Method for automatically correcting phase sequence of a three-phase AC meter

Abstract

The application discloses a kind of three-phase AC meter automatic correction phase sequence method, including steps S1: communication module receives the correction command sent by user, to make that electric meter enters correction mode, and communication module receives the current power grid reference data provided by user;Step S2: electric meter uses the waveform data of voltage and current obtained by metering module, and the waveform data of voltage and current obtained by current power grid reference data is analyzed by processing module, to obtain estimated phase sequence scheme and send estimated phase sequence scheme to user by communication module, to end correction process after correct scheme is selected by user.The three-phase AC meter automatic correction phase sequence method disclosed in the application enables three-phase AC meter to be normally used when installed incorrectly, solving the problem of electric meter being unable to use caused by installation error.

Description

Technical Field

[0001] This invention belongs to the field of power metering technology, specifically relating to a method for automatically correcting the phase sequence of a three-phase AC meter. Background Technology

[0002] The installation of existing three-phase AC meters typically requires the three phases to be connected to the meter in the correct sequence for accurate measurement. However, installation errors often occur during on-site installation, especially with current transformers in inductive meters. When incorrectly installed, the existing meter often fails to function properly, requiring on-site reinstallation, which is time-consuming and labor-intensive. This method, however, can correct the phase sequence of the meter when it is not installed correctly, saving the trouble of reinstallation.

[0003] Therefore, further improvements will be made to address the aforementioned issues. Summary of the Invention

[0004] The main objective of this invention is to provide a method for automatically correcting the phase sequence of a three-phase AC meter, enabling the meter to function normally even when installed incorrectly. This solves the problem of meters becoming unusable due to installation errors, especially since the current transformers in mutual inductance meters are very prone to incorrect installation, resulting in incorrect or reversed transformer configurations. This invention solves this problem, thereby saving the associated losses from reinstallation.

[0005] To achieve the above objectives, the present invention provides a method for automatically correcting the phase sequence of a three-phase AC meter, comprising the following steps:

[0006] Step S1: The communication module receives the calibration command sent by the user, so that the meter enters calibration mode, and the communication module receives the current power grid reference data provided by the user.

[0007] Step S2: The meter uses the metering module to acquire voltage and current waveform data, and the processing module analyzes the acquired voltage and current waveform data through the current power grid reference data to obtain the estimated phase sequence scheme and sends the estimated phase sequence scheme to the user through the communication module. The calibration process ends after the user selects the correct scheme.

[0008] As a further preferred technical solution to the above technical solution, in step S2:

[0009] First, the voltage phase sequence is determined by the voltage waveform phase. Then, the current phase sequence is determined based on the power grid reference data provided by the user. The matching result is saved and the user is informed. If there are multiple possible results, the user can switch the scheme to select the correct phase sequence correction result, so as to achieve the purpose of making the meter work normally without reinstalling the meter.

[0010] As a further preferred technical solution to the above technical solution, in the processing module analysis of step S2, if the current meter is a mutual inductance meter, it is also necessary to determine the forward and reverse directions of the mutual inductor.

[0011] As a further preferred technical solution of the above technical solution, in step S2, the phase difference of the three-phase grid voltage is 120°, that is, L2 lags behind L1 by 120° and L3 lags behind L2 by 120°.

[0012] The voltage waveforms acquired by the metering module are analyzed to obtain the rising and falling trends and the sequence of zero points, thereby deriving the corresponding voltage phase sequence. Using the current power grid reference data provided by the user, including the voltage, current, active power, and reactive power values ​​of each phase, or the angle between the voltage and current of each phase, the current waveforms acquired by the metering module are analyzed to obtain the current phase of the three-phase current. This is compared with the current power grid reference data to estimate the corresponding wiring scheme and provide it to the customer. (If the current voltage is unbalanced, voltage phase correction can also be performed using the correct current power grid reference data provided by the user, with the correction principle being the same as above.)

[0013] As a further preferred technical solution to the above technical solution, (as can be seen from the phase diagram) in step S2, the active power and reactive power values ​​of each phase under the current connection of the meter are obtained, that is, the angle between voltage and current is obtained. After calculating the three-phase angle, the current phase of all voltages and currents is obtained according to the voltage phase sequence result. The correct voltage and current phases of the current power grid are extracted and matched using the current power grid reference data provided by the user. At the same time, the mutual inductance meter analyzes whether the mutual inductors are reversed. After the matching is completed, all possible results are output.

[0014] Compared with existing technologies, the beneficial effects of this method are:

[0015] 1. Achieve automatic phase sequence correction without adding external devices.

[0016] Second, reduce the losses and troubles caused by incorrect installation of three-phase AC meters. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the operation of a three-phase AC meter, which is a method for automatically correcting the phase sequence of the present invention.

[0018] Figure 2 This is a flowchart of a method for automatically correcting the phase sequence of a three-phase AC meter according to the present invention.

[0019] Figure 3 This is a three-phase AC voltage waveform diagram of a method for automatically correcting the phase sequence of a three-phase AC meter according to the present invention.

[0020] Figure 4This invention relates to a power phase diagram of a method for automatically correcting the phase sequence of a three-phase AC meter. Detailed Implementation

[0021] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0022] In the preferred embodiments of the present invention, those skilled in the art should note that the electricity meters and the like involved in the present invention can be considered as prior art.

[0023] Preferred embodiment.

[0024] like Figure 1-4 As shown, this invention discloses a method for automatically correcting the phase sequence of a three-phase AC meter, comprising the following steps:

[0025] Step S1: The communication module receives the calibration command sent by the user, so that the meter enters calibration mode, and the communication module receives the current power grid reference data provided by the user.

[0026] Step S2: The meter uses the metering module to acquire voltage and current waveform data, and the processing module analyzes the acquired voltage and current waveform data through the current power grid reference data to obtain the estimated phase sequence scheme and sends the estimated phase sequence scheme to the user through the communication module. The calibration process ends after the user selects the correct scheme.

[0027] Specifically, in step S2:

[0028] First, the voltage phase sequence is determined by the voltage waveform phase. Then, the current phase sequence is determined based on the power grid reference data provided by the user. The matching result is saved and the user is informed. If there are multiple possible results, the user can switch the scheme to select the correct phase sequence correction result, so as to achieve the purpose of making the meter work normally without reinstalling the meter.

[0029] More specifically, in the processing module analysis of step S2, if the current meter is a mutual inductance meter, it is also necessary to determine the forward and reverse orientation of the mutual inductor.

[0030] Furthermore, in step S2, the phase difference of the three-phase grid voltage is 120°, that is, L2 lags behind L1 by 120°, and L3 lags behind L2 by 120°.

[0031] The voltage waveforms acquired by the metering module are analyzed to obtain the rising and falling trends and the sequence of zero points, thereby deriving the corresponding voltage phase sequence. Using the current power grid reference data provided by the user, including the voltage, current, active power, and reactive power values ​​of each phase, or the angle between the voltage and current of each phase, the current waveforms acquired by the metering module are analyzed to obtain the current phase of the three-phase current. This is compared with the current power grid reference data to estimate the corresponding wiring scheme and provide it to the customer. (If the current voltage is unbalanced, voltage phase correction can also be performed using the correct current power grid reference data provided by the user, with the correction principle being the same as above.)

[0032] Depend on Figure 3 It is clear that the phase sequence of a three-phase voltage waveform can be determined by its changing trend and the order in which it crosses zero, and the corresponding results can be obtained to correct the voltage phase sequence.

[0033] Furthermore, (through phase diagrams, Figure 4 As can be seen, in step S2, the active and reactive power values ​​of each phase under the current connection of the meter are obtained, that is, the angle between voltage and current is obtained. After calculating the three-phase angle, the current phase of all voltages and currents is obtained according to the voltage phase sequence result. The correct voltage and current phases of the current power grid are extracted through the current power grid reference data provided by the user and matched. At the same time, the mutual inductance meter analyzes whether the mutual inductors are reversed. After the matching is completed, all possible results are output.

[0034] It is worth mentioning that the technical features of the electricity meter and other related technologies involved in this patent application should be regarded as prior art. The specific structure, working principle, control method and spatial arrangement of these technical features can be adopted using conventional choices in the field, and should not be regarded as the inventive point of this patent. This patent will not be further elaborated in detail.

[0035] For those skilled in the art, 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. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A method for automatically correcting the phase sequence of a three-phase AC meter, characterized by, The method comprises the following steps: Step S1: the communication module receives a correction command sent by a user to make the electric meter enter a correction mode, and receives current power grid reference data provided by the user; Step S2: the electric meter uses a metering module to obtain waveform data of voltage and current, and a processing module analyzes the obtained waveform data of voltage and current through the current power grid reference data to obtain an estimated phase sequence scheme and sends the estimated phase sequence scheme to the user through the communication module, so as to end the correction process after the user selects a correct scheme; In step S2: First, the voltage phase sequence is determined through the voltage waveform phase, and then the current phase sequence is determined according to the power grid reference data provided by the user, the matching result is saved, and the user is informed, if there are multiple possible results, the user selects the correct phase sequence correction result by switching the scheme, to achieve the purpose of making the electric meter work normally without reinstalling the electric meter; In the analysis of the processing module in step S2, if the current electric meter is a mutual inductor, the mutual inductor needs to be judged in forward and reverse directions; In step S2, the phase difference of the three-phase power grid voltage is 120°, that is, L2 lags behind L1 by 120°, and L3 lags behind L2 by 120°; The voltage waveform collected by the metering module is analyzed to obtain the rising and falling trend and the order of passing through 0 point, so as to obtain the corresponding voltage phase sequence, and through the current grid reference data provided by the user, including the voltage, current, active power and reactive power values of each phase, or the included angle between each phase voltage and current, the current waveform obtained by the metering module is analyzed to obtain the current phase, and the current grid reference data is compared to estimate the corresponding wiring scheme and provide it to the customer; In step S2, the active power and reactive power values of each phase under the current wiring of the electric meter are obtained, that is, the included angle between the voltage and current is calculated, and then according to the voltage phase sequence result, the current phase of all voltages and currents is obtained, the correct voltage and current phase of the current power grid is extracted through the current power grid reference data provided by the user, and matching is performed, at the same time, the mutual inductor of the mutual inductor type electric meter is analyzed whether it is reversed, and after the matching is completed, all possible results are output.

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