Method and system for accurately measuring dynamic response of power load

Abstract

The invention provides a method and system for accurately measuring dynamic response of a power supply load. The method comprises the following steps: acquiring waveform original data measured by the dynamic response of the power supply load; filtering the waveform original data to obtain first waveform data; calculating a high value and a low value of the first waveform data, the high value and the low value being determined based on the amount of data falling into a plurality of equally spaced groups in the first waveform data; determining corresponding feature points according to the first waveform data, the high value and the low value; fitting according to the high value, the low value and the feature point to obtain an output voltage error curve; and constructing an output response waveform based on a difference value between the first waveform data and a corresponding data point in the output voltage error curve, and measuring a load according to the output response waveform to obtain a measurement result. According to the invention, the measurement accuracy and consistency can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of power supply technology applications, and in particular to a method and system for accurately measuring the dynamic response of a power supply load. Background Art

[0002] In the application of power supply products, load changes may occur, causing transient changes in output current. In order to determine whether the power supply product can maintain a stable output voltage in such situations, it is necessary to test the output response characteristics (including amplitude and time) of the product when the load current changes instantaneously, and the test results should remain within the specified range. However, in the actual test process, due to the limitations of the power supply output structure, test environment, and test fixture structure, when the load current jumps, the output voltage of the power supply product will change accordingly, affecting the accuracy and consistency of the measurement results. Summary of the invention

[0003] In view of the above problems existing in the prior art, the present invention proposes a method and system for accurately measuring the dynamic response of a power supply load, mainly to solve the problem of poor accuracy and consistency of the existing measurement method.

[0004] In order to achieve the above purpose and other purposes, the technical solution adopted by the present invention is as follows.

[0005] The present application provides a method for accurately measuring the dynamic response of a power supply load, comprising: obtaining waveform raw data for measuring the dynamic response of a power supply load; filtering the waveform raw data to obtain first waveform data; calculating a high value and a low value of the first waveform data, wherein the high value and the low value are determined based on the amount of data falling into a plurality of equally spaced groups in the first waveform data; determining corresponding feature points according to the first waveform data and the high value and the low value; fitting an output voltage error curve according to the high value, the low value and the feature point; constructing an output response waveform based on the difference between the first waveform data and the corresponding data points in the output voltage error curve, so as to measure the load according to the output response waveform and obtain a measurement result.

[0006] In one embodiment of the present application, the step of calculating the high value and the low value of the first waveform data includes: dividing the first waveform data into a preset number of data groups with the maximum value and the minimum value of the voltage in the first waveform data as boundaries, and counting the number of the first waveform data falling into each of the data groups; determining the high value and the low value of the first waveform data based on the interval of the two data groups with the highest statistical frequency in each of the data groups.

[0007] In one embodiment of the present application, the high value and the low value of the first waveform data are determined according to the interval in which the two data groups with the highest statistical frequency in each of the data groups are located, including: the interval boundary of the two data groups with the highest statistical frequency; calculating the corresponding interval median based on the interval boundary, and taking the larger median as the high value and the smaller median as the low value.

[0008] In one embodiment of the present application, the step of determining the corresponding characteristic points based on the first waveform data and the high value and the low value includes: taking the inflection point of the output voltage change of the first waveform data at the beginning of the load jump as the first characteristic point; taking the horizontal coordinate of the first characteristic point and the vertical coordinate of the low value as the second characteristic point; on the basis of the second characteristic point, taking the product of the load jump time and the oscilloscope sampling rate plus the horizontal coordinate of the first characteristic point as the horizontal coordinate of the third characteristic point, and taking the vertical coordinate of the second characteristic point as the vertical coordinate of the third characteristic point.

[0009] In one embodiment of the present application, the step of taking the output voltage change inflection point of the first waveform data at the beginning of the load jump as the first characteristic point includes: taking each voltage data point in the first waveform data as a reference, taking preset intervals of equal length forward and backward respectively, wherein the first voltage data point is extended forward by the length of the preset interval, and the extended data is equal to the data of the first voltage data point, and the last voltage data point is extended backward by the length of the preset interval, and the extended data is equal to the data of the last voltage data point; calculating the ratio of the variance of the backward preset interval and the forward preset interval of each voltage data point as discrete data; comparing the discrete data with the preset threshold in turn, and taking the first discrete data greater than the preset threshold as the coordinates of the first characteristic point.

[0010] In one embodiment of the present application, the step of fitting the output voltage error curve according to the high value, the low value and the characteristic point includes: taking the high value as the inflection point of the output voltage error curve, connecting the first characteristic point with the third characteristic point, and taking the low value as the end line to form the output voltage error curve.

[0011] In one embodiment of the present application, based on the difference between the first waveform data and the corresponding data points in the output voltage error curve, the step of constructing an output response waveform includes: subtracting the vertical coordinate of the first waveform data from the vertical coordinate of the output voltage error curve, while keeping the horizontal coordinate unchanged, to obtain the output response waveform.

[0012] The present application also provides a system for accurately measuring the dynamic response of a power supply load, comprising: a sampling module, used to obtain waveform raw data for measuring the dynamic response of a power supply load; a filtering module, used to filter the waveform raw data to obtain first waveform data; a waveform analysis module, used to calculate the high value and the low value of the first waveform data, wherein the high value and the low value are determined based on the amount of data falling into a plurality of equally spaced groups in the first waveform data; a feature calculation module, used to determine corresponding feature points based on the first waveform data and the high value and the low value; an error curve fitting module, used to obtain an output voltage error curve based on the high value, the low value and the feature point fitting; and a response measurement module, used to construct an output response waveform based on the difference between the first waveform data and the corresponding data points in the output voltage error curve, so as to measure the load according to the output response waveform and obtain a measurement result.

[0013] As described above, the present application provides a method and system for accurately measuring the dynamic response of a power supply load, which has the following beneficial effects.

[0014] Without using a four-wire structure test fixture, the present application calculates the output voltage error curve data points by filtering, extracting, and analyzing the original test results. By calculating the difference between the filtered waveform data points and the output voltage error curve waveform data points, the curve fitted by the difference data points is the accurate output response waveform, thereby accurately measuring the load dynamic response related parameters, which can effectively improve the accuracy and consistency of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the load jump output waveform when there is no fixture contact resistance (taking no-load to full-load as an example).

[0016] Figure 2 This is the output voltage error waveform caused by the fixture contact resistance when the load changes (taking no-load to full-load as an example).

[0017] Figure 3 This is the load jump output waveform when there is fixture contact resistance (taking no-load to full-load as an example).

[0018] Figure 4 Schematic diagram of a flow chart of a method for accurately measuring a dynamic response of a power load in an embodiment of the present application.

[0019] Figure 5 This is a flow chart of extracting and analyzing waveform data in one embodiment of the present application.

[0020] Figure 6 Schematic diagram of the filtered waveform, characteristic points and fitted waveform in one embodiment of the present application.

[0021] Figure 7 Schematic diagram of the frequency of waveform data after filtering in one embodiment of the present application.

[0022] Figure 8 This is a fitting curve of discrete data points of the filtered waveform in one embodiment of the present application. DETAILED DESCRIPTION

[0023] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0024] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0025] The inventors have found that:

[0026] In actual testing, in order to reduce the measurement error caused by the contact resistance of the test fixture, a four-wire structure (Kelvin structure) fixture is often used to measure the dynamic response of the load. The dynamic response waveform is as follows: Figure 1 However, due to hardware factors such as the output structure of high-power miniaturized power supplies and lead length or environmental factors such as online testing, some test fixtures are limited and cannot adopt a four-wire structure. As the number of times the fixture is used increases, the clamping force weakens, the contact point deforms, and the fixture contact resistance increases. When the load current jumps, the output voltage of the product changes due to the voltage drop caused by the fixture contact resistance (such as Figure 2 ), which in turn affects the measurement results of the load dynamic response (such as Figure 3 ), it is difficult to ensure the accuracy and consistency of the measurement results. Therefore, a method for accurately measuring the dynamic response of power supply load without using a four-wire test fixture is realized, which can improve the test accuracy and consistency of the dynamic response of the load, and has high innovation and practical application significance.

[0027] The specific implementation process of the method and system for accurately measuring the dynamic response of a power supply load of the present application is described in detail below in conjunction with specific embodiments.

[0028] See also Figure 4 , Figure 4The method of accurately measuring the dynamic response of a power supply load in an embodiment of the present application is a flow chart. The method of the embodiment of the present application includes the following steps:

[0029] Step S400, obtaining waveform raw data of power load dynamic response measurement;

[0030] In one embodiment, the load dynamic response waveform of the power supply product may be sampled by an oscilloscope to obtain the original waveform data (ie, the original result).

[0031] Step S410, filtering the waveform original data to obtain first waveform data;

[0032] In one embodiment, the waveform raw data may be filtered by a filter to remove interference and noise to obtain the first waveform data, that is, Figure 6 The waveform L1, L1 shown is used to characterize the dynamic response waveform affected by the fixture contact resistance.

[0033] Step S420, calculating a high value and a low value of the first waveform data, wherein the high value and the low value are determined based on the amount of data falling into a plurality of equally spaced groups in the first waveform data.

[0034] In one embodiment, the step of calculating the high value and the low value of the first waveform data includes: dividing the first waveform data into a preset number of data groups with the maximum value and the minimum value of the voltage in the first waveform data as the boundary, and counting the number of the first waveform data falling into each of the data groups; determining the high value and the low value of the first waveform data according to the interval where the two data groups with the highest statistical frequency in each of the data groups are located. The specific steps for calculating the high value and the low value are as follows Figure 5 As shown, firstly, all voltage values ​​in the waveform data (i.e., the first waveform data) are extracted, and the maximum and minimum values ​​in the data are counted; then, a fixed number of data groups are divided based on the maximum and minimum values ​​as boundaries (the specific number of data groups can be set and adjusted according to actual application requirements, and there is no restriction here). During the grouping process, the boundary condition (i.e., boundary value) of each group is calculated based on the maximum value, minimum value and number of groups, and then the number of data points in the first waveform data that fall into the corresponding data group is counted.

[0035] The high value and the low value of the first waveform data are determined according to the interval where the two data groups with the highest statistical frequency in each of the data groups are located, including: the interval boundary of the two data groups with the highest statistical frequency; calculating the corresponding interval median based on the interval boundary, and taking the larger median as the high value and the smaller median as the low value.

[0036] The specific process can be expressed as follows:

[0037] First, extract the voltage value and time base value of waveform L1, and obtain the maximum and minimum values ​​of the voltage value. Then, divide the maximum and minimum value range into N intervals with equal spacing (the N value can be a fixed value or set according to the test accuracy), and calculate the boundary value of each interval. Finally, compare the acquired data with each group one by one, and count the number of data in each group. The statistical results are as follows: Figure 7 As shown, the interval boundary values ​​y1H, y1L and y2H, y2L of the two voltage values ​​with the highest frequency are statistically analyzed, and the high value y1=(y1H+y1L) / 2 and the low value y2=(y2H+y2L) / 2 are returned.

[0038] Step S430: determining corresponding feature points according to the first waveform data and the high value and the low value.

[0039] In one embodiment, the step of determining the corresponding characteristic points based on the first waveform data and the high value and the low value includes: taking the inflection point of the output voltage change of the first waveform data at the beginning of the load jump as the first characteristic point; taking the horizontal coordinate of the first characteristic point and the vertical coordinate of the low value as the second characteristic point; on the basis of the second characteristic point, taking the product of the load jump time and the oscilloscope sampling rate plus the horizontal coordinate of the first characteristic point as the horizontal coordinate of the third characteristic point, and taking the vertical coordinate of the second characteristic point as the vertical coordinate of the third characteristic point.

[0040] Specifically, according to the set load jump time Δt and oscilloscope sampling rate f; the inflection point of the product output voltage change at the beginning of the load jump is taken as the first characteristic point P1 (x1, y1); x1 and the low value y2 of the first characteristic point P1 are taken as the second characteristic point P2 (x1, y2); on the basis of the second characteristic point P2, x1+Δt*f and the low value y2 are taken as the third characteristic point P3 (x1+Δt*f, y2).

[0041] In one embodiment, the step of taking the output voltage change inflection point of the first waveform data at the beginning of the load jump as the first characteristic point includes: taking each voltage data point in the first waveform data as a reference, taking preset intervals of equal length forward and backward respectively, wherein the first voltage data point is extended forward by the length of the preset interval, and the extended data is equal to the data of the first voltage data point, and the last voltage data point is extended backward by the length of the preset interval, and the extended data is equal to the data of the last voltage data point; calculating the ratio of the variance of the backward preset interval and the forward preset interval of each voltage data point as discrete data; comparing the discrete data with the preset threshold in turn, and taking the first discrete data greater than the preset threshold as the coordinates of the first characteristic point.

[0042] Specifically, the x coordinate of the first feature point P1 can be obtained by analyzing the current result waveform, such as Figure 6Each voltage data point of L1 in is analyzed. For each data point, an equal length interval M is taken forward and backward (M can be set according to the specific data), and the variance s1 of the forward interval and the variance s2 of the backward interval are taken (the first data needs to be extended forward by M data, and the extended data is the same as the first data; the last data needs to be extended backward by M data, and the extended data is the same as the last data). The value of s2 / s1 is used as the discrete data, and the discrete data fitting curve obtained by each data point is as follows: Figure 8 Search backward from the first discrete data, and when the first value greater than the comparison threshold A (which can be adjusted according to the specific data) is found, it is the x-coordinate of the feature point P1.

[0043]

[0044] in is the sample mean of the forward interval, is the sample mean of the backward interval, and M is the number of samples.

[0045] Step S440, obtaining an output voltage error curve by fitting according to the high value, the low value and the characteristic point.

[0046] In one embodiment, the step of fitting the output voltage error curve according to the high value, the low value and the characteristic point includes: taking the high value as the inflection point of the output voltage error curve, connecting the first characteristic point with the third characteristic point, and taking the low value as the end line to form the output voltage error curve. Calculating the output voltage error curve as Figure 6 Middle L2 is mainly divided into three parts. The first part starts from the high value y1 and ends at the inflection point P1. The second part is connected with the characteristic points P1 and P3. The third part extends horizontally from the characteristic point P3 to the low value y2 and ends.

[0047]

[0048] in L2 is used to characterize the output voltage error waveform caused by the fixture contact resistance.

[0049] Step S450, constructing an output response waveform based on the difference between the first waveform data and the corresponding data point in the output voltage error curve, so as to measure the load according to the output response waveform to obtain a measurement result.

[0050] In one embodiment, based on the difference between the first waveform data and the corresponding data point in the output voltage error curve, the step of constructing the output response waveform includes: subtracting the vertical coordinate of the first waveform data from the vertical coordinate of the output voltage error curve, while keeping the horizontal coordinate unchanged, to obtain the output response waveform.

[0051] In one embodiment, the accurate output response waveform L3 (eg Figure 6 ), L3 is used to characterize the output dynamic response waveform without the influence of fixture contact resistance. L3 is obtained by subtracting the output voltage error curve waveform L2 from the filtered waveform L1 point by point (the ordinates are subtracted, and the abscissa remains unchanged). Based on L3, accurate test results of parameters related to load dynamic response, such as output dynamic response amplitude and response time, can be obtained.

[0052] Based on the technical solution of the above embodiment of the present application, without using a four-wire structure fixture, the test result waveform is filtered, extracted, and analyzed to find out the characteristic points, and the output voltage error curve is calculated and generated. By calculating the filtered data waveform and the error data curve waveform, an accurate output response waveform is obtained, and then the accurate output dynamic response related parameter data is calculated, which can greatly improve the test accuracy and consistency and adapt to a wide range of test products.

[0053] In one embodiment, the present application also provides a system for accurately measuring the dynamic response of a power supply load, comprising: a sampling module, used to obtain waveform raw data for measuring the dynamic response of a power supply load; a filtering module, used to filter the waveform raw data to obtain first waveform data; a waveform analysis module, used to calculate the high value and low value of the first waveform data, wherein the high value and the low value are determined based on the amount of data falling into multiple groups at equal intervals in the first waveform data; a feature calculation module, used to determine corresponding feature points based on the first waveform data and the high value and the low value; an error curve fitting module, used to obtain an output voltage error curve based on the high value, the low value and the feature point; a response measurement module, used to construct an output response waveform based on the difference between the first waveform data and the corresponding data points in the output voltage error curve, so as to measure the load according to the output response waveform and obtain a measurement result.

[0054] The execution process of the system has been described in detail in the aforementioned method embodiment and will not be repeated here.

[0055] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for accurately measuring the dynamic response of a power supply load, characterized in that: include: Obtain the original waveform data of the power supply load dynamic response measurement; Filtering the waveform original data to obtain first waveform data; Calculating a high value and a low value of the first waveform data, wherein the high value and the low value are determined based on the amount of data falling into a plurality of equally spaced groups in the first waveform data; Determine a corresponding feature point according to the first waveform data and the high value and the low value; An output voltage error curve is obtained by fitting according to the high value, the low value and the characteristic point; Based on the difference between the first waveform data and the corresponding data point in the output voltage error curve, an output response waveform is constructed to measure the load according to the output response waveform to obtain a measurement result.

2. The method for accurately measuring the dynamic response of a power supply load according to claim 1, characterized in that: The step of calculating the high value and the low value of the first waveform data comprises: Dividing the first waveform data into a preset number of data groups based on the maximum value and the minimum value of the voltage in the first waveform data as boundaries, and counting the number of the first waveform data falling into each of the data groups; The high value and the low value of the first waveform data are determined according to the intervals where the two data groups with the highest statistical frequencies in each of the data groups are located.

3. The method for accurately measuring the dynamic response of a power supply load according to claim 2, characterized in that: Determining the high value and the low value of the first waveform data according to the interval where the two data groups with the highest statistical frequency in each of the data groups are located includes: The interval boundaries of the two data groups with the highest statistical frequency; The median of the corresponding interval is calculated based on the interval boundary, and the larger median is used as the high value, and the smaller median is used as the low value.

4. The method for accurately measuring the dynamic response of a power supply load according to claim 1, characterized in that: The step of determining corresponding feature points according to the first waveform data and the high value and the low value comprises: Taking the output voltage change inflection point of the first waveform data at the beginning of load jump as the first characteristic point; Taking the abscissa of the first feature point and the ordinate of the low value as the second feature point; On the basis of the second characteristic point, the product of the load transition time and the oscilloscope sampling rate plus the abscissa of the first characteristic point is used as the abscissa of the third characteristic point, and the ordinate of the second characteristic point is used as the ordinate of the third characteristic point.

5. The method for accurately measuring the dynamic response of a power supply load according to claim 4, characterized in that: The step of taking the output voltage change inflection point of the first waveform data at the beginning of load jump as the first characteristic point comprises: Taking each voltage data point in the first waveform data as a reference, taking preset intervals of equal length forward and backward respectively, wherein the first voltage data point is extended forward by the length of the preset interval, and the extended data is equal to the data of the first voltage data point, and the last voltage data point is extended backward by the length of the preset interval, and the extended data is equal to the data of the last voltage data point; Calculate the ratio of the variance of the backward preset interval and the forward preset interval of each voltage data point as discrete data; The discrete data are compared with a preset threshold in sequence, and the first discrete data that is greater than the preset threshold is used as the coordinate of the first feature point.

6. The method for accurately measuring the dynamic response of a power supply load according to claim 5, characterized in that: The step of obtaining an output voltage error curve by fitting the high value, the low value and the characteristic point comprises: The output voltage error curve is formed by taking the high value as the inflection point of the output voltage error curve, connecting the first characteristic point and the third characteristic point, and taking the low value as the end line.

7. The method for accurately measuring the dynamic response of a power supply load according to claim 6, characterized in that: Based on the difference between the first waveform data and the corresponding data point in the output voltage error curve, the step of constructing the output response waveform includes: subtracting the ordinate of the first waveform data from the ordinate of the output voltage error curve, while keeping the abscissa unchanged, to obtain the output response waveform.

8. A system for accurately measuring the dynamic response of a power supply load, characterized in that: include: A sampling module is used to obtain the waveform raw data of the power supply load dynamic response measurement; A filtering module, filtering the original waveform data to obtain first waveform data; A waveform analysis module, configured to calculate a high value and a low value of the first waveform data, wherein the high value and the low value are determined based on the amount of data falling into a plurality of equally spaced groups in the first waveform data; A feature calculation module, used for determining corresponding feature points according to the first waveform data and the high value and the low value; An error curve fitting module, used for fitting an output voltage error curve according to the high value, the low value and the characteristic point; The response measurement module is used to construct an output response waveform based on the difference between the first waveform data and the corresponding data point in the output voltage error curve, so as to measure the load according to the output response waveform to obtain a measurement result.

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