A method for analyzing waveforms in an electric power system

Abstract

The present invention discloses a method for analyzing waveforms in an electric power system. The present invention relates to the technical field of electric power waveform analysis, and solves the problem of not using waveform optimization to perform correlation optimization on waveforms with different interference conditions. The present invention identifies specific waveform characteristics by analyzing specific waveform changes of the electric power waveform during transmission, and then locks inconsistent partial areas based on abnormal changes in the waveform characteristics. For partial waveforms associated with these partial areas, based on the correlation change characteristics of these partial waveforms, locks whether these partial waveforms are harmonic waveforms. Based on the correlation process of step-by-step analysis, the subsequent correlation confirmation of specific waveform optimization logic is facilitated, and different types of correlation optimization are performed.

Description

Technical Field

[0001] The present invention relates to the technical field of power waveform analysis, and in particular to a method for analyzing waveforms in a power system. Background Art

[0002] In the power system, the most common power waveform is the sine wave, which represents the change of the voltage or current of the alternating current over time. The sine wave is a periodic waveform that repeats in a certain time period. The period refers to the time required for the waveform to repeat once, usually represented by the symbol;

[0003] The application with publication number CN102016607A discloses a method and apparatus for analyzing a waveform signal of an electric power system; obtaining a waveform signal from the electric power system after filtering; identifying one or more segments on the filtered waveform signal, and based on the information content of the identified segments, classifying each segment in the one or more identified segments as corresponding to normal or abnormal conditions occurring in the electric power system.

[0004] In the specific analysis process of the power waveform generated by its power system, it is generally based on the correlated change characteristics of the corresponding power waveform to identify whether the power waveform is abnormal or has related interference, and then trace the source of the interference to avoid such interference. However, this processing method cannot effectively isolate the interference caused by other lines or other external signals. Therefore, after the interference occurs, the original method cannot avoid such interference. Moreover, the original processing method does not use waveform optimization to correlate and optimize the waveforms with different interference conditions, and cannot guarantee the overall quality of the subsequent power waveform. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a method for analyzing waveforms in an electric power system, which solves the problem of performing correlation optimization on waveforms with different interference conditions without using waveform optimization.

[0006] To achieve the above objectives, the present invention is implemented by the following technical solutions: A method for analyzing waveforms in an electric power system, comprising the following steps:

[0007] Step 1: Based on the point where the power waveform occurs in the power system and the power nodes at different subsequent locations, the power waveform is verified in real time to assess whether the power waveform has any associated changes. If there are any associated changes, abnormal calibration is performed. If there are no associated changes, continuous verification is performed. The specific sub-steps are as follows:

[0008] Based on the specific power transmission route, the power waveform generated by the previous power node is compared with the power waveform received by the next power node. The occurrence points are also regarded as a group of power nodes to identify whether the corresponding power waveforms before and after are completely consistent:

[0009] If they are completely consistent, the power waveforms between adjacent power nodes are compared in real time based on the transmission process of the corresponding power waveforms;

[0010] If they are not completely consistent, the area where the power waveform is inconsistent is calibrated abnormally and synchronously calibrated to the power waveform received by the corresponding power node;

[0011] Step 2: Perform waveform analysis on the received power waveform with abnormal calibration, confirm the frequency of part of the waveform in the abnormal area, and then use the power waveform generated by the previous power node associated with this power waveform as the reference waveform to identify whether part of the waveform is harmonic. The specific method is as follows:

[0012] S21, extract part of the waveform in the abnormal area and confirm the frequency: mark part of the waveform in the abnormal area as an abnormal waveform, determine the peak point of the abnormal waveform, mark the time period between adjacent peak points as T1, and use F1=1÷T1 to confirm the associated frequency F1 corresponding to the abnormal waveform. If the abnormal waveform has only one peak point, directly mark the abnormal waveform as a fluctuating waveform;

[0013] S22, based on the calibrated reference waveform, preferentially determine the peak point of the reference waveform, then confirm the time period between the two peak points and calibrate it as T2, and use F2=1÷T2 to confirm the associated frequency F2 corresponding to the reference waveform;

[0014] S23, identifying whether F1 and F2 are in an integer divisibility relationship: F1÷F2=Q, identifying whether Q is an integer, if it is an integer, calibrating the abnormal waveform as a harmonic waveform, if not an integer, calibrating the abnormal waveform as a fluctuating waveform;

[0015] Step three, confirm the association of the time nodes generated by some waveforms, and lock the time characteristics within the reference waveform based on the confirmed association period. Subsequently, perform waveform optimization within the current power node based on this time characteristic. When some waveforms are harmonic waveforms, use filters to perform frequency compensation to optimize the waveform. When some waveforms are not harmonic waveforms, use phase adjustment to optimize the waveform.

[0016] Preferably, in step 3, the specific method of determining the time characteristics of this part of the waveform is:

[0017] Based on the initial moment and the end moment of the partial waveform, the associated period is locked, and the associated period is the time length between the initial moment and the end moment;

[0018] Prioritize the interval between the first group of partial waveforms and the initial moment of the waveform, then determine the interval between the end moment of the current partial waveform and the initial moment of the next partial waveform, and record the intervals between adjacent partial waveforms in association;

[0019] When waveform optimization is performed again, the current power node generates the corresponding transmitted power waveform in real time based on the power waveform received in real time, and transmits it to the next power node. During the generation process, based on the determined associated time periods and interval time periods, and based on the generated initial moment, the power waveform generated in the subsequent associated time periods is optimized: starting from the initial moment, based on the determined first group of interval time periods, the power waveform is optimized, and the optimization duration is the first group of associated time periods. After the optimization is completed, the optimization process is executed again based on the determined second group of interval time periods, and the optimized time difference is the second group of associated time periods. Based on the determined time characteristics, the subsequent optimization processes are confirmed one by one, and optimized step by step.

[0020] Preferably, since this part of the waveform is a harmonic waveform, a filter is used to perform frequency compensation to optimize the waveform:

[0021] Based on the confirmed correlation frequency F1 of the harmonic waveform, the specific number G of peak points in the harmonic waveform is identified, and the occurrence frequency P of the harmonic waveform is locked, and P=G-1;

[0022] The filtering frequency Lv is determined, and Lv=F1×P to obtain Lv, the filtering frequency of the filter is adjusted to Lv, and this filtering frequency is used to perform specific waveform optimization, and associated optimization is performed in the determined optimization process.

[0023] Preferably, for some waveforms that are fluctuating waveforms, phase adjustment is used to optimize the waveform:

[0024] Identify the inconsistent waveform of the fluctuation waveform from step S11, calibrate the inconsistent waveform as the standard waveform, identify the associated distance between different points at the same vertical position based on the specific comparison process of the fluctuation waveform and the standard waveform, and formulate a confirmation method of the associated distance as follows: associated distance = fluctuation waveform point - standard waveform point, the unit length of the distance is formulated in advance by the operator, and based on several groups of associated distances confirmed at different vertical positions, sum up several groups of associated distances, lock the sum value, if the sum value is greater than 0, generate a phase parameter reduction signal, if the sum value is less than 0, generate a phase parameter increase signal, if the sum value = 0, do not make any adjustment;

[0025] When the current power node is executing a specific optimization process, the original phase parameter is gradually changed based on the confirmed phase parameter reduction signal or phase parameter increase signal. Based on the specific step-by-step adjustment process, the correlation distance between the point of the corresponding adjusted optimized fluctuation waveform and the point at the same vertical position in the standard waveform is confirmed in real time. When the correlation distance is ≤Y1, the adjustment is stopped and the adjusted phase parameter is kept unchanged, where Y1 is a preset value. Each subsequent related optimization process adopts the same adjustment method until the correlation distance is ≤Y1. The adjustment is stopped.

[0026] The present invention provides a method for analyzing waveforms in an electric power system. Compared with the prior art, the method has the following beneficial effects:

[0027] The present invention identifies the specific waveform characteristics of the power waveform by analyzing the specific waveform changes during transmission. Subsequently, based on the abnormal changes of the waveform characteristics, the inconsistent partial area is locked. For the partial waveform associated with this partial area, based on the associated change characteristics of this partial waveform, whether this partial waveform is a harmonic waveform is locked. Based on the related process of step-by-step analysis, the related confirmation of the subsequent specific waveform optimization logic is facilitated, and different types of related optimization are performed.

[0028] Based on the different abnormal waveforms appearing in the corresponding power waveform, different optimization processing methods are used to optimize such abnormal waveforms, and based on the time characteristics of the corresponding abnormal waveforms, relevant optimization is performed within a specified time period to ensure the full optimization of the entire power waveform and achieve the best correlation optimization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the process of the present invention;

[0030] Figure 2 It is a schematic diagram for determining the harmonic waveform of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1 , the present application provides a method for analyzing waveforms in an electric power system, comprising the following steps:

[0033] Step 1: Based on the occurrence point of the power waveform in the power system and the power nodes at different subsequent positions, the generated power waveform is verified in real time to assess whether the power waveform has undergone related changes. If there is a related change, abnormal calibration is performed. If there is no related change, continuous verification is performed. Specifically, the occurrence point and the specific power node can be the relevant transformer, substation or switch equipment in the power system. The corresponding power nodes and occurrence points have the relevant functions of monitoring and data processing, and the power waveform can be adjusted in a related manner to avoid the related influence of power fluctuations or harmonics and ensure the normal transportation of the corresponding power.

[0034] The specific sub-steps for assessing whether the power waveform undergoes a correlated change are as follows:

[0035] S11. Based on the specific power transmission route, the power waveform generated by the previous power node is compared with the power waveform received by the next power node. The occurrence points are also regarded as a group of power nodes to identify whether the corresponding power waveforms before and after are completely consistent:

[0036] If they are completely consistent, the power waveforms between adjacent power nodes are compared in real time based on the transmission process of the corresponding power waveforms;

[0037] If they are not completely consistent, the area where the power waveform is inconsistent will be calibrated abnormally, and synchronously calibrated to the power waveform received by the corresponding power node. During the specific comparison, the initial generation point of the corresponding power waveform is aligned with the receiving point of the power waveform received by the corresponding node to perform a consistency comparison of the corresponding waveforms to determine whether the two sets of power waveforms have the same direction and value, so as to lock the corresponding abnormal waveform area and then perform associated calibration;

[0038] Step 2: Perform waveform analysis on the received power waveform with abnormal calibration, confirm the frequency of part of the waveform in the abnormal area, and then use the power waveform generated by the previous power node associated with the power waveform as the reference waveform to identify whether part of the waveform is harmonic. Specifically, under normal circumstances, the power waveform generally does not have abnormalities during transmission. When there are corresponding abnormalities, it is either the relevant influence caused by harmonics that causes the waveform to change, thereby causing the corresponding abnormal area. If it is not the relevant influence caused by harmonics, it is the power fluctuation in the corresponding transmission process or other relevant influences in the power transmission process that cause the power waveform to fluctuate. Therefore, in order to solve the specific abnormal situation, it is necessary to identify the specific reason for the change in the waveform. According to different power fluctuation situations, different processing methods are executed to restore the waveform;

[0039] Combination Figure 2 , the specific sub-steps to identify whether this part of the waveform is a harmonic are:

[0040] S21, extract part of the waveform in the abnormal area and confirm the frequency: mark part of the waveform in the abnormal area as an abnormal waveform, determine the peak point of the abnormal waveform, mark the time period between adjacent peak points as T1, and use F1=1÷T1 to confirm the associated frequency F1 corresponding to the abnormal waveform. If the abnormal waveform has only one peak point (as long as the waveform exists, a group of peak points can be determined when confirming the peak point, and the peak point is the associated point position in the corresponding waveform where the value is in the highest state), directly mark the abnormal waveform as a fluctuating waveform;

[0041] S22, based on the calibrated reference waveform, preferentially determine the peak point of the reference waveform, then confirm the time period between the two peak points and calibrate it as T2, and use F2=1÷T2 to confirm the associated frequency F2 corresponding to the reference waveform;

[0042] S23, identifying whether F1 and F2 are in an integer divisibility relationship: F1÷F2=Q, identifying whether Q is an integer, if it is an integer, calibrating the abnormal waveform as a harmonic waveform, if not an integer, calibrating the abnormal waveform as a fluctuating waveform;

[0043] Specifically, through the analysis of the correlation, it is confirmed that the time period confirmed by the partial waveform is 0.5. Then after the correlation processing, the confirmed correlation frequency F1=2, and the time period confirmed by the reference waveform is 2, so the confirmed correlation frequency F2=0.5, so F1 and F2 are in an integer relationship, and F1÷F2=2÷0.5=4, where 4 is an integer, so this abnormal waveform is a harmonic waveform. When a harmonic waveform is generated in the corresponding power waveform, the frequency generated by the harmonic waveform is in an integer relationship with the frequency of the original waveform;

[0044] Step 3: Correlation confirmation is performed on the time nodes generated by some waveforms, and the time features within the reference waveform are locked based on the confirmed correlation period. Subsequently, waveform optimization is performed within the current power node based on this time feature. When some waveforms are harmonic waveforms, waveform optimization is performed by using a filter to perform frequency compensation. When some waveforms are not harmonic waveforms, waveform optimization is performed by using a phase adjustment method. Specifically, when the corresponding waveform is transmitted to this power node, this power node can evaluate whether this part of the waveform is a harmonic waveform or an impact waveform based on the corresponding correlation analysis process, and perform subsequent specific optimization based on the specific evaluation results, so as to ensure the normal transmission and optimization of the power waveform.

[0045] The specific method for determining the time characteristics of this part of the waveform is:

[0046] Based on the initial moment and the end moment of the partial waveform, the associated period is locked, and the associated period is the time length between the initial moment and the end moment;

[0047] Prioritize the interval between the first group of partial waveforms and the initial moment of the waveform, then determine the interval between the end moment of the current partial waveform and the initial moment of the next partial waveform, and record the intervals between adjacent partial waveforms in association;

[0048] When waveform optimization is performed again, the current power node generates the corresponding transmitted power waveform in real time based on the power waveform received in real time, and transmits it to the next power node. During the generation process, based on the determined associated time periods and interval time periods, based on the generated initial moment, the power waveform generated in the subsequent associated time periods is optimized: starting from the initial moment, based on the determined first group of interval time periods, the power waveform is optimized, and the optimization duration is the first group of associated time periods. After the optimization is completed, the optimization process is executed again based on the determined second group of interval time periods, and the optimized time difference is the second group of associated time periods. Based on the determined time characteristics, the subsequent optimization processes are confirmed one by one and optimized step by step. When this power node receives this power waveform, it also needs to transmit this power waveform to other power nodes, so it needs to perform a power waveform transmission conversion process. In this process, waveform optimization can be performed to ensure the normal transmission of the corresponding power waveform. For example, if some waveforms are generated regularly, the confirmed associated time period is 2 minutes, and the generated interval time periods are 1 minute, 3 minutes, 3 minutes, 3 minutes, ..., 3 minutes. Then, this power node performs a 2-minute optimization process 1 minute after the initial moment of generating the waveform, and then performs a 2-minute optimization process every 3 minutes, so as to complete the overall optimization of the corresponding power waveform.

[0049] As this part of the waveform is a harmonic waveform, a filter is used to perform frequency compensation to optimize the waveform:

[0050] Based on the confirmed associated frequency F1 of the harmonic waveform, the specific number G of peak points in the harmonic waveform is identified, and the occurrence frequency P of the harmonic waveform is locked, and P=G-1. Two peak points represent the occurrence of a harmonic waveform once. If there are three peak points, it means that the harmonic waveform appears twice, and so on, and the corresponding occurrence frequency is locked;

[0051] Determine the filter frequency Lv, and Lv = F1 × P to obtain Lv, adjust the filter frequency of the filter to Lv, and use this filter frequency to perform specific waveform optimization, and perform associated optimization in the determined optimization process. Specifically, for the harmonics that appear, directly adjust the filter frequency of the corresponding filter. The filter can effectively optimize the generated associated harmonics to ensure the corresponding frequency optimization process and the overall quality of the generated power waveform;

[0052] For some waveforms that are fluctuating waveforms (that is, not harmonic waveforms), phase adjustment is used to optimize the waveform:

[0053] Identify the inconsistent waveform of the fluctuation waveform from step S11, calibrate the inconsistent waveform as the standard waveform, identify the associated distance between different points at the same vertical position based on the specific comparison process of the fluctuation waveform and the standard waveform, and propose a confirmation method of the associated distance as follows: associated distance = fluctuation waveform point - standard waveform point, the unit length of the distance is proposed in advance by the operator, and based on several groups of associated distances confirmed at different vertical positions, sum up several groups of associated distances, lock the sum value, if the sum value is greater than 0 (indicating that the overall performance state of the fluctuation waveform is above the standard waveform), generate a phase parameter reduction signal, if the sum value is less than 0 (indicating that the overall performance state of the fluctuation waveform is below the standard waveform), generate a phase parameter increase signal, if the sum value = 0, no adjustment is made (indicating that although the fluctuation waveform has fluctuations, the changes have not deviated from the original waveform benchmark, so it may be caused by the power generation point itself, this situation generally does not need to be handled by itself, and will be repaired later);

[0054] When the current power node is executing a specific optimization process, the original phase parameter is gradually changed based on the confirmed phase parameter reduction signal or phase parameter increase signal (the phase parameter reduction signal reduces the original phase parameter, and the phase parameter increase signal increases the original phase parameter). Based on the specific step-by-step adjustment process, the correlation distance between the point of the corresponding adjusted and optimized fluctuation waveform and the point at the same vertical position in the standard waveform is confirmed in real time. When the correlation distance is ≤Y1, the adjustment is stopped, and the adjusted phase parameter is kept unchanged, where Y1 is a preset value, and its specific value is determined by the operator based on experience. Each subsequent related optimization process adopts the same adjustment method, and the adjustment is stopped when the correlation distance is ≤Y1, so as to complete the full optimization of the entire power waveform;

[0055] Specifically, different optimization processes need to be executed for different abnormal waveforms that appear, such as harmonic waveforms or fluctuating waveforms, so that the power waveform can be fully optimized to ensure the overall quality of the power waveform transmitted subsequently. Every time the power waveform passes through a group of power nodes, power monitoring and analysis are required to determine its specific optimization process, so as to achieve better optimization effects.

[0056] Some of the data in the above formulas are dimensionless and numerically calculated. Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0057] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for analyzing waveforms in an electric power system, characterized in that The following steps are involved: Step 1: Based on the point where the power waveform occurs in the power system and the power nodes at different subsequent locations, the power waveform is verified in real time to assess whether the power waveform has any associated changes. If there are any associated changes, abnormal calibration is performed. If there are no associated changes, continuous verification is performed. The specific sub-steps are as follows: Based on the specific power transmission route, the power waveform generated by the previous power node is compared with the power waveform received by the next power node. The occurrence points are also regarded as a group of power nodes to identify whether the corresponding power waveforms before and after are completely consistent: If they are completely consistent, the power waveforms between adjacent power nodes are compared in real time based on the transmission process of the corresponding power waveforms; If they are not completely consistent, the area where the power waveform is inconsistent is calibrated abnormally and synchronously calibrated to the power waveform received by the corresponding power node; Step 2: Perform waveform analysis on the received power waveform with abnormal calibration, confirm the frequency of part of the waveform in the abnormal area, and then use the power waveform generated by the previous power node associated with this power waveform as a reference waveform to identify whether part of the waveform is harmonic; Step 3: Correlate and confirm the time nodes generated by some waveforms, and lock the time characteristics of the time nodes in the reference waveform based on the confirmed correlation period. Then, based on this time characteristic, perform waveform optimization in the current power node. When some waveforms are harmonic waveforms, use filters to perform frequency compensation to optimize the waveform. When some waveforms are not harmonic waveforms, use phase adjustment to optimize the waveform. The specific method is as follows: Based on the initial moment and the end moment of the partial waveform, the associated period is locked, and the associated period is the time length between the initial moment and the end moment; Prioritize the interval between the first group of partial waveforms and the initial moment of the waveform, then determine the interval between the end moment of the current partial waveform and the initial moment of the next partial waveform, and record the intervals between adjacent partial waveforms in association; When the waveform optimization is performed again, the current power node generates the corresponding transmitted power waveform in real time based on the power waveform received in real time, and transmits it to the next power node. In the generation process, based on the determined associated time period and interval time period, based on the generated initial moment, the power waveform generated in the subsequent associated time period is optimized: starting from the initial moment, based on the determined first group of interval time periods, the power waveform is optimized, and its optimization duration is the first group of associated time periods. After the optimization is completed, the optimization process is executed again based on the determined second group of interval time periods, and its optimization duration is the second group of associated time periods. Based on the determined time characteristics, the subsequent optimization processes are confirmed one by one, and the optimization is performed step by step; For some waveforms that are fluctuating, phase adjustment is used to optimize the waveform: Identify the inconsistent waveform of the fluctuating waveform, calibrate the inconsistent waveform as the standard waveform, identify the associated distance between different points at the same vertical position based on the specific comparison process of the fluctuating waveform and the standard waveform, and formulate a confirmation method of the associated distance as follows: associated distance = fluctuating waveform point - standard waveform point, the unit length of the distance is formulated in advance by the operator, and based on several groups of associated distances confirmed at different vertical positions, sum up several groups of associated distances, lock the sum value, if the sum value is greater than 0, generate a phase parameter reduction signal, if the sum value is less than 0, generate a phase parameter increase signal, if the sum value = 0, do not make any adjustment; When the current power node is executing a specific optimization process, the original phase parameter is gradually changed based on the confirmed phase parameter reduction signal or phase parameter increase signal. Based on the specific step-by-step adjustment process, the correlation distance between the point of the corresponding adjusted optimized fluctuation waveform and the point at the same vertical position in the standard waveform is confirmed in real time. When the correlation distance is ≤Y1, the adjustment is stopped and the adjusted phase parameter is kept unchanged, where Y1 is a preset value. Each subsequent related optimization process adopts the same adjustment method until the correlation distance is ≤Y1. The adjustment is stopped.

2. A method for analyzing waveforms in an electric power system according to claim 1, characterized in that: In step 2, the specific method of identifying whether a part of the waveform is a harmonic is: S21, extract part of the waveform in the abnormal area and confirm the frequency: mark part of the waveform in the abnormal area as an abnormal waveform, determine the peak point of the abnormal waveform, mark the time period between adjacent peak points as T1, and use F1=1÷T1 to confirm the associated frequency F1 corresponding to the abnormal waveform. If the abnormal waveform has only one peak point, directly mark the abnormal waveform as a fluctuating waveform; S22, based on the calibrated reference waveform, preferentially determine the peak point of the reference waveform, then confirm the time period between the two peak points and calibrate it as T2, and use F2=1÷T2 to confirm the associated frequency F2 corresponding to the reference waveform; S23, identify whether F1 and F2 are in an integer divisibility relationship: F1÷F2=Q, identify whether Q is an integer, if it is an integer, calibrate the abnormal waveform as a harmonic waveform, if not an integer, calibrate the abnormal waveform as a fluctuating waveform.

3. A method for analyzing waveforms in an electric power system according to claim 1, characterized in that: As this part of the waveform is a harmonic waveform, a filter is used to perform frequency compensation to optimize the waveform: Based on the confirmed correlation frequency F1 of the harmonic waveform, the specific number G of peak points in the harmonic waveform is identified, and the occurrence frequency P of the harmonic waveform is locked, and P=G-1; The filtering frequency Lv is determined, and Lv=F1×P to obtain Lv, the filtering frequency of the filter is adjusted to Lv, and this filtering frequency is used to perform specific waveform optimization, and associated optimization is performed in the determined optimization process.

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