CN114325076B - Voltage sag detection method, detection device and processor - Google Patents
Voltage sag detection method, detection device and processor Download PDFInfo
- Publication number
- CN114325076B CN114325076B CN202111518778.8A CN202111518778A CN114325076B CN 114325076 B CN114325076 B CN 114325076B CN 202111518778 A CN202111518778 A CN 202111518778A CN 114325076 B CN114325076 B CN 114325076B
- Authority
- CN
- China
- Prior art keywords
- sub
- offset
- voltage
- voltage waveform
- amplitude
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 claims abstract description 36
- 238000005070 sampling Methods 0.000 claims description 52
- 238000004364 calculation method Methods 0.000 claims description 30
- 230000000630 rising effect Effects 0.000 claims description 19
- 238000012545 processing Methods 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 8
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000004422 calculation algorithm Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000011897 real-time detection Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000011895 specific detection Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Abstract
The application provides a voltage sag detection method, a detection device and a processor. The method comprises the following steps: acquiring a voltage waveform to be detected, wherein the voltage waveform comprises sub-voltage waveforms of a plurality of periods; calculating the offset of the voltage according to at least two continuous sub-voltage waveforms; and determining whether the voltage waveform to be detected has voltage sag according to the offset. In the scheme, at least two continuous sub-voltage waveforms are adopted to calculate the offset of the voltage, and as the period of the at least two continuous sub-voltage waveforms is continuous, the problem of delay caused by long period phase difference is avoided, and filter processing is not needed, so that whether the voltage waveform to be detected has voltage sag or not can be directly and accurately determined according to the offset of the voltage.
Description
Technical Field
The application relates to the technical field of voltage sag detection, in particular to a voltage sag detection method, a detection device, a computer readable storage medium and a processor.
Background
With the development of industrialization and automation, modern enterprises put higher demands on the quality of electric energy, and according to the definition of institute of electrical and electronics engineers IEEE, voltage sag refers to the rapid decrease of the effective value of the supplied voltage below the rated voltage, which belongs to one of the most common electric energy quality problems in an electric power system, and has become an important concern of society, and the loss of voltage sag to industries such as precision manufacturing, semiconductor industry, public service and the like is also increasing.
How to accurately and rapidly measure the voltage effective value level, judge whether voltage sag occurs or not, switch standby power in time, be the basis and the premise that a dynamic voltage compensator and an emergency power lamp device carry out voltage compensation or rapid switching, be the premise of guaranteeing the power quality of users and guaranteeing the safe and stable operation of all electric equipment under a bus, and therefore have very important significance for the real-time detection of the voltage sag.
The most common method in the current technical field is a method for solving the root mean square value by adopting an instantaneous voltage dq decomposition method and a sliding method, but the two methods have the problem of lower detection accuracy:
in the instantaneous voltage dq decomposition method, a low-pass filter is required for filtering, so that a larger delay inevitably occurs in the time domain, meanwhile, a certain delay exists in the output of the phase-locked loop, the delay is generally more than 5ms, the instantaneity is low, and the detection accuracy is low;
in the sliding root mean square method, firstly, complex noise and harmonic exist in the power grid voltage, if the root mean square is directly calculated, the obtained result error is larger, so that erroneous judgment is likely to occur, secondly, the algorithm has poorer real-time performance, at least has a delay of half fundamental wave period, the delay is generally more than 10ms, the real-time performance is also low, and the detection accuracy is also lower.
Disclosure of Invention
The application mainly aims to provide a voltage sag detection method, a detection device, a computer readable storage medium and a processor, so as to solve the problem of low accuracy of detecting the voltage sag in the prior art.
According to an aspect of an embodiment of the present application, there is provided a method for detecting a voltage dip, including: acquiring a voltage waveform to be detected, wherein the voltage waveform comprises sub-voltage waveforms of a plurality of periods; calculating the offset of the voltage according to at least two continuous sub-voltage waveforms, wherein the offset of the voltage is used for representing the amplitude fluctuation condition of the voltage waveforms; and determining whether the voltage waveform to be detected has voltage sag or not according to the offset.
Optionally, calculating the offset of the voltage according to at least two consecutive sub-voltage waveforms includes: acquiring the amplitude values of N+1 continuous sub-voltage waveforms; determining the instantaneous offset corresponding to the Mth sub-voltage waveform according to a plurality of the amplitude values, wherein M is more than 1 and less than or equal to N+1; calculating the average value of the instantaneous offset corresponding to a plurality of phases of the Q sub-voltage waveform to obtain an average offset, wherein Q is more than 1 and less than or equal to N; accumulating the plurality of average offset values to obtain accumulated offset values; and obtaining the total offset of the (N+1) th sub-voltage waveform according to the accumulated offset and the instantaneous offset corresponding to the (N+1) th sub-voltage waveform.
Optionally, before determining the instantaneous offset corresponding to the mth sub-voltage waveform according to a plurality of the magnitudes, the method further includes: the amplitude of the sub-voltage waveform of the first period is determined as a reference amplitude.
Optionally, determining, according to a plurality of the magnitudes, an instantaneous offset corresponding to the mth sub-voltage waveform includes: obtaining the difference value between the absolute value of the amplitude of the M sub-voltage waveform and the absolute value of the amplitude of the M-1 sub-voltage waveform with the same phase; and dividing the difference value and the absolute value of the reference amplitude in the same phase to obtain the instantaneous offset corresponding to the M sub-voltage waveform.
Optionally, before calculating an average value of the instantaneous offsets corresponding to the multiple phases of the Q sub-voltage waveform to obtain an average offset, the method further includes: and deleting the instantaneous offset corresponding to a plurality of sampling points around the zero crossing point of the rising edge and the falling edge.
Optionally, obtaining the total offset of the n+1th sub-voltage waveform according to the accumulated offset and the instantaneous offset corresponding to the n+1th sub-voltage waveform, including: and calculating the sum of the accumulated offset and the instantaneous offset corresponding to the (N+1) th sub-voltage waveform, wherein the sum is the total offset of the (N+1) th sub-voltage waveform.
Optionally, determining whether the voltage waveform to be detected has a voltage sag according to the offset includes: determining that a voltage dip occurs if the total offset is greater than a predetermined threshold; and determining that no voltage sag occurs in the case that the total offset is less than or equal to the preset threshold value.
According to another aspect of the embodiment of the present application, there is also provided a device for detecting a voltage dip, including: an acquisition unit configured to acquire a voltage waveform to be detected, the voltage waveform including sub-voltage waveforms of a plurality of periods; the calculating unit is used for calculating the offset of the voltage according to at least two continuous sub-voltage waveforms, and the offset of the voltage is used for representing the amplitude fluctuation condition of the voltage waveforms; a first determining unit configured to determine whether a voltage sag occurs in the voltage waveform to be detected according to the offset
According to still another aspect of the embodiments of the present application, there is also provided a computer-readable storage medium including a stored program, wherein the program performs any one of the methods.
According to still another aspect of the embodiment of the present application, there is further provided a processor, where the processor is configured to execute a program, where the program executes any one of the methods.
In the embodiment of the application, a voltage waveform to be detected is firstly obtained, wherein the voltage waveform comprises a plurality of periods of sub-voltage waveforms, then a voltage offset is calculated according to at least two continuous sub-voltage waveforms, and finally whether voltage sag occurs in the voltage waveform to be detected is determined according to the offset. In the scheme, at least two continuous sub-voltage waveforms are adopted to calculate the offset of the voltage, and as the period of the at least two continuous sub-voltage waveforms is continuous, the problem of delay caused by long period phase difference does not exist.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:
FIG. 1 is a flow chart of a method for detecting a voltage dip according to an embodiment of the application;
FIG. 2 shows a schematic flow chart for determining a rising edge zero crossing;
FIG. 3 shows a schematic flow chart of determining an instantaneous offset;
FIG. 4 is a schematic diagram showing a structure of a voltage sag detection device according to an embodiment of the present application; .
FIG. 5 shows a schematic diagram of an acquired voltage waveform to be detected;
FIG. 6 shows a schematic diagram of the resulting instantaneous offset;
FIG. 7 shows a schematic diagram of the resulting average offset;
FIG. 8 shows a schematic diagram of the resulting accumulated offset;
FIG. 9 shows a schematic diagram of the resulting total offset;
fig. 10 shows a schematic diagram for determining whether a dip in voltage occurs.
Detailed Description
It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.
In order that those skilled in the art will better understand the present application, a technical solution in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe the embodiments of the application herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. Furthermore, in the description and in the claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element or "connected" to the other element through a third element.
As described in the background art, in order to solve the above-mentioned problems, in an exemplary embodiment of the present application, a voltage sag detection method, a detection device, a computer-readable storage medium and a processor are provided.
According to an embodiment of the application, a voltage sag detection method is provided.
Fig. 1 is a flow chart of a method of detecting a voltage dip according to an embodiment of the application. As shown in fig. 1, the method comprises the steps of:
step S101, obtaining a voltage waveform to be detected, wherein the voltage waveform comprises sub-voltage waveforms of a plurality of periods;
step S102, calculating the offset of the voltage according to at least two continuous sub-voltage waveforms, wherein the offset of the voltage is used for representing the amplitude fluctuation condition of the voltage waveforms;
step S103, determining whether voltage sag occurs in the voltage waveform to be detected according to the offset.
In the method, firstly, a voltage waveform to be detected is obtained, the voltage waveform comprises sub-voltage waveforms with a plurality of periods, then, the offset of the voltage is calculated according to at least two continuous sub-voltage waveforms, and finally, whether the voltage waveform to be detected has voltage sag or not is determined according to the offset. In the scheme, at least two continuous sub-voltage waveforms are adopted to calculate the offset of the voltage, and as the period of the at least two continuous sub-voltage waveforms is continuous, the problem of delay caused by long period phase difference does not exist.
It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer executable instructions, and that although a logical order is illustrated in the flowcharts, in some cases the steps illustrated or described may be performed in an order other than that illustrated herein.
In one embodiment, the amplitude u (t) of the voltage waveform can be converted from an analog signal to a digital signal u (n), where n is the number of sampling sequences, and in order to further ensure the accuracy of detection, the sampling frequency should be greater than 25.6kHz/s, i.e. the number of sampling points per cycle is greater than 512.
In one embodiment of the present application, calculating the offset of the voltage according to at least two consecutive sub-voltage waveforms includes: acquiring the amplitude values of N+1 continuous sub-voltage waveforms; determining the instantaneous offset corresponding to the Mth sub-voltage waveform according to a plurality of the amplitude values, wherein M is more than 1 and less than or equal to N+1; calculating the average value of the instantaneous offset corresponding to a plurality of phases of the Q sub-voltage waveform to obtain an average offset, wherein Q is more than 1 and less than or equal to N; accumulating the plurality of average offset values to obtain accumulated offset values; and obtaining the total offset of the n+1th sub-voltage waveform according to the accumulated offset and the instantaneous offset corresponding to the n+1th sub-voltage waveform. In the embodiment, the amplitude of the sub-voltage waveform is calculated for a plurality of times to obtain the total offset, and whether the voltage waveform to be detected has voltage sag or not can be further accurately determined according to the total offset.
In still another embodiment of the present application, before determining the instantaneous offset corresponding to the mth sub-voltage waveform according to a plurality of the magnitudes, the method further includes: the amplitude of the sub-voltage waveform of the first period is determined as a reference amplitude. In this embodiment, the amplitude of the sub-voltage waveform in the first period may be extracted separately and used as the reference amplitude, so that it is ensured that the instantaneous offset may be determined more accurately according to the reference amplitude.
In a specific embodiment, according to the obtained voltage waveform, a rising edge zero-crossing point is further determined, as shown in fig. 2, the specific steps are that firstly, the amplitude of an nth sampling point is obtained, whether the amplitude of the nth sampling point is greater than or equal to 0 is determined, if the amplitude of an nth sampling point is greater than or equal to 0, whether the amplitude of an N-1 sampling point is smaller than 0 is determined, if the amplitude of an N-1 sampling point is smaller than 0, a sampling point with a small absolute value of the amplitude of the nth sampling point and the amplitude of the N-1 sampling point is used as the zero-crossing point, and if the first rising edge zero-crossing point is detected, the amplitude of the sub-voltage waveform in the first period is stored in a register until the arrival of the rising edge zero-crossing point in the next period, and meanwhile, the amplitude of the sub-voltage waveform in the first period is stored in a memory as the reference amplitude.
In still another embodiment of the present application, determining the instantaneous offset corresponding to the mth sub-voltage waveform according to the plurality of magnitudes includes: obtaining the difference value between the absolute value of the amplitude of the M sub-voltage waveform and the absolute value of the amplitude of the M-1 sub-voltage waveform with the same phase; and dividing the difference value by the absolute value of the reference amplitude value with the same phase to obtain the instantaneous offset corresponding to the M sub-voltage waveform. In this embodiment, the instantaneous offset can be obtained by performing an operation on the magnitudes of two continuous sub-voltage waveforms to obtain an operation result, and performing an operation on the operation result and the reference magnitude.
Specifically, the instantaneous offset is Δ, and the calculation formula isWherein U (M) represents the amplitude of the Mth sub-voltage waveform, U (B) represents the amplitude of the M-1 st sub-voltage waveform in phase with the M sub-voltage waveform, and U (C) represents the reference amplitude.
In yet another embodiment, the average offset isThe calculation formula is as follows:wherein Q represents the Q-th period, N represents the number of sampling points per period, since the first period is not instantaneousTime offset, therefore, there is no average offset in the first period, the cumulative offset is ΣΔ (N), and its calculation formula is +.>Wherein->Representing the average offset for the Q cycle.
In another embodiment of the present application, before calculating an average value of the instantaneous offsets corresponding to the phases of the Q sub-voltage waveform to obtain an average offset, the method further includes: and deleting the instantaneous offset corresponding to a plurality of sampling points around the zero crossing point of the rising edge and the falling edge. In this embodiment, the amplitude of the acquired voltage waveform is very close to 0 near the zero crossing point, so that a large error occurs when division is performed near the zero crossing point, and therefore, the instantaneous offsets corresponding to a plurality of sampling points around the zero crossing point of the rising edge and the falling edge are deleted, thereby further ensuring higher detection accuracy.
Specifically, each of the zero-crossing points of the rising edge and the falling edge can be omittedAnd the instantaneous offset corresponding to the sampling points is represented by N, wherein N represents the number of the sampling points in each period, and if the number of the sampling points in the previous and subsequent periods is inconsistent, the two sampling points are smaller.
In yet another specific embodiment, determining the instantaneous offset may further include the steps of, as shown in FIG. 3, first, obtaining the amplitude of the M-1 th sub-voltage waveform stored in the register, obtaining the amplitude of the sub-voltage waveform of the first period stored in the memory, obtaining the amplitude of the M-th sub-voltage waveform, and comparing the rising edge with the falling edge around the zero crossing pointDeleting the instantaneous offset corresponding to each sampling point to obtain the absolute value of the amplitude value and the same phase of the Mth sub-voltage waveformThe method comprises the steps of dividing the difference value of the absolute values of the amplitudes of M-1 sub-voltage waveforms with the absolute value of the reference amplitude of the same phase to obtain an instantaneous offset corresponding to the M-1 sub-voltage waveform, updating the content stored in a register, storing the latest acquired amplitude of the M-1 sub-voltage waveform, ending the sampling of the amplitude of the M-1 sub-voltage waveform, and calculating the instantaneous offset, wherein if the number of sampling points of the M-1 sub-voltage waveform is inconsistent with that of the M-1 sub-voltage waveform, when the number of sampling points of the M-1 sub-voltage waveform is smaller than that of the M-1 sub-voltage waveform, redundant sampling points of the M-1 sub-voltage waveform are deleted, the instantaneous offset of redundant sampling points is not calculated, and if the number of sampling points of the M-1 sub-voltage waveform is larger than that of the M sub-voltage waveform, whether redundant sampling points need to be deleted or not need to be considered.
In a specific embodiment of the present application, obtaining a total offset of the n+1th sub-voltage waveform according to the accumulated offset and the instantaneous offset corresponding to the n+1th sub-voltage waveform includes: and calculating the sum of the accumulated offset and the instantaneous offset corresponding to the (n+1) th sub-voltage waveform, wherein the sum is the total offset of the (n+1) th sub-voltage waveform. In this embodiment, the sum of the accumulated offset and the instantaneous offset corresponding to the n+1th sub-voltage waveform is directly used as the total offset, so that the embodiment can determine the total offset more directly and accurately, that is, the total offset of the n+1th voltage waveform can be obtained more accurately, and the detection accuracy of the scheme is further ensured to be higher.
Specifically, the total offset is Δ s The calculation formula is as follows: delta s (QN+M)＝∑Δ(Q)+Δ(M)。
In still another specific embodiment of the present application, determining whether the voltage waveform to be detected has a voltage sag according to the offset includes: determining that voltage sag occurs under the condition that the total offset is larger than a preset threshold value; and determining that no voltage sag occurs in the case that the total offset is smaller than or equal to the preset threshold value. In this embodiment, whether the voltage waveform to be detected has a voltage sag can be determined more directly and accurately according to the total offset, so that the detection time is further shortened, and the real-time performance of the detection is further improved.
It should be noted that the predetermined threshold may be 10%, but is not limited to 10%, and may be any other possible predetermined threshold, and for the window length of the sub-waveform, may beIf the window length is small, this will also result in a low accuracy of detection, and a person skilled in the art can choose a suitable window length according to the actual situation.
In the above embodiment, the specific detection speed is determined by the window length when the window length isWhen the detection speed is 0.625ms, namely after the voltage sag occurs for 0.625ms, the occurrence of the voltage sag can be identified, which is far higher than the detection speed in the prior art, the electric energy quality can be better monitored, the safe operation of the electric equipment is ensured, and in practical application, if the window length is lower than ++>In this case, the detection speed can be further shortened.
The embodiment of the application also provides a device for detecting the voltage sag, and the device for detecting the voltage sag can be used for executing the method for detecting the voltage sag provided by the embodiment of the application. The following describes a voltage sag detection device provided by an embodiment of the present application.
Fig. 4 is a schematic diagram of a voltage sag detection device according to an embodiment of the present application. As shown in fig. 4, the apparatus includes:
an acquisition unit 10 for acquiring a voltage waveform to be detected, the voltage waveform including sub-voltage waveforms of a plurality of periods;
a calculating unit 20, configured to calculate a voltage offset according to at least two consecutive sub-voltage waveforms, where the voltage offset is used to represent an amplitude fluctuation condition of the voltage waveforms;
a first determining unit 30, configured to determine whether a voltage sag occurs in the voltage waveform to be detected according to the offset.
In the above device, the obtaining unit obtains a voltage waveform to be detected, where the voltage waveform includes sub-voltage waveforms with multiple periods, the calculating unit calculates an offset of a voltage according to at least two continuous sub-voltage waveforms, and the first determining unit determines whether a voltage sag occurs in the voltage waveform to be detected according to the offset. In the scheme, at least two continuous sub-voltage waveforms are adopted to calculate the offset of the voltage, and as the period of the at least two continuous sub-voltage waveforms is continuous, the problem of delay caused by long period phase difference does not exist.
In one embodiment of the present application, the calculating unit includes an acquiring module, a first calculating module, a second calculating module, a third calculating module and a fourth calculating module, where the acquiring module is configured to acquire n+1 continuous magnitudes of the sub-voltage waveforms; the first calculation module is used for determining the instantaneous offset corresponding to the M < M > sub-voltage waveform according to a plurality of the amplitude values, wherein M is more than 1 and less than or equal to N+1; the second calculation module is used for calculating the average value of the instantaneous offset corresponding to a plurality of phases of the Q sub-voltage waveform to obtain the average offset, wherein Q is more than 1 and less than or equal to N; the third calculation module is used for accumulating the plurality of average offset values to obtain accumulated offset values; the fourth calculation module is configured to obtain a total offset of the n+1th sub-voltage waveform according to the accumulated offset and the instantaneous offset corresponding to the n+1th sub-voltage waveform. In the embodiment, the amplitude of the sub-voltage waveform is calculated for a plurality of times to obtain the total offset, and whether the voltage waveform to be detected has voltage sag or not can be further accurately determined according to the total offset.
In still another embodiment of the present application, the apparatus further includes a second determining unit, where the second determining unit is configured to determine, before determining the instantaneous offset corresponding to the mth sub-voltage waveform according to the plurality of magnitudes, the magnitude of the sub-voltage waveform in the first period as the reference magnitude. In this embodiment, the amplitude of the sub-voltage waveform in the first period may be extracted separately and used as the reference amplitude, so that it is ensured that the instantaneous offset may be determined more accurately according to the reference amplitude.
In yet another embodiment of the present application, the first calculation module includes a first calculation sub-module and a second calculation sub-module, where the first calculation sub-module is configured to obtain a difference between an absolute value of an amplitude of an mth sub-voltage waveform and an absolute value of an amplitude of an M-1 th sub-voltage waveform with the same phase; the second calculation submodule is used for carrying out division operation on the difference value and the absolute value of the reference amplitude value with the same phase to obtain the instantaneous offset corresponding to the Mth sub-voltage waveform. In this embodiment, the instantaneous offset can be obtained by performing an operation on the magnitudes of two continuous sub-voltage waveforms to obtain an operation result, and performing an operation on the operation result and the reference magnitude.
In another embodiment of the present application, the apparatus further includes a deleting unit, configured to delete the instantaneous offsets corresponding to the plurality of sampling points around the zero crossing point of the rising edge and the falling edge before calculating an average value of the instantaneous offsets corresponding to the plurality of phases of the Q-th sub-voltage waveform to obtain an average offset. In this embodiment, the amplitude of the acquired voltage waveform is very close to 0 near the zero crossing point, so that a large error occurs when division is performed near the zero crossing point, and therefore, the instantaneous offsets corresponding to a plurality of sampling points around the zero crossing point of the rising edge and the falling edge are deleted, thereby further ensuring higher detection accuracy.
In a specific embodiment of the present application, the fourth calculation module includes a third calculation sub-module, and the third calculation sub-module is configured to calculate a sum of the accumulated offset and the instantaneous offset corresponding to the n+1th sub-voltage waveform, where the sum is the total offset of the n+1th sub-voltage waveform. In this embodiment, the sum of the accumulated offset and the instantaneous offset corresponding to the n+1th sub-voltage waveform is directly used as the total offset, so that the embodiment can determine the total offset more directly and accurately, that is, the total offset of the n+1th voltage waveform can be obtained more accurately, and the detection accuracy of the scheme is further ensured to be higher.
In yet another specific embodiment of the present application, the first determining unit includes a first determining module and a second determining module, where the first determining module is configured to determine that a voltage sag occurs if the total offset is greater than a predetermined threshold; the second determining module is configured to determine that no voltage sag occurs if the total offset is less than or equal to the predetermined threshold. In this embodiment, whether the voltage waveform to be detected has a voltage sag can be determined more directly and accurately according to the total offset, so that the detection time is further shortened, and the real-time performance of the detection is further improved.
The voltage sag detection device comprises a processor and a memory, wherein the acquisition unit, the calculation unit, the first determination unit and the like are stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions.
The processor includes a kernel, and the kernel fetches the corresponding program unit from the memory. The kernel can be provided with one or more than one, and the accuracy of detecting the voltage sag is improved by adjusting kernel parameters.
The memory may include volatile memory, random Access Memory (RAM), and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM), among other forms in computer readable media, the memory including at least one memory chip.
The embodiment of the application provides a computer readable storage medium, wherein a program is stored on the computer readable storage medium, and the program is executed by a processor to realize the voltage sag detection method.
The embodiment of the application provides a processor, which is used for running a program, wherein the method for detecting the voltage sag is executed when the program runs.
The embodiment of the application provides equipment, which comprises a processor, a memory and a program stored in the memory and capable of running on the processor, wherein the processor realizes at least the following steps when executing the program:
step S101, obtaining a voltage waveform to be detected, wherein the voltage waveform comprises sub-voltage waveforms of a plurality of periods;
step S102, calculating the offset of the voltage according to at least two continuous sub-voltage waveforms, wherein the offset of the voltage is used for representing the amplitude fluctuation condition of the voltage waveforms;
step S103, determining whether voltage sag occurs in the voltage waveform to be detected according to the offset.
The device herein may be a server, PC, PAD, cell phone, etc.
The application also provides a computer program product adapted to perform, when executed on a data processing device, a program initialized with at least the following method steps:
step S101, obtaining a voltage waveform to be detected, wherein the voltage waveform comprises sub-voltage waveforms of a plurality of periods;
step S102, calculating the offset of the voltage according to at least two continuous sub-voltage waveforms, wherein the offset of the voltage is used for representing the amplitude fluctuation condition of the voltage waveforms;
step S103, determining whether voltage sag occurs in the voltage waveform to be detected according to the offset.
In order that the technical solution of the present application may be more clearly understood by those skilled in the art, the technical solution and technical effects of the present application will be described below with reference to specific embodiments.
Examples
The embodiment relates to a voltage sag detection method, which comprises the following steps:
acquiring a voltage waveform to be detected, wherein the length of the voltage waveform to be detected is 1s, the voltage waveform is acquired by adopting the sampling frequency of 25.6kHz/s, the number of sampling points of each period is 512, the voltage waveform comprises a plurality of sub-voltage waveforms in periods, as shown in figure 5, the amplitude of the voltage waveform which is normal in the first 0.2s is reduced to 0.95 times of a rated value, the amplitude of the voltage waveform which is 0.3-0.4 s is reduced to 0.92 times of the rated value, the amplitude of the voltage waveform which is 0.4-0.6 s is reduced to 0.88 times of the rated value, the amplitude of the voltage waveform which is 0.6-0.8 s is reduced to 0.6 times of the rated value, and the amplitude of the voltage waveform which is 0.8-1 s is restored to the rated value, wherein voltage sag occurs in 0.4-0.8 s;
determining the amplitude of the sub-voltage waveform of the first period as a reference amplitude, and obtaining the difference value between the absolute value of the amplitude of the M-th sub-voltage waveform and the absolute value of the amplitude of the M-1 th sub-voltage waveform with the same phase; dividing the absolute value of the reference amplitude of the same phase by the difference value, deleting the instantaneous offset corresponding to a plurality of sampling points around the zero crossing point of the rising edge and the falling edge to obtain the instantaneous offset corresponding to the M sub-voltage waveform, wherein the obtained instantaneous offset is shown in figure 6;
calculating the average value of instantaneous offset corresponding to a plurality of phases of the Q sub-voltage waveform to obtain an average offset, wherein Q is more than 1 and less than or equal to N, and the obtained average offset is shown in figure 7;
accumulating the plurality of average offsets to obtain an accumulated offset, wherein the accumulated offset is shown in fig. 8;
calculating the sum of the accumulated offset and the instantaneous offset corresponding to the (n+1) th sub-voltage waveform to obtain the total offset of the (n+1) th sub-voltage waveform, wherein the total offset is shown in fig. 9;
the length of the window isN represents the sampling point of each periodAs shown in fig. 10, a "1" indicates that a voltage dip occurs, and a "0" indicates that no voltage dip occurs;
according to the judgment result, it can be determined that the voltage sag occurs when the absolute value of the amplitude of the voltage is lower than 10% of the rated value, and the voltage sag can be detected within 1.26ms, so that the detection speed is greatly improved.
In the foregoing embodiments of the present application, the descriptions of the embodiments are emphasized, and for a portion of this disclosure that is not described in detail in this embodiment, reference is made to the related descriptions of other embodiments.
In the several embodiments provided in the present application, it should be understood that the disclosed technology may be implemented in other manners. The above-described embodiments of the apparatus are merely exemplary, and the division of the units may be a logic function division, and there may be another division manner when actually implemented, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some interfaces, units or modules, or may be in electrical or other forms.
The units described above as separate components may or may not be physically separate, and components shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units described above, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the above-mentioned method of the various embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a removable hard disk, a magnetic disk, or an optical disk, or other various media capable of storing program codes.
From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:
1) According to the voltage sag detection method, a voltage waveform to be detected is firstly obtained, the voltage waveform comprises a plurality of periods of sub-voltage waveforms, then the offset of the voltage is calculated according to at least two continuous sub-voltage waveforms, and finally whether the voltage waveform to be detected has the voltage sag or not is determined according to the offset. In the scheme, at least two continuous sub-voltage waveforms are adopted to calculate the offset of the voltage, and as the period of the at least two continuous sub-voltage waveforms is continuous, the problem of delay caused by long period phase difference does not exist.
2) According to the voltage sag detection device, the acquisition unit acquires the voltage waveform to be detected, the voltage waveform comprises a plurality of periods of sub-voltage waveforms, the calculation unit calculates the offset of the voltage according to at least two continuous sub-voltage waveforms, and the first determination unit determines whether the voltage waveform to be detected has the voltage sag according to the offset. In the scheme, at least two continuous sub-voltage waveforms are adopted to calculate the offset of the voltage, and as the period of the at least two continuous sub-voltage waveforms is continuous, the problem of delay caused by long period phase difference does not exist.
The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, and various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (7)
1. A method for detecting a voltage dip, comprising:
acquiring a voltage waveform to be detected, wherein the voltage waveform comprises sub-voltage waveforms of a plurality of periods;
calculating the offset of the voltage according to at least two continuous sub-voltage waveforms, wherein the offset of the voltage is used for representing the amplitude fluctuation condition of the voltage waveforms;
determining whether the voltage waveform to be detected has voltage sag or not according to the offset;
calculating an offset of the voltage from at least two consecutive sub-voltage waveforms, comprising:
acquiring the amplitude values of N+1 continuous sub-voltage waveforms;
determining the instantaneous offset corresponding to the Mth sub-voltage waveform according to a plurality of the amplitude values, wherein M is more than 1 and less than or equal to N+1;
calculating the average value of the instantaneous offset corresponding to a plurality of phases of the Q sub-voltage waveform to obtain an average offset, wherein Q is more than 1 and less than or equal to N;
accumulating the plurality of average offset values to obtain accumulated offset values;
obtaining the total offset of the (N+1) -th sub-voltage waveform according to the accumulated offset and the instantaneous offset corresponding to the (N+1) -th sub-voltage waveform;
before determining the instantaneous offset corresponding to the mth sub-voltage waveform according to the plurality of the magnitudes, the method further includes:
determining the amplitude of the sub-voltage waveform of the first period as a reference amplitude;
according to the obtained voltage waveform, a rising edge zero crossing point is further determined, the amplitude of an N sampling point is obtained, whether the amplitude of the N sampling point is larger than or equal to 0 is determined, whether the amplitude of an N-1 sampling point is smaller than 0 is determined under the condition that the amplitude of the N sampling point is larger than or equal to 0, under the condition that the amplitude of the N-1 sampling point is smaller than 0, a sampling point with a small absolute value in the amplitude of the N sampling point and the amplitude of the N-1 sampling point is taken as the zero crossing point, under the condition that a first rising edge zero crossing point is detected, the amplitude of the sub-voltage waveform in a first period is stored in a register until the rising edge zero crossing point of a next period arrives, and meanwhile, the amplitude of the sub-voltage waveform in the first period is stored in a memory to be taken as the reference amplitude;
according to the plurality of amplitude values, determining the instantaneous offset corresponding to the Mth sub-voltage waveform, which comprises the following steps:
obtaining the difference value between the absolute value of the amplitude of the M sub-voltage waveform and the absolute value of the amplitude of the M-1 sub-voltage waveform with the same phase;
dividing the difference value with the absolute value of the reference amplitude value with the same phase to obtain the instantaneous offset corresponding to the M sub-voltage waveform,
wherein the instantaneous offset is delta, and the calculation formula is as followsWherein U (M) represents the amplitude of the M < th > sub-voltage waveform, U (B) represents the M < 1 > in phase with the M < th > sub-voltage waveformThe magnitude of the sub-voltage waveform,
u (C) | represents the reference amplitude;
wherein the average offset isThe calculation formula is as follows:
wherein Q represents the Q-th period, N represents the number of sampling points of each period, and the average offset is not found in the first period because the first period has no instantaneous offset, the accumulated offset is ΣΔ (N), and the calculation formula is +.>Wherein->Representing the average offset for the Q cycle.
2. The method of claim 1, wherein prior to calculating an average of the instantaneous offsets for the plurality of phases of the Q sub-voltage waveform to obtain an average offset, the method further comprises:
and deleting the instantaneous offset corresponding to a plurality of sampling points around the zero crossing point of the rising edge and the falling edge.
3. The method of claim 1, wherein obtaining a total offset of the n+1th sub-voltage waveform from the accumulated offset and the instantaneous offset corresponding to the n+1th sub-voltage waveform comprises:
and calculating the sum of the accumulated offset and the instantaneous offset corresponding to the (N+1) th sub-voltage waveform, wherein the sum is the total offset of the (N+1) th sub-voltage waveform.
4. A method according to claim 3, wherein determining whether a voltage dip has occurred in the voltage waveform to be detected based on the offset comprises:
determining that a voltage dip occurs if the total offset is greater than a predetermined threshold;
and determining that no voltage sag occurs in the case that the total offset is less than or equal to the preset threshold value.
5. A voltage sag detection device, comprising:
an acquisition unit configured to acquire a voltage waveform to be detected, the voltage waveform including sub-voltage waveforms of a plurality of periods;
the calculating unit is used for calculating the offset of the voltage according to at least two continuous sub-voltage waveforms, and the offset of the voltage is used for representing the amplitude fluctuation condition of the voltage waveforms;
the first determining unit is used for determining whether the voltage waveform to be detected has voltage sag or not according to the offset;
the computing unit comprises an acquisition module, a first computing module, a second computing module, a third computing module and a fourth computing module, wherein the acquisition module is used for acquiring the amplitude values of N+1 continuous sub-voltage waveforms; the first calculation module is used for determining the instantaneous offset corresponding to the M < n+1 > sub-voltage waveform according to a plurality of the amplitude values; the second calculation module is used for calculating the average value of the instantaneous offset corresponding to a plurality of phases of the Q sub-voltage waveform to obtain an average offset, wherein Q is more than 1 and less than or equal to N; the third calculation module accumulates a plurality of the average offset values to obtain accumulated offset values; the fourth calculation module is used for obtaining the total offset of the (N+1) -th sub-voltage waveform according to the accumulated offset and the instantaneous offset corresponding to the (N+1) -th sub-voltage waveform;
the device further comprises a second determining unit, wherein the second determining unit is used for determining the amplitude of the sub-voltage waveform in the first period as a reference amplitude before determining the instantaneous offset corresponding to the Mth sub-voltage waveform according to a plurality of the amplitudes;
according to the obtained voltage waveform, a rising edge zero crossing point is further determined, the amplitude of an N sampling point is obtained, whether the amplitude of the N sampling point is larger than or equal to 0 is determined, whether the amplitude of an N-1 sampling point is smaller than 0 is determined under the condition that the amplitude of the N sampling point is larger than or equal to 0, under the condition that the amplitude of the N-1 sampling point is smaller than 0, a sampling point with a small absolute value in the amplitude of the N sampling point and the amplitude of the N-1 sampling point is taken as the zero crossing point, under the condition that a first rising edge zero crossing point is detected, the amplitude of the sub-voltage waveform in a first period is stored in a register until the rising edge zero crossing point of a next period arrives, and meanwhile, the amplitude of the sub-voltage waveform in the first period is stored in a memory to be taken as the reference amplitude;
the first computing module includes a first computing sub-module and a second computing sub-module,
the first calculation submodule is used for obtaining the difference value between the absolute value of the amplitude of the Mth sub-voltage waveform and the absolute value of the amplitude of the M-1 th sub-voltage waveform with the same phase;
the second calculation submodule is used for carrying out division operation on the difference value and the absolute value of the reference amplitude value with the same phase to obtain the instantaneous offset corresponding to the Mth sub-voltage waveform,
wherein the instantaneous offset is delta, and the calculation formula is as followsWherein U (M) represents the amplitude of the Mth sub-voltage waveform, U (B) represents the amplitude of the M-1 st sub-voltage waveform in phase with the M sub-voltage waveform, and U (C) represents the reference amplitude;
wherein the average offset isThe calculation formula is as follows: />Wherein Q represents the Q-th period, N represents the number of sampling points of each period, and the average offset is not found in the first period because the first period has no instantaneous offset, the accumulated offset is ΣΔ (N), and the calculation formula isWherein->Representing the average offset for the Q cycle.
6. A computer readable storage medium, characterized in that the computer readable storage medium comprises a stored program, wherein the program performs the method of any one of claims 1 to 4.
7. A processor for running a program, wherein the program when run performs the method of any one of claims 1 to 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111518778.8A CN114325076B (en) | 2021-12-13 | 2021-12-13 | Voltage sag detection method, detection device and processor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111518778.8A CN114325076B (en) | 2021-12-13 | 2021-12-13 | Voltage sag detection method, detection device and processor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114325076A CN114325076A (en) | 2022-04-12 |
| CN114325076B true CN114325076B (en) | 2023-10-24 |
Family
ID=81050630
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111518778.8A Active CN114325076B (en) | 2021-12-13 | 2021-12-13 | Voltage sag detection method, detection device and processor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114325076B (en) |
Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU974287A1 (en) * | 1981-05-18 | 1982-11-15 | Предприятие П/Я М-5156 | Digital integrating voltmeter |
| FR2705789A1 (en) * | 1993-05-27 | 1994-12-02 | Electricite De France | Method of identifying a network impedance or rotating machine impedance |
| CN1382993A (en) * | 2002-05-10 | 2002-12-04 | 清华大学 | Remote monitor method and system for instantaneous voltage dropping of electric power network |
| DE102004022719A1 (en) * | 2004-05-07 | 2005-12-01 | Stade, Dietrich, Prof. Dr. | Data extraction for quality assessment of electrical energy involves transferring event data to memory and processing devices, deriving second event data, deriving expansion data, third parameters, processing to assess quality parameters |
| CN1797008A (en) * | 2004-12-28 | 2006-07-05 | 建碁股份有限公司 | Method for detecting load current by using signal in work cycle of pulsewidth modulation controller |
| JP2010017023A (en) * | 2008-07-04 | 2010-01-21 | Shindengen Electric Mfg Co Ltd | Power failure detection device |
| CN201654118U (en) * | 2009-11-30 | 2010-11-24 | 深圳市华力特电气股份有限公司 | Electricity quality detecting device |
| CN105137164A (en) * | 2015-08-06 | 2015-12-09 | 江苏省电力公司苏州供电公司 | Voltage sag on-line monitoring device applied in power system |
| TW201616148A (en) * | 2014-10-30 | 2016-05-01 | 行政院原子能委員會核能研究所 | Apparatus and method for detecting the operation of power supply in an electric utility |
| CN105954563A (en) * | 2016-05-16 | 2016-09-21 | 国电南瑞科技股份有限公司 | Method of identifying tail current based on current derivative and differential current zero-crossing |
| CN106226587A (en) * | 2016-07-01 | 2016-12-14 | 浙江工业大学 | A kind of exchange micro-capacitance sensor voltage dip method for quick based on LES HHT |
| US9941795B1 (en) * | 2017-04-19 | 2018-04-10 | Dialog Semiconductor (Uk) Limited | Circuits and method for extracting average load current in DC-DC switching converters |
| CN108535529A (en) * | 2018-04-25 | 2018-09-14 | 中国人民解放军陆军工程大学 | Consider the exchange micro-capacitance sensor voltage distortion degree evaluation method of fundamental frequency variation |
| CN108957174A (en) * | 2018-06-12 | 2018-12-07 | 国网浙江省电力有限公司台州供电公司 | A kind of voltage dip detection device and method |
| CN113567734A (en) * | 2020-04-29 | 2021-10-29 | 深圳市费思泰克科技有限公司 | Method for detecting power grid voltage signal parameters |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9883259B2 (en) * | 2011-08-15 | 2018-01-30 | Digimarc Corporation | Synchronized metrology in power generation and distribution networks |
-
2021
- 2021-12-13 CN CN202111518778.8A patent/CN114325076B/en active Active
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU974287A1 (en) * | 1981-05-18 | 1982-11-15 | Предприятие П/Я М-5156 | Digital integrating voltmeter |
| FR2705789A1 (en) * | 1993-05-27 | 1994-12-02 | Electricite De France | Method of identifying a network impedance or rotating machine impedance |
| CN1382993A (en) * | 2002-05-10 | 2002-12-04 | 清华大学 | Remote monitor method and system for instantaneous voltage dropping of electric power network |
| DE102004022719A1 (en) * | 2004-05-07 | 2005-12-01 | Stade, Dietrich, Prof. Dr. | Data extraction for quality assessment of electrical energy involves transferring event data to memory and processing devices, deriving second event data, deriving expansion data, third parameters, processing to assess quality parameters |
| CN1797008A (en) * | 2004-12-28 | 2006-07-05 | 建碁股份有限公司 | Method for detecting load current by using signal in work cycle of pulsewidth modulation controller |
| JP2010017023A (en) * | 2008-07-04 | 2010-01-21 | Shindengen Electric Mfg Co Ltd | Power failure detection device |
| CN201654118U (en) * | 2009-11-30 | 2010-11-24 | 深圳市华力特电气股份有限公司 | Electricity quality detecting device |
| TW201616148A (en) * | 2014-10-30 | 2016-05-01 | 行政院原子能委員會核能研究所 | Apparatus and method for detecting the operation of power supply in an electric utility |
| CN105137164A (en) * | 2015-08-06 | 2015-12-09 | 江苏省电力公司苏州供电公司 | Voltage sag on-line monitoring device applied in power system |
| CN105954563A (en) * | 2016-05-16 | 2016-09-21 | 国电南瑞科技股份有限公司 | Method of identifying tail current based on current derivative and differential current zero-crossing |
| CN106226587A (en) * | 2016-07-01 | 2016-12-14 | 浙江工业大学 | A kind of exchange micro-capacitance sensor voltage dip method for quick based on LES HHT |
| US9941795B1 (en) * | 2017-04-19 | 2018-04-10 | Dialog Semiconductor (Uk) Limited | Circuits and method for extracting average load current in DC-DC switching converters |
| CN108535529A (en) * | 2018-04-25 | 2018-09-14 | 中国人民解放军陆军工程大学 | Consider the exchange micro-capacitance sensor voltage distortion degree evaluation method of fundamental frequency variation |
| CN108957174A (en) * | 2018-06-12 | 2018-12-07 | 国网浙江省电力有限公司台州供电公司 | A kind of voltage dip detection device and method |
| CN113567734A (en) * | 2020-04-29 | 2021-10-29 | 深圳市费思泰克科技有限公司 | Method for detecting power grid voltage signal parameters |
Non-Patent Citations (2)
| Title |
|---|
| THREE PHASE CONTROL FOR PWM-SWITCHED AUTOTRANSFORMER VOLTAGE-SAG COMPENSATOR BASED ON PHASE ANGLE ANALYSIS;MUHAMAD MANSOR 等;《Journal of Theoretical and Applied Information Technology》;第30卷(第2期);102-108 * |
| 特高压交流变压器选相合闸技术研究及工程应用;班连庚 等;《电网技术》;第42卷(第4期);1226-1233 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114325076A (en) | 2022-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Padua et al. | Comparative analysis of synchronization algorithms based on PLL, RDFT and Kalman filter | |
| CN109067393B (en) | Phase locking method, device and equipment of power system | |
| Babu et al. | Analysis of SDFT based phase detection system for grid synchronization of distributed generation systems | |
| CN103904693B (en) | Based on the synchronized method that frequency self adaptation Virtual shipyard is estimated | |
| Bai et al. | Fully digital grid synchronization under harmonics and unbalanced conditions | |
| CN114325076B (en) | Voltage sag detection method, detection device and processor | |
| Reza et al. | Robust technique for accurate estimation of single‐phase grid voltage fundamental frequency and amplitude | |
| CN109521273B (en) | Synchronous phasor measurement method, system and device | |
| KR20160064695A (en) | Apparatus and method for detecting phase and harmonic using fast fourier transform | |
| CN108627694B (en) | Method, device and equipment for detecting voltage frequency of power grid | |
| CN111505375A (en) | Frequency measurement method and device | |
| CN105137198A (en) | Novel dielectric loss measurement method based on Nuttall window - five-point converting FFT | |
| CN109066584A (en) | A kind of capacitor harmonic protection method of high protection act precision | |
| He et al. | A parameterization power data compress using strong trace filter and dynamics | |
| Shi et al. | Adaptive quadrant filter based phase locked loop system | |
| Tan et al. | High‐accurate estimation method of sub‐synchronous and super‐synchronous harmonic parameters on PMU | |
| CN114460363A (en) | Synchronous sampling method and device for alternating current signals and alternating current sampling equipment | |
| CN109342944B (en) | Motor detection method and device | |
| CN114325071A (en) | Rapid high-disturbance-rejection voltage drop identification method for distribution network charging pile | |
| Carugati et al. | Variable, fixed, and hybrid sampling period approach for grid synchronization | |
| Zhang et al. | Fast transient harmonic selective extraction based on modulation-CDSC-SDFT | |
| JP5830941B2 (en) | Phase synchronization detection circuit | |
| CN111711221A (en) | Feedforward selection method in flexible direct current control circuit and related device | |
| Das et al. | Detecting synchrophasors computed over fault/switching transients | |
| Reza et al. | Robust estimation of real-time single-phase grid voltage frequency under distorted conditions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |