audible and visual alarm and an action contact output corresponding to an abnormal open circuit of the secondary winding circuit of the current transformer;

[0024] S403, after the fault is eliminated, when it is detected that the secondary winding voltage returns to normal, the magnetic latching relay is controlled to reset, and the secondary overvoltage protector of the current transformer is controlled to short-circuit reset, so as to restore the normal operation of the secondary winding.

[0025] The present invention provides a current transformer open circuit protection system using a magnetic latching relay, comprising:

[0026] The magnetic latching relay protection subsystem connects two sets of magnetic latching relays in parallel and in series in the secondary winding circuit. When the circuit is working normally, the parallel magnetic latching relay remains in the normally open state, and the series magnetic latching relay remains in the closed state.

[0027] The winding monitoring signal comparison subsystem monitors the secondary winding voltage in real time through the voltage monitoring module, compares it with the set voltage threshold through the voltage comparator circuit, and outputs a comparison level signal;

[0028] The secondary circuit voltage limiting protection subsystem performs voltage limiting protection on the secondary circuit of the current transformer through the secondary overvoltage protector of the current transformer;

[0029] The sudden change control alarm output subsystem drives the magnetic latching relay to trigger the action according to the high-level signal output by the comparator. When the abnormal open-circuit voltage of the secondary winding circuit of the current transformer suddenly changes, the secondary winding circuit load is disconnected; and an audible and visual alarm and action contact information are output.

[0030] Preferably, the magnetic latching relay protection subsystem comprises:

[0031] The magnetic latching connection subsystem connects two groups of magnetic latching relays in parallel and in series in the secondary winding loop respectively; the two groups of magnetic latching relays form a parallel magnetic latching relay structure and a series magnetic latching relay structure with the secondary winding loop respectively; the parallel magnetic latching relay is connected in parallel with both ends of the secondary winding; the input end of the series magnetic latching relay is connected with the output end of the secondary winding, and the output end of the magnetic latching relay is connected with the load;

[0032] Steady-state magnetic latching subsystem: When the circuit is working normally, the parallel magnetic latching relay remains in the normally open state, the series magnetic latching relay remains in the closed state, and the circuit conduction does not affect the secondary winding loop;

[0033] Magnetic latching relays include: monostable magnetic latching relays or bistable magnetic latching relays.

[0034] Preferably, the winding monitoring signal comparison subsystem includes:

[0035] The winding voltage monitoring subsystem monitors the secondary winding voltage in real time through the voltage monitoring module and obtains the secondary winding voltage monitoring signal;

[0036] The protection voltage threshold setting subsystem sets the voltage threshold according to the secondary winding loop load;

[0037] The voltage comparison signal transmission subsystem inputs the secondary winding voltage monitoring signal into the voltage comparator circuit, compares it with the set voltage threshold, obtains the voltage comparison result; and outputs the comparison level signal according to the voltage comparison result;

[0038] The voltage monitoring module includes: a voltage sensor or a resistor divider; the comparison level signal includes: a high level signal and a low level signal.

[0039] Preferably, the secondary circuit voltage limiting protection subsystem comprises:

[0040] A secondary overvoltage connection subsystem connects two terminals of the secondary overvoltage protector of the current transformer in parallel with two ends of the secondary winding of the current transformer;

[0041] High-resistance normal overvoltage protection subsystem: when the current transformer secondary circuit works normally, the current transformer secondary overvoltage protector is in a high-resistance state. When the current transformer secondary circuit generates overvoltage, the current transformer secondary overvoltage protector acts quickly to perform voltage limiting protection on the current transformer secondary circuit.

[0042] Preferably, the mutation control warning output subsystem includes:

[0043] The sudden change trigger control driving subsystem outputs a high-level signal according to the comparator. When the abnormal open-circuit voltage of the secondary winding loop of the current transformer suddenly changes, the magnetic latching relay is driven to trigger the action through the magnetic latching overvoltage protection control module to disconnect the secondary winding loop load;

[0044] The sound and light alarm and action contact output subsystem performs sound and light alarm and action contact output corresponding to abnormal open circuit of secondary winding circuit of current transformer;

[0045] The relay overvoltage reset subsystem, after the fault is eliminated, when it is detected that the secondary winding voltage has returned to normal, controls the magnetic latching relay to reset, and controls the short-circuit reset of the secondary overvoltage protector of the current transformer to restore the normal operation of the secondary winding.

[0046] Compared with the prior art, the present invention has at least the following beneficial effects:

[0047] The present invention discloses a current transformer open circuit protection method and system using a magnetic latching relay. Two groups of magnetic latching relays are respectively connected in parallel and in series in a secondary winding loop. When the circuit is working normally, the parallel magnetic latching relays are kept in a normally open state, and the series magnetic latching relays are kept in a closed state. The secondary winding voltage is monitored in real time by a voltage monitoring module, and compared with a set voltage threshold by a voltage comparator circuit to output a comparison level signal. The current transformer secondary circuit is voltage-limited by a current transformer secondary overvoltage protector. According to the high-level signal output by the comparator, the magnetic latching relay is driven to trigger an action, and when the secondary winding loop of the current transformer is abnormally open, the magnetic latching relay is triggered to activate the current transformer secondary winding circuit. When the voltage suddenly changes, the secondary winding loop load is disconnected; and an audible and visual alarm and action contact information output are performed; Quick response: Quick response at the moment of secondary winding open circuit to avoid high voltage damage to the current transformer; High reliability: The stability and reliability of the magnetic latching relay under various working conditions are significantly improved; Easy maintenance: Easy to install and maintain, and easy to restore normal working state after troubleshooting; It can effectively improve the protection effect of the current transformer when the secondary winding is open circuit; Rapidly switch states when the secondary winding is open circuit, provide reliable open circuit protection, and avoid high voltage damage to the current transformer; After the fault is eliminated, the normal operation of the secondary winding is restored by resetting the relay.

[0048] The present invention describes a current transformer open circuit protection method and system using a magnetic latching relay. Other advantages, objectives and features of the present invention will be partially reflected through the following description, and will also be partially understood by technicians in this field through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0050] Figure 1 This is a diagram of an embodiment of a current transformer open circuit protection method using a magnetic latching relay as described in the present invention.

[0051] Figure 2 This is another embodiment of a current transformer open circuit protection method and system using a magnetic latching relay as described in the present invention.

[0052] Figure 3 This is a diagram of an embodiment of a current transformer open circuit protection system using a magnetic latching relay as described in the present invention. DETAILED DESCRIPTION

[0053] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the instructions. As shown in the drawings, the present invention provides a current transformer open circuit protection method using a magnetic latching relay, comprising:

[0054] S100, two sets of magnetic latching relays are respectively connected in parallel and in series in the secondary winding circuit. When the circuit is working normally, the parallel magnetic latching relay remains in a normally open state, and the series magnetic latching relay remains in a closed state;

[0055] S200, monitor the secondary winding voltage in real time through the voltage monitoring module, compare it with the set voltage threshold through the voltage comparator circuit, and output a comparison level signal;

[0056] S300, performs voltage limiting protection on the secondary circuit of the current transformer through the secondary overvoltage protector of the current transformer;

[0057] S400, according to the high level signal output by the comparator, drives the magnetic latching relay to trigger the action, and disconnects the secondary winding circuit load when the abnormal open circuit voltage of the secondary winding circuit of the current transformer suddenly changes; and outputs sound and light alarms and action contact information.

[0058] The principle and effect of the above technical solution are as follows: the present invention provides a current transformer open circuit protection method using a magnetic latching relay, comprising: connecting two groups of magnetic latching relays in parallel and in series in the secondary winding circuit respectively, when the circuit is working normally, the parallel magnetic latching relays remain in a normally open state, and the series magnetic latching relays remain in a closed state; the secondary winding voltage is monitored in real time by a voltage monitoring module, and compared with a set voltage threshold by a voltage comparator circuit, and a comparison level signal is output; the secondary circuit of the current transformer is voltage-limited by a current transformer secondary overvoltage protector; according to the high-level signal output by the comparator, the magnetic latching relay is driven to trigger the action, and the secondary winding voltage of the current transformer is output. When the winding circuit opens abnormally and the voltage suddenly changes, the secondary winding circuit load is disconnected; and an audible and visual alarm and action contact information output are performed; Quick response: Quick response at the moment of secondary winding open circuit to avoid high voltage damage to the current transformer; High reliability: The stability and reliability of the magnetic latching relay are significantly improved under various working conditions; Easy maintenance: Easy to install and maintain, and easy to restore normal working state after troubleshooting; It can effectively improve the protection effect of the current transformer when the secondary winding is open circuit; Rapidly switch states when the secondary winding is open circuit, provide reliable open circuit protection, and avoid high voltage damage to the current transformer; After troubleshooting, the normal operation of the secondary winding is restored by resetting the relay.

[0059] In one embodiment, S100 includes:

[0060] S101, respectively connect two groups of magnetic latching relays in parallel and in series in the secondary winding loop; the two groups of magnetic latching relays and the secondary winding loop form a parallel magnetic latching relay structure and a series magnetic latching relay structure; the parallel magnetic latching relay is connected in parallel with both ends of the secondary winding; the input end of the series magnetic latching relay is connected to the output end of the secondary winding, and the output end of the magnetic latching relay is connected to the load;

[0061] S102, when the circuit is working normally, the parallel magnetic latching relay remains in a normally open state, the series magnetic latching relay remains in a closed state, and the circuit conduction does not affect the secondary winding loop;

[0062] Magnetic latching relays include: monostable magnetic latching relays or bistable magnetic latching relays.

[0063] The principle and effect of the above technical solution are as follows: two groups of magnetic latching relays are respectively connected in parallel and in series in the secondary winding circuit; the two groups of magnetic latching relays are respectively connected with the secondary winding circuit to form a parallel magnetic latching relay structure and a series magnetic latching relay structure; the parallel magnetic latching relay is connected in parallel with both ends of the secondary winding; the input end of the series magnetic latching relay is connected to the output end of the secondary winding, and the output end of the magnetic latching relay is connected to the load; when the circuit is working normally, the parallel magnetic latching relay remains in a normally open state, the series magnetic latching relay remains in a closed state, and the circuit conduction does not affect the secondary winding circuit; the magnetic latching relay includes: a monostable magnetic latching relay or a bistable magnetic latching relay; the magnetic latching relay includes: a pressure-changing contact structure and The movable contact curved surface structure; the pressure-transformer contact structure is arranged as a plurality of combined curved pressure-transformer contact pieces; the plurality of combined curved pressure-transformer contact pieces are a plurality of C-shaped piezoelectric pieces, the outer convex surface of the C-shaped piezoelectric piece is a C-shaped outer convex conductor, the inner concave surface is a C-shaped inner concave piezoelectric ceramic body, the C-shaped outer convex conductor is an elastic conductor piece which is attached to the C-shaped inner concave piezoelectric ceramic body and deforms along with the C-shaped inner concave piezoelectric ceramic body; one end of the C-shaped outer convex conductor contacts the conductive static piece; when the circuit is open, the voltage generates the deformation of the C-shaped inner concave piezoelectric ceramic body, and the other end of the C-shaped outer convex conductor is attached to the movable contact curved surface structure to form a more stable attached structure; when the circuit is open, the C-shaped inner concave piezoelectric ceramic body recovers from the loss of pressure, so that the other end of the C-shaped outer convex conductor is disconnected from the movable contact curved surface structure more quickly.

[0064] In one embodiment, S200 includes:

[0065] S201, monitoring the secondary winding voltage in real time through a voltage monitoring module to obtain a secondary winding voltage monitoring signal;

[0066] S202, setting a voltage threshold according to the secondary winding loop load;

[0067] S203, inputting the secondary winding voltage monitoring signal into the voltage comparator circuit, comparing it with the set voltage threshold, and obtaining a voltage comparison result; outputting a comparison level signal according to the voltage comparison result;

[0068] The voltage monitoring module includes: a voltage sensor or a resistor divider; the comparison level signal includes: a high level signal and a low level signal.

[0069] The principle and effect of the above technical solution are: the secondary winding voltage is monitored in real time by the voltage monitoring module to obtain the secondary winding voltage monitoring signal; the voltage threshold is set according to the secondary winding loop load; the secondary winding voltage monitoring signal is input into the voltage comparator circuit, compared with the set voltage threshold, and the voltage comparison result is obtained; according to the voltage comparison result, a comparison level signal is output; the voltage monitoring module includes: a voltage sensor or a resistor divider; the comparison level signal includes: a high level signal and a low level signal; the secondary winding voltage monitoring signal is input into the voltage comparator circuit, compared with the set voltage threshold, and the voltage comparison result is obtained; according to the voltage comparison result, a comparison level signal is output, including: the secondary winding voltage monitoring signal is input into the voltage comparator circuit, and compared with the set voltage threshold; when the secondary winding voltage does not exceed the set voltage threshold, it is determined that the secondary winding is not open, and the voltage comparator circuit outputs a low level signal; when the secondary winding voltage exceeds the set voltage threshold, it is determined that the secondary winding is open, and the voltage comparator circuit outputs a high level signal.

[0070] In one embodiment, S300 includes:

[0071] S301, connecting two terminals of the secondary overvoltage protector of the current transformer in parallel with two ends of the secondary winding of the current transformer;

[0072] S302, when the secondary circuit of the current transformer works normally, the secondary overvoltage protector of the current transformer is in a high-resistance state. When the secondary circuit of the current transformer generates overvoltage, the secondary overvoltage protector of the current transformer acts quickly to perform voltage limiting protection on the secondary circuit of the current transformer.

[0073] The principle and effect of the above technical solution are as follows: the two terminals of the current transformer secondary overvoltage protector are connected in parallel with the two ends of the current transformer secondary winding; when the current transformer secondary circuit works normally, the current transformer secondary overvoltage protector is in a high-resistance state, and when the current transformer secondary circuit generates an overvoltage, the current transformer secondary overvoltage protector quickly acts to perform voltage-limiting protection for the current transformer secondary circuit; when the current transformer secondary circuit works normally, the current transformer secondary overvoltage protector is in a high-resistance state, and when the current transformer secondary circuit generates an overvoltage, the current transformer secondary overvoltage protector quickly acts to perform voltage-limiting protection for the current transformer secondary circuit Including: when the circuit is working normally, the secondary overvoltage protector of the current transformer is in a high-resistance state, and the leakage current is extremely small, which does not affect the normal operation of the secondary circuit of the current transformer; when an overvoltage is generated in the secondary circuit of the current transformer, the secondary overvoltage protector of the current transformer quickly operates and switches to a low-resistance state, limiting the voltage of the secondary circuit of the current transformer within the normal voltage range, and performing secondary circuit voltage limiting protection; after the secondary circuit voltage limiting protection is triggered, the short-circuit delay protects the secondary circuit load, and sends out an overvoltage warning signal, intelligently prompts the fault location, and transmits the overvoltage warning signal and fault location information through wireless communication to the magnetic holding overvoltage protection control module.

[0074] In one embodiment, S400 includes:

[0075] S401, according to the high-level signal output by the comparator, when the abnormal open-circuit voltage of the secondary winding loop of the current transformer suddenly changes, the magnetic latching overvoltage protection control module is used to drive the magnetic latching relay to trigger the action and disconnect the secondary winding loop load;

[0076] S402, performing an audible and visual alarm and an action contact output corresponding to an abnormal open circuit of the secondary winding circuit of the current transformer;

[0077] S403, after the fault is eliminated, when it is detected that the secondary winding voltage returns to normal, the magnetic latching relay is controlled to reset, and the secondary overvoltage protector of the current transformer is controlled to short-circuit reset, so as to restore the normal operation of the secondary winding.

[0078] The principle and effect of the above technical solution are as follows: according to the high-level signal output by the comparator, when the voltage of the secondary winding circuit of the current transformer is abnormally open-circuited and suddenly changes, the magnetic latching relay is driven to trigger the action through the magnetic latching overvoltage protection control module to disconnect the secondary winding circuit load; the sound and light alarm and action contact output corresponding to the abnormal open circuit of the secondary winding circuit of the current transformer are performed; after the fault is eliminated, when it is detected that the secondary winding voltage returns to normal, the magnetic latching relay is controlled to reset, and the secondary overvoltage protector of the current transformer is controlled to reset short circuit, and the normal operation of the secondary winding is restored; when it is detected that the secondary winding voltage returns to normal, the magnetic latching relay is controlled to reset short circuit, and the secondary overvoltage protector of the current transformer is controlled to reset short circuit, and the normal operation of the secondary winding is restored; when it is detected that the secondary winding voltage returns to normal after the fault is eliminated ... winding of the current transformer is restored to normal operation; when it is detected that the secondary winding voltage returns to normal after the fault is eliminated, the magnetic latching relay is controlled to reset short circuit, and the secondary winding of the current transformer is restored to normal operation after the fault is eliminated. When the secondary winding voltage returns to normal, the magnetic latching relay is controlled to reset, and the secondary overvoltage protector of the current transformer is controlled to be short-circuited and reset, including: in the control circuit of the magnetic latching relay, the magnetic latching relay is reset through a reset button or an automatic reset circuit; through the reset button or the automatic reset circuit, when it is detected that the secondary winding voltage returns to normal, the reset button is turned on or the automatic reset circuit automatically triggers the relay to reset; and the secondary overvoltage protector of the current transformer is controlled to be short-circuited and reset; in order to avoid false triggering, a delay mechanism is set to automatically reset after the secondary winding voltage is stable.

[0079] The present invention provides a current transformer open circuit protection system using a magnetic latching relay, comprising:

[0080] The magnetic latching relay protection subsystem connects two sets of magnetic latching relays in parallel and in series in the secondary winding circuit. When the circuit is working normally, the parallel magnetic latching relay remains in the normally open state, and the series magnetic latching relay remains in the closed state.

[0081] The winding monitoring signal comparison subsystem monitors the secondary winding voltage in real time through the voltage monitoring module, compares it with the set voltage threshold through the voltage comparator circuit, and outputs a comparison level signal;

[0082] The secondary circuit voltage limiting protection subsystem performs voltage limiting protection on the secondary circuit of the current transformer through the secondary overvoltage protector of the current transformer;

[0083] The sudden change control alarm output subsystem drives the magnetic latching relay to trigger the action according to the high-level signal output by the comparator. When the abnormal open-circuit voltage of the secondary winding circuit of the current transformer suddenly changes, the secondary winding circuit load is disconnected; and an audible and visual alarm and action contact information are output.

[0084] The principle and effect of the above technical solution are as follows: the present invention provides a current transformer open circuit protection system using a magnetic latching relay, comprising: a magnetic latching relay protection subsystem, which connects two groups of magnetic latching relays in parallel and in series in the secondary winding circuit respectively. When the circuit is working normally, the parallel magnetic latching relay remains in a normally open state, and the series magnetic latching relay remains in a closed state; a winding monitoring signal comparison subsystem, which monitors the secondary winding voltage in real time through a voltage monitoring module, compares it with the set voltage threshold through a voltage comparator circuit, and outputs a comparison level signal; a secondary circuit voltage limiting protection subsystem, which performs voltage limiting protection on the secondary circuit of the current transformer through a secondary overvoltage protector of the current transformer; a mutation control alarm output subsystem, which outputs a high level according to the comparator The signal drives the magnetic latching relay to trigger the action. When the secondary winding circuit of the current transformer has an abnormal open-circuit voltage mutation, the secondary winding circuit load is disconnected; and an audible and visual alarm and action contact information output are performed; fast response: rapid response at the moment of secondary winding open circuit to avoid high voltage damage to the current transformer; high reliability: the stability and reliability of the magnetic latching relay under various working conditions are significantly improved; convenient maintenance: easy to install and maintain, and easy to restore normal working state after troubleshooting; can effectively improve the protection effect of the current transformer when the secondary winding is open circuit; quickly switch states when the secondary winding is open circuit, provide reliable open circuit protection, and avoid high voltage damage to the current transformer; after troubleshooting, the normal operation of the secondary winding is restored by resetting the relay.

[0085] In one embodiment, the magnetic latching relay protection subsystem includes:

[0086] The magnetic latching connection subsystem connects two groups of magnetic latching relays in parallel and in series in the secondary winding loop respectively; the two groups of magnetic latching relays form a parallel magnetic latching relay structure and a series magnetic latching relay structure with the secondary winding loop respectively; the parallel magnetic latching relay is connected in parallel with both ends of the secondary winding; the input end of the series magnetic latching relay is connected with the output end of the secondary winding, and the output end of the magnetic latching relay is connected with the load;

[0087] Steady-state magnetic latching subsystem: When the circuit is working normally, the parallel magnetic latching relay remains in the normally open state, the series magnetic latching relay remains in the closed state, and the circuit conduction does not affect the secondary winding loop;

[0088] Magnetic latching relays include: monostable magnetic latching relays or bistable magnetic latching relays.

[0089] The principle and effect of the above technical solution are as follows: the magnetic latching relay protection subsystem includes: a magnetic latching connection subsystem, which connects two groups of magnetic latching relays in parallel and in series in the secondary winding circuit respectively; the two groups of magnetic latching relays form a parallel magnetic latching relay structure and a series magnetic latching relay structure with the secondary winding circuit respectively; the parallel magnetic latching relay is connected in parallel with both ends of the secondary winding; the input end of the series magnetic latching relay is connected with the output end of the secondary winding, and the output end of the magnetic latching relay is connected with the load; the steady-state magnetic latching subsystem, when the circuit is working normally, the parallel magnetic latching relay remains in a normally open state, the series magnetic latching relay remains in a closed state, and the circuit conduction does not affect the secondary winding circuit; the magnetic latching relay includes: a monostable magnetic latching relay or a bistable magnetic latching relay; The magnetic holding relay includes: a pressure-changing contact structure and a moving contact curved surface structure; the pressure-changing contact structure is arranged as a plurality of combined curved surface pressure-changing contact pieces; the plurality of combined curved surface pressure-changing contact pieces are a plurality of C-shaped piezoelectric pieces, the outer convex surface of the C-shaped piezoelectric piece is a C-shaped outer convex conductor, the inner concave surface is a C-shaped inner concave piezoelectric ceramic body, the C-shaped outer convex conductor is an elastic conductor piece which is attached to the C-shaped inner concave piezoelectric ceramic body and deforms along with the C-shaped inner concave piezoelectric ceramic body; one end of the C-shaped outer convex conductor contacts a conductive static piece; when the circuit is open, the voltage generates the deformation of the C-shaped inner concave piezoelectric ceramic body, and the other end of the C-shaped outer convex conductor is attached to the moving contact curved surface structure to form a more stable attached structure; when the circuit is open, the C-shaped inner concave piezoelectric ceramic body recovers from the loss of pressure, so that the other end of the C-shaped outer convex conductor is disconnected from the moving contact curved surface structure more quickly.

[0090] In one embodiment, the winding monitoring signal comparison subsystem includes:

[0091] The winding voltage monitoring subsystem monitors the secondary winding voltage in real time through the voltage monitoring module and obtains the secondary winding voltage monitoring signal;

[0092] The protection voltage threshold setting subsystem sets the voltage threshold according to the secondary winding loop load;

[0093] The voltage comparison signal transmission subsystem inputs the secondary winding voltage monitoring signal into the voltage comparator circuit, compares it with the set voltage threshold, obtains the voltage comparison result; and outputs the comparison level signal according to the voltage comparison result;

[0094] The voltage monitoring module includes: a voltage sensor or a resistor divider; the comparison level signal includes: a high level signal and a low level signal.

[0095] The principle and effect of the above technical solution are as follows: the winding monitoring signal comparison subsystem includes: the winding voltage monitoring subsystem, which monitors the secondary winding voltage in real time through the voltage monitoring module and obtains the secondary winding voltage monitoring signal; the protection voltage threshold setting subsystem, which sets the voltage threshold according to the secondary winding loop load; the voltage comparison signal transmission subsystem, which inputs the secondary winding voltage monitoring signal into the voltage comparator circuit, compares it with the set voltage threshold, and obtains the voltage comparison result; outputs the comparison level signal according to the voltage comparison result; the voltage monitoring module includes: a voltage sensor or a resistor divider; the comparison level signal package The method comprises: inputting the secondary winding voltage monitoring signal into the voltage comparator circuit, comparing it with the set voltage threshold, and obtaining the voltage comparison result; outputting the comparison level signal according to the voltage comparison result, including: inputting the secondary winding voltage monitoring signal into the voltage comparator circuit, comparing it with the set voltage threshold; when the secondary winding voltage does not exceed the set voltage threshold, it is determined that the secondary winding is not open-circuited, and the voltage comparator circuit outputs a low-level signal; when the secondary winding voltage exceeds the set voltage threshold, it is determined that the secondary winding is open-circuited, and the voltage comparator circuit outputs a high-level signal.

[0096] In one embodiment, the secondary circuit voltage limiting protection subsystem includes:

[0097] A secondary overvoltage connection subsystem connects two terminals of the secondary overvoltage protector of the current transformer in parallel with two ends of the secondary winding of the current transformer;

[0098] High-resistance normal overvoltage protection subsystem: when the current transformer secondary circuit works normally, the current transformer secondary overvoltage protector is in a high-resistance state. When the current transformer secondary circuit generates overvoltage, the current transformer secondary overvoltage protector acts quickly to perform voltage limiting protection on the current transformer secondary circuit.

[0099] The principle and effect of the above technical solution are as follows: the secondary circuit voltage limiting protection subsystem includes: a secondary overvoltage connection subsystem, which connects the two terminals of the secondary overvoltage protector of the current transformer in parallel with the two ends of the secondary winding of the current transformer; a high-resistance normal overvoltage protection subsystem, when the secondary circuit of the current transformer works normally, the secondary overvoltage protector of the current transformer is in a high-resistance state, and when the secondary circuit of the current transformer generates an overvoltage, the secondary overvoltage protector of the current transformer acts quickly to perform voltage limiting protection for the secondary circuit of the current transformer; when the secondary circuit of the current transformer works normally, the secondary overvoltage protector of the current transformer is in a high-resistance state, and when the secondary circuit of the current transformer generates an overvoltage, the secondary overvoltage protector of the current transformer acts quickly to perform voltage limiting protection for the secondary circuit of the current transformer The system quickly acts to perform voltage limiting protection on the secondary circuit of the current transformer, including: when the circuit is working normally, the secondary overvoltage protector of the current transformer is in a high-resistance state, and the leakage current is extremely small, which does not affect the normal operation of the secondary circuit of the current transformer; when an overvoltage is generated in the secondary circuit of the current transformer, the secondary overvoltage protector of the current transformer quickly acts and converts to a low-resistance state, limiting the voltage of the secondary circuit of the current transformer within the normal voltage range, and performing voltage limiting protection on the secondary circuit; after the voltage limiting protection on the secondary circuit is triggered, the short-circuit delay protects the secondary circuit load, and sends out an overvoltage warning signal, intelligently prompts the fault location, and transmits the overvoltage warning signal and fault location information through wireless communication to the magnetic holding overvoltage protection control module.

[0100] In one embodiment, the mutation control warning output subsystem includes:

[0101] The sudden change trigger control driving subsystem outputs a high-level signal according to the comparator. When the abnormal open-circuit voltage of the secondary winding loop of the current transformer suddenly changes, the magnetic latching relay is driven to trigger the action through the magnetic latching overvoltage protection control module to disconnect the secondary winding loop load;

[0102] The sound and light alarm and action contact output subsystem performs sound and light alarm and action contact output corresponding to abnormal open circuit of secondary winding circuit of current transformer;

[0103] The relay overvoltage reset subsystem, after the fault is eliminated, when it is detected that the secondary winding voltage has returned to normal, controls the magnetic latching relay to reset, and controls the short-circuit reset of the secondary overvoltage protector of the current transformer to restore the normal operation of the secondary winding.

[0104] The principle and effect of the above technical solution are as follows: the sudden change control alarm output subsystem includes: the sudden change trigger control drive subsystem, which outputs a high-level signal according to the comparator. When the voltage of the secondary winding circuit of the current transformer is abnormally open and suddenly changes, the magnetic latching relay is driven to trigger the action through the magnetic latching overvoltage protection control module to disconnect the secondary winding circuit load; the sound and light alarm and action contact output subsystem performs the sound and light alarm and action contact output corresponding to the abnormal open circuit of the secondary winding circuit of the current transformer; the relay overvoltage reset subsystem controls the magnetic latching relay to reset and controls the secondary winding circuit of the current transformer after the fault is eliminated when it is detected that the secondary winding voltage returns to normal. The secondary overvoltage protector is short-circuited and reset to restore the normal operation of the secondary winding; when it is detected that the secondary winding voltage has returned to normal, the magnetic latching relay is controlled to reset, and the short-circuit reset of the secondary overvoltage protector of the current transformer is controlled. The reset includes: in the control circuit of the magnetic latching relay, the magnetic latching relay is reset by a reset button or an automatic reset circuit; when it is detected that the secondary winding voltage has returned to normal, the reset button is turned on or the automatic reset circuit automatically triggers the relay to reset by the reset button or the automatic reset circuit; and the short-circuit reset of the secondary overvoltage protector of the current transformer is controlled; in order to avoid false triggering, a delay mechanism is set to automatically reset after the secondary winding voltage is stable.

[0105] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A current transformer open circuit protection method using a magnetic latching relay, characterized in that: include: S100, two sets of magnetic latching relays are respectively connected in parallel and in series in the secondary winding circuit. When the circuit is working normally, the parallel magnetic latching relay remains in a normally open state, and the series magnetic latching relay remains in a closed state; S200, monitor the secondary winding voltage in real time through the voltage monitoring module, compare it with the set voltage threshold through the voltage comparator circuit, and output a comparison level signal; S300, performs voltage limiting protection on the secondary circuit of the current transformer through the secondary overvoltage protector of the current transformer; S400, according to the high level signal output by the comparator, drives the magnetic latching relay to trigger the action, and disconnects the secondary winding circuit load when the abnormal open circuit voltage of the secondary winding circuit of the current transformer suddenly changes; and outputs sound and light alarms and action contact information.

2. A current transformer open circuit protection method using a magnetic latching relay according to claim 1, characterized in that: S100 includes: S101, respectively connect two groups of magnetic latching relays in parallel and in series in the secondary winding loop; the two groups of magnetic latching relays and the secondary winding loop form a parallel magnetic latching relay structure and a series magnetic latching relay structure; the parallel magnetic latching relay is connected in parallel with both ends of the secondary winding; the input end of the series magnetic latching relay is connected to the output end of the secondary winding, and the output end of the magnetic latching relay is connected to the load; S102, when the circuit is working normally, the parallel magnetic latching relay remains in a normally open state, the series magnetic latching relay remains in a closed state, and the circuit conduction does not affect the secondary winding loop; Magnetic latching relays include: monostable magnetic latching relays or bistable magnetic latching relays.

3. A current transformer open circuit protection method using a magnetic latching relay according to claim 1, characterized in that: S200 includes: S201, monitoring the secondary winding voltage in real time through a voltage monitoring module to obtain a secondary winding voltage monitoring signal; S202, setting a voltage threshold according to the secondary winding loop load; S203, inputting the secondary winding voltage monitoring signal into the voltage comparator circuit, comparing it with the set voltage threshold, and obtaining a voltage comparison result; outputting a comparison level signal according to the voltage comparison result; The voltage monitoring module includes: a voltage sensor or a resistor divider; the comparison level signal includes: a high level signal and a low level signal.

4. A current transformer open circuit protection method using a magnetic latching relay according to claim 1, characterized in that: S300 includes: S301, connecting two terminals of the secondary overvoltage protector of the current transformer in parallel with two ends of the secondary winding of the current transformer; S302, when the secondary circuit of the current transformer works normally, the secondary overvoltage protector of the current transformer is in a high-resistance state. When the secondary circuit of the current transformer generates overvoltage, the secondary overvoltage protector of the current transformer acts quickly to perform voltage limiting protection on the secondary circuit of the current transformer.

5. The current transformer open circuit protection method using a magnetic latching relay according to claim 1, characterized in that: S400 includes: S401, according to the high-level signal output by the comparator, when the abnormal open-circuit voltage of the secondary winding loop of the current transformer suddenly changes, the magnetic latching overvoltage protection control module is used to drive the magnetic latching relay to trigger the action and disconnect the secondary winding loop load; S402, performing an audible and visual alarm and an action contact output corresponding to an abnormal open circuit of the secondary winding circuit of the current transformer; S403, after the fault is eliminated, when it is detected that the secondary winding voltage returns to normal, the magnetic latching relay is controlled to reset, and the secondary overvoltage protector of the current transformer is controlled to short-circuit reset, so as to restore the normal operation of the secondary winding.

6. A current transformer open circuit protection system using a magnetic latching relay, characterized in that: include: The magnetic latching relay protection subsystem connects two sets of magnetic latching relays in parallel and in series in the secondary winding circuit. When the circuit is working normally, the parallel magnetic latching relay remains in the normally open state, and the series magnetic latching relay remains in the closed state. The winding monitoring signal comparison subsystem monitors the secondary winding voltage in real time through the voltage monitoring module, compares it with the set voltage threshold through the voltage comparator circuit, and outputs a comparison level signal; The secondary circuit voltage limiting protection subsystem performs voltage limiting protection on the secondary circuit of the current transformer through the secondary overvoltage protector of the current transformer; The sudden change control alarm output subsystem drives the magnetic latching relay to trigger the action according to the high-level signal output by the comparator. When the abnormal open-circuit voltage of the secondary winding circuit of the current transformer suddenly changes, the secondary winding circuit load is disconnected; and an audible and visual alarm and action contact information are output.

7. A current transformer open circuit protection system using a magnetic latching relay according to claim 6, characterized in that: Magnetic latching relay protection subsystem, including: The magnetic latching connection subsystem connects two groups of magnetic latching relays in parallel and in series in the secondary winding loop respectively; the two groups of magnetic latching relays form a parallel magnetic latching relay structure and a series magnetic latching relay structure with the secondary winding loop respectively; the parallel magnetic latching relay is connected in parallel with both ends of the secondary winding; the input end of the series magnetic latching relay is connected with the output end of the secondary winding, and the output end of the magnetic latching relay is connected with the load; Steady-state magnetic latching subsystem: When the circuit is working normally, the parallel magnetic latching relay remains in the normally open state, the series magnetic latching relay remains in the closed state, and the circuit conduction does not affect the secondary winding loop; Magnetic latching relays include: monostable magnetic latching relays or bistable magnetic latching relays.

8. A current transformer open circuit protection system using a magnetic latching relay according to claim 6, characterized in that: Winding monitoring signal comparison subsystem, including: The winding voltage monitoring subsystem monitors the secondary winding voltage in real time through the voltage monitoring module and obtains the secondary winding voltage monitoring signal; The protection voltage threshold setting subsystem sets the voltage threshold according to the secondary winding loop load; The voltage comparison signal transmission subsystem inputs the secondary winding voltage monitoring signal into the voltage comparator circuit, compares it with the set voltage threshold, obtains the voltage comparison result; and outputs the comparison level signal according to the voltage comparison result; The voltage monitoring module includes: a voltage sensor or a resistor divider; the comparison level signal includes: a high level signal and a low level signal.

9. A current transformer open circuit protection system using a magnetic latching relay according to claim 6, characterized in that: The secondary circuit voltage limiting protection subsystem includes: A secondary overvoltage connection subsystem connects two terminals of the secondary overvoltage protector of the current transformer in parallel with two ends of the secondary winding of the current transformer; High-resistance normal overvoltage protection subsystem: when the current transformer secondary circuit works normally, the current transformer secondary overvoltage protector is in a high-resistance state. When the current transformer secondary circuit generates overvoltage, the current transformer secondary overvoltage protector acts quickly to perform voltage limiting protection on the current transformer secondary circuit.

10. A current transformer open circuit protection system using a magnetic latching relay according to claim 6, characterized in that: The mutation control alarm output subsystem includes: The sudden change trigger control driving subsystem outputs a high-level signal according to the comparator. When the abnormal open-circuit voltage of the secondary winding loop of the current transformer suddenly changes, the magnetic latching relay is driven to trigger the action through the magnetic latching overvoltage protection control module to disconnect the secondary winding loop load; The sound and light alarm and action contact output subsystem performs sound and light alarm and action contact output corresponding to abnormal open circuit of secondary winding circuit of current transformer; The relay overvoltage reset subsystem, after the fault is eliminated, when it is detected that the secondary winding voltage has returned to normal, controls the magnetic latching relay to reset, and controls the short-circuit reset of the secondary overvoltage protector of the current transformer to restore the normal operation of the secondary winding.

Images