High-performance digital three-phase voltage sensor

Abstract

The utility model discloses a high-performance digital three-phase voltage sensor, which relates to the technical field of electric quantity sensors, and comprises an isolation conversion module, a calculation display module, an output module and a power output module, the isolation conversion module is used for isolating and converting 220V voltage signals into 5V voltage signals and converting analog voltage signals into digital signals, and the calculation display module is used for outputting the digital signals. Digital processing is facilitated; the calculation display module and the isolation conversion module are interconnected in a serial SPI communication mode, and the calculation display module extracts a fundamental frequency signal through a filtering algorithm and calculates a voltage amplitude; according to the utility model, through the arrangement of the isolation conversion module, the calculation display module and the output module, a serial communication interface, an Ethernet communication interface and analog quantity current signals can be provided, and various communication protocols such as Modbus, IEC101, IEC104, IEC103, IEC61850GOOSE and the like can be supported; the problems that a traditional analog voltage transmitter and a traditional analog voltage sensor are insufficient in precision, high in time delay, poor in temperature stability and sensitive to external interference are effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric quantity sensors, in particular to a high-performance digital three-phase voltage sensor. Background Art

[0002] Voltage sensors are devices used to measure voltage signals. They can be analog or digital; analog sensors output a continuous signal proportional to the voltage amplitude, while digital sensors provide a digital output that can be read directly by a microprocessor or computer system.

[0003] These sensors are widely used in smart grids, power monitoring and control systems, power quality analysis, distributed power management and many other fields.

[0004] Analog voltage transmitters can only provide analog voltage or current output, and digital voltage transmitters can generally only provide serial communication interface output.

[0005] In the prior art, traditional analog voltage transmitters and sensors have problems such as insufficient accuracy, high delay, poor temperature stability and sensitivity to external interference in some applications. Therefore, a high-performance digital three-phase voltage sensor is needed. Utility Model Content

[0006] The purpose of this application is to provide a high-performance digital three-phase voltage sensor to solve the problems raised in the above background technology.

[0007] To achieve the above objectives, the present application provides the following technical solution: a high-performance digital three-phase voltage sensor, comprising:

[0008] Isolation conversion module, the isolation conversion module is used to isolate and convert the 220V voltage signal into a 5V voltage signal;

[0009] The calculation and display module is interconnected with the isolation conversion module through a serial SPI communication mode. The calculation and display module extracts the baseband signal through a filtering algorithm and calculates the voltage amplitude and the three-phase positive sequence voltage;

[0010] The output module is interconnected with the calculation and display module through a serial SPI communication mode; the output module converts and outputs the calculated positive sequence voltage signal;

[0011] The power output module provides power to the isolation conversion module, the calculation and display module and the output module.

[0012] Preferably, the isolation conversion module converts the analog voltage signal into a digital signal for digital processing.

[0013] Preferably, the calculation and display module is also used to determine external circuit abnormalities such as voltage circuit disconnection and reverse sequence.

[0014] Preferably, the output module converts the positive sequence voltage signal into serial communication, Ethernet communication digital signal output and analog current signal output.

[0015] Preferably, the analog current signal is 4-20 mA.

[0016] Preferably, the power output module outputs the alarm signal through a relay.

[0017] In summary, the technical effects and advantages of the utility model are:

[0018] In the utility model, through the setting of the isolation conversion module, the calculation display module and the output module, a serial communication interface, an Ethernet communication interface and an analog current signal can be provided, and multiple communication protocols such as Modbus, IEC101, IEC104, IEC103, IEC61850 GOOSE are supported, which effectively solves the problems of insufficient accuracy, high delay, poor temperature stability and sensitivity to external interference of traditional analog voltage transmitters and sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 is the overall structural block diagram of this embodiment;

[0021] Figure 2 is a schematic diagram of the planar structure of the calculation and display module in this embodiment;

[0022] Figure 3 Schematic diagram of the serial ports of the isolation conversion module in this embodiment. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] Example: Reference Figure 1-3A high-performance digital three-phase voltage sensor is shown, which is composed of an isolation conversion module, a calculation and display module, an output module and a power output module;

[0025] The isolation conversion module is used to isolate and convert the 220V voltage signal into a 5V voltage signal, and convert the analog voltage signal into a digital signal for digital processing;

[0026] The calculation and display module is interconnected with the isolation conversion module through serial SPI communication. The calculation and display module extracts the baseband signal through a filtering algorithm and calculates the voltage amplitude, calculates the positive sequence voltage and determines external circuit abnormalities such as voltage circuit disconnection and reverse sequence;

[0027] The output module is interconnected with the calculation and display module through serial SPI communication; the output module converts the calculated positive sequence voltage signal into serial communication, Ethernet communication digital signal output and 4-20mA analog current signal output;

[0028] The power output module provides power to the isolation conversion module, calculation display module and output module, and outputs the alarm signal through the relay.

[0029] Based on the above structure, the high-performance digital three-phase voltage sensor can provide serial communication interface, Ethernet communication interface, analog current signal, and support multiple communication protocols such as Modbus, IEC101, IEC104, IEC103, IEC61850 GOOSE, etc., effectively solving the problems of insufficient accuracy, high delay, poor temperature stability and sensitivity to external interference of traditional analog voltage transmitters and sensors.

[0030] Among them, the high-performance digital three-phase voltage sensor in this embodiment adopts a back-inserted aluminum profile chassis as a whole, the chassis size is 96mm*96mm*80mm, and the three-phase voltage of the two bus sections is connected. The voltage input range is rated at 220V, and 1.2 times the overvoltage range is considered; the digital value of the voltage measurement result is output through the RS-485 interface and the RJ-45 Ethernet interface, and the 4-20mA current signal corresponding to the two bus bars is output at the same time.

[0031] Under normal circumstances, the measured values ​​are displayed cyclically through the 6-digit digital tube. The user can view the current operating set value by pressing the button and set 3 signal indicator lights to indicate the power supply, operation and alarm signal status respectively.

[0032] The calculation and display module uses an ARM microcontroller with a main frequency of 120MHz and a serial Nor Flash memory with an extended model of W25Q256JVFIQ to store parameter settings, events and other data; an RTC clock chip with a model of RX8025T-UB is selected to provide accurate time for the device; an isolation chip with a model of ADUM1201AR and an RS-232 transceiver with a model of MAX3232EUE+T are selected to expand the RS-232 serial communication interface for connecting the device configuration software; an Ethernet physical layer PHY chip with a model of SR8201FI is selected to expand the 100Mbps electrical Ethernet interface; a 0.36-inch 6-digit common anode digital tube with a model of 3661BS is selected to display the operating status of the device.

[0033] The isolation conversion module uses the TS31140CI micro voltage transformer, which is used to isolate and convert the AC voltage signal to the ±5V range; the high-order harmonics are filtered out through a first-order RC filter circuit with a cut-off frequency of 604Hz; the data is collected by the AD7606BSTZ analog-to-digital conversion chip and sent to the calculation and display module through the SPI communication interface.

[0034] The calculation and display module calculates the voltage amplitude and phase of the six voltage channels through the full-cycle Fourier algorithm, and calculates the positive-sequence voltage of the two bus sections. It determines whether the wiring is broken or reversed by calculating whether the zero-sequence voltage and negative-sequence voltage of the two bus sections exceed the limit, and then sends the calculation results to the output module through the SPI communication interface.

[0035] The output module sends the positive sequence voltage results of the two bus sections to the output module through the SPI interface. The output module uses two AD5420AREZ chips to output the 4-20mA signal corresponding to the voltage of the two bus sections; the serial 485 interface is expanded through the RS-485 transceiver model MAX13487EESA+T, and the RJ-45 electrical Ethernet interface is expanded through the isolation transformer model HX1188NL.

[0036] The power module uses the LS05-13B05R3 power chip to provide 5V power for the entire device. The power chip has an ultra-wide voltage input range and supports AC / DC power supply, with a voltage range of 85-305VAC / 70-430VDC; and uses 2 relays with model G2RL-1A-E-CN-5VDC to output alarm signals.

[0037] In addition, the calculation and display module also provides human-machine interface functions, which are used to display the current measurement values ​​and device operating status through digital tube output and signal indicator lights; buttons are provided for switching display screens, and a configuration serial communication interface is provided for viewing and modifying device parameters.

[0038] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high performance digital three-phase voltage sensor, characterized in that: include: An isolation conversion module, wherein the isolation conversion module is used to isolate and convert a 220V voltage signal into a 5V voltage signal; A calculation and display module, wherein the calculation and display module is interconnected with the isolation conversion module via a serial SPI communication mode, and the calculation and display module extracts the baseband signal and calculates the voltage amplitude and the three-phase positive sequence voltage via a filtering algorithm; An output module, wherein the output module is interconnected with the calculation and display module via a serial SPI communication mode; the output module converts and outputs the calculated positive sequence voltage signal; A power output module provides power to the isolation conversion module, the calculation and display module, and the output module.

2. A high performance digital three-phase voltage sensor according to claim 1, characterized in that: The isolation conversion module converts the analog voltage signal into a digital signal for digital processing.

3. A high performance digital three-phase voltage sensor according to claim 1, characterized in that: The calculation and display module is also used to determine whether the voltage circuit is broken and the reverse sequence external circuit is abnormal.

4. A high performance digital three-phase voltage sensor according to claim 1, characterized in that: The output module converts the positive sequence voltage signal into serial communication, Ethernet communication digital signal output and analog current signal output.

5. A high performance digital three-phase voltage sensor according to claim 4, characterized in that: The analog current signal is 4-20mA.

6. A high performance digital three-phase voltage sensor according to claim 1, characterized in that: The power output module outputs the alarm signal through a relay.

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