Converter valve failure rate evaluation method, storage medium and direct current transmission system

Abstract

The application provides a converter valve failure rate evaluation method, a storage medium and a direct current power transmission system. In one working voltage period of an IGCT device of a converter valve, working voltages of the IGCT device in multiple preset time intervals are obtained, and multiple working voltages are obtained. The instantaneous failure rate of the IGCT device corresponding to each working voltage is determined according to a failure rate and voltage relationship. The failure rate and voltage relationship represents the corresponding relationship between the instantaneous failure rate of the IGCT device and its working voltage. The failure rate and voltage relationship is constructed based on an environmental parameter. The average failure rate of the IGCT device in the working voltage period is determined based on the instantaneous failure rate and the working voltage period. The failure rate of the converter valve is determined based on the average failure rate and valve group configuration parameters of the converter valve. The valve group configuration parameters include the number of single valves of the converter valve, and the series number of the IGCT devices in each single valve. The problem of low accuracy of the converter valve failure rate evaluation is solved.

Description

Technical Field

[0001] This application relates to the field of DC power transmission technology, and more specifically, to a method for evaluating the failure rate of a converter valve, a computer-readable storage medium, and a DC power transmission system. Background Technology

[0002] Inverse-resistance integrated gate commutated thyristors (IGCTs), as an emerging power semiconductor device, combine the high capacity and low loss characteristics of thyristors with the active turn-off capability of IGBTs, providing a more reliable option for high-voltage direct current transmission. In high-altitude regions, the increased intensity of cosmic rays leads to a corresponding increase in the failure rate of IGCT devices, resulting in a higher failure rate of the converter valves. This becomes a key factor limiting their application in specific geographical environments.

[0003] In terms of converter valve failure rate assessment, existing technologies only consider the failure rate at a single voltage point, which makes it difficult to accurately reflect its performance under complex operating conditions, resulting in low accuracy in converter valve failure rate assessment. Summary of the Invention

[0004] The main objective of this application is to provide a method for evaluating the failure rate of converter valves, a computer-readable storage medium, and a DC transmission system, so as to at least solve the problem of low accuracy in evaluating the failure rate of converter valves in the prior art.

[0005] To achieve the above objectives, according to one aspect of this application, a method for evaluating the failure rate of a converter valve is provided, comprising: acquiring the operating voltage of the IGCT device within a plurality of preset time intervals during one operating voltage cycle of the IGCT device of the converter valve, thereby obtaining a plurality of operating voltages, wherein the plurality of preset time intervals do not overlap; determining the instantaneous failure rate of the IGCT device corresponding to each operating voltage based on the failure rate-voltage relationship, wherein the failure rate-voltage relationship characterizes the correspondence between the instantaneous failure rate of the IGCT device and its operating voltage, wherein the failure rate-voltage relationship is constructed based on environmental parameters, including temperature and altitude; determining the average failure rate of the IGCT device within the operating voltage cycle based on the instantaneous failure rate and the operating voltage cycle; and determining the failure rate of the converter valve based on the average failure rate and valve group configuration parameters of the converter valve, wherein the valve group configuration parameters include the number of individual valves of the converter valve and the number of cascaded stages of the IGCT devices in each individual valve.

[0006] Optionally, determining the average failure rate of the IGCT device within the operating voltage cycle based on the instantaneous failure rate and the operating voltage cycle includes: obtaining the start time and end time of the operating voltage cycle; integrating the instantaneous failure rate to obtain the integrated instantaneous failure rate; and determining the average failure rate of the IGCT device within the operating voltage cycle based on the integrated instantaneous failure rate, the start time and the end time of the operating voltage cycle.

[0007] Optionally, determining the average failure rate of the IGCT device within the operating voltage cycle based on the integrated instantaneous failure rate, the start time of the operating voltage cycle, and the end time of the operating voltage cycle includes: calculating the difference between the end time of the operating voltage cycle and the start time of the operating voltage cycle to obtain the total time length of the operating voltage cycle; and calculating the ratio of the integrated instantaneous failure rate to the total time length of the operating voltage cycle to obtain the average failure rate.

[0008] Optionally, the failure rate of the converter valve is determined based on the average failure rate and the valve group configuration parameters of the converter valve. The valve group configuration parameters include the number of individual valves of the converter valve and the number of cascade stages of IGCT devices in each individual valve. This includes: calculating the product of the number of individual valves of the converter valve and the number of cascade stages of IGCT devices in each individual valve to obtain a product value; and calculating the product of the average failure rate and the product value to obtain the failure rate of the converter valve.

[0009] Optionally, before determining the instantaneous failure rate of the IGCT device corresponding to each of the operating voltages based on the failure rate-voltage relationship, the method further includes: obtaining the failure rate of the IGCT device corresponding to different operating voltages under different environmental parameters; and determining the failure rate-voltage relationship under different environmental parameters based on the failure rate corresponding to different operating voltages under different environmental parameters.

[0010] Optionally, obtaining the failure rate of the IGCT device corresponding to different operating voltages under different environmental parameters includes: for each temperature point within a preset temperature range, obtaining the failure rate of the IGCT device corresponding to different operating voltages at different altitudes, and obtaining multiple first failure rate groups at each temperature point, wherein each first failure rate group corresponds to an altitude, and the first failure rate group includes multiple failure rates corresponding to the operating voltages.

[0011] Optionally, determining the failure rate and voltage relationship under different environmental parameters based on the failure rate corresponding to different operating voltages under different environmental parameters includes: determining the failure rate and voltage relationship at different altitudes based on N sets of first failure rates at each temperature point, obtaining (N×M) sets of first failure rate and voltage relationships, where N is the number of different altitudes at each temperature point and M is the number of temperature points; and determining the failure rate and voltage relationship under different environmental parameters based on the (N×M) sets of first failure rate and voltage relationships.

[0012] Optionally, within one operating voltage cycle of the IGCT device of the converter valve, the operating voltage of the IGCT device within each preset time interval is acquired to obtain multiple operating voltages, wherein the multiple preset time intervals do not overlap. This includes: monitoring the operating voltage of the IGCT device and acquiring the operating voltage of the IGCT device at the midpoint of each preset time interval within the operating voltage cycle to obtain multiple operating voltages; determining the instantaneous failure rate of the IGCT device corresponding to each operating voltage based on the failure rate and voltage relationship, including: determining the failure rate corresponding to each operating voltage in the failure rate and voltage relationship to obtain the instantaneous failure rate of the IGCT device corresponding to each operating voltage.

[0013] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the aforementioned converter valve failure rate assessment methods.

[0014] According to another aspect of this application, a DC transmission system is provided, including a sending end, a receiving end, and a controller. The sending end includes a sending-end converter valve, which includes multiple converter valve assemblies, each of which includes an IGCT device; the receiving end includes a receiving-end converter valve, which includes multiple converter valve assemblies, each of which includes an IGCT device; the controller is connected to both the sending-end and receiving-end converter valves, and is used to execute any of the converter valve failure rate assessment methods described above.

[0015] Applying the technical solution of this application, within one operating voltage cycle of the IGCT device of the converter valve, the operating voltage of the IGCT device within each preset time interval of multiple preset time intervals is obtained, resulting in multiple operating voltages, and the multiple preset time intervals do not overlap; the instantaneous failure rate of the IGCT device corresponding to each operating voltage is determined based on the failure rate and voltage relationship, which characterizes the correspondence between the instantaneous failure rate of the IGCT device and its operating voltage, wherein the failure rate and voltage relationship is constructed based on environmental parameters, including temperature and altitude; based on the instantaneous failure rate and the operating voltage cycle, the average failure rate of the IGCT device within the operating voltage cycle is determined; based on the average failure rate and the valve group configuration parameters of the converter valve, the failure rate of the converter valve is determined, including the number of individual valves of the converter valve and the number of cascade stages of the IGCT devices in each individual valve. In this scheme, the operating voltage of the IGCT device is obtained within multiple preset time intervals during its operating voltage cycle. Combined with the influence of environmental parameters, the instantaneous failure rate within each time interval is calculated using the relationship between failure rate and voltage. Based on the instantaneous failure rate and the operating voltage cycle, the average failure rate of the IGCT device within that cycle is calculated. Then, by combining the valve group configuration parameters of the converter valve, the failure rate of the entire converter valve is determined. This overcomes the limitation of evaluating failure rate under a single voltage and solves the problem of low accuracy in evaluating converter valve failure rate in the prior art. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 A schematic flowchart of a method for evaluating the failure rate of a converter valve according to an embodiment of this application is shown.

[0018] Figure 2 The diagram shows the failure rate versus voltage curves of an IGCT device provided according to an embodiment of this application at different altitudes at 25°C.

[0019] Figure 3 A typical operating voltage waveform of an IGCT converter valve according to an embodiment of this application is shown;

[0020] Figure 4 A flowchart illustrating a reliability assessment process for an IGCT converter valve according to an embodiment of this application is shown.

[0021] Figure 5 A schematic diagram of the sending end of a DC transmission system according to an embodiment of this application is shown.

[0022] The above figures include the following reference numerals:

[0023] 01. Feeding end; 10. Feeding end converter valve; 101. Converter valve assembly; 1011. IGCT device; 02. Controller. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0026] 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 data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] As described in the background section, the failure rate assessment of converter valves in the prior art only considers the failure rate at a single voltage point, which makes it difficult to accurately reflect their performance under complex operating conditions, resulting in low accuracy of converter valve failure rate assessment. To solve the problem of low accuracy of converter valve failure rate assessment in the prior art, embodiments of this application provide a converter valve failure rate assessment method, a computer-readable storage medium, and a DC transmission system.

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] This embodiment provides a method for evaluating the failure rate of a converter valve that runs on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0030] Figure 1 This is a flowchart of a method for evaluating the failure rate of a converter valve according to an embodiment of this application. Figure 1 As shown, the method includes the following steps:

[0031] Step S101: Within one operating voltage cycle of the IGCT device of the converter valve, the operating voltage of the IGCT device within each of the preset time intervals of multiple preset time intervals is obtained, and multiple operating voltages are obtained, wherein the multiple preset time intervals do not overlap.

[0032] Specifically, the voltage that the IGCT device in the converter valve withstands during operation is not constant, but changes periodically depending on the operating state and control strategy of the power system. In order to accurately assess the failure rate of the IGCT device under actual operating conditions, it is necessary to continuously monitor and record its operating voltage within the operating voltage cycle.

[0033] Within the operating voltage cycle, several preset time intervals are set. In high-voltage direct current transmission systems, IGCT devices respond very quickly, and their operating state may change within a very short time. Therefore, the preset time intervals can be set to small values. This allows for capturing the details of rapid voltage changes in the IGCT device, especially the instantaneous state near peaks and troughs, which is crucial for evaluating its failure rate under complex operating conditions. Furthermore, smaller preset time intervals ensure that even very subtle voltage fluctuations are recorded. This is particularly critical for high-frequency, high-rate-of-change voltage signals, ensuring the accuracy of subsequent instantaneous failure rate calculations. All preset time intervals are non-overlapping, meaning they do not overlap in time; each time interval is independent. For example, if the preset time interval is 0.5 μs, voltage data will be collected every 0.5 μs starting from a certain moment until the end of a complete operating voltage cycle, ensuring that each data point represents a voltage value within an independent time segment.

[0034] This step of obtaining the operating voltage ensures that the converter valve failure rate assessment process is based on actual operating conditions rather than assumed ideal conditions, thus making the assessment results closer to reality. This provides solid data support for improving the operational safety and reliability of HVDC transmission systems and avoids assessment bias caused by using static voltage values.

[0035] Step S102: Determine the instantaneous failure rate of the IGCT device corresponding to each of the above operating voltages based on the failure rate and voltage relationship. The failure rate and voltage relationship characterizes the correspondence between the instantaneous failure rate of the IGCT device and its operating voltage. The failure rate and voltage relationship model is constructed based on environmental parameters, including temperature and altitude.

[0036] Specifically, the pre-built failure rate versus voltage relationship takes into account the impact of environmental parameters (such as temperature and altitude) on the failure rate of IGCT devices. This is because the failure rate of IGCT devices is not only related to the operating voltage but is also significantly affected by external environmental conditions such as temperature and altitude. For example, the thin atmosphere at high altitudes may lead to increased cosmic ray radiation on the device, thus affecting its failure rate; temperature changes may affect the thermal stability of the device, leading to changes in the failure rate. Based on the multiple operating voltages obtained in step S101, the instantaneous failure rate of the IGCT device within each preset time interval is calculated. The instantaneous failure rate refers to the failure rate of the IGCT device within a short period of time under specific voltage and environmental conditions. Because the voltage changes rapidly, the failure rate may be different at each instant. Determining the instantaneous failure rate through the failure rate versus voltage relationship can more accurately reflect the impact of voltage fluctuations on the failure rate of IGCT devices.

[0037] Step S102 helps to more accurately assess the failure rate of IGCT devices under actual voltage variations and environmental conditions. Compared to using failure rates under a single static voltage and environmental condition, the assessment results are closer to reality. Since the failure rate versus voltage relationship takes into account temperature and altitude, it can be applied under a wide range of operating conditions, especially in high-altitude and extreme temperature environments. This helps to optimize the design and operating strategies of IGCT converter valves. In summary, by applying the pre-built failure rate versus voltage relationship, the instantaneous failure rate of IGCT devices at each operating voltage within the operating voltage cycle can be determined more accurately, taking into account the influence of environmental parameters. This provides the necessary data foundation and technical support for the reliability assessment of converter valves.

[0038] Step S103: Based on the instantaneous failure rate and the operating voltage period, determine the average failure rate of the IGCT device within the operating voltage period.

[0039] Specifically, during the operating voltage cycle, the instantaneous failure rate varies because the voltage experienced by the IGCT device is not constant. To better reflect the failure rate of the IGCT device throughout the entire operating voltage cycle, it is necessary to calculate the average failure rate over this period. Based on the instantaneous failure rate obtained in step S102 and the entire operating voltage cycle, the average failure rate of the IGCT device over a complete operating voltage cycle is calculated through integration and averaging. This is to comprehensively consider the cumulative failure rate of the IGCT device affected by voltage variations throughout the entire operating voltage cycle, thereby improving the comprehensiveness and reliability of the evaluation.

[0040] The calculation of the average failure rate fully considers the voltage variation within the cycle and the dynamic impact of this variation on the failure rate of the IGCT device. Compared to failure rate estimation based solely on static voltage, it provides a more comprehensive risk assessment. The average failure rate is a comprehensive indicator reflecting the average probability of IGCT device failure per unit time under typical voltage variations and environmental conditions, and is crucial for evaluating the overall operational reliability of the converter valve. In short, determining the average failure rate of the IGCT device based on the instantaneous failure rate and the operating voltage cycle can comprehensively reflect the failure characteristics of the IGCT device under dynamic voltage environments.

[0041] Step S104: Determine the failure rate of the converter valve based on the average failure rate and the valve group configuration parameters of the converter valve. The valve group configuration parameters include the number of individual valves of the converter valve and the number of cascade stages of IGCT devices in each individual valve.

[0042] Specifically, using the average failure rate obtained in step S103, combined with the valve group configuration parameters of the converter valve (the number of individual valves in the converter valve and the number of IGCT devices in series in each individual valve), the failure rate of the entire converter valve is determined. This step allows for the assessment of the overall operational risk of the converter valve under a given configuration. The valve group configuration parameters of the converter valve include the number of individual valves and the number of IGCT devices in series in each individual valve. These valve group configuration parameters determine the structural complexity and operational reliability of the converter valve. A converter valve consists of multiple individual valves, each responsible for a portion of voltage blocking and switching. The number of individual valves affects the overall electrical and thermal management design of the converter valve. In each individual valve, there are multiple layers of IGCT devices connected in series, with each layer including one or more IGCT devices. For example, if the number of IGCT devices in series in each individual valve is m, it means that there are m layers of IGCT devices connected in series in this individual valve, with each layer including one or more IGCT devices.

[0043] To extrapolate the failure rate of the entire converter valve from the failure rate of a single IGCT device, the valve group configuration parameters of the converter valve need to be considered. First, considering the average failure rate of a single IGCT device and the number of IGCT devices in series within a single valve, the failure rate of a single valve can be calculated. Since the failure of IGCT devices is usually assumed to be an independent event, the failure rate of a single valve can be approximated by the linear superposition of the failure rates of individual IGCT devices. Based on the number of individual valves in the converter valve, the failure rates of the individual valves are superimposed to calculate the overall failure rate of the converter valve.

[0044] Step S104 combines the failure rate assessment at the IGCT device level with the configuration parameters at the entire converter valve level, ensuring an accurate assessment of the overall operational risk of the converter valve. Calculating the converter valve failure rate guides the design and optimization process, such as device selection, redundancy design, and adjustments to thermal management strategies, to reduce the overall system failure probability and improve the reliability and lifespan of power electronic equipment. The assessment results can also be used to optimize operational strategies, such as dynamic voltage regulation, load sharing, and fault isolation strategies, to address reliability challenges under complex environmental conditions such as high altitudes and extreme temperatures. In summary, determining the converter valve failure rate based on the average failure rate of the IGCT devices and the valve group configuration parameters is a strategy that applies device-level failure rate assessment results to system-level reliability analysis, contributing to the safe design and stable operation of high-voltage direct current transmission systems.

[0045] In this embodiment, the operating voltage of the IGCT device is acquired within multiple preset time intervals during its operating voltage cycle. By combining the influence of environmental parameters such as temperature and altitude, the instantaneous failure rate within each time interval is calculated using the relationship between failure rate and voltage. Based on the instantaneous failure rate and the operating voltage cycle, the average failure rate of the IGCT device within that cycle is calculated. Then, by combining the valve group configuration parameters of the converter valve, the failure rate of the entire converter valve is determined. This overcomes the limitation of evaluating failure rate under a single voltage, thereby solving the problem of low accuracy in evaluating converter valve failure rate in the prior art.

[0046] In the specific implementation process, based on the aforementioned instantaneous failure rate and the aforementioned operating voltage period, the average failure rate of the IGCT device within the aforementioned operating voltage period is determined, including: obtaining the start time and the end time of the aforementioned operating voltage period; integrating the aforementioned instantaneous failure rate to obtain the integrated instantaneous failure rate; and determining the aforementioned average failure rate of the IGCT device within the aforementioned operating voltage period based on the integrated instantaneous failure rate, the start time and the end time of the aforementioned operating voltage period.

[0047] The above content further details how to determine the average failure rate of an IGCT device within a given cycle based on the instantaneous failure rate and the operating voltage cycle. Specifically, the operating voltage cycle refers to a complete time-varying process of the voltage experienced by the IGCT device, from a certain starting point of voltage change to the end of a complete cycle. Obtaining the start and end times of this cycle is to determine the integration time range, i.e., the time period considered when calculating the average failure rate. This step ensures that the calculation of the average failure rate covers the entire operating voltage cycle.

[0048] The transient failure rate is the failure rate of an IGCT device at a specific point in time and under specific environmental conditions, and it varies over time. Integration is used to calculate the cumulative effect of the transient failure rate over the operating voltage cycle. Specifically, integration multiplies the transient failure rate by its corresponding time length (i.e., the small time interval between voltage changes), and then sums these multiplications. Essentially, integration calculates the area under the transient failure rate curve on the time axis, reflecting the total failure risk of the IGCT device within that cycle.

[0049] After obtaining the instantaneous failure rate after integration, the next step is to calculate the average failure rate of the IGCT device over the operating voltage cycle. This step is achieved by dividing the integral value by the total duration of the operating voltage cycle, i.e., the duration from the start to the end of the operating voltage cycle obtained in the previous step.

[0050] Further, based on the integrated instantaneous failure rate, the start time of the operating voltage cycle, and the end time of the operating voltage cycle, the average failure rate of the IGCT device within the operating voltage cycle is determined, including: calculating the difference between the end time and the start time of the operating voltage cycle to obtain the total duration of the operating voltage cycle; and calculating the ratio of the integrated instantaneous failure rate to the total duration of the operating voltage cycle to obtain the average failure rate. Specifically, the formula is used. Calculate the average failure rate, where, The average failure rate. For transient failure rate, This marks the start of the operating voltage cycle. This is the end time of the working voltage cycle.

[0051] Calculating the average failure rate of IGCT devices over the operating voltage cycle provides a more accurate reflection of their failure characteristics under dynamic voltage conditions. Compared to failure rates based solely on static voltage, this method more closely reflects actual operating conditions. The average failure rate, based on voltage variations under actual operating conditions and the instantaneous failure rate of the IGCT device, provides more accurate data support for reliability assessment. In summary, by integrating the instantaneous failure rate and combining it with the total duration of the operating voltage cycle to calculate the average failure rate, an effective means of quantitatively assessing the failure characteristics of IGCT devices under dynamic voltage conditions is provided.

[0052] In some embodiments of this application, determining the failure rate of the converter valve based on the average failure rate and the valve group configuration parameters of the converter valve includes: calculating the product of the number of individual valves of the converter valve and the number of cascade stages of IGCT devices in each individual valve to obtain a product value; and calculating the product of the average failure rate and the product value to obtain the failure rate of the converter valve.

[0053] The above explains how to determine the failure rate of a converter valve based on the average failure rate and the valve assembly configuration parameters. This process quantifies and evaluates the reliability of the entire converter valve system through calculations. Specifically, in a converter valve system, a single valve refers to the smallest independent operating unit consisting of a set of IGCT devices and other related circuits. Typically, a converter valve consists of multiple such single valves to achieve the voltage blocking and current carrying capabilities required for high-voltage direct current transmission. Within each single valve, IGCT devices are usually connected in series to improve the voltage withstand capability of the single valve. The number of series stages refers to the number of IGCT devices connected in series within a single valve. Multiplying the total number of single valves in the converter valve by the number of series stages of IGCT devices within each single valve yields the total number of IGCT devices in the entire converter valve. This calculation result reflects the configuration scale of the IGCT devices within the converter valve and is a key parameter for evaluating the overall failure rate of the converter valve. After obtaining the above product value, the next step is to multiply the above product value by the average failure rate to calculate the overall failure rate of the converter valve. The average failure rate represents the average failure risk over the operating voltage cycle, while the product value mentioned above takes into account the total number of IGCT devices in the converter valve. The failure rate of the converter valve characterizes the total failure probability of all IGCT devices in the converter valve, reflecting the overall failure risk of the entire converter valve during operation, and is a key indicator for evaluating the reliability of the converter valve. The failure rate of the converter valve is calculated using the formula... Calculations are performed, in which, The failure rate of the converter valve. The number of individual valves in the converter valve system. The number of IGCT devices in series in each individual valve. This represents the average failure rate.

[0054] The above steps quantify the total failure rate of converter valves under specific operating conditions, which helps in assessing system-level risks and providing more accurate reliability predictions. The failure rate assessment results can guide the design and optimization process of converter valves. For example, by adjusting the number of IGCT devices in series or increasing the number of individual valves, the structure of the converter valve can be optimized to reduce the total failure rate and improve system reliability. Based on the failure rate of converter valves, operating strategies can be more scientific and rational. For example, based on the failure rate assessment, optimized control strategies, such as dynamic voltage regulation, can be developed to reduce device stress and extend the life of converter valves. In the design and operation of high-voltage direct current transmission systems, the failure rate of converter valves directly affects the stability and availability of the system. By accurately calculating the failure rate of converter valves, the potential risks of the system under various operating conditions can be better understood, allowing for appropriate preventative measures to be taken, such as increasing equipment redundancy, enhancing thermal management, or optimizing control logic, to ensure the efficient and safe operation of the power system.

[0055] In some other embodiments of this application, before determining the instantaneous failure rate of the IGCT device corresponding to each of the above-mentioned operating voltages based on the failure rate-voltage relationship model, the method further includes: obtaining the failure rate of the IGCT device corresponding to different operating voltages under different environmental parameters; and determining the failure rate-voltage relationship under different environmental parameters based on the failure rate corresponding to different operating voltages under different environmental parameters.

[0056] The above describes the process of establishing the relationship between failure rate and voltage before determining the instantaneous failure rate of the IGCT device.

[0057] Furthermore, obtaining the failure rate of the IGCT device under different operating conditions under different environmental parameters includes: for each temperature point within a preset temperature range, obtaining the failure rate of the IGCT device at different operating voltages at different altitudes, and obtaining multiple first failure rate groups at each temperature point, wherein each first failure rate group corresponds to an altitude, and each first failure rate group includes multiple failure rates corresponding to operating voltages.

[0058] Specifically, a series of temperature points are selected within a preset temperature range. At each temperature point, the failure rate of the IGCT device at different operating voltages at different altitudes is measured. This effectively creates a dataset where each element represents the device's failure rate under specific environmental conditions. For each temperature point, a set of failure rate data varying with altitude is obtained, resulting in multiple first failure rate groups. These first failure rate groups describe the impact of altitude on device failure rate at specific temperatures. The preset temperature range is chosen based on the actual operating temperature range of the IGCT device and the extreme temperature conditions it may encounter. This ensures that the data coverage is sufficiently broad to reflect all temperature variations the IGCT device may experience in its actual operating environment. In this embodiment, the preset temperature range can be set to 0°C to 90°C. All the first failure rates obtained at different temperature points constitute the failure rates of the IGCT device at different operating voltages under different environmental parameters, providing rich data support for constructing the subsequent relationship between failure rate and voltage, and helping to more accurately predict the behavior of the IGCT device in its actual operating environment. In this embodiment, the altitude range can be set to 0m to 6000m, broadly covering various altitude levels at which the IGCT device can operate.

[0059] By acquiring the failure rate of IGCT devices under various operating voltage conditions at different altitudes for each temperature point within a preset temperature range, multiple first failure rate groups can be constructed. These first failure rate groups not only cover a wide range of environmental parameters but also accurately reflect the impact of altitude changes on IGCT device performance, laying a solid foundation for subsequently constructing the relationship between failure rate and voltage, and helping to improve the accuracy and reliability of IGCT device failure rate assessment.

[0060] Furthermore, the relationship between failure rate and voltage under different environmental parameters is determined based on the failure rate corresponding to different operating voltages under different environmental parameters, including: determining the relationship between failure rate and voltage at different altitudes based on N sets of first failure rates at each temperature point, resulting in (N×M) sets of first failure rate and voltage relationships, where N is the number of different altitudes at each temperature point and M is the number of temperature points; and determining the relationship between failure rate and voltage under different environmental parameters based on the (N×M) sets of first failure rate and voltage relationships.

[0061] Specifically, for N sets of first failure rate data at each temperature point (i.e., failure rates at different altitudes and operating voltages), a quantitative relationship between each set of data and the operating voltage is determined, i.e., the first failure rate versus voltage relationship is constructed. This means that for each temperature point, N failure rate versus voltage relationships at different altitudes will be established, resulting in (N×M) first failure rate versus voltage relationships. These relationships describe how the failure rate of the IGCT device changes with voltage at that temperature point. This construction process can be ensured to be accurate and applicable by applying statistical analysis, mathematical modeling, or other data analysis techniques. The first failure rate versus voltage relationships established at all temperature points are further integrated to determine the failure rate versus voltage relationships under different environmental parameters. The purpose of this comprehensive analysis is to establish a unified relationship that can predict the failure rate of IGCT devices under various environmental parameters (such as different temperatures and altitudes) as a function of voltage. This relationship can provide guidance for failure rate assessment of IGCT devices operating under different geographical and climatic conditions.

[0062] By measuring and analyzing the first failure rate of IGCT devices at different altitudes and operating voltages for each temperature point within a preset temperature range, a one-to-one relationship between the first failure rate and voltage was constructed. This relationship not only reveals the impact of temperature on IGCT device performance but also quantifies the influence of altitude-induced differences in environmental pressure and heat dissipation conditions on the IGCT device's failure rate and voltage relationship. By integrating the first failure rate and voltage relationships at all temperature points, a comprehensive failure rate and voltage relationship covering various environmental parameters was formed. This allows for accurate prediction of IGCT device behavior under a wide range of environmental conditions, providing strong data support for the optimized design, operation control, and maintenance of hybrid DC transmission systems. Particularly in applications involving high-altitude regions, it enhances adaptability to environmental changes and operational reliability.

[0063] In a specific embodiment, for each temperature point within a preset temperature range, the failure rate corresponding to different operating voltages of the IGCT device at different altitudes is obtained, resulting in multiple sets of first failure rates at each temperature point. These multiple sets of first failure rates at each temperature point can be fitted to obtain voltage-failure rate relationship curves for the IGCT device at different altitudes at each temperature. In other words, for each temperature point, there are multiple voltage-failure rate relationship curves, each corresponding to a specific altitude. Based on the obtained voltage-failure rate relationship curves, a suitable mathematical model (such as an exponential function model) is used to describe the voltage-failure rate relationship of the IGCT device at different altitudes. Each voltage-failure rate relationship curve characterizes the voltage-failure rate relationship at a specific altitude, and each temperature point corresponds to a set of first failure rate-voltage relationships. By integrating the multiple voltage-failure rate relationship curves at each temperature point, all voltage-failure rate relationship curves at all temperature points can be obtained. All voltage-failure rate relationship curves can characterize the failure rate-voltage relationship of the IGCT device under different environmental parameters. Specifically, to analyze the variation of parameters (such as those in an exponential model) in multiple voltage-failure rate relationships at various temperature points with temperature and altitude, multiple linear regression or higher-order polynomial regression can be used to express the dependence of parameters on temperature and altitude, integrating the effects of temperature and altitude into a comprehensive model. In this embodiment, an exponential function model is used as the basis, and the constructed comprehensive relationship (failure rate versus voltage relationship) is as follows: ,in, The instantaneous failure rate of the IGCT device. denoted as the operating voltage of the IGCT device, and a and b as fitting constants.

[0064] By obtaining the failure rates of IGCT devices at different operating voltages under various environmental parameters, and determining the relationship between failure rate and voltage under different environmental parameters, this study not only considers the influence of a single environmental parameter but also aims to establish the relationship between failure rate and voltage under multiple environmental factors. This makes the subsequent determination of instantaneous failure rate more accurate and can fully reflect the performance changes of IGCT devices under actual operating conditions. The relationship between failure rate and voltage under different environmental parameters has stronger generalization ability and predictive accuracy, making it suitable for evaluating the reliability of IGCT devices in complex and variable operating environments. This provides a solid foundation for the reliability assessment and optimization design of converter valves in high-voltage direct current transmission systems.

[0065] In other embodiments of this application, within one operating voltage cycle of the IGCT device of the converter valve, the operating voltage of the IGCT device within each of the preset time intervals of a plurality of preset time intervals is obtained to obtain a plurality of operating voltages, wherein the plurality of preset time intervals do not overlap, including: monitoring the operating voltage of the IGCT device and obtaining the operating voltage of the IGCT device at the midpoint of each of the preset time intervals within the operating voltage cycle to obtain a plurality of operating voltages; determining the instantaneous failure rate of the IGCT device corresponding to each of the operating voltages based on the failure rate and voltage relationship, including: determining the failure rate corresponding to each of the operating voltages in the failure rate and voltage relationship to obtain the instantaneous failure rate of the IGCT device corresponding to each of the operating voltages.

[0066] Specifically, it is necessary to monitor the operating voltage of the IGCT device in real time. Because the IGCT device in the converter valve operates in a high-voltage direct current transmission system, its voltage changes periodically over time, requiring continuous monitoring of the voltage across the IGCT device. During monitoring, a preset time interval covers the entire operating voltage cycle. The preset time interval needs to be short enough to capture the dynamic characteristics of voltage changes, while also considering data processing efficiency and accuracy. The operating voltage of the IGCT device is acquired at the midpoint of each preset time interval. Midpoint sampling more accurately reflects the voltage level experienced by the device within that time interval, avoiding calculation errors caused by voltage fluctuations. Through sampling at the midpoint, a series of voltage data points are obtained, distributed throughout the entire operating voltage cycle, representing the operating voltage state of the IGCT device at different time points. These voltage data points are then used as multiple operating voltages for failure rate calculation. This step essentially prepares input data for subsequent failure rate calculations, ensuring that the calculation results reflect the failure rate of the IGCT device at various time points within the operating voltage cycle.

[0067] The established failure rate-voltage relationship is used to match each operating voltage value collected at a midpoint within a preset time interval. In other words, for each voltage data point, the corresponding failure rate is matched against the failure rate-voltage relationship. Here, the failure rate is specific to a particular voltage value, i.e., the instantaneous failure rate. The parameters (such as a and b) in the failure rate-voltage relationship have undergone prior fitting and represent the relationship between the failure rate and voltage of the IGCT device under given environmental conditions (such as temperature and altitude). The failure rate corresponding to each voltage value obtained through the above steps is the instantaneous failure rate of the IGCT device at that operating voltage. Since voltage is a time-varying variable, the instantaneous failure rate also changes over time, reflecting the actual failure risk of the IGCT device within the operating voltage cycle.

[0068] Through the above steps, more accurate operating voltage data can be obtained during the operation of the IGCT device, which can then be used to calculate the average failure rate of the IGCT device within the actual operating voltage cycle. This effectively captures the instantaneous impact of voltage changes on the failure rate, avoiding the large errors that may occur when using only average voltage or a single voltage value for calculation, thus helping to improve the accuracy of the overall converter valve reliability assessment. Based on the relationship between the failure rate and voltage of the IGCT device, the instantaneous failure rate of the IGCT device under different operating voltages can be calculated in real time. Dynamically changing operating voltage values ​​can be substituted into a pre-built failure rate-voltage relationship for matching, thereby instantly obtaining the failure rate corresponding to each voltage value, improving the accuracy and timeliness of the failure rate assessment. Defining these failure rates under specific operating voltages as instantaneous failure rates more realistically reflects the failure risk of the IGCT device under actual operating conditions with voltage fluctuations, providing data support for the reliability analysis and performance optimization of converter valves in high-voltage direct current transmission systems.

[0069] In some embodiments of this application, after determining the failure rate of the converter valve based on the average failure rate and the valve group configuration parameters of the converter valve, the method further includes: real-time monitoring of the cosmic ray intensity of the IGCT device of the converter valve; and triggering an adjustment control strategy when the cosmic ray intensity is greater than a first preset threshold or the failure rate of the converter valve is greater than a second preset threshold. The adjustment control strategy includes at least one of the following: reducing the trigger voltage of the IGCT device to a preset range or increasing the flow rate of the cooling fluid to a preset flow rate range.

[0070] The core of this strategy lies in real-time monitoring of cosmic ray intensity and adjusting the operating parameters of the IGCT device when environmental conditions deteriorate or the failure rate of the converter valve exceeds a safe range, thereby mitigating the impact of environmental factors such as cosmic rays on device performance. Specifically, radiation monitoring sensors installed near the converter valve collect real-time data on the cosmic ray intensity of the environment in which the IGCT device operates. This monitoring can be continuous, ensuring that any sudden changes in cosmic ray intensity are detected. Once the monitored cosmic ray intensity exceeds a first preset threshold, or the failure rate of the converter valve exceeds a second preset threshold (i.e., exceeding a preset safety threshold), the control strategy adjustment phase begins. The trigger voltage of the IGCT device is adjusted to a safer preset range. Lowering the trigger voltage reduces the electrical stress on the IGCT device in a high-radiation environment, thereby reducing the failure rate. Simultaneously, the efficiency of the cooling system can be increased by increasing the flow rate of the cooling fluid, keeping the operating temperature of the IGCT device within a preset flow range. This effectively reduces the thermal stress on the IGCT device caused by high cosmic ray intensity, reducing the possibility of IGCT device failure.

[0071] Through the above embodiments, the IGCT devices in the converter valve can respond promptly to changes in environmental conditions, especially increases in cosmic ray intensity, during operation. This allows for preventative adjustments to the device's operating parameters, ensuring the overall reliability of the converter valve system remains unaffected. This method not only improves the system's resilience but also delays or avoids unplanned downtime caused by cosmic rays. Furthermore, it effectively manages the lifespan of the IGCT devices, reduces maintenance costs, and enhances the stability and economy of the high-voltage direct current transmission system.

[0072] In other embodiments of this application, the method further includes: using a preset neural network model to predict whether the IGCT device of the converter valve has a potential failure mode, the potential failure modes including cosmic ray-induced failure, overheating-induced failure, and voltage surge-induced failure modes, wherein the preset neural network model is constructed based on historical cosmic ray intensity, historical ambient temperature, historical operating voltage, and historical failure cases; if the IGCT device is in the potential failure mode, then preventive measures are activated, the preventive measures including at least one of the following: switching to a redundant path to avoid possible failure points, increasing monitoring of the backup IGCT device to respond to possible device failures, and adjusting the control parameters of the converter valve, the control parameters including the firing angle and cooling fluid flow rate. Further, adjusting the control parameters of the converter valve, the control parameters including the firing angle and cooling fluid flow rate, includes: adjusting the firing angle to reduce the conduction time of the IGCT device and increasing the cooling fluid flow rate to accelerate heat removal based on the current operating voltage of the IGCT device, the historical ambient temperature, and the historical failure cases.

[0073] The above embodiments analyze historical data, including cosmic ray intensity, ambient temperature, operating voltage, and historical failure cases caused by these conditions, using a neural network model. This model can predict whether the IGCT device may encounter cosmic ray-induced failures, overheating-induced failures, or voltage surge failure modes. Once the model predicts that the IGCT device may be in a potential failure mode, it automatically initiates a series of preventative measures to enhance system stability and safety. Switching to a backup or redundant power transmission path avoids IGCT devices that might cause primary path failures, ensuring continuous power supply. Increasing the monitoring intensity of backup IGCT devices allows for rapid response and activation of backup devices in the event of a primary IGCT device failure, reducing system downtime. Adjusting the control parameters of the converter valve, including the firing angle and cooling fluid flow rate, shortens the IGCT device's on-time, effectively reducing the device's current carrying capacity and thus reducing the risk of overheating damage. Simultaneously, increasing the cooling fluid flow rate accelerates heat removal, keeping the IGCT device's operating temperature within a safe range and further preventing overheating-related failures.

[0074] By employing a neural network model, the accuracy of predicting potential failures in IGCT devices is improved, enabling preventative measures to be taken in advance to avoid failures and thus enhance the overall operational stability and reliability. By reducing the firing angle and increasing the cooling fluid flow rate, the operating conditions of the IGCT devices are dynamically adjusted to ensure optimal operation, effectively extending device lifespan and reducing maintenance and replacement costs. The aforementioned control strategy can quickly respond to changes in environmental and operating conditions, adjusting control parameters in real time, improving response speed and flexibility in handling complex operating conditions. The preventative measures in this embodiment, particularly the adjustment of converter valve control parameters when potential failure modes are predicted, effectively mitigate risks and ensure the safe operation of the power system under extreme conditions such as cosmic rays, overheating, and voltage surges. In summary, intelligent prediction and precise control provide comprehensive protection for IGCT devices in hybrid DC transmission systems, ensuring efficient and stable operation even in the face of potential risks.

[0075] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the converter valve failure rate evaluation method of this application will be described in detail below with reference to specific embodiments.

[0076] This embodiment relates to a specific method for evaluating the failure rate of a converter valve. Taking the failure rate of an IGCT device as an example, cosmic ray failure rate tests of the IGCT device are conducted at different altitudes. Figure 2 The relationship between failure rate and applied voltage of IGCT devices at different altitudes (sea level, 2000m, 4000m, and 6000m) at 25℃ is presented. The blue curve represents the failure rate versus voltage relationship at sea level, the green curve represents the efficiency versus voltage relationship at 2000m altitude, the red curve represents the efficiency versus voltage relationship at 4000m altitude, and the black curve represents the efficiency versus voltage relationship at 6000m altitude.

[0077] The relationship between failure rate and voltage can be obtained through data fitting; see the formula. ,in, The instantaneous failure rate of the IGCT device. denoted as the operating voltage of the IGCT device, and a and b as fitting constants.

[0078] See Figure 3The blue line represents the typical operating voltage waveform of the IGCT device, and the red line represents the equivalent voltage waveform after processing by the differential averaging method. Based on the periodic change of the IGCT operating voltage waveform in the converter valve, the differential averaging method is used to extract the voltage across the IGCT at the same time interval (i.e., the preset time interval dt=0.5us). Combined with the above fitting, the corresponding voltage failure rate (instantaneous failure rate) is obtained. Using formula Calculations of IGCT failure rates at different altitudes were obtained. That is, the average failure rate, where, The average failure rate. For transient failure rate, This marks the start of the operating voltage cycle. This is the end time of the working voltage cycle.

[0079] After obtaining the equivalent failure rate of a single ICGT device under actual operating conditions, the failure rate of the converter valve can be calculated based on the number of IGCT devices used in a converter valve.

[0080] Taking the UHV IGCT converter valve as an example, the number of IGCTs in series in a single valve is N (i.e., the number of IGCT devices in series in a single valve is N). A dual 12-pulse design is adopted. Considering positive and negative polarities, the number of individual valves in a ±800kV converter valve is 48. The cosmic ray failure characteristic of IGCT devices is random time, and the failure probability of each device is the same. The formula is used... The overall failure probability of the IGCT converter valve, i.e., the failure rate of the converter valve, can then be calculated.

[0081] Comprehensive formula ,formula and formula It can be concluded that In practical applications, the formula is used. Calculate the failure rate of the converter valve, where, The failure rate of the converter valve. The number of individual valves in the converter valve system. The number of IGCT devices in series in each individual valve. Let be the operating voltage of the IGCT device, and a and b be fitting constants. This marks the start of the operating voltage cycle. This is the end time of the working voltage cycle.

[0082] formula The relationship between the operating voltage and failure rate of UHV converter valves was summarized, and a reliability assessment model for converter valves was constructed to calculate the failure rate of converter valves under different altitudes, control strategies, and operating conditions. The reliability assessment process for IGCT converter valves is described in [link to relevant documentation]. Figure 4 First, the failure rate curve of the IGCT device is obtained. Through curve fitting, the relationship between the failure rate and operating voltage of the IGCT device at different altitudes is derived. Then, combined with the topology and electrical design scheme of the UHV converter valve, the relationship between the overall failure rate and operating voltage of the converter valve is obtained, thus yielding the model of the relationship between the overall failure rate and operating voltage of the converter valve. The above model is used to evaluate the failure rate of the converter valve under different altitudes, control strategies, and operating conditions. The control strategy refers to different control strategies for the converter valve, such as firing angle adjustment, re-firing frequency, and cooling strategy, all of which affect the operating status and failure rate of the IGCT. Operating conditions, such as the IGCT's operating temperature, operating voltage, and current load, especially the time-series data of the operating voltage, are crucial for calculating the instantaneous failure rate. Since different altitudes, control strategies, and operating conditions all affect the operating voltage of the IGCT device, and this application can determine the failure rate of the converter valve under different operating voltages, different operating voltages can characterize different altitudes, control strategies, and operating conditions.

[0083] This embodiment, based on the curves of IGCT cosmic ray failure rate versus operating voltage and temperature at a specific altitude, combined with the converter valve's operating voltage waveform, accurately assesses the converter valve failure rate under actual operating conditions using a differential weighted average failure rate calculation strategy. This solves the problem of large errors when using a single voltage to calculate the converter valve failure rate. The resulting model of the overall converter valve failure rate versus operating voltage can calculate the converter valve failure rate under different control strategies and operating conditions, providing a reference for improving converter valve reliability. The converter valve in this embodiment is an IGCT converter valve. This IGCT converter valve reliability assessment process can be extended to applications such as thyristor converter valves and IGBT converter valves, standardizing the reliability assessment process for DC transmission converter valves.

[0084] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the converter valve failure rate assessment method.

[0085] This invention also provides a DC transmission system, see [link to relevant documentation]. Figure 5 The aforementioned DC transmission system includes a sending end, a receiving end, and a controller. The sending end includes a sending-end converter valve, which comprises multiple converter valve assemblies, each including an IGCT device. The receiving end includes a receiving-end converter valve, which comprises multiple converter valve assemblies, each including an IGCT device. The controller is connected to both the sending-end and receiving-end converter valves and is used to execute any of the aforementioned converter valve failure rate assessment methods. Taking the sending end as an example, see [link to relevant documentation]. Figure 5The aforementioned feed end 01 includes a feed end converter valve 10, the aforementioned feed end converter valve 10 includes a plurality of converter valve assemblies 101, each of the aforementioned converter valve assemblies 101 includes an IGCT device 1011, and the controller 02 is connected to the aforementioned feed end converter valve 10.

[0086] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0092] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, like read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0093] 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, 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.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] 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 process, method, article, or apparatus. Unless otherwise specified, 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 that element.

[0096] The above description is merely a preferred embodiment of this application and is not intended to limit 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 protection scope of this application.

Claims

1. A method for evaluating the failure rate of a converter valve, characterized in that, include: Within one operating voltage cycle of the IGCT device of the converter valve, the operating voltage of the IGCT device within each of the preset time intervals is obtained to obtain multiple operating voltages, wherein the multiple preset time intervals do not overlap. The instantaneous failure rate of the IGCT device corresponding to each operating voltage is determined based on the failure rate-voltage relationship. The failure rate-voltage relationship characterizes the correspondence between the instantaneous failure rate of the IGCT device and its operating voltage. The failure rate-voltage relationship is constructed based on environmental parameters, including temperature and altitude. Based on the instantaneous failure rate and the operating voltage period, the average failure rate of the IGCT device during the operating voltage period is determined; The failure rate of the converter valve is determined based on the average failure rate and the valve group configuration parameters of the converter valve, wherein the valve group configuration parameters include the number of individual valves of the converter valve and the number of IGCT devices in series in each individual valve.

2. The method according to claim 1, characterized in that, Based on the instantaneous failure rate and the operating voltage period, the average failure rate of the IGCT device during the operating voltage period is determined, including: Obtain the start time and end time of the operating voltage cycle; The instantaneous failure rate is integrated to obtain the integrated instantaneous failure rate. The average failure rate of the IGCT device during the operating voltage cycle is determined based on the integrated instantaneous failure rate, the start time of the operating voltage cycle, and the end time of the operating voltage cycle.

3. The method according to claim 2, characterized in that, The average failure rate of the IGCT device during the operating voltage cycle is determined based on the integrated instantaneous failure rate, the start time of the operating voltage cycle, and the end time of the operating voltage cycle, including: Calculate the difference between the end time and the start time of the working voltage cycle to obtain the total duration of the working voltage cycle; The average failure rate is obtained by calculating the ratio of the integrated instantaneous failure rate to the total duration of the operating voltage cycle.

4. The method according to claim 1, characterized in that, Determining the failure rate of the converter valve based on the average failure rate and the valve group configuration parameters of the converter valve includes: The product of the number of individual valves in the converter valve and the number of IGCT devices in each individual valve is calculated to obtain the product value; The failure rate of the converter valve is obtained by multiplying the average failure rate by the product value.

5. The method according to claim 1, characterized in that, Before determining the instantaneous failure rate of the IGCT device corresponding to each of the said operating voltages based on the failure rate-voltage relationship, the method further includes: Obtain the failure rate of the IGCT device at different operating voltages under different environmental parameters; The relationship between the failure rate and voltage under different environmental parameters is determined based on the failure rate corresponding to different operating voltages under different environmental parameters.

6. The method according to claim 5, characterized in that, Obtaining the failure rate of the IGCT device at different operating voltages under different environmental parameters includes: For each temperature point within a preset temperature range, the failure rate of the IGCT device corresponding to different operating voltages at different altitudes is obtained, resulting in multiple first failure rate groups at each temperature point. Each first failure rate group corresponds to an altitude, and each first failure rate group includes multiple failure rates corresponding to the operating voltage.

7. The method according to claim 6, characterized in that, Determining the relationship between failure rate and voltage under different environmental parameters based on the failure rate corresponding to different operating voltages under different environmental parameters includes: Based on the N first failure rate groups at each temperature point, the failure rate and voltage relationship at different altitudes are determined, resulting in (N×M) first failure rate and voltage relationships, where N is the number of different altitudes at each temperature point and M is the number of temperature points. The failure rate and voltage relationship under different environmental parameters are determined based on (N×M) first failure rate and voltage relationships.

8. The method according to claim 1, characterized in that, Within one operating voltage cycle of the IGCT device of the converter valve, the operating voltage of the IGCT device is acquired within each of multiple preset time intervals to obtain multiple operating voltages. These preset time intervals do not overlap. The operating voltage of the IGCT device is monitored, and the operating voltage of the IGCT device is acquired at the midpoint of each preset time interval within the operating voltage cycle to obtain multiple operating voltages; Determining the instantaneous failure rate of the IGCT device corresponding to each of the aforementioned operating voltages based on the failure rate-voltage relationship includes: By determining the failure rate in the relationship between failure rate and voltage, and the failure rate corresponding to each of the operating voltages, the instantaneous failure rate of the IGCT device corresponding to each of the operating voltages is obtained.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the converter valve failure rate assessment method according to any one of claims 1 to 8.

10. A direct current transmission system, characterized in that, include: The feed end includes a feed end converter valve, which includes multiple converter valve assemblies, each of which includes an IGCT device. The receiving end includes a receiving end converter valve, which includes multiple converter valve assemblies, each of which includes an IGCT device. The controller is connected to the sending-end switching valve and the receiving-end switching valve respectively, and is used to execute the switching valve failure rate assessment method according to any one of claims 1 to 8.

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