Cascade direct-current deicing system of high-voltage transmission line, control method and device

Abstract

The invention relates to the technical field of ice prevention and disaster reduction of high-voltage power transmission lines, and discloses a cascaded direct-current ice melting system of a high-voltage power transmission line, a control method and a device. The method comprises the following steps: inputting a test signal to the cascaded direct-current deicing system, and detecting the voltage and current of each node; calculating line impedance distribution based on the voltage and current of each node, and constructing a line equivalent model; calculating the minimum ice melting current based on the ice thickness monitoring data and the weather data, and calculating the output current of each ice melting device based on the minimum ice melting current and the line equivalent model; monitoring circulating current between systems, and calculating virtual compensation voltage based on the circulating current; and adjusting the output voltage of each ice melting device based on the virtual compensation voltage. The ice melting success rate, the safety of the system and the service life of the system can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of anti-icing and disaster reduction technology for high-voltage transmission lines, and more specifically, to a cascaded DC de-icing system, control method, and device for high-voltage transmission lines. Background Technology

[0002] Icing on high-voltage transmission lines is one of the most serious natural disasters threatening the safe and stable operation of the power grid. Currently, the most effective countermeasure is to use de-icing devices to apply a power frequency current far exceeding the normal load to the lines, utilizing the Joule heating effect to melt the icing.

[0003] With rising voltage levels and increasing demand for de-icing, the capacity of traditional single de-icing devices is limited and cannot meet the de-icing needs of high-voltage lines. The common solution adopted in the industry is to operate multiple de-icing devices in parallel. However, parallel operation of multiple devices can lead to problems such as uneven current distribution, circulating current loss, and control response lag, which can easily cause local overheating or de-icing failure. Summary of the Invention

[0004] In view of the above situation, this application provides a cascaded DC de-icing system, control method and device for high-voltage transmission lines, which aims to solve the above problems or at least partially solve the above problems.

[0005] In a first aspect, embodiments of this application provide a cascaded DC de-icing control method for high-voltage transmission lines, applied to a cascaded DC de-icing system, wherein the cascaded DC de-icing system includes multiple de-icing devices, and the method includes:

[0006] Input a test signal into the cascaded DC ice melting system to detect the voltage and current of each node;

[0007] Based on the voltage and current at each node, the impedance distribution of the line is calculated, and an equivalent model of the line is constructed.

[0008] Based on ice thickness monitoring data and weather data, the minimum ice melting current is calculated, and the output current of each ice melting device is calculated based on the minimum ice melting current and the line equivalent model.

[0009] Monitor the circulating current between systems and calculate the virtual compensation voltage based on the circulating current;

[0010] The output voltage of each ice-melting device is adjusted based on virtual compensation voltage.

[0011] Secondly, embodiments of this application also provide a cascaded DC de-icing system for high-voltage transmission lines, comprising:

[0012] A master controller, connected to multiple slave controllers, is configured to execute the calculation and decision-making steps of the control method;

[0013] Each slave controller is connected to an ice-melting device and is used to control the output current and output voltage of the ice-melting device.

[0014] The sensors, including distributed temperature sensors, voltage sensors, and current sensors, are connected to the main controller and the icing line respectively, and are used to collect line node data in real time.

[0015] Multiple de-icing devices are used to de-ic the icy circuit based on the output current and to suppress circulating current based on the output voltage.

[0016] Thirdly, embodiments of this application also provide a cascaded DC de-icing control device for high-voltage transmission lines, characterized in that the device comprises:

[0017] The input module is used to input test signals into the cascaded DC ice melting system to detect the voltage and current of each node;

[0018] The module is used to calculate the line impedance distribution and build an equivalent line model based on the voltage and current of each node.

[0019] The calculation module is used to calculate the minimum de-icing current based on ice thickness monitoring data and weather data, and to calculate the output current of each de-icing device based on the minimum de-icing current and the line equivalent model.

[0020] The adjustment module is used to monitor the circulating current between systems, calculate the virtual compensation voltage based on the circulating current, and adjust the output voltage of each device based on the virtual compensation voltage.

[0021] Fourthly, embodiments of this application also provide an electronic device, including: a processor; and a memory arranged to store computer-executable instructions, which, when executed, cause the processor to perform the steps described in the first aspect.

[0022] Fifthly, embodiments of this application also provide a computer-readable storage medium that stores one or more programs, which, when executed by an electronic device including multiple applications, cause the electronic device to perform the steps described in the first aspect.

[0023] The above-mentioned technical solutions adopted in the embodiments of this application can achieve the following beneficial effects: This application actively senses and constructs an accurate equivalent circuit model by injecting test signals. Based on this model and the de-icing requirements, it allocates appropriate current commands to each device, ensuring that the output current of each device is highly consistent with the theoretical value, maximizing the utilization of the capacity of all devices, and ensuring stable and reliable total system output, thus guaranteeing the success rate of de-icing operations. Furthermore, by monitoring the circulating current in real time and calculating the virtual compensation voltage, the output voltage of each device is dynamically adjusted, which is equivalent to adding a "virtual resistor" in the control loop. This actively cancels the potential difference that generates the circulating current, significantly saving energy, effectively reducing the current stress of power devices (such as IGBTs), avoiding abnormal heating, and greatly improving the safety and service life of the equipment. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 A schematic diagram of the structure of the cascaded DC de-icing system for high-voltage transmission lines provided in an embodiment of this application is shown;

[0026] Figure 2 A flowchart illustrating the cascaded DC de-icing control method for high-voltage transmission lines provided in an embodiment of this application is shown.

[0027] Figure 3 A flowchart of a cascaded DC de-icing control method for high-voltage transmission lines according to another embodiment of this application is shown;

[0028] Figure 4 A flowchart of a cascaded DC de-icing control method for high-voltage transmission lines provided in another embodiment of this application is shown;

[0029] Figure 5 This paper shows a structural diagram of a cascaded DC de-icing control device for high-voltage transmission lines provided in an embodiment of this application.

[0030] Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such use can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the term "comprising" and its variations should be interpreted as open-ended terms meaning "including but not limited to."

[0033] Figure 1 This diagram illustrates the structure of a cascaded DC de-icing system for a high-voltage transmission line according to an embodiment of this application. The cascaded DC de-icing control method provided in this embodiment can be implemented through, for example... Figure 1 The system implementation, from Figure 1 As can be seen, the cascaded DC ice melting system includes a main controller, slave controllers, sensors, and multiple ice melting devices.

[0034] The master controller is connected to multiple slave controllers and is configured to execute the calculation and decision-making steps of the control method.

[0035] Each slave controller connects to one ice-melting device and controls the output current and output voltage of the ice-melting device by receiving instructions from the master controller.

[0036] The sensors are connected to the main controller and the icing line respectively, including distributed temperature sensors, voltage sensors and current sensors, for real-time acquisition of line node data;

[0037] Multiple de-icing devices (only one is shown in the figure; the specific number of de-icing devices can be set according to actual needs) are used to de-ic the icy circuit based on the output current and to suppress circulating current based on the output voltage.

[0038] It should be noted that this application is not limited to Figure 1 The page performance evaluation system shown can be any system, device, or framework that can implement the business logic of this application. Figure 1 This is merely an illustrative example.

[0039] Figure 2This paper illustrates a flowchart of a cascaded DC de-icing control method for a high-voltage transmission line according to an embodiment of this application. Figure 2 It can be seen that the method may include steps S101 to S105:

[0040] Step S101: Input a test signal into the cascaded DC ice melting system to detect the voltage and current of each node.

[0041] Step S102: Based on the voltage and current of each node, calculate the line impedance distribution and construct the line equivalent model.

[0042] Step S103: Based on ice thickness monitoring data and weather data, calculate the minimum de-icing current, and based on the minimum de-icing current and the line equivalent model, calculate the output current of each de-icing device.

[0043] Step S104: Monitor the circulating current between systems and calculate the virtual compensation voltage based on the circulating current.

[0044] Step S105: Adjust the output voltage of each ice-melting device based on the virtual compensation voltage.

[0045] In some embodiments, the output voltage is: V out =V base +ΔV C , where V out Indicates the output voltage, V base Represents the original output voltage, ΔV C This represents the virtual compensation voltage.

[0046] from Figure 1 As shown in the method, this application actively senses and constructs an accurate equivalent circuit model by injecting test signals. Based on this model and the de-icing requirements, appropriate current commands are assigned to each device, ensuring that the output current of each device closely matches the theoretical value. This maximizes the utilization of the capacity of all devices, ensuring stable and reliable total system output and guaranteeing the success rate of de-icing operations. Furthermore, by monitoring the circulating current in real time and calculating the virtual compensation voltage, the output voltage of each device is dynamically adjusted. This is equivalent to adding a "virtual resistor" to the control loop, actively offsetting the potential difference that generates the circulating current, significantly saving energy, effectively reducing the current stress on power devices (such as IGBTs), avoiding abnormal heating, and greatly improving the safety and service life of the equipment.

[0047] In some embodiments of this application, in the above method, the test signal in step S101 is a frequency sweep test signal, which uses a pseudo-random sequence:

[0048]

[0049] Among them, fk =f min ·2 (k-1) / n k = 1, 2, 3, ..., M, f min The initial frequency is represented by n, the frequency density coefficient is represented by M, the total number of frequency points is represented by k, and the phase is represented by k. It is randomly generated in the range [0, 2π].

[0050] In this embodiment, a circuit equivalent model is established by sweeping frequency test signals. Compared with the traditional fixed frequency detection method, the impedance measurement accuracy is improved, and the output weights of each ice melting device can be dynamically adjusted.

[0051] In some embodiments of this application, in the above method, step S102 calculates the line impedance distribution based on the following formula:

[0052]

[0053] Among them, Z l (x) represents the equivalent impedance at position x, I ref (x,f) is the reference current at a certain position x after the test signal is injected, V in (x,f) represents the voltage value injected at a certain position x, where x represents the position and f represents the frequency.

[0054] The equivalent model of the line is:

[0055]

[0056] Among them, R eq L represents the equivalent resistance of the line. eq Indicates the equivalent inductance of the line, N represents the number of sweep points, f k Z(f) represents the frequency of the k-th sweep signal. k ) indicates that the line is at frequency f k The complex impedance below.

[0057] In this embodiment, by accurately extracting the two key parameters of the line, the equivalent resistance and equivalent inductance, this quantitative modeling method greatly improves the accuracy and reliability of the model compared with traditional empirical estimation, laying a solid mathematical foundation for subsequent accurate current distribution and serving as a prerequisite for achieving efficient current sharing.

[0058] In some embodiments of this application, step S103 in the above method can be specifically implemented as the following steps, such as... Figure 3 As shown, steps S1031-S1034 are included:

[0059] S1031: Calculate the minimum ice-melting current based on the latent heat of ice melting, the resistivity of the conductor, the temperature coefficient of resistance of the conductor, and the temperature change of the conductor.

[0060] In some embodiments, the minimum de-icing current is calculated based on the following method:

[0061]

[0062] Among them, I min This represents the minimum de-icing current, K represents the safety factor, and h ice Indicates ice thickness monitoring data, λ ice The latent heat of fusion of ice is typically 334 kJ / kg, ρ0 represents the resistivity of the conductor at 0℃, α represents the temperature coefficient of resistance of the conductor, and ΔT represents the temperature change of the conductor.

[0063] S1032: Determine the total de-icing current required for the line based on the minimum de-icing current.

[0064] In some embodiments, the total de-icing current required for the line is greater than or equal to the minimum de-icing current, for example, the total de-icing current required for the line = k × minimum de-icing current, where k > 1.

[0065] S1033: Determine the equivalent resistance of the line based on the equivalent line model.

[0066] S1034: Calculate the output current of each de-icing device based on the total de-icing current required for the line, the equivalent resistance of the line, the line resistance corresponding to the de-icing device, and the temperature rise of the IGBT of the de-icing device.

[0067] In some embodiments, the output current of each ice-melting device is calculated based on the following method:

[0068]

[0069] Among them, I j I represents the output current of the j-th ice-melting device. t R represents the total de-icing current required for the line. j R represents the equivalent resistance of the j-th section of the line. k β represents the line resistance corresponding to the k-th device, β represents the temperature compensation coefficient, and ΔT j This indicates the temperature rise of the IGBT in the j-th ice-melting device.

[0070] In this embodiment, not only is the line impedance (inverse impedance principle) considered during allocation, but IGBT temperature rise is also introduced as a compensation factor. This ensures the de-icing effect while taking into account the device's own working status and safety, effectively preventing device damage caused by overheating.

[0071] In some embodiments of this application, in step S104 above, if the ring current is less than the preset current, the virtual compensation voltage is calculated based on the proportional coefficient and the ring current; if the ring current is greater than or equal to the preset current, the virtual compensation voltage is calculated based on the DC bus voltage, the ring current and the integral coefficient.

[0072] Specifically, the virtual compensation voltage is calculated based on the following method:

[0073]

[0074] Where, ΔV C Indicates the virtual compensation voltage, I loop Indicates inter-device circulation, I n Indicates the rated current of the device, K p K represents the proportionality coefficient. i V represents the integral coefficient. dc This indicates the DC bus voltage.

[0075] In this embodiment, when multiple ice-melting devices are cascaded, ideally, all current should flow out of the devices, through the transmission lines, and back to the devices, forming a large loop. However, no two physical devices have completely identical characteristics, resulting in a voltage difference in the output voltage. This voltage difference creates a localized, unwanted conductive loop between the parallel ports, generating a current that circulates only between the devices and does not flow through the external transmission lines. If this circulating current is not suppressed, it will increase system losses and heat generation, reduce effective output capacity, and threaten equipment safety. This application calculates a compensation voltage value in real time based on the magnitude of the circulating current, and superimposes the compensation voltage onto the original output voltage, eliminating the voltage difference that generates the circulating current at its source.

[0076] Figure 4 This paper illustrates a flowchart of a cascaded DC de-icing control method according to another embodiment of the present application. Figure 4 As can be seen, the news recommendation method in this embodiment includes the following steps S201-S203:

[0077] Step S201: In response to the detection of at least one malfunction in the de-icing device, determine the total available current of the system based on the rated maximum current of the normally operating de-icing device and the steady current at the current temperature.

[0078] Specifically, the main controller determines whether the de-icing device has malfunctioned. For example, if the main controller does not receive a response signal from a slave controller within a specified time window; or if the main controller determines whether the de-icing device has malfunctioned based on key parameters reported by the slave controller (such as excessively high IGBT temperature or abnormal DC bus voltage).

[0079] Furthermore, when a fault is detected in a certain ice-melting device, the location of the fault is determined, and the total available current of the system is determined.

[0080]

[0081] Among them, I ava I represents the total available current of the system. j,max I represents the rated maximum current of the j-th device. j，thermal This represents the steady current at the current temperature.

[0082] Step S202: If the total available current of the system is greater than or equal to the preset total current, increase the output current of the normally operating ice melting device.

[0083] In some embodiments, if I ava ≥0.7I t If the system continues to operate, the output current of the normally operating ice-melting device will be recalculated based on the total available current of the system.

[0084] Step S203: If the total available current of the system is less than the preset total current, the ice is melted in sections based on the priority of the sections.

[0085] In some embodiments, if I ava <0.7I t If so, the segmented ice melting strategy will be activated.

[0086] Specifically, the priority of a segment is calculated based on the following method:

[0087]

[0088] Among them, h ice R represents ice thickness monitoring data. se It is the section equivalent resistance, L cri It is the length of the critical section, L t It is the total length of the line.

[0089] In this embodiment, when a de-icing device malfunctions, the system does not simply shut down but quickly reconfigures, utilizing the remaining operational devices to continue working, thus maximizing the continuity of de-icing operations. Simultaneously, by calculating the total available current and comparing it with a preset threshold, the system can intelligently decide whether to operate at full capacity or perform segmented de-icing. This graceful degradation strategy ensures that core tasks can still be performed even in the event of a failure, improving the overall system reliability. Furthermore, by considering ice thickness (threat level), resistive heating effect (de-icing efficiency), and critical section length (safety importance), the system prioritizes melting the most dangerous, easily meltable, and critical line sections when system capacity is insufficient, thereby maximizing the utilization efficiency of limited resources and quickly eliminating the greatest safety threats.

[0090] In some embodiments of this application, a cascaded DC de-icing control device for high-voltage transmission lines is provided, which corresponds one-to-one with the cascaded DC de-icing control method for high-voltage transmission lines described in the above embodiments. For example... Figure 5 As shown, the cascaded DC de-icing control device for the high-voltage transmission line includes an input module 501, a construction module 502, a calculation module 503, and an adjustment module 504.

[0091] The input module 501 is used to input test signals into the cascaded DC ice melting system to detect the voltage and current of each node;

[0092] Module 502 is used to calculate the line impedance distribution and construct the equivalent line model based on the voltage and current of each node.

[0093] The calculation module 503 is used to calculate the minimum de-icing current based on ice thickness monitoring data and weather data, and to calculate the output current of each de-icing device based on the minimum de-icing current and the line equivalent model.

[0094] The adjustment module 504 is used to monitor the circulating current between systems, calculate the virtual compensation voltage based on the circulating current, and adjust the output voltage of each device based on the virtual compensation voltage.

[0095] In some embodiments of this application, the equivalent model of the line in the above-described apparatus is:

[0096]

[0097] Among them, R eq L represents the equivalent resistance of the line. eq Indicates the equivalent inductance of the line, N represents the number of sweep points, f k Z(f) represents the frequency of the k-th sweep signal. k ) indicates that the line is at frequency f k The complex impedance below.

[0098] In some embodiments of this application, the test signal uses a pseudo-random sequence:

[0099]

[0100] Among them, f k =f min ·2 (k-1) / n k = 1, 2, 3, ..., M, f min The initial frequency is represented by n, the frequency density coefficient is represented by M, the total number of frequency points is represented by k, and the phase is represented by k. It is randomly generated in the range [0, 2π].

[0101] In some embodiments of this application, the calculation module 503 is specifically used to calculate the minimum ice-melting current based on the latent heat of melting of ice, the resistivity of the conductor, the temperature coefficient of resistance of the conductor, and the temperature change of the conductor.

[0102] Determine the total de-icing current required for the line based on the minimum de-icing current;

[0103] Determine the equivalent resistance of the line based on the equivalent line model;

[0104] Based on the total de-icing current required for the line, the equivalent resistance of the line, the line resistance corresponding to the de-icing device, and the IGBT temperature rise of the de-icing device, calculate the output current of each de-icing device.

[0105] In some embodiments of this application, the calculation module 503 is specifically used to calculate the virtual compensation voltage based on the proportional coefficient and the ring current if the ring current is less than the preset current.

[0106] If the loop current is greater than or equal to the preset current, the virtual compensation voltage is calculated based on the DC bus voltage, the loop current, and the integral coefficient.

[0107] In some embodiments of this application, the calculation module 503 is further configured to determine the total available current of the system based on the rated maximum current of a normally operating ice-melting device and the stable current at the current temperature in response to the detection of a malfunction in at least one ice-melting device.

[0108] If the total available current of the system is greater than or equal to the preset total current, increase the output current of the normally operating ice-melting device;

[0109] If the total available current of the system is less than the preset total current, ice melting will be carried out in segments based on the priority of the sections.

[0110] In some embodiments of this application, the priority of the segment is calculated based on the following method:

[0111]

[0112] Among them, R se It is the section equivalent resistance, L cri It is the length of the critical section, L t It is the total length of the line.

[0113] It should be noted that the cascaded DC de-icing control device for any of the above-mentioned high-voltage transmission lines can be used to implement the aforementioned cascaded DC de-icing control method for high-voltage transmission lines, which will not be elaborated here.

[0114] Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown. Figure 6As shown, at the hardware level, this electronic device includes a processor, and optionally also includes an internal bus, a network interface, and memory. The memory may include main memory, such as high-speed random-access memory (RAM), or it may include non-volatile memory, such as at least one disk drive. Of course, this electronic device may also include other hardware required for other business operations.

[0115] The processor, network interface, and memory can be interconnected via an internal bus, which can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0116] Memory is used to store programs. Specifically, programs may include program code, which includes computer operation instructions. Memory may include main memory and non-volatile memory, and provides instructions and data to the processor.

[0117] The processor reads the corresponding computer program from non-volatile memory into main memory and then runs it, forming a cascaded DC de-icing control device for high-voltage transmission lines at the logical level. The processor executes the program stored in memory and specifically performs the aforementioned method.

[0118] The processor may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0119] This electronic device can execute the cascaded DC de-icing control method for high-voltage transmission lines provided in several embodiments of this application, and realize a cascaded DC de-icing control device for high-voltage transmission lines. Figure 5 The functions of the embodiments shown are not described in detail here.

[0120] This application also proposes a computer-readable storage medium that stores one or more programs, the programs including instructions that, when executed by an electronic device including multiple applications, enable the electronic device to perform the cascaded DC de-icing control method for high-voltage transmission lines provided in several embodiments of this application.

[0121] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0122] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0123] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0124] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0125] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0126] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0127] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0128] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0129] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0130] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A cascaded DC de-icing control method for a high voltage transmission line, characterized in that, The method is applied to a cascade DC de-icing system including a plurality of de-icing devices, and comprises the following steps: inputting a test signal to the cascade DC de-icing system, detecting the voltage and current of each node; calculating the line impedance distribution based on the voltage and current of each node, and constructing a line equivalent model; calculating the minimum de-icing current based on the ice thickness monitoring data and weather data, and calculating the output current of each de-icing device based on the minimum de-icing current and the line equivalent model; monitoring the circulating current between systems, and calculating a virtual compensation voltage based on the circulating current; adjusting the output voltage of each de-icing device based on the virtual compensation voltage.

2. The method of claim 1, wherein, The line equivalent model is: where R eq represents the line equivalent resistance, L eq represents the line equivalent inductance, N represents the number of sweep points, f k represents the frequency of the kth sweep signal, Z(f k ) represents the complex impedance of the line at the frequency f k .

3. The method of claim 1, wherein, The test signal adopts a pseudo-random sequence: where f k = f min · 2 (k-1) / n , k = 1, 2, 3, …, M, f min represents the starting frequency, n represents the frequency point density coefficient, M represents the total number of frequency points, k represents the frequency point sequence number, and the phase is randomly generated in [0, 2π].

4. The method of claim 1, wherein, The calculation of the minimum de-icing current based on the ice thickness monitoring data and weather data, and the calculation of the output current of each de-icing device based on the minimum de-icing current and the line equivalent model, comprises: calculating the minimum de-icing current based on the latent heat of ice melting, the resistivity of the conductor, the temperature coefficient of the conductor resistance, and the temperature variation of the conductor; determining the total de-icing current required by the line based on the minimum de-icing current; determining the line equivalent resistance based on the line equivalent model; calculating the output current of each de-icing device based on the total de-icing current required by the line, the line equivalent resistance, the line resistance corresponding to the de-icing device, and the IGBT temperature rise of the de-icing device.

5. The method of claim 1, wherein, The calculation of the virtual compensation voltage based on the circulating current comprises: if the circulating current is less than a preset current, calculating the virtual compensation voltage based on a proportional coefficient and the circulating current; if the circulating current is greater than or equal to the preset current, calculating the virtual compensation voltage based on the DC bus voltage, the circulating current, and an integral coefficient.

6. The method according to any one of claims 1 to 5, characterized in that, The method further comprises: in response to detecting that at least one de-icing device fails, determining the total available current of the system based on the rated maximum current of the de-icing devices in normal operation and the stable current at the current temperature; if the total available current of the system is greater than or equal to a preset total current, increasing the output current of the de-icing devices in normal operation; if the total available current of the system is less than the preset total current, performing sectional de-icing based on the priority of the sections.

7. The method of claim 6, wherein, The priority of the sections is calculated based on the following manner: where R se is the segment equivalent resistance, L cri is the critical segment length, L t is the total length of the line.

8. A cascaded DC de-icing system implementing the method of any one of claims 1 to 7, characterized in that, including: a master controller connected with a plurality of slave controllers, configured to perform the calculation and decision steps of the control method; a slave controller, each slave controller being connected with one de-icing device, for controlling the output current and output voltage of the de-icing device; a sensor connected with the master controller and the icing line, including a distributed temperature sensor, a voltage sensor, and a current sensor, for collecting line node data in real time; a plurality of de-icing devices for de-icing the icing line based on the output current, and for circulating current suppression based on the output voltage.

9. A cascaded DC de-icing control device for a high voltage transmission line, characterized in that The device comprises: an input module for inputting a test signal to the cascade DC de-icing system, and detecting the voltage and current of each node; a construction module for calculating the line impedance distribution based on the voltage and current of each node, and constructing a line equivalent model; a calculation module for calculating the minimum de-icing current based on the ice thickness monitoring data and weather data, and calculating the output current of each de-icing device based on the minimum de-icing current and the line equivalent model; An adjusting module is used for monitoring the circulating current between systems, calculating a virtual compensation voltage based on the circulating current, and adjusting the output voltage of each device based on the virtual compensation voltage.

10. An electronic device comprising: a processor; and a memory arranged to store computer executable instructions which, when executed, cause the processor to perform the steps of the cascaded DC de-icing control method of a high voltage transmission line as claimed in any of claims 1-7.

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