Controllable series capacitance compensation dynamic simulation device and method

Abstract

The application is suitable for the technical field of power system dynamic simulation, and provides a controllable series capacitor compensation dynamic simulation device and method, and the controllable series capacitor compensation dynamic simulation device comprises a data acquisition unit, which is used for collecting a capacitor voltage peak value, a voltage change rate, a current zero-crossing point offset, a trigger angle change rate, a cumulative conduction frequency, a current operating temperature and a power grid frequency in real time; and a transient stress index generation unit connected with the normalization processing unit, which is used for fusing four normalized basic components and outputting a transient stress index. In the application, the capacitor voltage peak value, the voltage change rate, the current zero-crossing point offset and the trigger angle change rate are normalized and weightedly fused to generate the transient stress index, so that the cumulative stress risk under the joint action of multiple parameters can be identified, and the false triggering protection caused by the single parameter transient over-limiting can be avoided.

Description

Technical Field

[0001] This invention belongs to the field of dynamic simulation technology of power systems, and particularly relates to a controllable series capacitor compensation dynamic simulation device. Background Technology

[0002] Controllable series capacitor compensation devices, as core components of flexible AC transmission systems, achieve power flow control and system stability improvement by dynamically adjusting the equivalent impedance of the line, playing a crucial role in power system dynamic simulation and device testing. Existing simulation devices face multiple technical challenges during operation, particularly exhibiting significant deficiencies in the instantaneous electrical stress assessment stage.

[0003] Traditional devices employ isolated monitoring mechanisms for key parameters such as peak capacitor voltage, rate of change of voltage, current zero-crossing offset, and rate of change of firing angle, each with its own independent protection threshold. When multiple parameters simultaneously approach dangerous limits but none individually exceed them, the system fails to identify cumulative stress risks, leading to missed optimal intervention opportunities. Conversely, when a single parameter briefly exceeds its limit due to a transient disturbance, it easily triggers unnecessary protective actions, causing system misjudgments. This fragmented parameter processing stems from the lack of an effective multi-dimensional integrated evaluation mechanism in current technology, making it impossible to establish quantitative indicators that reflect the comprehensive stress state.

[0004] Furthermore, the existing device does not perform correlation analysis between instantaneous stress state and the aging process of the device, which makes the firing angle control strategy rely on a single feedback signal, making it difficult to achieve a dynamic balance between operational safety and compensation efficiency.

[0005] The aforementioned deficiencies severely limit the simulation device's ability to reproduce real-world operating conditions, leading to discrepancies between test results and actual operation, and affecting the reliability of control strategy verification. Therefore, existing technologies urgently need improvement to address these issues. Summary of the Invention

[0006] The purpose of this invention is to provide a controllable series capacitor compensation dynamic simulation device to solve the above-mentioned problems.

[0007] This invention is implemented as follows: a controllable series capacitor compensation dynamic simulation device, comprising:

[0008] The data acquisition unit is used to collect capacitor voltage peak value, voltage change rate, current zero-crossing offset, firing angle change rate, cumulative conduction count, current operating temperature and grid frequency in real time.

[0009] The normalization processing unit, connected to the data acquisition unit, is used to normalize the four original parameters: peak capacitor voltage, rate of change of voltage, current zero-crossing offset, and rate of change of firing angle, and outputs the peak capacitor voltage component, rate of change of voltage component, current zero-crossing offset component, and rate of change of firing angle component, respectively.

[0010] The instantaneous stress index generation unit, connected to the normalization processing unit, is used to fuse the four normalized basic components and output the instantaneous stress index.

[0011] An aging coefficient generation unit, connected to the data acquisition unit, is used to output the device aging coefficient based on the cumulative number of conductions and the current operating temperature.

[0012] The comprehensive evaluation index generation unit is connected to the instantaneous stress index generation unit, the aging coefficient generation unit, and the data acquisition unit, respectively. It is used to obtain the power grid frequency deviation coefficient and integrate the instantaneous stress index, the device aging coefficient, and the frequency deviation coefficient to output the comprehensive evaluation index.

[0013] The trigger angle update unit is connected to the comprehensive evaluation index generation unit and is used to output the updated trigger angle based on the comprehensive evaluation index, the maximum allowable change in trigger angle in a single step, and the current trigger angle.

[0014] A further technical solution, the data acquisition unit includes:

[0015] Peak normalization subunit, used to calculate the peak normalized component of capacitor voltage. :

[0016]

[0017] in This is the measured peak value of the capacitor voltage. This refers to the safe threshold voltage for the capacitor.

[0018] The rate-of-change normalization sub-unit is used to calculate the voltage rate-of-change components. :

[0019]

[0020] in This is the measured value of the capacitor voltage change rate. This represents the device's tolerance limit.

[0021] Zero-crossing offset normalized sub-unit, used to calculate the current zero-crossing offset component. :

[0022]

[0023] in This is the measured absolute value of the current zero-crossing offset. This is the maximum allowed offset;

[0024] The normalized firing angle rate of change sub-unit is used to calculate the firing angle rate of change components. :

[0025]

[0026] in The absolute value of the rate of change of the firing angle is the measured value. The maximum allowable rate of change; the values ​​of each normalized component are all in the range of [0,1].

[0027] In a further technical solution, the instantaneous stress index generation unit calculates the instantaneous stress index using the following weighted summation formula. :

[0028]

[0029] in The peak weighting coefficient. The rate of change weighting coefficient. The zero-crossing offset weighting coefficient, This is the weighting coefficient for the rate of change of the firing angle. , , as well as All are greater than 0, and .

[0030] A further technical solution includes a weight self-calibration unit, which is connected to both the normalization processing unit and the instantaneous stress index generation unit, and is used to perform real-time self-calibration of the weight coefficients.

[0031] The weighted self-calibration unit calculates the historical average values ​​of the capacitor voltage peak normalized component, voltage change rate component, current zero-crossing offset component, and firing angle change rate component before the most recent M overvoltage events in each calibration cycle.

[0032] The weight self-correction unit compares the absolute value of the deviation between the historical average value of each normalized component and the safety threshold. The larger the absolute value of the deviation, the greater the weight. Specifically, the weight of the component with the largest deviation between the historical average value and the safety threshold is increased by a fixed step, the weight of the component with the smallest deviation is decreased by a fixed step, and the weights of the other two components remain unchanged. After adjustment, all weights are greater than 0 and their sum is 1.

[0033] In a further technical solution, the aging coefficient generation unit calculates the device aging coefficient using the following formula. :

[0034]

[0035] in To accumulate the number of times the signal is activated, The maximum number of times the device can be switched on within its rated lifespan. The current operating temperature. These are reference temperatures, and both are Kelvin temperatures; This represents the temperature acceleration factor coefficient.

[0036] A further technical solution is that the comprehensive evaluation index generation unit calculates the power grid frequency deviation coefficient according to the following formula. :

[0037]

[0038] in, To measure the power grid frequency, For the rated frequency, The maximum allowable frequency deviation;

[0039] The comprehensive evaluation index is then calculated using the following formula. :

[0040]

[0041] in .

[0042] In a further technical solution, the trigger angle update unit calculates the updated trigger angle using the following formula:

[0043]

[0044] in The current trigger angle. To trigger the corner update value, This represents the maximum permissible change in trigger angle per step. To comprehensively evaluate the reference threshold of the index, , For symbolic functions, For input values, when When the value is greater than 0, the value is 1. When =0, the value is 0. When the value is less than 0, the value is -1.

[0045] A controllable series capacitor compensation dynamic simulation method, applied to any of the above-described devices, includes:

[0046] S1. Real-time acquisition of capacitor voltage peak value, voltage change rate, current zero-crossing offset, firing angle change rate, cumulative conduction count, current operating temperature and grid frequency;

[0047] S2. Normalize the four original parameters, namely, peak capacitor voltage, rate of change of voltage, current zero-crossing offset, and rate of change of firing angle, to obtain four normalized basic components, including the peak capacitor voltage component, the rate of change of voltage component, the current zero-crossing offset component, and the rate of change of firing angle component.

[0048] S3. Fuse the four normalized basic components from step S2 to generate the instantaneous stress index;

[0049] S4. Generate the device aging coefficient based on the cumulative number of conduction cycles and the current operating temperature;

[0050] S5. Obtain the power grid frequency deviation coefficient, and integrate the instantaneous stress index, device aging coefficient, and frequency deviation coefficient to generate a comprehensive evaluation index;

[0051] S6. Based on the comprehensive evaluation index, the maximum allowable change in trigger angle per step, and the current trigger angle, output the updated trigger angle.

[0052] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0053] 1. In this invention, by normalizing and weighting four key parameters—capacitor voltage peak value, voltage change rate, current zero-crossing offset, and trigger angle change rate—to generate an instantaneous stress index, it is possible to identify the cumulative stress risk under the combined effect of multiple parameters, avoid false triggering of protection caused by a single parameter instantaneously exceeding the limit, and also prevent the risk of missed detection when multiple parameters are close to the limit but none of them exceed the limit individually.

[0054] 2. In this invention, the aging coefficient generation unit calculates the device aging coefficient based on the cumulative number of conduction cycles and the current operating temperature, and introduces a temperature acceleration factor exponential function to truly reflect the accelerating effect of temperature on the device aging rate. This avoids the overestimation of remaining lifespan by traditional linear conversion, and improves the accuracy of aging assessment and the safety of device operation.

[0055] 3. In this invention, the comprehensive evaluation index generation unit multiplicatively integrates the instantaneous stress index, the device aging coefficient, and the power grid frequency deviation coefficient to form a unified risk quantification index; the trigger angle update unit adaptively adjusts the direction and amplitude of the trigger angle accordingly, realizing a coordinated control mechanism of "stress-aging-frequency", which significantly improves the simulation device's reproduction of real operating characteristics and the reliability of control strategy verification.

[0056] 4. In this invention, the weight self-correction unit dynamically adjusts the weight coefficients of each component in the instantaneous stress index based on the deviation between the historical average value before the overvoltage event and the safety threshold. This enables the device to automatically identify the main stress factors under the current operating conditions, avoiding the risk assessment inaccuracy problem caused by static weights and improving the sensitivity and adaptability of the instantaneous stress index. Attached Figure Description

[0057] Figure 1 A schematic diagram of the unit structure of a controllable series capacitor compensation dynamic simulation device;

[0058] Figure 2 This is a schematic diagram illustrating the steps of a dynamic simulation method for controllable series capacitor compensation. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0060] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0061] like Figure 1 As shown, a controllable series capacitor compensation dynamic simulation device according to an embodiment of the present invention includes:

[0062] The data acquisition unit is used to collect capacitor voltage peak value, voltage change rate, current zero-crossing offset, firing angle change rate, cumulative conduction count, current operating temperature and grid frequency in real time.

[0063] The normalization processing unit, connected to the data acquisition unit, is used to normalize the four original parameters: peak capacitor voltage, rate of change of voltage, current zero-crossing offset, and rate of change of firing angle, and outputs the peak capacitor voltage component, rate of change of voltage component, current zero-crossing offset component, and rate of change of firing angle component, respectively.

[0064] The instantaneous stress index generation unit, connected to the normalization processing unit, is used to fuse the four normalized basic components and output the instantaneous stress index.

[0065] An aging coefficient generation unit, connected to the data acquisition unit, is used to output the device aging coefficient based on the cumulative number of conductions and the current operating temperature.

[0066] The comprehensive evaluation index generation unit is connected to the instantaneous stress index generation unit, the aging coefficient generation unit, and the data acquisition unit, respectively. It is used to obtain the power grid frequency deviation coefficient and integrate the instantaneous stress index, the device aging coefficient, and the frequency deviation coefficient to output the comprehensive evaluation index.

[0067] The trigger angle update unit is connected to the comprehensive evaluation index generation unit and is used to output the updated trigger angle based on the comprehensive evaluation index, the maximum allowable change in trigger angle in a single step, and the current trigger angle.

[0068] In this embodiment, the controllable series capacitor compensation dynamic simulation device is a device used to simulate the operating characteristics of a controllable series capacitor compensation device. This device verifies the effectiveness of the control strategy and the reliability of the device by simulating the behavior of the TCSC in a power system, such as power flow control, transmission capacity enhancement, and system stability improvement.

[0069] The peak capacitor voltage refers to the maximum instantaneous value of the voltage across the capacitor in a controllable series capacitor compensation device within each cycle. This parameter reflects the instantaneous electrical stress level experienced by the capacitor. The rate of change of voltage refers to the rate at which the voltage across the capacitor changes over time. A high rate of change of voltage can cause excessive instantaneous shocks to the device and is an important indicator for assessing device stress. The current zero-crossing offset refers to the deviation between the current waveform flowing through the thyristor valve group and the ideal zero-crossing point. This offset reflects the conduction state and control accuracy of the thyristor; excessive offset can lead to unwanted harmonics or control instability. The firing angle change rate refers to the rate at which the thyristor firing angle changes over time. The firing angle is a key parameter for controlling the thyristor's conduction timing; rapid changes in this angle can lead to system oscillations or control instability. The cumulative number of conduction cycles refers to the cumulative number of conduction operations of the thyristor valve group throughout its entire operating life. This parameter is an important indicator for assessing the fatigue aging degree of the thyristor. The current operating temperature refers to the real-time operating temperature inside the controllable series capacitor compensation device, especially the thyristor valve group. High temperatures accelerate the aging process of semiconductor devices and have a significant impact on the device's lifespan. Grid frequency refers to the frequency of alternating current in a power system. Deviations in grid frequency can affect the stable operation of the power system and the control strategies of TCSC devices.

[0070] Normalization is a data preprocessing technique used to transform data with different dimensions or numerical ranges into a unified interval, so as to facilitate comparison and fusion between different parameters.

[0071] The instantaneous stress index is a comprehensive indicator used to quantify the instantaneous electrical stress level experienced by a controllable series capacitor compensation device at a given moment. This index is generated by integrating multiple parameters reflecting instantaneous stress. The device aging coefficient is an indicator that quantifies the current degree of aging of the device. This coefficient comprehensively considers the impact of the device's cumulative operating time and operating environment (such as temperature) on its lifespan.

[0072] The grid frequency deviation coefficient is an indicator that quantifies the degree to which the grid frequency deviates from its rated value. This coefficient reflects the stability of the grid's operating conditions. The comprehensive evaluation index is a quantitative indicator that comprehensively reflects the current operating status of the controllable series capacitor compensation device. This index is generated by integrating the instantaneous stress index, the device aging coefficient, and the grid frequency deviation coefficient, providing a basis for the device's control decisions.

[0073] The firing angle is a key parameter controlling the turn-on time of a thyristor. By adjusting the firing angle, the equivalent reactance of the controllable series capacitor compensation device can be changed, thereby achieving control over the power flow of the power system. The maximum permissible change in firing angle per step refers to the maximum allowable adjustment of the firing angle within one control cycle. This parameter is used to limit the drastic nature of the firing angle adjustment to ensure the stability of system operation.

[0074] This embodiment comprehensively acquires multi-dimensional operating parameters through a data acquisition unit, and a normalization processing unit uniformly processes the instantaneous stress-related parameters. Subsequently, an instantaneous stress index generation unit merges these normalized components into a single instantaneous stress index. For example, in the above example, even if each instantaneous stress parameter individually does not reach its limit, their combined effect may already pose a high risk. This solution, through fusion, can accurately quantify this cumulative stress, avoiding the blind spots of traditional solutions.

[0075] Furthermore, in simulating device aging effects, existing methods often rely solely on linear calculations based on the cumulative number of on-time cycles, neglecting the accelerating effect of temperature on device aging rates. For example, in the aforementioned example, if the device operates at a higher temperature, its aging rate will significantly accelerate. The aging coefficient generation unit in this embodiment calculates the device aging coefficient based on both the cumulative number of on-time cycles and the current operating temperature, more accurately reflecting the temperature-accelerated aging effect in actual physical processes. This avoids overestimating the remaining lifespan of the device and improves the realism of the simulation.

[0076] Furthermore, existing devices often employ open-loop or closed-loop regulation based on a single feedback signal in their firing angle control strategies, failing to comprehensively assess instantaneous stress, device aging, and grid frequency deviation. For example, in the above example, adjusting the firing angle solely based on line current may not adequately account for the device's existing aging or abnormal fluctuations in grid frequency. The comprehensive evaluation index generation unit in this embodiment organically integrates the instantaneous stress index, device aging coefficient, and grid frequency deviation coefficient to output a comprehensive evaluation index. Consequently, the firing angle update unit can adaptively adjust the direction and amplitude of the firing angle based on this index, which comprehensively reflects the device's current overall operating status. This "stress-aging-frequency" coordinated adaptive firing angle update mechanism makes the control decisions of the simulation device more scientific and precise, significantly improving the dynamic simulation device's reproduction of the operating characteristics of a real controllable series capacitor compensation device, and providing a more reliable platform for verifying control strategies and evaluating device reliability.

[0077] In a preferred embodiment of the present invention, the data acquisition unit includes:

[0078] Peak normalization subunit, used to calculate the peak normalized component of capacitor voltage. :

[0079]

[0080] in This is the measured peak value of the capacitor voltage. This refers to the safe threshold voltage for the capacitor.

[0081] The rate-of-change normalization sub-unit is used to calculate the voltage rate-of-change components. :

[0082]

[0083] in This is the measured value of the capacitor voltage change rate. This represents the device's tolerance limit.

[0084] Zero-crossing offset normalized sub-unit, used to calculate the current zero-crossing offset component. :

[0085]

[0086] in This is the measured absolute value of the current zero-crossing offset. This is the maximum allowed offset;

[0087] The normalized firing angle rate of change sub-unit is used to calculate the firing angle rate of change components. :

[0088]

[0089] in The absolute value of the rate of change of the firing angle is the measured value. The maximum allowable rate of change; the values ​​of each normalized component are all in the range of [0,1].

[0090] In this embodiment, the peak normalization subunit is a module specifically designed for processing capacitor voltage peak data. It receives the real-time measured value of the capacitor voltage peak. In conjunction with a preset capacitor voltage safety threshold Through calculation and The ratio is compared with the value 1, and the minimum value is taken to obtain the normalized component of the capacitor voltage peak. This subunit can be implemented by specific software functions in an embedded processor, or by digital logic circuitry within a programmable logic device.

[0091] The rate-of-change normalization subunit focuses on processing the rate of change of capacitor voltage. It obtains the measured value of the rate of change of capacitor voltage. and refer to the device tolerance limit This sub-unit is also calculated. and The ratio is compared with the value 1, and the minimum value is taken to generate the voltage change rate component. The implementation of this sub-unit can include digital signal processing algorithms running on a microcontroller, or it can employ analog differentiating circuits combined with analog-to-digital converters and digital processing modules.

[0092] The zero-crossing offset normalization sub-unit is responsible for processing the current zero-crossing offset. It receives the measured absolute value of the current zero-crossing offset. And based on the maximum allowable offset Perform normalization calculations. By... and The ratio is compared with the value 1 and the minimum value is taken. This is the zero-crossing offset component of the output current of this sub-unit. This subunit can be implemented by a microprocessor equipped with a timer / counter module for precise time offset measurement and subsequent normalization operations, or by dedicated digital logic circuitry.

[0093] The trigger angle change rate normalization subunit is used to process the trigger angle change rate information. It obtains the measured absolute value of the trigger angle change rate. and with the maximum permissible rate of change As a benchmark, this sub-unit is calculated. and The ratio is compared with the value 1, and the minimum value is taken to obtain the normalized component of the trigger angle change rate. This sub-unit can be implemented using a differential algorithm executed by a digital signal processor, or by processing continuously acquired trigger angle data through a software module.

[0094] The above-mentioned capacitor voltage safety threshold Device tolerance limit Maximum allowable offset and the maximum permissible rate of change All of these are preset fixed parameters, which are determined based on the electrical design specifications of the controllable series capacitor compensation device, the tolerance of key components such as thyristors, and the safety margin of system operation.

[0095] This application's solution integrates the aforementioned four dedicated normalization subunits into the data acquisition unit, achieving accurate and robust normalization of four key instantaneous electrical stress parameters: peak capacitor voltage, voltage change rate, current zero-crossing offset, and firing angle change rate. The data acquisition unit first acquires the measured values ​​of these raw parameters in real time. Subsequently, these measured values ​​are fed into the corresponding normalization subunits. Each subunit employs a truncated normalization method based on a safety threshold or limit value, i.e., calculating the ratio of the measured value to a preset safety threshold or tolerance limit, and taking the minimum value between this ratio and 1 as the normalization result. This calculation method ensures that all normalized components... , , and The values ​​of all parameters are strictly limited to [0,1]. When the measured value is much lower than its corresponding safety threshold or limit, the normalized component will reflect its relative magnitude; when the measured value reaches or exceeds its safety threshold or limit, the normalized component will be truncated to 1, thus clearly indicating that the parameter has reached or exceeded the critical state. This unified normalization method not only gives parameters of different physical dimensions a unified physical meaning—that is, the degree to which they approach the danger limit—but also naturally possesses the ability to resist outlier interference, avoiding distortion of normalization results caused by instantaneously large abnormal values ​​of the sensor.

[0096] In a preferred embodiment of the present invention, the instantaneous stress index generation unit calculates the instantaneous stress index using the following weighted summation formula. :

[0097]

[0098] in The peak weighting coefficient. The rate of change weighting coefficient. The zero-crossing offset weighting coefficient, This is the weighting coefficient for the rate of change of the firing angle. , , as well as All are greater than 0, and .

[0099] In this embodiment, the instantaneous stress index generation unit is a functional module in the device. Its main function is to receive multiple normalized components from the normalization processing unit and fuse these components into a single instantaneous stress index according to a preset algorithm. This unit can be implemented by dedicated hardware circuitry, such as using a digital signal processor or field-programmable gate array for high-speed parallel computing; or it can be implemented by software algorithms running on a general-purpose microcontroller (such as an ARM processor) or an industrial control computer.

[0100] Instantaneous stress index It is a quantitative value used to comprehensively characterize the electrical stress level experienced by a controllable series capacitor compensation dynamic simulation device at the current moment. Its value range is usually limited to 0 to 1, where a higher value indicates that the device is experiencing greater stress and is closer to its operating limit.

[0101] Peak weighting coefficient Change rate weighting coefficient Zero-crossing offset weighting coefficient , trigger angle change rate weighting coefficient These coefficients are parameters used to adjust the relative importance of each normalized component in the calculation of the instantaneous stress index. They reflect the differences in the degree of influence of different electrical parameters on the instantaneous stress of the device. For example, under certain operating conditions, the peak capacitor voltage may have a greater impact on the stress of the device, and its corresponding weighting coefficient... This will result in a relatively large value being assigned. These weighting coefficients can be determined based on the device's design specifications, operational experience, and historical data analysis.

[0102] Normalized components , , , These are normalized input parameters, representing the degree to which the peak capacitor voltage, rate of change of voltage, current zero-crossing offset, and rate of change of firing angle approach their safe threshold or limit value. They are typically dimensionless and their values ​​are limited to between 0 and 1, allowing parameters of different physical quantities to be compared and integrated on a unified scale.

[0103] As one specific implementation, the instantaneous stress exponent generation unit can be implemented by an embedded controller, such as an STM32 series microcontroller. This microcontroller receives four normalized components from the normalization processing unit. , , , These components can be in floating-point or fixed-point form. The software program inside the microcontroller performs a weighted summation operation. For example, suppose at a certain moment, the peak component of the capacitor voltage... The voltage change rate component is 0.6. The current zero-crossing offset component is 0.3. The firing angle rate of change component is 0.2. The value is 0.1. Meanwhile, the preset weighting coefficients are respectively... =0.4, =0.3, =0.2, =0.1. These weighting coefficients satisfy the condition that they are all greater than 0 and their sum is 1. At this point, the calculation process for the instantaneous stress index λ is: λ = 0.4 × 0.6 + 0.3 × 0.3 + 0.2 × 0.2 + 0.1 × 0.1 = 0.38. The calculated result 0.38 is the instantaneous stress index at the current moment. The microcontroller can perform this calculation periodically, for example, every few milliseconds or tens of milliseconds, to update the instantaneous stress index in real time. The initial setting of the weighting coefficients can be based on the electrical characteristics analysis and operating experience of the device. For example, if experience shows that the peak capacitor voltage has the greatest impact on the device's lifespan, a larger weight can be assigned to it.

[0104] Through the weighted fusion mechanism in the above formula, this scheme effectively overcomes the limitations of traditional independent threshold judgment methods, namely, the inability to identify cumulative stress risks under the combined effect of multiple parameters, and the problem of misjudgment due to the instantaneous exceeding of limits by a single parameter. The normalization processing unit converts the original electrical parameters with different dimensions and ranges into unified normalized components within the range of 0 to 1, providing standardized input for the weighted summation of the instantaneous stress index generation unit. This synergistic effect enables the instantaneous stress index to accurately reflect the true state of the device under multi-dimensional electrical stress, providing a more refined and reliable basis for the dynamic simulation and control of the device.

[0105] In a preferred embodiment of the present invention, a weight self-correction unit is further included. The weight self-correction unit is connected to the normalization processing unit and the instantaneous stress index generation unit, respectively, and is used to perform real-time self-correction on the weight coefficients.

[0106] The weighted self-calibration unit normalizes the peak value component of the capacitor voltage in each calibration cycle. Voltage change rate component Current zero-crossing offset component and the firing angle rate of change component Substituting these values ​​into the formula, we can calculate their historical average values ​​prior to the most recent M overvoltage events, thus obtaining the historical average value of the peak normalized component. Historical average of the normalized component of the rate of change Historical average value of the zero-crossing offset normalized component and the historical average of the normalized component of the rate of change of firing angle. The calculation formula is:

[0107]

[0108] in Input parameter value , , as well as One of them, It is the first Normalized component values ​​prior to the overvoltage event The input parameter value corresponds to the historical average value;

[0109] The weighted self-correction unit compares the historical average values ​​of each normalized component. , , as well as The absolute value of the deviation from the safety threshold; the larger the absolute value of the deviation, the higher the weight. Specifically, , The component with the smallest deviation corresponds to a weight reduction of a fixed step size. The weights of the other two components remain unchanged. After adjustment, each weight is greater than 0 and the sum is 1. The value of M ranges from 5 to 20, and the value of the safety threshold ranges from 0.5 to 0.7.

[0110] In this embodiment, the weight self-calibration unit is a functional module whose main responsibility is to dynamically adjust the weight coefficients used to calculate the instantaneous stress index based on the device's operating status and historical data. This unit can be implemented by an embedded controller, with complex algorithm logic programmed; alternatively, its function can be integrated into the host computer monitoring software as part of the data processing and decision-making module.

[0111] The weight self-calibration unit establishes a connection with the normalization processing unit and the instantaneous stress index generation unit to achieve efficient data transmission and effective command interaction. This connection can be physical, such as through a high-speed serial communication interface for digital signal transmission, ensuring that the real-time data output by the normalization processing unit is accurately delivered to the weight self-calibration unit, while the adjusted weight coefficients from the weight self-calibration unit are promptly transmitted to the instantaneous stress index generation unit. Alternatively, it can be logical, such as within a unified software platform, enabling data exchange between modules through shared memory regions or message queue mechanisms.

[0112] Real-time self-calibration of weighting coefficients refers to the ability of the weighting self-calibration unit to adjust the weighting coefficients periodically or under the trigger of specific events during device operation, according to a preset algorithm. This real-time capability can be achieved by setting a fixed calibration period (e.g., performing calibration once per second) or by using an event-driven mechanism (e.g., triggering calibration immediately after each overvoltage event is detected), to ensure that the weighting coefficients always adapt to the current operating conditions.

[0113] Within each correction cycle, the historical average value of each normalized component before the most recent M overvoltage events is calculated. This process involves data storage, retrieval, and statistical calculation. The weighted self-calibration unit can maintain a circular buffer or historical data queue to store the values ​​of each normalized component before the most recent M overvoltage events. When a new overvoltage event occurs, the current normalized component value is recorded, and the buffer is updated.

[0114] Subsequently, the historical average value of each component is obtained by arithmetically averaging the M historical data in the buffer. The core logic of weight self-calibration is to compare the absolute value of the deviation between each normalized component and the safety threshold, and adjust the weights according to the magnitude of the deviation. The weight self-calibration unit calculates the absolute difference between the historical average value of each normalized component and the preset safety threshold. Then, it identifies the component with the largest and smallest absolute deviation. According to preset rules, the weight corresponding to the component with the largest absolute deviation value will be increased by a fixed step. The weight corresponding to the component with the smallest absolute deviation will be reduced by the same fixed step size. The weights of the other two components remain unchanged. During the adjustment process, the weight self-correction unit ensures that all weight coefficients remain greater than 0 after adjustment and that their sum remains 1, in order to maintain the validity of the weighted summation formula.

[0115] The following is a concrete example to illustrate this. Suppose that in a certain dynamic simulation, the initial weighting coefficients of the instantaneous stress exponent generation unit of the controllable series capacitor compensation device are as follows: =0.3、 =0.3、 =0.2、 =0.2. The weight self-correction unit is set to M=10, the safety threshold is 0.6, and the step size is fixed. =0.02. After the device has been running for a period of time, the weighted self-calibration unit statistically analyzed the historical average values ​​of each normalized component before the 10 most recent overvoltage events. The calculated result is assumed to be: =0.75、 =0.50、 =0.45、 =0.60. Next, the weighted self-calibration unit compares these historical averages with the safety threshold of 0.60.6 and calculates the absolute value of the deviation:

[0116] The absolute value of the deviation: |0.75-0.6|=0.15 |0.75-0.6|=0.15;

[0117] The absolute value of the deviation: |0.50-0.6|=0.10 |0.50-0.6|=0.10;

[0118] The absolute value of the deviation: |0.45-0.6|=0.15 |0.45-0.6|=0.15;

[0119] The absolute value of the deviation: |0.60-0.6|=0.00;

[0120] In this example, and The absolute value of the deviation is 0.15, which is the largest; The absolute value of the deviation is 0.00, which is the minimum. According to the weighting adjustment rules, the component with the largest absolute value of deviation (here we assume that the component with the largest absolute value of deviation is selected first) is chosen. When the calculation results of two normalized components are the same, they can be selected according to the parameter arrangement order. The corresponding weight is increased by Δw, and the component with the smallest absolute value of deviation ( The weight corresponding to ) is reduced by Δw, while the weights of the other components remain unchanged.

[0121] Therefore, the weights are adjusted as follows: An increase of 0.02: 0.3 + 0.02 = 0.32; Remain unchanged: 0.3; Remain unchanged: 0.2; Decrease by 0.02: 0.2 - 0.02 = 0.18;

[0122] After adjustment, the new weighting coefficients are: =0.32、 =0.3、 =0.2、 =0.18. These new weighting coefficients will be used in the subsequent calculation of the instantaneous stress index. In this way, when the peak capacitor voltage continues to deviate from the safety threshold, its weight in the instantaneous stress index will increase accordingly, making the instantaneous stress index more sensitive to the risks brought by the peak capacitor voltage.

[0123] Through the above technical solution, this application enables dynamic adaptive adjustment of the weighting coefficients in the calculation of the instantaneous stress index. This solves the problem that static weights in traditional devices cannot adapt to changes in the dominant stress factors under different operating conditions, significantly improving the accuracy and sensitivity of the instantaneous stress index assessment. Through a weight self-correction mechanism based on historical overvoltage event statistics, the device can more accurately identify the main stress risks under the current operating conditions, avoiding misjudgments or omissions caused by improper weight allocation. This allows the controllable series capacitor compensation dynamic simulation device to more realistically and reliably reflect the actual electrical stress conditions during operation, providing a more accurate basis for the verification of control strategies and the reliability assessment of the device.

[0124] In a preferred embodiment of the present invention, the aging coefficient generation unit calculates the device aging coefficient using the following formula. :

[0125]

[0126] in To accumulate the number of times the signal is activated, The maximum number of times the device can be switched on within its rated lifespan. The current operating temperature. These are reference temperatures, and both are Kelvin temperatures; This represents the temperature acceleration factor coefficient.

[0127] In this embodiment, the aging coefficient generation unit is a functional module within the device, whose core function is to quantify the aging degree of the device based on its operating history and current environmental conditions. This unit can be implemented using dedicated hardware circuitry, such as a microcontroller or digital signal processor, to execute the aforementioned aging coefficient calculation logic.

[0128] Cumulative number of times This refers to the cumulative number of times the thyristor valve group is switched on during the entire operation of the device, which directly reflects the cumulative effect of electrical stress on the device. This parameter can be obtained by monitoring the switching actions of the thyristors in real time and counting them through the data acquisition unit, or by reading the preset counter value in the device's internal memory.

[0129] Maximum number of conduction cycles within the rated lifespan This refers to the maximum number of conduction cycles that a device can withstand during its design lifespan. This is a design parameter given by the manufacturer based on device characteristics and reliability standards. This parameter is usually preset in the memory of the aging factor generation unit when the device leaves the factory, or configured before the device is put into operation.

[0130] Current operating temperature This refers to the real-time operating temperature of the device's internal components or key parts (such as the thyristor junction temperature). This temperature can be measured in real time by a temperature sensor (such as a thermistor, thermocouple, or infrared sensor) installed inside the device, and the measured value is transmitted to the aging coefficient generation unit.

[0131] Reference temperature This refers to the standard temperature used to assess the lifespan of a device, typically the rated operating temperature or a reference temperature provided by the device manufacturer. This parameter is usually a fixed value preset in the aging factor generation unit.

[0132] Temperature acceleration factor coefficient It is a dimensionless coefficient used to characterize the accelerating effect of temperature on the aging rate of a device, and it is related to the device material properties and aging mechanism. This coefficient is usually obtained by fitting experimental data or consulting the device datasheet, and is preset in the aging coefficient generation unit.

[0133] In one specific implementation, the aging coefficient generation unit can be implemented by an embedded controller, such as a microcontroller, which receives the current operating temperature from a temperature sensor (e.g., a PT100 RTD mounted on a thyristor heatsink) via an analog-to-digital converter interface. The signal is received and converted into a digital value. Simultaneously, the microcontroller obtains the cumulative number of on-times via a digital input interface or an internal counter. This number of switching operations of the thyristor is counted in real time by the data acquisition unit. The maximum number of conduction cycles within the rated lifespan. Reference temperature Parameters such as the temperature acceleration factor β can be pre-stored in the microcontroller's non-volatile memory. The microcontroller periodically executes the aforementioned aging factor calculation formula, for example, once per second. During the calculation, the microcontroller utilizes its floating-point unit to efficiently perform exponentiation and multiplication operations. For example, assuming... 10 9 Second-rate, The K value is 298.15 K (25°C), and the β value is 0.1. When detected... 5×10 8Next, when the current operating temperature T is 323.15K (50°C), the microcontroller substitutes these values ​​into the formula for calculation. The final calculated device aging coefficient is... It will be transmitted to the comprehensive evaluation index generation unit via the internal bus.

[0134] Through the above technical solution, this application solves the problem that traditional simulation devices only linearly calculate the remaining lifetime based on the cumulative number of conduction cycles, ignoring the accelerating effect of temperature on the device aging rate. This solution introduces a temperature acceleration factor coefficient, taking into account the impact of the current operating temperature on the aging rate, making the calculation of the aging coefficient more accurately reflect the actual physical process and avoiding overestimation of the device's remaining lifetime under high-temperature conditions. This not only improves the accuracy of device aging assessment and provides more reliable basic parameters for the generation of subsequent comprehensive evaluation indices, but also allows the trigger angle update decision to more fully consider the device's health status, thereby effectively extending the device's service life and improving the overall reliability and operational safety of the controllable series capacitor compensation dynamic simulation device.

[0135] In a preferred embodiment of the present invention, the comprehensive evaluation index generation unit calculates the power grid frequency deviation coefficient according to the following formula. :

[0136]

[0137] in, To measure the power grid frequency, For the rated frequency, The maximum allowable frequency deviation;

[0138] The comprehensive evaluation index is then calculated using the following formula. :

[0139]

[0140] in .

[0141] In this embodiment, the power grid frequency deviation coefficient This coefficient is used to quantify the degree to which the actual operating frequency of the power grid deviates from the rated frequency. It is defined as the normalized value of the deviation between the measured power grid frequency and the rated frequency, reflecting the impact of frequency deviation on the operational risk of the equipment. This coefficient can be calculated using a dedicated frequency measurement module, for example, by performing zero-crossing detection, phase-locked loop technology, or fast Fourier transform analysis on the power grid voltage or current signal to obtain the measured power grid frequency in real time and comparing it with the preset rated frequency.

[0142] Measured power grid frequency This refers to the grid frequency detected in real time during the operation of a controllable series capacitor compensation dynamic simulation device. This frequency changes dynamically, reflecting the actual operating conditions of the power grid. The measured grid frequency can be obtained in various ways, such as sampling the grid voltage or current signal using a high-precision sensor and calculating the frequency using a digital signal processor or microcontroller; or outputting frequency information through a phase-locked loop circuit synchronized with the power grid.

[0143] Rated frequency This refers to the standard frequency upon which the power system is designed and operated, such as 50Hz or 60Hz. It is a preset, stable reference value used to measure deviations from the measured grid frequency. The rated frequency is typically stored as a system parameter in the device's non-volatile memory and loaded during device initialization. The maximum permissible frequency deviation... This refers to the maximum allowable deviation of the grid frequency from the rated frequency under normal operating conditions. Frequency deviations exceeding this range may adversely affect the stable operation of the device. This parameter is a configurable threshold, and its value is typically determined based on the power system's operating procedures, grid specifications, or the device's own design tolerance, and is stored in the device's parameter configuration module.

[0144] Comprehensive evaluation index It is a unified and comprehensive index used to comprehensively assess the overall operational risk of a controllable series capacitor compensation dynamic simulation device. It integrates multiple factors such as instantaneous stress, device aging, and grid frequency deviation, providing a normalized value between 0 and 1, intuitively reflecting the overall risk level currently faced by the device. The calculation of this index is typically performed by the device's internal central processing unit (such as a microcontroller or digital signal processor), which receives input from the instantaneous stress index generation unit, the aging coefficient generation unit, and the frequency deviation coefficient calculation module.

[0145] Power grid frequency deviation coefficient The calculation formula is obtained by calculating the measured power grid frequency. With rated frequency The absolute value of the deviation between them, and its relationship with the maximum allowable frequency deviation. Perform a ratio calculation, and then take the minimum value between that ratio and 1. This calculation method ensures the accuracy of the frequency deviation coefficient. The value range is always between [0,1], effectively avoiding distortion of calculation results caused by extreme frequency deviations, thus ensuring its clear physical meaning—directly reflecting the degree to which the current frequency deviation approaches the danger limit. Comprehensive Evaluation Index The calculation formula for the instantaneous stress index Equipment aging coefficient and grid frequency deviation coefficient To integrate. Among them, and The form of this equation allows aging and frequency deviation to have a multiplicative amplifying effect on instantaneous stress, more realistically reflecting the synergistic effect of multiple risk factors superimposed. The final result is minimized by 1 to ensure a comprehensive evaluation index. Similarly, by maintaining the range of [0,1], a unified and bounded risk quantification indicator can be provided for subsequent control decisions.

[0146] The following is a concrete example to illustrate this. Suppose that at a certain moment, the data acquisition unit collects the measured power grid frequency in real time. The frequency is 49.8Hz. This is the device's preset rated frequency. The maximum permissible frequency deviation is 50Hz. The frequency is 0.5Hz. At this point, the comprehensive evaluation index generation unit first calculates the power grid frequency deviation coefficient. According to the formula Substituting the values, we get δ=min(1, =0.4.

[0147] Furthermore, assuming the instantaneous stress index output by the instantaneous stress index generation unit is... The aging coefficient output by the aging coefficient generation unit is 0.6. The value is 0.2. The comprehensive evaluation index generation unit substitutes these values ​​into the comprehensive evaluation index. The calculation formula is as follows: .

[0148] Substituting the values, we get: In this example, although the instantaneous stress index and device aging coefficient It is not extremely high, but due to a certain deviation in the power grid frequency and the multiplicative fusion mechanism amplifying the impact of various factors, the overall evaluation index ultimately becomes higher. A value of 1 indicates that the overall risk faced by the device has reached its highest level. This provides a clear signal for the subsequent firing angle update unit to adjust the firing angle, indicating that strong intervention measures are needed to reduce the risk.

[0149] Through the above technical solution, this application effectively solves the problems of the original solution not considering the impact of grid frequency deviation on the device's operating status, being unable to quantify the operational risks caused by grid frequency deviation from the rated value, and lacking a unified and reasonable integration rule to integrate multi-dimensional risk factors. Specifically, by introducing a grid frequency deviation coefficient... This solution accurately captures the actual frequency deviation of the power grid and normalizes and quantifies it, thus clearly characterizing the risk level of the frequency deviation. More importantly, this solution employs a product-based fusion rule to integrate the instantaneous stress exponent λ, the device aging coefficient γ, and the power grid frequency deviation coefficient. This approach organically combines factors such as instantaneous stress, device aging, and frequency deviation, fully considering the synergistic amplification effect of these three factors on operational risks. This multiplicative fusion mechanism, compared to simple linear superposition, more accurately reflects the cumulative impact of multiple risk factors in actual operation, enabling the final comprehensive evaluation index Λ to more comprehensively and accurately reflect the actual comprehensive operational risks of the controllable series capacitor compensation dynamic simulation device. Furthermore, by... By limiting the range to [0,1], an intuitive and bounded decision-making basis is provided for subsequent trigger angle adjustments, thereby significantly improving the realism of the device's dynamic simulation, the effectiveness of the control strategy, and the reliability of the device's operation.

[0150] In a preferred embodiment of the present invention, the trigger angle update unit calculates the updated trigger angle using the following formula:

[0151]

[0152] in The current trigger angle. To trigger the corner update value, This represents the maximum permissible change in trigger angle per step. To comprehensively evaluate the reference threshold of the index, , For symbolic functions, For input values, when When the value is greater than 0, the value is 1. When =0, the value is 0. When the value is less than 0, the value is -1.

[0153] In this embodiment, the firing angle update unit is a module within the device responsible for calculating and outputting a new thyristor firing angle based on a specific algorithm and input parameters. Its core function is to dynamically adjust the compensation degree of the controllable series capacitor compensation device to respond to changes in the power grid operating status and the device's own condition. This unit can be implemented by an embedded controller (e.g., a digital signal processor or a field-programmable gate array), which programs the calculation logic of the above formula and outputs control signals to the thyristor drive circuit. Alternatively, it can be implemented through a host computer software platform, where a computer program receives real-time data, performs calculations, and sends the updated firing angle to the lower-level controller via a communication interface.

[0154] Updated trigger angle This refers to the new firing angle value calculated by the firing angle update unit, used to control the thyristor's conduction timing. This value directly affects the equivalent reactance of the controllable series capacitor compensation device. This value can be stored as a digital quantity in the controller's register and transmitted in real time to the thyristor firing pulse generation module, or converted into an analog voltage signal via a digital-to-analog converter to drive the analog control circuit.

[0155] Current trigger angle This refers to the firing angle value that the thyristor was using before the current firing angle update calculation; it serves as the reference point for the firing angle update. This value is typically the firing angle calculated and applied in the previous control cycle and stored in the controller's memory. Alternatively, it can be read in real-time from sensors or feedback loops to determine the actual firing angle of the current thyristor.

[0156] Maximum permissible change in trigger angle per step This refers to the maximum allowable adjustment range of the firing angle within a single control cycle. It is a preset safety parameter used to limit the drastic degree of firing angle adjustment, preventing system instability or device overstress caused by sudden changes in the firing angle. This value can be configured as a system parameter during device initialization and stored in non-volatile memory, or it can be dynamically adjusted via a host computer according to the device's operating mode or the stability requirements of the power grid.

[0157] Comprehensive evaluation index The index is calculated by the comprehensive evaluation index generation unit and passed as an input parameter to the trigger angle update unit. Alternatively, it can be generated by weighted fusion of information such as instantaneous stress, aging, and frequency deviation through a real-time data processing system.

[0158] Comprehensive evaluation index reference threshold This is a preset reference point used to determine whether the operational risk reflected by the comprehensive evaluation index is within an acceptable range, with a value range of [0.2, 0.5]. This threshold can be set according to the device's design specifications and operational experience, and stored in the controller's parameter table. Alternatively, it can be dynamically optimized based on historical operational data and system performance targets using an expert system or adaptive algorithm.

[0159] Sign function It is a mathematical function that returns the sign of a number; in this scheme, it is used to determine the direction of the firing angle adjustment. In digital controllers, the logic of the sign function can be implemented through conditional statements; in analog circuits, a similar function can be achieved through comparator circuits.

[0160] The following is a concrete example to illustrate this. The firing angle update unit can be implemented by a high-performance digital signal processor (DSP). This DSP can periodically (e.g., every other power system cycle) execute the firing angle update algorithm. At the beginning of each cycle, the DSP first reads the current firing angle from its internal memory. Simultaneously, it receives the latest comprehensive evaluation index from the comprehensive evaluation index generation unit. Maximum permissible change in trigger angle per step and comprehensive evaluation index reference threshold These preset parameters can be stored in the DSP's program memory. The DSP then performs the following calculations: First, it calculates... The difference is calculated; then the built-in sign function is called (or implemented through a conditional statement) to obtain the sign of the difference, i.e. Next, , Multiplying the result of the sign function yields the adjustment amount for the firing angle; finally, the adjustment amount is multiplied by... Add them together to get the updated trigger angle. .

[0161] For example, assuming the current trigger angle The maximum allowable change in trigger angle per step is 90 degrees. The comprehensive evaluation index is 5 degrees. The value is 0.8, which is the reference threshold for the comprehensive evaluation index. The value is 0.4. First, calculate:

[0162] Since 0.4 is a positive number, the sign function... The result is 1. The adjustment amount is 5 × 0.8 × 1 = 4 degrees. Updated trigger angle. Spend.

[0163] If the comprehensive evaluation index The value is 0.3, while the comprehensive evaluation index reference threshold is... The value remains at 0.4. First, calculate Λ - Λref = 0.3 - 0.4 = -0.1. Since -0.1 is negative, the result of the sign function sgn(-0.1) is -1. The adjustment is 5 × 0.3 × (-1) = -1.5 degrees. The updated firing angle... =90 + (-1.5) = 88.5 degrees. After the calculation is complete, the DSP will... The value is output to the thyristor trigger pulse generation module, which generates a corresponding trigger pulse based on the new trigger angle value to control the conduction of the thyristor, thereby realizing the dynamic adjustment of the controllable series capacitor compensation device.

[0164] Through the above technical solution, this application can achieve adaptive adjustment of the firing angle, effectively solving the problem in the prior art that the firing angle control cannot be dynamically adjusted according to the actual operating risk of the device. Specifically, this solution integrates multiple key factors such as instantaneous stress, device aging degree, and power grid frequency deviation into a comprehensive evaluation index, and uses this index as a basis to accurately determine the adjustment direction and magnitude of the firing angle. When the device faces a high risk, the firing angle can be adjusted to reduce the risk by a larger margin, thereby quickly responding to and mitigating potential operational threats; when the risk is low, the firing angle can be adjusted more gradually to optimize compensation performance. This multi-dimensional information-coordinated dynamic firing angle adjustment mechanism enables the controllable series capacitor compensation dynamic simulation device to reflect the actual operating characteristics more realistically and accurately, significantly improving the accuracy and reliability of the simulation, avoiding device malfunctions or performance degradation caused by unreasonable firing angle adjustment, thus meeting the need for realistically reflecting the operating characteristics of the device.

[0165] like Figure 2 As shown, a controllable series capacitor compensation dynamic simulation method is applied to any of the above-mentioned devices, including steps S1 to S6.

[0166] In step S1, the system collects in real time the capacitor voltage peak value, voltage change rate, current zero-crossing offset, firing angle change rate, cumulative conduction count, current operating temperature, and grid frequency. The real-time acquisition of these parameters forms the data foundation for the entire dynamic simulation method, and their accuracy directly affects the calculation quality of all subsequent evaluation indicators. Unlike traditional methods that only collect single or a small number of electrical quantities, this method simultaneously considers information from three dimensions: instantaneous electrical stress, device aging status, and grid operating conditions, providing comprehensive input for subsequent multi-dimensional fusion evaluation.

[0167] In step S2, the four original parameters—capacitor voltage peak value, voltage change rate, current zero-crossing offset, and firing angle change rate—are normalized to obtain four normalized basic components: the capacitor voltage peak value component, the voltage change rate component, the current zero-crossing offset component, and the firing angle change rate component. This normalization process employs a truncated normalization method based on a safety threshold or limit value, meaning each component is equal to the ratio of the measured value to the corresponding threshold, and the maximum value does not exceed 1. Through this process, parameters with different physical dimensions are uniformly mapped to the [0,1] interval, making subsequent weighted fusion comparable and additive.

[0168] Step S3 fuses the four normalized basic components to generate an instantaneous stress index. This index quantifies the comprehensive instantaneous electrical stress level experienced by the device at the current moment. The fusion method can employ weighted summation, with each weight coefficient preset according to device design specifications or operational experience, or dynamically adjusted by a subsequent weight self-correction unit. This fusion identifies the cumulative risk when multiple parameters simultaneously approach their limits but none individually exceed them, effectively compensating for the shortcomings of traditional independent threshold judgment mechanisms.

[0169] Step S4 generates a device aging coefficient based on the cumulative number of conduction cycles and the current operating temperature. This coefficient not only considers the cumulative effect of the number of conduction cycles but also introduces a temperature acceleration factor, reflecting the accelerating effect of temperature on the device aging rate in an exponential function form, thereby more realistically depicting the actual lifespan consumption of the device.

[0170] Step S5 obtains the grid frequency deviation coefficient and integrates the instantaneous stress index, the device aging coefficient, and the frequency deviation coefficient to generate a comprehensive evaluation index. This integration preferably employs a multiplicative rule, where the comprehensive evaluation index equals the instantaneous stress index multiplied by (1 + aging coefficient) and then multiplied by (1 + frequency deviation coefficient), and is limited to the range [0,1]. This multiplicative integration method fully reflects the synergistic amplification effect of multiple risk factors, enabling the comprehensive evaluation index to comprehensively and accurately reflect the overall operational risk of the device.

[0171] Finally, step S6 outputs the updated trigger angle based on the comprehensive evaluation index, the maximum permissible change in the trigger angle per step, and the current trigger angle. The update rule is: the current trigger angle plus the maximum permissible change in the trigger angle per step multiplied by the comprehensive evaluation index, and then multiplied by the sign function value of the difference between the comprehensive evaluation index and the reference threshold. This rule ensures that when the comprehensive evaluation index is higher than the reference threshold, the trigger angle is adjusted to increase to reduce the compensation degree, and vice versa, it is adjusted to decrease to improve the compensation efficiency, thus realizing adaptive closed-loop control based on multi-dimensional risk assessment.

[0172] In summary, the dynamic simulation method provided by this invention constructs a complete, multi-information collaborative, controllable series capacitor compensation dynamic simulation and control process through six steps: "acquisition—normalization—instantaneous stress fusion—aging assessment—comprehensive index generation—trigger angle adaptive update," significantly improving the simulation device's ability to reproduce real operating characteristics. The above description is merely a preferred embodiment of this invention and is not intended to limit the invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A controllable series capacitor compensation dynamic simulation device, characterized in that, include: The data acquisition unit is used to collect capacitor voltage peak value, voltage change rate, current zero-crossing offset, firing angle change rate, cumulative conduction count, current operating temperature and grid frequency in real time. The normalization processing unit, connected to the data acquisition unit, is used to normalize the four original parameters: peak capacitor voltage, rate of change of voltage, current zero-crossing offset, and rate of change of firing angle, and outputs the peak capacitor voltage component, rate of change of voltage component, current zero-crossing offset component, and rate of change of firing angle component, respectively. The instantaneous stress index generation unit, connected to the normalization processing unit, is used to fuse the four normalized basic components and output the instantaneous stress index. An aging coefficient generation unit, connected to the data acquisition unit, is used to output the device aging coefficient based on the cumulative number of conductions and the current operating temperature. The comprehensive evaluation index generation unit is connected to the instantaneous stress index generation unit, the aging coefficient generation unit, and the data acquisition unit, respectively. It is used to obtain the power grid frequency deviation coefficient and integrate the instantaneous stress index, the device aging coefficient, and the frequency deviation coefficient to output the comprehensive evaluation index. The trigger angle update unit is connected to the comprehensive evaluation index generation unit and is used to output the updated trigger angle based on the comprehensive evaluation index, the maximum allowable change in trigger angle in a single step, and the current trigger angle.

2. The apparatus according to claim 1, characterized in that, The data acquisition unit includes: Peak normalization subunit, used to calculate the peak normalized component of capacitor voltage. : in This is the measured peak value of the capacitor voltage. This refers to the safe threshold voltage for the capacitor. The rate-of-change normalization sub-unit is used to calculate the voltage rate-of-change components. : in This is the measured value of the capacitor voltage change rate. This represents the device's tolerance limit. Zero-crossing offset normalized sub-unit, used to calculate the current zero-crossing offset component. : in This is the measured absolute value of the current zero-crossing offset. This is the maximum allowed offset; The normalized firing angle rate of change sub-unit is used to calculate the firing angle rate of change components. : in The absolute value of the rate of change of the firing angle is the measured value. The maximum allowable rate of change; the values ​​of each normalized component are all in the range of [0,1].

3. The apparatus according to claim 2, characterized in that, The instantaneous stress index generation unit calculates the instantaneous stress index using the following weighted summation formula. : in The peak weighting coefficient. The rate of change weighting coefficient. The zero-crossing offset weighting coefficient, This is the weighting coefficient for the rate of change of the firing angle. , , as well as All are greater than 0, and .

4. The apparatus according to claim 3, characterized in that, It also includes a weight self-calibration unit, which is connected to the normalization processing unit and the instantaneous stress index generation unit, respectively, and is used to perform real-time self-calibration of the weight coefficients. The weighted self-calibration unit calculates the historical average values ​​of the capacitor voltage peak normalized component, voltage change rate component, current zero-crossing offset component, and firing angle change rate component before the most recent M overvoltage events in each calibration cycle. The weight self-correction unit compares the absolute value of the deviation between the historical average value of each normalized component and the safety threshold. The larger the absolute value of the deviation, the greater the weight. Specifically, the weight of the component with the largest deviation between the historical average value and the safety threshold is increased by a fixed step, the weight of the component with the smallest deviation is decreased by a fixed step, and the weights of the other two components remain unchanged. After adjustment, all weights are greater than 0 and their sum is 1.

5. The apparatus according to claim 3, characterized in that, The aging coefficient generation unit calculates the device aging coefficient using the following formula. : in To accumulate the number of times the signal is activated, The maximum number of times the device can be switched on within its rated lifespan. The current operating temperature. These are reference temperatures, and both are Kelvin temperatures; This represents the temperature acceleration factor coefficient.

6. The apparatus according to claim 5, characterized in that, The comprehensive evaluation index generation unit calculates the power grid frequency deviation coefficient according to the following formula. : in, To measure the power grid frequency, For the rated frequency, The maximum allowable frequency deviation; The comprehensive evaluation index is then calculated using the following formula. : in .

7. The apparatus according to claim 6, characterized in that, The trigger angle update unit calculates the updated trigger angle using the following formula: in The current trigger angle. To trigger the corner update value, This represents the maximum permissible change in trigger angle per step. To comprehensively evaluate the reference threshold of the index, , For symbolic functions, For input values.

8. A controllable series capacitor compensation dynamic simulation method, applied to the device described in any one of claims 1-7, characterized in that, include: S1. Real-time acquisition of capacitor voltage peak value, voltage change rate, current zero-crossing offset, firing angle change rate, cumulative conduction count, current operating temperature and grid frequency; S2. Normalize the four original parameters, namely, peak capacitor voltage, rate of change of voltage, current zero-crossing offset, and rate of change of firing angle, to obtain four normalized basic components, including the peak capacitor voltage component, the rate of change of voltage component, the current zero-crossing offset component, and the rate of change of firing angle component. S3. Fuse the four normalized basic components from step S2 to generate the instantaneous stress index; S4. Generate the device aging coefficient based on the cumulative number of conduction cycles and the current operating temperature; S5. Obtain the power grid frequency deviation coefficient, and integrate the instantaneous stress index, device aging coefficient, and frequency deviation coefficient to generate a comprehensive evaluation index; S6. Based on the comprehensive evaluation index, the maximum allowable change in trigger angle per step, and the current trigger angle, output the updated trigger angle.

Images