Wireless phase voltammeter

Abstract

The utility model discloses a wireless phase voltammeter, which belongs to a phase voltammeter and comprises a measuring interface board used for respectively receiving current signals and voltage signals. The measurement interface board is also respectively connected to a current measurement signal processing circuit and a voltage measurement signal processing circuit, the current measurement signal processing circuit and the voltage measurement signal processing circuit are respectively connected to respective capacitance filter circuits, and the capacitance filter circuits are connected to an additive operation circuit; the additive operation circuit is connected to the single-chip microcomputer through the frequency acquisition circuit. The single-chip microcomputer is connected to the wireless communication module. The single-chip microcomputer is used for transmitting the phase difference between the current signal and the voltage signal to the upper computer through the wireless communication module. The wireless communication module is integrated in the phase voltammeter, so that the meter can perform networking measurement and can support simultaneous measurement of multiple groups of instruments on site, the measurement efficiency is improved, and the phase difference of each signal can be obtained by calling the phase detection circuit through the single-chip microcomputer so as to improve the measurement precision.

Description

Technical Field

[0001] The utility model relates to a phase volt-ampere meter, and more specifically, mainly relates to a wireless phase volt-ampere meter. Background Art

[0002] The phase volt-ammeter is a high-precision, low-cost, handheld, dual-channel input instrument designed specifically for on-site voltage, current, and phase measurement. This meter can conveniently measure the phase between UU, II, and UI, identify inductive and capacitive circuits and the phase sequence of three-phase voltages, detect transformer wiring groups, test secondary circuits and busbar differential protection systems, read the phase relationship between differential protection CT groups, and verify correct meter wiring. However, similar phase volt-ammeters currently available on the market have limited accuracy and are generally limited to stand-alone operation, not online use. This hinders on-site voltage and current measurement, necessitating further research and improvement of similar phase volt-ammeter structures. Utility Model Content

[0003] One of the purposes of the present invention is to provide a wireless phase volt-ammeter to address the above-mentioned shortcomings, in order to solve the technical problems of similar phase volt-ammeters in the prior art, such as limited accuracy and inability to operate online.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The utility model provides a wireless phase volt-ammeter, which includes a measurement interface board, which is used to receive current signals and voltage signals respectively; the measurement interface board is also connected to a current measurement signal processing circuit and a voltage measurement signal processing circuit respectively, and the current measurement signal processing circuit and the voltage measurement signal processing circuit are respectively connected to their own capacitor filter circuits, and the capacitor filter circuits are both connected to an addition circuit; the addition circuit is connected to a single-chip microcomputer through a frequency acquisition circuit, and the single-chip microcomputer is connected to a wireless communication module; the single-chip microcomputer is used to transmit the phase difference between the current signal and the voltage signal to a host computer through the wireless communication module; the phase difference between the current signal and the voltage signal is, after filtering by the capacitor filter circuit, the current signal and the voltage signal are collected by the frequency acquisition circuit, and after amplification again, an accurate periodic signal is obtained, which is then transmitted to the single-chip microcomputer and obtained after the single-chip microcomputer processes and compares the time difference of each signal.

[0006] As a preferred further technical solution: the addition circuit is further connected to the single chip microcomputer through a phase detection circuit, and the phase detection circuit is used by the single chip microcomputer to call and compare the time difference between the current signal and the voltage signal, and then obtain the phase difference.

[0007] A further technical solution is: the measurement interface board is used to sense the current signal through the AC transformer current clamp and transmit it to the current measurement signal processing circuit, and proportionally reduce the measured voltage signal through resistor voltage division and then transmit it to the voltage measurement signal processing circuit.

[0008] A further technical solution is: the single chip microcomputer is further connected to a liquid crystal display module, so as to output the phase difference between the current signal and the voltage signal to the liquid crystal display module for display.

[0009] A further technical solution is: the single chip microcomputer is also connected to at least one data transmission module, and the data transmission module includes a 4G communication module, a Bluetooth communication module, an SD card reading module, a USB communication module and an RJ-45 network cable interface module.

[0010] Compared with the existing technology, one of the beneficial effects of the present invention is that by integrating a wireless communication module into the phase voltammeter, the instrument can perform networked measurements and support simultaneous measurements of multiple groups of instruments on site, which not only improves the measurement efficiency, but also can obtain the phase difference of each signal by calling the phase detection circuit through the single-chip microcomputer to improve the measurement accuracy. At the same time, the wireless phase voltammeter circuit module provided by the present invention is simple, suitable for industrial production, and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic structural diagram for illustrating an embodiment of the utility model. DETAILED DESCRIPTION

[0012] The present invention will be further described below in conjunction with the accompanying drawings.

[0013] refer to Figure 1 As shown, one embodiment of the present invention is a wireless phase voltammeter, which includes a measurement interface board, which is used to receive current signals and voltage signals respectively; as shown in the figure, the aforementioned measurement interface board is also connected to the current measurement signal processing circuit and the voltage measurement signal processing circuit respectively, and the current measurement signal processing circuit and the voltage measurement signal processing circuit are respectively connected to their respective capacitor filter circuits, and the capacitor filter circuits are both connected to the addition circuit; at the same time, the addition circuit is connected to the single-chip microcomputer through the frequency acquisition circuit, and the single-chip microcomputer is connected to the wireless communication module; the single-chip microcomputer is used to transmit the phase difference between the current signal and the voltage signal to the host computer through the wireless communication module; the phase difference between the current signal and the voltage signal referred to here is, after filtering by the capacitor filter circuit, the current signal and the voltage signal are collected by the frequency acquisition circuit, and the accurate periodic signal is obtained after amplification again, and then transmitted to the single-chip microcomputer, and the single-chip microcomputer processes and compares the time difference of each signal.

[0014] Furthermore, the addition circuit is connected to a single-chip microcomputer via a phase detection circuit. This phase detection circuit is called by the single-chip microcomputer to compare the time difference between the current signal and the voltage signal to obtain the phase difference. The measurement interface board senses the current signal via an AC transformer current clamp and transmits it to the current measurement signal processing circuit. The measured voltage signal is then proportionally reduced by a resistor divider before being transmitted to the voltage measurement signal processing circuit.

[0015] Refer again Figure 1 As shown, in the structure shown in the above embodiment, the single-chip microcomputer is also connected to a liquid crystal display module for outputting the phase difference between the current signal and the voltage signal to the liquid crystal display module for display. The single-chip microcomputer is also connected to at least one data transmission module, which includes a 4G communication module, a Bluetooth communication module, an SD card reader module, a USB communication module, and an RJ-45 network cable interface module.

[0016] In this embodiment, by integrating a wireless communication module into the phase voltammeter, the instrument can perform networked measurements and support simultaneous measurements of multiple groups of instruments on site. This not only improves the measurement efficiency, but also allows the microcontroller to call the phase detection circuit to obtain the phase difference of each signal to improve the measurement accuracy.

[0017] Based on the above embodiments, the principle of the wireless phase volt-ampere meter of the present invention is as follows:

[0018] Measurement Interface Board: The measured current is induced by the AC transformer current clamp, generating a current signal. This signal is then input to the measurement mainboard via the current interface of the measurement interface board for signal processing. The measured voltage signal is then input to the measurement interface board via the input voltage interface. The interface board then uses resistor divider to scale the measured voltage signal 500 times, before inputting it to the measurement mainboard for signal processing. The 1M input impedance of the voltage input interface effectively prevents high external current from entering the instrument, potentially posing a safety hazard.

[0019] Current measurement signal processing circuit: The current clamp inputs an AC current signal. Based on Ohm's law, current I is proportional to voltage U. A resistor converts the input current signal into a voltage signal. A high-precision, low-drift operational amplifier chip and multiple analog switches form a high-precision, multi-speed, inverse-proportional operational amplifier circuit to amplify the AC current measurement signal.

[0020] The capacitor filters out the DC interference signal in the measured signal, and through the op amp adding circuit, the measured signal is raised and collected by the high-speed 16-bit ADC acquisition chip and transmitted to the microcontroller.

[0021] Voltage measurement signal processing circuit: (basically the same, except for the front-end current-to-voltage conversion circuit)

[0022] Frequency acquisition circuit: The collected current and voltage signals are amplified by the front-end signal and then amplified and compared again by the waveform signal processing circuit to obtain an accurate waveform period signal. By comparing the time difference of each signal, the accurate phase difference can be obtained.

[0023] Wireless communication: Utilizes LoRa wireless communication technology. Developed by Semtech, LoRa is a low-power local area network wireless standard. It is a long-range radio. Its greatest feature is that it can transmit farther than other wireless methods at the same power consumption, achieving the perfect balance between low power consumption and long distance. It extends the range of traditional wireless RF communication by 3-5 times. It features long-distance communication, low power consumption, strong anti-interference capabilities, and easy deployment and maintenance. Multiple sets of equipment can be used on-site to conduct separate network measurements using different frequency bands.

[0024] Based on the above principles, the signal flow in the wireless phase volt-ampere meter is as follows:

[0025] The voltage signal is collected by the voltage test line, and the current signal is collected by the current transformer, and enters the instrument through the measurement interface board.

[0026] Each voltage and current signal will pass through a separate amplifier circuit, then through a filtering circuit, and be converted into a digital signal by a high-precision analog-to-digital converter (ADC) and transmitted to the microcontroller for processing.

[0027] The filtered voltage and current signals will also pass through the frequency acquisition circuit. The collected signals will be amplified again to obtain accurate periodic signals. After being transmitted to the microcontroller, the microcontroller program will process and compare the time differences of each signal to obtain the accurate phase difference.

[0028] Data processed by the microcontroller is displayed on the LCD screen and transmitted to the host computer via LoRa wireless communication technology. The host computer then displays the data from the two measurement points, facilitating comparative analysis of voltage and current information at different locations. Multiple instrument hosts can be networked to test data from test points within the test range. The host computer can then view the test data from each slave device, facilitating comparison of test data at each data point.

[0029] The instrument has built-in 4G module and Bluetooth module, and the test data can be read by connecting the instrument to the mobile phone.

[0030] The instrument has a serial-to-USB conversion circuit and an isolation circuit. During testing, it can be connected to the host computer software to view real-time test data, or connected to a USB flash drive to read instrument stored data.

[0031] The wireless phase volt-ammeter in this utility model is suitable for synchronously measuring parameters such as the true effective value of three-phase AC voltage and current, phase between voltages, phase between voltages and currents, frequency, phase sequence, active power, reactive power, apparent power, power factor, and total power at different measuring points in the secondary circuit of a substation, which facilitates users to measure and compare multiple measuring points simultaneously. The utility model is suitable for substations, power departments, petrochemical industry, metallurgy, railways, meteorology, industrial and mining enterprises, monitoring stations, scientific research institutions, field electrical work, etc.

[0032] When a single instrument terminal is used, it can be used as a three-phase phase voltammeter to measure line parameters such as current, voltage, phase, power, etc., and display the measurement parameters and vector diagram on the same screen.

[0033] When multiple instrument terminals are used simultaneously, three-phase electrical parameters and vector diagrams can be measured simultaneously at multiple measurement points. Data and vector diagrams from any two instruments can be compared on the same screen within the configured host computer. Up to four devices can be networked for measurement. This eliminates the need for temporary cables between different measurement points at the test site, solving the problem of difficult measurements at different points in the substation and ensuring simple and safe operation.

[0034] The instrument features a 5.6-inch true-color LCD screen with a graphical menu interface and vectorgraph indicators for easy viewing. It offers automatic measurement, data storage, data review, automatic shutdown, Bluetooth communication, and USB data upload. The mobile app allows users to view measurement parameters, read stored data, and export it to Excel spreadsheets. The instrument utilizes a high-precision measurement chip for accurate measurement data. The integrated current clamp handle and pointed sensor design facilitate operation, making it suitable for use in densely packed wiring environments. Simple and convenient operation provides a safe, accurate, and convenient smart meter for power inspectors.

[0035] When performing networked measurements, simply set the channel and device type and the instrument will automatically connect upon power on. 110 frequency bands are available for selection, allowing multiple instrument groups to perform simultaneous measurements on-site without interfering with each other. Using LoRa wireless communication technology, the instrument achieves long transmission distances.

[0036] The current measurement signal processing circuit, voltage measurement signal processing circuit, capacitor filter circuit, addition operation circuit, phase detection circuit, frequency acquisition circuit and measurement interface board mentioned in the present invention can all be transplanted using similar circuits of existing phase voltammeters. It is estimated that the structure and principle of the aforementioned circuits will not be described in detail, and the improvement purpose of the present invention is not to this end.

[0037] In addition to the above, it should be noted that references to "one embodiment," "another embodiment," "an embodiment," and the like in this specification refer to specific features, structures, or characteristics described in conjunction with that embodiment as being included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in conjunction with any embodiment, it is intended that such feature, structure, or characteristic, when implemented in conjunction with other embodiments, also fall within the scope of the present invention.

[0038] Although the present invention has been described herein with reference to a number of illustrative embodiments thereof, it will be understood that numerous other modifications and implementations may be devised by those skilled in the art that fall within the scope and spirit of the principles disclosed herein. More specifically, within the scope of the present disclosure, the drawings, and the claims, numerous variations and modifications may be made to the components and / or arrangement of the subject combination arrangement. In addition to variations and modifications to the components and / or arrangement, other uses will also be apparent to those skilled in the art.

Claims

1. A wireless phase volt-ampere meter, characterized by: It includes a measurement interface board, which is used to receive current signals and voltage signals respectively; The measurement interface board is further connected to a current measurement signal processing circuit and a voltage measurement signal processing circuit respectively, and the current measurement signal processing circuit and the voltage measurement signal processing circuit are respectively connected to respective capacitor filter circuits, and the capacitor filter circuits are both connected to an addition operation circuit; The addition circuit is connected to the single-chip microcomputer through the frequency acquisition circuit, and the single-chip microcomputer is connected to the wireless communication module; the single-chip microcomputer is used to transmit the phase difference between the current signal and the voltage signal to the host computer through the wireless communication module; The phase difference between the current signal and the voltage signal is obtained by filtering by the capacitor filter circuit, collecting the current signal and the voltage signal by the frequency acquisition circuit, and amplifying them again to obtain an accurate periodic signal, which is then transmitted to the single-chip microcomputer and processed by the single-chip microcomputer to compare the time difference of each signal.

2. The wireless phase volt-ampere meter according to claim 1, characterized in that: The addition circuit is further connected to the single chip microcomputer via a phase detection circuit, and the phase detection circuit is used for the single chip microcomputer to call and compare the time difference between the current signal and the voltage signal, thereby obtaining the phase difference.

3. The wireless phase volt-ampere meter according to claim 1, characterized in that: The measurement interface board is used to sense the current signal through the AC transformer current clamp and transmit it to the current measurement signal processing circuit, and to proportionally reduce the measured voltage signal through resistor voltage division and then transmit it to the voltage measurement signal processing circuit.

4. The wireless phase volt-ampere meter according to claim 1, characterized in that: The single chip microcomputer is further connected to a liquid crystal display module for outputting the phase difference between the current signal and the voltage signal to the liquid crystal display module for display.

5. The wireless phase volt-ampere meter according to claim 1, characterized in that: The single chip microcomputer is also connected to at least one data transmission module, which includes a 4G communication module, a Bluetooth communication module, an SD card reading module, a USB communication module and an RJ-45 network cable interface module.

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