Passive wireless current detection synchronization system, method, terminal and storage medium for three-phase power line

Abstract

The application provides a passive wireless current detection synchronization system and method for a three-phase power line, a terminal and a storage medium. A host sends a synchronization signal to at least three passive wireless digital current transformers. Each passive wireless digital current transformer receives the synchronization signal sent by the host, controls the passive wireless digital current transformer and other wireless digital current transformers to synchronously collect current signals according to the synchronization signal and a time delay set by the passive wireless digital current transformer, and sends a digital current signal frame formed by the collected current signals to the host. The passive wireless current detection synchronization for the three-phase power line is realized, and the problems of phase difference, harmonic analysis errors and the like caused by time delay errors of the system are solved.

Description

Technical Field

[0001] This invention relates to the technical field of detecting current in power transmission lines, and in particular to a passive wireless current detection synchronization system, method, terminal, and storage medium for three-phase power lines. Background Technology

[0002] With the gradual construction of smart grids, high-precision detection of transmission line current and acquisition of current waveforms have become pressing issues. Real-time detection of current waveform data during grid operation is the first step in all intelligent relay protection operations. Only by achieving safe and accurate measurement of line current can the intelligence of the grid be further improved. However, for 10kV, 35kV, and higher voltage transmission lines, wired power transformers are not permitted for current signal acquisition because their signal lines would introduce high-voltage electricity into the secondary system, posing a safety hazard. If the distance is close, it would inevitably lead to safety accidents such as transmission line grounding. Additionally, there are wireless current transformers on the market that use self-powered methods, but these transformers either suffer from low sampling rates due to frequency limitations of the transmission channel, or they can only be used for current acquisition of a single transmission conductor, not for simultaneous sampling of three-phase lines. Furthermore, there are also analysis errors such as phase difference and harmonics caused by system delay errors. Utility model patent CN202033401U discloses a "wireless current measuring device," which also uses a current transformer (CT) for power supply and a current transformer to collect current signals, transmitting the measurement data wirelessly to a receiving terminal. However, it neglects the synchronization relationship between the three-phase line currents, thus adding the delay errors of various components during measurement and communication to the phase of the current waveform, further leading to inaccuracies in the phase difference of the three-phase electrical data. Invention patent CN108896815A discloses an "open-type wireless current transformer converter and signal conversion method," which uses signal conversion to transmit the collected current values, a process that is complex and consumes significant power. Utility model patent CN209559965U discloses a "wireless power data acquisition device," which provides a one-to-one power data acquisition device, i.e., one wireless measurement node corresponds to one wireless data receiving device, but it cannot solve the problem of aligning multiple electrical data collection values ​​in time, i.e., the three-phase current synchronization problem. The invention patents published under application number CN104049132A, which disclose a "wireless current sensor device," and CN103903845A, which disclose a "passive wireless current transformer," also have the same problem. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a passive wireless current detection synchronization system, method, terminal and storage medium for three-phase power lines, which solves the problems of asynchronous passive wireless current detection in three-phase power lines and parameter analysis errors caused by system delay errors in the prior art.

[0004] To achieve the above and other related objectives, the present invention provides a passive wireless current detection and synchronization system for a three-phase power line. The system includes: at least three passive wireless digital current transformer sub-units; a host unit connected to the at least three matched passive wireless digital current transformer sub-units, used to send synchronization signals to the at least three matched passive wireless digital current transformer sub-units; wherein each passive wireless digital current transformer sub-unit is used to receive the synchronization signal sent by the host unit, and according to the synchronization signal and the delay time set by the passive wireless digital current transformer sub-unit, control the passive wireless digital current transformer sub-unit to synchronously collect current signals with other wireless digital current transformer sub-units, and form the collected current signals into digital current signal frames and send them to the host unit.

[0005] In one embodiment of the present invention, the method for calculating the delay time includes: obtaining the transmission time of the synchronization signal sent by the host and the response time of the passive wireless digital current transformer sub-unit in response to the synchronization signal, and determining the transmission response time difference corresponding to the synchronization signal; obtaining the delay time corresponding to the passive wireless digital current transformer sub-unit based on the fixed response time of the corresponding passive wireless digital current transformer sub-unit and the transmission and reception time difference.

[0006] In one embodiment of the present invention, the matching method between the host and each sub-unit includes: the host matching with each passive wireless digital current transformer sub-unit through the corresponding phase sequence number and IP address sent by each passive wireless digital current transformer sub-unit.

[0007] In one embodiment of the present invention, the passive wireless digital current transformer extension includes: the passive wireless digital current transformer extension includes: a receiving module, configured to receive the synchronization signal sent from the host; an extension processing module, configured to enter an external interrupt mode after receiving the synchronization signal and cause a delay time to be set for a delay period, so as to send a collection command for controlling the collection of current signals after the delay time is completed and a signal transmission command corresponding to the collection of digital current signal frames formed by processing the collected current signals; and an isolation module, connected to the extension processing module, configured to receive... The system includes: a current acquisition command for acquiring current signals and a processed current acquisition command for sending the acquired current signals; a measurement CT module and a power-feeding CT module; an acquisition module connected to the isolation module and the measurement CT, used to receive the processed current acquisition command and acquire current signals from the measurement CT, so that the acquired current signals can be sent to the sub-unit processing module through the isolation module for processing to form a digital current signal frame; a sub-unit sending module connected to the sub-unit processing module, used to send the digital current signal frame; and a power supply module connected to the sub-unit processing module and the power-feeding CT, used to supply power to each module.

[0008] In one embodiment of the present invention, the extension processing module includes: a receiving unit for receiving the synchronization signal and the acquired current signal; an external interrupt unit connected to the receiving unit for executing an external interrupt after receiving the synchronization signal and sending an external interrupt signal; a delay unit connected to the external interrupt unit for setting a delay time and delaying the delay time, and sending a delay completion signal after the delay is completed; an acquisition control unit connected to the delay unit for receiving the delay completion signal and interrupting the delay of the delay unit, and sending an acquisition command for acquiring the current signal; and a signal processing and transmission control unit connected to the receiving unit for receiving and transmitting a signal transmission command for processing the acquired current signal to form a digital current signal frame.

[0009] In one embodiment of the present invention, the host includes: a host processing module for timing and sending the interrupt signal after the timing is completed; a drive circuit connected to the host processing module for receiving the interrupt signal and sending a drive command; and a host transmitting module connected to the drive circuit for receiving the drive command and transmitting a synchronous current signal.

[0010] In one embodiment of the present invention, the host further includes one or more of the following: a WIFI module, a wireless signal receiver, a 4G module, and an optical fiber module.

[0011] To achieve the above and other related objectives, this invention provides a passive wireless current detection synchronization method for a three-phase power line, applied to at least three passive wireless digital current transformer sub-units connected and matched to a host. The method includes: receiving a synchronization signal sent by the host; controlling the passive wireless digital current transformer sub-unit to synchronously acquire current signals with other wireless digital current transformer sub-units based on the synchronization signal and the corresponding delay time of the sub-unit; and forming a digital current signal frame from the acquired current signals and sending it to the host.

[0012] To achieve the above and other related objectives, the present invention provides an electronic terminal, characterized in that it includes a memory for storing computer programs and a processor for executing the passive wireless current detection and synchronization method for three-phase power lines.

[0013] To achieve the above and other related objectives, the present invention provides a computer-readable storage medium, characterized in that the computer program, when executed by a processor, implements a passive wireless current detection and synchronization method for the three-phase power line.

[0014] As described above, the passive wireless current detection synchronization system, method, and terminal for three-phase power lines of the present invention have the following beneficial effects: The host sends a synchronization signal to at least three passive wireless digital current transformer sub-units matched with it. Each passive wireless digital current transformer sub-unit receives the synchronization signal sent by the host and, according to the synchronization signal and the delay time set by the sub-unit, controls the sub-unit to synchronously collect current signals with other wireless digital current transformer sub-units, and sends the collected current signals into digital current signal frames to the host. This achieves passive wireless current detection synchronization for three-phase power lines and solves the problems of phase difference, harmonic analysis errors, etc., caused by delay errors in the system. Attached Figure Description

[0015] Figure 1 The diagram shown is a schematic diagram of a passive wireless current detection and synchronization system for a three-phase power line according to one embodiment of the present invention.

[0016] Figure 2 The diagram shown is a schematic representation of a passive wireless current detection and synchronization system for a three-phase power line according to one embodiment of the present invention.

[0017] Figure 3 The diagram shown is a schematic diagram of a passive wireless current detection and synchronization system for a three-phase power line according to one embodiment of the present invention.

[0018] Figure 4The diagram shows the delay time of a passive wireless current detection and synchronization system for a three-phase power line according to one embodiment of the present invention.

[0019] Figure 5 The diagram shown is a schematic diagram of the host structure of a passive wireless current detection and synchronization system for a three-phase power line according to one embodiment of the present invention.

[0020] Figure 6 The diagram shown is a schematic diagram of the sub-unit structure of a passive wireless current detection and synchronization system for a three-phase power line according to one embodiment of the present invention.

[0021] Figure 7 The diagram shown is a schematic diagram of the sub-unit process of a passive wireless current detection and synchronization system for a three-phase power line according to one embodiment of the present invention.

[0022] Figure 8 The diagram shown is a schematic flowchart of a passive wireless current detection and synchronization system for a three-phase power line according to one embodiment of the present invention.

[0023] Figure 9 The diagram shown is a schematic diagram of an electronic terminal structure according to one embodiment of the present invention. Detailed Implementation

[0024] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0025] Please see Figures 1 to 9 It is understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0026] Throughout this specification, when it is said that a part is "connected" to another part, this includes not only "direct connection" but also "indirect connection" by placing other elements in between. Furthermore, when it is said that a part "includes" a certain constituent element, unless otherwise stated otherwise, this does not exclude other constituent elements, but rather means that other constituent elements may also be included.

[0027] The terms "first," "second," and "third," etc., used herein are for the purpose of describing various parts, components, regions, layers, and / or segments, but are not limiting. These terms are used only to distinguish one part, component, region, layer, or segment from others. Therefore, the "first part," "component," "region," "layer," or "segment" described below may refer to a "second part," "component," "region," "layer," or "segment" without departing from the scope of this invention.

[0028] Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, operation, element, component, item, kind, and / or group, but do not preclude the presence, occurrence, or addition of one or more other features, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition arise only when combinations of elements, functions, or operations are inherently mutually exclusive in some manner.

[0029] Currently, wired power transformers are not permitted for current signal acquisition on 10kV, 35kV, and higher voltage transmission lines because the signal lines would introduce high-voltage electricity into the secondary system, posing a safety hazard. If the distance is close, this could inevitably lead to grounding accidents. While self-powered wireless current transformers are available on the market, these either suffer from low sampling rates due to transmission channel frequency limitations, or can only be used for current acquisition on a single transmission conductor, not for simultaneous sampling of three-phase lines. Furthermore, system delay errors can cause analysis errors related to phase difference and harmonics.

[0030] Therefore, this invention provides a passive wireless current detection synchronization system, method, and terminal for three-phase power lines. The host synchronously transmits each single-phase current signal from at least three synchronized three-phase current signals to at least three passive wireless digital current transformer (DCF) units respectively matched with it. Each DCF unit receives a single-phase current signal sent by the host and, based on the single-phase current signal and the corresponding delay time of the DCF unit, controls the DCF unit to start collecting current, so that its start-up current collection time is synchronized with the start-up current collection times of other DCF units. This invention achieves passive wireless current detection synchronization for three-phase power lines, solving the problems of phase difference and harmonic analysis errors caused by delay errors in the system.

[0031] like Figures 1 to 3 As shown in the figure, the present invention provides a schematic diagram of a passive wireless current detection and synchronization system for a three-phase power line.

[0032] The passive wireless current detection and synchronization system for the three-phase power line includes:

[0033] At least three passive wireless digital current transformer sub-units 2; a host 1, connected to at least three of the passive wireless digital current transformer sub-units 2, for sending synchronization signals to the at least three of the passive wireless digital current transformer sub-units 2; specifically, the synchronization signal sent by the host to the passive wireless digital current transformer sub-units is a mixed signal of infrared and laser, and the synchronization signal is uniformly and simultaneously sent by the host to the passive wireless digital current transformer sub-units;

[0034] For example, the three-phase power line typically includes a three-phase three-wire system (A, B, C), a three-phase four-wire system (A, B, C, N), and a three-phase five-wire power line system (A, B, C, N, GND), where A, B, C, N, and GND are the codes for three passive wireless digital current transformer sub-units.

[0035] Each passive wireless digital current transformer sub-unit 2 is used to receive the synchronization signal sent by the host 1, and according to the synchronization signal and the delay time set by the sub-unit, controls the passive wireless digital current transformer sub-unit 2 to synchronously collect current signals with other wireless digital current transformer sub-units 2, and forms the collected current signals into digital current signal frames and sends them to the host 1. Specifically, the timing of receiving the synchronization signal by each sub-unit 2 is different, so a delay time needs to be set for each sub-unit 2 to ensure that the passive wireless digital current transformer sub-unit... 2. The passive wireless digital current transformer sub-unit 2 collects current at the same time as other wireless digital current transformer sub-units 2 to avoid time differences in the current signals collected by the sub-units due to different collection times. The passive wireless digital current transformer sub-unit processes the collected current signals to form digital current signal frames. Taking one passive wireless digital current transformer sub-unit 2 as an example, when the passive wireless digital current transformer sub-unit 2 receives the synchronization signal, it controls the passive wireless digital current transformer sub-unit 2 to delay the current collection. The time for delaying the current collection is the delay time. The process is the same for other wireless digital current transformer sub-units 2.

[0036] In one embodiment, the calculation of the delay time includes: obtaining the transmission time of the synchronization signal sent by the host and the response time of the passive wireless digital current transformer sub-unit 2 in response to the synchronization signal, and determining the transmission response time difference corresponding to the synchronization signal; obtaining the delay time of the corresponding passive wireless digital current transformer sub-unit based on the fixed response time of the corresponding passive wireless digital current transformer sub-unit 2 and the transmission and reception time difference; specifically, the time difference between the transmission time of the synchronization signal sent by the host 1 and the response time of the synchronization signal of the passive wireless digital current transformer sub-unit 2 is measured in advance and recorded in a single chip, and then the single chip 201 is installed in its corresponding passive wireless digital current transformer sub-unit 2, the fixed response time is the time from the host 1 transmitting the current signal to the start of current acquisition in the passive wireless digital current transformer sub-unit 2 set in advance, the fixed response time of all passive wireless digital current transformer sub-units 2 is the same, the delay time is the difference between the fixed response time and the time difference, and the delay time is greater than zero;

[0037] For example, there are four passive wireless digital current transformer sub-units (hereinafter referred to as sub-units): A, B, C, and X. Taking sub-unit X as an example, the time difference tdx between the leading edge / rising edge of the laser pulse emitted by the main transmitter and the leading edge / falling edge of the signal received by the receiver of sub-unit X is measured with an oscilloscope and recorded in a microcontroller. Then, the microcontroller is installed in its corresponding sub-unit A. ts is set as a fixed time, and ts is also recorded in the microcontroller before installation. Figure 4 As shown, the required delay time tjx = ts - tdx is needed to start collecting the current. The calculation method for the delay time of extensions A, B and C is the same.

[0038] In one embodiment, the matching method between the host 1 and each of the passive wireless digital current transformer sub-units 2 includes: the host matching each passive wireless digital current transformer sub-unit 2 with the corresponding phase sequence number and IP address sent by each sub-unit 2; specifically, after the passive wireless digital current transformer sub-unit 2 is installed, it will send its own phase sequence number and IP address to the host 1. If a new passive wireless digital current transformer sub-unit 2 is installed, the new sub-unit 2 will send its own phase sequence number and IP address to the host 1, and the host 1 will transmit a synchronization signal. For example, if there were originally three passive wireless digital current transformer sub-units 2, the host 1 would send the synchronization signal to the three sub-units 2. If a new sub-unit 2 is added, the host 1 would send the synchronization signal to all four sub-units 2.

[0039] In one embodiment, the passive wireless digital current transformer unit 2 includes:

[0040] The receiving module 20 is used to receive the synchronization signal sent from the host 2; specifically, the receiving module 20 may be a laser beam receiver.

[0041] The extension processing module 21 is used to enter the external interrupt mode after receiving the synchronization signal and cause the delay device to delay for the delay time, so as to send a collection instruction for controlling the collection of current signal after the delay device has delayed for the delay time, and a corresponding signal sending instruction for sending the digital current signal frame formed by processing the collected current signal.

[0042] Isolation module 22 is connected to the sub-unit processing module 21 and is used to receive the current acquisition signal and send the processed current acquisition command signal;

[0043] Measurement CT module 24;

[0044] The acquisition module 23 is connected to the isolation module 22 and the measurement CT module 24. It is used to receive the processed current acquisition command and acquire current signals from the measurement CT module 24, so that the acquired current signals can be sent to the sub-processing module for processing through the isolation module.

[0045] Extension sending module 25 is connected to extension processing module 21 and is used to send the digital current signal frame;

[0046] Specifically, the sub-unit processing module 21 has a power supply interface, an IO drive interface, and two or more SPI interfaces, preferably a first SPI interface and a second SPI interface (not shown in the figure); the sub-unit processing module 21 can be a microcontroller core board, preferably using an STM32F405RGT6 chip; the isolation module 22 is an SPI isolation module, preferably using an ADuM3151 chip, and preferably, the isolation module 22 is connected to the sub-unit processing module 21 through the first SPI interface; the acquisition module 23 is a single-phase current acquisition module, preferably using an ADE6. The receiver module 20 is connected to the extension processing module 21 via the IO driver interface, and the extension transmitting module 25 is connected to the extension processing module 21 via the second SPI interface. The receiver module 20 and the extension transmitting module 25 are installed at any position on the passive wireless digital current transformer extension 2. Preferably, the receiver module 20 is installed at the lower part of the passive wireless digital current transformer extension 2 to facilitate receiving the synchronization signal. The extension transmitting module 25 preferably uses WiFi, and the WiFi can be based on the ESP8266EX chip's ALK8266. The WIFI module; preferably, the interruption of the extension processing module 21 can be achieved by the microcontroller being mounted on the extension processing module, and the connection module being connected to the pin of the microcontroller set as an external interrupt. The external interrupt mode is that the microcontroller is interrupted, meaning the microcontroller cannot receive or send current signals, i.e., it cannot send the acquisition command for the acquired current signal, the corresponding signal transmission command for the digital current signal frame formed by processing the acquired current signal, receive the synchronization signal, or receive the acquired current signal. The delay function of the delay device is to delay the time for receiving and sending current signals. After the delay time is reached, the delay device is interrupted, and the extension processing module 21 resumes connection to receive signals. The delay time of the delay unit is the delay time corresponding to the passive wireless digital current transformer sub-unit 2; the isolation module is used for the conversion between high-level signals and low-level signals. The signal in the acquisition module 23 is a high-level signal, and the signal in the sub-unit processing module 21 is a low-level signal. The signal transmission between the acquisition module 23 and the sub-unit processing module 21 needs to be converted; the digital current signal frame formed by the processing of the acquired current signal is that the acquisition module sends an acquired current signal through the isolation module, and the sub-unit processing module receives the acquired current signals one by one within a certain range of time. These acquired current signals form the digital current signal frame.

[0047] Power supply CT module 26;

[0048] The power supply module 27 is connected to the sub-unit processing module 21 and the power CT module 26, and is used to supply power to each module.

[0049] Specifically, the power supply system is connected to the sub-unit processing module 21 via the power supply interface. The power supply system 27 includes a power extraction module 207 and an energy storage module 217. The power extraction CT module 26 is connected to the power extraction module 207, the power extraction module 207 is connected to the energy storage module 217, and the energy storage module 217 is connected to the sub-unit processing module 21. The power supply system 27 can provide 12V / 3W power.

[0050] In one embodiment, the extension processing module includes:

[0051] The receiving unit 201 is used to receive the synchronization signal and the acquired current signal; the external interrupt unit 211 is connected to the receiving unit 201 and is used to execute an external interrupt after receiving the synchronization signal and send an external interrupt signal; specifically, executing the external interrupt means not sending the acquisition instruction of the acquired current signal, sending the corresponding signal transmission instruction of the digital current signal frame formed by processing the acquired current signal, receiving the synchronization signal and receiving the acquired current signal;

[0052] The delay unit 231 is connected to the external interrupt unit 211 and is used to set a delay time and delay for the specified time, and send a delay completion signal after the delay is completed; specifically, setting the delay time is to calculate the difference between the fixed delay time and the time difference.

[0053] The acquisition control unit 241 is connected to the delay unit 231 and is used to receive the delay completion signal and interrupt the delay of the delay unit, and send an acquisition command for the acquisition current signal.

[0054] The signal transmission control unit 251 is connected to the receiving unit 201 and is used to receive and transmit the signal transmission command for generating the digital current signal frame from the acquired current signal.

[0055] For example, after receiving the synchronization signal, the external interrupt unit pulls the signal pin level low and triggers an external interrupt in the extension CPU, entering the external interrupt unit. The external interrupt unit is mainly used to start the delay unit, that is, to start the internal delay unit of the CPU, whose delay value is the delay time. After the delay time ends, the delay unit interrupt is triggered, and the acquisition control unit is entered. In the acquisition control unit, the delay interrupt subroutine is interrupted. In the delay interrupt subroutine, the acquisition subroutine is reset, the acquisition count is cleared, and the acquisition subroutine is started.

[0056] In one embodiment, the host 1 includes:

[0057] The host processing module 11 is used for timing and sending the timer interrupt signal. Specifically, the host processing module 11 has an SPI interface, an asynchronous serial port, and an IO interface (not shown in the figure). The timer 101 is set on the host processing module 11, and the host processing module 11 uses an internal timer to keep time. The timer will be interrupted at regular intervals.

[0058] The drive circuit 12 is connected to the host processing module 11 and is used to receive the timer interrupt signal and send drive commands.

[0059] The host transmitting module 13 is connected to the driving circuit 12 and is used to receive the driving command and transmit the synchronous current signal. Specifically, the transmitting module is preferably a laser beam transmitter, which is installed at any position of the host. Preferably, the laser beam transmitter is installed on the top of the host electrical control box, which is generally installed on a utility pole.

[0060] In one embodiment, the host further includes one or more of a wireless signal receiver 14, a 4G module 15, and an optical fiber module 16; specifically, the wireless signal receiver 14 is connected to the host processing module via an SPI interface, and the wireless signal receiver 14 is preferably WiFi; the 4G module 15 is connected to the host processing module via an asynchronous serial port.

[0061] To better illustrate the passive wireless current detection and synchronization system for the above-mentioned three-phase power lines, the present invention provides the following specific embodiments.

[0062] Example 1: A passive wireless current detection and synchronization method system for three-phase power lines, such as... Figures 5 to 7 As shown.

[0063] The system includes: a main unit and a passive wireless digital current transformer sub-unit (hereinafter referred to as the sub-unit);

[0064] The host includes a host CPU core board module, a host WIFI communication module, a laser beam sensor transmitter, and a 4G module.

[0065] The extension unit includes an extension unit CPU core board module, a data acquisition module, an extension unit WIFI communication module, and a laser beam sensor receiver;

[0066] The laser beam sensor transmitter is installed on the top of the main control box, which is usually installed on a utility pole about 10m away from the power line. The sub-unit is installed on the power line conductor, and the laser beam sensor receiver is installed at the bottom of the sub-unit to receive the synchronization signal sent by the transmitter. The effective transmission distance of the laser beam transmitter is 15 meters, the pointing angle is 15°, and it covers the width of the power line. The laser beam receiver usually has a response delay of 3 to 5ms.

[0067] Implementation scheme of the system:

[0068] The host CPU core board module uses an internal timer to drive the laser beam sensor transmitter to emit a synchronization signal every 10 minutes. Alternatively, the host will drive the beam sensor to emit a synchronization signal after a new extension sends a connection signal.

[0069] After receiving the synchronization signal, the laser beam sensor receiver of the extension unit pulls the signal pin low and triggers an external interrupt in the extension unit's CPU, entering the external interrupt subroutine. The external interrupt subroutine is mainly used to start the delay subroutine, i.e., to start the CPU's internal timer. Its timing value is calculated from the delay td of the laser beam sensor, which is calculated using an oscilloscope to measure the time difference td between the leading edge (rising edge) of the laser pulse emitted by the transmitter and the leading edge (falling edge) of the signal received by the receiver. Here, ts is a fixed value, representing the total synchronization delay of all extension units, i.e., the delay between the leading edge of the laser synchronization signal and the start of the current acquisition program. After the timer delay ends, a timer interrupt is triggered, and the timer interrupt subroutine is entered. In the timer interrupt subroutine, the acquisition subroutine is reset, the acquisition count is cleared, and the acquisition module is started. After the extension unit completes the acquisition of 32 measurement points within 20ms, the current waveform acquisition data for one cycle within that time period is sent to the host unit's WIFI module via the extension unit's WIFI module.

[0070] The host CPU core board module connects to the host WIFI module through a high-speed SPI interface, establishes a WIFI network through the module, and is set up as a server. After receiving the current waveforms of each line, the host CPU determines the fault point and fault type through a fault identification algorithm, and then sends it to the platform through the 4G network.

[0071] like Figure 8 As shown, the present invention provides a passive wireless current detection and synchronization method for three-phase power lines.

[0072] The method, applied to at least three passive wireless digital current transformer extensions connected and matched to a host, includes:

[0073] Receives a synchronization signal sent by the host; controls the passive wireless digital current transformer sub-unit to synchronously collect current signals with other wireless digital current transformer sub-units based on the synchronization signal and the corresponding delay time of the sub-unit; and forms the collected current signals into digital current signal frames and sends them to the host.

[0074] Specifically, the above methods can be implemented through the following steps;

[0075] Step S81: Obtain the delay value;

[0076] Step S82 sends the local machine's sequence number and IP address to the outside;

[0077] Step S83: Receive synchronization signal;

[0078] Step S84: Is the synchronization signal received?

[0079] If the synchronization signal is received in step S85, the passive wireless digital current transformer unit stops the current acquisition and transmission process, calculates the delay time based on the delay value, and starts the passive wireless digital current transformer unit delay device to delay; otherwise, it re-determines whether the synchronization signal has been received. Specifically, the calculation method of the delay time is the same as the calculation method of the passive wireless current detection and synchronization system of the three-phase power line.

[0080] Has step S86 completed its delay?

[0081] If the delay is completed in step S87, the number of acquisition counts is reset to zero and the current acquisition and transmission process is started; otherwise, the delay is re-evaluated.

[0082] like Figure 9 This is a schematic diagram of the structure of an electronic terminal 900 according to an embodiment of the present invention.

[0083] The electronic terminal 900 includes: a memory 902 and a processor 901. The memory 902 is used to store computer programs; the processor 901 runs the computer programs to implement, for example... Figure 8 The present invention relates to a passive wireless current detection and synchronization method for a three-phase power line.

[0084] Specifically, the number of memories 902 can be one or more, and the number of processors 901 can be one or more. Figure 9 Let's take one example each.

[0085] Specifically, the processor 901 in the electronic terminal 900 will perform as follows: Figure 8The steps described involve loading one or more instructions corresponding to the process of an application into memory 902, and then having processor 901 run the application stored in the first memory 902, thereby achieving the following: Figure 8 The various functions of the passive wireless current detection and synchronization method for a three-phase power line are described above.

[0086] Specifically, the memory 902 may include, but is not limited to, high-speed random access memory and non-volatile memory. For example, one or more disk storage devices, flash memory devices, or other non-volatile solid-state storage devices; the processor 901 may include, but is not limited to, a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0087] Specifically, the processor 901 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0088] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements a passive wireless current detection and synchronization method for a three-phase power line.

[0089] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented using computer program-related hardware. The aforementioned computer program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0090] In the embodiments provided in this application, the computer-readable and writable storage medium may include read-only memory, random access memory, EEPROM, CD-ROM or other optical disc storage devices, disk storage devices or other magnetic storage devices, flash memory, USB flash drive, portable hard drive, or any other medium capable of storing desired program code in the form of instructions or data structures and accessible by a computer. Additionally, any connection may be appropriately referred to as a computer-readable medium. For example, if instructions are transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of the medium. However, it should be understood that computer-readable and writable storage media and data storage media do not include connections, carrier waves, signals, or other transient media, but are intended for non-transient, tangible storage media. The disks and optical discs used in the application include compact discs (CDs), laser discs, optical discs, digital multifunction discs (DVDs), floppy disks, and Blu-ray discs, where disks typically copy data magnetically, while optical discs use lasers to copy data optically.

[0091] In summary, the passive wireless current detection synchronization system, method, and terminal for three-phase power lines provided by this invention involve a host computer sending a synchronization signal to at least three matched passive wireless digital current transformer sub-units. Each passive wireless digital current transformer sub-unit receives the synchronization signal sent by the host computer and, based on the synchronization signal and a delay time set by the sub-unit, controls itself to synchronously collect current signals with other wireless digital current transformer sub-units. The collected current signals are then formed into digital current signal frames and sent to the host computer. This achieves passive wireless current detection synchronization for three-phase power lines and solves the problems of phase difference and harmonic analysis errors caused by delay errors in the system. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0092] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A passive wireless current detection and synchronization system for a three-phase power line, characterized in that, The system includes: At least three passive wireless digital current transformer extensions; The host is connected to at least three of the passive wireless digital current transformer sub-units that are matched with it, and is used to send synchronization signals to the at least three of the passive wireless digital current transformer sub-units that are matched with it. Each passive wireless digital current transformer (DCF) receiver receives the synchronization signal sent by the host and, based on the synchronization signal and a set delay time, controls itself to synchronously acquire current signals with other DCF receivers. The acquired current signals are then formed into digital current signal frames and sent to the host. The delay time is calculated by: obtaining the transmission time of the synchronization signal sent by the host and the response time of the DCF receiver to the synchronization signal; determining the time difference corresponding to the synchronization signal based on the transmission time and the response time; and using the difference between the fixed response time and the time difference as the delay time for the corresponding DCF receiver. The fixed response time is a preset total delay from the host transmitting the synchronization signal to the start of current acquisition, and all DCF receivers have the same fixed response time. The passive wireless digital current transformer extension unit includes an extension unit processing module, which includes: A receiving unit is used to receive the synchronization signal and the acquired current signal; An external interrupt unit, connected to the receiving unit, is used to execute an external interrupt after receiving the synchronization signal and to send an external interrupt signal; The delay unit is connected to the external interrupt unit and is used to set the delay time and delay for the delay time, and send a delay completion signal after the delay is completed. The acquisition control unit is connected to the delay unit and is used to receive the delay completion signal and interrupt the delay of the delay unit, and send an acquisition command for the current signal. The signal processing and transmission control unit is connected to the receiving unit and is used to receive and transmit the signal transmission command for generating the digital current signal frame from the acquired current signal processing.

2. The passive wireless current detection and synchronization system for a three-phase power line according to claim 1, characterized in that, The matching methods between the host and each passive wireless digital current transformer sub-unit include: The host matches each passive wireless digital current transformer sub-unit with the corresponding phase number and IP address sent by each sub-unit.

3. The passive wireless current detection and synchronization system for a three-phase power line according to claim 1, characterized in that, The passive wireless digital current transformer extension includes: A receiving module is used to receive the synchronization signal sent from the host. The extension processing module is used to enter the external interrupt mode after receiving the synchronization signal and cause the delay device to delay for the delay time, so as to send a collection instruction for controlling the collection of current signal after the delay time ends, and a corresponding signal sending instruction for sending the digital current signal frame formed by processing the collected current signal. An isolation module, connected to the sub-unit processing module, is used to receive the acquisition command of the acquisition current signal and send the processed acquisition command of the acquisition current signal. Measurement CT module and power-feeding CT module; The acquisition module, connected to the isolation module and the measuring CT, is used to receive the processed current acquisition command and acquire current signals from the measuring CT, so that the acquired current signals can be sent to the sub-processing module through the isolation module for processing to form a digital current signal frame. The extension transmitting module is connected to the extension processing module and is used to transmit the digital current signal frame; The power supply module is connected to the sub-unit processing module and the power CT, and is used to supply power to each module.

4. The passive wireless current detection and synchronization system for a three-phase power line according to claim 1, characterized in that, The host includes: The host processing module is used for timing and sending a timer interrupt signal after the timing period ends. The driving circuit, connected to the host processing module, is used to receive the timer interrupt signal and send driving instructions; The host transmitting module is connected to the driving circuit and is used to receive the driving command and transmit a synchronous current signal.

5. The passive wireless current detection and synchronization system for a three-phase power line according to claim 4, characterized in that, The host also includes one or more of the following: a WIFI module, a wireless signal receiver, a 4G module, and an optical fiber module.

6. A passive wireless current detection and synchronization method for a three-phase power line, characterized in that, The method, applied to at least three passive wireless digital current transformer extensions connected and matched to a host, includes: Receive synchronization signals sent by the host; The passive wireless digital current transformer sub-unit is controlled to synchronously acquire current signals with other wireless digital current transformer sub-units based on the synchronization signal and the corresponding delay time. The delay time is calculated by: obtaining the transmission time of the synchronization signal sent by the host and the response time of the passive wireless digital current transformer sub-unit in response to the synchronization signal, and determining the time difference corresponding to the synchronization signal based on the transmission time and the response time; using the difference between the fixed response time and the time difference as the delay time corresponding to the passive wireless digital current transformer sub-unit; the fixed response time is the preset total delay from the host transmitting the synchronization signal to the start of current acquisition, and the fixed response time of all passive wireless digital current transformer sub-units is the same. The collected current signal is formed into a digital current signal frame and sent to the host.

7. An electronic terminal, characterized in that, Memory, used to store computer programs; A processor for executing the passive wireless current detection and synchronization method for a three-phase power line as described in claim 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the passive wireless current detection and synchronization method for the three-phase power line as described in claim 6.

Images