Overvoltage suppression system

Abstract

The invention relates to an overvoltage suppression system. The system comprises a controller, an ice melting device, a voltage measuring element, a ground wire, a first discharge assembly and a second discharge assembly, the controller is connected with the ice melting device; the voltage measuring element is connected with the controller and the ground wire. The output end of the ice melting device is connected with one end of the ground wire, and the other end of the ground wire is grounded; the first discharge assembly and the second discharge assembly are both connected with a ground wire; the first discharging assembly is used for discharging lightning stroke overvoltage of the ground wire to the ground, the second discharging assembly is used for discharging wire overvoltage of the ground wire to the ground, and the controller is used for starting the ice melting device to melt ice on the ground wire based on the fact that the voltage of the ground wire is within a set voltage range measured by the voltage measuring element. Thus, the lightning stroke overvoltage and the wire overvoltage are discharged to the ground respectively, the overvoltage on the ground wire is suppressed, the voltage of the ground wire is in the set voltage range, the ice melting device is further started, and normal and stable operation of the ice melting device is achieved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of power transmission lines, and in particular to an overvoltage suppression system. Background Art

[0002] With the development of my country's electric power industry, ultra-high voltage AC transmission lines have become the backbone of the entire power grid, and their transmission reliability has become a focus of attention in the power grid field.

[0003] UHV AC transmission lines mainly include ground wires and conductors for transmitting electric energy. Due to the long transmission distance of UHV AC transmission lines and the complex climatic conditions in the areas they pass through, they are very prone to serious icing. Since the ground wire has no load current, the thickness of the ice on it will far exceed that of the conductor, which can easily cause safety accidents such as ground wire breakage. For this reason, relevant transmission lines use the method of connecting to an ice-melting device to melt the ice on the ground wire. However, lightning strikes, short circuits of UHV conductors to the ground, etc. will generate high-amplitude overvoltages on the ground wire, affecting the normal and stable operation of the ice-melting device. Summary of the invention

[0004] In order to solve the above technical problem or at least partially solve the above technical problem, the present disclosure provides an overvoltage suppression system.

[0005] The present disclosure provides an overvoltage suppression system, comprising: a controller, an ice melting device, a voltage measuring element, a ground wire, a first discharge component, and a second discharge component;

[0006] The controller is connected to the ice melting device; the voltage measuring element is respectively connected to the controller and the ground wire; the output end of the ice melting device is connected to one end of the ground wire, and the other end of the ground wire is grounded; the first discharge component and the second discharge component are both connected to the ground wire;

[0007] The first discharge component is used to discharge the lightning overvoltage of the ground wire to the ground, the second discharge component is used to discharge the conductor overvoltage of the ground wire to the ground, and the controller is used to start the ice melting device to melt the ground wire based on the voltage measuring element measuring that the voltage of the ground wire is within a set voltage range.

[0008] Optionally, the overvoltage suppression system further includes a plurality of towers;

[0009] Each of the pole towers is connected to the ground wire via the first discharge assembly.

[0010] Optionally, the first discharge assembly includes an insulator and a first discharge gap;

[0011] Two ends of the insulator are connected in parallel with the first discharge gap.

[0012] Optionally, a 50% breakdown voltage of the insulator and a 50% breakdown voltage of the first discharge gap satisfy:

[0013] U 50％，G ≤U 50％，P ×0.835;

[0014] Among them, U 50，G represents the 50% breakdown voltage of the first discharge gap, U 50％，P Indicates the 50% breakdown voltage of the insulator.

[0015] Optionally, the gap distance in the first discharge gap is 28.5 cm to 40 cm.

[0016] Optionally, the second discharge assembly includes a lightning arrester and a second discharge gap;

[0017] The second discharge gap is connected in parallel at two ends of the arrester.

[0018] Optionally, there are multiple lightning arresters;

[0019] Two adjacent lightning arresters are connected to the ground in parallel, and the 4 / 10μs current carrying capacity of a single lightning arrester is greater than 100kA.

[0020] Optionally, the second discharge gap comprises two needle-shaped electrodes;

[0021] The tip radius of the needle-shaped electrode is 5 mm to 7 mm.

[0022] Optionally, the overvoltage suppression system further includes a fuse protector;

[0023] The fuse protector is connected to the output end of the ice melting device;

[0024] The fuse protector is used to control the circuit where the ice melting device is located to be disconnected based on the short-circuit current of the ice melting device exceeding the current threshold and the duration of the short-circuit current reaching the set duration.

[0025] Optionally, the first discharge assembly and the second discharge assembly both include a discharge gap; the discharge gap includes two electrodes;

[0026] The lateral staggered distance between two electrodes in the discharge gap is greater than or equal to 1 cm, and / or the discharge gap is provided with an anti-icing cover.

[0027] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0028] The overvoltage suppression system provided by the embodiment of the present disclosure includes: a controller, an ice-melting device, a voltage measuring element, a ground wire, a first discharge component and a second discharge component; the controller is connected to the ice-melting device; the voltage measuring element is respectively connected to the controller and the ground wire; the output end of the ice-melting device is connected to one end of the ground wire, and the other end of the ground wire is grounded; the first discharge component and the second discharge component are both connected to the ground wire; the first discharge component is used to discharge the lightning overvoltage of the ground wire to the ground, and the second discharge component is used to discharge the conductor overvoltage of the ground wire to the ground, and the controller is used to start the ice-melting device to melt the ground wire based on the voltage measuring element measuring that the voltage of the ground wire is within the set voltage range. In this way, by discharging the lightning overvoltage and the conductor overvoltage to the ground respectively, the overvoltage on the ground wire is suppressed, so as to help the voltage of the ground wire be within the set voltage range, and further start the ice-melting device to achieve normal and stable operation of the ice-melting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0031] Figure 1 A schematic diagram of the structure of an overvoltage suppression system provided by an embodiment of the present disclosure;

[0032] Figure 2 A schematic diagram of the structure of another overvoltage suppression system provided by an embodiment of the present disclosure;

[0033] Figure 3 A schematic structural diagram of a first discharge assembly provided in an embodiment of the present disclosure;

[0034] Figure 4 A schematic structural diagram of a second discharge assembly provided in an embodiment of the present disclosure.

[0035] Among them, 100, cable; 110, controller; 120, ice melting device; 121, power supply; 122, ice melting knife switch; 130, voltage measuring element; 151, insulator; 152, first discharge gap; 140, ground wire; 150, first discharge component; 160, second discharge component; 161, lightning arrester; 162, second discharge gap; 1621, needle electrode; 170, pole tower; 190, anti-icing cover. DETAILED DESCRIPTION

[0036] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0037] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0038] The overvoltage suppression system provided by the embodiments of the present disclosure is exemplarily described below in conjunction with the accompanying drawings.

[0039] Figure 1 This is a schematic diagram of the structure of an overvoltage suppression system provided by an embodiment of the present disclosure. Figure 1 The overvoltage suppression system includes: a controller 110, an ice melting device 120, a voltage measuring element 130, a ground wire 140, a first discharge component 150 and a second discharge component 160; the controller 110 is connected to the ice melting device 120; the voltage measuring element 130 is respectively connected to the controller 110 and the ground wire 140; the output end of the ice melting device 120 is connected to one end of the ground wire 140, and the other end of the ground wire 140 is grounded; the first discharge component 150 and the second discharge component 160 are both connected to the ground wire 140; the first discharge component 150 is used to discharge the lightning overvoltage of the ground wire 140 to the ground, and the second discharge component 160 is used to discharge the conductor overvoltage of the ground wire 140 to the ground, and the controller 110 is used to start the ice melting device 120 to melt the ground wire based on the voltage of the ground wire 140 measured by the voltage measuring element 130 being within the set voltage range.

[0040] The ice melting device 120 is a device for melting ice on the ground wire by outputting a DC voltage. For example, the ice melting device 120 may include a power supply for outputting a DC voltage and an ice melting knife switch for performing a switch function. The specific structure of the ice melting device 120 may be set according to the ice melting requirements of the embodiment of the present disclosure, which is not limited here.

[0041] The voltage measuring element 130 is an element for measuring the voltage on the ground line 140. For example, the voltage measuring element 130 may be a voltage sensor, which is not limited herein.

[0042] Among them, the conductor overvoltage refers to the overvoltage generated by the conductor to the ground wire. Specifically, the conductor can generate at least two kinds of overvoltages to the ground wire 140. One kind of conductor overvoltage is a steady-state induced overvoltage formed between the conductor and the ground wire 140 based on the principle of electromagnetic induction, that is, when current passes through the conductor, an alternating magnetic field will be generated in the surrounding space. Since the conductor and the ground wire 140 are close to each other, electromagnetic induction (i.e. mutual induction) occurs between the two, so that the conductor generates a continuous steady-state induced overvoltage to the ground wire 140; the other kind of conductor overvoltage is a discharge overvoltage formed by a short-circuit discharge of the conductor to the ground wire 140, that is, when the ground wire 140 falls off due to ice melting, the distance between the ground wire 140 and the conductor will be shortened, which can easily cause the air gap between the conductor and the ground wire 140 to be broken down, so that the current will flow from the conductor to the ground wire 140 through the arc channel formed by the air, forming a short-circuit discharge, and correspondingly, a discharge overvoltage is generated on the ground wire 140.

[0043] The lightning overvoltage refers to the overvoltage generated by lightning on the ground wire 140. Specifically, when lightning directly hits the ground wire 140, the lightning current will quickly flow into the earth through the ground wire 140. Since the resistance and inductance of the ground wire 140 are very small, the lightning current will flow through the ground wire 140 in a short time, causing the voltage on the ground wire 140 to rise sharply, thereby generating a lightning overvoltage on the ground wire 140.

[0044] Among them, the conductor overvoltage is smaller than the lightning overvoltage, for example, the conductor overvoltage can be tens of kilovolts, while the lightning overvoltage can be hundreds of kilovolts.

[0045] Specifically, by using the first discharge component 150 to discharge the lightning overvoltage of the ground wire 140 to the ground, and using the second discharge component 160 to discharge the conductor overvoltage of the ground wire 140 to the ground, the overvoltage on the ground wire 140 is suppressed, so that there will be no large voltage on the ground wire 140, and then the voltage of the ground wire 140 can be within the set voltage range. Based on this, the controller 110 can start the ice melting device 120 to protect the ice melting device 120 from damage by overvoltage, so as to achieve normal and stable operation of the ice melting device 120.

[0046] In the prior art, in order to suppress overvoltage of the conductor, the conductor is often powered off before the ground wire melts, but the capacity of the UHV conductor is large, and the power outage of the conductor affects the normal power supply of the power grid. The embodiment of the present disclosure utilizes the discharge function of the second discharge component 160 to avoid the loss caused by the power outage of the conductor.

[0047] It can be understood that the set voltage range is a safe voltage range that will not trigger electrical accidents. Electrical accidents include but are not limited to: system failures, device or component damage, etc. The set voltage range can be reasonably set according to the normal voltage of the ground wire. The specific size of the set voltage range is not limited here.

[0048] The overvoltage suppression system provided by the embodiment of the present disclosure includes: a controller 110, an ice melting device 120, a voltage measuring element 130, a ground wire 140, a first discharge component 150 and a second discharge component 160; the controller 110 is connected to the ice melting device 120; the voltage measuring element 130 is respectively connected to the controller 110 and the ground wire 140; the output end of the ice melting device 120 is connected to one end of the ground wire 140, and the other end of the ground wire 140 is grounded; the first discharge component 150 and the second discharge component 160 are both connected to the ground wire 140; the first discharge component 150 is used to discharge the lightning overvoltage of the ground wire 140 to the ground, and the second discharge component 160 is used to discharge the conductor overvoltage of the ground wire 140 to the ground, and the controller 110 is used to start the ice melting device 120 to melt the ground wire based on the voltage of the ground wire 140 measured by the voltage measuring element 130 being within a set voltage range. In this way, by discharging the lightning overvoltage and the conductor overvoltage to the ground respectively, the overvoltage on the ground wire 140 is suppressed, so as to help the voltage of the ground wire 140 be within the set voltage range, further start the ice melting device 120, and realize the normal and stable operation of the ice melting device 120.

[0049] In some embodiments, Figure 2 A schematic diagram of another overvoltage suppression system provided by an embodiment of the present disclosure, in which Figure 1 Based on Figure 2 The overvoltage suppression system further includes a plurality of pole towers 170 ; each pole tower 170 is connected to the ground wire 140 via a first discharge assembly 150 .

[0050] The tower 170 is a structure for supporting the conductors, the ground wire 140 and other electrical equipment. Figure 2 It is exemplarily shown that the ice melting device 120 has two output ends, each of which is connected to the ground line 140 in a one-to-one correspondence, and both ends of the tower 170 are connected to a corresponding ground line 140 through a first discharge assembly 150 .

[0051] Specifically, on the basis that each pole tower 170 is connected to the ground wire 140 through the first discharge assembly 150, the lightning overvoltage of the ground wire 140 can reach the ground through the pole tower 170. The pole tower 170 is equivalent to assisting in discharging the lightning overvoltage to the ground. The specific discharge process of the lightning overvoltage will be exemplified later.

[0052] In some embodiments, reference Figure 2 The ice melting device 120 includes a power supply 121 and an ice melting knife switch 122 ; the ice melting device 120 is connected to a ground wire 140 via a cable 100 .

[0053] For example, the controller 110 may control the ice-melting knife gate 122 to be closed to start the ice-melting device 120 ; or, the controller 110 may control the ice-melting knife gate 122 to be opened to shut down the ice-melting device 120 .

[0054] In some embodiments, Figure 3 A schematic diagram of the structure of a first discharge assembly provided in an embodiment of the present disclosure, based on Figure 1 and Figure 2 , refer to Figure 3 The first discharge assembly 150 includes an insulator 151 and a first discharge gap 152 ; both ends of the insulator 151 are connected in parallel to the first discharge gap 152 .

[0055] Among them, the insulator 151 is a structure for providing electrical insulation. Specifically, in the prior art, the ground wire is often grounded to each pole tower, and cannot be directly powered to melt ice. In this regard, the embodiment of the present disclosure can use the electrical insulation characteristics of the insulator 151 to isolate the ground wire 140 from the pole tower 170, and suspend the ground wire 140, thereby achieving the insulation transformation of the ground wire 140, so that the DC voltage output by the ice melting device 120 is only provided to the ground wire 140 for melting ice, thereby improving the ice melting effect of the ground wire 140.

[0056] The first discharge gap 152 is a structure for lightning protection. Exemplarily, the first discharge gap 152 is usually composed of two rod-shaped electrodes, the head ends of the two electrodes are staggered to form a gap, and the ends of the two electrodes are respectively connected to the insulator 151, so that the first discharge gap 152 and the insulator 151 are connected in parallel.

[0057] Specifically, in thunderstorm weather, if a lightning overvoltage is generated on the ground wire 140, the first discharge gap 152 in parallel with the insulator 151 will discharge, and the ground wire 140 and the pole tower 170 will be briefly connected. Then the lightning current will follow the ground wire 140 and the pole tower 170 to the ground. Since the duration of the lightning current is very short, after the lightning current is discharged to the ground, the lightning overvoltage on the ground wire 140 will become weak or even disappear, thereby preventing lightning from causing structural failures and damages to the insulator 151, the ice melting device 120, etc., and providing safety guarantees for the subsequent normal and stable operation of the ice melting device 120.

[0058] In some embodiments, based on Figure 1 and Figure 2 , continue to refer to Figure 3 , the 50% breakdown voltage of the insulator 151 and the 50% breakdown voltage of the first discharge gap 152 satisfy:

[0059] U 50％，G ≤U 50％，P ×0.835;

[0060] Among them, U 50，G represents the 50% breakdown voltage of the first discharge gap 152, U 50％，P It represents the 50% breakdown voltage of the insulator 151 .

[0061] Among them, the 50% breakdown voltage refers to the voltage value when the probability of a certain component (such as the first discharge gap or insulator) being broken down is 50% under a given breakdown voltage waveform. In other words, under a 50% breakdown voltage, the component has a 50% probability of being broken down and a 50% probability of not being broken down. It can be seen that the 50% breakdown voltage is an important indicator to measure the component's ability to withstand breakdown voltage. It reflects the breakdown characteristics of the component under the action of the breakdown voltage, but it is not a definite threshold. In fact, the breakdown voltage of the component is a random variable, and the 50% breakdown voltage is only the median of its probability distribution.

[0062] According to the above determination, U 50，G It refers to the voltage value when the probability of the first discharge gap 152 being broken down is 50% under a given breakdown voltage waveform, U 50％，P It refers to the voltage value when the probability of the insulator 151 being broken down is 50% under a given breakdown voltage waveform. In particular, 0.835 is a safety factor, which is an empirical value obtained based on the statistical characteristics of the breakdown voltage.

[0063] It should be noted that by setting the 50% breakdown voltage of the insulator 151 and the 50% breakdown voltage of the first discharge gap 152 to meet the above conditions, the breakdown voltage of the first discharge gap 152 is lower than the breakdown voltage of the insulator 151, so that when lightning strikes, the insulator 151 will not break down, but the first discharge gap 152 will be broken down first, and the lightning current will be discharged to the ground, thereby protecting other devices or components in the overvoltage suppression system.

[0064] In addition, since the breakdown voltage of lightning is dispersed, the actual breakdown voltage may be higher or lower than the corresponding 50% breakdown voltage. In order to ensure that the first discharge gap 152 can be broken down preferentially in most cases, a certain safety margin must be reserved. The safety factor of 0.835 times is set based on this dispersion consideration, thereby achieving reliable lightning protection.

[0065] In some embodiments, based on Figure 1 and Figure 2 , continue to refer to Figure 3 The gap distance in the first discharge gap 152 is 28.5 cm to 40 cm.

[0066] The 50% breakdown voltage of the first discharge gap 152 satisfies the following formula:

[0067] U 50，G =23.5×d-552;

[0068] Wherein, d represents the gap distance in the first discharge gap 152, and the unit is centimeter (cm).

[0069] It should be noted that the smaller the gap distance of the discharge gap (such as the first discharge gap), the lower the breakdown voltage, and vice versa. Due to the unified specifications of the engineering community, the power level of the insulator 151 is usually 35kV, and the 50% breakdown voltage of the 35kV insulator is usually set to 435kV. If this value is substituted into the above formula, it can be obtained that d is 42cm. In view of this, in order to ensure that the breakdown voltage of the first discharge gap 152 is low, the embodiment of the present disclosure sets the gap distance in the first discharge gap 152 to be less than 42cm, and is specifically set to: d≤40cm.

[0070] Preferably, the upper limit of the gap distance in the first discharge gap 152 may be 39 cm to 40 cm.

[0071] In addition, it should be noted that the first discharge gap 152 is easily bridged due to ice coating, that is, there is an ice layer in the gap of the first discharge gap 152, which connects the two electrodes, forming an ice bridge between the two electrodes, so that the gap is shortened or disappears. On this basis, if the ice melting device applies a DC voltage to the ground line, it is easy to cause the first discharge gap 152 to short-circuit discharge, and then cause system damage, failure and other problems. In view of this, the embodiment of the present disclosure sets the gap distance d in the first discharge gap 152 to satisfy the following inequality:

[0072]

[0073] Among them, U DC Indicates DC voltage, U FV represents the flashover voltage of the first discharge gap 152.

[0074] Specifically, under normal circumstances, since the DC voltage output by the ice melting device is at most 20 kV, the flashover voltage of the first discharge gap 152 is 0.7 kV / cm, it can be determined that the gap distance d in the first discharge gap 152 is approximately 28.57 cm. To ensure that when a DC voltage is applied to the ground wire, the first discharge gap 152 does not flash over and to avoid short-circuit discharge, the embodiment of the present disclosure is specifically set to: d≥28.5 cm.

[0075] Preferably, the lower limit of the gap distance in the first discharge gap 152 may be 28.5 cm to 29 cm.

[0076] In some embodiments, Figure 4 A schematic diagram of the structure of a second discharge assembly provided in an embodiment of the present disclosure, based on Figure 1 and Figure 2 , refer to Figure 4 The second discharge assembly 160 includes a lightning arrester 161 and a second discharge gap 162; both ends of the lightning arrester 161 are connected in parallel to the second discharge gap 162.

[0077] The arrester 161 is a structure for suppressing the amplitude of the conductor overvoltage, and has a priority suppression function. Specifically, when a conductor overvoltage is generated on the ground line, the arrester 161 will be quickly turned on to discharge the conductor overvoltage to the ground as much as possible, preventing the conductor overvoltage from damaging other structures in the system (such as the ice melting device) without affecting the normal ice melting of the ice melting device.

[0078] It should be noted that the ability of the arrester 161 to suppress the overvoltage of the conductor depends on the current carrying capacity of the arrester 161, that is, the higher the current carrying capacity of the arrester 161, the greater the impact current it can withstand in a short time, that is, the greater the discharge of the overvoltage of the conductor. It can be simply understood as follows: the arrester 161 has a set voltage elimination range for the overvoltage of the conductor. If the overvoltage of the conductor is within the set voltage elimination range, the arrester 161 can be used to eliminate the overvoltage of the conductor. If the overvoltage of the conductor exceeds the set voltage elimination range, the arrester 161 can only eliminate a part of the overvoltage of the conductor. In view of the fact that the above-mentioned current carrying capacity is related to the design characteristics of the arrester 161, the arrester 161 has a limited ability to suppress the overvoltage of the conductor.

[0079] Among them, the second discharge gap 162 is also a structure for limiting the amplitude of the conductor overvoltage, and its current carrying capacity is stronger than the current carrying capacity of the lightning arrester 161, so it has the function of backup protection. Specifically, when the amplitude of the conductor overvoltage is large, that is, the impact current is large and exceeds the current carrying capacity of the lightning arrester 161, the lightning arrester 161 can only discharge a part of the conductor overvoltage to the ground. At this time, the second discharge gap 162 will short-circuit discharge, and discharge the residual conductor overvoltage at the lightning arrester 161 to the ground, protecting the ice melting device and the lightning arrester 161 from damage.

[0080] Exemplarily, when the residual conductor overvoltage at the arrester 161 exceeds 54 kV, the second discharge gap 162 may be short-circuited by discharge breakdown, thereby timely suppressing the conductor overvoltage at both ends of the arrester 161 .

[0081] In this way, by utilizing the arrester 161 and the second discharge gap 162 to cooperatively suppress the overvoltage of the conductor, double protection is provided for the relevant structures in the system, and the overvoltage of the conductor on the ground wire is effectively suppressed, further improving the reliability and safety of the entire system.

[0082] In some embodiments, reference Figure 2 The second discharge assembly 160 is disposed at the output end of the ice melting device 120 .

[0083] Specifically, by arranging the second discharge assembly 160 at the output end of the ice melting device 120, the safety of the ice melting device 120 can be effectively guaranteed while improving the installation convenience of the second discharge assembly 160, which is convenient for subsequent maintenance and care.

[0084] In some embodiments, reference Figure 2 , the number of lightning arresters 161 is multiple; two adjacent lightning arresters 161 are connected to the ground in parallel, and the 4 / 10μs current carrying capacity of a single lightning arrester 161 is greater than 100kA.

[0085] Among them, the 4 / 10μs current-carrying capacity refers to the maximum current peak that the lightning arrester can withstand under the 4 / 10μs impulse current waveform. This waveform simulates the impulse current with a fast rise time. In addition, the 4μs in 4 / 10μs means that the time for the current to rise from zero to the peak is 4 microseconds, and the 10μs means that the time for the current to drop from the peak to 50% of the peak is 10 microseconds.

[0086] As determined above, when the 4 / 10 μs current carrying capacity of a single lightning arrester 161 is greater than 100 kA, it indicates that the lightning arrester 161 can withstand an impulse current peak of up to 100 kA or higher in a very short time (within 4 μs) and has a high current carrying capacity.

[0087] On this basis, considering that the energy of the conductor overvoltage is often large, two adjacent lightning arresters 161 are arranged in parallel, so that the overall current carrying capacity is improved, thereby enhancing the suppression of the conductor overvoltage. Preferably, the lightning arrester 161 can be a 10kV substation lightning arrester.

[0088] At the same time, the second discharge gap 162 also provides effective protection for the two parallel lightning arresters 161. Here, the lightning arrester 161 is not provided with the second discharge gap 162. For example, if the conductor discharges to the ground wire during ice melting, and the generated conductor overvoltage is directly applied to the ground wire, this energy will be extremely huge, which will cause the ice melting device and the two parallel lightning arresters 161 to burst and be damaged. In view of this, the second discharge gap 162 connected in parallel on each lightning arrester 161 in the embodiment of the present disclosure overcomes the above problems. According to the phenomenon of the discharge breakdown short circuit of the second discharge gap 162, the conductor overvoltage at the lightning arrester 161 is well suppressed to prevent each lightning arrester 161 from being damaged by failure. Preferably, the gap distance in the second discharge gap 162 can be 30cm to 36mm.

[0089] In some embodiments, reference Figure 4 The second discharge gap 162 includes two needle-shaped electrodes 1621; the tip radius of the needle-shaped electrode 1621 is 5 mm to 7 mm.

[0090] Specifically, when the electrode in the second discharge gap 162 is set to be needle-shaped and the tip radius of the needle-shaped electrode 1621 is 5mm to 7mm, the needle-shaped electrode 1621 will have a smaller tip radius, which significantly enhances the electric field strength at the tip of the needle-shaped electrode 1621, forming a so-called electric field concentration effect. Under the action of this electric field concentration effect, it helps to reduce the breakdown voltage of the second discharge gap 162 and make its breakdown process more stable, that is, it provides a more consistent electric field distribution, the difference in each breakdown voltage is smaller, and the repeatability and stability of the breakdown voltage are improved.

[0091] In some embodiments, the overvoltage suppression system also includes a fuse protector (not shown in the figure); the fuse protector is connected to the output end of the ice melting device; the fuse protector is used to control the line where the ice melting device is located to be disconnected based on the short-circuit current of the ice melting device exceeding the current threshold and lasting for a set time.

[0092] Specifically, when the output end of the ice-melting device discharges to the ground, the ice-melting device will short-circuit, that is, it will output a large short-circuit current. In this regard, when the short-circuit current of the ice-melting device is relatively large, that is, it exceeds the current threshold, and the duration reaches the set duration, the short-circuit current can be cut off in time by controlling the line where the ice-melting device is located to be disconnected, thereby preventing the ice-melting device from burning.

[0093] Exemplarily, the current threshold may be about five times the rated working current of the ice melting device, and the duration may be 40ms to 50ms or other duration ranges, which may be set according to the protection requirements of the fuse protector and is not limited here.

[0094] In some embodiments, reference Figure 2-Figure 4 The first discharge assembly 150 and the second discharge assembly 160 both include a discharge gap; the discharge gap includes two electrodes; the lateral staggered distance between the two electrodes in the discharge gap is greater than or equal to 1 cm, and / or the discharge gap is provided with an anti-icing cover 190.

[0095] For example, Figure 4 The anti-icing cover 190 shown is for reference. The shape of the anti-icing cover 190 can be semi-cylindrical, and its height can be 8cm to 5cm, and its radius can be 5cm to 3cm. The anti-icing cover 190 of corresponding size and shape can be set according to the actual specifications of the discharge gap. In addition, the material of the anti-icing cover 190 is insulating material such as epoxy resin to avoid safety accidents caused by its own conduction.

[0096] Specifically, the two electrodes in the discharge gap present an interlaced structure. By setting the lateral interlaced distance (represented by d1) between the head ends of the two electrodes in the discharge gap to be greater than or equal to 1 cm, and / or the discharge gap is provided with an anti-icing cover 190, the discharge gap can be prevented from being bridged by ice due to ice covering, thereby ensuring the normal use of the discharge gap.

[0097] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0098] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An overvoltage suppression system, characterized in that: include: A controller, an ice melting device, a voltage measuring element, a ground wire, a first discharge assembly, and a second discharge assembly; The controller is connected to the ice melting device; The voltage measuring element is connected to the controller and the ground wire respectively; the output end of the ice melting device is connected to one end of the ground wire, and the other end of the ground wire is grounded; the first discharge component and the second discharge component are both connected to the ground wire; The first discharge component is used to discharge the lightning overvoltage of the ground wire to the ground, the second discharge component is used to discharge the conductor overvoltage of the ground wire to the ground, and the controller is used to start the ice melting device to melt the ground wire based on the voltage measuring element measuring that the voltage of the ground wire is within a set voltage range.

2. The overvoltage suppression system according to claim 1, characterized in that: Also includes multiple pole towers; Each of the pole towers is connected to the ground wire via the first discharge assembly.

3. The overvoltage suppression system according to claim 1, characterized in that: The first discharge assembly includes an insulator and a first discharge gap; Two ends of the insulator are connected in parallel with the first discharge gap.

4. The overvoltage suppression system according to claim 3, characterized in that: The 50% breakdown voltage of the insulator and the 50% breakdown voltage of the first discharge gap satisfy: IN 50％，G ≤U 50％，P ×0.835; Among them, U 50，G represents the 50% breakdown voltage of the first discharge gap, U 50％，P Indicates the 50% breakdown voltage of the insulator.

5. The overvoltage suppression system according to claim 3, characterized in that: The gap distance in the first discharge gap is 28.5 cm to 40 cm.

6. The overvoltage suppression system according to claim 1, characterized in that: The second discharge assembly includes a lightning arrester and a second discharge gap; The second discharge gap is connected in parallel at two ends of the arrester.

7. The overvoltage suppression system according to claim 6, characterized in that: The number of the lightning arresters is multiple; Two adjacent lightning arresters are connected to the ground in parallel, and the 4 / 10μs current carrying capacity of a single lightning arrester is greater than 100kA.

8. The overvoltage suppression system according to claim 6, characterized in that: The second discharge gap includes two needle-shaped electrodes; The tip radius of the needle-shaped electrode is 5 mm to 7 mm.

9. The overvoltage suppression system according to claim 1, characterized in that: Also includes a fuse protector; The fuse protector is connected to the output end of the ice melting device; The fuse protector is used to control the circuit where the ice melting device is located to be disconnected based on the short-circuit current of the ice melting device exceeding the current threshold and the duration of the short-circuit current reaching the set duration.

10. The overvoltage suppression system according to claim 1, characterized in that: The first discharge assembly and the second discharge assembly both include a discharge gap; the discharge gap includes two electrodes; The lateral staggered distance between two electrodes in the discharge gap is greater than or equal to 1 cm, and / or the discharge gap is provided with an anti-icing cover.

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