Phase change detection method, storage medium and equipment

Abstract

The invention relates to the technical field of electric power, and discloses a commutation detection method, a storage medium and equipment, and the method comprises the steps: achieving the dynamic dual-feature extraction and quantitative characterization of an exit valve failure index and a conduction valve stress index in a commutation process through the collaborative analysis of dual-valve current signals, and obtaining a commutation result through the geometric constraint characteristics of a preset ellipse criterion equation; according to the method, commutation state judgment is converted into judgment of the geometrical relationship between the criterion value and the threshold boundary, the reliability and robustness of commutation state judgment are effectively improved while the detection rapidity is kept, seamless monitoring and accurate evaluation of the commutation process are achieved, and the detection accuracy is improved. The technical problems of detection delay, false alarm and missing alarm and insufficient anti-interference capability in the prior art are solved, and key technical support is provided for stable operation of a high-voltage direct-current power transmission system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric power, in particular to a commutation detection method, a storage medium and equipment. BACKGROUND

[0002] In a high-voltage direct current (HVDC) transmission system based on a line commutated converter (LCC), the commutation process of a six-pulse converter is a key link for the smooth transition of direct current from a turn-off valve to a turn-on valve, and the driving force comes from the alternating current (AC) line voltage between the two valves. An ideal commutation process requires that the turn-off valve current smoothly decays from the rated value to zero, while the turn-on valve current synchronously rises to the rated value, so as to realize seamless handover of the direct current.

[0003] However, the existing commutation detection technology has inherent defects. The actual measurement type method judges the commutation state by measuring the arc extinction angle γ, but the measurement cannot be completed until the end of the commutation window period, resulting in detection delay. The prediction type method predicts commutation failure by monitoring the AC commutation voltage, but the reliability is restricted by multiple factors, and not all voltage drops will lead to commutation failure, which is prone to false positives or false negatives. The characteristic type method based on a single electrical quantity judges by monitoring the direct current rate of change or single-valve current waveform, which is direct but has poor robustness, and the threshold is difficult to set and is easily affected by measurement noise and transient disturbances. The above methods are difficult to balance between detection speed, reliability and robustness, resulting in technical bottlenecks such as lagging state judgment, misjudgment risk and insufficient anti-interference ability. SUMMARY

[0004] Therefore, it is necessary to propose a commutation detection method, a storage medium and equipment to effectively improve the reliability and robustness of the commutation state judgment while maintaining the detection speed, realize seamless monitoring and accurate evaluation of the commutation process, solve the technical problems of detection delay, false positives and false negatives and insufficient anti-interference ability in the prior art, and provide key technical support for stable operation of the HVDC transmission system.

[0005] To achieve the above purpose, in a first aspect, the present application provides a commutation detection method, which comprises: obtaining a turn-off valve current signal and a turn-on valve current signal of a current to-be-detected commutation event; determining a turn-off valve failure index and a turn-on valve stress index of the current to-be-detected commutation event according to the turn-off valve current signal and the turn-on valve current signal of the current to-be-detected commutation event; substituting the turn-off valve failure index and the turn-on valve stress index of the current to-be-detected commutation event into a preset elliptic criterion equation to obtain an elliptic criterion value; determining a commutation detection result of the current to-be-detected commutation event according to the elliptic criterion value.

[0006] Optionally, the method further comprises: determining a minimum current value in the exit valve current signal of the current commutation event, and a rebound current value at an interval of a first preset time length after the time corresponding to the minimum current value, and determining the exit valve failure index of the current commutation event according to the minimum current value and the rebound current value in the exit valve current signal of the current commutation event; determining current values at all time instants within a second preset time length after the commutation start time in the on valve current signal of the current commutation event, and determining the on valve stress index of the current commutation event according to the current values at all time instants within the second preset time length.

[0007] Optionally, the exit valve failure index of the current commutation event is determined by using the following formula: ; wherein, is the exit valve failure index of the current commutation event, is the time corresponding to the minimum current value in the exit valve current signal of the current commutation event, is the first preset time length, and is the minimum current value in the exit valve current signal of the current commutation event, is the rebound current value in the exit valve current signal of the current commutation event. Optionally, the on valve stress index of the current commutation event is determined by using the following formula:

[0008] ; wherein, is the on valve stress index of the current commutation event, is a maximum function, is a derivative of the current value at the t-th time instant with respect to the t-th time instant, is the commutation start time, is the second preset time length.

[0009] Optionally, the method further comprises: obtaining exit valve current signals and on valve current signals of various historical commutation events, wherein the various historical commutation events include various normal operation conditions; ​​determining, according to the exit valve current signal and the conduction valve current signal of each historical commutation event, an exit valve failure index and a conduction valve stress index of each historical commutation event; determining, according to the exit valve failure index of each historical commutation event, a failure index mean and a failure index standard deviation, and determining, according to the conduction valve stress index of each historical commutation event, a stress index mean and a stress index standard deviation; determining, according to the failure index mean, the failure index standard deviation, the stress index mean and the stress index standard deviation, an elliptical criterion parameter; constructing a preset elliptical criterion equation according to the elliptical criterion parameter.

[0010] Optionally, the elliptical criterion parameter includes a center abscissa, a center ordinate, a major semi-axis and a minor semi-axis of an ellipse, and the determining, according to the failure index mean, the failure index standard deviation, the stress index mean and the stress index standard deviation, an elliptical criterion parameter includes: taking the failure index mean as the center abscissa of the ellipse; taking the stress index mean as the center ordinate of the ellipse; taking a product between the failure index standard deviation and an exit valve sensitivity coefficient as the major semi-axis of the ellipse; taking a product between the stress index standard deviation and a conduction valve sensitivity coefficient as the minor semi-axis of the ellipse.

[0011] Optionally, the preset elliptical criterion equation is ; wherein, is the center abscissa of the ellipse in the elliptical criterion parameter, is the center ordinate of the ellipse in the elliptical criterion parameter, is the major semi-axis of the ellipse in the elliptical criterion parameter, is the minor semi-axis of the ellipse in the elliptical criterion parameter, is the exit valve failure index, is the conduction valve stress index, is an elliptical criterion value.

[0012] Optionally, the determining, according to the elliptical criterion value, a commutation detection result of the current to-be-tested commutation event includes: determining, in a case where the elliptical criterion value is greater than a criterion threshold, that the commutation detection result of the current to-be-tested commutation event is commutation failure; determining, in a case where the elliptical criterion value is less than or equal to the criterion threshold, that the commutation detection result of the current to-be-tested commutation event is commutation success.

[0013] To achieve the above object, the application provides a commutation detection device in a second aspect, and the device comprises: An acquisition module is configured to acquire an exit valve current signal and a conduction valve current signal of a current commutation event to be detected. A quantization parameter determination module is configured to determine an exit valve failure index and a conduction valve stress index of the current commutation event to be detected according to the exit valve current signal and the conduction valve current signal of the current commutation event to be detected. A substitution calculation module is configured to substitute the exit valve failure index and the conduction valve stress index of the current commutation event to be detected into a preset elliptic criterion equation to obtain an elliptic criterion value. A detection result determination module is configured to determine a commutation detection result of the current commutation event to be detected according to the elliptic criterion value.

[0014] To achieve the above object, the application provides a computer readable storage medium storing a computer program, and the computer program is configured to enable a processor to execute the commutation detection method according to any one of the first aspect when the computer program is executed by the processor.

[0015] To achieve the above object, the application provides a computer device comprising a memory and a processor, and the memory stores a computer program, and the computer program is configured to enable the processor to execute the commutation detection method according to any one of the first aspect when the computer program is executed by the processor.

[0016] The application has the following beneficial effects: the above method acquires an exit valve current signal and a conduction valve current signal of a current commutation event to be detected, then determines an exit valve failure index and a conduction valve stress index of the current commutation event to be detected according to the exit valve current signal and the conduction valve current signal of the current commutation event to be detected, substitutes the exit valve failure index and the conduction valve stress index of the current commutation event to be detected into a preset elliptic criterion equation to obtain an elliptic criterion value, and finally determines a commutation detection result of the current commutation event to be detected according to the elliptic criterion value; that is, the dynamic double-feature extraction and quantitative characterization of the exit valve failure index and the conduction valve stress index in the commutation process are realized through the cooperative analysis of the double-valve current signals, the commutation state judgment is converted into the geometric relationship judgment of the criterion value and the threshold boundary by using the geometric constraint characteristics of the preset elliptic criterion equation, the reliability and robustness of the commutation state judgment are effectively improved while maintaining the detection rapidity, the seamless monitoring and accurate evaluation of the commutation process are realized, the technical difficulties of the detection delay, false alarm and missed alarm and insufficient anti-interference capability in the prior art are solved, and key technical support is provided for the stable operation of the high-voltage direct current transmission system. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

[0018] Wherein: Figure 1 It is a schematic diagram of a commutation detection method in an embodiment of the present application. Figure 2 It is a schematic diagram of a commutation detection device in an embodiment of the present application. Figure 3 It is an internal structure diagram of a computer device in some embodiments. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only show some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of the present application.

[0020] In a high-voltage direct-current transmission system based on a line-commutated converter, the commutation process of a six-pulse commutation bridge is a key link for the smooth transfer of direct-current from an exit valve to a conducting valve, and the driving force comes from the alternating-current line voltage between the corresponding phases of the two valves. The ideal commutation process requires that the exit valve current smoothly decays from the rated value to zero, while the conducting valve current synchronously rises to the rated value, realizing seamless handover of the direct-current.

[0021] However, the existing commutation detection technology has inherent defects: the actual measurement type method judges the commutation state by measuring the arc extinction angle γ, but the measurement cannot be completed until the end of the commutation window period, resulting in detection delay; the prediction type method predicts commutation failure by monitoring the abnormality of the alternating-current commutation voltage, but the reliability is restricted by many factors, and not all voltage drops will lead to commutation failure, which is prone to false positives or false negatives; the characteristic type method based on a single electrical quantity judges by monitoring the change rate of the direct-current or the transient characteristics such as the single-valve current waveform, which is direct but has poor robustness, the threshold is difficult to set and is easily affected by measurement noise and transient disturbances. The above methods are difficult to balance between detection speed, reliability and robustness, resulting in technical bottlenecks such as lagging state judgment, misjudgment risk and insufficient anti-interference ability.

[0022] To solve the above problems, the application provides a commutation detection method, a storage medium and equipment, which can effectively improve the reliability and robustness of commutation state judgment while maintaining detection rapidity, realize seamless monitoring and accurate evaluation of the commutation process, solve the technical problems of detection delay, false positives and negatives and insufficient anti-interference ability in the prior art, provide key technical support for stable operation of a high-voltage direct current transmission system, and the specific implementation principle will be described in detail in the embodiments.

[0023] In a first aspect, the application provides a commutation detection method.

[0024] Please refer to Figure 1 , which is a schematic diagram of a commutation detection method in the embodiments of the application, and the method comprises the following steps: Step 110: obtaining the exit valve current signal and the conduction valve current signal of a current commutation event to be detected.

[0025] The current commutation event to be detected refers to a commutation event between the exit valve and the conduction valve during the current commutation process, and the commutation event needs to be detected whether it fails or succeeds.

[0026] For the acquisition method of the valve current signal, in some embodiments, the current signals of the exit valve and the conduction valve corresponding to the commutation event can be synchronously collected when the commutation event occurs, so as to obtain the exit valve current signal and the conduction valve current signal of the current commutation event to be detected.

[0027] It should be noted that the occurrence of the commutation event is essentially an interaction between the exit valve and the conduction valve, and therefore, detecting whether the commutation fails or succeeds is not an isolated behavior of the exit valve. When the commutation fails, the current signals of both the exit valve and the conduction valve will leave corresponding distortion marks. In this regard, the application detects the commutation by synchronously collecting the current signals of the exit valve and the conduction valve corresponding to the commutation event, which can improve the reliability and robustness of detection compared with the existing commutation detection method.

[0028] It should be further noted that since the application detects the commutation by synchronously collecting the current signals of the exit valve and the conduction valve corresponding to the commutation event, the joint analysis mechanism of the double-valve current signals naturally has common-mode noise suppression capability and higher recognition, and therefore, even if one of the valve current signals is disturbed by noise or slight disturbance, the reliability and robustness of detection can be ensured.

[0029] Step 120: determining the exit valve failure index and the conduction valve stress index of the current commutation event to be detected according to the exit valve current signal and the conduction valve current signal of the current commutation event to be detected.

[0030] It should be noted that, for the exit valve, if the commutation fails when the exit valve is exiting, the exit valve current signal will have a current rebound at the exit time, and the rebound current is equivalent to applying a reverse electromotive force in the commutation loop, which will hinder the rise of the conducting valve current signal. Therefore, for the conducting valve, if the commutation fails when the conducting valve is conducting, the current of the conducting valve current signal at the conducting time will be hindered.

[0031] According to the above principle, in some embodiments, the exit valve failure index of the current commutation event to be tested can be determined according to the current value of the exit valve current signal at the exit time of the current commutation event to be tested, and the conducting valve stress index of the current commutation event to be tested can be determined according to the current value of the conducting valve current signal at the conducting time of the current commutation event to be tested.

[0032] Step 130: Substitute the exit valve failure index and the conducting valve stress index of the current commutation event to be tested into the preset elliptical criterion equation to obtain an elliptical criterion value.

[0033] The preset elliptical criterion equation can be obtained and preset by the operator according to a large amount of experience, experiments or statistics, and of course, can be preset by the operator according to actual needs.

[0034] For the determination method of the preset elliptical criterion equation, in some embodiments, the exit valve current signals and the conducting valve current signals of various historical commutation events can be obtained, and then the exit valve failure index and the conducting valve stress index of each historical commutation event can be determined. The exit valve failure index and the conducting valve stress index of various historical commutation events are analyzed by elliptical fitting to obtain various fixed parameters of the ellipse, and then the various fixed parameters of the ellipse are substituted into the elliptical equation to obtain the preset elliptical criterion equation; wherein the various historical commutation events include various normal operating conditions (i.e. non-commutation failure conditions), and the various fixed parameters include the center horizontal coordinate, the center vertical coordinate, the long semi-axis and the short semi-axis of the ellipse.

[0035] Step 140: Determine the commutation detection result of the current commutation event to be tested according to the elliptical criterion value.

[0036] It should be noted that, since the preset elliptical criterion equation is determined in advance according to the exit valve current signals and the conducting valve current signals of various normal operating conditions, the preset elliptical criterion equation is equivalent to a ellipse that geometrically constrains all commutation detection results to be commutation success. When the commutation detection result is commutation failure, the point corresponding to the exit valve failure index and the conducting valve stress index should fall outside the ellipse, and when the commutation detection result is commutation success, the point corresponding to the exit valve failure index and the conducting valve stress index should fall on or inside the ellipse.

[0037] According to the above principle, in some embodiments, the commutation detection result of the current commutation event to be detected can be determined according to a comparison result of the ellipse criterion value and a preset threshold value; the preset threshold value can be obtained by an operator according to a large amount of experience, experiment or statistics and set in advance, and of course, can also be set in advance by the operator according to actual needs.

[0038] In the embodiments of the present application, through the cooperative analysis of the double-valve current signals, dynamic double-feature extraction and quantitative characterization of the exit valve failure index in the commutation process and the stress index of the conducting valve are realized, the commutation state judgment is converted into the geometric relationship judgment of the criterion value and the threshold value boundary by using the geometric constraint characteristics of the preset ellipse criterion equation, the reliability and robustness of the commutation state judgment are effectively improved while maintaining the detection rapidity, seamless monitoring and accurate evaluation of the commutation process are realized, and the technical difficulties of detection delay, false alarm and missing alarm and insufficient anti-interference ability in the prior art are solved, thereby providing key technical support for the stable operation of the high-voltage direct current transmission system.

[0039] In addition, in addition to the above-mentioned problems of maintaining detection rapidity while improving reliability and robustness, realizing seamless monitoring and accurate evaluation, and solving detection delay, the commutation detection method also has the following beneficial effects: reducing the loss caused by misjudgment: the existing detection method has the problems of false alarm or missing alarm, which may cause unnecessary operation of the operation and maintenance personnel or miss the real fault, increase the operation and maintenance cost, the method of the present application improves the accuracy of detection, reduces the misjudgment, avoids invalid maintenance due to misjudgment or equipment damage expansion due to missing judgment, thereby reducing the operation and maintenance cost; adapting to complex working conditions: the method is based on the joint analysis of double-valve current signals and has stronger anti-interference ability, can adapt to various complex operating conditions in the high-voltage direct current transmission system, and can accurately judge the commutation state under different working conditions to ensure the normal operation of the system; providing data support: the method will accumulate a large amount of commutation process data during operation, which can provide rich materials for subsequent research and analysis, and help to deeply understand the characteristics and rules of the commutation process in the high-voltage direct current transmission system, and provide data support for further optimization of commutation detection technology and related control strategies; promoting industry progress: the commutation detection method proposed in the present application provides a new technical idea and solution for the high-voltage direct current transmission field, which helps to promote the technical innovation and development in this field, promotes the progress of the entire industry in the commutation detection technology, and improves the international competitiveness of China in the field of high-voltage direct current transmission technology.

[0040] In a possible implementation, the step 120 in the above embodiment includes: determining a minimum current value in the exit valve current signal of the current commutation event to be tested, and a rebound current value at an interval of a first preset time length after the time point corresponding to the minimum current value, and determining the exit valve failure index of the current commutation event to be tested according to the minimum current value and the rebound current value in the exit valve current signal of the current commutation event to be tested; determining current values at all time points within a second preset time length after the commutation start time point in the conduction valve current signal of the current commutation event to be tested, and determining the conduction valve stress index of the current commutation event to be tested according to the current values at all time points within the second preset time length.

[0041] The first preset time length and the second preset time length can be set by an operator according to a large amount of experience, experiments or statistics, or can be set by the operator according to actual needs.

[0042] For the values of the first preset time length and the second preset time length, in some embodiments, the first preset time length and the second preset time length are preferably set as an extremely short time window, for example, the first preset time length and the second preset time length are both set as 20 milliseconds.

[0043] In the embodiments of the present application, the exit valve current extreme value and the rebound characteristic and the conduction valve current dynamic process characteristic are accurately captured, the quantization accuracy of the failure index and the stress index is improved, reliable input is provided for the ellipse criterion, and the detection robustness is enhanced.

[0044] It can be understood that the method accurately quantizes the current rebound characteristics of the exit valve at the commutation failure time by determining the minimum current value in the exit valve current signal and the rebound current value at an interval of a first preset time length, effectively reflects the hindering effect of the reverse electromotive force of the commutation loop, and simultaneously, the dynamic process characteristic of the conduction valve current being blocked is comprehensively captured by analyzing the current values at all time points within a second preset time length after the commutation start time in the conduction valve current signal. The fine feature extraction of the double-valve current signals not only avoids the difficulty of single electrical quantity threshold setting, but also suppresses common-mode noise interference through joint analysis of the double features, ensures the accurate calculation of the failure index and the stress index, and finally provides high-reliability input parameters for the ellipse criterion equation, so that the commutation state judgment can be quickly and accurately determined based on geometric constraints, and the anti-interference ability and the misjudgment suppression ability of the detection system in complex working conditions are significantly improved.

[0045] In a possible implementation, the exit valve failure index of the current commutation event to be tested is determined by using the following formula: ; wherein, is an exit valve failure index of a current commutation event to be tested, is a time point corresponding to a minimum current value in an exit valve current signal of the current commutation event to be tested, is a first preset time length, when , is a minimum current value in an exit valve current signal of the current commutation event to be tested, when , is a rebound current value in an exit valve current signal of the current commutation event to be tested.

[0046] In the embodiments of the present application, the failure index is accurately constructed by integrating and quantizing the exit valve current extreme value and the rebound feature, and the sensitivity and reliability of the commutation failure detection are significantly improved.

[0047] It can be understood that the method uses integral operation to globally quantify the current change of the exit valve current within the first preset time length after the minimum value time point, which not only captures the static feature of the minimum current value, but also integrates the dynamic evolution process of the rebound current. Compared with the traditional method of using only a single time point current value, the integral processing can effectively filter out transient noise interference, while completely retaining the amplitude and duration information of the current rebound. This quantization method enables the exit valve failure index to accurately reflect the cumulative hindering effect of the back electromotive force when the commutation fails. When the commutation is normal, the integral value tends to be zero, while when the commutation fails, the integral value significantly increases, forming a clear fault discrimination threshold. By converting the time domain feature of the current into a scalar index with physical meaning, the method provides a high-discrimination input parameter for the ellipse criterion, and fundamentally enhances the robustness of the commutation state judgment.

[0048] In a feasible implementation manner, the conduction valve stress index of the current commutation event to be tested is determined by using the following formula: ; wherein, is a conduction valve stress index of a current commutation event to be tested, is a maximum function, is a derivative of a current value at the t time point with respect to the t time point within a second preset time length, is a commutation start time point, is a second preset time length.

[0049] In the embodiments of the present application, the maximum instantaneous current change rate in the dynamic process of the conduction valve current is captured, the current blocking characteristic of the conduction valve when the commutation fails is accurately quantized, and the sensitivity and reliability of the commutation state judgment are enhanced.

[0050] It can be understood that, compared with the traditional method which only relies on the current value or average value at a single moment, the scheme can more sensitively reflect the dynamic characteristics of the conduction valve current hindered by the reverse electromotive force when the commutation fails by capturing the maximum change rate in the current rising process. When the commutation is normal, the current rises smoothly, and the instantaneous change rate is small. When the commutation fails, the current is blocked, causing the rising rate to suddenly change, and the maximum instantaneous change rate significantly increases. This quantitative method not only avoids the interference of noise on the static threshold, but also improves the discrimination of fault discrimination by dynamic feature extraction, provides a high-reliability input parameter for the ellipse criterion, and thus realizes more accurate commutation state judgment under complex working conditions.

[0051] In a feasible implementation manner, the method in the above embodiment further includes: obtaining exit valve current signals and conduction valve current signals of various historical commutation events, wherein the various historical commutation events include various normal operation conditions; determining an exit valve failure index and a conduction valve stress index of each historical commutation event according to the exit valve current signal and the conduction valve current signal of each historical commutation event; determining a failure index mean and a failure index standard deviation according to the exit valve failure indexes of the various historical commutation events, and determining a stress index mean and a stress index standard deviation according to the conduction valve stress indexes of the various historical commutation events; determining ellipse criterion parameters according to the failure index mean, the failure index standard deviation, the stress index mean, and the stress index standard deviation; and constructing a preset ellipse criterion equation according to the ellipse criterion parameters.

[0052] The various normal operation conditions refer to various non-commutation failure conditions, and the ellipse criterion parameters refer to various fixed parameters of the ellipse, such as the horizontal coordinate of the center of the ellipse, the vertical coordinate of the center of the ellipse, the major semi-axis, and the minor semi-axis.

[0053] For the construction manner of the preset ellipse criterion equation, in some embodiments, each parameter in the ellipse criterion parameters can be substituted into the ellipse equation, and the constructed preset ellipse criterion equation can be obtained.

[0054] In the embodiments of the present application, the preset ellipse criterion equation is constructed based on historical data, which provides a scientific, accurate, and highly adaptive geometric constraint model for commutation detection, and effectively improves the reliability and accuracy of commutation state judgment.

[0055] It can be understood that the historical commutation event data under various normal operating conditions is acquired, the exit valve and the conducting valve current signals under different conditions are covered, the data is widely representative, and the characteristics of the system under various normal states are fully reflected, then the exit valve failure index and the conducting valve stress index of each historical commutation event are determined according to the current signals, the key features of the commutation process are quantitatively extracted, the distribution law of the feature indexes under the normal operating conditions is grasped from the statistical point of view by calculating the mean value of the failure index, the standard deviation of the failure index, the mean value of the stress index and the standard deviation of the stress index, based on which, the elliptical criterion parameters are determined, and the preset elliptical criterion equation is constructed, which accurately defines the reasonable range of the exit valve failure index and the conducting valve stress index when the commutation is successful in a geometric form, converts the complex commutation state judgment into the geometric relationship judgment of the criterion value and the threshold value boundary, avoids the difficulty of single electrical quantity threshold setting, and can adapt to different conditions, improves the reliability and accuracy of detection, and provides a solid foundation for subsequent commutation detection.

[0056] In a feasible implementation manner, the elliptical criterion parameters in the above embodiment include a central horizontal coordinate, a central vertical coordinate, a long semi-axis and a short semi-axis of the ellipse.

[0057] In the above embodiment, the elliptical criterion parameters are determined according to the mean value of the failure index, the standard deviation of the failure index, the mean value of the stress index and the standard deviation of the stress index, including: taking the mean value of the failure index as the central horizontal coordinate of the ellipse; taking the mean value of the stress index as the central vertical coordinate of the ellipse; taking the product between the standard deviation of the failure index and the exit valve sensitivity coefficient as the long semi-axis of the ellipse; and taking the product between the standard deviation of the stress index and the conducting valve sensitivity coefficient as the short semi-axis of the ellipse.

[0058] The exit valve sensitivity coefficient and the conducting valve sensitivity coefficient can be obtained by an operator according to a large amount of experience, experiment or statistics and pre-set, and of course, can be pre-set by the operator according to actual requirements.

[0059] For the values of the exit valve sensitivity coefficient and the conducting valve sensitivity coefficient, in some embodiments, the exit valve sensitivity coefficient and the conducting valve sensitivity coefficient are both preferably set to be between (3, 6).

[0060] In the embodiments of the present application, the dynamic parameter setting based on the statistical law is used to realize the accurate adaptive constraint of the commutation success boundary of the elliptical criterion equation, and the adaptability and robustness of the detection model to complex conditions are significantly improved.

[0061] It can be understood that the mean center positioning: the mean value of the failure index and the mean value of the stress index are respectively taken as the horizontal and vertical coordinates of the center of the ellipse, which ensures that the geometric center of the criterion equation coincides with the statistical center of the double characteristic indexes under normal operation, and this design naturally adapts the criterion equation to the normal operation characteristics of the system, avoiding the risk of misjudgment caused by center deviation, especially when the working condition fluctuates, the criterion can still maintain the stability of the benchmark; Dynamic semi-axis design: the product of the standard deviation of the failure index and the sensitivity coefficient of the exit valve is taken as the long semi-axis, and the product of the standard deviation of the stress index and the sensitivity coefficient of the conductive valve is taken as the short semi-axis, which realizes the dynamic expansion of the criterion boundary. The standard deviation reflects the dispersion degree of the characteristic index, and the sensitivity coefficient strengthens the coverage ability of the key working condition through experience weighting. For example, when the system noise increases and the standard deviation rises, the semi-axis length automatically expands to include the reasonable fluctuation range, and the introduction of the sensitivity coefficient ensures that the criterion boundary will not be too relaxed in extreme working conditions, so as to balance the anti-interference and detection sensitivity; Adaptive working condition coverage: through the synergistic effect of statistical parameters and empirical coefficients, the elliptical criterion equation can automatically adapt to the change of characteristic distribution under different operating conditions. For example, under light load working condition, the characteristic index fluctuates less, the standard deviation decreases, the criterion boundary is tightened, and the detection accuracy is improved. Under heavy load or initial fault working condition, the standard deviation increases, the boundary is expanded, and the misjudgment caused by sudden change of working condition is avoided. This adaptive mechanism significantly enhances the coverage ability of the detection method to complex working conditions, and provides more reliable guarantee for stable operation of the system.

[0062] In a possible implementation, the preset elliptical criterion equation in the above embodiment is ; wherein, is a horizontal coordinate of a center of the ellipse in the elliptical criterion parameter, is a vertical coordinate of the center of the ellipse in the elliptical criterion parameter, is a long semi-axis of the ellipse in the elliptical criterion parameter, is a short semi-axis of the ellipse in the elliptical criterion parameter, is an exit valve failure index, is a conductive valve stress index, is an elliptical criterion value.

[0063] In the embodiments of the present application, the preset elliptical criterion equation is constructed by a standard elliptical equation, which realizes the geometric precision constraint of commutation state judgment, and significantly improves the adaptability and reliability of the detection system.

[0064] It can be understood that the equation integrates the dynamic characteristics of the exit valve failure index and the on valve stress index in the standard ellipse form, the geometric structure is naturally adapted to the physical characteristics of the commutation process, the center coordinates are positioned by the mean value of the historical data, the criterion reference is highly consistent with the normal operation characteristics of the system, the center deviation misjudgment caused by the working condition fluctuation is avoided, the long semi-axis and the short semi-axis are dynamically expanded by the product of the standard deviation and the sensitivity coefficient, the characteristic fluctuation range during normal operation is included, and the coverage ability for extreme working conditions is strengthened through experience weighting, when the commutation is successful, the double characteristic index points must fall within the ellipse or on the boundary, and when the commutation fails, the points must overflow, such a geometric constraint mechanism converts the complex time domain signal analysis into intuitive spatial position judgment, greatly simplifies the judgment logic, compared with the traditional threshold method, the equation provides double protection through statistical rules and geometric characteristics, so that the detection system can maintain high precision discrimination under complex working conditions, the dynamic semi-axis design effectively suppresses noise interference, significantly improves the robustness, and provides a more reliable commutation state monitoring solution for the high-voltage direct current power transmission system.

[0065] In a feasible implementation manner, the step 140 in the above embodiment includes: determining the commutation detection result of the current commutation event to be detected as commutation failure when the ellipse criterion value is greater than the criterion threshold; and determining the commutation detection result of the current commutation event to be detected as commutation success when the ellipse criterion value is less than or equal to the criterion threshold.

[0066] The criterion threshold can be set in advance by an operator according to a large amount of experience, experiments or statistics, and of course, can be set in advance by the operator according to actual needs.

[0067] For the value of the criterion threshold, in some embodiments, the application preferably sets the criterion threshold to 1.

[0068] In the embodiments of the application, the comparison result of the preset ellipse criterion value and the criterion threshold is used as the judgment basis to realize accurate and rapid determination of the commutation detection result, and the reliability and accuracy of the detection are effectively improved.

[0069] It can be understood that the method uses the comparison result of the preset ellipse criterion value and the criterion threshold as the judgment basis, determines the commutation failure when the criterion value is greater than the threshold, and determines the commutation success when the criterion value is less than or equal to the threshold, such a judgment mechanism based on geometric constraints converts the complex time domain signal analysis into intuitive threshold comparison, avoids the difficulty of single electrical quantity threshold setting in the traditional method, and through the double protection of statistical rules and geometric characteristics, the detection system can maintain high precision discrimination under complex working conditions, compared with the prior art, the scheme significantly reduces the misjudgment risk, and provides a more reliable commutation state monitoring solution for the high-voltage direct current power transmission system.

[0070] The application provides a commutation detection device in a second aspect.

[0071] Please refer to Figure 2 , a schematic diagram of a commutation detection device in an embodiment of the application, the device 210 includes: The acquisition module 211 is configured to acquire the exit valve current signal and the conduction valve current signal of a current commutation event to be detected. The quantification parameter determination module 212 is configured to determine the exit valve failure index and the conduction valve stress index of the current commutation event to be detected according to the exit valve current signal and the conduction valve current signal of the current commutation event to be detected. The substitution calculation module 213 is configured to substitute the exit valve failure index and the conduction valve stress index of the current commutation event to be detected into a preset elliptic criterion equation to obtain an elliptic criterion value. The detection result determination module 214 is configured to determine a commutation detection result of the current commutation event to be detected according to the elliptic criterion value.

[0072] In the embodiments of the application, the related content of the acquisition module 211, the quantification parameter determination module 212, the substitution calculation module 213 and the detection result determination module 214 described above can be referred to the content in the embodiments shown in Figure 1 , which will not be described here.

[0073] It should be noted that the device 210 of the application further includes some other modules, and it can be understood that the method of the application has a one-to-one correspondence with the device 210, and therefore some other modules of the device 210 of the application are the corresponding content of the method of the application in the embodiments described above.

[0074] In the embodiments of the application, through the cooperative analysis of the double valve current signals, the dynamic double-feature extraction and quantification characterization of the exit valve failure index and the conduction valve stress index in the commutation process are realized, the commutation state judgment is converted into the geometric relationship judgment of the criterion value and the threshold boundary by using the geometric constraint characteristics of the preset elliptic criterion equation, the reliability and robustness of the commutation state judgment are effectively improved while maintaining the detection speed, the seamless monitoring and accurate evaluation of the commutation process are realized, and the technical problems of detection delay, false alarm and missing report and insufficient anti-interference ability in the prior art are solved, thereby providing key technical support for the stable operation of the high-voltage direct current transmission system.

[0075] In addition, in addition to the problems of improving reliability and robustness while maintaining detection speed, achieving seamless monitoring and accurate evaluation, solving detection delay and the like mentioned above, the commutation detection device also has the following beneficial effects: reducing the loss caused by misjudgment: the existing detection device has the problems of false positives or false negatives, which may cause unnecessary operation of the operation and maintenance personnel or miss the real fault, increase the operation and maintenance cost, and the device improves the accuracy of detection, reduces the misjudgment, avoids the invalid maintenance caused by misjudgment or the damage expansion of the equipment caused by missed judgment, thereby reducing the operation and maintenance cost; adapt to complex working conditions: the device based on the joint analysis of the double valve current signals has stronger anti-interference ability and can adapt to various complex operating conditions in the high-voltage direct current transmission system, accurately judge the commutation state under different working conditions, and ensure the normal operation of the system; provide data support: the device will accumulate a large amount of commutation process data during operation, which can provide rich materials for subsequent research and analysis, help to deeply understand the characteristics and rules of the commutation process in the high-voltage direct current transmission system, and provide data support for further optimizing the commutation detection technology and related control strategy; promote the progress of the industry: the commutation detection device provided in the application provides a new technical idea and solution for the high-voltage direct current transmission field, which is helpful to promote the technical innovation and development in this field, promote the progress of the entire industry in the commutation detection technology, and improve the international competitiveness of China in the high-voltage direct current transmission technology field.

[0076] The application provides a computer readable storage medium in a third aspect, which stores a computer program. The computer program is executed by a processor to make the processor execute the commutation detection method according to any one of the first aspect.

[0077] The application provides a computer device in a fourth aspect, which includes a memory and a processor. The memory stores a computer program. The computer program is executed by the processor to make the processor execute the commutation detection method according to any one of the first aspect.

[0078] Figure 3 The internal structure diagram of the computer device in some embodiments is shown. The computer device can be a terminal, a server or a gateway. As shown in the figure, the computer device includes a processor, a memory and a network interface connected through a system bus. Figure 3

[0079] The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and can also store a computer program. The computer program is executed by the processor to make the processor implement each step in the above method embodiments. The internal memory can also store a computer program. The computer program is executed by the processor to make the processor execute each step in the above method embodiments. Those skilled in the art can understand that the computer program can be stored in the non-volatile storage medium or the internal memory, or both.​Figure 3 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0080] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer readable storage medium, and when the program is executed, it can include the processes of the above-mentioned embodiments of the method.

[0081] Any reference to memory, storage, database, or other medium used in the embodiments provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0082] The technical features of the above embodiments can be combined in any way. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0083] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A commutation detection method, characterized in that, The method includes: Acquire the exit valve current signal and the on valve current signal of the current commutation event to be tested; Based on the exit valve current signal and the conduction valve current signal of the current commutation event under test, determine the exit valve failure index and the conduction valve stress index of the current commutation event under test. Substitute the failure index of the exit valve and the stress index of the conduction valve of the current commutation event under test into the preset elliptic criterion equation to obtain the elliptic criterion value. Based on the elliptic criterion value, the commutation detection result of the current commutation event to be tested is determined.

2. The method according to claim 1, characterized in that, The step of determining the exit valve failure index and conduction valve stress index of the current commutation event under test based on the exit valve current signal and conduction valve current signal of the current commutation event under test includes: Determine the minimum current value in the exit valve current signal of the current commutation event under test, and the rebound current value after a first preset time interval following the time corresponding to the minimum current value. Based on the minimum current value and the rebound current value in the exit valve current signal of the current commutation event under test, determine the exit valve failure index of the current commutation event under test. Determine the current value of the conduction valve current signal of the current commutation event under test within a second preset time period after the start of commutation, and determine the stress index of the conduction valve of the current commutation event under test based on the current value of the conduction valve within the second preset time period.

3. The commutation detection method according to claim 2, characterized in that, The exit valve failure index of the current commutation event under test is determined using the following formula: ； in, This is the exit valve failure index for the current commutation event under test. This refers to the moment corresponding to the minimum current value in the exit valve current signal of the current commutation event under test. For the first preset duration, in hour, The minimum current value in the exit valve current signal of the current commutation event under test is... hour, The bounce current value is the exit valve current signal of the current commutation event under test.

4. The commutation detection method according to claim 2, characterized in that, The on-valve stress index of the current commutation event under test is determined using the following formula: ； in, The on-valve stress index is the current commutation event under test. To find the maximum value function, Let be the derivative of the current value at time t within the second preset time period with respect to time t. The commutation start time is [the specified time]. This is the second preset duration.

5. The method according to claim 1, characterized in that, The method further includes: Acquire the exit valve current signal and conduction valve current signal of various historical commutation events, including various normal operating conditions; Based on the exit valve current signal and the conduction valve current signal of each historical commutation event, determine the exit valve failure index and the conduction valve stress index of each historical commutation event. Based on the failure index of the exit valve in various historical commutation events, the mean and standard deviation of the failure index are determined; and based on the stress index of the conduction valve in various historical commutation events, the mean and standard deviation of the stress index are determined. The ellipse criterion parameters are determined based on the mean of the failure index, the standard deviation of the failure index, the mean of the stress index, and the standard deviation of the stress index. Based on the ellipse criterion parameters, a preset ellipse criterion equation is constructed.

6. The method according to claim 5, characterized in that, The ellipse criterion parameters include the abscissa of the center of the ellipse, the ordinate of the center, the major semi-axis, and the minor semi-axis. Determining the ellipse criterion parameters based on the mean of the failure index, the standard deviation of the failure index, the mean of the stress index, and the standard deviation of the stress index includes: The mean of the failure index is used as the x-coordinate of the center of the ellipse; The mean stress index is used as the center ordinate of the ellipse; The product of the failure index standard deviation and the exit valve sensitivity coefficient is taken as the major semi-axis of the ellipse; The product of the stress index standard deviation and the sensitivity coefficient of the conduction valve is taken as the minor semi-axis of the ellipse.

7. The commutation detection method according to claim 1, 5, or 6, characterized in that, The preset elliptic criterion equation is: ; in, The x-coordinate of the center of the ellipse in the ellipse criterion parameters. The ordinate of the center of the ellipse in the ellipse criterion parameters is... The semi-major axis of the ellipse in the ellipse criterion parameters is... The minor semi-axis of the ellipse is the parameter in the ellipse criterion. The failure index of the exit valve. For the stress index of the control valve, This is the elliptic criterion value.

8. The commutation detection method according to claim 1, characterized in that, The step of determining the commutation detection result of the current commutation event to be tested based on the elliptic criterion value includes: If the ellipse criterion value is greater than the criterion threshold, the commutation detection result of the current commutation event to be tested is determined to be a commutation failure; If the elliptic criterion value is less than or equal to the criterion threshold, the commutation detection result of the current commutation event to be tested is determined to be a successful commutation.

9. A computer-readable storage medium, characterized in that, The device contains a computer program that, when executed by a processor, causes the processor to perform the commutation detection method as described in any one of claims 1 to 8.

10. A computer device, characterized in that, It includes a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the commutation detection method as described in any one of claims 1 to 8.

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