A multi-pulse surge protector
By introducing a multi-pulse surge protection circuit and a double ferrite shielding layer into the surge protector, the heat problem caused by the single shielding layer is solved, achieving efficient electromagnetic energy absorption and reducing heat generation, thus improving the performance of the surge protector.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGDONG YUEDIAN ZHUHAI OFFSHORE WIND POWER CO LTD
- Filing Date
- 2025-06-12
- Publication Date
- 2026-05-26
AI Technical Summary
Existing surge pulsers use only a single shielding layer, which causes most of the electromagnetic energy to generate eddy current losses and hysteresis losses in the shielding layer, generating a lot of heat and requiring external heat dissipation equipment to assist in heat dissipation.
A multi-pulse surge protector is adopted, which includes a multi-pulse surge protection circuit, a ferrite shielding layer, and a ferrite reinforcement layer. The multi-pulse surge protection circuit consists of three branches, each of which consists of a fuse, a thermally protected varistor, a feedthrough capacitor, and a first Litz coil. The ferrite shielding layer is laid on the outer surface, and the ferrite reinforcement layer is laid on the inner wall. The double ferrite shielding layer enhances the absorption efficiency of electromagnetic field of lightning current leakage.
It effectively reduces the heat generation of the shielding layer, improves the absorption efficiency of electromagnetic energy, avoids eddy current loss and hysteresis loss caused by a single shielding layer, and reduces the dependence on heat dissipation equipment.
Smart Images
Figure CN224289302U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of surge protector technology, and in particular to a multi-pulse surge protector. Background Technology
[0002] The internal charge polarity of a thundercloud is positive at the top and negative at the bottom, with an electric field strength reaching 50-100 mV. Typically, a discharge phenomenon occurs within the thundercloud, known as a pre-breakdown process, providing conditions for the formation of a tiered (downward) leader. When the electric field strength at the bottom reaches the air ionization threshold, a downward-moving streamer begins to form, breaking down the air an average distance of about 50 meters each time. This sequence resembles a tiered structure, hence the name tiered leader, also known as a downward leader. Influenced by the electric field at the end of the downward leader, the lightning rod tip induces charges of opposite polarity to those at the end of the downward leader. When the electric field strength reaches 10 kV / m, corona discharge occurs, generating an upward-directed corona current (streamer), known as an upward leader. The relative motion between the upward and downward leaders provides the necessary conditions for their connection.
[0003] Lightning discharge multi-pulse waveforms, such as Figure 1 As shown, when the upward leader develops to approximately 100m from the tip of the lightning rod, it connects with the downward leader. The distance between the ends of the upward and downward leaders (the last jump) is called the strike distance, denoted by r. Typically, the value of r is related to the lightning discharge current. After the upper and lower leaders connect, a discharge channel is formed. Charge rushes from the ground along the discharge channel to the cloud to neutralize the channel and the thundercloud charge; this process is called the first return stroke. The arrow leader moves along the lightning channel after the first lightning strike. It is named for its arrow-like shape, as its path extends from the top to the bottom of the channel. It serves as a transition between the first and subsequent return strokes, acting as a link between them. The subsequent return stroke begins after the arrow leader ends, continuously repeating the discharge process of the first return stroke. Because each return stroke is a pulse, multiple return strokes form a timed pulse train. After the lightning channel is established by the first return stroke, a charge exists in the channel to maintain it until the discharge ends. Between subsequent return strokes, a pulsating current with a constant direction of motion can be observed at the bottom of the pulse; this is called the continuous current. The continuous current is defined as the lower amplitude current immediately following the return stroke and is the pulsating DC component of the lightning current in the lightning channel. Above the continuous current, several small pulses can be seen; this is called the M-component, and it is one of the three forms of charge transfer from lightning to the ground. The continuous current transfers a large amount of charge (approximately 50%), resulting in the most severe lightning damage, including thermal effects. The final return stroke refers to the last return stroke, characterized by a time interval of 300-400 ms between the previous and final return strokes. Its amplitude is greater than that of the first return stroke, and its parameters are similar to those of the first return stroke. From the first return stroke to the final lightning strike, one lightning discharge process ends.
[0004] Current surge pulsers use only a single shielding layer, which causes most of the electromagnetic energy to generate eddy current losses and hysteresis losses in the shielding layer, generating a lot of heat so that external heat dissipation equipment is required to assist in heat dissipation. Utility Model Content
[0005] This invention provides a multi-pulse surge protector to solve the technical problem that existing surge pulsers use only a single shielding layer, which causes most of the electromagnetic energy to generate eddy current loss and hysteresis loss in the shielding layer, resulting in a large amount of heat and requiring external heat dissipation equipment to assist in heat dissipation.
[0006] In view of this, the present invention provides a multi-pulse surge protector, including a multi-pulse surge protection circuit, a ferrite shielding layer, and a ferrite reinforcement layer;
[0007] The multi-pulse surge protection circuit includes three branches connected in parallel. Each branch consists of a fuse, a thermally protected varistor, a feedthrough capacitor, and a first Litz coil. One end of the fuse is connected to the live wire, and the other end of the fuse is connected to one end of the feedthrough capacitor. The other end of the feedthrough capacitor is connected to one end of the thermally protected varistor, and the other end of the thermally protected varistor is grounded. The first Litz coil is connected in parallel with the feedthrough capacitor. The starting voltage of the thermally protected varistor on the three branches is set in a stepped manner.
[0008] A ferrite shielding layer is laid on the outer surface of the multi-pulse surge protector housing;
[0009] The ferrite reinforcement layer is laid on the inner wall of the multi-pulse surge protector housing, and the housing of the multi-pulse surge protector is grounded.
[0010] Optionally, the feedthrough capacitor has a capacitance of 4700pF.
[0011] Optionally, the inductance of the first Litz coil is 54mH.
[0012] Optionally, the first Litz coil is wound with 0.1 mm Litz wire.
[0013] Optionally, the first Litz coil is made of three layers of 0.1mm Litz wire wound with ferrite magnetic winding, with 100 turns in each layer.
[0014] Optionally, the starting voltage of the thermally protected varistors on the three branches is set in a ratio of 1:1.03:1.0609.
[0015] Optionally, a second Litz coil is also included;
[0016] The second Litz coil is laid on the ferrite reinforcement layer by direct grounding.
[0017] Optionally, the inductance of the second Litz coil is 22mH.
[0018] Optionally, the second Litz coil is wound with 0.1 mm Litz wire.
[0019] Optionally, the second Litz coil is made of 4 layers of 0.1mm Litz wire, with 85 turns in each layer, and the coil diameter of the second Litz coil is 50mm.
[0020] As can be seen from the above technical solutions, the multi-pulse surge protector provided by this utility model has the following advantages:
[0021] The multi-pulse surge protector provided by this utility model includes a multi-pulse surge protection circuit, a ferrite shielding layer, and a ferrite reinforcement layer. The multi-pulse surge protection circuit includes three branches connected in parallel. Each branch consists of a fuse, a thermally protected varistor, a feedthrough capacitor, and a first Litz coil. One end of the fuse is connected to the live wire, and the other end of the fuse is connected to one end of the feedthrough capacitor. The other end of the feedthrough capacitor is connected to one end of the thermally protected varistor, and the other end of the thermally protected varistor is grounded. The first Litz coil is connected in parallel with the feedthrough capacitor. The starting voltage of the thermally protected varistor on the three branches is set in a stepped manner. The ferrite shielding layer is laid on the outer surface of the multi-pulse surge protector housing, and the ferrite reinforcement layer is laid on the inner wall of the multi-pulse surge protector housing. By employing a dual ferrite shielding system consisting of a ferrite reinforcement layer and a ferrite shielding layer, the absorption efficiency of electromagnetic fields from lightning current leakage can be enhanced. The ferrite shielding layer is directly grounded through the casing of the multi-pulse surge protector, forming a shielding effect on the inside of the surge protector and absorbing the remaining leakage electromagnetic field. This minimizes the heating of the shielding layer and solves the technical problem that existing surge pulsers, which only use a single shielding layer, cause most of the electromagnetic energy to generate eddy current losses and hysteresis losses in the shielding layer, resulting in a large amount of heat and requiring external heat dissipation equipment. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is a multi-pulse waveform diagram of lightning discharge;
[0024] Figure 2 This is a schematic diagram of the structure of a multi-pulse surge protector provided in an embodiment of this utility model;
[0025] Figure 3This is a schematic diagram of the circuit structure of the multi-pulse surge protection circuit provided in the embodiment of this utility model. Detailed Implementation
[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0027] For easier understanding, please refer to Figure 2 and Figure 3 This utility model provides an embodiment of a multi-pulse surge protector, including a multi-pulse surge protection circuit, a ferrite shielding layer 100, and a ferrite reinforcement layer 300. The multi-pulse surge protection circuit includes three branches connected in parallel. Each branch consists of a fuse F, a thermally protected varistor R, a feedthrough capacitor C, and a first Litz coil L. One end of the fuse F is connected to the live wire, and the other end of the fuse F is connected to one end of the feedthrough capacitor C. The other end of the feedthrough capacitor C is connected to one end of the thermally protected varistor R, and the other end of the thermally protected varistor R is grounded. The first Litz coil L is connected in parallel with the feedthrough capacitor C. The starting voltage of the thermally protected varistor R on the three branches is set in a stepped manner. The ferrite shielding layer 100 is laid on the outer surface of the multi-pulse surge protector housing, and the ferrite reinforcement layer 300 is laid on the inner wall of the multi-pulse surge protector housing. The multi-pulse surge protector housing is grounded.
[0028] It should be noted that the fuse F and the thermally protected varistor R form a power frequency short-circuit protection circuit. The fuse F is a backup protection device capable of breaking when a large pulse current passes through it, assuming a power frequency short-circuit current. The thermally protected varistor R also has a built-in fusible alloy. This dual protection of fuse F and thermally protected varistor R in series ensures that if the thermally protected varistor R cannot withstand excessive energy, it will be disconnected from the main circuit, protecting the entire circuit and preventing low-voltage distribution lines from being affected by short circuits. This serves as a backup protection device and allows for direct breaking without the need to replace the thermally protected varistor R with a copper block during power frequency short-circuit tests. The three branches of the three thermally protected varistor R connected in parallel form a high-voltage electromagnetic pulse energy gradient absorption circuit. Arranging the varistors in the three branches in a specific voltage gradient order allows the varistors within the surge protector to conduct step by step, effectively dissipating lightning current energy. The starting voltages of the thermally protected varistors R on the three branches are set in a ratio of 1:1.03:1.0609. The feedthrough capacitors C on the three branches have a capacitance of 4700pF. The first Litz coil L is made of three layers of 0.1mm Litz wire wound ferrite magnetic coils, with 100 turns in each layer, and an inductance of 54mH. The feedthrough capacitors C and the first Litz coil L form a passive resonant circuit, which can directionally absorb 10kHz lightning electromagnetic waves and reduce the leakage of lightning electromagnetic fields. At the same time, due to the use of passive components, the heat generated in the shielding layer by the lightning electromagnetic field due to eddy current effects and hysteresis losses can be reduced.
[0029] Feedthrough capacitors (C) are primarily used for high-frequency electromagnetic noise suppression, covering a range of 10MHz-10GHz. They employ a three-terminal structure, offering several advantages: First, they eliminate lead inductance. Traditional capacitor leads introduce parasitic inductance (approximately 1-10nH), leading to increased impedance at high frequencies. Feedthrough capacitors, however, are directly grounded through their metal casing, eliminating lead inductance. Second, they can operate at GHz levels (e.g., 1-10GHz) with even lower high-frequency impedance. Third, the capacitance value (typically 100pF-1μF) and the metal casing form a low-impedance path, bypassing high-frequency noise to ground. Finally, their internal multi-layer ceramic or thin-film structure optimizes the equivalent series inductance at high frequencies, ensuring wideband filtering performance.
[0030] A ferrite reinforcement layer 300 is laid on the inner wall of the multi-pulse surge protector housing 400, and a ferrite shielding layer 100 is laid on the outer surface of the multi-pulse surge protector housing 400. The housing 400 is reliably grounded. The ferrite shielding layer 100 has a hollow cuboid structure with a length of 71mm, a width of 45mm, a height of 50mm, and a thickness of 3mm. Through the double ferrite shielding of the ferrite reinforcement layer 300 and the ferrite shielding layer 100, the absorption efficiency of the electromagnetic field of lightning current leakage can be enhanced. The ferrite shielding layer 100 is directly grounded, forming a shielding effect on the inside of the surge protector, absorbing the remaining leakage electromagnetic field, and minimizing the heat generation of the shielding layer. This avoids the drawback of using only a single shielding layer, which would cause most of the electromagnetic energy to generate eddy current losses and hysteresis losses in the shielding layer, generating a large amount of heat and requiring external heat dissipation equipment.
[0031] The multi-pulse surge protection circuit includes three branches connected in parallel. Each branch consists of a fuse F, a thermally protected varistor R, a feedthrough capacitor C, and a first Litz coil L. One end of the fuse F is connected to the live wire, and the other end of the fuse F is connected to one end of the feedthrough capacitor C. The other end of the feedthrough capacitor C is connected to one end of the thermally protected varistor R, and the other end of the thermally protected varistor R is grounded. The first Litz coil L is connected in parallel with the feedthrough capacitor C. The starting voltage of the thermally protected varistor R on the three branches is set in a stepped manner. By connecting a pulse fuse F with a large pulse current carrying capacity and a small power frequency breaking capacity in parallel with a varistor, the current is evenly distributed to each branch, avoiding single-point overload and achieving graded absorption when lightning current passes through, effectively reducing the residual voltage generated by lightning current. At the same time, the fuse F equipped in each stage can ensure that if a certain thermal protection varistor R fails due to overload, it can accurately disconnect a certain branch, and the remaining branches can continue to work, ensuring that the overall protection is uninterrupted. This solves the technical problem that the existing surge pulsers, which use a switch or a hybrid design of switch and voltage limiting device, cannot meet the requirements for suppressing multi-pulse lightning discharge pulses due to insufficient energy and time coordination.
[0032] The multi-pulse surge protector provided by this utility model enhances the absorption efficiency of electromagnetic fields from lightning current leakage through double ferrite shielding with a ferrite reinforcement layer and a ferrite shielding layer. The ferrite shielding layer is directly grounded through the outer shell of the multi-pulse surge protector, forming a shielding effect on the inside of the surge protector and absorbing the remaining leakage electromagnetic field. This minimizes the heating of the shielding layer and solves the technical problem that existing surge pulsers use only a single shielding layer, which leads to the majority of electromagnetic energy generating eddy current losses and hysteresis losses in the shielding layer, resulting in a large amount of heat and requiring external heat dissipation equipment.
[0033] In one embodiment, the multi-pulse surge protector further includes a second Litz coil 200, which is directly grounded onto the ferrite reinforcement layer 300. The second Litz coil 200 and the ferrite reinforcement layer 300 absorb spatial electromagnetic fields and low-frequency electromagnetic pulse energy, dissipating it to the ground. The second Litz coil 200 is made of 4 layers of 0.1mm Litz wire, with 85 turns in each layer. The coil diameter of the second Litz coil 200 is 50mm, and its inductance is 22mH. The ferrite reinforcement layer 300 is laid on the inner wall of the surge protector housing 400. The ferrite reinforcement layer 300 has a hollow cuboid structure with a length of 50mm, a width of 38mm, a height of 40mm, and a thickness of 2mm.
[0034] The terms "first" and "second" in this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0035] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.
[0036] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A multi-pulse surge protector, characterized by, Includes a multi-pulse surge protection circuit, a ferrite shielding layer, and a ferrite reinforcement layer; The multi-pulse surge protection circuit includes three branches connected in parallel. Each branch consists of a fuse, a thermally protected varistor, a feedthrough capacitor, and a first Litz coil. One end of the fuse is connected to the live wire, and the other end of the fuse is connected to one end of the feedthrough capacitor. The other end of the feedthrough capacitor is connected to one end of the thermally protected varistor, and the other end of the thermally protected varistor is grounded. The first Litz coil is connected in parallel with the feedthrough capacitor. The starting voltage of the thermally protected varistor on the three branches is set in a stepped manner. A ferrite shielding layer is laid on the outer surface of the multi-pulse surge protector housing; The ferrite reinforcement layer is laid on the inner wall of the multi-pulse surge protector housing, and the housing of the multi-pulse surge protector is grounded.
2. The multi-pulse surge protector of claim 1, wherein, The capacitance of the feedthrough capacitor is 4700pF.
3. The multi-pulse surge protector of claim 2, wherein, The inductance of the first Litz coil is 54mH.
4. The multi-pulse surge protector of claim 3, wherein, The first Litz coil is wound with 0.1mm Litz wire.
5. The multi-pulse surge protector of claim 4, wherein, The first Litz coil is made of three layers of 0.1mm Litz wire wound with ferrite magnetic winding, with 100 turns in each layer.
6. The multi-pulse surge protector according to claim 1, characterized in that, The starting voltage of the thermal protection varistors on the three branches is set in a ratio of 1:1.03:1.0609.
7. The multi-pulse surge protector according to claim 1, characterized in that, It also includes a second Litz coil; The second Litz coil is laid on the ferrite reinforcement layer by direct grounding.
8. The multi-pulse surge protector according to claim 7, characterized in that, The inductance of the second Litz coil is 22mH.
9. The multi-pulse surge protector according to claim 8, characterized in that, The second Litz coil is made of 0.1mm Litz wire.
10. The multi-pulse surge protector according to claim 9, characterized in that, The second Litz coil is made of 4 layers of 0.1mm Litz wire, with 85 turns in each layer. The diameter of the second Litz coil is 50mm.