CN110618338B - Electric energy quality transient measurement method, device and equipment - Google Patents
Electric energy quality transient measurement method, device and equipment Download PDFInfo
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Abstract
The application discloses a method, a device and equipment for measuring transient state of electric energy quality, which are used for sampling and converting voltage signals of a circuit to be measured, eliminating the influence of fundamental waves and harmonic waves on the measurement of transient voltage, accurately measuring the peak value and the width of the transient signal and solving the technical problem that the method for measuring the operation transient overvoltage in a power grid is lacked in the prior art.
Description
Technical Field
The application relates to the technical field of transient change detection of power systems, in particular to a method, a device and equipment for transient measurement of power quality.
Background
Transient overvoltage refers to the voltage that when a power system normally operates, the insulation of electrical equipment is under the rated voltage of a power supply, and when lightning strike, operation, fault or parameter configuration and other reasons cause the voltage of some part in the system to rise, the voltage greatly exceeds the value of normal operation.
The significance of transient measurement of a high-voltage power grid is to monitor and control the operating transient overvoltage, and the reasons for operating the transient overvoltage are as follows: the circuit switching-on and switching-off, the fault and fault removal, the switching-off of capacitive current and the switching-off of small or medium inductive current and load sudden change, and the switching-on overvoltage of the no-load circuit in the circuit switching-on and switching-off can reach 3 times of the steady-state voltage to the maximum extent, so that the power grid equipment is damaged, and the monitoring of the operation transient overvoltage in the power grid has practical significance. However, the current unified measurement standard IEC 61000-4-30 for power quality parameters does not provide a specific measurement method for the operation transient overvoltage, which causes difficulty in the measurement of the operation transient overvoltage in the power grid.
Disclosure of Invention
The embodiment of the application provides a method, a device and equipment for measuring the transient state of the power quality, which are used for solving the technical problem that the prior art lacks a method for measuring the transient overvoltage of operation in a power grid.
In view of the above, a first aspect of the present application provides a method for transient measurement of power quality, including the following steps:
101. collecting a voltage signal of a circuit to be tested, wherein the voltage signal comprises at least one cycle voltage, sampling points with the number of first preset sampling points in each cycle and a first sampling value sequence;
102. performing time domain resampling on a first voltage value of a first preset sampling point quantity of the voltage signal in a cycle to obtain a second voltage value of a second preset sampling point quantity;
103. performing FFT (fast Fourier transform) on the second voltage value, and calculating a fundamental peak value and a fundamental phase according to a fundamental component obtained by the FFT to obtain a fundamental sampling value sequence of the second preset sampling point number;
104. interpolating the fundamental wave sampling value sequence into a second sampling value sequence with the first preset sampling point number, and subtracting the first sampling value sequence from the second sampling value sequence to generate a third sampling value sequence without fundamental waves;
105. filtering harmonic waves of the third sampling value sequence to obtain a fourth sampling value sequence;
106. calculating a transient voltage parameter according to the fourth sampling value sequence, wherein the transient voltage parameter comprises: voltage signal peak and voltage signal width.
Preferably, step 106 specifically includes:
1061. searching zero-crossing points of the fourth sampling value sequence, wherein every two zero-crossing points form a group;
1062. acquiring a sampling point value after the first zero-crossing point, a maximum point peak value sampling point value and a sampling point value before the second zero-crossing point of each group of zero-crossing points;
1063. and taking a group of zero-crossing points where the maximum value is obtained from the maximum point peak value sampling point numerical values as a typical data group, and calculating transient voltage parameters corresponding to the typical data group according to the fundamental wave peak value and the first zero-crossing point post-sampling point numerical value, the maximum point peak value sampling point numerical value and the second zero-crossing point pre-sampling point numerical value of the typical data group.
Preferably, step 105 specifically comprises:
filtering harmonic waves of the third sampling value sequence according to a preset filtering formula to obtain a fourth sampling value sequence, wherein the preset filtering formula is as follows:
where UF' is the fourth sample sequence, UF [ i]Is a third sample value sequence, i is a sample point, U1Is the fundamental peak-to-peak value.
Preferably, the transient voltage parameter is calculated by the following formula:
Up＝(Yv+0.05U1)；
where κ is the time interval between two sampling points, UpIs the peak value of the voltage signal, t is the width of the voltage signal, YvIs the maximum peak sampling point value, XvIs the value of the first post-zero-crossing sample point, ZvThe value of a sampling point before the second zero-crossing point, Y is a maximum point peak value sampling point, X is a sampling point after the first zero-crossing point, and Z is a sampling point before the second zero-crossing point.
The second aspect of the present application provides an electric energy quality transient measurement device, comprising the following modules:
the circuit comprises an acquisition module, a detection module and a control module, wherein the acquisition module is used for acquiring a voltage signal of a circuit to be detected, and the voltage signal comprises at least one cycle voltage, sampling points with the number of first preset sampling points in each cycle and a first sampling value sequence;
the resampling module is used for resampling time domains of first voltage values of a first preset sampling point quantity of the voltage signal in a cycle to obtain second voltage values of a second preset sampling point quantity;
the first conversion module is used for carrying out FFT conversion on the second voltage value, calculating a fundamental wave peak value and a fundamental wave phase according to a fundamental wave component obtained by the FFT conversion, and obtaining a fundamental wave sampling value sequence of the second preset sampling point quantity;
the second conversion module is used for interpolating the fundamental wave sampling value sequence into a second sampling value sequence with the first preset sampling point number, subtracting the first sampling value sequence from the second sampling value sequence and generating a third sampling value sequence without fundamental waves;
the harmonic processing module is used for filtering harmonic processing of the third sampling value sequence to obtain a fourth sampling value sequence;
a transient parameter module, configured to calculate a transient voltage parameter according to the fourth sample value sequence, where the transient voltage parameter includes: voltage signal peak and voltage signal width.
Preferably, the transient parameter module specifically includes:
the searching submodule is used for searching the zero-crossing points of the fourth sampling value sequence, and every two zero-crossing points form a group;
the acquisition submodule is used for acquiring a sampling point value after the first zero-crossing point, a maximum point peak value sampling point value and a sampling point value before the second zero-crossing point of each group of zero-crossing points;
and the calculation submodule is used for taking a group of zero-crossing points where the maximum value of the maximum point peak value sampling point value is obtained as a typical data set, and calculating the transient voltage parameter corresponding to the typical data set according to the fundamental wave peak value and the first zero-crossing point post-sampling point value, the maximum point peak value sampling point value and the second zero-crossing point pre-sampling point value of the typical data set.
Preferably, the harmonic processing module is specifically configured to:
filtering harmonic waves of the third sampling value sequence according to a preset filtering formula to obtain a fourth sampling value sequence, wherein the preset filtering formula is as follows:
where UF' is the fourth sample sequence, UF [ i]Is a third sample value sequence, i is a sample point, U1Is the fundamental peak-to-peak value.
A third aspect of the present application provides a power quality transient measurement device, configured to perform any one of the power quality transient measurement methods according to the first aspect, including a voltage dividing resistor, an ADC sampling chip, and a microprocessor chip, which are connected in sequence;
the voltage dividing resistor and the ADC sampling chip are used for acquiring a voltage signal of a circuit to be tested and sampling the voltage signal;
and the micro-processing chip is used for carrying out signal conversion on the sampling signal sent by the ADC chip and calculating the transient voltage parameter of the circuit to be tested.
Preferably, the voltage dividing resistor is a cylindrical precision resistor of 5 ppm.
Preferably, the 0 kHz-5 kHz signal of the ADC chip is accurately within +/-0.02%, the attenuation of the 7kHz-700kHz signal is more than 100db, and the sampling rate is 12.8K.
According to the technical scheme, the embodiment of the application has the following advantages:
the application provides a transient measurement method for power quality, which comprises the following steps: 101. collecting a voltage signal of a circuit to be tested, wherein the voltage signal comprises at least one cycle voltage, sampling points with the number of first preset sampling points in each cycle and a first sampling value sequence; 102. performing time domain resampling on a first voltage value of a first preset sampling point quantity of a voltage signal in a cycle to obtain a second voltage value of a second preset sampling point quantity; 103. performing FFT (fast Fourier transform) on the second voltage value, and calculating a fundamental peak value and a fundamental phase according to a fundamental component obtained by the FFT to obtain a fundamental sampling value sequence of a second preset sampling point number; 104. interpolating the fundamental wave sampling value sequence into a second sampling value sequence with the first preset sampling point number, and subtracting the first sampling value sequence from the second sampling value sequence to generate a third sampling value sequence without fundamental waves; 105. filtering harmonic waves of the third sampling value sequence to obtain a fourth sampling value sequence; 106. calculating a transient voltage parameter according to the fourth sampling value sequence, wherein the transient voltage parameter comprises: voltage signal peak and voltage signal width. According to the transient measurement method for the power quality, the voltage signal of the circuit to be measured is sampled and subjected to signal conversion, the influence of fundamental waves and harmonic waves on transient voltage measurement is eliminated, the peak value and the width of the transient signal can be accurately measured, and the technical problem that a method for measuring the operation transient overvoltage in a power grid is lacked in the prior art is solved.
Drawings
Fig. 1 is a schematic flow chart of an embodiment of a transient measurement method for power quality provided in the present application;
fig. 2 is a schematic flow chart of another embodiment of a transient measurement method for power quality provided in the present application;
fig. 3 is a schematic structural diagram of an embodiment of an apparatus for transient measurement of power quality provided in the present application;
fig. 4 is a schematic structural diagram of an embodiment of a transient measurement device for power quality provided by the present application.
Detailed Description
In order to make the technical solutions of the present application better understood, 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 a part of the embodiments of the present application, and not all of the 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.
For ease of understanding, referring to fig. 1, an embodiment of a method for transient measurement of power quality provided herein includes:
It should be noted that, in this embodiment of the present application, a to-be-tested circuit samples a voltage of one cycle, which may be a voltage of multiple cycles, and only one cycle is needed to meet the measurement requirement, so that in this embodiment of the present application, only a voltage signal of one cycle needs to be collected, the number of sampling points is M, and the sequence of the first sampling value is Pr.
102, resampling a time domain of a first voltage value of a first preset sampling point quantity of a voltage signal in a cycle to obtain a second voltage value of a second preset sampling point quantity.
It should be noted that, time-domain resampling is performed on the sampled voltage values of M points through an interpolation formula to obtain voltage values of N points, where the interpolation formula may be a sampling interpolation formula in the prior art, and details are not repeated in this embodiment of the application.
And 103, performing FFT (fast Fourier transform) on the second voltage value, and calculating a fundamental peak value and a fundamental phase according to a fundamental component obtained by the FFT to obtain a fundamental sampling value sequence with a second preset sampling point number.
In this embodiment, the second voltage value obtained in step 102, that is, the voltage value at the N point, is subjected to FFT (Fast Fourier Transform) to obtain a fundamental component: ure1 (voltage real part) and Uim1 (voltage imaginary part), and the fundamental peak value U is calculated according to the fundamental component1And fundamental wave phase
According to the fundamental peak-to-peak value U1And fundamental wave phase
Generating a fundamental wave sampling value sequence Fd with the number of sampling points Nn：
And 104, interpolating the fundamental wave sampling value sequence into a second sampling value sequence with the first preset sampling point number, and subtracting the first sampling value sequence from the second sampling value sequence to generate a third sampling value sequence without the fundamental wave.
It should be noted that, in the embodiment of the present application, after obtaining the fundamental wave sample value sequence, the fundamental wave sample value sequence Fd is obtainednSecond sampling value interpolated into M pointsSequence FdmThen the first sampling value sequence is Pr minus the second sampling value sequence FdmGenerating a third sampling value sequence UF without fundamental wave:
UF＝Pr-Fdm。
and 105, filtering harmonic waves of the third sampling value sequence to obtain a fourth sampling value sequence.
It should be noted that, in order to shield harmonic influence, in the embodiment of the present application, harmonic filtering processing needs to be performed on the third sampling value sequence, so as to obtain a fourth sampling value sequence after harmonic filtering.
It should be noted that in the embodiment of the present application, the signal peak value and the signal width of the instantaneous voltage are calculated according to the fundamental wave and the harmonic fourth sampling value sequence, and then the process returns to step 101 to sample the voltage signal again.
According to the transient measurement method for the power quality, the voltage signal of the circuit to be measured is sampled and subjected to signal conversion, the influence of fundamental waves and harmonic waves on transient voltage measurement is eliminated, the peak value and the width of the transient signal can be accurately measured, and the technical problem that a method for measuring the operation transient overvoltage in a power grid is lacked in the prior art is solved.
For ease of understanding, referring to fig. 2, the present application provides another embodiment of a method for transient measurement of power quality, comprising:
And 203, performing FFT on the second voltage value, and calculating a fundamental peak value and a fundamental phase according to a fundamental component obtained by the FFT to obtain a fundamental sampling value sequence of a second preset sampling point number.
And 204, interpolating the fundamental wave sampling value sequence into a second sampling value sequence with the first preset sampling point number, and subtracting the first sampling value sequence from the second sampling value sequence to generate a third sampling value sequence without the fundamental wave.
It should be noted that steps 201 to 204 in this embodiment are the same as steps 101 to 104 in the previous embodiment, and are not described herein again.
where UF' is the fourth sample sequence, UF [ i]Is a third sample value sequence, i is a sample point, U1Is the fundamental peak-to-peak value.
It should be noted that 5% of fundamental peak value U is used in the embodiment of the present application1The fourth sample value sequence UF' is obtained as a threshold mask for harmonic effects.
And step 206, searching for zero-crossing points of the fourth sampling value sequence, wherein every two zero-crossing points form a group.
It should be noted that, in the embodiment of the present application, after the fourth sample value sequence is obtained, zero-crossing points of the fourth sample value sequence need to be searched, and every two zero-crossing points are divided into a group, where each group is a transient signal.
And step 207, acquiring the value of a sampling point after the first zero-crossing point, the value of a sampling point at the peak of the maximum point and the value of a sampling point before the second zero-crossing point of each group of zero-crossing points.
It should be noted that after all the zero-crossing points are found, the sampling point X after the first zero-crossing point, the sampling point Y of the maximum peak value, and the sampling point Z before the second zero-crossing point of each group are found, and the corresponding sampled values Xv, Yv, and Zv are obtained respectively.
And 208, taking a group of zero-crossing points where the maximum point peak value sampling point value is the maximum value as a typical data group, and calculating the transient voltage parameter corresponding to the typical data group according to the fundamental wave peak value and the value of the sampling point after the first zero-crossing point, the value of the maximum point peak value sampling point and the value of the sampling point before the second zero-crossing point of the typical data group.
Further, the transient voltage parameter is calculated by the following formula:
Up＝(Yv+0.05U1)；
where κ is the time interval between two sampling points, UpIs the peak value of the voltage signal, t is the width of the voltage signal, YvIs the maximum peak sampling point value, XvIs the value of the first post-zero-crossing sample point, ZvThe value of a sampling point before the second zero-crossing point, Y is a maximum point peak value sampling point, X is a sampling point after the first zero-crossing point, and Z is a sampling point before the second zero-crossing point.
It should be noted that, comparing each group of data in step 207, selecting a group with the maximum peak sampling point value Yv as a typical data group, and calculating the peak value and the peak value of the transient signal corresponding to the typical data group, and the voltage signal peak value UpComprises the following steps:
Up＝(Yv+0.05U1)；
the voltage signal width t is:
in the embodiment of the application, after interpolation is carried out on a voltage signal sequence of a cycle, fundamental wave components are decomposed through FFT (fast Fourier transform), fundamental wave sequences are regenerated, the difference value of the fundamental wave sequences is converted into fundamental wave sequences with the same number of points as the original voltage signal sequence, the fundamental wave sequence is subtracted from the original voltage signal sequence to obtain a sequence UF without the fundamental wave components, and the sequence UF is based on the condition that the harmonic content of a high-voltage power grid is lower than that of the high-voltage
Removing harmonic influence, obtaining a sequence UF' without fundamental wave and harmonic, and calculating transient parameters.
For ease of understanding, referring to fig. 3, an embodiment of an apparatus for transient measurement of power quality is provided herein, comprising the following modules:
the acquisition module 301 is configured to acquire a voltage signal of a circuit to be detected, where the voltage signal includes a voltage of at least one cycle, sampling points of a first preset sampling point number in each cycle, and a first sampling value sequence.
The resampling module 302 is configured to perform time domain resampling on a first voltage value of a first preset number of sampling points of a voltage signal within a cycle, so as to obtain a second voltage value of a second preset number of sampling points.
The first transform module 303 is configured to perform FFT on the second voltage value, calculate a fundamental peak value and a fundamental phase according to a fundamental component obtained by the FFT, and obtain a fundamental sample value sequence of a second preset sample point number.
And the second transformation module 304 is configured to interpolate the fundamental wave sample value sequence into a second sample value sequence of the first preset sample number, and subtract the first sample value sequence from the second sample value sequence to generate a third sample value sequence without the fundamental wave.
And the harmonic processing module 305 is configured to filter out harmonic processing on the third sampling value sequence to obtain a fourth sampling value sequence.
A transient parameter module 306, configured to calculate a transient voltage parameter according to the fourth sample value sequence, where the transient voltage parameter includes: voltage signal peak and voltage signal width.
Further, the transient parameter module 306 specifically includes:
the searching submodule 3061 is configured to search for zero-crossing points of the fourth sequence of sample values, where every two zero-crossing points are in one group.
The obtaining sub-module 3062 is configured to obtain a value of a sampling point after the first zero-crossing point, a value of a sampling point at the peak of the maximum point, and a value of a sampling point before the second zero-crossing point in each group of zero-crossing points.
The calculating submodule 3063 is configured to use a group of zero-crossing points where the maximum value is obtained from the maximum point peak value sampling point value as a typical data set, and calculate a transient voltage parameter corresponding to the typical data set according to the fundamental wave peak value and the sampling point value after the first zero-crossing point, the maximum point peak value sampling point value and the sampling point value before the second zero-crossing point of the typical data set.
Further, the harmonic processing module 305 is specifically configured to:
filtering harmonic waves of the third sampling value sequence according to a preset filtering formula to obtain a fourth sampling value sequence, wherein the preset filtering formula is as follows:
where UF' is the fourth sample sequence, UF [ i]Is a third sample value sequence, i is a sample point, U1Is the fundamental peak-to-peak value.
For easy understanding, please refer to fig. 4, an embodiment of a power quality transient measurement apparatus is provided in the present application, for performing the power quality transient measurement method in the foregoing power quality transient measurement method embodiment, including a voltage divider resistor, an ADC sampling chip and a microprocessor chip connected in sequence;
the voltage dividing resistor and the ADC sampling chip are used for acquiring a voltage signal of the circuit to be tested and sampling the voltage signal;
the micro-processing chip is used for carrying out signal conversion on the sampling signal sent by the ADC chip and calculating transient voltage parameters of the circuit to be tested.
Furthermore, the micro-processing chip adopts a DSP chip.
Further, the voltage dividing resistance was a cylindrical precision resistance of 5 ppm.
Furthermore, the 0 kHz-5 kHz signal of the ADC chip is accurately within +/-0.02%, the attenuation of the 7kHz-700kHz signal is more than 100db, and the sampling rate is 12.8K.
In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or 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, devices or units, and may be in an electrical, mechanical 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 network 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 application 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, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in 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 method according to the embodiments of the present application. And the aforementioned storage medium includes: a U disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.
Claims (10)
1. A power quality transient measurement method is characterized by comprising the following steps:
101. collecting a voltage signal of a circuit to be tested, wherein the voltage signal comprises at least one cycle voltage, sampling points with the number of first preset sampling points in each cycle and a first sampling value sequence;
102. performing time domain resampling on a first voltage value of a first preset sampling point quantity of the voltage signal in a cycle to obtain a second voltage value of a second preset sampling point quantity;
103. performing FFT (fast Fourier transform) on the second voltage value, and calculating a fundamental peak value and a fundamental phase according to a fundamental component obtained by the FFT to obtain a fundamental sampling value sequence of the second preset sampling point number;
104. interpolating the fundamental wave sampling value sequence into a second sampling value sequence with the first preset sampling point number, and subtracting the first sampling value sequence from the second sampling value sequence to generate a third sampling value sequence without fundamental waves;
105. filtering harmonic waves of the third sampling value sequence to obtain a fourth sampling value sequence;
106. calculating a transient voltage parameter according to the fourth sampling value sequence, wherein the transient voltage parameter comprises: voltage signal peak and voltage signal width.
2. The transient measurement method of power quality according to claim 1, wherein step 106 specifically comprises:
1061. searching zero-crossing points of the fourth sampling value sequence, wherein every two zero-crossing points form a group;
1062. acquiring a sampling point value after the first zero-crossing point, a maximum point peak value sampling point value and a sampling point value before the second zero-crossing point of each group of zero-crossing points;
1063. and taking a group of zero-crossing points where the maximum value is obtained from the maximum point peak value sampling point numerical values as a typical data group, and calculating transient voltage parameters corresponding to the typical data group according to the fundamental wave peak value and the first zero-crossing point post-sampling point numerical value, the maximum point peak value sampling point numerical value and the second zero-crossing point pre-sampling point numerical value of the typical data group.
3. The transient measurement method of power quality according to claim 1, wherein step 105 specifically comprises:
filtering harmonic waves of the third sampling value sequence according to a preset filtering formula to obtain a fourth sampling value sequence, wherein the preset filtering formula is as follows:
where UF' is the fourth sample sequence, UF [ i]Is a third sample value sequence, i is a sample point, U1Is the fundamental peak-to-peak value.
4. The transient measurement method of power quality according to claim 2, wherein the transient voltage parameter is calculated by the formula:
Up＝(Yv+0.05U1)；
where κ is the time interval between two sampling points, UpIs the peak value of the voltage signal, t is the width of the voltage signal, YvIs the maximum peak sampling point value, XvIs the value of the first post-zero-crossing sample point, ZvIs the value of the sampling point before the second zero crossing point, Y is the sampling point of the maximum point peak value, X is the sampling point after the first zero crossing point, Z is the sampling point before the second zero crossing point, U1Is the fundamental peak-to-peak value.
5. An electric energy quality transient measurement device, characterized by comprising the following modules:
the circuit comprises an acquisition module, a detection module and a control module, wherein the acquisition module is used for acquiring a voltage signal of a circuit to be detected, and the voltage signal comprises at least one cycle voltage, sampling points with the number of first preset sampling points in each cycle and a first sampling value sequence;
the resampling module is used for resampling time domains of first voltage values of a first preset sampling point quantity of the voltage signal in a cycle to obtain second voltage values of a second preset sampling point quantity;
the first conversion module is used for carrying out FFT conversion on the second voltage value, calculating a fundamental wave peak value and a fundamental wave phase according to a fundamental wave component obtained by the FFT conversion, and obtaining a fundamental wave sampling value sequence of the second preset sampling point quantity;
the second conversion module is used for interpolating the fundamental wave sampling value sequence into a second sampling value sequence with the first preset sampling point number, subtracting the first sampling value sequence from the second sampling value sequence and generating a third sampling value sequence without fundamental waves;
the harmonic processing module is used for filtering harmonic processing of the third sampling value sequence to obtain a fourth sampling value sequence;
a transient parameter module, configured to calculate a transient voltage parameter according to the fourth sample value sequence, where the transient voltage parameter includes: voltage signal peak and voltage signal width.
6. The transient measurement device of power quality as claimed in claim 5, wherein the transient parameter module specifically comprises:
the searching submodule is used for searching the zero-crossing points of the fourth sampling value sequence, and every two zero-crossing points form a group;
the acquisition submodule is used for acquiring a sampling point value after the first zero-crossing point, a maximum point peak value sampling point value and a sampling point value before the second zero-crossing point of each group of zero-crossing points;
and the calculation submodule is used for taking a group of zero-crossing points where the maximum value of the maximum point peak value sampling point value is obtained as a typical data set, and calculating the transient voltage parameter corresponding to the typical data set according to the fundamental wave peak value and the first zero-crossing point post-sampling point value, the maximum point peak value sampling point value and the second zero-crossing point pre-sampling point value of the typical data set.
7. The power quality transient measurement device of claim 5, wherein the harmonic processing module is specifically configured to:
filtering harmonic waves of the third sampling value sequence according to a preset filtering formula to obtain a fourth sampling value sequence, wherein the preset filtering formula is as follows:
where UF' is the fourth sample sequence, UF [ i]Is a third sample value sequence, i is a sample point, U1Is the fundamental peak-to-peak value.
8. A power quality transient measurement device for performing the power quality transient measurement method according to any one of claims 1 to 4, comprising a voltage dividing resistor, an ADC sampling chip and a microprocessor chip connected in sequence;
the voltage dividing resistor and the ADC sampling chip are used for acquiring a voltage signal of a circuit to be tested and sampling the voltage signal;
and the micro-processing chip is used for carrying out signal conversion on the sampling signal sent by the ADC chip and calculating the transient voltage parameter of the circuit to be tested.
9. The apparatus of claim 8 wherein the voltage divider resistance is a cylindrical precision resistance of 5 ppm.
10. The power quality transient measurement device of claim 8, wherein the ADC chip has a 0 kHz-5 kHz signal accuracy within ± 0.02%, a 7kHz-700kHz signal attenuation greater than 100db, and a sampling rate of 12.8K.
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| CN102478601A (en) * | 2010-11-23 | 2012-05-30 | 上海市电力公司 | Harmonic calculation method for 64 sampling points of power quality |
| CN105116245B (en) * | 2015-07-21 | 2018-04-13 | 恒电科技有限公司 | A kind of electric energy quality on-line monitoring device based on Ethernet |
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