Controllable lightning arrester based on full-control and half-control hybrid switch and control method thereof

Abstract

The invention relates to a full-control and half-control hybrid switch-based controllable lightning arrester and a control method thereof, the full-control and half-control hybrid switch-based controllable lightning arrester comprises a fixed part and a controllable part which are connected in series, the controllable part comprises at least one controllable module, the controllable module comprises a second lightning arrester and a hybrid bypass switch, and the second lightning arrester and the hybrid bypass switch are arranged in parallel; the hybrid bypass switch comprises a full-control switch and at least one half-control switch, the full-control switch is connected with the half-control switch in series, the full-control switch is used for controlling the hybrid bypass switch to realize active disconnection, and the half-control switch is used for suppressing overvoltage and consuming energy. The device is compatible with the advantages of rapid switching-on and active switching-off of a full-control switch and a half-control switch, has rapid switching-on and active switching-off capabilities, can break through the inhibition capability limit of a traditional controllable lightning arrester, realizes decoupling voltage limiting and energy consumption, and inhibits transient overvoltage in a deeper manner.

Description

Technical Field

[0001] The present application relates to the technical field of lightning arrester control in a direct current transmission system, and in particular to a controllable lightning arrester based on a fully controlled and half-controlled hybrid switch and a control method thereof. Background Art

[0002] As the voltage level of the power system increases significantly, its overvoltage level increases rapidly. However, power electronic devices in the power system are very sensitive to overvoltage, resulting in low voltage utilization and high cost of power electronic devices. Especially in high-altitude areas, due to the thin air, low atmospheric pressure and density, and reduced electrical strength of the air, the insulation of power equipment becomes very fragile. In order to ensure the economy of power grid construction and the reliability of power transmission, overvoltage needs to be deeply suppressed. In high-voltage DC projects, overvoltage on the DC side is mainly suppressed by lightning arresters. However, in order to ensure the reliability of the lightning arrester, its charge rate cannot be too high, which leads to its unsatisfactory protection performance.

[0003] In addition, DC energy dissipation devices are often used to deeply suppress overvoltage on the DC side, which can limit overvoltage to below 1.1pu, and the overvoltage suppression effect is very good. However, by absorbing the system surplus power to reduce the overvoltage level, it is only suitable for suppressing overvoltages with very low voltage rise rate and long peak time, such as overvoltages with peak time of hundreds of milliseconds generated on the DC side by short-circuit faults on the AC side of flexible DC systems, but it cannot suppress overvoltages with very high voltage rise rate, such as overvoltages with peak time of tens of microseconds generated on the non-fault pole by short-circuit on the DC side of flexible DC systems. At the same time, its use of a large number of fully controlled power electronic devices and independent water cooling systems increases its cost.

[0004] In view of the above problems, a controllable lightning arrester device composed of a controllable part and a fixed part in cascade is further adopted, wherein the fixed part mainly includes a lightning arrester, and the controllable part mainly consists of a lightning arrester and a bypass switch in parallel. It decouples the charge rate and transient pressure ratio by reducing the number of lightning arresters connected to the system when an overvoltage occurs in the system, and finally achieves deep suppression of overvoltage, which has the advantages of low cost, low voltage and current change rate, and good electromagnetic compatibility. However, at present, the semi-controlled switch can only turn on the bypass controllable part but cannot be disconnected, which causes the controllable lightning arrester to be able to be put into operation but not withdrawn. To avoid this problem, the rated voltage of the fixed part lightning arrester needs to be high enough, but this sacrifices the suppression ability of the controllable lightning arrester. This makes it possible for the lightning arrester to pass current even if the rated voltage of the power system is restored. Therefore, the voltage suppression ability of the existing controllable lightning arrester is limited, and it cannot achieve safe and reliable overvoltage suppression. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the present application provides a controllable lightning protection device based on a full-control and half-control hybrid switch and a control method thereof, which specifically adopts the following technical solutions:

[0006] A controllable lightning arrester based on a full-control and half-control hybrid switch, comprising a fixed part and a controllable part connected in series, wherein the fixed part comprises a first lightning arrester, the controllable part comprises at least one controllable module, the controllable module comprises a second lightning arrester and a hybrid bypass switch, and the second lightning arrester and the hybrid bypass switch are arranged in parallel;

[0007] The hybrid bypass switch includes a fully controlled switch and at least one half-controlled switch, wherein the fully controlled switch is connected in series with the half-controlled switch, the fully controlled switch is used to control the hybrid bypass switch to achieve active disconnection, and the half-controlled switch is used to suppress overvoltage and consume energy.

[0008] Optional: The fully controlled switch adopts an insulated gate bipolar transistor, and the gate of the insulated gate bipolar transistor controls the on-off state based on a voltage signal. When the voltage in the power system is normal, the insulated gate bipolar transistor is in the on state; when the voltage in the power system drops from an overvoltage state to a first preset threshold, the insulated gate bipolar transistor is in the off state.

[0009] Optional: The semi-controlled switch adopts a gap switch, and the controllable gap switch changes the on-off state based on voltage signal control or voltage changes. When the voltage in the power system is normal, the gap switch is in the off state; when the voltage in the power system is in an overvoltage state, the gap switch is in the on state.

[0010] Optional: The half-controlled switch uses a thyristor, which controls the on and off state based on a voltage signal. When the voltage in the power system is in a normal state, the thyristor is in an off state; when the voltage in the power system is in an overvoltage state, the thyristor is in an on state.

[0011] Optional: The semi-controlled switch uses a gap switch in parallel with a thyristor, and changes the on-off state of the gap switch through voltage signal control or voltage changes, and controls the on-off state of the thyristor through a voltage signal. When the voltage in the power system is in a normal state, the gap switch and the thyristor are both in an off state; when the voltage in the power system is in an overvoltage state, at least one of the gap switch or the thyristor is in an on state.

[0012] Optional: The rated voltage of the fixed part of the controllable lightning protection device must meet the following requirements:

[0013]

[0014] Where V R_Fixedis the rated voltage of the fixed arrester; V DC is the rated operating voltage of the power system; S Project is the charging rate of the arrester in the project; The design target for the device's pressure limiting level; It is the maximum value of the fast wave front overvoltage in the project.

[0015] Optional: The overall rated voltage of the controllable lightning protection device must meet the following requirements:

[0016]

[0017] Where V R is the overall rated voltage of the controllable lightning protection device; V DC is the rated operating voltage of the power system; S is the charge rate of the lightning arrester in the controllable lightning protection device, where S≥0.6.

[0018] Optional: The rated voltage of the controllable part of the controllable lightning protection device must meet the following requirements:

[0019] V R_Changed =V R -V R_Fixed ;

[0020] Where V R_Changed is the rated voltage of the controllable part; V R is the overall rated voltage of the controllable lightning protection device; V R_Fixed It is the rated voltage of the fixed arrester.

[0021] Optionally: the first lightning arrester and the second lightning arrester are both metal oxide lightning arresters.

[0022] Furthermore, the present application also discloses a control method of a controllable lightning protection device based on a full-control and half-control hybrid switch, the method comprising the following steps:

[0023] When the power system is operating normally, the controllable lightning arrester does not work. At this time, the full-control switch is in the normally on state, and the half-control switch is in the off state;

[0024] When the power system enters an overvoltage state and the voltage of the power system exceeds the safety threshold, the half-controlled switch is quickly turned on, the hybrid bypass switch is closed, the controllable part is put into operation, and the overvoltage is continuously suppressed;

[0025] When the overvoltage is suppressed and the power system voltage drops to the first preset threshold, the fully-controlled switch is quickly disconnected, the hybrid bypass switch is opened, and the half-controlled switch is disconnected after the current flowing through it decreases to zero. The controllable part is disconnected and cut out, and the controllable lightning protection device stops consuming energy.

[0026] Beneficial Effects

[0027] The technical solution of this application has the following beneficial effects:

[0028] (1) The controllable lightning arrester of the present application is composed of a mixed combination of a fully controlled switch and a semi-controlled switch, and has excellent compatibility with the advantages of rapid activation and active disconnection of the two. It has the ability to quickly activate and actively exit, which can break through the suppression capacity limit of traditional controllable lightning arresters, achieve decoupling of voltage limiting and energy consumption, and more deeply suppress transient overvoltages. While achieving higher suppression performance, it can also reduce the size, weight and cost of the device, so that the device has broad application prospects in flexible DC systems such as lightweight offshore converter platforms that urgently need deep transient overvoltage suppression.

[0029] (2) The fully controlled switch in the controllable lightning arrester of the present application mainly includes fully controlled devices such as IGBT to realize the active disconnection capability of the bypass switch, breaking through the voltage limit of the device, and at the same time enabling the device to have the exit capability to decouple the voltage limit and energy consumption during the overvoltage process, greatly reducing the number of parallel columns of the lightning arrester, reducing the size, weight and cost of the equipment, and improving reliability; and the semi-controlled switch adopts gap, thyristor or parallel connection of the two solutions, which can ensure that the controllable lightning arrester has both anti-interference and fast and reliable input capabilities, further improving the reliability and safety of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of the controllable lightning protection device in the embodiment of the present application.

[0031] Figure 2 Schematic diagram of voltage change when the controllable lightning protection device in the embodiment of the present application performs overvoltage suppression.

[0032] Figure 3 This is a schematic diagram of the internal operation of the controllable lightning protection device in the embodiment of the present application when overvoltage is suppressed. Figure 3 (a) is a schematic diagram of the operation of the controllable lightning protection device under normal operating conditions; Figure 3 (b) is a schematic diagram of the semi-controlled switch action when entering the overvoltage state; Figure 3 (c) is a schematic diagram of the fully controlled switch operation after the overvoltage is suppressed; Figure 3 (d) is a schematic diagram of the half-controlled switch operation after the overvoltage is suppressed.

[0033] Figure 4 This is a structural diagram of an electronic device in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The present application is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and cannot be used to limit the scope of protection of the present application. It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present application.

[0035] Combination Figure 1 As shown, the embodiment of the present application specifically discloses a controllable lightning protection device based on a fully controlled and half-controlled hybrid switch, which includes a fixed part I and a controllable part II connected in series, wherein the fixed part I includes a first lightning arrester 4, and the controllable part II includes at least one controllable module, and the controllable module includes a second lightning arrester 3 and a hybrid bypass switch, and the second lightning arrester 3 and the hybrid bypass switch are arranged in parallel; the controllable lightning protection device turns on the hybrid bypass switch when an overvoltage occurs in the power system to reduce the number of lightning arresters connected to the power system to decouple the charge rate and the transient pressure ratio, thereby ultimately achieving deep suppression of overvoltage. The device has the advantages of low cost, low voltage and current change rate, and good electromagnetic compatibility. At the same time, in order to ensure fast and reliable action and anti-interference in overvoltage suppression, the hybrid bypass switch usually adopts technologies such as thyristor 2 and gap switch to significantly improve the action speed of the hybrid bypass switch. Preferably, in the present application, the first lightning arrester 4 and the second lightning arrester 3 both use metal oxide lightning arresters.

[0036] It should be further explained that the current traditional controllable lightning arrester is generally composed of a controllable part II and a fixed part I in cascade, the fixed part I mainly includes the first lightning arrester 4, and the controllable part II is mainly composed of the second lightning arrester 3 and the hybrid bypass switch in parallel. However, the controllable part II can only turn on the hybrid bypass switch but cannot be disconnected, which results in the controllable lightning arrester being able to be put into operation but not withdrawn. In order to solve the above problems, the present application adopts a combination of a fully controlled switch and a semi-controlled switch, which can take into account both rapid action and flexible withdrawal, breaking through the limit of the voltage suppression capability of the controllable lightning arrester, and decoupling voltage suppression and energy consumption.

[0037] Specifically, the hybrid bypass switch described in the present application includes a fully-controlled switch and at least one half-controlled switch, wherein the fully-controlled switch is connected in series with the half-controlled switch, the fully-controlled switch is used to control the hybrid bypass switch to achieve active disconnection, and the half-controlled switch is used to control the switching action of the second lightning arrester 3 to suppress overvoltage and consume energy.

[0038] As a preferred method, the fully controlled switch of the present application can use an insulated gate bipolar transistor, and the gate of the insulated gate bipolar transistor controls the on-off state based on a voltage signal. When the voltage in the power system is normal, the insulated gate bipolar transistor is in the on state; when the voltage in the power system drops from an overvoltage state to a first preset threshold, the insulated gate bipolar transistor is in the off state. Based on the fully controlled switch, the controllable lightning arrester of the present application can take into account the characteristics of fast action and flexible exit.

[0039] Furthermore, the lightning arrester in the power system needs to ensure that the arrester presents high impedance under normal operation, and when overvoltage occurs in the power system, the impedance characteristics of the arrester are quickly changed to make it present low impedance, so as to discharge the overvoltage current into the ground, thereby protecting the electrical equipment. The controllable part II needs to be adjusted in real time according to the voltage, current and other parameters of the power system to achieve accurate control and protection of overvoltage. The semi-controlled switch described in this application can adopt the form of gap switch 1, thyristor 2 or a combination of the two. The purpose of the semi-controlled switch is to control the switching quantity of the second arrester 3, and then control the impedance state of the controllable part II to achieve overvoltage suppression.

[0040] Preferably, when the semi-controlled switch adopts the gap switch 1, under normal circumstances, a certain gap is maintained between the two electrodes of the gap switch 1, and the controllable gap switch 1 is in an off state. When the circuit needs to be connected, by applying a specific voltage or current signal, by changing the gap environment (such as air pressure, temperature, distance, etc.), the gap between the electrodes is broken down, thereby realizing the conduction of the circuit, for example, the gap switch includes a breakdown gap switch, a controllable gap switch, etc. When the voltage is about to reach a certain value, the gap between the electrodes gradually restores the insulation state, and then becomes disconnected. The gap switch 1 described in this application changes the on-off state based on the voltage signal control or voltage change of the power system. When the voltage in the power system is normal, the gap switch 1 is in an off state, at which time the current flows to the second lightning arrester 3 of the controllable part II, and the controllable lightning arrester as a whole presents a high impedance; when the voltage in the power system is in an overvoltage state, the gap switch 1 is in a conducting state, at which time the current flows to the gap switch 1, and the controllable lightning arrester as a whole presents a low impedance.

[0041] As an alternative, the semi-controlled switch of the present application can also use thyristor 2. When the gate of thyristor 2 is not triggered by a trigger signal, thyristor 2 is in a blocking state; when an appropriate trigger signal is added to the gate, thyristor 2 is triggered to turn on, and current can flow from the anode to the cathode. And once thyristor 2 is turned on, even if the gate trigger signal is removed, it can still maintain the on state. Only when the anode current decreases to less than the holding current or the voltage between the anode and the cathode is reversed, thyristor 2 will be turned off. Based on the above characteristics, the semi-controlled switch of the present application uses thyristor 2, which controls the on-off state based on the voltage signal applied to the gate by the power system. When the voltage in the power system is in a normal state, the thyristor 2 is in an off state, at which time the current flows to the second lightning arrester 3 of the controllable part II, and the controllable lightning arrester as a whole presents a high impedance; when the voltage in the power system is in an overvoltage state, the thyristor 2 is in a conducting state, at which time the current flows to the thyristor 2, and the controllable lightning arrester as a whole presents a low impedance.

[0042] As another alternative, the semi-controlled switch of the present application can also adopt the method of connecting the gap switch 1 and the thyristor 2 in parallel, which combines the characteristics of the gap switch 1 and the thyristor 2 to form a double insurance, and controls the on-off state of the gap switch 1 by the voltage signal of the power system or based on the voltage change, and controls the on-off state of the thyristor 2 by the voltage signal. When the voltage in the power system is in a normal state, the gap switch 1 and the thyristor 2 are both in the off state. At this time, the current flows to the second lightning arrester 3 of the controllable part II, and the controllable lightning protection device as a whole presents a high impedance; when the voltage in the power system is in an overvoltage state, at least one of the gap switch 1 or the thyristor 2 is in the on state. At this time, the current flows to the conductive device, and the controllable lightning protection device as a whole presents a low impedance.

[0043] Furthermore, the rated voltage (V R_Fixed ) determines the overvoltage peak value in the deep voltage suppression stage and reflects the voltage limiting capability. The rated voltage of the fixed part of the controllable lightning protection device must meet the following requirements:

[0044]

[0045] Where V R_Fixed is the rated voltage of the fixed arrester; V DC is the rated operating voltage of the power system; S Project is the charging rate of the arrester in the project; The design target for the device's pressure limiting level; It is the maximum value of the fast wave front overvoltage in the project.

[0046] Furthermore, due to the overall rated voltage (V R ) It is necessary to ensure that the leakage current and active power loss of the device are small when the power system is operating normally, so as to ensure that the device has good aging performance and high reliability, and the overall rated voltage has almost nothing to do with the voltage limiting effect of the lightning arrester. Therefore, the charge factor S of the lightning arrester in the controllable lightning arrester proposed in this application can be very low, but this will also increase the rated voltage of the lightning arrester in the controllable part II and the maximum voltage borne by the controllable part II, resulting in an increase in the cost of the controllable part II. Therefore, considering the economy, the charge factor S should not be too low, and the charge factor S is generally set to ≥ 0.6. At the same time, the overall rated voltage of the controllable lightning arrester must meet the following conditions:

[0047]

[0048] Where V R is the overall rated voltage of the controllable lightning protection device; V DC is the rated operating voltage of the power system; S is the charge rate of the lightning arrester in the controllable lightning protection device.

[0049] Based on the overall rated voltage of the controllable lightning arrester and the rated voltage of the fixed part, it can be further determined that the rated voltage of the controllable part of the controllable lightning arrester must meet the following conditions:

[0050] V R_Changed =V R -V R_Fixed ;

[0051] Where V R_Changed is the rated voltage of the controllable part; V R is the overall rated voltage of the controllable lightning protection device; V R_Fixed It is the rated voltage of the fixed arrester.

[0052] Further, combined with Figure 2 and Figure 3 As shown, the present application also discloses a control method for a controllable lightning protection device based on a full-control and half-control hybrid switch, the method comprising the following steps:

[0053] like Figure 3 As shown in (a), when the power system is operating normally, that is, during the T1 period, the voltage of the fixed part I is monitored in real time. At this time, the monitoring value does not exceed the safety threshold, and the controllable lightning arrester does not work. At this time, the full-controlled switch is in the normally open state, and the half-controlled switch is in the disconnected state;

[0054] like Figure 3 As shown in (b), when the power system enters the overvoltage state, that is, the T2 period, and the voltage of the power system exceeds the safety threshold, the half-controlled switch is quickly turned on, at which time the hybrid bypass switch is closed, and the hybrid bypass switch of the controllable part II is put into operation to start continuously suppressing the overvoltage;

[0055] like Figure 3 As shown in (c), when the overvoltage is suppressed and the power system voltage drops to the first preset threshold, that is, during the T3 period, the fully controlled switch is quickly disconnected, at which time the hybrid bypass switch is opened, and the half-controlled switch is disconnected after the current flowing through it decreases to zero, as shown in FIG. Figure 3 As shown in (d), at this time, the controllable part II is disconnected and the controllable lightning protection device stops consuming energy. When the power system voltage returns to normal, the fully controlled switch returns to the normally open state.

[0056] like Figure 4 As shown, the embodiment of the present application also provides an electronic device, including a processor 701, a memory 702 and a bus 703, wherein the processor 701 and the memory 702 communicate with each other through the bus 703; and a program or instruction stored in the memory 702 and executable on the processor 701, which is executed by the processor 701 to implement the following Figure 1The various processes of the method embodiment shown in the figure can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0057] The embodiment of the present application also provides a readable storage medium on which a program or instruction is stored. When the program or instruction is executed by a processor, the above Figure 1 The various processes of the method embodiments described above can achieve the same technical effect, and will not be described again here to avoid repetition.

[0058] The present application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the above Figure 1 The various processes of the method embodiments described above can achieve the same technical effect, and will not be described again here to avoid repetition.

[0059] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned sequence numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

[0060] It should be noted that, in this article, the terms "include", "comprises" or any other variations 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, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0061] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another device, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0062] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0063] In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be a separate unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0064] A person skilled in the art can understand that all or part of the steps of implementing the above method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, etc., various media that can store program codes.

[0065] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can essentially or in other words, the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a device (which can be a terminal or a platform, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0066] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A controllable lightning protection device based on a full-control and half-control hybrid switch, characterized in that: It comprises a fixed part and a controllable part connected in series, wherein the fixed part comprises a first lightning arrester, the controllable part comprises at least one controllable module, the controllable module comprises a second lightning arrester and a hybrid bypass switch, and the second lightning arrester and the hybrid bypass switch are arranged in parallel; The hybrid bypass switch includes a fully controlled switch and at least one half-controlled switch, wherein the fully controlled switch is connected in series with the half-controlled switch, the fully controlled switch is used to control the hybrid bypass switch to achieve active disconnection, and the half-controlled switch is used to suppress overvoltage and consume energy.

2. The controllable lightning protection device according to claim 1, characterized in that: The fully controlled switch adopts an insulated gate bipolar transistor, and the gate of the insulated gate bipolar transistor controls the on-off state based on a voltage signal. When the voltage in the power system is normal, the insulated gate bipolar transistor is in the on state; when the voltage in the power system drops from an overvoltage state to a first preset threshold, the insulated gate bipolar transistor is in the off state.

3. The controllable lightning protection device according to claim 1, characterized in that: The semi-controlled switch adopts a gap switch, and the gap switch changes the on-off state based on the voltage signal control or the voltage change. When the voltage in the power system is normal, the gap switch is in the off state; When the voltage in the power system is in an overvoltage state, the gap switch is in an on state.

4. The controllable lightning protection device according to claim 1, characterized in that: The half-controlled switch uses a thyristor, which controls the on and off state based on a voltage signal. When the voltage in the power system is in a normal state, the thyristor is in an off state; when the voltage in the power system is in an overvoltage state, the thyristor is in an on state.

5. The controllable lightning protection device according to claim 1, characterized in that: The semi-controlled switch adopts a gap switch connected in parallel with a thyristor, and controls the on-off state of the gap switch by a voltage signal or changes the on-off state based on a voltage change. The on-off state of the thyristor is controlled by a voltage signal. When the voltage in the power system is in a normal state, the gap switch and the thyristor are both in an off state; when the voltage in the power system is in an overvoltage state, at least one of the gap switch or the thyristor is in an on state.

6. The controllable lightning protection device according to claim 1, characterized in that: The rated voltage of the fixed part of the controllable lightning protection device must meet the following requirements: Where V R_Fixed is the rated voltage of the fixed arrester; V DC is the rated operating voltage of the power system; S Project is the charging rate of the arrester in the project; The design target for the device's pressure limiting level; It is the maximum value of the fast wave front overvoltage in the project.

7. The controllable lightning protection device according to claim 6, characterized in that: The overall rated voltage of the controllable lightning protection device must meet the following requirements: Where V R is the overall rated voltage of the controllable lightning protection device; V DC is the rated operating voltage of the power system; S is the charge rate of the lightning arrester in the controllable lightning protection device, where S≥0.

6.

8. The controllable lightning protection device according to claim 7, characterized in that: The rated voltage of the controllable part of the controllable lightning protection device must meet the following requirements: V R_Changed =V R -V R_Fixed ; Where V R_Changed is the rated voltage of the controllable part; V R is the overall rated voltage of the controllable lightning arrester; V R_Fixed It is the rated voltage of the fixed arrester.

9. The controllable lightning protection device according to claim 1, characterized in that: The first lightning arrester and the second lightning arrester are both metal oxide lightning arresters.

10. A control method for a controllable lightning protection device based on a full-control and half-control hybrid switch, characterized in that: The method comprises the following steps: When the power system is operating normally, the controllable lightning arrester does not work. At this time, the full-control switch is in the normally on state, and the half-control switch is in the off state; When the power system enters an overvoltage state and the voltage of the power system exceeds the safety threshold, the half-controlled switch is quickly turned on, the hybrid bypass switch is closed, the controllable part is put into operation, and the overvoltage is continuously suppressed; When the overvoltage is suppressed and the power system voltage drops to the first preset threshold, the fully-controlled switch is quickly disconnected, the hybrid bypass switch is opened, and the half-controlled switch is disconnected after the current flowing through it decreases to zero. The controllable part is disconnected and cut out, and the controllable lightning protection device stops consuming energy.

Images