Method and device for processing fault current of electric energy meter and electric energy meter

Abstract

The invention provides an electric energy meter fault current processing method and device and an electric energy meter, and relates to the technical field of electric power grids. The real-time current, the active power, the reactive power and the power factor of the electric energy meter are analyzed to determine whether the electric energy meter is in a creeping state in the current period, namely whether the electric energy meter has a fault, and when the electric energy meter is in the creeping state in the current period, the metering current of the electric energy meter in the current period is set to zero; the metering accuracy of the electric energy meter during no-load is ensured, and the technical problem of inaccurate metering of the electric energy meter during no-load is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power grid, and in particular to a method and device for processing fault current of an electric energy meter, and an electric energy meter. Background Art

[0002] The electric energy meter is a product closely related to people's livelihood. As a legal measuring instrument, its accuracy directly affects people's lives.

[0003] With the continuous updating of communication technology, a large number of carrier communication modules are widely used in electric energy meters. During the module communication process, the power line carrier will affect the electric energy meter and generate fault current. This current will make users question the metering accuracy of the electric energy meter. This kind of fault current occurs when the user cuts off the load, such as in an empty house. The user presses the button to turn the screen to check the current display screen on the meter LCD screen and finds that there is a current value. Therefore, the user suspects that the meter is not accurate and the electric energy meter has inaccurate measurement problems. Summary of the invention

[0004] The present invention provides a method and device for processing fault current of an electric energy meter and an electric energy meter, which can solve the technical problem of inaccurate measurement of the electric energy meter and improve the measurement accuracy of the electric energy meter.

[0005] In a first aspect, the present invention provides a method for processing fault current of an electric energy meter, the method comprising: detecting real-time parameters of a current cycle of the electric energy meter, the real-time parameters including real-time current, active power and reactive power; calculating the power factor of the current cycle based on the active power and reactive power; determining whether the current cycle of the electric energy meter is in a latent state based on the real-time parameters and the power factor; the latent state indicates that the real-time current of the current cycle is a fault current; if the current cycle of the electric energy meter is in a latent state, setting the metering current of the current cycle of the electric energy meter to zero.

[0006] In one possible implementation, based on real-time parameters and power factor, it is determined whether the current cycle of the electric energy meter is in a latent state, including: if the active power is less than the active threshold, the reactive power is less than the reactive threshold, and the power factor is less than the power factor threshold, then it is determined that the current cycle of the electric energy meter is in a latent state; if the active power is less than the active threshold, the reactive power is less than the reactive threshold, or the power factor is less than the power factor threshold, then based on the real-time current, it is determined whether the current cycle of the electric energy meter is in a latent state.

[0007] In one possible implementation, based on the real-time current, determining whether the electric energy meter is in a latent state in the current cycle includes: performing Fourier transform on the real-time current of the current cycle to obtain the effective values ​​of the fundamental current and each harmonic current of the current cycle; based on the effective values ​​of the fundamental current and each harmonic current, calculating the effective value of the total current of the current cycle; if the effective value of the fundamental current is zero and the effective value of the total current is not zero, determining that the electric energy meter is in a latent state in the current cycle.

[0008] In a possible implementation, whether the electric energy meter is in a latent state in a current cycle is determined based on the real-time current, including: if the effective value of the fundamental current is greater than zero, determining that the electric energy meter is not in a latent state in the current cycle.

[0009] In a possible implementation, the method further includes: if the electric energy meter is not in a latent state in a current cycle, storing the real-time current of the electric energy meter in the current cycle.

[0010] In the second aspect, an embodiment of the present invention provides a processing device for the fault current of an electric energy meter, the processing device comprising: a communication module and a processing module, the communication module being used to detect the real-time parameters of the current cycle of the electric energy meter, the real-time parameters including real-time current, active power and reactive power; the processing module being used to calculate the power factor of the current cycle based on the active power and reactive power; based on the real-time parameters and the power factor, determining whether the current cycle of the electric energy meter is in a latent state; the latent state characterizes that the real-time current of the current cycle is a fault current; if the current cycle of the electric energy meter is in a latent state, the metering current of the current cycle of the electric energy meter is set to zero.

[0011] In one possible implementation, the processing module is specifically used to determine whether the current cycle of the electric energy meter is in a latent state if the active power is less than the active threshold, the reactive power is less than the reactive threshold, and the power factor is less than the power factor threshold; if the active power is less than the active threshold, the reactive power is less than the reactive threshold, or the power factor is less than the power factor threshold, then based on the real-time current, determine whether the current cycle of the electric energy meter is in a latent state.

[0012] In one possible implementation, the processing module is specifically used to perform Fourier transform on the real-time current of the current cycle to obtain the effective values ​​of the fundamental current and each harmonic current of the current cycle; based on the effective values ​​of the fundamental current and each harmonic current, the effective value of the total current of the current cycle is calculated; if the effective value of the fundamental current is zero and the effective value of the total current is not zero, it is determined that the electric energy meter is in a latent state in the current cycle.

[0013] In a possible implementation, the processing module is specifically configured to determine that the electric energy meter is not in a latent state in a current cycle if the effective value of the fundamental current is greater than zero.

[0014] In a third aspect, an embodiment of the present invention provides an electric energy meter, which includes an electronic device, the electronic device includes a memory and a processor, the memory stores a computer program, and the processor is used to call and run the computer program stored in the memory to perform the steps of the method described in the first aspect and any possible implementation method of the first aspect.

[0015] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and wherein when the computer program is executed by a processor, the steps of the method described in the first aspect and any possible implementation method of the first aspect are implemented.

[0016] The present invention provides a method and device for processing fault current of an electric energy meter and an electric energy meter. The present invention analyzes the real-time current, active power, reactive power and power factor of the electric energy meter to determine whether the current cycle of the electric energy meter is in a dormant state, that is, whether the electric energy meter has a fault. When the current cycle of the electric energy meter is in a dormant state, the metering current of the current cycle of the electric energy meter is set to zero to ensure the metering accuracy of the electric energy meter when it is unloaded, thereby solving the technical problem of inaccurate metering when the electric energy meter is unloaded. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 It is a flow chart of a method for processing fault current of an electric energy meter provided by an embodiment of the present invention; Figure 2 It is a structural schematic diagram of a device for processing fault current of an electric energy meter provided by an embodiment of the present invention; Figure 3 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0020] In the description of the present invention, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, "at least one" and "plurality" refer to two or more. The words "first", "second", etc. do not limit the quantity and execution order, and the words "first", "second", etc. do not limit them to be different.

[0021] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way for easy understanding.

[0022] In addition, the terms "including" and "having" and any variations thereof mentioned in the description of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or modules is not limited to the listed steps or modules, but may optionally include other steps or modules that are not listed, or may optionally include other steps or modules that are inherent to these processes, methods, products or devices.

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the following will be described through specific embodiments in conjunction with the accompanying drawings of the present invention.

[0024] As described in the background technology, when the current electric energy meter is unloaded, there is a technical problem of no-load current and inaccurate measurement. In view of this technical problem, the no-load current in the electric energy meter is mainly caused by the modulation signal of the carrier, which causes the voltage and current to contain certain harmonic components. The metering chip is a full-wave metering method, and all harmonic components within the bandwidth are accounted for.

[0025] Among them, the instantaneous voltage, current and power can be expressed as the sum of their harmonic components using Fourier transform.

[0026] The voltage and current formulas are expanded as follows: ; ; Where: is the real-time voltage at time t, is the real-time current at time t, is the effective value of the hth harmonic voltage, is the effective value of the hth harmonic current, is the hth harmonic angular velocity, is the harmonic order. is the voltage phase angle of the hth harmonic, is the current phase angle of the hth harmonic.

[0027] The effective value can be expressed by the following formula through derivation: ; in, is the effective value of voltage, is the effective value of the fundamental voltage, is the effective value of the hth harmonic voltage.

[0028] The active power P can be expressed as the sum of their fundamental active power and harmonic active power P=P1+Ph, where: ; ; in, is the fundamental active power, is the fundamental voltage, is the fundamental current, is the fundamental voltage phase angle, is the fundamental current phase angle. is the harmonic active power, is the hth harmonic voltage, is the hth harmonic current, is the phase angle of the hth harmonic voltage, is the phase angle of the hth harmonic current.

[0029] From the above expression of active power, we can see that power is obtained by multiplying the same frequency. Only when the voltage and current loops have components of the same frequency can power be obtained by multiplying them.

[0030] The fault current is mainly caused by the harmonic influence of voltage and current signals. On-site analysis shows that the current channel has a maximum current of 0.1A, and the manganese copper of the current channel is 250uΩ. The harmonic current of 0.1A is measured from the electric meter, and the harmonic influence is deduced to be 0.1A*250uΩ=25uV. When the same magnitude of influence is superimposed on the voltage channel, the electric meter has a voltage of 220V under normal circumstances. At this time, the voltage channel signal is 220mV, and the harmonic component of 25uV is converted to a voltage of 0.025V. At this time, the effective value of the voltage is: sqrt(220*220+0.025*0.025) V= 220.0000014V. From this point of view, the influence of voltage can be basically ignored. In this working condition, because there is no 50hz current, the 50hz fundamental power P1=0, and the harmonic component has a certain influence, and the maximum harmonic power is: P h=0.1A*0.025V = 0.0025W, total power P=P1+P h = 0.0025W.

[0031] From the above analysis, it can be seen that the modulation signal of power line carrier communication is a high-frequency signal, which is equivalent to continuous pulse group interference for the electric energy meter. The low-pass filter on the electric energy meter cannot effectively filter out all high-frequency signals completely; the input signal of the current channel is uV level when it is unloaded, and the high-frequency interference signal is superimposed and then amplified by the internal 16-fold ADC signal to produce a mV level current sampling signal. The instantaneous current value is obtained by reading the current register value of the metering chip by the MCU and multiplying it by the conversion coefficient. This value is displayed on the LCD screen, with a maximum harmonic component current value of 100mA. Due to this interference, the current signal generated by the electric energy meter is a high-frequency harmonic component, so the impact on active power and reactive power can be ignored, and it has no effect on the measurement accuracy of the electric energy meter.

[0032] In the embodiment of the present invention, the active power value, reactive power value and current in the electric energy meter are judged and processed. At the same time, the metering chip status register is added to the program to judge whether the active power and reactive power of the metering chip are in a latent state. The latent state is when the active power is less than a certain limit value, and the meter measures the electric energy again. When the active power and reactive power in the electric energy meter are both less than the latent threshold of the electric energy meter, the instantaneous current value obtained after the conversion of the current register in the metering chip read by the MCU is not 0. At this time, the instantaneous current value should be the fault current generated by the interference signal caused by carrier communication or other conduction or radio frequency interference. The software judges it as an abnormal current and performs zeroing processing, and the LCD screen does not display the existence of the current value.

[0033] Based on the above, if Figure 1 As shown, an embodiment of the present invention provides a method for processing fault current of an electric energy meter, and the method includes steps S101-S104.

[0034] S101, detecting real-time parameters of the current cycle of the electric energy meter.

[0035] In the embodiment of the present application, the real-time parameters include real-time current, active power and reactive power.

[0036] S102: Calculate the power factor of the current cycle based on the active power and the reactive power.

[0037] S103: Based on the real-time parameters and the power factor, determine whether the electric energy meter is in a latent state in the current cycle.

[0038] In the embodiment of the present application, the latent state indicates that the real-time current of the current cycle is a fault current.

[0039] As a possible implementation, if the active power is less than the active threshold, the reactive power is less than the reactive threshold, and the power factor is less than the power factor threshold, the embodiment of the present application determines that the electric energy meter is in a latent state in the current cycle; Exemplarily, the active power and reactive power are less than the starting limit of the power meter power, and the current power factor is less than the power factor judgment limit. If there is current at this time, it is regarded as a fault current, and the program processes it as 0.

[0040] Active power value P1, reactive power value P2, power factor COS, start judgment limit THP, power factor judgment limit THC, live wire current value I: P1<THP, P2<THP, COS<THC, then I=0.

[0041] As another possible implementation, if the active power is less than the active threshold, the reactive power is less than the reactive threshold, or the power factor is less than the power factor threshold, it is determined based on the real-time current whether the electric energy meter is in a latent state in the current cycle.

[0042] Exemplarily, the embodiment of the present invention can analyze the real-time current based on steps A1-A3 to determine whether the electric energy meter is in a latent state in the current cycle.

[0043] A1. Perform Fourier transform on the real-time current of the current cycle to obtain the effective value of the fundamental current and each harmonic current of the current cycle.

[0044] A2. Based on the effective values ​​of the fundamental current and each harmonic current, calculate the effective value of the total current in the current cycle.

[0045] A3. If the effective value of the fundamental current is zero and the effective value of the total current is not zero, it is determined that the electric energy meter is in a latent state in the current cycle.

[0046] Exemplarily, the collected current waveform data is subjected to Fourier transform to obtain the effective value of the fundamental current and each harmonic current. The fundamental current is I0, and each harmonic current is Ih: ; If the fundamental current I0=0, and the total current I rms If it is not 0, the current collected by the electric energy meter is considered to be a fault current, and the program processes the measured current I=0.

[0047] Exemplarily, if the effective value of the fundamental current is greater than zero, the embodiment of the present invention can determine that the electric energy meter is not in a latent state in the current cycle.

[0048] S104. If the electric energy meter is in a latent state in the current cycle, the metering current of the electric energy meter in the current cycle is set to zero.

[0049] Optionally, if the electric energy meter is not in a latent state in the current cycle, the embodiment of the present invention may store the real-time current of the electric energy meter in the current cycle.

[0050] The present invention provides a method for processing fault current of an electric energy meter. By analyzing the real-time current, active power, reactive power and power factor of the electric energy meter, it is determined whether the electric energy meter is in a latent state in the current cycle, that is, whether the electric energy meter has a fault. When the electric energy meter is in a latent state in the current cycle, the metering current of the electric energy meter in the current cycle is set to zero to ensure the metering accuracy of the electric energy meter when it is unloaded, thereby solving the technical problem of inaccurate metering when the electric energy meter is unloaded.

[0051] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0052] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0053] Figure 2 The schematic diagram of the structure of a device for processing fault current of an electric energy meter provided by an embodiment of the present invention is shown. The processing device 200 includes a communication module 201 and a processing module 202 .

[0054] The communication module 201 is used to detect the real-time parameters of the electric energy meter in the current cycle, and the real-time parameters include real-time current, active power and reactive power.

[0055] The processing module 202 is used to calculate the power factor of the current cycle based on the active power and the reactive power; based on the real-time parameters and the power factor, determine whether the electric energy meter is in a latent state in the current cycle; the latent state indicates that the real-time current of the current cycle is a fault current; if the electric energy meter is in a latent state in the current cycle, the metering current of the electric energy meter in the current cycle is set to zero.

[0056] Figure 3 Schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. Figure 3 As shown, the electronic device 300 includes: a processor 301, a memory 302, and a computer program 303 stored in the memory 302 and executable on the processor 301. When the processor 301 executes the computer program 303, the steps in the above-mentioned method embodiments are implemented, for example Figure 1 Alternatively, when the processor 301 executes the computer program 303, the functions of each module / unit in the above-mentioned device embodiments are realized, for example, Figure 2 The functions of the communication module 201 and the processing module 202 are shown.

[0057] Exemplarily, the computer program 303 may be divided into one or more modules / units, which are stored in the memory 302 and executed by the processor 301 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments that can implement specific functions, and the instruction segments are used to describe the execution process of the computer program 303 in the electronic device 300. For example, the computer program 303 may be divided into Figure 2 The communication module 201 and the processing module 202 are shown.

[0058] The processor 301 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0059] The memory 302 may be an internal storage unit of the electronic device 300, such as a hard disk or memory of the electronic device 300. The memory 302 may also be an external storage device of the electronic device 300, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 300. Further, the memory 302 may also include both an internal storage unit of the electronic device 300 and an external storage device. The memory 302 is used to store the computer program and other programs and data required by the terminal. The memory 302 may also be used to temporarily store data that has been output or is to be output.

[0060] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for processing fault current of an electric energy meter, characterized in that: include: Detecting real-time parameters of the current cycle of the electric energy meter, wherein the real-time parameters include real-time current, active power and reactive power; Calculating the power factor of the current cycle based on the active power and the reactive power; Based on the real-time parameter and the power factor, determining whether the electric energy meter is in a latent state in the current cycle; the latent state indicates that the real-time current in the current cycle is a fault current; If the electric energy meter is in a latent state in the current cycle, the metering current of the electric energy meter in the current cycle is set to zero.

2. The method for processing fault current of an electric energy meter according to claim 1, characterized in that: The determining, based on the real-time parameter and the power factor, whether the electric energy meter is in a latent state in a current cycle includes: If the active power is less than the active power threshold, the reactive power is less than the reactive power threshold, and the power factor is less than the power factor threshold, it is determined that the electric energy meter is in a latent state in the current cycle; If the active power is less than the active power threshold, the reactive power is less than the reactive power threshold, or the power factor is less than the power factor threshold, then based on the real-time current, it is determined whether the electric energy meter is in a latent state in the current cycle.

3. The method for processing fault current of an electric energy meter according to claim 1, characterized in that: The determining, based on the real-time current, whether the electric energy meter is in a latent state in a current cycle includes: Performing Fourier transformation on the real-time current of the current cycle to obtain the effective value of the fundamental current and each harmonic current of the current cycle; Based on the effective values ​​of the fundamental current and each harmonic current, calculate the effective value of the total current in the current cycle; If the effective value of the fundamental current is zero and the effective value of the total current is not zero, it is determined that the electric energy meter is in a latent state in the current cycle.

4. The method for processing fault current of an electric energy meter according to claim 3, characterized in that: The determining, based on the real-time current, whether the electric energy meter is in a latent state in a current cycle includes: If the effective value of the fundamental current is greater than zero, it is determined that the electric energy meter is not in a latent state in the current cycle.

5. The method for processing fault current of an electric energy meter according to claim 1, characterized in that: The method further comprises: If the electric energy meter is not in a latent state in the current cycle, the real-time current of the electric energy meter in the current cycle is stored.

6. A device for processing fault current of an electric energy meter, characterized in that: include: A communication module, used to detect real-time parameters of the current cycle of the electric energy meter, wherein the real-time parameters include real-time current, active power and reactive power; A processing module, configured to calculate a power factor of a current cycle based on the active power and the reactive power; Based on the real-time parameters and the power factor, determine whether the electric energy meter is in a latent state in the current cycle; the latent state indicates that the real-time current in the current cycle is a fault current; if the electric energy meter is in a latent state in the current cycle, the metering current of the electric energy meter in the current cycle is set to zero.

7. The device for processing fault current of electric energy meter according to claim 6, characterized in that: The processing module is specifically used to determine whether the current cycle of the electric energy meter is in a latent state if the active power is less than the active threshold, the reactive power is less than the reactive threshold, and the power factor is less than the power factor threshold; if the active power is less than the active threshold, the reactive power is less than the reactive threshold, or the power factor is less than the power factor threshold, then determine whether the current cycle of the electric energy meter is in a latent state based on the real-time current.

8. The device for processing fault current of electric energy meter according to claim 6, characterized in that: The processing module is specifically used to perform Fourier transform on the real-time current of the current cycle to obtain the effective value of the fundamental current and each harmonic current of the current cycle; based on the effective value of the fundamental current and each harmonic current, calculate the effective value of the total current of the current cycle; If the effective value of the fundamental current is zero and the effective value of the total current is not zero, it is determined that the electric energy meter is in a latent state in the current cycle.

9. The device for processing fault current of electric energy meter according to claim 8, characterized in that: The processing module is specifically used to determine that the electric energy meter is not in a latent state in the current cycle if the effective value of the fundamental current is greater than zero.

10. An electric energy meter, characterized in that: The electric energy meter includes an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor is used to call and run the computer program stored in the memory to perform the steps of the method as described in any one of claims 1 to 5.

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