Time-frequency magnitude sending device and method suitable for low-voltage power line carrier communication

Abstract

The invention discloses a time-frequency magnitude sending device suitable for low-voltage power line carrier communication, which avoids an HPLC (High Performance Liquid Chromatography) communication channel and selects a low frequency band for communication, the frequency band range is 200kHz-700kHz, the noise and channel attenuation of a power line at the frequency band are relatively small, and the time-frequency magnitude sending device has the characteristic of long signal transmission distance. The time-frequency magnitude signal sent by the device can cover time-consuming equipment of the whole transformer area, and a set of efficient and universal solution is provided for establishing a time-frequency magnitude transmission system for the state grid.

Description

Technical Field

[0001] The present invention relates to the technical field of power line carrier communication, and in particular to a time-frequency quantity sending device and method suitable for low-voltage power line carrier communication. Background Art

[0002] State Grid Corporation of China has built a time-frequency quantity transfer system of "national time-frequency reference - the highest time-frequency standard of State Grid - the highest time-frequency standard at provincial level / professional level - power business application", combined with the application requirements of low power consumption, low cost and miniaturization; at present, the low-voltage power line carrier communication technology is mainly HPLC, which is used for the aggregation, transmission and interaction of low-voltage power user electricity consumption information, and has a large bandwidth and high transmission rate, but has problems of large attenuation and inability to transmit over long distances.

[0003] Existing devices are difficult to meet the requirements of a device for transmitting time-frequency quantity information over medium and long distances in low-voltage power lines, so as to realize the coverage of the time-frequency quantity transmission range in low-voltage power consumption areas and ensure the accurate synchronization of time and frequency at all time-using nodes in the area. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a time-frequency quantity sending device suitable for low-voltage power line carrier communication, which can solve the problems of high-precision and low-cost time and frequency transmission and synchronization of cluster time-using devices, and takes into account the practicality and large-scale application requirements.

[0005] The time-frequency quantity sending device suitable for low-voltage power line carrier communication according to the first aspect embodiment of the present invention is characterized by comprising:

[0006] a digital signal processing module, a digital-to-analog conversion module, a sending channel analog signal processing module, a data storage module and a data interaction module, wherein;

[0007] The host computer interacts with the digital signal processing module through the data interaction module to determine the sending signal frequency and bandwidth. The digital signal processing module generates a digital signal to be sent according to the received information, converts it into an analog signal through the digital-to-analog conversion module, and the analog signal is subjected to low-pass filtering through the channel analog signal processing module to eliminate out-of-band harmonic interference, and then is subjected to power amplification and signal coupling through the channel analog signal processing module to feed the voltage signal into the low-voltage power line.

[0008] The time-frequency quantity value transmitting device applicable to low-voltage power line carrier communication according to the embodiments of the present invention has at least the following beneficial effects: aiming at the problem that the existing low-voltage power line carrier communication equipment does not meet the requirements of time-frequency quantity value transmission, a time-frequency quantity value transmitting device applicable to low-voltage power line carrier communication is provided. The transmission signal frequency band is within 0.1 - 0.7 MHz, which can avoid mutual influence with HPLC.

[0009] According to some embodiments of the present invention, for the digital signal processing module, an FPGA chip is selected, which integrates an ARM core internally, supports a large-capacity DDR storage unit, and has a main working clock of 20 MHz.

[0010] According to some embodiments of the present invention, the digital-to-analog conversion module is used to convert digital signals into analog signals. The sampling frequency is 20 MHz, the output accuracy is not less than 10 bit, and the output voltage range is 0 V - 3.3 V.

[0011] According to some embodiments of the present invention, the transmitting channel analog signal processing module performs low-pass filtering, with a passband cut-off frequency of 200 KHz and a stopband gain of -40 dB; the PA transmitting gain is 26 dB, and the feeder network power is 24 W; the transmitting impedance is not greater than 5 Ω.

[0012] According to some embodiments of the present invention, the data storage module can perform automatic data acquisition and storage, and supports large-capacity data storage of 1 GB or more.

[0013] According to some embodiments of the present invention, the data interaction module has an Ethernet interface, and based on the Ethernet interface, it interacts with the upper computer and the lower computer for system parameters and data.

[0014] The time-frequency quantity value transmitting method for low-voltage power line carrier communication according to the second aspect embodiment of the present invention is characterized by including:

[0015] Obtain the transmission signal frequency and bandwidth; generate a digital signal to be transmitted according to the signal frequency and bandwidth, convert the digital signal into an analog signal, then perform low-pass filtering through the channel analog signal processing module to eliminate out-of-band harmonic interference, and then perform power amplification and signal coupling to feed the voltage signal into the low-voltage power line.

[0016] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0018] Figure 1 The structural block diagram of the time-frequency quantity transmitting device applicable to low-voltage power line carrier communication according to an embodiment of the present invention;

[0019] Figure 2 is Figure 1 The hardware design block diagram of the time-frequency quantity transmitting device applicable to low-voltage power line carrier communication shown;

[0020] Figure 3 The front and back two-dimensional views of the time-frequency quantity transmission signal board of the time-frequency quantity transmitting device applicable to low-voltage power line carrier communication provided by an embodiment of the present invention;

[0021] Figure 4 The time-frequency diagram of the time-frequency quantity transmission signal provided by an embodiment of the present invention. Specific embodiments

[0022] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0023] In the description of the present invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for facilitating the description of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0024] In the description of the present invention, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0025] In the description of the present invention, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0026] Embodiment 1

[0027] The low-voltage power line carrier communication technology is mainly HPLC, which is used for the aggregation, transmission, and interaction of electricity consumption information of low-voltage power users. It has a large bandwidth and a high transmission rate, but there are problems such as large attenuation and inability to transmit over long distances. The HPLC communication frequency band is 0.7 - 12 MHz. To avoid mutual influence with HPLC, a time-frequency quantity value sending device with a communication frequency band within 0.1 - 0.7 MHz is required.

[0028] As Figure 1 shown, an embodiment of the present invention provides a time-frequency quantity value sending device applicable to low-voltage power line carrier communication.

[0029] It includes a digital signal processing module, a digital-to-analog conversion module, a sending channel analog signal processing module, a data storage module, and a data interaction module.

[0030] The host computer interacts with the FPGA digital signal processing module through the data interaction module to determine the sending signal frequency and bandwidth. The digital signal processing module generates a digital signal to be sent according to the received information, converts it into an analog signal through the digital-to-analog conversion module, and the analog signal is low-pass filtered by the channel analog signal processing module to eliminate out-of-band harmonic interference, and then the voltage signal is fed into the low-voltage power line through power amplification and signal coupling by the channel analog signal processing module.

[0031] The above time-frequency quantity value sending device applicable to low-voltage power line carrier communication is mainly composed of an FPGA core board, a DA conversion module, a low-pass filter module, a power amplification module, a signal coupling module, a power supply module, a USB conversion module, a Flash storage module, an Ethernet interaction module, a JTAG debugging module, a clock circuit module, and a zero-crossing circuit module, which realizes the modulation generation and signal sending of time-frequency quantity value signals. The host computer completes information interaction with the FPGA core board through the Ethernet interaction module to determine the sending signal frequency and bandwidth. The FPGA core board generates a digital signal to be sent according to the received information, converts it into an analog signal through the DA conversion module, the analog signal is low-pass filtered to eliminate out-of-band harmonic interference, and then the voltage signal is fed into the low-voltage power line through the power amplification and signal coupling module to complete the sending of time-frequency quantity value signals.

[0032] Furthermore, for the digital signal processing module, an FPGA chip is selected, which integrates an ARM hard core inside and supports a large-capacity DDR storage unit to realize high-speed digital signal processing functions, including data acquisition, signal generation, energy detection, etc. The main system working clock is 20 MHz, which is consistent with the ADC acquisition frequency.

[0033] Furthermore, the digital-to-analog conversion module realizes the function of converting digital signals into analog signals, with a sampling frequency of 20MHz, an output accuracy of not less than 10bit, and an output voltage range of 0V to 3.3V.

[0034] Furthermore, the sending channel analog signal processing module can be divided into a low-pass filter element, a power amplification element and a signal coupling element:

[0035] The low-pass filter element completes the out-of-band signal suppression function sent by the DAC, with a passband range of 0KHz to 700KHz and an out-of-band attenuation of -40dB.

[0036] The power amplifier component realizes the lossless power amplification function of analog signals. Its 5-ohm load signal transmission power is not less than 20W, and the gain in the PA linear amplification range is 26-27dB.

[0037] The signal coupling element realizes the coupling feeding network of the time-frequency value signal of 200kHz~700kHz, and adopts a low-frequency coupling transformer with a turns ratio of 1:1 and a safety capacitor.

[0038] Furthermore, the device also includes a power supply module, which includes an AC-DC module, a DC-DC module and an LDO module.

[0039] The AC-DC module provides 12V working power for the transmitting device, the DC-DC module provides 5V, 3.3V, 1.8V and 1.0V working power for the transmitting device, and the LDO module provides 1.8V analog power for the digital-to-analog conversion module and the FPGA core board.

[0040] Furthermore, the USB conversion module realizes USB-UART function conversion for system debugging, and the UART is led out by the ARM hard core.

[0041] Furthermore, the Flash storage module is used to store FPGA configuration files and hard-core program files.

[0042] Furthermore, the Ethernet interaction module realizes 1000 / 100 / 10Mbps adaptive Ethernet communication for data interaction with the host computer.

[0043] Furthermore, the JTAG debugging module is used for serial port communication to implement the FPGA parameter configuration function.

[0044] Furthermore, the clock circuit module provides a 20 MHz clock frequency for time-frequency value signal modulation generation.

[0045] Furthermore, the zero-crossing circuit module realizes the collection of the AC 220V zero-crossing signal, and the FPGA core board uses the zero-crossing characteristics of the voltage between different stations to complete the identification of adjacent stations.

[0046] As Figure 3 shown, another embodiment of the present invention provides a front and back two-dimensional view of the main board of a time-frequency magnitude signal transmitting device applicable to low-voltage power line carrier communication. Each functional module is arranged on the same PCB board, with a relatively small size, and the length and width are 120 mm and 70 mm respectively.

[0047] As Figure 4 shown, the time-frequency diagram of the voltage signal fed into the power line by the time-frequency magnitude signal transmitting device.

[0048] Embodiment 2:

[0049] Based on the time-frequency magnitude transmitting device applicable to low-voltage power line carrier communication provided in the above Embodiment 1, another embodiment of the present application provides a method applied to the above embodiment, which specifically includes:

[0050] Obtain the transmission signal frequency and bandwidth; generate a digital signal to be transmitted according to the signal frequency and bandwidth, convert the digital signal into an analog signal, and then perform low-pass filtering through the channel analog signal processing module to eliminate out-of-band harmonic interference, and then perform power amplification and signal coupling to feed the voltage signal into the low-voltage power line.

[0051] Based on the method implemented by the above device, it is possible to avoid selecting a low-frequency band for communication in the HPLC communication channel. The frequency band range is 200 kHz to 700 kHz. The power line noise and channel attenuation in this frequency band are relatively small, and it has the characteristic of a long signal transmission distance, providing a set of efficient and universal solutions for the national power grid to establish a time-frequency magnitude transfer system.

[0052] The device embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, that is, they may be located in one place, or they may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0053] Those of ordinary skill in the art will understand that all or some of the steps and systems disclosed in the above methods can be implemented as software, firmware, hardware, and their appropriate combinations. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cartridges, tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery medium.

[0054] The above is a specific description of the preferred embodiments of the present application, but the present application is not limited to the above embodiments. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present application, and these equivalent deformations or substitutions are all included within the scope defined by the claims of the present application.

Claims

1. A time-frequency value transmitting device suitable for low-voltage power line carrier communication, characterized in that: include: Digital signal processing module, digital analog conversion module, transmission channel analog signal processing module, data storage module and data interaction module, wherein; The host computer interacts with the digital signal processing module through the data interaction module to determine the frequency and bandwidth of the transmitted signal. The digital signal processing module generates a digital signal to be transmitted according to the received information, and converts it into an analog signal through the digital-to-analog conversion module. The analog signal is low-pass filtered through the channel analog signal processing module to eliminate out-of-band harmonic interference, and then power amplification and signal coupling are performed through the channel analog signal processing module to feed the voltage signal into the low-voltage power line.

2. The device according to claim 1, characterized in that The digital signal processing module uses an FPGA chip, integrates an ARM hard core, supports a large-capacity DDR storage unit, and has a working main clock of 20MHz.

3. The device according to claim 1, characterized in that The digital-to-analog conversion module is used to convert digital signals into analog signals, with a sampling frequency of 20 MHz, an output accuracy of not less than 10 bits, and an output voltage range of 0V to 3.3V.

4. The device according to claim 1, characterized in that The sending channel analog signal processing module performs low-pass filtering, with a passband cutoff frequency of 200KHz and a stopband gain of -40dB; the PA sending gain is 26dB, and the feeding power is 24W; the sending impedance is no more than 5Ω.

5. The device according to claim 1, characterized in that The data storage module can perform automatic data acquisition and storage, and supports large-capacity data storage of 1GB and above.

6. The device according to claim 1, characterized in that The data interaction module has an Ethernet interface, and exchanges system parameters and data with the upper computer and the lower computer based on the Ethernet interface.

7. A method for transmitting time-frequency value for low-voltage power line carrier communication, applied to the time-frequency value transmitting device for low-voltage power line carrier communication as claimed in any one of claims 1 to 6, characterized in that: include: Obtain the transmission signal frequency and bandwidth; generate a digital signal to be transmitted according to the signal frequency and bandwidth, convert the digital signal into an analog signal, and then perform low-pass filtering through the channel analog signal processing module to eliminate out-of-band harmonic interference, and then perform power amplification and signal coupling to feed the voltage signal into the low-voltage power line.

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