CN114325076A - Voltage sag detection method, detection device and processor - Google Patents
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Abstract
The application provides a voltage sag detection method, a voltage sag detection device and a processor. The method comprises the following steps: acquiring a voltage waveform to be detected, wherein the voltage waveform comprises a plurality of periods of sub-voltage waveforms; 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 the periods of the at least two continuous sub-voltage waveforms are continuous, so that the problem of delay caused by long period difference is avoided, filtering treatment is also not needed, 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, the detection time can be shortened, the real-time performance of detection is effectively improved, and the accuracy of detecting the voltage sag is further improved.
Description
Technical Field
The present disclosure relates to the field of voltage sag detection technologies, and in particular, to a voltage sag detection method, a detection apparatus, a computer-readable storage medium, and a processor.
Background
With the development of industrialization and automation, modern enterprises put higher demands on power quality, according to the definition of institute of electrical and electronics engineers IEEE, voltage sag refers to a rapid decrease of an effective value of a supply voltage to below a rated voltage, which is one of the most common power quality problems in a power system, and has become an important social concern, and voltage sag causes more and more loss in industries such as precision manufacturing, semiconductor industry, public service and the like.
How to accurately and quickly measure the level of the effective value of the voltage, judge whether the voltage sag occurs or not, and switch the standby power supply in time is the basis and the premise for voltage compensation or quick switching of the dynamic voltage compensator and the emergency power supply lamp device, and is the premise for guaranteeing the power quality of users and the safe and stable operation of all power consumption equipment under a bus, so the method has very important significance for real-time detection of the voltage sag.
The most common method in the prior art is a method for solving a root mean square value by adopting an instantaneous voltage dq decomposition method and sliding, but the two methods have the problem of low detection accuracy:
in the instantaneous voltage dq decomposition method, a low-pass filter is needed for filtering, so that a large delay inevitably occurs in a time domain, and meanwhile, a certain delay also exists in the output of a phase-locked loop, and the delay is generally more than 5ms, so that the real-time performance is not high, and the detection accuracy is also low;
in the sliding root mean square value solving method, firstly, complex noise and harmonic waves exist in the power grid voltage, if the root mean square is directly calculated, the obtained result error is large, so that misjudgment is possible, secondly, the algorithm has poor real-time performance, at least half of the delay of the fundamental wave period exists, the delay is generally more than 10ms, the real-time performance is not high, and the detection accuracy is low.
Disclosure of Invention
The present application mainly aims to provide a method, a device, a computer-readable storage medium, and a processor for detecting a voltage sag, so as to solve the problem of low accuracy in detecting a voltage sag in the prior art.
According to an aspect of the embodiments of the present invention, there is provided a method for detecting a voltage sag, including: acquiring a voltage waveform to be detected, wherein the voltage waveform comprises a plurality of periods of sub-voltage waveforms; calculating the offset of 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 an offset of the voltage from at least two consecutive sub-voltage waveforms comprises: acquiring amplitudes of N +1 continuous sub-voltage waveforms; determining the instantaneous offset corresponding to the Mth sub-voltage waveform according to the amplitude values, wherein M is more than 1 and less than or equal to N + 1; calculating the average value of the instantaneous offsets corresponding to a plurality of phases of the Q-th sub-voltage waveform to obtain an average offset, wherein Q is more than 1 and less than or equal to N; accumulating the average offsets to obtain accumulated offsets; 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 the plurality of amplitude values, the method further comprises: determining the amplitude of the sub-voltage waveform of the first period as a reference amplitude.
Optionally, determining an instantaneous offset corresponding to the mth sub-voltage waveform according to a plurality of the amplitudes includes: acquiring the difference value of 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; and dividing the difference value by the absolute value of the reference amplitude with the same phase to obtain the instantaneous offset corresponding to the Mth sub-voltage waveform.
Optionally, before calculating an average of the instantaneous offsets corresponding to a plurality of phases of the qth 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.
Optionally, obtaining a 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 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.
Optionally, determining whether a voltage sag occurs in the voltage waveform to be detected according to the offset includes: determining that a voltage sag occurs if the total offset is greater than a predetermined threshold; determining that no voltage sag has occurred if the total offset is less than or equal to the predetermined threshold.
According to another aspect of the embodiments of the present invention, there is also provided a voltage sag detection apparatus, including: the voltage waveform acquisition unit is used for acquiring a voltage waveform to be detected, and the voltage waveform comprises a plurality of periods of sub-voltage waveforms; the calculating unit is used for calculating the offset of 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 embodiments of the present invention, there is also provided a computer-readable storage medium including a stored program, wherein the program executes any one of the methods.
According to still another aspect of the embodiments of the present invention, there is further provided a processor, configured to execute a program, where the program executes any one of the methods.
In the embodiment of the invention, firstly, a voltage waveform to be detected is 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 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 the periods of the at least two continuous sub-voltage waveforms are continuous, so that the problem of delay caused by long period difference is avoided.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:
FIG. 1 shows a schematic flow diagram of a method of detecting a voltage sag according to an embodiment of the present application;
FIG. 2 shows a schematic flow chart for determining a rising edge zero crossing;
FIG. 3 shows a flow chart for determining an instantaneous offset;
FIG. 4 is a schematic diagram of a voltage sag detection device according to an embodiment of the present application; .
FIG. 5 shows a schematic diagram of the acquired voltage waveform to be detected;
FIG. 6 shows a schematic of the resulting instantaneous offset;
FIG. 7 shows a schematic of the resulting average offset;
FIG. 8 shows a schematic of the resulting cumulative offset;
FIG. 9 shows a schematic of the resulting total offset;
fig. 10 is a diagram illustrating a process of determining whether or not a sag occurs in the voltage.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be used. 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. Also, in the specification and 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 mentioned in the background of the invention, in order to solve the above problem, the prior art has low accuracy in detecting the voltage sag, and in an exemplary embodiment of the present application, a method, an apparatus, a computer-readable storage medium, and a processor for detecting the voltage sag are provided.
According to an embodiment of the present application, a method of detecting a voltage sag is provided.
Fig. 1 is a flow chart of a method of detecting a voltage sag according to an embodiment of the present application. As shown in fig. 1, the method comprises the steps of:
step S101, acquiring a voltage waveform to be detected, wherein the voltage waveform comprises a plurality of periods of sub-voltage waveforms;
step S102, calculating voltage offset according to at least two continuous sub-voltage waveforms, wherein the voltage offset is used for representing the amplitude fluctuation condition of the voltage waveforms;
step S103, determining whether a 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 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 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 the periods of the at least two continuous sub-voltage waveforms are continuous, so that the problem of delay caused by long period difference is avoided.
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 different than presented 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 detection accuracy, the sampling frequency should be greater than 25.6kHz/s, i.e., the number of sampling points per period is greater than 512.
In an embodiment of the present application, calculating the offset of the voltage according to at least two consecutive sub-voltage waveforms includes: acquiring amplitudes of N +1 continuous sub-voltage waveforms; determining the instantaneous offset corresponding to the Mth sub-voltage waveform according to the amplitude values, wherein M is more than 1 and less than or equal to N + 1; calculating the average value of the instantaneous offsets corresponding to a plurality of phases of the Q-th sub-voltage waveform to obtain an average offset, wherein Q is more than 1 and less than or equal to N; accumulating a plurality of average offsets to obtain accumulated offsets; 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. In the embodiment, the amplitude of the sub-voltage waveform is calculated for multiple 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, so that the embodiment further ensures that the detection accuracy of the scheme is higher.
In yet another embodiment of the present application, before determining the instantaneous offset corresponding to the mth sub-voltage waveform according to a plurality of the amplitude values, the method further comprises: the amplitude of the above-described sub voltage waveform of the first period is determined as a reference amplitude. In this embodiment, the amplitude of the sub-voltage waveform of the first period can be extracted separately and used as the reference amplitude, so that it is ensured that the instantaneous offset can be determined more accurately according to the reference amplitude.
In a specific embodiment, the rising edge zero-crossing point is further determined according to the acquired voltage waveform, and the specific steps are as follows, as shown in fig. 2, firstly, the amplitude of the nth sampling point is acquired, whether the amplitude of the nth sampling point is greater than or equal to 0 or not is determined, whether the amplitude of the nth-1 sampling point is less than 0 or not is determined in the case that the amplitude of the nth sampling point is greater than or equal to 0 or not is determined, the sampling point with the smaller absolute value of the amplitude of the nth sampling point and the amplitude of the nth-1 sampling point is taken as the zero-crossing point in the case that the amplitude of the nth sampling point is less than 0 or not, in the case that 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 rising edge zero-crossing point of the next period comes, and at the same time, the amplitude of the sub-voltage waveform in the first period is stored in a memory, as a reference amplitude.
In another embodiment of the present application, determining the instantaneous offset corresponding to the mth sub-voltage waveform according to a plurality of the above-mentioned amplitudes comprises: acquiring the difference value of 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; and dividing the difference value by the absolute value of the reference amplitude value in the same phase to obtain the instantaneous offset corresponding to the Mth sub-voltage waveform. In the embodiment, the instantaneous offset can be obtained by calculating the amplitudes of the two continuous sub-voltage waveforms to obtain the calculation result and then calculating the calculation result and the reference amplitude.
Specifically, the instantaneous offset is Δ, which is calculated by the formula
Where u (M) denotes the amplitude of the mth sub-voltage waveform, u (b) denotes the amplitude of the M-1 th sub-voltage waveform in phase, and | u (c) | denotes the reference amplitude.
In yet another specific embodiment, the average offset is
The calculation formula is as follows:
wherein Q represents the Q-th period, N represents the number of sampling points in each period, and since the first period has no instantaneous offset, the first period also has no average offset, the accumulated offset is Σ Δ (N), and the calculation formula is
Wherein
Representing the average offset for the qth period.
In another embodiment of the present application, before calculating an average value of the instantaneous offsets corresponding to a plurality of phases of the qth 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, near the zero-crossing point, since the amplitude of the acquired voltage waveform is very close to 0, a large error occurs when division is performed near the zero-crossing point, and therefore, the instantaneous offsets corresponding to the plurality of sampling points on the left and right of the zero-crossing point of the rising edge and the falling edge are deleted, so as to further ensure that the detection accuracy is high.
Specifically, each of the right and left rising and falling edge zero-crossing points may be discarded
And N represents the number of sampling points in each period, and if the numbers of the sampling points in the front period and the rear period are inconsistent, the values of the sampling points in the front period and the rear period are smaller.
In another specific embodiment, the 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 first period of sub-voltage waveform stored in the memory, obtaining the amplitude of the mth sub-voltage waveform, and turning the rising edge and the falling edge around the zero crossing point
Deleting the corresponding instantaneous offset of each sampling point, acquiring 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, dividing the difference value by the absolute value of the reference amplitude with the same phase to obtain the instantaneous offset corresponding to the Mth sub-voltage waveform, updating the content stored in the register, storing the amplitude of the newly acquired Mth sub-voltage waveform, finishing sampling the amplitude of the Mth sub-voltage waveform, wherein in the process of calculating the instantaneous offset, if the number of sampling points of the M-1 th sub-voltage waveform and the Mth sub-voltage waveform is inconsistent, deleting the redundant sampling points of the Mth sub-voltage waveform under the condition that the number of the sampling points of the M-1 th sub-voltage waveform is less than that of the sampling points of the Mth sub-voltage waveform, the instantaneous offset of the redundant sampling points is not calculated, and whether the redundant sampling points need to be deleted or not does not need to be considered under the condition that the number of the sampling points of the M-1 th sub-voltage waveform is larger than that of the sampling points of the Mth sub-voltage waveform.
In a specific embodiment of the present application, obtaining a 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 includes: and calculating a sum of the cumulative 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 the embodiment, the sum of the accumulated offset and the instantaneous offset corresponding to the (N + 1) th sub-voltage waveform is directly used as the total offset, and the embodiment can more directly and accurately determine the total offset, that is, the total offset of the (N + 1) th voltage waveform can be further accurately obtained, and the detection accuracy of the scheme is further ensured to be higher.
Specifically, the total offset amount is ΔsThe calculation formula is as follows: deltas(QN+M)＝∑Δ(Q)+Δ(M)。
In another specific embodiment of the present application, determining whether a voltage sag occurs in the voltage waveform to be detected according to the offset includes: determining that a voltage sag occurs when the total offset is greater than a predetermined threshold; in the case where the total amount of deviation is less than or equal to the predetermined threshold value, it is determined that no voltage sag has occurred. In the embodiment, whether the voltage sag occurs to the voltage waveform to be detected can be determined more directly and accurately according to the total offset, the detection time is further shortened, and the real-time performance of detection is further improved.
It should be noted that the predetermined threshold may be 10%, and certainly is not limited to 10% above, and may also be any other feasible predetermined threshold, and for the window length of the sub-waveform, it may be
If the window length is smaller, the detection accuracy is also lower, and a person skilled in the art can select an appropriate window length according to actual conditions.
In the above embodiment, the specific detection speed is determined by the window length when the window length is
When the detection speed is 0.625ms, namely after the voltage sag occurs for 0.625ms, the voltage sag can be identified, the detection speed is far higher than that of the prior art, the power quality can be better supervised, the safe operation of the electric equipment is ensured, and in practical application, if the window length is lower than that of the window in length
In this case, the detection speed can be further shortened.
The embodiment of the present application further provides a device for detecting voltage sag, and it should be noted that the device for detecting voltage sag of the embodiment of the present application can be used to execute the method for detecting voltage sag provided by the embodiment of the present application. The voltage sag detection device provided by the embodiment of the present application is described below.
Fig. 4 is a schematic diagram of a voltage sag detection apparatus according to an embodiment of the present application. As shown in fig. 4, the apparatus includes:
an acquiring unit 10, configured to acquire a voltage waveform to be detected, where the voltage waveform includes a plurality of periods of sub-voltage waveforms;
a calculating unit 20, configured to calculate an offset of a voltage according to at least two consecutive sub-voltage waveforms, where the offset of the voltage is used to characterize amplitude fluctuation of the voltage waveforms;
the first determining unit 30 is 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, the voltage waveform includes a plurality of periods of sub-voltage waveforms, the calculating unit calculates an offset of the voltage according to at least two consecutive sub-voltage waveforms, and the first determining unit determines whether the voltage waveform to be detected has a 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 the periods of the at least two continuous sub-voltage waveforms are continuous, so that the problem of delay caused by long period difference is avoided.
In an embodiment of the present application, the calculating unit includes an obtaining module, a first calculating module, a second calculating module, a third calculating module and a fourth calculating module, where the obtaining module is configured to obtain N +1 continuous amplitudes of the sub-voltage waveforms; the first calculation module is used for determining the instantaneous offset corresponding to the Mth sub-voltage waveform according to the amplitude values, wherein M is more than 1 and less than or equal to N + 1; the second calculating module is used for calculating the average value of the instantaneous offsets corresponding to a plurality of phases of the Q-th 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 is used for accumulating a plurality of average offsets to obtain accumulated offsets; the fourth calculating 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. In the embodiment, the amplitude of the sub-voltage waveform is calculated for multiple 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, so that the embodiment further ensures that the detection accuracy of the scheme is higher.
In yet another embodiment of the present application, the apparatus further includes a second determining unit, which is configured to determine the amplitude of the sub-voltage waveform of 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. In this embodiment, the amplitude of the sub-voltage waveform of the first period can be extracted separately and used as the reference amplitude, so that it is ensured that the instantaneous offset can be determined more accurately according to the reference amplitude.
In still another embodiment of the present application, the first calculation module includes a first calculation sub-module and a second calculation sub-module, 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 of the same phase; the second calculating submodule is used for dividing the difference value and the absolute value of the reference amplitude value in the same phase to obtain the instantaneous offset corresponding to the Mth sub-voltage waveform. In the embodiment, the instantaneous offset can be obtained by calculating the amplitudes of the two continuous sub-voltage waveforms to obtain the calculation result and then calculating the calculation result and the reference amplitude.
In another embodiment of the present application, the apparatus further includes a deleting unit, where the deleting unit is configured to delete the instantaneous offsets corresponding to the plurality of sampling points on the right and left of the rising edge and the falling edge zero-crossing point before calculating an average value of the instantaneous offsets corresponding to the plurality of phases of the qth sub-voltage waveform to obtain an average offset. In this embodiment, near the zero-crossing point, since the amplitude of the acquired voltage waveform is very close to 0, a large error occurs when division is performed near the zero-crossing point, and therefore, the instantaneous offsets corresponding to the plurality of sampling points on the left and right of the zero-crossing point of the rising edge and the falling edge are deleted, so as to further ensure that the detection accuracy is high.
In a specific embodiment of the present application, the fourth calculating module includes a third calculating submodule, and the third calculating submodule is configured to calculate a sum of the accumulated offset and the instantaneous offset corresponding to the (N + 1) th sub-voltage waveform, where the sum is the total offset of the (N + 1) th sub-voltage waveform. In the embodiment, the sum of the accumulated offset and the instantaneous offset corresponding to the (N + 1) th sub-voltage waveform is directly used as the total offset, and the embodiment can more directly and accurately determine the total offset, that is, the total offset of the (N + 1) th voltage waveform can be further accurately obtained, and the detection accuracy of the scheme is further ensured to be higher.
In another specific embodiment of the present application, the first determining unit includes a first determining module and a second determining module, and the first determining module is configured to determine that a voltage sag occurs when the total offset is greater than a predetermined threshold; the second determining module is used for determining that no voltage sag occurs under the condition that the total offset is smaller than or equal to the preset threshold. In the embodiment, whether the voltage sag occurs to the voltage waveform to be detected can be determined more directly and accurately according to the total offset, the detection time is further shortened, and the real-time performance of detection is further improved.
The voltage sag detection device comprises a processor and a memory, 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 comprises a kernel, and the kernel calls the corresponding program unit from the memory. The kernel can be set to be 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 in a computer readable medium, Random Access Memory (RAM) and/or nonvolatile memory such as Read Only Memory (ROM) or flash memory (flash RAM), and the memory includes at least one memory chip.
An embodiment of the present invention provides a computer-readable storage medium, on which a program is stored, which, when executed by a processor, implements the above-described voltage sag detection method.
The embodiment of the invention provides a processor, which is used for running a program, wherein the detection method of the voltage sag is executed when the program runs.
The embodiment of the invention provides equipment, which comprises a processor, a memory and a program which is stored on the memory and can run on the processor, wherein when the processor executes the program, at least the following steps are realized:
step S101, acquiring a voltage waveform to be detected, wherein the voltage waveform comprises a plurality of periods of sub-voltage waveforms;
step S102, calculating voltage offset according to at least two continuous sub-voltage waveforms, wherein the voltage offset is used for representing the amplitude fluctuation condition of the voltage waveforms;
step S103, determining whether a voltage sag occurs in the voltage waveform to be detected according to the offset.
The device herein may be a server, a PC, a PAD, a mobile phone, etc.
The present application further provides a computer program product adapted to perform a program of initializing at least the following method steps when executed on a data processing device:
step S101, acquiring a voltage waveform to be detected, wherein the voltage waveform comprises a plurality of periods of sub-voltage waveforms;
step S102, calculating voltage offset according to at least two continuous sub-voltage waveforms, wherein the voltage offset is used for representing the amplitude fluctuation condition of the voltage waveforms;
step S103, determining whether a voltage sag occurs in the voltage waveform to be detected according to the offset.
In order to make the technical solutions of the present application more clearly understood by those skilled in the art, the technical solutions and technical effects of the present application will be described below with reference to specific embodiments.
Examples
The embodiment relates to a method for detecting voltage sag, 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 a sampling frequency of 25.6kHz/s, the number of sampling points in each period is 512, the voltage waveform comprises a plurality of periods of sub-voltage waveforms, as shown in fig. 5, wherein the amplitude of the normal voltage waveform in the first 0.2s is 0.95 times of the rated value, the amplitude of the voltage waveform of 0.3-0.4 s is reduced to 0.92 times of the rated value, the amplitude of the voltage waveform of 0.4-0.6 s is reduced to 0.88 times of the rated value, the amplitude of the voltage waveform of 0.6-0.8 s is reduced to 0.6 times of the rated value, and the amplitude of the voltage waveform of 0.8-1 s is restored to the rated value, wherein the voltage temporarily falls within 0.4-0.8 s;
determining the amplitude of the sub-voltage waveform of the first period as a reference amplitude, and acquiring 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 of the same phase; dividing the difference value by the absolute value of the reference amplitude of the same phase, and deleting the instantaneous offsets corresponding to the plurality of sampling points on the left and right of the zero crossing point of the rising edge and the falling edge to obtain the instantaneous offset corresponding to the Mth sub-voltage waveform, wherein the obtained instantaneous offset is shown in FIG. 6;
calculating the average value of the instantaneous offsets corresponding to a plurality of phases of the Q-th 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 FIG. 7;
accumulating the average offsets to obtain an accumulated offset, which 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 is
N represents the number of sampling points per cycle, N is 512, and the obtained determination result is as follows, as shown in fig. 10, "1" represents that voltage sag occurs, and "0" represents that voltage sag does not occur;
according to the judgment result, it can be determined that when the absolute value of the voltage amplitude is lower than 10% of the rated value, namely, the voltage sag occurs, the voltage sag can be detected within 1.26ms, and the detection speed is greatly improved.
In the above embodiments of the present invention, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.
In the embodiments provided in the present application, it should be understood that the disclosed technology can be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the above-described division of the units may be a logical division, and in actual implementation, there may be another division, for example, multiple units or components may be combined or may be integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, units or modules, and may be in an electrical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit may be stored in a computer-readable storage medium if it is implemented in the form of a software functional unit and sold or used as a separate product. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the above methods according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.
From the above description, it can be seen that the above-described embodiments of the present application achieve the following technical effects:
1) the voltage sag detection method comprises the steps of firstly obtaining a voltage waveform to be detected, wherein the voltage waveform comprises a plurality of periods of sub-voltage waveforms, then calculating voltage offset according to at least two continuous sub-voltage waveforms, and finally determining whether the voltage sag occurs on 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 the periods of the at least two continuous sub-voltage waveforms are continuous, so that the problem of delay caused by long period difference is avoided.
2) The voltage sag detection device comprises an acquisition unit, a calculation unit and a first determination unit, wherein the acquisition unit acquires voltage waveforms to be detected, the voltage waveforms comprise a plurality of periodic sub-voltage waveforms, the calculation unit calculates voltage offset according to at least two continuous sub-voltage waveforms, and the first determination unit determines whether the voltage waveforms to be detected have voltage sag or not according to the offset. In the scheme, at least two continuous sub-voltage waveforms are adopted to calculate the offset of the voltage, and the periods of the at least two continuous sub-voltage waveforms are continuous, so that the problem of delay caused by long period difference is avoided.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (10)
1. A method for detecting a voltage sag, comprising:
acquiring a voltage waveform to be detected, wherein the voltage waveform comprises a plurality of periods of sub-voltage waveforms;
calculating the offset of 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.
2. The method of claim 1, wherein calculating an offset of voltage from at least two consecutive sub-voltage waveforms comprises:
acquiring amplitudes of N +1 continuous sub-voltage waveforms;
determining the instantaneous offset corresponding to the Mth sub-voltage waveform according to the amplitude values, wherein M is more than 1 and less than or equal to N + 1;
calculating the average value of the instantaneous offsets corresponding to a plurality of phases of the Q-th sub-voltage waveform to obtain an average offset, wherein Q is more than 1 and less than or equal to N;
accumulating the average offsets to obtain accumulated offsets;
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.
3. The method of claim 2, wherein prior to determining the instantaneous offset for the mth sub-voltage waveform from the plurality of amplitude values, the method further comprises:
determining the amplitude of the sub-voltage waveform of the first period as a reference amplitude.
4. The method of claim 3, wherein determining an instantaneous offset for the mth sub-voltage waveform from the plurality of amplitude values comprises:
acquiring the difference value of 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;
and dividing the difference value by the absolute value of the reference amplitude with the same phase to obtain the instantaneous offset corresponding to the Mth sub-voltage waveform.
5. The method of claim 3, wherein before averaging the instantaneous offsets for a plurality of phases of the qth 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.
6. The method of claim 3, wherein obtaining the total offset of the N +1 th sub-voltage waveform from the accumulated offset and the instantaneous offset corresponding to the N +1 th 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.
7. The method of claim 6, wherein determining whether a voltage sag occurs in the voltage waveform to be detected based on the offset comprises:
determining that a voltage sag occurs if the total offset is greater than a predetermined threshold;
determining that no voltage sag has occurred if the total offset is less than or equal to the predetermined threshold.
8. A voltage sag detection device, comprising:
the voltage waveform acquisition unit is used for acquiring a voltage waveform to be detected, and the voltage waveform comprises a plurality of periods of sub-voltage waveforms;
the calculating unit is used for calculating the offset of 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;
and the first determining unit is used for determining whether the voltage waveform to be detected has voltage sag according to the offset.
9. 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 7.
10. A processor, characterized in that the processor is configured to run a program, wherein the program when running performs the method of any of claims 1 to 7.
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Citations (16)
| 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 |
| US20160198245A1 (en) * | 2011-08-15 | 2016-07-07 | Geoffrey B. Rhoads | Synchronized metrology in power generation and distribution networks |
| 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 | Alternating current micro-grid voltage distortion degree evaluation method considering fundamental frequency change |
| 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 |
-
2021
- 2021-12-13 CN CN202111518778.8A patent/CN114325076B/en active Active
Patent Citations (16)
| 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 |
| US20160198245A1 (en) * | 2011-08-15 | 2016-07-07 | Geoffrey B. Rhoads | Synchronized metrology in power generation and distribution networks |
| 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 | Alternating current micro-grid voltage distortion degree evaluation method considering fundamental frequency change |
| 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 |
|---|
| MUHAMAD MANSOR 等: "THREE PHASE CONTROL FOR PWM-SWITCHED AUTOTRANSFORMER VOLTAGE-SAG COMPENSATOR BASED ON PHASE ANGLE ANALYSIS", 《JOURNAL OF THEORETICAL AND APPLIED INFORMATION TECHNOLOGY》, vol. 30, no. 2, pages 102 - 108 * |
| 班连庚 等: "特高压交流变压器选相合闸技术研究及工程应用", 《电网技术》, vol. 42, no. 4, pages 1226 - 1233 * |
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