A fully solid-state breaking structure for a split conductor online non-stop ice melting device

Abstract

The present invention proposes an all-solid-state disconnecting structure for an online, non-stop de-icing device for split conductors. It consists of a series of multi-unit series-parallel structures corresponding to the sub-conductors of the split conductors. In the multi-unit series-parallel structures, each all-solid-state power unit contains an insulated gate bipolar transistor, an anti-parallel diode, a voltage limiting circuit, and an overvoltage protection device, and synchronized disconnection is achieved by controlling a drive unit. The disconnecting structure is based on IGBTs, constructing a common-emitter circuit breaker topology unit and a passive RCD snubber circuit. The multi-unit series-parallel configuration improves voltage resistance and current carrying capacity, and has the advantages of fast response, high reliability, and good electromagnetic compatibility. It can melt ice without power interruption, replace mechanical switches, avoid mechanical failures, and ensure stable operation in high-voltage environments. This is of great significance for improving the reliability of power grids in harsh climates.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage power transmission, and in particular to a full-solid-state breaking structure for an online non-stop ice-melting device for split conductors. Background Art

[0002] With the continuous expansion of power systems and the widespread distribution of transmission networks, icing of power lines has become a major factor affecting the safe and stable operation of power grids. In winter, under low temperatures and high humidity, ice is very susceptible to formation on transmission lines. This not only increases the mechanical load on the lines but can also cause serious faults such as phase short circuits, tripping, and disconnection, posing a serious threat to the safe operation of the power system.

[0003] In recent years, online, non-stop ice-melting technology has become a research hotspot. Its core goal is to melt ice on split conductors of transmission lines while maintaining normal power supply. This type of technology typically requires a dedicated disconnecting device to inject or remove ice-melting current into or out of the line at specific moments. Traditional disconnecting devices primarily use mechanical circuit breakers, which suffer from slow operation, low reliability, and the susceptibility to arcing. These devices struggle to meet the rapid response and high reliability requirements of online ice-melting.

[0004] It should be noted that the information disclosed in the above background technology section is only used to understand the background of this application, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0005] The main purpose of the present invention is to overcome the defects existing in the above-mentioned background technology and provide a full solid-state disconnecting structure for an online non-stop ice-melting device for splitting conductors.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A fully solid-state breaking structure for a split conductor online non-stop ice melting device, comprising:

[0008] A series of multi-unit series-parallel structures, each multi-unit series-parallel structure being configured corresponding to a sub-conductor in the split conductor, wherein each multi-unit series-parallel structure comprises a plurality of all-solid-state power units connected in series to form a plurality of series branches, and the plurality of series branches are connected in parallel;

[0009] The all-solid-state power unit includes: an anti-parallel topology consisting of a pair of insulated gate bipolar transistors connected with a common emitter and an anti-parallel diode to achieve bidirectional current conduction and blocking; a voltage limiting circuit, comprising an RCD voltage limiting module consisting of a resistor, a capacitor, and a diode, connected in parallel across each insulated gate bipolar transistor; and an overvoltage protection device connected in parallel across each insulated gate bipolar transistor.

[0010] A control drive unit electrically connected to the gate of each insulated gate bipolar transistor, wherein each all-solid-state power unit in the multi-unit series-parallel structure is controlled by the control drive unit to achieve synchronous switching on and off;

[0011] The two ports of each multi-unit series-parallel structure are respectively connected to the two connection points of each sub-conductor of the split conductor and fixed to the conductor connection of the transmission tower.

[0012] Furthermore, in the multi-unit series-parallel structure:

[0013] The number of series branches is determined by the voltage difference when the switch is disconnected to ensure that the voltage of a single all-solid-state power unit is within a safe range;

[0014] The number of parallel branches is determined by the instantaneous maximum current in the ice melting state to increase the system current capacity.

[0015] Furthermore, the voltage difference is calculated according to the following formula:

[0016] ;

[0017] in, is the distance between the short-circuit point on the current conductor and the short-circuit point The voltage difference at is the phase current of the carrier conductor, is the distance to the short-circuit point, is the resistance per unit length of the sub-conductor, It is the inductance of the sub-conductor when one of the sub-conductors is conducting current and the other is interrupted.

[0018] Furthermore, the RCD voltage limiting module parameters satisfy the following formula:

[0019] ;

[0020] Where C is the capacitance value, is the stray inductance in the IGBT turn-off circuit;

[0021] The value of resistance R should satisfy the following formula:

[0022] ;

[0023] in, is the maximum collector current of the IGBT.

[0024] Furthermore, the actual number of the series-parallel branches is 1.5 times the calculated number for redundant configuration.

[0025] Furthermore, the multi-unit series-parallel structure further includes:

[0026] The buffer impedance element connected to each all-solid-state power unit is used to suppress the circulating current and oscillation between the units.

[0027] Furthermore, the control drive unit satisfies:

[0028] The gate control signals output to each insulated gate bipolar transistor in the multi-unit series-parallel structure are synchronized, and the time difference is within a set acceptable error range;

[0029] The gate control signals of all the insulated gate bipolar transistors on the same sub-conductor are the same.

[0030] In some embodiments, the present invention provides an all-solid-state disconnecting structure for a split conductor online non-stop ice melting device, comprising: an all-solid-state power unit, comprising an insulated gate bipolar transistor (IGBT) and an anti-parallel diode connected at a common emitter; a voltage limiting circuit, comprising an RCD voltage limiting structure composed of a resistor, a capacitor, and a diode; an overvoltage protection device; a multi-unit series-parallel structure, wherein the all-solid-state disconnecting structure is intended to be used in high-voltage transmission lines, which have high requirements for both the turn-off voltage and the turn-on current, and thus the multi-unit series-parallel structure comprises a plurality of all-solid-state power units in series and parallel configurations; a control drive unit, electrically connected to a control terminal of the all-solid-state power unit, for providing an isolated drive signal and realizing turn-on and turn-off control;

[0031] Among them, the common-emitter insulated gate bipolar transistor has a bidirectional conduction function, and the series-parallel structure composed of this unit should have two ports, which are respectively connected to the jumper connection of the two split conductors located on the pole tower; the RCD module described in the voltage limiting circuit should be connected in parallel at both ends of each unit, and the number of RCD modules should be exactly the same as the number of anti-parallel power modules; the metal oxide varistor overvoltage protection device is connected in parallel at both ends of each group of all-solid-state power units; the output port of the control drive unit should be aligned with the gate area of ​​the insulated gate bipolar transistor in each anti-parallel power module, and the gate control signals of the same sub-conductor should be the same and the timing should be synchronized, requiring that the time difference from the control signal to the gate should be within an acceptable error range; the disconnecting structure described in this patent should be completely placed in the split conductor online non-stop de-icing device, receive signals from the monitoring module and the main control module of the de-icing device, and be fixed at the connection between the two sections of the conductors of the transmission tower to realize the transfer of de-icing current on the sub-conductor.

[0032] Among them, the all-solid-state power unit includes: a first insulated gate bipolar transistor and a second insulated gate bipolar transistor, a first diode and a second diode; the emitter of the first insulated gate bipolar transistor is connected to the emitter of the second insulated gate bipolar transistor, the cathode of the first diode is connected to the collector of the first insulated gate bipolar transistor, and the cathode of the second diode is connected to the collector of the second insulated gate bipolar transistor, forming an anti-parallel structure; the gates of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor are respectively connected to the control drive unit, for independently receiving control signals with the same timing; the anti-parallel structure can realize bidirectional current conduction and blocking functions, and is suitable for the opening and closing operations of AC circuits.

[0033] In which, the voltage limiting circuit includes: an RCD voltage limiting circuit composed of a resistor, a capacitor and a diode, and the RCD voltage limiting circuit is connected in parallel with the corresponding insulated gate bipolar transistor; wherein, the resistor and the diode are connected in parallel, and in the parallel structure formed, the parallel port on the cathode side of the diode is connected to the capacitor, that is, the parallel structure composed of the resistor and the diode is connected in series with the capacitor to form a complete voltage limiting module; the resistor is used to limit the overvoltage amplitude during the disconnection process, the capacitor is used to absorb transient energy during the disconnection process and control the voltage rise rate, and the diode is used to provide a unidirectional conduction path to ensure capacitor discharge; the impedance parameters of the voltage limiting circuit match the parasitic parameters of the insulated gate bipolar transistor to ensure uniform voltage distribution in the multi-unit structure and improve the system's voltage resistance and reliability.

[0034] The metal oxide varistor is connected in parallel at both ends of each all-solid-state power unit; the rated operating voltage of the metal oxide varistor is higher than the normal operating voltage of the all-solid-state power unit and lower than the maximum withstand voltage value of the all-solid-state power unit; when a transient overvoltage occurs in the system, the metal oxide varistor is turned on to absorb excess energy and limit the voltage amplitude at both ends of the all-solid-state power unit.

[0035] Among them, the multi-unit series-parallel structure includes: multiple all-solid-state power units are connected in series to form multiple series branches, and the multiple series branches are connected in parallel to form a complete breaking unit; the number of all-solid-state power units in each series branch is determined according to the voltage difference under the switch disconnection scenario to ensure that the voltage borne by each all-solid-state power unit is within a safe range; the number of parallel branches is determined according to the instantaneous maximum current that can pass through the sub-conductor in the ice melting state to improve the current carrying capacity of the system; redundancy must also be considered in the series-parallel structure. Since the circuit breaker structure is applied to trunk transmission lines with higher voltage levels, an actual number of series-parallel branches that is 1.5 times the calculated number of series-parallel branches must be applied; each all-solid-state power unit in the multi-unit series-parallel structure is synchronously opened and closed through the control drive unit to ensure uniform distribution of voltage and current; the multi-unit series-parallel structure also includes a buffer impedance element connecting each unit to suppress circulating current and oscillation between units.

[0036] The present invention has the following beneficial effects:

[0037] This invention proposes an all-solid-state disconnecting structure for a split-conductor, online, non-stop de-icing device. This structure utilizes all-solid-state IGBTs as the core power electronic device, constructs the circuit breaker units in an anti-parallel topology, and utilizes a passive RCD circuit to achieve voltage limiting. The invention employs a multi-unit series-parallel configuration scheme, effectively improving the system's withstand voltage and current capacity, adapting to the voltage and current requirements of high-voltage lines. This disconnecting structure offers advantages such as fast response, high reliability, and excellent electromagnetic compatibility. It can achieve de-icing on high-voltage lines without power interruption, resolving the technical challenges of traditional de-icing methods requiring power outages. The all-solid-state disconnecting structure replaces mechanical switches, eliminating the risk of mechanical component aging and arcing, and potentially preventing mechanical switch failures in extreme environments such as cold and humid conditions. Furthermore, the optimized anti-parallel topology and RCD voltage-limiting circuit design ensure stable system operation in high-voltage environments. This invention enables reliable disconnection during the de-icing process on high-voltage lines, ensuring that grid users remain unaware of any power outages, truly achieving "non-stop de-icing." The solution of the present invention provides key support for the online non-stop ice melting technology of transmission lines, and is of great significance for improving the operational reliability of power grids under adverse weather conditions.

[0038] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The basic unit of the IGBT common collector connection in the breaking structure according to the embodiment of the present invention is shown.

[0040] Figure 2The specific topology of the RCD voltage limiting circuit and overvoltage protection device according to the embodiment of the present invention is shown.

[0041] Figure 3 The overall topology of the complete disconnect structure of the embodiment of the present invention is shown.

[0042] Figure 4 An example of arranging the switch structure on a sub-conductor of a four-split conductor according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0043] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope of the present invention and its application.

[0044] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for both fixing and coupling or communication.

[0045] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0047] The present invention proposes a fully solid-state disconnecting structure for an online, non-stop de-icing device for split conductors. Through an anti-parallel IGBT topology, an RCD voltage-limiting circuit, a multi-unit series-parallel configuration, and a control drive unit, reliable disconnection during the de-icing process of high-voltage lines is achieved, providing key support for online, non-stop de-icing technology for transmission lines.

[0048] See Figures 1 to 4An embodiment of the present invention provides an all-solid-state disconnecting structure for a split-conductor, online, non-stop ice-melting device. The structure comprises a control drive unit and a series of multi-unit series-parallel structures. Each multi-unit series-parallel structure corresponds to a sub-conductor in a split conductor. Within each multi-unit series-parallel structure, multiple all-solid-state power units are connected in series to form multiple series branches, which are then connected in parallel. The all-solid-state power units comprise an anti-parallel topology consisting of a pair of common-emitter-connected insulated gate bipolar transistors (IGBTs) and anti-parallel diodes to enable bidirectional current conduction and blocking; a voltage-limiting circuit comprising an RCD voltage-limiting module composed of a resistor R, a capacitor C, and a diode D, connected in parallel across each IGBT; and an overvoltage protection device connected in parallel across each IGBT. Based on the IGBT, the disconnecting structure constructs a common-emitter circuit breaker topology unit and a passive RCD snubber circuit. The multi-unit series-parallel configuration improves withstand voltage and current capacity. The control drive unit is electrically connected to the gates of each insulated gate bipolar transistor. Each all-solid-state power unit in the multi-unit series-parallel structure is controlled by the control drive unit to achieve synchronous switching. The two ports of each multi-unit series-parallel structure are connected to two split conductors located at the jumper string on the transmission tower.

[0049] In some embodiments, the gate control signals output by the control driving unit to each insulated gate bipolar transistor in the multi-unit series-parallel structure are synchronized, and the time difference is within a set acceptable error range; the gate control signals of all insulated gate bipolar transistors on the same sub-conductor are the same.

[0050] In some embodiments, the all-solid-state power unit includes a first insulated gate bipolar transistor IGBT1, a second insulated gate bipolar transistor IGBT2, a first diode D1 and a second diode D2; the emitters of the first insulated gate bipolar transistor IGBT1 and the second insulated gate bipolar transistor IGBT2 are connected in common, the cathode of the first diode D1 is connected to the collector of the first insulated gate bipolar transistor IGBT1, and the cathode of the second diode D2 is connected to the collector of the second insulated gate bipolar transistor IGBT2, forming an anti-parallel bidirectional conduction structure; the gates of the first insulated gate bipolar transistor IGBT1 and the second insulated gate bipolar transistor IGBT2 are independently connected to the control drive unit.

[0051] In some embodiments, in the RCD voltage limiting module: a resistor R and a diode D are connected in parallel to form a parallel structure, and a capacitor C is connected in series to the cathode side port of the diode in the parallel structure; the resistor is used to limit the overvoltage amplitude, the capacitor is used to absorb transient energy and control the voltage rise rate, and the diode provides a capacitor discharge path.

[0052] In some embodiments, the overvoltage protection device is a metal oxide varistor (MOV) whose rated operating voltage satisfies: higher than the normal operating voltage of the all-solid-state power unit and lower than its maximum withstand voltage value, and is used to absorb transient overvoltage energy.

[0053] In some embodiments, in the multi-unit series-parallel structure: the number of series branches is determined by the voltage difference when the switch is disconnected, so as to ensure that the voltage of a single all-solid-state power unit is within a safe range; the number of parallel branches is determined by the instantaneous maximum current in the ice melting state, so as to improve the system current capacity.

[0054] In a preferred embodiment, the voltage difference is calculated according to the following formula:

[0055] ;

[0056] in, is the distance between the short-circuit point on the current conductor and the short-circuit point The voltage difference at is the phase current of the carrier conductor, is the distance to the short-circuit point, is the resistance per unit length of the sub-conductor, It is the inductance of the sub-conductor when one of the sub-conductors is conducting current and the other is interrupted.

[0057] In a preferred embodiment, the RCD voltage limiting module parameters satisfy the following formula:

[0058] ;

[0059] Where C is the capacitance value, is the stray inductance in the IGBT turn-off circuit;

[0060] The value of resistance R should satisfy the following formula:

[0061] ;

[0062] in, is the maximum collector current of the IGBT.

[0063] In a preferred embodiment, the actual number of the series-parallel branches is 1.5 times the calculated number in a redundant configuration.

[0064] In some embodiments, the multi-unit series-parallel structure further includes: a buffer impedance element connected to each all-solid-state power unit, for suppressing inter-unit circulating current and oscillation.

[0065] Specific embodiments of the present invention are further described below.

[0066] A fully solid-state breaking structure for a split conductor online non-stop ice melting device comprises a multi-unit series-parallel structure consisting of a plurality of fully solid-state power units and a control drive unit.

[0067] like Figure 1 As shown, the all-solid-state power unit includes an insulated gate bipolar transistor (IGBT) and an anti-parallel diode connected with a common emitter; the common emitter insulated gate bipolar transistor has a bidirectional conduction function, and the series-parallel structure composed of this unit should have two ports, which are respectively connected to the jumper connection of the two split conductors located on the tower.

[0068] A first insulated gate bipolar transistor IGBT1 and a second insulated gate bipolar transistor IGBT2, a first diode D1 and a second diode D2; the emitter of the first insulated gate bipolar transistor IGBT1 is connected to the emitter of the second insulated gate bipolar transistor IGBT2, the cathode of the first diode D1 is connected to the collector of the first insulated gate bipolar transistor IGBT1, and the cathode of the second diode D2 is connected to the collector of the second insulated gate bipolar transistor IGBT2, forming an anti-parallel structure; the gates of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor are respectively connected to the control drive unit, for independently receiving control signals with the same timing; the anti-parallel structure can realize bidirectional current conduction and blocking functions, and is suitable for switching operations of AC circuits.

[0069] In this embodiment, the current flowing through the high-voltage transmission line and the corresponding rated sub-conductor has a significant impact on the voltage difference at the switch, thereby helping to determine the parameters and selection of the insulated gate bipolar transistor (IGBT).

[0070] Taking the case of two split conductors, the voltage difference between the conductors and the voltage difference between the two ends of the disconnected conductor are calculated when one of the two sub-conductors is disconnected and the other is open. According to Ohm's law, the voltage difference between the short-circuit point on the current-carrying sub-conductor and the position x away from the short-circuit point is calculated. Perform the calculation:

[0071]

[0072] in, is the distance between the short-circuit point on the current conductor and the short-circuit point The voltage difference at is the phase current of the carrier conductor, is the distance to the short-circuit point, is the resistance per unit length of the sub-conductor, It is the inductance of the sub-conductor when one of the sub-conductors is conducting current and the other is interrupted.

[0073] Furthermore, the grid frequency is 50Hz, and it can be determined that:

[0074]

[0075] in, .

[0076] Furthermore, high-voltage transmission lines mostly use steel-core aluminum stranded wire. The corresponding unit length resistance can be obtained according to the type of steel-core aluminum stranded wire used. With inductor Parameters; The current of the transmission line needs to be determined according to the actual situation. Taking 110kV as an example, the current level of the transmission line can be between 600-1200A; if the resistance and inductance parameters of the commonly used steel core aluminum stranded wire of the 110kV line are used, the distance to the short circuit point Take 10km to 20km for calculation, the voltage difference from the short-circuit point on the current conductor to the position x away from the short-circuit point It can reach between 3kV-10kV.

[0077] Furthermore, when calculating the voltage difference across the break of a high-voltage transmission line sub-conductor, the method is the same as the above method; for the current-carrying sub-conductor, the voltage at the short-circuit point is , the voltage at the short-circuit point x is For the disconnected sub-conductor, the voltage on one side is the same as the short-circuit point, and the voltage on the other side is the same as the voltage at the point x from the short-circuit point (because the ice melting device has a short-circuit point). Therefore, the voltage difference between the two ends of the conductor port is the same as the voltage difference between the split conductors mentioned above. The same range is 3kV-10kV, so the insulated gate bipolar transistor IGBT described in the patent should be selected to be a model that can carry larger voltage and larger current to reduce the number of devices used and reduce the mechanical and electrical complexity of the overall switch structure.

[0078] like Figure 2 As shown, an RCD voltage limiting circuit consisting of a resistor R, a capacitor C, and a diode D is connected in parallel with the corresponding insulated gate bipolar transistor; wherein the resistor R and the diode D are connected in parallel, and in the parallel structure formed, the parallel port on the cathode side of the diode D is connected to the capacitor C, that is, the parallel structure composed of the resistor R and the diode D is connected in series with the capacitor C to form a complete voltage limiting module; the resistor R is used to limit the overvoltage amplitude during the breaking process, the capacitor C is used to absorb transient energy during the breaking process and control the voltage rise rate, and the diode D is used to provide a unidirectional conduction path to ensure capacitor discharge; the impedance parameters of the voltage limiting circuit match the parasitic parameters of the insulated gate bipolar transistor to ensure uniform voltage distribution in the multi-unit structure and improve the voltage withstand capability and reliability of the system; the RCD module described in the voltage limiting circuit should be connected in parallel to both ends of each unit, and the number of RCD modules should be exactly the same as the number of anti-parallel power modules.

[0079] The parameters of the resistor R and capacitor C of the voltage limiting RCD module are selected as follows:

[0080] At the moment of turn-off, the energy in the stray inductance needs to be completely transferred to the capacitor C, which is:

[0081]

[0082] in is the stray inductance in the IGBT circuit breaker, which can be obtained from the empirical formula:

[0083]

[0084] In this embodiment, the disconnect structure is in a normally open or normally closed state, and there is no need to consider the influence of C discharging through R, so a relatively large capacitance C value can be appropriately selected; the disconnect structure described in this patent should also fully consider the heat dissipation of the online ice melting device. When a larger capacitor is discharged, the current amplitude borne by the resistor R can be smaller, reducing the power of R, thereby reducing the overall structure size and current heat generation, effectively reducing the heat dissipation pressure of the overall device; the discharge current of the capacitor C should be limited to 25% of the maximum value of the IGBT collector current Therefore, the value of the resistor R should satisfy the following formula:

[0085]

[0086] Furthermore, a metal oxide varistor (MOV) overvoltage protection device is provided, wherein the metal oxide varistor is connected in parallel at both ends of each all-solid-state power unit; the rated operating voltage of the metal oxide varistor is higher than the normal operating voltage of the all-solid-state power unit and lower than the maximum withstand voltage value of the all-solid-state power unit; when a transient overvoltage occurs in the system, the metal oxide varistor is turned on to absorb excess energy, thereby limiting the voltage amplitude at both ends of the all-solid-state power unit.

[0087] like Figure 3 As shown, the multi-unit series-parallel structure includes: multiple all-solid-state power units are connected in series to form multiple series branches, and the multiple series branches are connected in parallel to form a complete disconnect unit; the number of all-solid-state power units in each series branch is determined based on the voltage difference in the switch disconnection scenario to ensure that the voltage to be borne by each all-solid-state power unit is within a safe range; the number of parallel branches is determined based on the instantaneous maximum current that can pass through the sub-conductor in the ice-melting state to improve the current carrying capacity of the system;

[0088] Among them, considering that the on-state loss of the insulated gate bipolar transistor (IGBT) is high when the current is large, IGBTs with higher withstand voltage and higher maximum collector current should be selected as much as possible to reduce the number of series branches and thus reduce the overall heat dissipation pressure of the ice melting device.

[0089] In this embodiment, redundancy also needs to be considered in the series-parallel structure. Since the circuit-breaking structure is used in a trunk transmission line with a higher voltage level, the actual number of series-parallel branches must be 1.5 times the calculated number of series-parallel branches. The various all-solid-state power units in the multi-unit series-parallel structure are synchronously opened and closed through the control drive unit to ensure uniform distribution of voltage and current.

[0090] like Figure 4 As shown, the all-solid-state disconnect mechanism of the present invention can be applied to a four-split conductor system. In this embodiment, the all-solid-state disconnect mechanism is installed on one of the four-split conductors. When ice melting is required, the control system issues a command, and the all-solid-state disconnect mechanism executes the disconnect operation according to a pre-set program, directing the ice-melting current to the remaining designated conductor while maintaining normal power supply to the remaining conductors, thus achieving the goal of ice melting without power outage.

[0091] In this embodiment, the all-solid-state disconnect structure used in the online, non-stop de-icing device for split conductors should be placed as a disconnect module in the de-icing device. The ideal installation location for the de-icing device is at the conductor connection portion of the transmission tower. At this installation location, the control unit of the all-solid-state disconnect structure adopts a sealed and waterproof design, which can adapt to various adverse climatic conditions. The control unit maintains real-time data exchange with the ground monitoring center through a fiber-optic communication system, and can remotely monitor the operating status of the device and receive control instructions. When the meteorological monitoring system detects the risk of icing, the control center issues an de-icing instruction. The all-solid-state disconnect structure first executes the operation of disconnecting the designated sub-conductor, and then the de-icing current flows into the remaining sub-conductors. During the entire process, grid users do not perceive the power outage, achieving true "de-icing without power outage."

[0092] In summary, the present invention proposes an all-solid-state disconnecting structure for an online, non-stop de-icing device for split conductors. This structure uses an all-solid-state IGBT as the core power electronic device, constructs the circuit breaker unit through an anti-parallel topology, and utilizes a passive RCD circuit to achieve a voltage limiting function. The present invention designs a multi-unit series-parallel configuration scheme, which effectively improves the system's voltage resistance and current capacity, and adapts to the voltage and current requirements of high-voltage lines. The disconnecting structure has the advantages of fast response speed, high reliability, and good electromagnetic compatibility. It can achieve de-icing operations on high-voltage lines without interrupting power supply, solving the technical problem of traditional de-icing methods requiring power outages. The all-solid-state disconnecting structure of the present invention replaces mechanical switches, eliminating the aging of mechanical components and the hidden dangers of arcing, and avoiding potential disconnection failures of mechanical switches in extreme environments such as cold and humid conditions. At the same time, the optimized anti-parallel topology and RCD voltage limiting circuit design ensure the stable operation of the system in high-voltage environments. The solution of the present invention is of great significance for improving the operational reliability of power grids under harsh climatic conditions.

[0093] The above description further details the present invention in conjunction with specific / preferred embodiments, and the specific implementation of the present invention should not be construed as being limited to these descriptions. Persons skilled in the art will appreciate that, without departing from the spirit of the present invention, they may make various substitutions or modifications to the described embodiments, and these substitutions or modifications should be considered to fall within the scope of protection of the present invention. Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "preferred embodiments," "examples," "specific examples," or "some examples" indicates that the specific features, structures, materials, or characteristics described in conjunction with such embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Persons skilled in the art may combine and assemble the different embodiments or examples described in this specification, as well as features of different embodiments or examples, without conflicting opinions. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications may be made herein without departing from the scope of protection of the patent application.

Claims

1. A fully solid-state disconnecting structure for a split conductor online non-stop ice melting device, characterized in that: include: A series of multi-unit series-parallel structures, each multi-unit series-parallel structure being configured corresponding to a sub-conductor in the split conductor, wherein each multi-unit series-parallel structure comprises a plurality of all-solid-state power units connected in series to form a plurality of series branches, and the plurality of series branches are connected in parallel; Wherein, the all-solid-state power unit comprises: An anti-parallel topology consisting of a pair of insulated gate bipolar transistors (IGBTs) connected with a common emitter and an anti-parallel diode to achieve bidirectional current conduction and blocking; A voltage limiting circuit comprises an RCD voltage limiting module formed by a resistor (R), a capacitor (C), and a diode (D), which are connected in parallel across each insulated gate bipolar transistor. The resistor (R) and the diode (D) are connected in parallel to form a parallel structure, and the capacitor (C) is connected in series to the cathode side port of the diode in the parallel structure. The resistor is used to limit the overvoltage amplitude, the capacitor is used to absorb transient energy and control the voltage rise rate, and the diode (D) provides a capacitor discharge path. an overvoltage protection device connected in parallel across each insulated gate bipolar transistor; A control drive unit electrically connected to the gate of each insulated gate bipolar transistor, wherein each all-solid-state power unit in the multi-unit series-parallel structure is controlled by the control drive unit to achieve synchronous switching on and off; The two ports of each multi-unit series-parallel structure are respectively connected to the jumper strings of two split conductors located on the transmission tower; The all-solid-state power unit specifically includes a first insulated gate bipolar transistor (IGBT1), a second insulated gate bipolar transistor (IGBT2), a first diode (D1) and a second diode (D2); The emitters of the first insulated gate bipolar transistor (IGBT1) and the second insulated gate bipolar transistor (IGBT2) are connected in common, the cathode of the first diode (D1) is connected to the collector of the first insulated gate bipolar transistor (IGBT1), and the cathode of the second diode (D2) is connected to the collector of the second insulated gate bipolar transistor (IGBT2), forming an anti-parallel bidirectional conduction structure; The gates of the first insulated gate bipolar transistor (IGBT1) and the second insulated gate bipolar transistor (IGBT2) are independently connected to the control drive unit for independently receiving control signals with the same timing; the anti-parallel bidirectional conduction structure can realize bidirectional current conduction and blocking functions, and is suitable for switching operations of AC circuits.

2. The all-solid-state breaking structure according to claim 1, characterized in that: The overvoltage protection device is a metal oxide varistor (MOV), and its rated working voltage meets the following requirements: It is higher than the normal operating voltage of the all-solid-state power unit and lower than its maximum withstand voltage, and is used to absorb transient overvoltage energy.

3. The all-solid-state breaking structure according to claim 1, characterized in that: In the multi-unit series-parallel structure: The number of series branches is determined by the voltage difference when the switch is disconnected to ensure that the voltage of a single all-solid-state power unit is within a safe range; The number of parallel branches is determined by the instantaneous maximum current in the ice melting state to increase the system current capacity.

4. The all-solid-state breaking structure according to claim 3, characterized in that: The voltage difference is calculated according to the following formula: ； in, is the distance between the short-circuit point on the current conductor and the short-circuit point The voltage difference at is the phase current of the carrier conductor, is the distance to the short-circuit point, is the resistance per unit length of the sub-conductor, It is the inductance of the sub-conductor when one of the sub-conductors is conducting current and the other is interrupted.

5. The all-solid-state breaking structure according to claim 4, characterized in that: The RCD voltage limiting module parameters satisfy the following formula: ； Where C is the capacitance value, is the stray inductance in the IGBT turn-off circuit, The value of resistance R should satisfy the following formula: ； in, is the maximum collector current of the IGBT.

6. The all-solid-state breaking structure according to claim 3, characterized in that: The actual number of series-parallel branches of the multi-unit series-parallel structure is a redundant configuration of 1.5 times the calculated number.

7. The all-solid-state breaking structure according to any one of claims 1 to 6, characterized in that: The multi-unit series-parallel structure further includes: The buffer impedance element connected to each all-solid-state power unit is used to suppress the circulating current and oscillation between the units.

8. The all-solid-state breaking structure according to any one of claims 1 to 6, characterized in that: The control drive unit satisfies: The gate control signals output to each insulated gate bipolar transistor in the multi-unit series-parallel structure are synchronized, and the time difference is within a set acceptable error range; The gate control signals of all the insulated gate bipolar transistors on the same sub-conductor are the same.

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