Electric energy quality monitoring method and device based on electric energy meter

Abstract

The invention belongs to the technical field of electric energy quality monitoring, and particularly relates to an electric energy quality monitoring method and device based on an electric energy meter. Obtaining a no-load effective value of the set electrical parameter according to a register value corresponding to the effective value of the set electrical parameter sampled and obtained from the original data of the electric energy meter under the condition that the sampling channel of the set electrical parameter inputs no-load; setting an electrical parameter as voltage or current; under the condition that the value obtained after square processing of the no-load effective value does not exceed a set upper limit threshold value, according to the 32-bit complement of the negative value of the value obtained after square processing of the no-load effective value, the value of the last 16 bits starting from the 14 bits of the complement is obtained; the value is multiplied by the fourteenth power of 2 and then summed with the square of a to-be-corrected set electrical parameter effective value sampled from the original data of the electric energy meter through the sampling channel, and then the square root of the absolute value is used as the corrected set electrical parameter effective value for corresponding calculation or judgment of electric energy quality monitoring.

Description

Technical Field

[0001] The present invention belongs to the technical field of power quality monitoring, and in particular relates to a power quality monitoring method and device based on an electric energy meter. Background Art

[0002] With the development of modern science and technology and new industrial technologies, power quality issues have received increasing attention. Wind power, photovoltaic power generation, arc furnaces, electrified railways, computers, microcontrollers and other power system power sources and loads will have an adverse effect on the power quality of the power system, thus posing challenges to the safe production and operation of the power system, especially with the interconnection of power grid areas. In February 2022, State Grid Corporation of China issued the "Opinions of State Grid Corporation of China on Promoting the Construction of a New Power Load Management System", requiring the adherence to "demand response priority, orderly power consumption guarantee, and power conservation assistance", to create a company-level new power load management system, and achieve precise load control and normalized demand-side management under orderly power consumption. Against the background of the construction of new power systems and whole-county photovoltaics, the demand for DC source-load access such as electric vehicles and distributed energy is developing rapidly, the load and terminal power supply of the distribution network are rising sharply, and the power quality of the distribution network has changed significantly. Monitoring of power quality is imminent.

[0003] The way to measure power quality is usually to analyze a variety of power quality data that describe power quality from different angles, and evaluate the power quality based on the analysis results. Due to the variety of measurement angles, the power quality data is also varied.

[0004] However, power quality data is obtained by analyzing, calculating or judging the parameter values ​​directly obtained from the power meter. When the power quality monitoring system captures, analyzes and records various power quality data in the power grid (such as voltage fluctuations, harmonics, frequency deviation, voltage imbalance, etc.), the accuracy of the parameter values ​​directly obtained from the power meter is often not high enough, making it difficult to achieve high-precision standards. This lack of accuracy directly leads to a large deviation between the monitoring data and the actual power quality status, and cannot truly reflect the subtle changes and potential problems in the power quality of the power grid, thereby misleading the power operation and maintenance personnel in their judgment of the power grid operation status, making it impossible for them to discover and deal with potential power quality problems in a timely manner, threatening the safe and stable operation of the power grid. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for monitoring power quality based on an electric energy meter, so as to solve the problem in the prior art that the accuracy of the parameter values ​​directly obtained from the electric energy meter is not high enough, resulting in a deviation between the monitoring data and the actual power quality status, thereby affecting the results of the power quality analysis and causing large errors in the power quality assessment of the power grid.

[0006] In order to achieve the above-mentioned object, the present invention provides a method for monitoring power quality based on an electric energy meter, wherein the no-load effective value of the set electric parameter is obtained by sampling the register value corresponding to the effective value of the set electric parameter obtained from the original data of the electric energy meter when the sampling channel of the set electric parameter is inputted without load; the set electric parameter is voltage or current;

[0007] When the value after the no-load effective value is squared does not exceed the set upper limit threshold, the 32-bit complement of the negative value of the no-load effective value is used to obtain the value of the last 16 bits starting from the 14th bit of the complement. This value is multiplied by 2 to the 14th power and then summed with the square of the effective value of the set electrical parameter to be corrected, which is sampled from the original data of the electric energy meter through the sampling channel. The square root of the absolute value of the sum is used as the corrected effective value of the set electrical parameter, which is used for calculation or judgment of power quality monitoring.

[0008] Beneficial effect: The present invention corrects the register value corresponding to the effective value of the set electrical parameter sampled from the original data of the electric energy meter when the sampling channel input of the set electrical parameter is no-loaded, thereby obtaining the corrected effective value of the electrical parameter, and using the corrected effective value of the electrical parameter as the basis for measuring the quality of electric energy. The sampling channel input is no-loaded to obtain the background noise (i.e., the no-load effective value) of the set electrical parameter of the electric energy meter, and then the electrical parameter containing the background noise is corrected by setting an algorithm to obtain the corrected effective value of the electrical parameter; compared with the effective value of the electrical parameter sampled from the original data, the corrected effective value of the electrical parameter effectively avoids the influence of the background noise on the quality of electric energy and improves the accuracy of the effective value of the electrical parameter. It is more accurate and reliable to use the corrected effective value of the electrical parameter as the basis for measuring the quality of electric energy, thereby making the evaluation of the power quality of the power grid more accurate and reliable, so as to perform correct and timely power quality maintenance and management of the power grid.

[0009] Furthermore, the product of the channel gain normalization value and the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, and the sum of the product of the DC offset register value and 2 to the 12th power is used as the value of the set DC quantity after correction, which is used for corresponding calculation or judgment of power quality monitoring.

[0010] Furthermore, the product of the register value of the full-wave voltage amplitude obtained by the register value of the full-wave voltage effective value corresponding to the corrected rated voltage and the ratio of the overvoltage voltage in the phase where the rated voltage is located to the rated voltage is rounded off as the corrected overvoltage monitoring threshold, which is used for corresponding calculations or judgments of power quality monitoring.

[0011] Furthermore, according to the register value corresponding to the effective value of the set electrical parameter sampled from the original data of the electric energy meter when the sampling channel input of the set electrical parameter is no-load, the method for obtaining the no-load effective value of the set electrical parameter includes: continuously obtaining the register value corresponding to the effective value of the set electrical parameter at least twice within a certain period of time, and averaging each of the continuously obtained register values; and using the average value as the no-load effective value of the set electrical parameter.

[0012] The present invention also provides an electric energy quality monitoring device based on an electric energy meter, the device comprising a foreground processing module; the foreground processing module obtains the no-load effective value of the set electric parameter according to the register value corresponding to the set electric parameter effective value obtained by sampling from the original data of the electric energy meter when the sampling channel of the set electric parameter is inputted without load; the set electric parameter is voltage or current;

[0013] When the value after the no-load effective value is squared does not exceed the set upper limit threshold, the 32-bit complement of the negative value of the no-load effective value is used to obtain the value of the last 16 bits starting from the 14th bit of the complement. This value is multiplied by 2 to the 14th power and then summed with the square of the effective value of the set electrical parameter to be corrected, which is sampled from the original data of the electric energy meter through the sampling channel. The square root of the absolute value of the sum is used as the corrected effective value of the set electrical parameter, which is used for calculation or judgment of power quality monitoring.

[0014] Furthermore, the foreground processing module is also used to use the product of the channel gain normalization value and the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, and the sum of the product of the DC offset register value and 2 to the 12th power as the value of the set DC quantity after correction, for corresponding calculation or judgment of power quality monitoring.

[0015] Furthermore, the foreground processing module is also used to round the product of the register value of the full-wave voltage amplitude obtained by the register value of the full-wave voltage effective value corresponding to the corrected rated voltage and the ratio of the overvoltage voltage in the phase where the rated voltage is located to the rated voltage as the corrected overvoltage monitoring threshold, which is used for corresponding calculations or judgments of power quality monitoring.

[0016] Furthermore, the foreground processing module is also used to obtain the register value corresponding to the effective value of the set electrical parameter by sampling from the original data of the electric energy meter when the sampling channel input of the set electrical parameter is no-load. The method for obtaining the no-load effective value of the set electrical parameter includes: continuously obtaining the register value corresponding to the effective value of the set electrical parameter at least twice within a certain period of time, and averaging each continuously obtained register value; and using the average value as the no-load effective value of the set electrical parameter.

[0017] Furthermore, it also includes a security authentication module and a serial communication module; the security authentication module is used to perform security authentication on the electric energy meter through a key; the serial communication module is used to establish a communication connection with the electric energy meter after the security authentication is passed to obtain the original data of the electric energy meter;

[0018] It also includes a background processing module; the background processing module is used to obtain a time-consistent state by timing, so as to control the sampling channels of the foreground processing module, including the sampling channels for setting the electrical parameters and the sampling channels for setting the DC quantity, to sample the same electrical parameter and DC quantity at the same sampling time;

[0019] It also includes a statistical analysis module; the statistical analysis module is used to update statistics of the set item data in the data obtained during the power quality monitoring process according to at least one set period corresponding to the set period;

[0020] It also includes an event processing module; the event processing module is used to judge the corrected set electric parameter effective value according to the set abnormal judgment condition, and obtain the corresponding judgment result to determine whether the power quality data is abnormal; according to the time when the abnormal power quality data is generated and ended as the time when the abnormal event occurs and ends, the abnormal power quality data is recorded as an abnormal event; the abnormal event is reported and processed according to the set reporting method; the set reporting method includes:

[0021] 1) Actively report or follow up report when abnormal events occur;

[0022] 2) Actively report or follow-up report the time when the abnormal event ends;

[0023] 3) The occurrence and end time of abnormal events are actively reported or reported later;

[0024] The active reporting is automatic reporting when an abnormal event occurs, and the follow-up reporting is reporting along with other data when the electric energy meter copies the data;

[0025] It also includes a freezing module; the freezing module is used to freeze the set item data in the data obtained during the power quality monitoring process according to at least one set period for the corresponding set period of data.

[0026] Beneficial effects: The power quality monitoring device based on the power meter can achieve the same beneficial effects as the above-mentioned power quality monitoring method based on the power meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a correction flow chart of correcting the effective value of a set electric parameter in an embodiment of the electric energy quality monitoring method based on an electric energy meter of the present invention;

[0028] Figure 2 It is a schematic diagram of modules of a power quality monitoring device based on a power meter in an embodiment of the power quality monitoring device based on a power meter of the present invention;

[0029] Figure 3 This is an application example diagram of parameter configuration in an embodiment of a power quality monitoring device based on an electric energy meter of the present invention;

[0030] Figure 4 This is an example diagram of reporting information of a voltage sag abnormal event in an embodiment of a power quality monitoring device based on an electric energy meter of the present invention;

[0031] Figure 5 This is an application example diagram of reporting abnormal events in a configuration interface of reporting processing in an embodiment of a power quality monitoring device based on an electric energy meter of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0033] Embodiment of the power quality monitoring method based on the power meter

[0034] This embodiment provides a method for monitoring power quality based on an electric energy meter. Figure 1 As shown, the method obtains the no-load effective value of the set electrical parameter by sampling the register value corresponding to the effective value of the set electrical parameter obtained from the original data of the electric energy meter when the sampling channel of the set electrical parameter is input without load; the manner of obtaining the no-load effective value of the set electrical parameter includes: continuously obtaining the register value corresponding to the effective value of the set electrical parameter at least twice within a certain period of time, and averaging each of the continuously obtained register values; using the average value as the no-load effective value of the set electrical parameter; the set electrical parameter is voltage or current;

[0035] When the value after the no-load effective value is squared does not exceed the set upper limit threshold, the 32-bit complement of the negative value of the no-load effective value is used to obtain the value of the last 16 bits starting from the 14th bit of the complement. This value is multiplied by 2 to the 14th power and then summed with the square of the effective value of the set electrical parameter to be corrected, which is sampled from the original data of the electric energy meter through the sampling channel. The square root of the absolute value of the sum is used as the corrected effective value of the set electrical parameter, which is used for calculation or judgment of power quality monitoring.

[0036] Specifically, taking the +A phase current effective value as an example, the calculation process of the register value IA_OS corresponding to the A phase current effective value is as follows:

[0037] 1) Configure the standard source (the standard source is a device used to calibrate and verify various measuring devices or systems, which can generate specific voltage and current signals, and can independently adjust the amplitude and phase difference of these signals), so that U = Un (U is the standard value of the voltage register, satisfying the formula U = int[(Uv / 0.8)*2^27] (Uv is the voltage signal sampled at the rated voltage, including the value of ADC gain, unit V); Un is the rated voltage), and the current sampling channel input is unloaded;

[0038] 2) Read the current effective value register value (i.e., the register value corresponding to the set electrical parameter effective value obtained by sampling from the original data of the electric energy meter) through the MCU, read 10 current effective value register values ​​continuously (read once every 250ms), and calculate the average value I of the 10 current effective value register values Aave , with the average value I Aave As the no-load effective value of phase A current.

[0039] 3) Ask for I Aave The square of I Aave 2 ; In general, this value will not exceed the set upper threshold of 2^29-1. If it exceeds 2^29-1 after squaring, it will exceed the range that the offset register can correct, and will not be able to achieve the purpose of offset correction. Instead, the value will increase with correction.

[0040] 4) Take the above I Aave 2 The negative complement of the bit14~bit29 is used as the value of the negative complement of the bit14~bit29 as IA_OS (that is, the register value corresponding to the effective value of the A phase current), and the IA_OS is filled into the register corresponding to the effective value of the A phase current.

[0041] 5) The offset correction ending formula of the register value Ix_OS corresponding to the effective value of the x-phase current is as follows:

[0042] Ix_OS=-Ix_ Avreg 2 / 2 14

[0043] Where Ix_ Avreg is the average value of a current register (x refers to one of the three phases A, B, and C, so Ix can be IA / IB / IC). Avreg Refers to the average value of the two or more x-phase current effective value registers read. In other embodiments, Ix_ Avreg It can also be replaced by reading the x-phase current effective value register value only once.

[0044] Taking the case where the A phase current input is zero as an example, in this case, the register value corresponding to the A phase current effective value is 0x0000483 (it can be read once or twice or more to take the average value), and the decimal number corresponding to the register value is 1155; 1155 is squared and its inverse code is obtained to obtain 1155*1155=1334025=0x145B09; its 32-bit complement code is 0Xffeba4f7; take the negative bit 29 to bit 14 of the complement code (that is, 0Xffeba4f6 divided by 2^14) to obtain 0xFFAE (that is, IA_OS), and fill the IA_OS into the current effective value offset correction register corresponding to the A phase current effective value IA_OS.

[0045] The effective value offset correction register is used to correct the small signal accuracy of the voltage or current effective value. Take the effective value of the current sampled from the original data of the electric energy meter by channel A (that is, the register value corresponding to the effective value of the current of phase A before correction) as an example, assuming that the above register value is IA; the effective value of the current of phase A after correction is IA'; the standard effective value of the register value corresponding to the effective value of the current of phase A is IA_OS; then the correction formula of the effective value offset correction is as follows:

[0046]

[0047] In this embodiment, the product of the channel gain normalization value and the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, and the sum of the product of the DC offset register value and 2 to the 12th power is used as the value of the set DC quantity after correction, which is used for corresponding calculation or judgment of power quality monitoring.

[0048] Specifically, channel DC offset correction is used to replace high-pass filtering to eliminate offset errors when testing DC quantities. The DC component represented by the DC offset register is equivalent to directly superimposing the DC component on the sampled waveform. Taking the IA channel as an example, the correction formula for DC offset correction is as follows:

[0049] IA'=IA×(1+GSIA)+DOCS_IA×2 12

[0050] Among them: IA is the actual input DC value of channel A (that is, the value of the set DC value sampled and obtained from the original data of the electric energy meter to be calibrated); IA' is the value of the DC value actually read out of channel IA after calibration (that is, the value of the set DC value after calibration); GSIA is the channel gain normalization value; DCOS_IA is the DC offset register value.

[0051] In this embodiment, the product of the register value of the full-wave voltage amplitude obtained by the register value of the full-wave voltage effective value corresponding to the corrected rated voltage and the ratio of the overvoltage voltage in the phase where the rated voltage is located to the rated voltage is rounded off as the corrected overvoltage monitoring threshold value, which is used for corresponding calculation or judgment of power quality monitoring.

[0052] Specifically, the overvoltage monitoring threshold refers to a voltage upper limit value set in the power system, electronic equipment or other related fields. When the monitored voltage exceeds this threshold, the system will trigger the corresponding overvoltage protection measures to prevent damage to the device and ensure system safety. According to the rated voltage of a phase, an overvoltage monitoring threshold that is higher than the rated voltage but not exceeding the maximum withstand voltage of the phase can be directly set; the calculation formula for correcting the overvoltage monitoring threshold (OVLVL) is:

[0053]

[0054] REGVn is the full-wave voltage effective value register value of the corrected rated voltage input, and K is the ratio of the overvoltage of a certain phase to the corrected rated voltage. If the overvoltage is 1.2 times the rated voltage, then K = 1.2.

[0055] Embodiment of power quality monitoring device based on electric energy meter

[0056] This embodiment provides a power quality monitoring device based on an electric energy meter, which includes a foreground processing module; the foreground processing module obtains the no-load effective value of the set electric parameter according to the register value corresponding to the effective value of the set electric parameter obtained by sampling from the original data of the electric energy meter when the sampling channel input of the set electric parameter is no-load; the method of obtaining the no-load effective value of the set electric parameter includes: obtaining the register value corresponding to the effective value of the set electric parameter multiple times at consecutive set time intervals, and averaging the register value; setting the electric parameter to voltage or current;

[0057] When the value after the no-load effective value is squared does not exceed the set upper limit threshold, the 32-bit complement of the negative value of the value after the no-load effective value is squared to obtain the value of the last 16 bits starting from the 14th bit of the complement, and the value is multiplied by 2 to the 14th power and then summed with the square of the effective value of the set electrical parameter to be corrected sampled from the original data of the electric energy meter through the sampling channel, and the square root of the absolute value of the sum is used as the corrected effective value of the set electrical parameter for calculation or judgment of power quality monitoring. Specifically, in terms of the logical relationship between each function, the device can include one or more of a security authentication module, a serial communication module, a background processing module, an upgrade processing module (only for software upgrades), a foreground processing module, an output module (only for realizing the function of responding to the arrival signal through an indicator light), an event processing module, a statistical analysis module, and a freeze processing module. The logical operation relationship of each module is as follows: Figure 2 In terms of power quality monitoring, the foreground processing module obtains the register value corresponding to the effective value of the set electrical parameter by sampling from the original data of the electric energy meter through SPI (the voltage in the set electrical parameter includes the fundamental voltage, which is used as the reference voltage for harmonic analysis; the current in the set electrical parameter includes the fundamental current, which is used as the reference current for harmonic analysis), and corrects the sampled register value to eliminate the background noise and process it into more accurate and reliable power quality monitoring data for use by the statistical analysis module, the freezing module, and the event module.

[0058] In this embodiment, the sampling waveform data obtained when the foreground processing module samples is the sampling waveform data obtained by using 7 channels to start ADC sampling of the electric energy meter under the condition of clock consistency, and the sampling frequency is 8KHz. The full differential input is adopted, and the maximum differential signal input amplitude is 830mV at the peak value. The register value (including fundamental wave and half-wave data) corresponding to the set electrical parameter effective value sampled and obtained from the original data collected by the 7 sampling channels is corrected by the effective value offset to obtain the corrected set electrical parameter effective value that eliminates the background noise interference (this value is compared with the set electrical parameter effective value sampled and obtained in the original data, because the background noise interference is eliminated, the reflection of the actual power quality is more real); the above-mentioned corrected electrical parameter effective value is obtained after FFT operation to obtain the processed electrical parameter effective value (the processed electrical parameter effective value can almost truly reflect the actual power quality) (except harmonics) for use by other modules.

[0059] The correction formula for effective value offset correction in this embodiment is the same as the correction formula for effective value offset correction in the embodiment of the power quality monitoring method based on the power meter.

[0060] In this embodiment, the foreground processing module is also used to use the product of the channel gain normalization value and the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, and the sum of the product of the DC offset register value and 2 to the power of 12 as the value of the set DC quantity after correction, for corresponding calculation or judgment of power quality monitoring.

[0061] Specifically, the value of the set DC quantity sampled and obtained from the original data collected by the above-mentioned 7 sampling channels (including fundamental wave and half-wave data) is corrected by DC offset to obtain the value of the corrected set DC quantity with the background noise eliminated (compared with the value of the set DC quantity sampled and obtained from the original data, this value reflects the actual power quality more realistically because the background noise is eliminated); the value of the above-mentioned corrected set DC quantity is subjected to FFT operation to obtain the value of the processed set DC quantity (the value of the processed set DC quantity can almost truly reflect the actual power quality) (except harmonics) for use by other modules.

[0062] The correction formula for DC offset correction in this embodiment is the same as the correction formula for DC offset correction in the embodiment of the power quality monitoring method based on the power meter.

[0063] In this embodiment, the foreground processing module is also used to round the product of the register value of the full-wave voltage amplitude obtained by the register value of the full-wave voltage effective value corresponding to the corrected rated voltage and the ratio of the overvoltage voltage in the phase where the rated voltage is located to the rated voltage as the corrected overvoltage monitoring threshold, which is used for corresponding calculations or judgments for power quality monitoring.

[0064] Specifically, the overvoltage monitoring threshold sampled and obtained from the original data collected by the above 7 sampling channels is corrected by the overvoltage monitoring threshold to obtain a corrected overvoltage monitoring threshold, which is more accurate and reliable than the uncorrected overvoltage monitoring threshold.

[0065] The correction formula for correcting the overvoltage monitoring threshold value (OVLVL) in this embodiment is the same as the correction formula for correcting the overvoltage monitoring threshold value (OVLVL) in the embodiment of the power quality monitoring method based on the power meter.

[0066] In this embodiment, the power quality monitoring device also includes a security authentication module and a serial communication module; the security authentication module is used to perform security authentication on the power meter through a key; the serial communication module is used to establish a communication connection with the power meter after the security authentication is passed to obtain the original data of the power meter.

[0067] Specifically, the smart electricity meter is securely authenticated by means of key authentication; after the security authentication with the smart meter is passed, the metering parameters are synchronized, the power quality data of the smart electricity meter is received, and communication tests, serial port sending and receiving, baud rate changes, clock synchronization, active reporting, module reconnection and other operations are performed.

[0068] In this embodiment, the power quality monitoring device also includes a background processing module, which is used to obtain a time-consistent state through timing; specifically, the background processing module is used to obtain a time-consistent state through timing to control the sampling channels of the foreground processing module, including the sampling channels for setting electrical parameters and the sampling channels for setting DC quantities, to sample the same electrical parameter / DC quantity at consistent sampling times.

[0069] Specifically, the time consistency is achieved by counting according to the system beat, obtaining the year, month, day, hour, minute, and second time stamps to provide time and keep it consistent. In addition, a self-check is performed every minute, and the fault condition is displayed accordingly. Taking the use of the module to illustrate the fault condition as an example, if the module status word 1 is 1, it means that the total harmonic distortion rate of the three-phase current exceeds the limit, thereby ensuring the reliability of operation.

[0070] In this embodiment, the power quality monitoring device further includes a statistical analysis module; the statistical analysis module is used to perform update statistics of the set item data in the data obtained during the power quality monitoring process according to at least one set period.

[0071] Specifically, multiple execution cycles (i.e., set time intervals) are set. In the present embodiment, there are four execution cycles of 3 seconds, 10 seconds, 10 minutes, and 2 hours; to meet the needs of statistics and updates on daily extreme values, mean values, probability values, monthly intervals, voltage qualification rates and other data.

[0072] In this embodiment, the power quality monitoring device also includes an event processing module; the event processing module is used to judge the corrected set electric parameter effective value according to the set abnormal judgment condition, and obtain the corresponding judgment result to determine whether the power quality data is abnormal; according to the time when the abnormal power quality data is generated and ended as the time when the abnormal event occurs and ends, the abnormal power quality data is recorded as an abnormal event; the abnormal event is reported and processed according to the set reporting method; the set reporting method includes:

[0073] 1) Actively report or follow up report when abnormal events occur;

[0074] 2) Actively report or follow-up report the time when the abnormal event ends;

[0075] 3) The occurrence and end time of abnormal events are actively reported or reported later;

[0076] The active reporting is automatic reporting when an abnormal event occurs, and the follow-up reporting is reporting along with other data when the electric energy meter copies data.

[0077] Specifically, Figure 3 , 4 As shown in Figure 5, a simulated voltage sag abnormal event is taken as an example. In this abnormal event, the abnormal judgment condition is that the actual voltage continues to be lower than the actual voltage reference value 210V (the actual value of the voltage value) added at the beginning within the set judgment time (i.e., within 10 seconds from 10:17:40 to 10:17:50). Figure 4 The reading content shown in the figure is: Phase A voltage (20000201) 0210.0153V) and Figure 3 The voltage sag threshold (percentage) shown is 90.00% (i.e. Figure 3 The voltage sag threshold value shown is 90.00 (unit: %)) and the voltage sag threshold value is 189V (i.e., the threshold reference value is set to 210*90%=189V. The actual value of the voltage sag threshold value is Figure 3 The reading content shown in is: Phase A voltage (20000201) 0188.3874V); if the abnormal judgment condition is met, the judgment result is that the power quality data (i.e. the corrected voltage effective value) is abnormal, and the abnormal power quality data is recorded and saved as the content of the abnormal event (such as Figure 4 As shown, in this embodiment, the abnormal judgment condition is met, so the abnormal power quality data has been recorded and saved as the content of the abnormal event), and then restored to the previous actual voltage reference value 210V (that is, the actual voltage after recovery, the real value of the voltage value is Figure 4 The reading content shown in is: Phase A voltage (20000201) 0210.0033V) and the abnormal event is reported according to the set reporting method (such as Figure 5 As shown, to report abnormal events, select the abnormal events you want to report and check the corresponding "Set Reporting Flag"; Figure 5 5 abnormal events are selected in the report.

[0078] The above reporting methods are divided into the following three types:

[0079] 1) Report when an abnormal event occurs, that is, report when abnormal power quality data is generated (i.e. Figure 5 In the "Set Reporting Method" corresponding to the abnormal event shown, check "Report when it occurs";

[0080] 2) Report when abnormal events end; that is, report when abnormal power quality data ends (i.e. Figure 5 In the "Set Reporting Method" corresponding to the abnormal event shown, check "End Reporting");

[0081] 3) Abnormal events are reported both when they occur and when they end; that is, abnormal power quality data is reported both when they occur and when they end (i.e. Figure 5 In the "Set Reporting Method" corresponding to the abnormal event shown, check "Occur Reporting" and "End Reporting").

[0082] In addition, when reporting abnormal events, it is divided into active reporting (that is, according to user needs, by sending 698 data frames, you can configure whether the event is actively reported, what data is required for active reporting, etc.) and follow-up reporting; Figure 5 As shown in the figure, active reporting means reporting automatically when an abnormal event occurs; follow-up reporting means reporting along with other data when the electric energy meter copies the data (such as Figure 5 As shown in the figure, the five events with "Active, follow-up reporting operation" checked as "Follow-up reporting" are the events to be followed and reported).

[0083] In this embodiment, the power quality monitoring device further includes a freezing module; the freezing module is used to freeze the set item data in the data acquired during the power quality monitoring process according to at least one set period for the corresponding set period.

[0084] Specifically, multiple freezing cycles (i.e., set time intervals) are set to freeze data related to metering and power quality. The freezing cycles are divided into minute freezing, daily freezing, and monthly freezing. The data that has been frozen is recorded and stored. The data cannot be changed or deleted.

[0085] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, but do not constitute a limitation to the present invention.

Claims

1. A method for monitoring power quality based on an electric energy meter, characterized in that: According to the register value corresponding to the effective value of the set electrical parameter obtained by sampling from the original data of the electric energy meter when the sampling channel of the set electrical parameter is inputted without load, the no-load effective value of the set electrical parameter is obtained; Set the electrical parameter to voltage or current; When the value after the no-load effective value is squared does not exceed the set upper limit threshold, the 32-bit complement of the negative value of the no-load effective value is used to obtain the value of the last 16 bits starting from the 14th bit of the complement. This value is multiplied by 2 to the 14th power and then summed with the square of the effective value of the set electrical parameter to be corrected, which is sampled from the original data of the electric energy meter through the sampling channel. The square root of the absolute value of the sum is used as the corrected effective value of the set electrical parameter, which is used for calculation or judgment of power quality monitoring.

2. The method for monitoring power quality based on electric energy meter according to claim 1, characterized in that: The product of the channel gain normalization value and the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, and the sum of the product of the DC offset register value and 2 to the 12th power is used as the value of the set DC quantity after correction, which is used for corresponding calculation or judgment of power quality monitoring.

3. The method for monitoring power quality based on an electric energy meter according to claim 1 or 2, characterized in that: The product of the register value of the full-wave voltage amplitude obtained by the register value of the full-wave voltage effective value corresponding to the corrected rated voltage and the ratio of the overvoltage voltage in the phase where the rated voltage is located to the rated voltage is rounded off as the corrected overvoltage monitoring threshold, which is used for corresponding calculation or judgment of power quality monitoring.

4. The method for monitoring power quality based on an electric energy meter according to claim 1 or 2, characterized in that: According to the register value corresponding to the effective value of the set electrical parameter sampled from the original data of the electric energy meter when the sampling channel input of the set electrical parameter is no-load, the method for obtaining the no-load effective value of the set electrical parameter includes: continuously obtaining the register value corresponding to the effective value of the set electrical parameter at least twice within a certain period of time, and averaging each of the continuously obtained register values; and using the average value as the no-load effective value of the set electrical parameter.

5. A power quality monitoring device based on an electric energy meter, characterized in that: Including foreground processing module; The foreground processing module obtains the no-load effective value of the set electrical parameter by sampling the register value corresponding to the effective value of the set electrical parameter obtained from the original data of the electric energy meter according to the sampling channel input of the set electrical parameter when the sampling channel input is no-load; Set the electrical parameter to voltage or current; When the value after the no-load effective value is squared does not exceed the set upper limit threshold, the 32-bit complement of the negative value of the no-load effective value is used to obtain the value of the last 16 bits starting from the 14th bit of the complement. This value is multiplied by 2 to the 14th power and then summed with the square of the effective value of the set electrical parameter to be corrected, which is sampled from the original data of the electric energy meter through the sampling channel. The square root of the absolute value of the sum is used as the corrected effective value of the set electrical parameter, which is used for calculation or judgment of power quality monitoring.

6. The power quality monitoring device based on the power meter according to claim 5 is characterized in that: The foreground processing module is also used to use the product of the channel gain normalization value and the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, the value of the set DC quantity sampled and obtained from the original data of the electric energy meter to be corrected, and the sum of the product of the DC offset register value and 2 to the 12th power as the value of the set DC quantity after correction, for corresponding calculation or judgment of power quality monitoring.

7. The power quality monitoring device based on the power meter according to claim 5 or 6, characterized in that: The foreground processing module is also used to round the product of the register value of the full-wave voltage amplitude obtained by the register value of the full-wave voltage effective value corresponding to the corrected rated voltage and the ratio of the overvoltage voltage in the phase where the rated voltage is located to the rated voltage as the corrected overvoltage monitoring threshold, which is used for corresponding calculation or judgment of power quality monitoring.

8. The power quality monitoring device based on the power meter according to claim 5 or 6, characterized in that: The foreground processing module is also used to obtain a register value corresponding to the effective value of the set electrical parameter by sampling from the original data of the electric energy meter when the sampling channel input of the set electrical parameter is no-load. The method for obtaining the no-load effective value of the set electrical parameter includes: continuously obtaining the register value corresponding to the effective value of the set electrical parameter at least twice within a certain period of time, and averaging each of the continuously obtained register values; and using the average value as the no-load effective value of the set electrical parameter.

9. The power quality monitoring device based on the power meter according to claim 5 or 6, characterized in that: It also includes a security authentication module and a serial communication module; the security authentication module is used to perform security authentication on the electric energy meter through a key; the serial communication module is used to establish a communication connection with the electric energy meter after the security authentication is passed to obtain the original data of the electric energy meter; Also includes background processing modules; The background processing module is used to obtain a time-consistent state by timing, so as to control the sampling channels of the foreground processing module, including the sampling channels for setting the electrical parameters and the sampling channels for setting the DC quantity, to sample the same electrical parameter and DC quantity at the same sampling time; It also includes a statistical analysis module; the statistical analysis module is used to update statistics of the set item data in the data obtained during the power quality monitoring process according to at least one set period corresponding to the set period; It also includes an event processing module; the event processing module is used to judge the corrected set electrical parameter effective value according to the set abnormal judgment condition, and obtain the corresponding judgment result to determine whether the power quality data is abnormal; Determine the time when the abnormal event occurs and ends based on the time when the abnormal power quality data is generated and ended, and record the abnormal power quality data as an abnormal event; Report the abnormal event according to the set reporting method; The reporting method of the settings includes: 1) Actively report or follow up report when abnormal events occur; 2) Actively report or follow-up report the time when the abnormal event ends; 3) The occurrence and end time of abnormal events are actively reported or reported later; The active reporting is automatic reporting when an abnormal event occurs, and the follow-up reporting is reporting along with other data when the electric energy meter copies the data; It also includes a freezing module; the freezing module is used to freeze the set item data in the data obtained during the power quality monitoring process according to at least one set period for the corresponding set period of data.

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