Relay branch state detection method, device, medium and electric meter of three-phase electric meter
By acquiring the superimposed digital voltage signals of each phase branch of a three-phase meter relay, extracting the voltage peak value and its timestamp, and combining them with the state determination conditions, the problem of the single state identification function in the existing technology is solved, and accurate judgment and fault diagnosis of the state of the three-phase meter relay branch are realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN STAR INSTR
- Filing Date
- 2025-10-22
- Publication Date
- 2026-07-07
Smart Images
Figure CN121164892B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of smart meters, and more particularly to a method, device, medium, and meter for detecting the status of a relay branch in a three-phase meter. Background Technology
[0002] In the field of power metering and grid management, three-phase smart meters, as core equipment, play a crucial role. The stable and reliable operation of their internal relays directly affects the power supply safety of users and the stable operation of the power grid.
[0003] The common solution for detecting the three-phase electrical status at the back end of a relay is to use three independent resistors and diodes to form a voltage divider and rectifier circuit to process the voltage signals of each phase. Then, the signals are converted by transistors and their peripheral circuits, and finally, high and low level signals are output to the single general purpose input / output (GPIO) port of the microcontroller unit (MCU) to determine the tripping or closing status of the relay.
[0004] However, the aforementioned existing solutions have significant technical drawbacks. Because these solutions ultimately output only a single comprehensive status signal, the system can only determine the overall on / off status of the three-phase power supply, resulting in a relatively limited status identification function. Summary of the Invention
[0005] This invention provides a method, device, medium, and meter for detecting the status of a relay branch of a three-phase electricity meter, in order to solve the problem that the existing technology can only determine the overall on / off status of three-phase power supply, resulting in a relatively simple status identification function.
[0006] A method for detecting the status of a relay branch in a three-phase electricity meter, comprising:
[0007] Obtain the superimposed digital voltage signal of each phase branch of the three-phase meter relay;
[0008] Based on the superimposed digital voltage signal, the peak voltage of each phase branch and the timestamp corresponding to the peak voltage are obtained;
[0009] Based on the voltage peak value, the timestamp, and the preset state determination conditions, the state result of the three-phase meter relay branch is obtained.
[0010] A relay branch status detection device for a three-phase electricity meter, comprising:
[0011] The voltage acquisition module is used to acquire the superimposed digital voltage signal of each phase branch of the three-phase meter relay;
[0012] The peak extraction module is used to obtain the voltage peak value of each phase branch and the timestamp corresponding to the voltage peak value based on the superimposed voltage digital signal.
[0013] The status result output module is used to obtain the status result of the three-phase meter relay branch based on the voltage peak value, the timestamp, and the preset status judgment conditions.
[0014] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for detecting the status of the relay branch of a three-phase meter.
[0015] An electricity meter, wherein the electricity meter is used in the relay branch status detection method of the above-mentioned three-phase electricity meter.
[0016] This invention provides a method, apparatus, medium, and meter for detecting the status of relay branches in a three-phase electricity meter. The method includes acquiring the superimposed digital voltage signal of each phase branch of the three-phase electricity meter relay; extracting the voltage peak value and its corresponding timestamp of each phase branch based on the superimposed digital voltage signal; and determining and outputting the status result of each branch of the three-phase electricity meter relay by combining the voltage peak value, timestamp, and preset status judgment conditions. Compared to existing technologies that only output a single comprehensive status signal, resulting in the system only being able to grasp the overall on / off status of the three-phase power supply and unable to achieve individual identification and monitoring of the voltage status of each phase, this invention, by accurately extracting the peak value of each phase voltage and its corresponding timestamp for discrimination and analysis, not only achieves effective verification of the relay's back-end opening and closing status but also supports the diagnosis of phase loss faults and the identification of phase sequence errors in the three-phase power supply. The detection dimension is improved from the traditional overall judgment to precise single-phase positioning, significantly enhancing the granularity and accuracy of status monitoring. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a flowchart of a method for detecting the status of a relay branch of a three-phase meter according to an embodiment of the present invention;
[0019] Figure 2 This is a circuit diagram of the tripping and closing detection method for the relay branch status detection method of a three-phase meter in one embodiment of the present invention;
[0020] Figure 3 This is a waveform diagram of the phase voltage of the three-phase 220VAC line voltage in a relay branch status detection method for a three-phase meter according to an embodiment of the present invention.
[0021] Figure 4This is a waveform diagram of the composite voltage after the three-phase 220VAC line voltage is superimposed by voltage divider rectification in a method for detecting the status of the relay branch of a three-phase meter according to an embodiment of the present invention.
[0022] Figure 5 This is a waveform diagram of the composite voltage after the three-phase 90VAC line voltage is superimposed by voltage divider rectification in a method for detecting the status of the relay branch of a three-phase meter according to an embodiment of the present invention.
[0023] Figure 6 This is a waveform diagram of the composite voltage after the three-phase 220VAC line voltage is superimposed by voltage divider rectification in a method for detecting the status of the relay branch of a three-phase meter according to an embodiment of the present invention.
[0024] Figure 7 This is a waveform diagram of the composite voltage after the three-phase 280VAC line voltage is superimposed by voltage divider rectification in a method for detecting the status of the relay branch of a three-phase meter according to an embodiment of the present invention.
[0025] Figure 8 This is a normal phase voltage waveform diagram of the three-phase 220VAC line voltage after voltage division, rectification and superposition in a method for detecting the status of the relay branch of a three-phase meter according to an embodiment of the present invention.
[0026] Figure 9 This is a waveform diagram of the voltage of phase A after the three-phase 220VAC line voltage is superimposed by voltage divider rectification in a relay branch state detection method of a three-phase meter according to an embodiment of the present invention.
[0027] Figure 10 This is a waveform diagram of the voltage of phase B after the three-phase 220VAC line voltage is superimposed by voltage divider rectification in a method for detecting the status of the relay branch of a three-phase meter in an embodiment of the present invention.
[0028] Figure 11 This is a waveform diagram of the voltage of phase C after the three-phase 220VAC line voltage is superimposed by voltage divider rectification in a relay branch state detection method of a three-phase meter according to an embodiment of the present invention.
[0029] Figure 12 This is a voltage waveform diagram of the normal phase sequence after the three-phase 220VAC line voltage is superimposed by voltage divider rectification in a method for detecting the status of the relay branch of a three-phase meter according to an embodiment of the present invention.
[0030] Figure 13 This is a waveform diagram of the voltage between phase B and phase C after the three-phase 220VAC line voltage is superimposed by voltage divider rectification in a relay branch status detection method of a three-phase meter according to an embodiment of the present invention.
[0031] Figure 14 This is a schematic diagram of a relay branch status detection device for a three-phase meter in one embodiment of the present invention;
[0032] Figure 15 This is a schematic diagram of a computer-readable storage medium according to an embodiment of the present invention. Detailed Implementation
[0033] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
[0034] In one embodiment, such as Figure 1 As shown, a method for detecting the status of a relay branch in a three-phase electricity meter is provided, comprising the following steps:
[0035] S01: Obtain the superimposed digital voltage signal of each phase branch of the three-phase meter relay.
[0036] In this embodiment, the back-end detection circuit diagram of the three-phase meter relay is shown in Figure 2. LINA1, LINB1, and LINC1 are the A-phase, B-phase, and C-phase voltages output from the back-end of the relay, respectively. Specifically, the A-phase voltage is divided by two resistors R1 and R2, each with a resistance of 120kΩ, and then half-wave rectified by diode D1 to obtain the rectified A-phase voltage signal. The B-phase voltage is divided by two resistors R3 and R4, each with a resistance of 240kΩ, and then half-wave rectified by diode D2 to obtain the rectified B-phase voltage signal. The C-phase voltage is divided by two resistors R10 and R11, each with a resistance of 330kΩ, and then half-wave rectified by diode D3 to obtain the rectified C-phase voltage signal.
[0037] The rectified phase A, phase B, and phase C voltage signals are superimposed at the same node to obtain the superimposed three-phase voltage signal. This superimposed signal is then connected to the neutral line via a voltage divider network consisting of two 240 kΩ resistors, R5 and R7, and a 5.1 kΩ resistor, R9, to achieve voltage proportional adjustment. The divided signal is output from across resistor R9 and fed into a TP5532 operational amplifier U1 for impedance matching, resulting in the matched three-phase voltage signal.
[0038] In this example, the op-amp is configured as a voltage follower to achieve impedance matching between the preamplifier and the subsequent circuitry. Because the voltage follower has extremely high input impedance (close to ideal infinity), it draws almost no current from the preamplifier voltage divider circuit. This ensures that the voltage distribution ratio of the voltage divider circuit is unaffected by the subsequent circuitry, maintaining signal accuracy. Furthermore, the voltage follower has extremely low output impedance (close to ideal 0Ω), making it a potential ideal voltage source. When driving subsequent circuitry (such as a metering chip), the output voltage remains stable even if the load impedance changes (e.g., fluctuations in the chip's input impedance).
[0039] Subsequently, the matched three-phase voltage signals pass through a first-order low-pass filter circuit consisting of a 100 Ω resistor R8 and a 10 nF capacitor C1, effectively filtering out high-frequency interference components to obtain the filtered three-phase voltage signals. Then, this filtered three-phase voltage signal undergoes overvoltage protection via a unidirectional transient voltage suppressor diode (TVS1) of model SMF36A to prevent damage to subsequent circuits from surge voltage and electrostatic discharge. Finally, the filtered three-phase voltage signals are sent to the input pin of the same analog-to-digital converter (ADC) for analog-to-digital conversion, resulting in a superimposed digital voltage signal. This superimposed digital voltage signal is then transmitted to the microcontroller unit (MCU) for subsequent status judgment. This input pin is a general-purpose input / output (GPIO) port. This GPIO port has configurable input / output functions and can be programmed in software for various purposes, facilitating signal sampling and status judgment by the microcontroller.
[0040] In this example, the unidirectional transient voltage suppressor diode TVS1 is in a high-resistance state and does not conduct under normal operating voltage. When a transient high voltage occurs in the circuit, the unidirectional transient voltage suppressor diode TVS1 quickly breaks down and conducts, clamping the voltage within a safe range and absorbing the surge current (peak pulse current IPP) to protect the sensitive components in the subsequent stage. After the surge disappears, the unidirectional transient voltage suppressor diode TVS1 automatically returns to the high-resistance state without affecting the normal operation of the circuit.
[0041] In this example, when the three-phase voltages of phases A, B, and C are all 220VAV line voltages, they exhibit the following characteristics in their respective phases: Figure 3 The different voltage waveforms shown are as follows. These three phase voltages are divided by resistors of different resistance values, then rectified and superimposed, ultimately forming the following waveforms on corresponding phases: Figure 4 The different composite voltage waveforms are shown.
[0042] In this example, once the microcontroller controls the relay to close, it immediately activates the Analog-to-Digital Converter (ADC) and Direct Memory Access (DMA) functions. The ADC converts the acquired analog signal into a digital signal, while the DMA automatically transfers the converted data from the ADC to memory. This entire process requires no CPU intervention, effectively improving system efficiency. The system continuously acquires the superimposed voltage obtained after voltage division processing at the ADC output port, obtaining its digital signal, which is the superimposed voltage digital signal. Using DMA technology, the system transmits 200 sample points of the superimposed voltage digital signal stored in the buffer to the preprocessing unit in batches every 10ms for subsequent preprocessing operations.
[0043] S02: Based on the superimposed digital voltage signal, obtain the voltage peak value of each phase branch and the timestamp corresponding to the voltage peak value.
[0044] In this example, after receiving the superimposed digital voltage signal obtained in step S01, the microcontroller will preprocess the data. The preprocessing specifically includes the following steps:
[0045] Convert the voltage digital signal obtained by voltage division and superposition into the actual superimposed voltage value (unit: V). For example... Figure 3 The figure shows the curve of the analog voltage signal before the three-phase voltage enters the voltage divider circuit.
[0046] 2) A 3-point sliding window mean filter is used to eliminate high-frequency noise (such as electromagnetic interference generated by relay operation) that is not filtered out in the first-order low-pass filter circuit composed of resistor R8 and capacitor C1. The specific calculation formula is as follows:
[0047]
[0048] in, This represents the actual superimposed voltage value after mean filtering at point n. This represents the actual superimposed voltage value at point n-1. This represents the actual superimposed voltage value at point n. This is the actual superimposed voltage value at point n+1.
[0049] In this example, the peak voltage of each phase branch and its corresponding timestamp are extracted from the actual superimposed voltage value sequence after mean filtering. Specifically, the voltage peak is identified by comparing the mean-filtered actual superimposed voltage value with a preset peak determination threshold. This peak determination threshold is determined based on the amplitude characteristics and voltage division ratio of the three-phase voltage, and its calculation formula is as follows:
[0050]
[0051] in, This is an adjustment parameter; it can be set to 90%.
[0052] In this example, according to... Figure 2 Given the circuit structure shown, calculate the voltage division ratio of each phase branch. For example, the voltage division ratio of phase A = R9 / (R1 + R2 + R5 + R7) ≈ 5.1K / (120K + 120K + 240K + 240K) ≈ 0.00708, the voltage division ratio of phase B = R9 / (R3 + R4 + R5 + R7) ≈ 5.1K / (240K + 240K + 240K + 240K) ≈ 0.00531, and the voltage division ratio of phase C = R9 / (R10 + R11 + R5 + R7) ≈ 5.1K / (330K + 330K + 240K + 240K) ≈ 0.00465.
[0053] like Figures 5-7 As shown, based on the calculation formulas for the peak voltage thresholds of each phase, when the three-phase line voltage is 90VAC, the peak voltage threshold for phase A is 0.8V, for phase B it is 0.6V, and for phase C it is 0.5V. When the three-phase line voltage is 220VAC, the peak voltage threshold for phase A is 2V, for phase B it is 1.6V, and for phase C it is 1.3V. When the three-phase line voltage is 280VAC, the peak voltage threshold for phase A is 2.5V, for phase B it is 1.9V, and for phase C it is 1.6V.
[0054] Ultimately, as Figure 4 As shown, when the three-phase line voltage is 220VAC, the minimum value of the peak voltage judgment threshold of each phase is selected as 1.3V, which is used as the unified preset peak judgment threshold. The method for judging the voltage peak is as follows: when the actual superimposed voltage value (2.19V) after mean filtering is greater than or equal to the preset threshold (1.3V), and the voltage value of the sampling point is higher than the voltage value of the adjacent sampling points after mean filtering in the local range, the point (2.19V) is judged as a valid peak, and the corresponding timestamp is recorded as 4.98ms. The number of peaks and their corresponding amplitudes are identified and counted within one cycle. Under normal circumstances, three periodic peaks should be generated after the three-phase voltage superposition, which correspond to the voltage peaks after rectification of phase A, phase B and phase C respectively. The system will store the peak sequence (such as peak_array[3] = {V_A, V_B, V_C}) and the corresponding peak occurrence timestamp sequence (time_stamp[3] = {T_A, T_B, T_C}) for subsequent analysis and processing.
[0055] The effective peak values and their timestamps identified by the above method are used as the voltage peak values and corresponding timestamps of each phase branch.
[0056] S03: Based on the voltage peak value, the timestamp, and the preset state determination conditions, the state result of the three-phase meter relay branch is obtained.
[0057] In this example, the preset state determination conditions refer to a series of logical determination conditions pre-set based on the electrical characteristics of the three-phase meter relay branch under different operating states, used to determine its opening / closing state, phase loss state, or phase sequence state. These conditions typically include key parameters such as voltage threshold range, number of peak values within a cycle, and peak amplitude variation trend, combined with corresponding timestamp information to achieve accurate identification of the relay's operating state. By comparing and analyzing the real-time collected voltage peak data and its timestamp with the preset conditions, the system can automatically and accurately determine the current operating state of the relay branch, such as closed, open, phase loss, or phase sequence error, thereby providing a reliable basis for fault diagnosis and operation monitoring.
[0058] This embodiment of a method for detecting the status of relay branches in a three-phase electricity meter includes acquiring the superimposed digital voltage signal of each phase branch of the three-phase electricity meter relay; extracting the voltage peak value and its corresponding timestamp of each phase branch based on the superimposed digital voltage signal; and determining and outputting the status result of each branch of the three-phase electricity meter relay by combining the voltage peak value, timestamp, and preset status judgment conditions. Compared with the prior art that only outputs a single comprehensive status signal, resulting in the system only being able to grasp the overall on / off status of the three-phase power supply and unable to achieve individual identification and monitoring of the voltage status of each phase, this invention, by accurately extracting the peak value of each phase voltage and its corresponding timestamp for discrimination and analysis, can not only achieve effective verification of the on / off status of the relay back end, but also support the diagnosis of phase loss faults and the identification of phase sequence errors in the three-phase power supply. The detection dimension is improved from the traditional overall judgment to single-phase level precise positioning, significantly enhancing the fineness and accuracy of status monitoring.
[0059] Optionally, in step S03, that is, obtaining the state result of the three-phase meter relay branch based on the voltage peak value, the timestamp, and the preset state determination conditions, the following steps are included:
[0060] S201: Obtain the opening and closing operation status signal of the relay of the three-phase meter.
[0061] In this embodiment, the opening and closing operation status signal is used to reflect the open or closed position status of the three-phase meter relay contacts. When the system detects that the relay execution contact is open, it generates and sends an opening and closing operation status signal indicating the open state to the microprocessor; similarly, when it detects that the relay execution contact is closed, it generates and sends an opening and closing operation status signal indicating the closed state to the microprocessor.
[0062] S202: Based on the superimposed digital voltage signal, the actual three-phase superimposed voltage value is obtained.
[0063] In this embodiment, the voltage digital signal after voltage division and superposition is converted into the actual superimposed voltage value, and a 3-point sliding window mean filter is used to eliminate high-frequency noise (such as electromagnetic interference generated by relay operation) that is not filtered out in the first-order low-pass filter circuit composed of resistor R8 and capacitor C1.
[0064] S203: Based on the opening and closing operation status signal, the actual three-phase superimposed voltage value, the voltage peak value, and the preset opening and closing status judgment conditions, the opening and closing status result of the three-phase meter relay branch is obtained.
[0065] In this embodiment, the opening and closing status determination condition refers to a set of preset conditions that accurately reflect the actual operating status of the relay by establishing a set of logical rules based on the correlation between electrical parameters (actual three-phase superimposed voltage value and voltage peak value) and mechanical status (opening and closing operation status signal) and combined with the operating rules of the power system. The actual three-phase superimposed voltage value is the actual superimposed voltage value after mean filtering.
[0066] This embodiment presents a method for detecting the status of a relay branch in a three-phase electricity meter. It acquires the opening and closing operation status signals of the three-phase meter relays, the actual superimposed three-phase voltage values, and combines these with the voltage peak value and preset judgment conditions to comprehensively determine the opening and closing status. This method uses electrical quantities (such as superimposed voltage values and voltage peak values) to verify the validity of mechanical action signals (i.e., opening and closing operation status signals), achieving accurate identification of the actual operating status of the relays. Compared to traditional methods that rely solely on switching signals, this method effectively avoids misjudgments caused by relay mechanical failures or false signal alarms, significantly improving the accuracy and reliability of detection, thereby ensuring the operational safety and reliability of the power system.
[0067] Optionally, step S203, namely the preset opening and closing state determination condition, specifically includes the following steps:
[0068] S301: The opening and closing operation status signals include opening operation status and closing operation status.
[0069] In this embodiment, the tripping operation state indicates that the circuit breaker contacts are open, the circuit is physically isolated, and the current is interrupted. The closing operation state indicates that the circuit breaker contacts are closed, the circuit is connected, and the current can flow.
[0070] S302: Within a preset duration, if the actual three-phase superimposed voltage values are all less than the preset neutral line voltage threshold, and the opening / closing operation status signal is the opening operation status, then the relay of the three-phase meter is determined to be in a normal opening state; if the actual three-phase superimposed voltage values are all less than the preset neutral line voltage threshold, and the opening / closing operation status signal is the closing operation status, then the relay of the three-phase meter is determined to be in a sticking fault state.
[0071] In this embodiment, the preset duration range is set to 100ms. If, within this time period, the actual three-phase superimposed voltage value is continuously less than the preset neutral voltage threshold, and the opening / closing operation status signal indicates the opening state (i.e., the relay has not performed the tripping operation), then it is determined that the relay of the three-phase meter is in a normal opening state; if, within the same time period, the actual three-phase superimposed voltage value is continuously lower than the neutral voltage threshold, but the opening / closing operation status signal shows the closing state (i.e., the relay has performed the tripping operation), then it is determined that the relay has a sticking fault.
[0072] S303: If the sequence of voltage peaks contains at least two sets of three-phase superimposed features, and the switching operation status signal is a switching operation status, then the relay of the three-phase meter is determined to be in a normal switching state.
[0073] In this embodiment, the three-phase superposition characteristic refers to the fact that when the three-phase voltages are superimposed through a voltage divider circuit, the difference in the voltage divider resistance of each phase results in three periodic peak values of different amplitudes after the three-phase voltages are superimposed. These peak values reflect the unbalanced characteristics of the phase voltages during the superposition process and have a clear periodic variation pattern. If the detected voltage peak sequence contains at least two complete sets of three-phase superposition characteristics (i.e., each set contains three periodic peak values), and the relay performs a tripping operation, then it can be determined that the relay of the three-phase meter is in a normal closing state.
[0074] This embodiment of a method for detecting the status of a relay branch in a three-phase electricity meter not only relies on the status signals from opening and closing operations, but also integrates the actual superimposed three-phase voltage values and voltage peak sequences for multi-dimensional joint judgment. Through this cross-verification mechanism, it can effectively identify relay faults (such as contact adhesion) or abnormal situations like false alarms, avoiding misjudgments and significantly improving the accuracy and reliability of relay status identification.
[0075] Optionally, in step S03, that is, obtaining the state result of the three-phase meter relay branch based on the voltage peak value, the timestamp, and the preset state determination conditions, the following steps are included:
[0076] S401: Extract the three-phase superposition feature from the sequence of voltage peaks.
[0077] In this embodiment, the three-phase superposition characteristic refers to the fact that when the three-phase voltages are superimposed through a voltage divider circuit, the difference in the voltage divider resistance of each phase results in three periodic peak values of different amplitudes after the three-phase voltages are superimposed. These peak values reflect the unbalanced characteristics of the phase voltages during the superposition process and exhibit a clear periodic variation pattern.
[0078] S402: Extract the peak values and amplitudes of each peak value from the three-phase superposition features, and count the total number of peak values.
[0079] In this embodiment, the peak value and its corresponding amplitude of the three-phase superposition feature in step S401 are extracted, and the total number of peak values in the feature is counted.
[0080] S403: Based on the amplitude of each peak value, the total number of peak values, and the preset phase failure condition, the phase failure result of the three-phase meter relay branch is obtained.
[0081] In this embodiment, the preset phase loss condition refers to the preset condition for identifying the phase loss state of the three-phase meter relay branch by analyzing the superposition characteristics of the three-phase voltages (such as the amplitude of the peak value and the total number of peak values). Phase loss refers to the complete or partial loss of voltage or current in one or more phases in a three-phase circuit, causing the originally symmetrical three-phase operation state to change into an asymmetrical operation state.
[0082] This embodiment presents a method for detecting the status of a relay branch in a three-phase meter. It fuses the peak voltage sequences of each phase to construct a three-phase superimposed feature, and then identifies abnormal states by analyzing the pattern changes in the peak distribution. This method can effectively capture more complex dynamic features in the voltage waveform, improving the sensitivity and accuracy of detecting phase loss faults, thereby achieving more reliable and stable relay branch status detection.
[0083] Optionally, step S403, i.e., the phase loss state determination condition, includes the following steps:
[0084] S501: If the total number of peak values is less than 3 within the same sampling period, the three-phase meter relay branch is determined to be in a phase-off state.
[0085] When the relay is normally closed, due to the different voltage divider resistors in phases A, B, and C of the hardware circuit, the peak amplitudes of the voltages after voltage division are fixed and follow a fixed order. For example, the voltage amplitude of phase A (V_A) > the voltage amplitude of phase B (V_B) > the voltage amplitude of phase C (V_C). Figure 8 As shown. When all three phase voltages are 220V AC line voltages, the approximate voltages after voltage division can be calculated based on the voltage division coefficients: V_A ≈ 1.8V, V_B ≈ 1.2V, V_C ≈ 0.8V.
[0086] Based on the above-mentioned correspondence pattern of peak amplitude, if the number of detected peaks is less than 3 within the same sampling period, for example: Figures 9-11 As shown, if only one peak is missing (e.g., only V_A and V_B are detected, but V_C is not detected), or two peaks are missing (e.g., only V_A is detected, but V_B and V_C are not detected), or none of the three peaks are detected (V_A, V_B, and V_C are all missing), then it is determined that a phase failure has occurred in the corresponding phase of the three-phase meter relay branch (e.g., phase C is missing), and the corresponding fault type is recorded.
[0087] S502: If the total number of peak values is equal to 3, and the amplitude of the peak value is less than the preset amplitude threshold, then the three-phase meter relay branch is determined to be in a phase-off state.
[0088] In this implementation, the preset amplitude threshold is set to 50% of the normal amplitude. According to the corresponding pattern of the peak amplitude, if the number of peaks detected is 3 and there are no missing peaks within the same sampling period, but the amplitude of one of the peaks is lower than 50% of the normal amplitude (for example, V_B<0.6V), it is determined that the corresponding phase in the three-phase meter relay branch has a phase failure (such as phase B failure), and the corresponding fault type is recorded.
[0089] This embodiment of a method for detecting the status of a relay branch in a three-phase meter uses two conditions to determine phase loss: it considers both obvious anomalies in the number of peak values (less than 3) and situations where the number of peak values is normal (equal to 3) but the amplitude is too low (possibly due to a severely low voltage in one phase). This dual criterion reduces the possibility of missed or false detections.
[0090] Optionally, in step S03, that is, obtaining the state result of the three-phase meter relay branch based on the voltage peak value, the timestamp, and the preset state determination conditions, the following steps are included:
[0091] S601: Extract the three-phase superposition feature from the sequence of voltage peaks.
[0092] In this embodiment, the three-phase superposition feature refers to that when the three-phase voltages are superimposed through a voltage dividing circuit, due to the differences in the voltage dividing resistors of each phase, three periodic peaks with different amplitudes are generated after the three-phase voltages are superimposed. These peaks reflect the unbalanced characteristics of each phase voltage during the superposition process and have an obvious periodic variation law.
[0093] S602: Extract the peaks in the three-phase superposition feature and the amplitudes of each peak.
[0094] In this embodiment, extract the peaks of the three-phase superposition feature in step S601, and obtain the corresponding amplitudes and timestamps.
[0095] S603: According to the amplitudes of each peak and the preset phase sequence state determination condition, obtain the phase sequence state result of the relay branch of the three-phase electric meter.
[0096] In this embodiment, the preset phase sequence state determination condition refers to the preset condition for identifying the phase sequence state (such as reverse phase sequence connection) of the relay branch of the three-phase electric meter by analyzing the amplitude superposition feature of the three-phase voltage signals (that is, the amplitudes of the peaks of each phase voltage).
[0097] A method for detecting the state of the relay branch of a three-phase electric meter in this embodiment realizes the timely detection of abnormal phase sequence and effectively guarantees the safe and stable operation of the power system by extracting and quantifying the change of the amplitude characteristics of the peaks of each phase voltage, constructing a discriminative index, and triggering an alarm when the index meets the preset conditions.
[0098] Optionally, in step S603, the preset phase sequence state determination condition includes the following steps:
[0099] S701: If within the same sampling period, the amplitudes of each peak do not meet the preset three-phase amplitude sorting condition, it is determined that the relay branch of the three-phase electric meter is in a phase sequence error state.
[0100] In this embodiment, as Figure 12 shown, when the relay is normally closed, due to the different voltage dividing resistors of phase A, phase B, and phase C in the hardware circuit, the peak amplitudes obtained after the voltage division of each phase voltage are fixed values and have a fixed size sorting rule. The preset three-phase amplitude sorting condition can be set as: If the timestamp order of the three-phase peaks satisfies: phase A timestamp \(T_A <\) phase B timestamp \(T_B <\) phase C timestamp \(T_C\), and the size order of the amplitudes of the three-phase peaks satisfies: phase A voltage amplitude \(V_A >\) phase B voltage amplitude \(V_B >\) phase C voltage amplitude \(V_C\), then the phase sequence of the relay branch of the three-phase electric meter is correct.
[0101] According to the correspondence between the peak amplitude and the timestamp, if within the same sampling period, the amplitudes of the three-phase peaks do not meet the above-mentioned three-phase amplitude sorting conditions, when any of the following situations occurs, it is determined that the phase sequence is incorrect:
[0102] 1) As Figure 13 shown, if the peak timestamp order is T_A < T_C < T_B, and the amplitudes satisfy V_A > V_C > V_B, then it is determined that the phase sequence of phases B and C is reversed.
[0103] 2) If the peak timestamp order is T_C < T_B < T_A, and the amplitudes satisfy V_C > V_B > V_A, then it is determined that the phase sequence of phases A and C is reversed.
[0104] 3) If the peak timestamp order is T_B < T_A < T_C, and the amplitudes satisfy V_B > V_A > V_C, then it is determined that the phase sequence of phases A and B is reversed.
[0105] 4) If the peak timestamp order is T_B < T_C < T_A, and the amplitudes satisfy V_B > V_C > V_A, then it is determined that the phase sequence of phases A, B, and C is reversed.
[0106] 5) If the peak timestamp order is T_C < T_A < T_B, and the amplitudes satisfy V_C > V_A > V_B, then it is determined that the phase sequence of phases A, B, and C is reversed.
[0107] All of the above five situations indicate that the actual phase sequence does not match the standard sequence, so it is determined that the phase sequence is incorrect.
[0108] In this embodiment, an anti-misjudgment mechanism is additionally provided: only when within three consecutive sampling periods, the amplitudes of the three-phase peaks do not meet the preset three-phase amplitude sorting conditions, and the phase sequence error situations detected each time are the same, is it determined that the relay branch of the three-phase electric meter is in a phase sequence error state. This design effectively avoids misjudgment caused by single-time noise interference and improves the accuracy and reliability of judgment.
[0109] A method for detecting the state of the relay branch of a three-phase electric meter in this embodiment, based on the inherent difference in the peak amplitudes of three-phase voltages in the positive sequence and negative sequence (phase sequence reversed) states, transforms the complex phase relationship judgment into a reliable amplitude size sorting judgment. Only the relative sizes of the three-phase voltage peaks need to be compared, without complex phase calculations, significantly reducing the algorithm calculation complexity. This method effectively realizes the efficient and accurate diagnosis of the phase sequence state and has good practicability and reliability.
[0110] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.
[0111] In one embodiment, a relay branch status detection device for a three-phase electricity meter is provided, which corresponds one-to-one with the relay branch status detection method for a three-phase electricity meter described in the above embodiments. For example... Figure 14 As shown, the relay branch status detection device of this three-phase electricity meter includes a voltage acquisition module 101, a peak value extraction module 102, and a status result output module 103. Detailed descriptions of each functional module are as follows:
[0112] The voltage acquisition module 101 is used to acquire the superimposed digital voltage signal of each phase branch of the three-phase meter relay.
[0113] The peak extraction module 102 is used to obtain the voltage peak value of each phase branch and the timestamp corresponding to the voltage peak value based on the superimposed voltage digital signal.
[0114] The status result output module 103 is used to obtain the status result of the three-phase meter relay branch based on the voltage peak value, the timestamp, and the preset status judgment conditions.
[0115] Optionally, the status result output module 103 specifically includes:
[0116] The circuit breaker operation status signal acquisition submodule is used to acquire the circuit breaker operation status signals of the relays of the three-phase electricity meter.
[0117] The actual three-phase superimposed voltage conversion submodule is used to obtain the actual three-phase superimposed voltage value based on the superimposed voltage digital signal.
[0118] The circuit breaker opening and closing status result output submodule is used to obtain the circuit breaker opening and closing status result of the three-phase meter relay branch based on the circuit breaker opening and closing operation status signal, the actual three-phase superimposed voltage value, the voltage peak value, and the preset circuit breaker opening and closing status judgment conditions.
[0119] Optionally, the circuit breaker opening / closing status result output submodule specifically includes:
[0120] A condition unit is used for the opening and closing operation status signals, including opening operation status and closing operation status;
[0121] The tripping determination unit is used to determine that the relay of the three-phase meter is in a normal tripping state if, within a preset time range, the actual three-phase superimposed voltage value is less than a preset neutral line voltage threshold and the tripping / closing operation status signal is in the tripping operation state; and if, within a preset time range, the actual three-phase superimposed voltage value is less than the preset neutral line voltage threshold and the tripping / closing operation status signal is in the closing operation state, the relay of the three-phase meter is in a sticking fault state.
[0122] The closing determination unit is used to determine that the relay of the three-phase meter is in a normal closing state if the sequence of voltage peaks contains at least two sets of three-phase superimposed features and the opening and closing operation status signal is a closing operation state.
[0123] Optionally, the status result output module 103 specifically includes:
[0124] The three-phase superposition feature submodule is used to extract the three-phase superposition features from the sequence of voltage peaks.
[0125] The peak extraction submodule is used to extract the peak values and amplitudes of each peak value from the three-phase superposition features, and to count the total number of peak values.
[0126] The phase failure status result output submodule is used to obtain the phase failure status result of the three-phase meter relay branch based on the amplitude of each peak, the total number of peaks, and the preset phase failure status judgment conditions.
[0127] Optionally, the phase failure state result output submodule specifically includes:
[0128] The first phase failure determination unit is used to determine that the three-phase meter relay branch is in a phase failure state if the total number of peak values is less than 3 within the same sampling period.
[0129] The second phase failure determination unit is used to determine that the three-phase meter relay branch is in a phase failure state if the total number of peak values is equal to 3 and the amplitude of the peak value is less than a preset amplitude threshold.
[0130] Optionally, the status result output module 103 specifically includes:
[0131] The phase sequence three-phase superposition feature extraction submodule is used to extract the three-phase superposition features from the sequence of voltage peaks.
[0132] The phase sequence peak extraction submodule is used to extract the peak values and amplitudes of each peak value from the three-phase superposition features.
[0133] The phase sequence status result output submodule is used to obtain the phase sequence status result of the three-phase meter relay branch based on the amplitude of each peak and the preset phase sequence status determination conditions.
[0134] Optionally, the phase sequence state result output submodule specifically includes:
[0135] The phase sequence error determination unit is used to determine that the three-phase meter relay branch is in a phase sequence error state if the amplitude of each peak does not meet the preset three-phase amplitude sorting condition within the same sampling period.
[0136] This invention provides a relay branch status detection device for a three-phase electricity meter, comprising: acquiring the superimposed digital voltage signal of each phase branch of the three-phase electricity meter relay; extracting the voltage peak value and its corresponding timestamp of each phase branch based on the superimposed digital voltage signal; and determining and outputting the status result of each branch of the three-phase electricity meter relay by combining the voltage peak value, timestamp, and preset status judgment conditions. Compared with the prior art that only outputs a single comprehensive status signal, resulting in the system only being able to grasp the overall on / off status of the three-phase power supply and unable to achieve individual identification and monitoring of the voltage status of each phase, this invention, by accurately extracting the peak value of each phase voltage and its corresponding timestamp for discrimination and analysis, can not only achieve effective verification of the on / off status of the relay back end, but also support the diagnosis of phase loss faults and the identification of phase sequence errors in the three-phase power supply. The detection dimension is improved from the traditional overall judgment to single-phase level precise positioning, significantly enhancing the fine granularity and accuracy of status monitoring.
[0137] Specific limitations regarding the relay branch status detection device for three-phase electricity meters can be found in the above-described limitations on the relay branch status detection method for three-phase electricity meters, and will not be repeated here. Each module in the aforementioned relay branch status detection device for three-phase electricity meters can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.
[0138] In one embodiment, such as Figure 15 As shown, a computer-readable storage medium is provided, on which a computer program is stored. When executed by a processor, the computer program implements the relay branch status detection method of the three-phase meter in the above embodiment, for example... Figure 1 S01-S03, as shown, will not be described again here to avoid repetition. Alternatively, when this computer program is executed by a processor, it implements the functions of each module / unit in this embodiment of the relay branch status detection device for a three-phase electricity meter, for example... Figure 14 The functions of the voltage acquisition module 101, peak extraction module 102, and status result output module 103 shown are not described again here to avoid repetition.
[0139] In one embodiment, an electricity meter is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the relay branch status detection method for a three-phase electricity meter as described in the above embodiment, for example... Figure 1 S01-S03, as shown, will not be described again here to avoid repetition. Alternatively, when the processor executes the computer program, it implements the functions of each module / unit in this embodiment of the relay branch status detection device for a three-phase electricity meter, for example... Figure 14The functions of the voltage acquisition module 101, peak extraction module 102, and status result output module 103 shown are not described again here to avoid repetition.
[0140] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.
Claims
1. A method for detecting the status of a relay branch in a three-phase electricity meter, characterized in that, The state detection method includes: Obtain the superimposed digital voltage signal of each phase branch of the three-phase meter relay; Based on the superimposed digital voltage signal, the peak voltage of each phase branch and the timestamp corresponding to the peak voltage are obtained; Based on the voltage peak value, the timestamp, and the preset state determination conditions, the state result of the three-phase meter relay branch is obtained; The process of obtaining the state result of the three-phase meter relay branch based on the voltage peak value, the timestamp, and preset state determination conditions includes: Extract the three-phase superposition features from the sequence of voltage peaks; Extract the peak values and amplitudes of each peak value from the three-phase superposition features, and count the total number of peak values; Based on the amplitude of each peak value, the total number of peak values, and the preset phase failure condition, the phase failure status result of the three-phase meter relay branch is obtained. The conditions for determining the phase loss state include: If the total number of peak values is less than 3 within the same sampling period, the three-phase meter relay branch is determined to be in a phase-out state. If the total number of peak values is equal to 3, and the amplitude of the peak value is less than a preset amplitude threshold, then the three-phase meter relay branch is determined to be in a phase-out state.
2. The method for detecting the status of the relay branch of a three-phase meter according to claim 1, characterized in that, The process of obtaining the state result of the three-phase meter relay branch based on the voltage peak value, the timestamp, and preset state determination conditions includes: Obtain the opening and closing operation status signals of the relays of the three-phase electricity meter; Based on the superimposed digital voltage signal, the actual three-phase superimposed voltage value is obtained; Based on the opening and closing operation status signal, the actual three-phase superimposed voltage value, the voltage peak value, and the preset opening and closing status determination conditions, the opening and closing status result of the three-phase meter relay branch is obtained.
3. The method for detecting the status of the relay branch of a three-phase meter according to claim 2, characterized in that, The preset conditions for determining the opening and closing states include: The opening and closing operation status signals include opening operation status and closing operation status; Within a preset duration, if the actual three-phase superimposed voltage values are all less than the preset neutral line voltage threshold, and the opening / closing operation status signal is the opening operation status, then the relay of the three-phase meter is determined to be in a normal opening state; if the actual three-phase superimposed voltage values are all less than the preset neutral line voltage threshold, and the opening / closing operation status signal is the closing operation status, then the relay of the three-phase meter is determined to be in a sticking fault state. If the sequence of voltage peaks contains at least two sets of three-phase superimposed features, and the switching operation status signal is a switching operation status, then the relay of the three-phase meter is determined to be in a normal switching state.
4. The method for detecting the status of the relay branch of a three-phase meter according to claim 1, characterized in that, The process of obtaining the state result of the three-phase meter relay branch based on the voltage peak value, the timestamp, and preset state determination conditions includes: Extract the three-phase superposition features from the sequence of voltage peaks; Extract the peak values and amplitudes of each peak value from the three-phase superposition features; Based on the amplitude of each peak value and the preset phase sequence state determination conditions, the phase sequence state result of the three-phase meter relay branch is obtained.
5. The method for detecting the status of the relay branch of a three-phase meter according to claim 4, characterized in that, The preset phase sequence state determination conditions include: If the amplitude of each peak value does not meet the preset three-phase amplitude sorting condition within the same sampling period, the three-phase meter relay branch is determined to be in a phase sequence error state.
6. A relay branch status detection device for a three-phase electricity meter, characterized in that, The state detection device includes: The voltage acquisition module is used to acquire the superimposed digital voltage signal of each phase branch of the three-phase meter relay; The peak extraction module is used to obtain the voltage peak value of each phase branch and the timestamp corresponding to the voltage peak value based on the superimposed voltage digital signal. The status result output module is used to obtain the status result of the three-phase meter relay branch based on the voltage peak value, the timestamp, and the preset status judgment conditions; The status result output module includes: The three-phase superposition feature submodule is used to extract the three-phase superposition features from the sequence of voltage peaks; The peak extraction submodule is used to extract the peak values and amplitudes of each peak value from the three-phase superposition features, and to count the total number of peak values. The phase failure status result output submodule is used to obtain the phase failure status result of the three-phase meter relay branch based on the amplitude of each peak, the total number of peaks, and the preset phase failure status judgment conditions. The phase loss status result output submodule includes: The first phase failure determination unit is used to determine that the three-phase meter relay branch is in a phase failure state if the total number of peak values is less than 3 within the same sampling period. The second phase failure determination unit is used to determine that the three-phase meter relay branch is in a phase failure state if the total number of peak values is equal to 3 and the amplitude of the peak value is less than a preset amplitude threshold.
7. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the relay branch status detection method of the three-phase meter according to any one of claims 1 to 5.
8. An electricity meter, characterized in that, The meter is used to implement the relay branch status detection method of the three-phase meter according to any one of claims 1 to 5.