Self-recovery on-off device for preventing closing coil of circuit breaker from being burnt
By combining a PTC thermistor and a deformable metal sheet in the self-resetting switching module, the problem of easy burnout of the circuit breaker closing coil is solved, thus achieving stable operation and improved safety of the power system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-07
- Publication Date
- 2026-04-07
AI Technical Summary
The closing coil of a circuit breaker is prone to burnout due to overheating or excessive current, leading to instability and safety hazards in the power system.
The self-resetting switching module is adopted, which includes a PTC thermistor, a deformable metal sheet and a conductive plate. The thermistor heats up and causes the deformable metal sheet to bend and break the circuit, thus avoiding overheating of the closing coil. The self-resetting switching is achieved by combining the shape memory function of the nickel-titanium alloy sheet.
It effectively prevents the closing coil from burning out, improves the stability and safety of the power system, and reduces maintenance costs.
Smart Images
Figure CN224097406U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of power system protection, in particular to a kind of self-recovery on-off device for preventing breaker closing coil burnout. BACKGROUND
[0002] In power system, circuit breaker plays a vital role, it can be connected and disconnected in normal and fault conditions to circuit operation. The closing coil of circuit breaker is the key component to realize the closing operation of circuit breaker. In actual operation process, there are many factors that may cause the closing coil burnout. For example, when the closing instruction is issued, if the operating mechanism of circuit breaker cannot normally act due to mechanical failure, the closing coil will be burned due to overheat. In addition, if the control loop voltage is abnormally high or there is a short circuit fault, the current through the closing coil will be too large, which will cause the closing coil to burn out, which will not only cause damage to the circuit breaker, affect the normal operation of power system, and in severe cases, it will also cause fire and bring serious safety problems. SUMMARY
[0003] In view of the problems in the prior art, the utility model provides a kind of self-recovery on-off device for preventing breaker closing coil burnout, to solve the problem of burning circuit breaker closing coil in prior art, so as to improve the stability of power system, reduce maintenance cost and improve safety.
[0004] To achieve the above purpose, the technical scheme adopted by the utility model is: a kind of self-recovery on-off device for preventing breaker closing coil burnout, including first switch, self-recovery on-off module, second switch and closing coil connected in sequence, one end of the first switch is connected with positive bus, one end of the closing coil is connected with negative bus, the self-recovery on-off module includes PTC thermistor, deformation metal sheet and conductive plate, heat block is arranged between the PTC thermistor and the deformation metal sheet, one end of the PTC thermistor is electrically connected with one end of the deformation metal sheet, the other end of the deformation metal sheet is provided with hemispherical contact point, in normal working condition, the hemispherical contact point is in point contact with the conductive plate.
[0005] Based on the above, the implementation of the utility model is: when the current flows into the PTC thermistor through the external interface of the self-recovery on-off module, the PTC thermistor generates heat, and the heat is transmitted to the deformed metal sheet through the heat-conducting block after generating heat, one end of the deformed metal sheet is bent upwards after the deformed metal sheet reaches the design temperature, the hemisphere contact is disconnected with the conductive plate, the whole electric circuit is disconnected, the closing coil loses power, and when the heat of the deformed metal sheet is dissipated, the deformed metal sheet returns to the original state, the hemisphere contact is connected with the conductive plate, and the whole electric circuit is connected.
[0006] Further, the deformed metal sheet is a nickel-titanium alloy sheet.
[0007] Based on the above, the nickel-titanium alloy is a shape memory alloy, which can deform under heat and return to the original state after the temperature decreases, so that the utility model can realize the self-recovery on-off function.
[0008] Further, the heat-conducting block is a heat-conducting silica gel sheet.
[0009] Based on the above, the heat-conducting silica gel sheet is a high-soft, high-compliant and high-compression-ratio heat-conducting interface material, which has high heat-conducting effect, insulation and damping effect, and can improve the service life of the product.
[0010] In order to make the above features of the utility model and the purposes to be achieved more clearly, the utility model is further described in combination with the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS
[0011] Figure 1 It is a structure principle schematic view of the utility model;
[0012] Figure 2 It is a structure principle schematic view of the utility model under the condition of power failure in normal working condition;
[0013] Figure 3 It is a structure principle schematic view of the utility model under the condition of power failure in abnormal working condition.
[0014] Explanation of reference numerals: first switch S1; self-recovery on-off module 1; second switch K1; closing coil 2; negative bus KM-; PTC thermistor 3; deformed metal sheet 4; conductive plate 5; heat-conducting block 6; hemisphere contact 7. DETAILED DESCRIPTION
[0015] As Figure 1As shown in the figure, the self-recovery on-off device for preventing the closing coil of the circuit breaker from burning includes a first switch S1, a self-recovery on-off module 1, a second switch K1 and a closing coil 2 connected in sequence, one end of the first switch S1 is connected with a positive bus KM+, one end of the closing coil 2 is connected with a negative bus KM-, the self-recovery on-off module 1 includes a PTC thermistor 3, a deformation metal sheet 4 and a conductive plate 5, a heat-conducting block 6 is arranged between the PTC thermistor 3 and the deformation metal sheet 4, one end of the PTC thermistor 3 is electrically connected with one end of the deformation metal sheet 4, the other end of the deformation metal sheet 4 is provided with a hemispherical contact 7, under normal working conditions, the hemispherical contact 7 is in point contact with the conductive plate 5.
[0016] When the current flows into the PTC thermistor 3 through the external interface of the self-recovery on-off module 1, the PTC thermistor 3 generates heat, and the heat is transmitted to the deformation metal sheet 4 through the heat-conducting block 6, when the deformation metal sheet 4 reaches the design temperature after being heated, one end of the deformation metal sheet 4 bends upward, so that the hemispherical contact 7 is disconnected with the conductive plate 5, the whole electric circuit is disconnected, and the closing coil 2 loses power, when the heat of the deformation metal sheet 4 is dissipated, the deformation metal sheet 4 returns to the original state, the hemispherical contact 7 is connected with the conductive plate 5, and the whole electric circuit is connected. When the circuit breaker fails, the self-recovery on-off module 1 can avoid the overheat and burning of the closing coil 2, so that the operation of the circuit system is more stable, the maintenance cost is saved, and the safety is improved.
[0017] Preferably, the deformation metal sheet 4 is a nickel-titanium alloy sheet. The nickel-titanium alloy is a shape memory alloy, which can deform when heated and return to the original state after the temperature decreases, so that the self-recovery on-off function of the utility model can be realized.
[0018] Preferably, the heat-conducting block 6 is a heat-conducting silica gel sheet. The heat-conducting silica gel sheet is a kind of heat-conducting interface material with high softness, high compliance and high compression ratio, which has the effects of high heat conduction, insulation and shock absorption, and can improve the service life of the product.
[0019] The specific implementation of the embodiment is as follows: Figure 2 As shown in the figure, under normal working conditions, the first switch S1 is closed, the current passes through the self-recovery device to the closing coil 2, the closing coil 2 is powered and performs switching action, so that the second switch K1 is disconnected, at this time, the closing coil 2 and the self-recovery on-off module 1 lose power at the same time. Under normal working conditions, the current passes for a short time, the heat generated by the PTC thermistor 3 does not reach the set value of the deformation metal sheet 4, and the deformation metal sheet 4 does not deform.
[0020] AsFigure 3 As shown in the abnormal condition, the first switch S1 is closed, the current passes through the self-recovery device to the closing coil 2, the closing coil 2 is powered, the second switch K1 is not disconnected under the action of the closing coil 2, the closing coil 2 and the self-recovery on-off module 1 remain powered, the PTC thermistor 3 continues to heat, when the temperature reaches the deformation threshold of the deformed metal sheet 4, one end of the deformed metal sheet 4 bends upward, the hemispherical contact 7 is disconnected with the conductive plate 5, thereby achieving the effect of protecting the closing coil 2.
[0021] The above is only the most optimal solution embodiment of the present application, and is not used to limit the present application. Various modifications or replacements of the present application made by those skilled in the art without departing from the essence and protection scope of the present application should be within the protection scope of the present application.
Claims
1. A self-resetting switching device for preventing the closing coil of a circuit breaker from burning out, characterized in that: The application relates to a self-recovery on-off module, which comprises a first switch (S1), a self-recovery on-off module (1), a second switch (K1) and a closing coil (2) connected in sequence, one end of the first switch (S1) is connected with a positive bus (KM+), one end of the closing coil (2) is connected with a negative bus (KM-), the self-recovery on-off module (1) comprises a PTC thermistor (3), a deformed metal sheet (4) and a conductive plate (5), a heat-conducting block (6) is arranged between the PTC thermistor (3) and the deformed metal sheet (4), one end of the PTC thermistor (3) is electrically connected with one end of the deformed metal sheet (4), the other end of the deformed metal sheet (4) is provided with a hemispherical contact (7), and the hemispherical contact (7) is in point contact with the conductive plate (5) under normal working conditions.
2. A self-restoring on-off device for preventing the burnout of a closing coil of a circuit breaker according to claim 1, characterized in that: The deformed metal sheet (4) is a nickel-titanium alloy sheet.
3. A self-restoring on-off device for preventing the burnout of a closing coil of a circuit breaker according to claim 1, characterized in that: The heat-conducting block (6) is a heat-conducting silica gel sheet.