Dynamic adjustment method and system for detuning protection constant value of converter station

Abstract

The invention discloses a dynamic adjustment method and system for a detuning protection constant value of a converter station. The method comprises the following steps: capturing full-spectrum harmonic data of a filter switching event through high-speed monitoring; the harmonic amplification factor and the phase change are analyzed on line, and the resonance risk level is evaluated; according to the risk level, adopting a nonlinear adaptive coefficient to dynamically decide and safely check alarm and tripping constant values of detuning protection; and finally issuing a new constant value online for execution. The system correspondingly comprises a data acquisition unit, a monitoring analysis unit, a risk assessment decision unit, a safety check execution unit and the like, harmonic monitoring, risk assessment and protection control are deeply fused, the crossing of a protection constant value from static presetting to dynamic self-adaption is realized, the system has the capability of pre-warning resonance risks in advance, the safe and stable operation of the converter station is ensured, and the safety of the converter station is ensured. And the problem that the fixed value protection is easy to operate by mistake or reject operation due to the harmonic background change during the system switching operation is solved.

Description

Technical Field

[0001] This invention relates to the field of filter protection technology, and in particular to a method and system for dynamically adjusting the setting value of converter station detuning protection. Background Technology

[0002] In high-voltage direct current (HVDC) transmission systems, converter stations typically have numerous filters and parallel capacitors installed on the AC side to filter out characteristic harmonics and provide reactive power compensation. Detuning protection is one of the key protections to ensure the safety of these critical devices. It monitors the harmonic content of the filter branch current to determine whether the equipment has become detuned due to component failure, thereby issuing an alarm or tripping command.

[0003] Currently, detuning protection widely used in engineering typically employs fixed setpoints. These setpoints are calculated offline based on the background harmonic levels, equipment parameters, and safety margins of the system under specific typical operating conditions, and once set, they remain unchanged during operation. However, actual power systems operate in complex and variable ways, especially during filter switching operations, when the system's harmonic impedance network undergoes significant changes, potentially triggering temporary amplification or resonance of specific harmonic orders. This dynamically changing harmonic background can lead to the following problems:

[0004] Misoperation of protection: When switching operations cause a brief but high-amplitude harmonic amplification, the fixed-set detuning protection may misjudge the equipment as detuned because the measured harmonic current exceeds the set value, resulting in unnecessary alarms or tripping and affecting the reliable operation of the system.

[0005] Protection failure to activate: If the fixed setpoint is set too conservatively to avoid the above-mentioned risk of false activation, the protection may not be able to activate sensitively when a slight detuning fault actually occurs in the equipment, which poses a safety hazard.

[0006] While some existing research focuses on harmonic monitoring and protection, it primarily concentrates on locating harmonic sources, assessing harmonic levels, or improving protection algorithms. There is a lack of technical solutions that combine real-time, predictive system resonance risk assessment with a closed-loop dynamic adjustment of protection settings. The contradiction between the static characteristics of protection settings and the dynamic characteristics of system harmonic states has become a potential bottleneck affecting the safe and stable operation of converter stations. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies where the detuning protection setting is fixed and cannot adapt to the dynamic changes of system harmonics, which can easily lead to false tripping or failure to trip, the purpose of this invention is to provide a method and system for dynamically adjusting the detuning protection setting of a converter station. This method and system can sense the harmonic state of the system in real time, assess the resonance risk caused by switching operations, and intelligently and safely adjust the protection setting accordingly, thereby achieving dynamic adjustment of the protection.

[0008] The technical solution adopted by this invention to solve its technical problem is:

[0009] In a first aspect, the present invention provides a method for dynamically adjusting the setting value of detuning protection in a converter station, comprising the following steps:

[0010] S1: Real-time monitoring of AC electrical quantities of the converter station. When a filter switching event is detected, high-speed data acquisition is triggered to obtain electrical quantity data within a set time window before and after the event. The electrical quantity data includes three-phase voltage, three-phase current, zero-sequence component and interharmonic related electrical parameters.

[0011] S2: Based on the electrical quantity data, perform full-spectrum harmonic analysis and calculate the amplification factor of the key harmonic h. Phase change Multiharmonic coupling coefficient and amplification duration Assess the resonance risk level R under the current operating conditions;

[0012] Full-spectrum harmonic analysis was performed using existing harmonic analysis equipment, which will not be elaborated upon here. The key term for harmonics is the target subharmonic.

[0013] S3: Based on the assessed real-time resonance risk level R, the transient / steady-state dual-track alarm setting value of the target detuning protection device is dynamically determined using nonlinear adaptive coefficients. and trip setting The adjustment plan and the mechanism for setting the value back down;

[0014] S4: After the safety verification, protection sensitivity verification, and equipment thermal tolerance verification of the newly determined overvoltage value are all passed, the verification is sent offline to the target detuning protection device for execution; if any verification fails, a graded substitution adjustment strategy is activated.

[0015] Further, in step S2, the amplification factor of the key harmonic h is calculated. With phase change This can be achieved through the following formula:

[0016] ;

[0017] ;

[0018] Among them, the time window is set before the event. After the incident Their lengths are all integer multiples of the system's power frequency period, and ; and These are the time windows preceding the event. The amplitude and phase of the h-th harmonic current measured internally; and Post-event time windows The amplitude and phase of the h-th harmonic current measured internally.

[0019] Furthermore, the multi-harmonic coupling coefficient , , used to characterize the resonance enhancement effect after the superposition of the h-th and k-th harmonics, is calculated using the following formula:

[0020] ;

[0021] ;

[0022] ;

[0023] .

[0024] in, , These are the active power of the h-th and k-th harmonics, respectively; The active power of the coupling between the h-th and k-th harmonics; The closer the value is to 1, the stronger the coupling effect.

[0025] Furthermore, the resonance risk level R is assessed by dividing it into at least four levels, including:

[0026] If for all the h-th harmonics of interest, the following condition is met: And any If so, the risk level R is determined to be Level 1. This indicates no significant risk.

[0027] If any h-th harmonic exists, satisfying ,and or If so, the risk level R is determined to be level two. This indicates a mild risk.

[0028] If any h-th harmonic exists, and simultaneously satisfies and or If so, the risk level R is determined to be level three. This indicates a moderate risk.

[0029] If any h-th harmonic exists, and simultaneously satisfies and or If so, the risk level R is determined to be level four. This indicates a high level of risk.

[0030] in, , and The preset harmonic amplification factor threshold is, and ; This is a preset threshold for phase change. This is the transient / steady-state boundary time.

[0031] Furthermore, in step S3, the nonlinear adaptive coefficient includes a mild risk coefficient. Medium risk coefficient High-risk coefficient The specific calculations are as follows:

[0032] (1) Mild risk coefficient :

[0033] ; ;

[0034] (2) Moderate risk coefficient :

[0035] ; ;

[0036] (3) High risk coefficient :

[0037] ; ;

[0038] in, , , , , , The preset sensitivity coefficient, , , This is the default value.

[0039] Preferred, < < , < < .

[0040] In step S3, the core of the dynamic decision-making adjustment scheme lies in introducing a nonlinear adaptive adjustment coefficient. , , These coefficients represent the risk level R and key parameters. , ,、 The function makes the setpoint adjustment non-linearly related to the risk level, with more aggressive adjustments at higher risks. The decision-making scheme distinguishes between transient and steady-state scenarios: if the harmonic amplification duration... Less than the threshold This is considered a transient process, and a relatively conservative transient adjustment strategy is adopted; if Greater than or equal to This is considered a potential risk of entering steady-state resonance, so a relatively aggressive steady-state adjustment strategy is adopted. Furthermore, the scheme includes a setpoint fallback mechanism; once the risk of harmonic amplification is detected to have disappeared, the setpoint can smoothly recover to the reference level, avoiding long-term deviations.

[0041] Furthermore, the transient / steady-state dual-track setpoint adjustment scheme and setpoint fallback mechanism are as follows:

[0042] (1) Transient setpoints are applicable :

[0043] ;

[0044] ;

[0045] ;

[0046] in, This is the transient adjustment factor;

[0047] (2) Steady-state setpoints are applicable :

[0048] ;

[0049] ;

[0050] (3) Fixed value fallback mechanism:

[0051] When harmonic amplification disappears, that is... Continuing, the steady-state setpoint falls back to the reference value according to the following formula:

[0052] ;

[0053] in, t represents the pullback coefficient, and t represents the current time.

[0054] Furthermore, in step S4, the thermal withstand capability verification of the equipment is achieved by calculating the harmonic equivalent thermal current, and the specific criteria are as follows:

[0055] (1) Calculation of harmonic equivalent thermal current:

[0056] ;

[0057] ;

[0058] in, is the effective value of the fundamental current, and h is the harmonic order weight;

[0059] (2) Heat tolerance test criteria:

[0060] ;

[0061] in, The rated thermal current of the equipment is determined based on the nameplate parameters of the capacitors and reactors.

[0062] (3) Tiered substitution adjustment strategy:

[0063] The trip setting is higher than But no more than 5% The time-limited effective mode is adopted. The trip setting at this moment is temporarily used and the setting is continuously monitored for the set minutes. If it is still not met, the original setting will be restored.

[0064] If the trip setting exceeds the equipment's tolerance limit: Do not adjust it and trigger an operation and maintenance alarm, while also pushing optimization suggestions;

[0065] The thermal tolerance check failed, so the thermal limit constraint setting is activated:

[0066] ;

[0067] in, This is the upper limit of the original trip setting.

[0068] Furthermore, the identification of switching events is achieved by monitoring the position signal changes of circuit breakers or disconnectors, or by detecting step changes in the relevant branch current from zero to positive or vice versa.

[0069] Secondly, the present invention also provides a converter station detuning protection setting dynamic adjustment system for implementing the above method, comprising:

[0070] High-speed synchronous data acquisition unit: used for real-time synchronous acquisition of electrical quantity data on the AC side of the converter station;

[0071] Multi-dimensional harmonic analysis and risk assessment unit: used to perform full-spectrum harmonic analysis, key parameter calculation, online estimation and updating of system harmonic impedance, and resonance risk level assessment by multi-criteria fusion;

[0072] Transient-steady-state coordinated setpoint decision unit: used to generate setpoint adjustment schemes and fallback instructions that distinguish between transient and steady states by calling nonlinear adaptive coefficients based on real-time risk assessment results;

[0073] Full-dimensional safety verification and execution unit: used to automatically verify the decision scheme for overvoltage, sensitivity and heat resistance, and to send the new set value that has passed the verification to the target detuning protection device.

[0074] Compared with the prior art, the beneficial effects of the present invention are:

[0075] This invention transforms the protection setting from a static preset to a dynamic adjustment, enabling real-time response to changes in the system's harmonic background and solving the problem of erroneous or non-operational behavior when using existing fixed settings. Through online harmonic analysis and risk assessment, it achieves early warning and quantitative evaluation of resonance risks, giving the protection system a certain predictive capability. Attached Figure Description

[0076] Figure 1 This is a flowchart illustrating the dynamic adjustment method for converter station detuning protection settings provided in an embodiment of the present invention.

[0077] Figure 2 A flowchart illustrating the dynamic adjustment method for converter station detuning protection settings provided in this embodiment of the invention.

[0078] Figure 3 This is a structural block diagram of the converter station detuning protection setting dynamic adjustment system provided in an embodiment of the present invention.

[0079] Figure 4 This is a schematic diagram of a converter station's detuning alarm when using a fixed setpoint in the existing technology.

[0080] Figure 5 This is a schematic diagram illustrating the dynamic changes in the detuning protection setting after adopting the dynamic adjustment method of the present invention. Detailed Implementation

[0081] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0082] In order to solve the technical problems in the prior art, the present invention will now be further described in conjunction with the accompanying drawings and embodiments:

[0083] like Figures 1 to 3 As shown in the figure, an embodiment of the present invention discloses a method for dynamically adjusting the setting of detuning protection in a converter station, comprising the following steps:

[0084] S1: Real-time monitoring of AC electrical quantities in the converter station. When a filter switching event is detected, high-speed data capture is triggered to obtain electrical quantity data within a set time window before and after the event.

[0085] The electrical quantity data covers three-phase voltage, three-phase current, zero-sequence component, and interharmonic related electrical parameters.

[0086] In a specific embodiment, the identification of switching events can be achieved by monitoring the position signal changes of auxiliary contacts of circuit breakers or disconnectors, or by detecting step changes in the relevant branch current from zero to positive or vice versa using high-speed sampled current signals. The electrical quantity data includes at least three-phase voltage and three-phase current, and preferably also includes a zero-sequence component. The high-speed acquisition sampling frequency should be no less than 10kHz to ensure accurate analysis of higher harmonics. The set time window typically covers several power frequency cycles before the event to dozens of power frequency cycles after the event, used to capture steady-state and transient harmonic characteristics before and after the event.

[0087] S2: Perform full-spectrum harmonic analysis based on electrical quantity data to calculate the amplification factor of the key harmonic h. Phase change Multiharmonic coupling coefficient and amplification duration Assess the resonance risk level R under the current operating conditions;

[0088] In specific embodiments, key parameters characterizing resonance features include, but are not limited to:

[0089] Amplification factor of key harmonic h : Characterizes the increase of a specific harmonic current after switching relative to before switching.

[0090] Phase change : Characterizes the harmonic phase shift caused by switching.

[0091] Multi-harmonic coupling coefficient : Characterizes the enhancing effect of the interaction between different harmonic orders on resonance.

[0092] Amplify duration : Characterizes the duration of harmonic amplification.

[0093] Specifically, the amplification factor of the key harmonic h is calculated. With phase change This is achieved through the following calculation formula:

[0094] ;

[0095] .

[0096] in, and These are the time windows preceding the event. The amplitude and phase of the h-th harmonic current measured internally; and Post-event time windows The amplitude and phase of the h-th harmonic current measured internally.

[0097] Specifically, multi-harmonic coupling coefficient ( The resonance enhancement effect after the superposition of the h-th and k-th harmonics is characterized by the following formula:

[0098] ;

[0099] ;

[0100] ;

[0101] .

[0102] in, , These are the active power of the h-th and k-th harmonics, respectively; The active power of the coupling between the h-th and k-th harmonics; The closer the value is to 1, the stronger the coupling effect.

[0103] , The voltages of the h-th and k-th harmonics are respectively. , The currents are the h-th and k-th harmonics, respectively. , These are the phase differences between the h-th and k-th harmonic voltages and currents, respectively.

[0104] Specifically, amplify the duration The duration of the h-th harmonic amplification state, from the time the harmonic amplitude reaches its maximum value after switching. Start timing.

[0105] The resonance risk level R is assessed in four grades, with the following criteria:

[0106] If for all the h-th harmonics of interest, the following condition is met: And any If so, the risk level R is determined to be Level 1. This indicates no significant risk.

[0107] If any h-th harmonic exists, satisfying ,and or If so, the risk level R is determined to be level two. This indicates a mild risk.

[0108] If any h-th harmonic exists, and simultaneously satisfies and or If so, the risk level R is determined to be level three. This indicates a moderate risk.

[0109] If any h-th harmonic exists, and simultaneously satisfies and or If so, the risk level R is determined to be level four. This indicates a high level of risk.

[0110] in, , and The preset harmonic amplification factor threshold is, and ; This is a preset threshold for phase change. The transient / steady-state boundary time is preset to 5 power frequency cycles.

[0111] S3: Based on the assessed real-time resonance risk level R, the transient / steady-state dual-track alarm setting value of the target detuning protection device is dynamically determined using nonlinear adaptive coefficients. and trip setting The adjustment plan and the mechanism for setting the value back down;

[0112] In a specific embodiment, the core of the dynamic decision-making adjustment scheme lies in introducing a nonlinear adaptive adjustment coefficient. , , These coefficients represent the risk level R and key parameters. , , The function makes the setpoint adjustment non-linearly related to the risk level, with more aggressive adjustments at higher risks. The decision-making scheme distinguishes between transient and steady-state scenarios: if the harmonic amplification duration... Less than the threshold This is considered a transient process, and a relatively conservative transient adjustment strategy is adopted; if Greater than or equal to This is considered a potential risk of entering steady-state resonance, so a relatively aggressive steady-state adjustment strategy is adopted. Furthermore, the scheme includes a setpoint fallback mechanism; once the risk of harmonic amplification is detected to have disappeared, the setpoint can smoothly recover to the reference level, avoiding long-term deviations.

[0113] Specifically, the nonlinear adaptive coefficients include a mild risk coefficient. Medium risk coefficient High-risk coefficient The calculation formula is as follows:

[0114] (1) Mild risk coefficient :

[0115] ;

[0116] Constraints: ; =1.5;

[0117] (2) Moderate risk coefficient :

[0118] ;

[0119] Constraints: ; =2.0;

[0120] (3) High risk coefficient :

[0121] ;

[0122] Constraints: ; =2.5;

[0123] in, =0.2、 =0.15、 =0.3、 =0.25、 =0.4、 =0.3 is the preset sensitivity coefficient.

[0124] Specifically, the transient / steady-state dual-track setpoint adjustment scheme and setpoint fallback mechanism are as follows:

[0125] (1) Transient setpoints are applicable :

[0126] ;

[0127] ;

[0128] ;

[0129] in, =0.1 is the transient adjustment coefficient;

[0130] I alarm-baseThe alarm current value (fixed value) is the original system setting, which is the reference alarm setting. trip-base The reference trip setting is the trip current value (fixed value) set by the original system; I alarm-trans This refers to the transient alarm setpoint, which is the alarm value dynamically adjusted under transient scenarios; I trip-trans This is the transient trip setting, which is the trip value dynamically adjusted under transient scenarios.

[0131] (2) Steady-state setpoints are applicable :

[0132] ;

[0133] ;

[0134] Among them, I alarm-new The steady-state alarm setpoint is the alarm value dynamically adjusted under steady-state conditions; I trip-new This is the steady-state trip setting, which is the trip value dynamically adjusted under steady-state conditions.

[0135] (3) Fixed value fallback mechanism:

[0136] When harmonic amplification disappears, that is... Continuing, the steady-state setpoint falls back to the reference value according to the following formula:

[0137] ;

[0138] in, =0.8 is the pullback coefficient, and t is the current time.

[0139] S4: After the safety verification, protection sensitivity verification, and equipment thermal tolerance verification of the newly determined overvoltage value are all passed, the verification is sent offline to the target detuning protection device for execution; if any verification fails, a graded substitution adjustment strategy is activated.

[0140] In a specific embodiment, the security verification is a key step in ensuring the security of dynamic adjustments, and includes triple verification:

[0141] (1) Overvoltage safety check: Verify that the action behavior corresponding to the new setting will not cause the equipment to be subjected to overvoltage.

[0142] (2) Protection sensitivity verification: Ensure that the protection still has sufficient sensitivity to real equipment detuning faults under the new setting.

[0143] (3) Equipment thermal tolerance check: Calculate the equivalent thermal current flowing through the equipment under the current harmonic background to ensure that it does not exceed the rated thermal current capacity of the equipment. If the check fails, a graded substitution strategy is activated, adopting a time-limited effective mode or activating the set value constrained by the equipment thermal limit.

[0144] Specifically, the thermal withstand capability verification of the equipment is achieved by calculating the harmonic equivalent thermal current, and the criteria are as follows:

[0145] (1) Calculation of harmonic equivalent thermal current:

[0146] ;

[0147] ;

[0148] in, is the effective value of the fundamental current, and h is the harmonic order weight;

[0149] (2) Heat tolerance test criteria:

[0150] ;

[0151] in, The rated thermal current of the equipment is determined based on the nameplate parameters of the capacitors and reactors.

[0152] (3) Tiered substitution adjustment strategy:

[0153] Slight non-compliance will result in a tripping setting slightly higher than the specified value. However, if it does not exceed 5%, a time-limited effective mode will be adopted, and the tripping setting at this moment will be temporarily used and continuously monitored for 10 minutes. If it is still not satisfied, the original setting will be restored.

[0154] If the trip setting is severely exceeded, the trip value will be set far beyond the equipment's tolerance limit: adjustment will be prohibited and an operation and maintenance alarm will be triggered, while optimization suggestions will be pushed.

[0155] The thermal tolerance check failed, so the thermal limit constraint setting is activated:

[0156] ;

[0157] in, This is the upper limit of the original trip setting.

[0158] like Figure 2 As shown, the present invention also provides a converter station detuning protection setting dynamic adjustment system for implementing the above method, comprising:

[0159] High-speed synchronous data acquisition unit: used to acquire AC side electrical quantity data of converter station in real time. The electrical quantity data covers three-phase voltage, three-phase current, zero-sequence component and interharmonic related electrical parameters; it has a filter switching event triggering mechanism, and the triggering methods include monitoring the position signal change of circuit breaker / disconnector or detecting the step change of branch current; it supports high-speed waveform recording with a sampling frequency of not less than 10kHz before and after the event to ensure accurate capture of high-order harmonics and transient characteristics. Its data output terminal is connected to the signal input terminal of the multi-dimensional harmonic analysis and risk assessment unit.

[0160] Multi-dimensional Harmonic Analysis and Risk Assessment Unit: This unit incorporates a harmonic coupling analysis module, a transient component extraction module, and a risk level assessment module. Its signal input receives electrical quantity data transmitted from a high-speed synchronous data acquisition unit, and calculates the amplification factor of the key harmonic h through full-spectrum harmonic analysis. Phase change Multiharmonic coupling coefficient and amplification duration Combined with the above calculation parameters, a level 4 resonance risk assessment is performed, and the output of the risk assessment result is connected to the signal input of the transient-steady-state collaborative setting decision unit.

[0161] Transient-steady-state coordinated setpoint decision unit: It has a built-in nonlinear coefficient calculation module, a dual-track setpoint generation module, and a setpoint fallback module. Its signal input terminal receives the real-time resonance risk level R output by the multi-dimensional harmonic analysis and risk assessment unit, and generates a mild risk coefficient through the nonlinear coefficient calculation module. Medium risk coefficient High risk factor The dual-track setpoint generation module distinguishes between transient and steady-state scenarios and dynamically determines the alarm setpoint of the target detuning protection device. and trip setting The adjustment scheme uses a setpoint fallback module to achieve a smooth setpoint fallback mechanism after the harmonic amplification disappears. The output of the setpoint adjustment scheme is connected to the signal input of the full-dimensional safety verification and execution unit.

[0162] The all-dimensional safety verification and execution unit includes an overvoltage verification module, a protection sensitivity verification module, and a heat tolerance verification module. Its signal input terminal receives the new setting adjustment scheme transmitted by the transient-steady-state collaborative setting decision unit. The three modules are used to perform triple safety verification in sequence. When all three verifications pass, the new setting is sent to the target detuning protection device for execution online through a standard communication protocol. If any verification fails, a graded alternative adjustment strategy is automatically activated.

[0163] This invention also provides a method for dynamically adjusting the setpoint of converter station detuning protection considering resonance risk, and a comparison of the system's effects, for example. Figure 4 , Figure 5 As shown, specifically:

[0164] By collecting and analyzing detuning alarm data from a converter station in Yunnan, the following graphs were drawn: Figure 4 The diagram shown illustrates that using fixed detuning protection values ​​before and after the converter station filter switching will frequently trigger detuning alarms, affecting normal production operations.

[0165] By constructing a converter station simulation model to simulate filter switching conditions, the detuning protection setting diagram after adopting the method and system described in this invention is shown below. Figure 5 As shown in the figure, the dynamic change of the detuning protection value before and after the switching of the converter station filter using the method and system described in this invention is illustrated. Under the premise of ensuring safe and stable operation, the dynamic adjustment of the detuning protection value will not lead to frequent detuning alarms.

[0166] The main functions of this invention are:

[0167] 1. Strong adaptability: The protection setting is changed from static preset to dynamic adjustment, which can respond to changes in the system harmonic background in real time and solve the problem that fixed setting is prone to false activation or failure to activate during system operation.

[0168] 2. Risk Foresight: Through online harmonic analysis and risk assessment, early warning and quantitative assessment of resonance risks are achieved, giving the protection system a certain predictive capability.

[0169] 3. High security: A triple security verification mechanism and a graded substitution strategy are introduced to ensure that every setting adjustment is carried out under strict security constraints, avoiding the introduction of new risks due to improper adjustment.

[0170] 4. High level of intelligence: It adopts nonlinear adaptive coefficients, transient / steady-state dual-track decision-making, and intelligent setpoint fallback strategy, making the adjustment process more in line with physical reality and the decision-making more intelligent.

[0171] In summary, after reading this invention document, those skilled in the art can make various other corresponding modifications to the technical solutions and concepts based on this invention without creative mental effort, and all of these modifications fall within the scope of protection of this invention.

Claims

1. A method for dynamically adjusting the setting value of converter station detuning protection, characterized in that, include: S1: Real-time monitoring of AC electrical quantities in the converter station; when a filter switching event is detected, electrical quantity data within a set time window before and after the event is obtained. S2: Perform spectral harmonic analysis based on electrical quantity data to calculate the amplification factor of the key harmonic h. Phase change Multi-harmonic coupling coefficient and amplification duration Assess the resonance risk level R under the current operating conditions; S3: Based on the assessed real-time resonance risk level R, the transient / steady-state dual-track alarm setting value of the target detuning protection device is dynamically determined using nonlinear adaptive coefficients. and trip setting The adjustment plan and the mechanism for setting the value back down; S4: After the safety verification of the newly determined overvoltage, the protection sensitivity verification, and the equipment thermal tolerance verification are all passed, the result is sent to the target detuning protection device for execution; if any verification fails, a graded substitution adjustment strategy is activated.

2. The method for dynamically adjusting the setpoint of converter station detuning protection according to claim 1, characterized in that, In step S2, the amplification factor of the key harmonic h is calculated. With phase change This can be achieved through the following formula: ； ； Among them, the time window is set before the event. After the incident Their lengths are all integer multiples of the system's power frequency period, and ; and These are the time windows preceding the event. The amplitude and phase of the h-th harmonic current measured internally; and These are the post-event time windows. The amplitude and phase of the h-th harmonic current measured internally.

3. The method for dynamically adjusting the setpoint of converter station detuning protection according to claim 1, characterized in that, The multiharmonic coupling coefficient , , used to characterize the resonance enhancement effect after the superposition of the h-th and k-th harmonics, is calculated using the following formula: ； ； ； ； in, , These are the active power of the h-th and k-th harmonics, respectively; The active power of the coupling between the h-th and k-th harmonics; The closer the value is to 1, the stronger the coupling effect.

4. The method for dynamically adjusting the setpoint of converter station detuning protection according to claim 3, characterized in that, The resonance risk level R is assessed by classifying it into at least four levels, including: If for all the h-th harmonics of interest, the following condition is met: And any If so, the risk level R is determined to be Level 1. This indicates no significant risk. If any h-th harmonic exists, satisfying ,and or If so, the risk level R is determined to be level two. This indicates a mild risk. If any h-th harmonic exists, and simultaneously satisfies and or If so, the risk level R is determined to be level three. This indicates a moderate risk. If any h-th harmonic exists, and simultaneously satisfies and or If so, the risk level R is determined to be level four. This indicates a high level of risk. in, , and The preset harmonic amplification factor threshold is, and ; This is a preset threshold for phase change. This is the transient / steady-state boundary time.

5. The method for dynamically adjusting the setpoint of converter station detuning protection according to claim 4, characterized in that, In step S3, the nonlinear adaptive coefficient includes a mild risk coefficient. Medium risk coefficient High-risk coefficient The specific calculations are as follows: (1) Mild risk coefficient : ； ； (2) Moderate risk coefficient : ； ； (3) High risk coefficient : ； ； in, , , , , , The preset sensitivity coefficient, , , This is the default value.

6. The method for dynamically adjusting the setpoint of converter station detuning protection according to claim 4, characterized in that, The transient / steady-state dual-track setpoint adjustment scheme and setpoint fallback mechanism are as follows: (1) Transient setpoints are applicable : ； ； ； in, This is the transient adjustment factor; (2) Steady-state setpoints are applicable : ； ； (3) Fixed value fallback mechanism: When harmonic amplification disappears, that is... Continuing, the steady-state setpoint falls back to the reference value according to the following formula: ； in, t represents the pullback coefficient, and t represents the current time.

7. The method for dynamically adjusting the setpoint of converter station detuning protection according to claim 6, characterized in that, In step S4, the thermal withstand capability verification of the equipment is achieved by calculating the harmonic equivalent thermal current, and the specific criteria are as follows: (1) Calculation of harmonic equivalent thermal current: ； ； in, is the effective value of the fundamental current, and h is the harmonic order weight; (2) Heat tolerance test criteria: ； in, The rated thermal current of the equipment is determined based on the nameplate parameters of the capacitors and reactors. (3) Tiered substitution adjustment strategy: The trip setting is higher than But no more than 5% The time-limited effective mode is adopted. The trip setting at this moment is temporarily used and the setting is continuously monitored for the set minutes. If it is still not met, the original setting will be restored. If the trip setting exceeds the equipment's tolerance limit: Do not adjust it and trigger an operation and maintenance alarm, while also pushing optimization suggestions; The thermal tolerance check failed, so the thermal limit constraint setting is activated: ； in, This is the upper limit of the original trip setting.

8. The method for dynamically adjusting the setpoint of converter station detuning protection according to claim 1, characterized in that, Identifying switching events is achieved by monitoring changes in the position signals of circuit breakers or disconnectors, or by detecting step changes in the relevant branch current from zero to positive or vice versa.

9. The method for dynamically adjusting the setpoint of converter station detuning protection according to claim 1, characterized in that, The amplification duration The duration of the h-th harmonic amplification state, from the time the harmonic amplitude reaches its maximum value after switching. Start timing.

10. A converter station detuning protection setting dynamic adjustment system for implementing the method of any one of claims 1 to 9, characterized in that, include: High-speed synchronous data acquisition unit: used for synchronous acquisition of electrical quantities such as AC bus voltage and filter branch current of converter station; Multi-dimensional harmonic analysis and risk assessment unit: used to perform spectral harmonic analysis, key parameter calculation, online estimation and updating of system harmonic impedance, and resonance risk level assessment based on multi-criteria fusion; Transient-steady-state coordinated setpoint decision unit: used to generate setpoint adjustment schemes and fallback instructions that distinguish between transient and steady states by calling nonlinear adaptive coefficients based on real-time risk assessment results; Full-dimensional safety verification and execution unit: used to automatically verify the decision scheme for overvoltage, sensitivity and heat resistance, and to send the new set value that has passed the verification to the target detuning protection device.

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