CN113225280A - Distortion pulse current self-adaptive dynamic adjustment method in power frequency communication and self-adaptive dynamic adjustment sending device - Google Patents
Distortion pulse current self-adaptive dynamic adjustment method in power frequency communication and self-adaptive dynamic adjustment sending device Download PDFInfo
- Publication number
- CN113225280A CN113225280A CN202110482979.0A CN202110482979A CN113225280A CN 113225280 A CN113225280 A CN 113225280A CN 202110482979 A CN202110482979 A CN 202110482979A CN 113225280 A CN113225280 A CN 113225280A
- Authority
- CN
- China
- Prior art keywords
- power frequency
- pulse current
- frequency voltage
- modulation
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/06—Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B14/00—Transmission systems not characterised by the medium used for transmission
- H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B14/00—Transmission systems not characterised by the medium used for transmission
- H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
- H04B14/04—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using pulse code modulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/06—Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection
- H04L25/069—Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection by detecting edges or zero crossings
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
The invention discloses a method and a device for adaptively and dynamically adjusting distorted pulse current in power frequency communication. The method comprises the following steps: modulating and coding the power frequency voltage signal; collecting load current on a corresponding phase current circuit of the power frequency voltage modulation device; extracting and identifying effective distortion pulse current signals and demodulating coded information; adjusting the next power frequency voltage modulation phase angle according to the identified average value and the maximum value of the amplitude of the distorted pulse current signal; and modulating and coding the power frequency voltage signal according to the adjusted power frequency voltage modulation phase angle. The device comprises a voltage zero-crossing detection circuit, a power frequency voltage modulation circuit, a distortion pulse current sampling circuit, a control unit, an uplink communicator and a memory. The invention can adjust the power frequency voltage modulation phase opening angle according to the power grid operating parameters and the environmental changes, and adaptively and dynamically adjust the distorted pulse current to ensure the safety of the power frequency voltage modulation circuit of the transmitting device and the identification success rate of the receiving device.
Description
Technical Field
The invention relates to the technical field of instruments and meters, in particular to a self-adaptive dynamic adjustment method and a self-adaptive dynamic adjustment transmitting device for distorted pulse current in power frequency communication.
Background
At present, an important work of an electricity utilization information acquisition system and a low-voltage distribution network system is to realize automatic identification of a low-voltage distribution network household variable relation and a transformer area physical topological relation, and through an accurate transformer area household variable relation, the problems of low transformer area meter reading success rate, inaccurate transformer area line loss calculation and the like caused by inaccurate transformer area attribution relation can be found in time. The station area diversity relation and topology identification are generally realized by adopting a power frequency communication technology, the main principle of the power frequency communication technology is that a power frequency voltage fundamental wave zero-crossing modulation method is utilized, weak distortion of a modulation voltage or current waveform near a zero-crossing point is utilized to carry information, and information transmission is realized by utilizing the relative change and invariance of voltage or current of adjacent periods.
The whole power frequency communication system comprises a power frequency voltage modulation device and a corresponding distortion pulse current receiving and identifying device, wherein the power frequency voltage modulation and sending device is generally installed at the side of a low-voltage distribution station meter box, a branch box and other end users, and the distortion pulse current receiving and identifying device is generally installed at the low-voltage distribution station branch box and the low-voltage side of a distribution transformer. The main working process is that the power frequency voltage modulation transmitting device controls the switch tube to be conducted through a certain phase angle before the power frequency voltage zero crossing point, an instantaneous distortion pulse current signal is generated on a low-voltage distribution line at the corresponding zero crossing point moment, the distortion pulse current signal can be superposed on the load current at the voltage zero crossing point moment and can be transmitted to the transformer side of a distribution area along a power line received by the modulation device, the distortion pulse current receiving device is arranged at the position of the transformer, the distortion pulse current signal is collected and demodulated by the distortion pulse current receiving device, and therefore the identification of the distortion pulse current signal is completed. According to a certain modulation coding method, the power frequency voltage zero crossing point is continuously modulated for multiple times, multiple distorted pulse current signals can be generated, and the identification end identifies and demodulates the signals, so that one-time communication can be completed. The modulation is carried out before the zero crossing point of the power frequency voltage waveform, the energy required by the modulation is minimum, and the impact on the power grid and the voltage and current distortion caused in the modulation process can be controlled within a reasonable range. The signal transmitted from the power frequency voltage modulation transmitting device to the distorted pulse current receiving and identifying device is called an uplink modulation signal, and the uplink modulation signal carries modulation information by utilizing a current fundamental wave shape.
The existing power frequency voltage modulation consists of a current limiting device, a switching tube and a switching tube driving circuit, wherein the current limiting device is used for controlling the magnitude of generated distortion pulse current, and the switching tube driving circuit is used for driving the switching tube to be switched on and switched off. The current-limiting device adopts an inductor or a resistor, the switching tube adopts switching devices such as a silicon controlled rectifier, an MOS tube and an IGBT, the driving circuit of the switching tube adopts a pulse transformer and a silicon controlled rectifier optocoupler, and the control unit can adopt a common singlechip or a micro-controller. The power frequency voltage modulation and transmission device is only provided with the power frequency voltage modulation circuit, and the transmission device without the feedback loop cannot know the size of a distorted pulse current signal generated by modulating the power frequency voltage, so that the distorted pulse current signal is generated by modulating the power frequency voltage signal by adopting a fixed phase angle.
The modulation transmission device manufactured based on the fixed phase angle modulation method has the following problems:
(1) vulnerable sending device
The power grid has complex running environment, different line impedances and different application environments, the size of a distorted pulse current signal generated by modulating the power frequency voltage by the same phase angle is different, the size of the generated distorted pulse current signal can be influenced by the too large or too small phase angle modulated by the power frequency voltage, if the generated distorted pulse current is too large, a switching tube of the sending device is easily damaged, and the device is easily damaged or the nearby switching is easily tripped.
(2) The failure of self-adapting dynamic adjustment of distorted pulse current signal causes low success rate of receiving end identification
The switch tube of the sending device can be damaged when the distorted pulse current signal is too large, but the switch tube is too small, and the receiving end recognition device can not recognize or recognize by mistake, so that the recognition rate of the distorted pulse current signal of the receiving end is too low or cannot recognize at all.
Disclosure of Invention
The invention aims to solve the technical problem of providing a distorted pulse current self-adaptive dynamic adjusting method and a self-adaptive dynamic adjusting and sending device in power frequency communication, which can dynamically adjust the amplitude of a distorted pulse current signal according to the actual conditions of different transformer district environments and ensure that the amplitude of the distorted pulse current signal falls in a set reasonable safety interval, thereby not only avoiding that the sending device is damaged or the switch is tripped by mistake due to overlarge distorted pulse current, but also avoiding that the identification rate of the distorted pulse current signal at a receiving end is too low or the distorted pulse current signal cannot be identified at all due to undersize distorted pulse current.
In order to solve the technical problem, the invention provides a distortion pulse current self-adaptive dynamic adjustment method in power frequency communication, which comprises the following steps:
modulating and coding the power frequency voltage signal;
collecting load current on a corresponding phase current circuit of the power frequency voltage modulation device;
extracting and identifying effective distortion pulse current signals and demodulating coded information;
adjusting the next power frequency voltage modulation phase angle according to the identified average value and the maximum value of the amplitude of the distorted pulse current signal;
and modulating and coding the power frequency voltage signal according to the adjusted power frequency voltage modulation phase angle.
Further, the step of modulating and encoding the power frequency voltage signal comprises the following steps:
identifying zero crossing point information in real time according to a power frequency voltage zero crossing detection circuit;
receiving a starting power frequency voltage modulation command of a waiting superior terminal, and if the starting modulation command is received, reading a current power frequency voltage modulation phase angle stored in a memory and controlling a power frequency voltage modulation circuit to modulate;
and sequentially modulating the power frequency voltage according to a certain modulation coding method until all coding information which can represent the identification code or the device address is sent.
Furthermore, the power frequency voltage modulation phase angle ranges from 300 microseconds to 900 microseconds.
Furthermore, within a set time period, the power frequency voltage modulation phase angle is firstly defaulted to be 600 microseconds.
Furthermore, the step of extracting the identification valid distortion pulse current signal and demodulating the coded information comprises the following steps:
according to the characteristic that power frequency voltage modulation utilizes voltage waveform zero-crossing region modulation, a detection time window is arranged near a voltage zero-crossing point, and original load current data in the corresponding time window are analyzed;
calculating the amplitude of the pulse current signal in each current cycle detection time window;
comparing the amplitude of the distorted pulse current signal extracted and calculated in each current cycle detection time window with a set threshold identification threshold, and if the amplitude is greater than the threshold identification threshold, judging the distorted pulse current signal as an effective distorted pulse current signal; if the amplitude of the extracted and calculated distortion pulse current signal is smaller than a set threshold value, judging the distortion pulse current signal to be an invalid distortion pulse current signal;
and demodulating each effective distortion pulse current signal according to a set coding rule, and identifying coded information.
Further, in the step of adjusting the next power frequency voltage modulation phase angle according to the identified distortion pulse current signal amplitude average value and maximum value, the step of adjusting the next power frequency voltage modulation phase angle includes:
calculating the average value Iavg and the maximum value Imax of the amplitude values of a plurality of distorted pulse current signals generated by each modulation;
adjusting the next power frequency voltage modulation phase angle according to the following strategy:
modulating at any time, and when the average value Iavg of the generated pulse distortion current meets 10< Iavg <55, stepping the phase angle for modulating at the next time by 150;
modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 55-65 of Iavg and 100 of Imax, stepping 120 the phase angle of the next modulation;
modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 65-75 of Iavg and 100 of Imax, stepping 80 the phase angle of the next modulation;
and (4) modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 80-85 Iavg and 100 Imax, stepping the phase angle by 50 in the next modulation.
And (4) modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 80-85 Iavg and 100 Imax, stepping the phase angle by 30 for the next modulation.
Modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet the conditions that the Iavg is more than or equal to 85 and less than or equal to 95 and the Imax is less than or equal to 100, the phase angle of the next modulation is not changed, and the phase angle of the previous modulation is still kept;
modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 105-Iavg or 110-Imax, reducing the phase angle of the next modulation by 100;
and (3) modulating at any time, when the generated pulse distortion current average value Iavg and the maximum value Imax meet the following conditions: iavg is more than or equal to 95 and less than 105 or Imax is more than or equal to 100 and less than or equal to 110, the next modulation phase angle is reduced by 50.
The invention also provides a distortion pulse current self-adaptive dynamic adjustment sending device in power frequency communication, which comprises a voltage zero-crossing detection circuit, a power frequency voltage modulation circuit, a control unit, an uplink communicator and a memory, wherein the voltage zero-crossing detection circuit, the power frequency voltage modulation circuit, the uplink communicator and the memory are connected with the control unit, and the voltage zero-crossing detection circuit and the power frequency voltage modulation circuit are connected with a low-voltage power line.
Furthermore, the distortion pulse current sampling circuit comprises a phase current transformer, a low-pass filter circuit, an I/V conversion circuit, a differential to single-ended conversion circuit and a direct current bias superposition circuit, wherein the phase current transformer is connected with the low-pass filter circuit, the low-pass filter circuit is connected with the I/V conversion circuit, the I/V conversion circuit is connected with the differential to single-ended conversion circuit, the differential to single-ended conversion circuit is connected with the direct current bias superposition circuit, and the direct current bias superposition circuit is connected with an ADC input end of the control unit.
Furthermore, the phase current transformer is an external open type phase current transformer.
Furthermore, the external open-type phase current transformer adopts a transformer with the 200A specification, the 300A specification or the 400A specification.
The invention has the beneficial effects that:
under the condition that each time of complete modulation and the device can identify the coding information, the interval in which the average value Iavg and the maximum value Imax of the distortion pulse current fall is used for determining whether the modulation phase open angle value of the next complete modulation is adjusted or not, and finally the amplitude value of the distortion pulse current signal falls in the set safe interval.
A self-adaptive dynamic adjustment transmitting device for distorted pulse current in power frequency communication is provided with a power frequency voltage modulation transmitting circuit which is provided by a traditional transmitting device, and is also provided with a distorted pulse current signal sampling circuit which can sample and feed back a distorted pulse current signal generated by the power frequency voltage modulation transmitting circuit to a control unit, the distorted pulse current signal is processed and analyzed and calculated by the control unit, a power frequency voltage modulation phase angle is self-adaptively and dynamically adjusted according to the method disclosed by the invention, the amplitude value of the distorted pulse current signal is finally enabled to fall in a set safe safety interval, and the success rate of a receiving end identification device is ensured.
The method and the device enable the power frequency communication system to have self-learning capability, adjust the power frequency voltage modulation phase opening angle according to the power grid operating parameters and environmental changes, finally adaptively and dynamically adjust the distorted pulse current and send the distorted pulse current, and can ensure the safety of the power frequency voltage modulation circuit of the sending device and the identification success rate of the receiving device.
Drawings
FIG. 1 is a flow chart of an embodiment of the present invention.
Fig. 2 is a flowchart of step S101 in fig. 1.
Fig. 3 is a flowchart of step S103 in fig. 1.
Fig. 4 is a structural view of the embodiment of the present invention.
Fig. 5 is a block diagram of the distorted pulse current sampling circuit of fig. 4.
Fig. 6 is a circuit diagram of the distorted pulse current sampling circuit of fig. 4.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.
As shown in fig. 1, a method for adaptively and dynamically adjusting distorted pulse current in power frequency communication includes the following steps:
step S101: and modulating and coding the power frequency voltage signal.
As shown in fig. 2, in step S101, the modulating and encoding the power frequency voltage signal includes the following steps:
step S201: and identifying zero crossing point information in real time according to the power frequency voltage zero crossing detection circuit.
Step S202: and receiving a starting power frequency voltage modulation command of a waiting superior terminal, reading a current power frequency voltage modulation phase angle stored in a memory if the starting modulation command is received, and controlling a power frequency voltage modulation circuit to modulate so that an instantaneous distortion pulse current signal can be generated at a voltage zero-crossing point to complete power frequency voltage cycle modulation.
As a more optimized scheme, the power frequency voltage modulation phase angle ranges from 300 microseconds to 900 microseconds, and the default value for the first time is 600 microseconds.
Step S203: and sequentially modulating the power frequency voltage according to a certain modulation coding method until all the coded information which can represent the identification code or the device address is sent, thus completing one-time complete modulation. The primary power frequency voltage modulation can generate N distorted pulse current signals, and 10< N <100 as a more optimized scheme.
Step S102: and collecting the load current on the corresponding phase current circuit of the power frequency voltage modulation device.
And the load current on the phase current circuit is acquired through the current sampling circuit and the ADC module, and the current signal is converted into a digital signal. As a more optimized scheme, the number of sampling points of the current cycle can be set to 64 points, or 80 points, or 128 points, or 256 points, and the larger the number of sampling points is, the closer the digitized signal is to the original signal.
Step S103: and extracting and identifying the effective distortion pulse current signal and demodulating coded information.
As shown in fig. 3, in step S103, extracting the identification valid distortion pulse current signal and demodulating the encoded information includes the following steps:
step S301: according to the characteristic that power frequency voltage modulation utilizes voltage waveform zero-crossing region modulation, a detection time window is arranged near a voltage zero-crossing point, and original load current data in the corresponding time window are analyzed.
As a more optimized scheme, the detection time window includes N original sampling point data sampled before and after the voltage zero crossing point, N is set to be 4< N <15 according to the characteristic of the modulation circuit, the larger the N value is, the larger the calculation amount is, and the more the memory resources of the control unit are occupied.
Step S302: and calculating the amplitude of the pulse current signal in each current cycle detection time window. And calculating the amplitude of the calculated pulse current signal by adopting a time domain method or a frequency domain method.
Step S303: comparing the amplitude of the distorted pulse current signal extracted and calculated in each current cycle detection time window with a set threshold identification threshold, and if the amplitude is greater than the threshold identification threshold, judging the distorted pulse current signal as an effective distorted pulse current signal; and if the extracted and calculated amplitude of the distorted pulse current signal is smaller than the set threshold value, judging the distorted pulse current signal to be an invalid distorted pulse current signal.
Step S304: and demodulating each effective distortion pulse current signal according to a set coding rule, and identifying coded information.
Step S104: and adjusting the next power frequency voltage modulation phase angle according to the identified average value and the maximum value of the amplitude of the distorted pulse current signal.
If the correct coded information can be demodulated in step S103, the next phase angle adjustment of the power frequency voltage modulation is performed according to the following steps:
calculating the average value Iavg and the maximum value Imax of the amplitude values of a plurality of distorted pulse current signals generated by each modulation; wherein Iavg is the average value of the amplitude values of a plurality of distorted pulse current signals generated by each modulation, and the unit is ampere A; imax is the maximum amplitude value of a plurality of distorted pulse current signals generated by each modulation, and the unit is ampere A.
Adjusting the next power frequency voltage modulation phase angle according to the following strategy:
modulating at any time, and when the average value Iavg of the generated pulse distortion current meets 10< Iavg <55, stepping the phase angle for modulating at the next time by 150;
modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 55-65 of Iavg and 100 of Imax, stepping 120 the phase angle of the next modulation;
modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 65-75 of Iavg and 100 of Imax, stepping 80 the phase angle of the next modulation;
and (4) modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 80-85 Iavg and 100 Imax, stepping the phase angle by 50 in the next modulation.
And (4) modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 80-85 Iavg and 100 Imax, stepping the phase angle by 30 for the next modulation.
Modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet the conditions that the Iavg is more than or equal to 85 and less than or equal to 95 and the Imax is less than or equal to 100, the phase angle of the next modulation is not changed, and the phase angle of the previous modulation is still kept;
modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 105-Iavg or 110-Imax, reducing the phase angle of the next modulation by 100;
and (3) modulating at any time, when the generated pulse distortion current average value Iavg and the maximum value Imax meet the following conditions: iavg is more than or equal to 95 and less than 105 or Imax is more than or equal to 100 and less than or equal to 110, the next modulation phase angle is reduced by 50.
Step S105: and modulating and coding the power frequency voltage signal according to the adjusted power frequency voltage modulation phase angle.
As shown in fig. 4, the distortion pulse current adaptive dynamic adjustment transmitting apparatus in power frequency communication in the present embodiment includes a voltage zero-crossing detection circuit 401, a power frequency voltage modulation circuit 406, a distortion pulse current sampling circuit 405, a control unit 402, an uplink communicator 404, and a memory 403, where the voltage zero-crossing detection circuit 401, the power frequency voltage modulation circuit 406, the distortion pulse current sampling circuit 405, the uplink communicator 404, and the memory 403 are connected to the control unit 402, and the voltage zero-crossing detection circuit 401, the distortion pulse current sampling circuit 405, and the power frequency voltage modulation circuit 406 are connected to a low-voltage power line.
The control unit 402 is mainly used for controlling the power frequency voltage modulation circuit to generate distortion voltage and distortion pulse current signals according to a certain voltage phase angle near the power frequency voltage zero crossing point, the distortion pulse current signals are collected by the distortion pulse current sampling circuit and fed back to the control unit, the control unit calculates the amplitude of the distortion pulse current signals, whether the power frequency voltage modulation phase angle is adjusted or not is judged by calculating the amplitude of the distortion pulse current signals, and finally the amplitude of the distortion pulse current signals generated by modulation falls in a set reasonable safety interval. The voltage zero-crossing detection circuit 401 is mainly used for detecting the zero-crossing point of the power frequency voltage. The uplink communicator 404 includes a slave node HPLC carrier communication unit for uplink communication with a master node HPLC carrier, and an uplink RS485 communication unit for communication with other master devices. The memory 403 is used for storing the initial power frequency voltage modulation phase opening angle, relevant topology identification data and the like. The power frequency voltage modulation circuit 406 is used for modulating the power frequency voltage to generate a distorted pulse current signal. The power frequency voltage modulation circuit 406 mainly comprises a current limiting device, a switching tube and a switching tube driving circuit, wherein the current limiting device is used for controlling the magnitude of the generated distortion pulse current, and the switching tube driving circuit is used for driving the switching tube to be switched on and off. The distortion pulse current sampling circuit 405 is mainly responsible for sampling the distortion pulse current signal, and sends the acquired distortion pulse current signal to the internal ADC analog-to-digital converter of the control unit 402, and the control unit 402 calculates, analyzes and calculates the amplitude of the distortion pulse current.
As shown in fig. 5, the distortion pulse current sampling circuit includes a phase current transformer 501, a low-pass filter circuit 502, an I/V conversion circuit 503, a differential to single-ended circuit 504, and a dc offset superposition circuit 505, where the phase current transformer 501 is connected to the low-pass filter circuit 502, the low-pass filter circuit 502 is connected to the I/V conversion circuit 503, the I/V conversion circuit 503 is connected to the differential to single-ended circuit 504, the differential to single-ended circuit 504 is connected to the dc offset superposition circuit 505, and the dc offset superposition circuit 505 is connected to an ADC input 506 of the control unit. The phase current transformer is used for converting a large current signal into a small current signal; the low-pass filter is used for filtering high-frequency noise, the I/V conversion circuit is used for converting small current signals collected by the current transformer into small voltage signals, the difference-to-single-ended circuit is used for converting the difference small voltage signals sampled by the I/V conversion circuit into single-ended signals, the single-ended signals are processed by the direct-current bias superposition circuit to become single-ended signals with certain direct-current bias and suitable for processing by the control unit ADC, and the signals finally enter the internal ADC of the control unit. More preferably, the phase current transformer 501 is an external open-type phase current transformer. More preferably, the phase current transformer 501 is a transformer of 200A standard, 300A standard, or 400A standard.
Fig. 6 discloses a circuit diagram of the distorted pulse current sampling circuit in fig. 4, and an LC low-pass filter is composed of inductors L1 and L2, and capacitors C3 and C5, wherein the inductors L1 and L2 can be selected from inductors or magnetic beads. More preferably, the inductors L1 and L2 are chip magnetic beads of the type CBG201209U102T, and the capacitors C3 and C5 have the capacitance value of 1000 pf. The I/V conversion circuit is composed of two differential sampling resistors R1 and R9, and preferably, the resistance values of R1 and R9 are both 2 omega. The differential-to-single-ended circuit is composed of resistors R2, R4, R6 and R10, a capacitor C1 and an operational amplifier U1B, wherein the capacitor C1 is used for phase compensation, oscillation is prevented, and high-frequency noise is suppressed. More preferably, the resistance of the two resistors R2 and R10 is 30k Ω, the resistance of the two resistors R4 and R6 is 10k Ω, and the capacitance of the capacitor C1 is 100 pf. The resistors R3, R5 and R8, the capacitor C2 and the operational amplifier U1C form a direct current bias superposition resistor which is used for superposing the single-end voltage signal on the direct current bias of 1.6V so that the peak-to-peak value of the single-end voltage signal is within the sampling range of the ADC converter in the control unit, and the capacitor C2 is used for phase compensation, prevents oscillation and inhibits high-frequency noise. The output signal of the operational amplifier U1C is sent to the ADC input ADCIN of the control unit through the resistor R7, and the capacitor C4 is used for filtering high frequency noise in the output signal. More preferably, the resistances of the two resistors R3, R5 and R8 are 10k Ω, and the capacitance of the capacitor C2 is 100 pf.
More preferably, the control unit adopts STM32FX series single-chip microcomputer.
The embodiment of the invention can carry out sequence adjustment, combination and deletion according to actual needs.
The embodiments describe the present invention in detail, and the specific embodiments are applied to illustrate the principle and the implementation of the present invention, and the above embodiments are only used to help understand the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
Claims (10)
1. A distortion pulse current self-adaptive dynamic adjustment method in power frequency communication is characterized by comprising the following steps:
modulating and coding the power frequency voltage signal;
collecting load current on a corresponding phase current circuit of the power frequency voltage modulation device;
extracting and identifying effective distortion pulse current signals and demodulating coded information;
adjusting the next power frequency voltage modulation phase angle according to the identified average value and the maximum value of the amplitude of the distorted pulse current signal;
and modulating and coding the power frequency voltage signal according to the adjusted power frequency voltage modulation phase angle.
2. The method for adaptively and dynamically adjusting the distorted pulse current in power frequency communication according to claim 1, wherein the step of modulating and encoding the power frequency voltage signal comprises the following steps:
identifying zero crossing point information in real time according to a power frequency voltage zero crossing detection circuit;
receiving a starting power frequency voltage modulation command of a waiting superior terminal, and if the starting modulation command is received, reading a current power frequency voltage modulation phase angle stored in a memory and controlling a power frequency voltage modulation circuit to modulate;
and sequentially modulating the power frequency voltage according to a certain modulation coding method until all coding information which can represent the identification code or the device address is sent.
3. The method for adaptively and dynamically adjusting the distorted pulse current in power frequency communication according to claim 1 or claim 2, wherein the power frequency voltage modulation phase angle ranges from 300 microseconds to 900 microseconds.
4. The method for adaptively and dynamically adjusting the distortion pulse current in power frequency communication according to claim 1 or claim 2, wherein the power frequency voltage modulation phase angle is first default to 600 microseconds in a set time period.
5. The method of claim 1, wherein the step of extracting and identifying the valid distorted pulse current signal and demodulating the encoded information comprises the steps of:
according to the characteristic that power frequency voltage modulation utilizes voltage waveform zero-crossing region modulation, a detection time window is arranged near a voltage zero-crossing point, and original load current data in the corresponding time window are analyzed;
calculating the amplitude of the pulse current signal in each current cycle detection time window;
comparing the amplitude of the distorted pulse current signal extracted and calculated in each current cycle detection time window with a set threshold identification threshold, and if the amplitude is greater than the threshold identification threshold, judging the distorted pulse current signal as an effective distorted pulse current signal; if the amplitude of the extracted and calculated distortion pulse current signal is smaller than a set threshold value, judging the distortion pulse current signal to be an invalid distortion pulse current signal;
and demodulating each effective distortion pulse current signal according to a set coding rule, and identifying coded information.
6. The method for adaptively and dynamically adjusting distorted pulse current in power frequency communication according to claim 1, wherein in the step of adjusting the next power frequency voltage modulation phase angle according to the identified average value and maximum value of the amplitude of the distorted pulse current signal, the step of adjusting the next power frequency voltage modulation phase angle comprises:
calculating the average value Iavg and the maximum value Imax of the amplitude values of a plurality of distorted pulse current signals generated by each modulation;
adjusting the next power frequency voltage modulation phase angle according to the following strategy:
modulating at any time, and when the average value Iavg of the generated pulse distortion current meets 10< Iavg <55, stepping the phase angle for modulating at the next time by 150;
modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 55-65 of Iavg and 100 of Imax, stepping 120 the phase angle of the next modulation;
modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 65-75 of Iavg and 100 of Imax, stepping 80 the phase angle of the next modulation;
and (4) modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 80-85 Iavg and 100 Imax, stepping the phase angle by 50 in the next modulation.
And (4) modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 80-85 Iavg and 100 Imax, stepping the phase angle by 30 for the next modulation.
Modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet the conditions that the Iavg is more than or equal to 85 and less than or equal to 95 and the Imax is less than or equal to 100, the phase angle of the next modulation is not changed, and the phase angle of the previous modulation is still kept;
modulating at any time, and when the average value Iavg and the maximum value Imax of the generated pulse distortion current meet 105-Iavg or 110-Imax, reducing the phase angle of the next modulation by 100;
and (3) modulating at any time, when the generated pulse distortion current average value Iavg and the maximum value Imax meet the following conditions: iavg is more than or equal to 95 and less than 105 or Imax is more than or equal to 100 and less than or equal to 110, the next modulation phase angle is reduced by 50.
7. A distortion pulse current self-adaptive dynamic adjustment sending device in power frequency communication comprises a voltage zero-crossing detection circuit, a power frequency voltage modulation circuit, a control unit, an uplink communicator and a memory, wherein the voltage zero-crossing detection circuit, the power frequency voltage modulation circuit, the uplink communicator and the memory are connected with the control unit, and the voltage zero-crossing detection circuit and the power frequency voltage modulation circuit are connected with a low-voltage power line.
8. The adaptive dynamic adjustment transmitting device for distorted pulse current in power frequency communication according to claim 7, wherein the distorted pulse current sampling circuit comprises a phase current transformer, a low-pass filter circuit, an I/V conversion circuit, a differential to single-ended circuit, and a dc offset superposition circuit, the phase current transformer is connected to the low-pass filter circuit, the low-pass filter circuit is connected to the I/V conversion circuit, the I/V conversion circuit is connected to the differential to single-ended circuit, the differential to single-ended circuit is connected to the dc offset superposition circuit, and the dc offset superposition circuit is connected to an ADC input terminal of the control unit.
9. The adaptive dynamic distortion pulse current adjustment sending apparatus in power frequency communication according to claim 8, wherein the phase current transformer is an external open-type phase current transformer.
10. The adaptive dynamic adjustment transmitting device for distorted pulse current in power frequency communication according to claim 9, wherein the external open-type phase current transformer is 200A-standard or 300A-standard or 400A-standard transformer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110482979.0A CN113225280A (en) | 2021-04-30 | 2021-04-30 | Distortion pulse current self-adaptive dynamic adjustment method in power frequency communication and self-adaptive dynamic adjustment sending device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110482979.0A CN113225280A (en) | 2021-04-30 | 2021-04-30 | Distortion pulse current self-adaptive dynamic adjustment method in power frequency communication and self-adaptive dynamic adjustment sending device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113225280A true CN113225280A (en) | 2021-08-06 |
Family
ID=77090567
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110482979.0A Pending CN113225280A (en) | 2021-04-30 | 2021-04-30 | Distortion pulse current self-adaptive dynamic adjustment method in power frequency communication and self-adaptive dynamic adjustment sending device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113225280A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114629760A (en) * | 2022-04-07 | 2022-06-14 | 青岛鼎信通讯股份有限公司 | Low-voltage transformer area characteristic current communication method based on frequency domain modulation |
| CN115410359A (en) * | 2022-07-18 | 2022-11-29 | 北京三圣凯瑞科技有限公司 | Power frequency distortion communication method and device |
| CN116861203A (en) * | 2023-09-05 | 2023-10-10 | 青岛鼎信通讯科技有限公司 | Microcurrent signal identification method based on single-frequency signal |
-
2021
- 2021-04-30 CN CN202110482979.0A patent/CN113225280A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114629760A (en) * | 2022-04-07 | 2022-06-14 | 青岛鼎信通讯股份有限公司 | Low-voltage transformer area characteristic current communication method based on frequency domain modulation |
| CN114629760B (en) * | 2022-04-07 | 2023-07-07 | 青岛鼎信通讯股份有限公司 | Low-voltage station area characteristic current communication method based on frequency domain modulation |
| CN115410359A (en) * | 2022-07-18 | 2022-11-29 | 北京三圣凯瑞科技有限公司 | Power frequency distortion communication method and device |
| CN116861203A (en) * | 2023-09-05 | 2023-10-10 | 青岛鼎信通讯科技有限公司 | Microcurrent signal identification method based on single-frequency signal |
| CN116861203B (en) * | 2023-09-05 | 2024-01-09 | 青岛鼎信通讯科技有限公司 | Microcurrent signal identification method based on single-frequency signal |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113225280A (en) | Distortion pulse current self-adaptive dynamic adjustment method in power frequency communication and self-adaptive dynamic adjustment sending device | |
| US4300126A (en) | Method and apparatus, for power line communications using zero crossing load interruption | |
| WO2002043268B1 (en) | Power line communication system | |
| CN101826893B (en) | Intelligent ammeter for carrier communication by utilizing power line and working method thereof | |
| CN111600380A (en) | Variable load and constant current detection-based household variable relation identification method | |
| CN104917547A (en) | TPLC based power line power frequency communication system | |
| US20120027062A1 (en) | Apparatuses and methods for setting an adaptive frequency band for power line communciation | |
| CN103916207A (en) | Active device and method for interfering multi-frequency-band power line communication | |
| CN108267638B (en) | Power frequency synchronous communication signal detection device, system and method based on power frequency distortion | |
| CN109039378B (en) | Method for realizing self-adaptive switching of communication frequency bands of G3-PLC network | |
| CN103516395A (en) | Adaptive power line carrier communication device and method | |
| CN111103498B (en) | Low-voltage transformer area line-change user relationship identification system and method | |
| CN104218975A (en) | Power line carrier communication method and information transmitting device | |
| CN114325027A (en) | Household variable relation recognition device, method, terminal and topological structure recognition system | |
| CN215420332U (en) | Distortion pulse current self-adaptation dynamic adjustment transmitting device in power frequency communication | |
| CN104464252A (en) | Intelligent electricity meter using power line as communication signal carrier and working method thereof | |
| EP3569985B1 (en) | An electricity meter and an adaptor module therefor | |
| CN204761431U (en) | Power line power frequency communication system based on TPLC | |
| CN103475391B (en) | Power-line carrier communication method | |
| CN204836167U (en) | Carrier communication module | |
| CN210690678U (en) | Detection circuit and multi-branch identification device | |
| Stefanutti et al. | Communication on power lines using frequency and duty-cycle modulation in digitally controlled dc-dc converters | |
| CN202872827U (en) | Self-adaptive power line carrier communication apparatus | |
| CN106370914B (en) | Zero-sequence current carrier signal generating device and signal transmission method | |
| Ostertag et al. | High data rate, medium voltage powerline communications for hybrid DA/DSM |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |