A method for adaptive dynamic adjustment of distorted pulse current in power frequency communication

Abstract

The present invention discloses a method and device for adaptively and dynamically adjusting distorted pulse current in power frequency communication. The method comprises the following steps: modulation and coding of power frequency voltage signals; collecting load current on the corresponding phase current line of the power frequency voltage modulation device; extracting and identifying effective distorted pulse current signals and demodulating the coding information; adjusting the next power frequency voltage modulation phase angle according to the identified average and maximum amplitude values ​​of the distorted pulse current signals; and performing power frequency voltage signal modulation and coding 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 distorted pulse current sampling circuit, a control unit, an uplink communicator, and a memory. The present invention can adjust the power frequency voltage modulation phase opening angle according to power grid operation parameters and environmental changes, and adaptively and dynamically adjust the distorted pulse current to ensure the safety of the power frequency voltage modulation circuit of the sending device and the recognition success rate of the receiving device.

Description

Technical Field

[0001] The invention relates to the technical field of instruments and meters, and in particular to a method for adaptively and dynamically adjusting distorted pulse current in power frequency communication. Background Art

[0002] At present, one of the key tasks of the power consumption information collection system and the low-voltage distribution network system is to realize the automatic identification of the household-to-transformer relationship and the physical topological relationship of the substation in the low-voltage distribution network. Through the accurate household-to-transformer relationship of the substation, the low success rate of substation meter reading and inaccurate calculation of substation line loss caused by inaccurate substation ownership can be discovered in time. Substation household-to-transformer relationship and topological identification are generally realized by power frequency communication technology. The main principle of power frequency communication technology is to use the zero-crossing modulation method of the power frequency voltage fundamental wave, and use the weak distortion of the modulated voltage or current waveform near the zero-crossing point to carry information. Information transmission is realized by using the relative change and invariance of the voltage or current in adjacent cycles.

[0003] The entire power frequency communication system includes a power frequency voltage modulation device and a corresponding distorted pulse current receiving and identifying device. The power frequency voltage modulation and sending device is generally installed on the end user side such as the meter box and branch box of the low-voltage distribution station area, and the distorted pulse current receiving and identifying device is generally installed on the branch box of the low-voltage distribution station area and the low-voltage side of the distribution transformer. Its main working process is that the power frequency voltage modulation and sending device controls the switch tube to be turned on at a certain phase angle before the power frequency voltage passes through zero, and generates an instantaneous distorted pulse current signal on the low-voltage distribution line at the corresponding zero-crossing moment. This distorted pulse current signal will be superimposed on the load current at the voltage zero-crossing moment, and will be transmitted to the transformer side of the distribution station area along the power line connected to the modulation device. A distorted pulse current receiving device is installed at the location of the transformer. The distorted pulse current receiving device collects and demodulates the distorted pulse current signal, thus completing the identification of a distorted pulse current signal. According to a certain modulation and coding method, the power frequency voltage is modulated multiple times at the zero-crossing point continuously, which will generate multiple distorted pulse current signals. The identification end can complete a communication by identifying and demodulating this signal. The modulation is performed before the zero-crossing point of the power frequency voltage waveform. At this time, the energy required for modulation is minimal, and the impact on the power grid and the voltage and current distortion caused during the modulation process can be controlled within a reasonable range. The signal transmitted from the power frequency voltage modulation transmitter to the distorted pulse current receiving and identifying device is called the uplink modulation signal, which uses the current fundamental waveform to carry the modulation information.

[0004] The existing power frequency voltage modulation is composed of a current limiting device, a switch tube and a switch tube driving circuit. The current limiting device is used to control the size of the distorted pulse current generated, and the switch tube driving circuit is used to drive the switch tube to open and close. The current limiting device uses an inductor or a resistor, the switch tube uses a switch device such as a thyristor, a MOS tube and an IGBT, the switch tube driving circuit uses a pulse transformer and a thyristor optocoupler device, and the control unit can use an ordinary single-chip microcomputer or a microcontroller. The power frequency voltage modulation and sending device only has a power frequency voltage modulation circuit. Since there is no feedback loop, the sending device itself cannot know the size of the distorted pulse current signal generated by the modulated power frequency voltage. Therefore, the distorted pulse current sending device uses a fixed phase angle to modulate the power frequency voltage signal to generate a distorted pulse current signal.

[0005] However, the modulation and transmission device based on the fixed phase angle modulation method has the following problems:

[0006] (1) Fragile transmission device

[0007] The power grid operating environment is complex, and the line impedance varies. The distorted pulse current signals generated by the same phase-angle modulated power frequency voltage in different application environments vary in size. If the phase angle of the power frequency voltage modulation is too large or too small, it will affect the size of the distorted pulse current signal generated. If the distorted pulse current generated is too large, it can easily damage the switch tube of the transmitting device, causing damage to the device or false tripping of the nearby switch.

[0008] (2) The inability to dynamically adjust the size of the distorted pulse current signal adaptively results in a low recognition success rate at the receiving end

[0009] If the distorted pulse current signal is too large, it will damage the switch tube of the transmitting device. However, if it is too small, the identification device at the receiving end may not recognize it or may misidentify it, resulting in the distorted pulse current signal recognition rate at the receiving end being too low or not being able to be recognized at all. Summary of the invention

[0010] The technical problem to be solved by the present invention is to provide a method and a sending device for adaptively dynamically adjusting the distorted pulse current signal in industrial frequency communication, which can dynamically adjust the amplitude of the distorted pulse current signal according to the actual conditions of different substation environments, and ensure that the amplitude of the distorted pulse current signal falls within a set reasonable safety range, thereby preventing the distorted pulse current from being too large to damage the sending device or cause the switch to trip incorrectly, and preventing the distorted pulse current from being too small to cause the distorted pulse current signal recognition rate at the receiving end to be too low or unable to be recognized at all.

[0011] In order to solve the above technical problems, the present invention provides a method for adaptively and dynamically adjusting distorted pulse current in power frequency communication, comprising the following steps:

[0012] Power frequency voltage signal modulation coding;

[0013] Collect the load current on the corresponding phase current line of the power frequency voltage modulation device;

[0014] Extract and identify the effective distorted pulse current signal and demodulate the encoded information;

[0015] Adjust the next power frequency voltage modulation phase angle according to the average value and maximum value of the identified distorted pulse current signal amplitude;

[0016] Perform power frequency voltage signal modulation encoding according to the adjusted power frequency voltage modulation phase angle.

[0017] In the step of adjusting the next power frequency voltage modulation phase angle according to the average value and maximum value of the identified distorted pulse current signal amplitude, the next power frequency voltage modulation phase angle adjustment step includes:

[0018] Calculate the average value Iavg and maximum value Imax of the amplitudes of multiple distorted pulse current signals generated by each modulation; where Iavg is the average value of the amplitudes of multiple distorted pulse current signals generated by each modulation, with the unit of ampere A; Imax is the maximum value of the amplitudes of multiple distorted pulse current signals generated by each modulation, with the unit of ampere A;

[0019] Adjust the next power frequency voltage modulation phase angle according to the following strategy:

[0020] For any modulation, when the average value Iavg of the generated pulse distorted current satisfies 10 < Iavg < 55, the next modulation phase angle steps 2.7 degrees;

[0021] For any modulation, when the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 55 ≤ Iavg < 65 and Imax ≤ 100, the next modulation phase angle steps 2.16 degrees;

[0022] For any modulation, when the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 65 ≤ Iavg < 75 and Imax ≤ 100, the next modulation phase angle steps 1.44 degrees;

[0023] For any modulation, when the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 80 ≤ Iavg < 85 and Imax ≤ 100, the next modulation phase angle steps 0.9 degrees;

[0024] For any modulation, when the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 80 ≤ Iavg < 85 and Imax ≤ 100, the next modulation phase angle steps 0.54 degrees;

[0025] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy 85 ≤ Iavg < 95 and Imax ≤ 100, the phase angle of the next modulation remains unchanged and remains the same as the phase angle of the previous modulation.

[0026] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy 105 ≤ Iavg or 110 < Imax, the phase angle of the next modulation is reduced by 1.8 degrees.

[0027] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy: 95 ≤ Iavg < 105 or 100 < Imax ≤ 110, the phase angle of the next modulation is reduced by 0.9 degrees.

[0028] Furthermore, the steps of modulating and encoding the power frequency voltage signal include the following steps:

[0029] Real-time identify the zero-crossing point information according to the power frequency voltage zero-crossing detection circuit.

[0030] Receive and wait for the start power frequency voltage modulation command from the upper-level terminal. If the start modulation command is received, read the current power frequency voltage modulation phase angle stored in the memory and control the power frequency voltage modulation circuit to perform modulation.

[0031] Modulate the power frequency voltage in sequence according to a certain modulation and encoding method until all the encoding information representing the identification code or device address is sent.

[0032] Furthermore, the value range of the power frequency voltage modulation phase angle is from 5.4 degrees to 16.2 degrees.

[0033] Furthermore, within the set time period, the power frequency voltage modulation phase angle is initially defaulted to 10.8 degrees.

[0034] Furthermore, the steps of extracting the effective distortion pulse current signal and demodulating the encoding information include the following steps:

[0035] According to the characteristic of modulating using the zero-crossing region of the voltage waveform in the power frequency voltage modulation, set a detection time window near the voltage zero-crossing point and analyze the original load current data within the corresponding time window.

[0036] Calculate the amplitude of the pulse current signal within each current cycle detection time window.

[0037] The amplitude of the distorted pulse current signal extracted and calculated within each current cycle detection time window is compared with the set threshold recognition threshold. If it is greater than the threshold recognition threshold, the distorted pulse current signal is judged as a valid distorted pulse current signal; if the amplitude of the distorted pulse current signal extracted and calculated is less than the set threshold, it is judged as an invalid distorted pulse current signal;

[0038] Each effective distorted pulse current signal is demodulated according to the set coding rule to identify the coding information.

[0039] The present invention also provides a device for adaptively and dynamically adjusting the sending of distorted pulse current in industrial frequency communication, comprising a voltage zero-crossing detection circuit, an industrial frequency voltage modulation circuit, a control unit, an uplink communicator, and a memory, wherein the voltage zero-crossing detection circuit, the industrial frequency voltage modulation circuit, the uplink communicator, and the memory are connected to the control unit, and the voltage zero-crossing detection circuit and the industrial frequency voltage modulation circuit are connected to a low-voltage power line. The device is characterized in that it also includes a distorted pulse current sampling circuit, and the distorted pulse current sampling circuit is respectively connected to the control unit and the low-voltage power line.

[0040] Furthermore, the distorted pulse current sampling circuit includes a phase current transformer, a low-pass filter circuit, an I / V conversion circuit, a differential-to-single-ended circuit, and a DC bias 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 bias superposition circuit, and the DC bias superposition circuit is connected to the ADC input of the control unit.

[0041] Furthermore, the phase current transformer is an external open-type phase current transformer.

[0042] Furthermore, the external open-type phase current transformer adopts a transformer with a specification of 200A, 300A or 400A.

[0043] The beneficial effects of the present invention are:

[0044] A method for adaptive dynamic control of power frequency distorted pulse current size is proposed. The distorted pulse current size is collected and calculated in real time. Under the condition that each complete modulation is performed and the device can identify its coded information, the modulation phase opening angle value of the next complete modulation is adjusted according to the interval in which the average value Iavg and the maximum value Imax of the distorted pulse current fall, so that the amplitude of the distorted pulse current signal finally falls within the set safety interval.

[0045] A transmitting device for adaptively and dynamically adjusting distorted pulse current in industrial frequency communication, in addition to the industrial frequency voltage modulation transmitting circuit of a traditional transmitting device, is also provided with a distorted pulse current signal sampling circuit, which can sample and feed back the distorted pulse current signal generated by the industrial frequency voltage modulation transmitting circuit to a control unit, which processes, analyzes and calculates the distorted pulse current, and adaptively and dynamically adjusts the industrial frequency voltage modulation phase angle according to the method disclosed in the present invention, ultimately making the amplitude of the distorted pulse current signal fall within a set safety range and ensuring the success rate of the receiving end identification device.

[0046] The method and device enable the industrial frequency communication system to have self-learning ability, and can adjust the industrial frequency voltage modulation phase opening angle according to the power grid operating parameters and environmental changes, and finally adaptively and dynamically adjust the size of the distorted pulse current and send it, which can ensure the safety of the industrial frequency voltage modulation circuit of the sending device and the recognition success rate of the receiving device. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a flow chart of an embodiment of the present invention.

[0048] Figure 2 yes Figure 1 Flowchart of step S101 in FIG.

[0049] Figure 3 yes Figure 1 Flowchart of step S103 in FIG.

[0050] Figure 4 It is a structural diagram of an embodiment of the present invention.

[0051] Figure 5 yes Figure 4 Structural diagram of the medium distorted pulse current sampling circuit.

[0052] Figure 6 yes Figure 4 Circuit diagram of the distorted pulse current sampling circuit. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0055] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0056] like Figure 1 As shown, a method for adaptively and dynamically adjusting distorted pulse current in power frequency communication includes the following steps:

[0057] Step S101: Modulation and encoding of the power frequency voltage signal.

[0058] like Figure 2 As shown, in step S101, modulating and encoding the power frequency voltage signal includes the following steps:

[0059] Step S201: identifying zero-crossing point information in real time according to the power frequency voltage zero-crossing detection circuit.

[0060] Step S202: Receive and wait for the start-up power frequency voltage modulation command from the upper terminal. If the start-up modulation command is received, read the current power frequency voltage modulation phase angle stored in the memory, and control the power frequency voltage modulation circuit to perform modulation. In this way, an instantaneous distorted pulse current signal will be generated at the voltage zero point, completing a power frequency voltage cycle modulation.

[0061] As a more optimized solution, the power frequency voltage modulation phase angle ranges from 5.4 degrees to 16.2 degrees, and the initial default value is 10.8 degrees.

[0062] Step S203: Modulate the power frequency voltage in sequence according to a certain modulation coding method until all the coded information representing the identification code or device address is sent, that is, a complete modulation is completed. One power frequency voltage modulation will generate N distorted pulse current signals. As a more optimized solution, 10 <N<100。

[0063] Step S102: collecting the load current on the corresponding phase current circuit of the power frequency voltage modulation device.

[0064] The load current on the phase current line is collected through the current sampling circuit and the ADC module and the current signal is converted into a digital signal. As a more optimized solution, the number of current cycle sampling points can be set to 64 points, 80 points, 128 points or 256 points. The more sampling points there are, the closer the digitized signal is to the original signal.

[0065] Step S103: Extract and identify the effective distorted pulse current signal and demodulate the encoded information.

[0066] As Figure 3 shown, in Step S103, extracting and identifying the effective distorted pulse current signal and demodulating the encoded information includes the following steps:

[0067] Step S301: According to the power frequency voltage modulation and using the characteristic of voltage waveform zero-crossing region modulation, set a detection time window near the voltage zero-crossing point and analyze the original load current data within the corresponding time window.

[0068] As a more optimized solution, the detection time window includes the data of N original sampling points sampled before and after the voltage zero-crossing point. According to the characteristics of the modulation circuit, N is set to 4 < N < 15. The larger the value of N, the greater the calculation amount and the more memory resources of the control unit are occupied.

[0069] Step S302: Calculate the amplitude of the pulse current signal within each current cycle detection time window. Use the time domain method or the frequency domain method to calculate the amplitude of the calculated pulse current signal.

[0070] Step S303: Compare the amplitude of the distorted pulse current signal extracted and calculated within each current cycle detection time window with the set threshold identification threshold. If it is greater than the threshold identification threshold, the distorted pulse current signal of this time is judged as an effective distorted pulse current signal; if the amplitude of the distorted pulse current signal extracted and calculated is less than the set threshold, it is judged as an ineffective distorted pulse current signal.

[0071] Step S304: Demodulate each effective distorted pulse current signal according to the set coding rule and identify the encoded information.

[0072] Step S104: Adjust the phase angle of the next power frequency voltage modulation according to the average value and the maximum value of the identified distorted pulse current signal amplitude.

[0073] If the correct encoded information can be demodulated in Step S103, the adjustment of the phase angle of the next power frequency voltage modulation is carried out according to the following steps:

[0074] Calculate the average value Iavg and the maximum value Imax of the amplitudes of the multiple distorted pulse current signals generated by each modulation; where Iavg is the average value of the amplitudes of the multiple distorted pulse current signals generated by each modulation, with the unit of ampere A; Imax is the maximum value of the amplitudes of the multiple distorted pulse current signals generated by each modulation, with the unit of ampere A.

[0075] Adjust the phase angle of the next power frequency voltage modulation according to the following strategy:

[0076] For any modulation, when the average value Iavg of the generated pulse distortion current satisfies 10 < Iavg < 55, the phase angle of the next modulation steps 2.7 degrees;

[0077] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy 55 ≤ Iavg < 65 and Imax ≤ 100, the phase angle of the next modulation steps 2.16 degrees;

[0078] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy 65 ≤ Iavg < 75 and Imax ≤ 100, the phase angle of the next modulation steps 1.44 degrees;

[0079] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy 80 ≤ Iavg < 85 and Imax ≤ 100, the phase angle of the next modulation steps 0.9 degrees.

[0080] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy 80 ≤ Iavg < 85 and Imax ≤ 100, the phase angle of the next modulation steps 0.54 degrees.

[0081] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy 85 ≤ Iavg < 95 and Imax ≤ 100, the phase angle of the next modulation remains unchanged and still maintains the phase angle of the previous modulation;

[0082] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy 105 ≤ Iavg or 110 < Imax, the phase angle of the next modulation decreases by 1.8 degrees;

[0083] For any modulation, when the average value Iavg and the maximum value Imax of the generated pulse distortion current satisfy: 95 ≤ Iavg < 105 or 100 < Imax ≤ 110, the phase angle of the next modulation decreases by 0.9 degrees.

[0084] Step S105: Modulate and encode the power frequency voltage signal according to the adjusted power frequency voltage modulation phase angle.

[0085] Such as Figure 4As shown, the distorted pulse current adaptive dynamic adjustment sending device in the industrial frequency communication in this embodiment includes a voltage zero-crossing detection circuit 401, an industrial frequency voltage modulation circuit 406, a distorted pulse current sampling circuit 405, a control unit 402, an uplink communicator 404, and a memory 403. The voltage zero-crossing detection circuit 401, the industrial frequency voltage modulation circuit 406, the distorted 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 distorted pulse current sampling circuit 405, and the industrial frequency voltage modulation circuit 406 are connected to the low-voltage power line.

[0086] The control unit 402 is mainly used to control the power frequency voltage modulation circuit to generate distorted voltage and distorted pulse current signal near the power frequency voltage zero crossing point according to a certain voltage phase angle. The distorted pulse current signal is collected by the distorted pulse current sampling circuit and fed back to the control unit. The control unit calculates the distorted pulse current signal amplitude, and determines whether to adjust the power frequency voltage modulation phase angle by calculating the distorted pulse current signal amplitude. The ultimate goal is to make the distorted pulse current signal amplitude generated by the modulation fall within the set reasonable safety interval. The voltage zero crossing detection circuit 401 is mainly used to detect the zero crossing point of the power frequency voltage. The uplink communicator 404 includes a slave node HPLC carrier communication unit and an uplink RS485 communication unit. The HPLC carrier communication unit is used for uplink communication with the master node HPLC carrier, and the uplink RS485 communication unit is used to communicate with other main devices. The memory 403 is used to store the initial power frequency voltage modulation phase opening angle and related topology identification data. The power frequency voltage modulation circuit 406 is used to modulate the power frequency voltage to generate a distorted pulse current signal. The power frequency voltage modulation circuit 406 is mainly composed of a current limiting device, a switch tube and a switch tube driving circuit. The current limiting device is used to control the size of the distorted pulse current generated, and the switch tube driving circuit is used to drive the switch tube to be turned on and off. The distorted pulse current sampling circuit 405 is mainly responsible for sampling the distorted pulse current signal, and sends the collected distorted pulse current signal to the internal ADC analog-to-digital converter of the control unit 402, and the control unit 402 operates, analyzes and calculates the distorted pulse current amplitude.

[0087] like Figure 5As shown, the distorted 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 bias superposition circuit 505. 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 bias superposition circuit 505, and the DC bias superposition circuit 505 is connected to the ADC input terminal 506 of the control unit. The phase current transformer is used to convert a large current signal into a small current signal; the low-pass filter is used to filter out high-frequency noise, the I / V conversion circuit is used to convert the small current signal collected by the current transformer into a small voltage signal, and the differential to single-ended circuit is used to convert the differential small voltage signal sampled by the I / V conversion circuit into a single-ended signal. The single-ended signal is processed by the DC bias superposition circuit and becomes a single-ended signal with a certain DC bias suitable for the control unit ADC to process. The signal finally enters the internal ADC analog-to-digital converter of the control unit. As a more preferred solution, the phase current transformer 501 is an external open-type phase current transformer. As a more preferred solution, the phase current transformer 501 adopts a transformer with a specification of 200A, 300A or 400A.

[0088] Figure 6 Public Figure 4 The circuit diagram of the distorted pulse current sampling circuit is composed of an LC low-pass filter composed of inductors L1, L2, capacitors C3 and C5, wherein inductors L1 and L2 can be selected as inductors or magnetic beads. As a more preferred solution, inductors L1 and L2 use chip magnetic beads of model CBG201209U102T, and the capacitance of capacitors C3 and C5 is 1000pf. The I / V conversion circuit is composed of two differential sampling resistors R1 and R9. As a more preferred solution, the resistance values ​​of R1 and R9 are both 2Ω. The differential to single-ended circuit is composed of resistors R2, R4, R6, R10, capacitor C1 and operational amplifier U1B, wherein capacitor C1 is used for phase compensation, oscillation prevention, and suppression of high-frequency noise. As a more preferred solution, the resistance values ​​of the two resistors R2 and R10 are 30kΩ, the resistance values ​​of the two resistors R4 and R6 are 10kΩ, and the capacitance value of capacitor C1 is 100pf. The DC bias superposition resistor is composed of resistors R3, R5, R8, capacitor C2 and operational amplifier U1C, which is used to superimpose the single-ended voltage signal on the 1.6V DC bias so that the peak-to-peak value of the single-ended voltage signal falls within the sampling range of the ADC converter inside the control unit. Capacitor C2 is used for phase compensation, preventing oscillation and suppressing high-frequency noise. The output signal of operational amplifier U1C is sent to the ADC input terminal ADCIN of the control unit through resistor R7, and capacitor C4 is used to filter out high-frequency noise in the output signal. As a more preferred solution, the resistance values ​​of the two resistors R3, R5 and R8 are 10kΩ, and the capacitance value of capacitor C2 is 100pf.

[0089] As a more preferred solution, the control unit adopts an STM32FX series microcontroller.

[0090] The embodiments of the present invention can be adjusted, merged and deleted in sequence according to actual needs.

[0091] The embodiments have been described in detail. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The above embodiments are only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for adaptively and dynamically adjusting distorted pulse current in power frequency communication, characterized in that: It includes the following steps: Power frequency voltage signal modulation coding; Collect the load current on the corresponding phase current line of the power frequency voltage modulation device; Extract and identify the effective distorted pulse current signal and demodulate the coding information; Adjust the phase angle of the next power frequency voltage modulation according to the average value and maximum value of the identified distorted pulse current signal amplitude; Perform power frequency voltage signal modulation coding according to the adjusted phase angle of the power frequency voltage modulation; In the step of adjusting the phase angle of the next power frequency voltage modulation according to the average value and maximum value of the identified distorted pulse current signal amplitude, the step of adjusting the phase angle of the next power frequency voltage modulation includes: Calculate the average value Iavg and maximum value Imax of the amplitudes of multiple distorted pulse current signals generated by each modulation; where Iavg is the average value of the amplitudes of multiple distorted pulse current signals generated by each modulation, with the unit of ampere A; Imax is the maximum value of the amplitudes of multiple distorted pulse current signals generated by each modulation, with the unit of ampere A; Adjust the phase angle of the next power frequency voltage modulation according to the following strategy: When the average value Iavg of the generated pulse distorted current satisfies 10 < Iavg < 55, the phase angle of the next modulation steps 2.7 degrees; When the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 55 ≤ Iavg < 65 and Imax ≤ 100, the phase angle of the next modulation steps 2.16 degrees; When the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 65 ≤ Iavg < 75 and Imax ≤ 100, the phase angle of the next modulation steps 1.44 degrees; When the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 80 ≤ Iavg < 85 and Imax ≤ 100, the phase angle of the next modulation steps 0.9 degrees; When the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 80 ≤ Iavg < 85 and Imax ≤ 100, the phase angle of the next modulation steps 0.54 degrees; When the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 85 ≤ Iavg < 95 and Imax ≤ 100, the phase angle of the next modulation remains unchanged and still maintains the phase angle of the previous modulation; When the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy 105 ≤ Iavg or 110 < Imax, the phase angle of the next modulation decreases by 1.8 degrees; When the average value Iavg and maximum value Imax of the generated pulse distorted current satisfy: 95 ≤ Iavg < 105 or 100 < Imax ≤ 110, the phase angle of the next modulation decreases by 0.9 degrees.

2. The method for adaptively adjusting distorted pulse current in power frequency communication according to claim 1, characterized in that: The step of power frequency voltage signal modulation coding includes the following steps: Identify the zero-crossing point information in real time according to the power frequency voltage zero-crossing detection circuit; Receive and wait for the start power frequency voltage modulation command from the upper-level terminal. If the start modulation command is received, read the currently stored power frequency voltage modulation phase angle in the memory and control the power frequency voltage modulation circuit to perform modulation; According to a certain modulation and coding method, the power frequency voltage is modulated in sequence until all the coded information representing the identification code or device address is sent.

3. The method for adaptively and dynamically adjusting distorted pulse current in power frequency communication according to claim 1 or claim 2, characterized in that: The power frequency voltage modulation phase angle ranges from 5.4 degrees to 16.2 degrees.

4. The method for adaptively adjusting distorted pulse current in power frequency communication according to claim 1 or claim 2, characterized in that: In the set time period, the power frequency voltage modulation phase angle is first defaulted to 10.8 degrees.

5. The method for adaptively and dynamically adjusting distorted pulse current in power frequency communication according to claim 1, characterized in that: The steps of extracting and identifying the effective distorted pulse current signal and demodulating the coded information include the following steps: According to the characteristics of power frequency voltage modulation using the voltage waveform zero-crossing region modulation, a detection time window is set near the voltage zero-crossing point, and the original load current data within the corresponding time window is analyzed; Calculate the amplitude of the pulse current signal within each current cycle detection time window; The amplitude of the distorted pulse current signal extracted and calculated within each current cycle detection time window is compared with the set threshold recognition threshold. If it is greater than the threshold recognition threshold, the distorted pulse current signal is judged as a valid distorted pulse current signal; if the amplitude of the distorted pulse current signal extracted and calculated is less than the set threshold, it is judged as an invalid distorted pulse current signal; Each effective distorted pulse current signal is demodulated according to the set coding rule to identify the coding information.

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