Power information cooperative modulation method based on buck DC converter

Abstract

The invention discloses a power information cooperative modulation method based on a buck DC converter, and relates to the technical field of power information cooperative modulation. According to the method, power information cooperative modulation is carried out by combining the structural characteristics of the three-phase interleaving buck type direct-current converter, the amplitude and phase characteristics of output voltage ripples are changed by adjusting the carrier phase offset according to the inherent phase relation that three phases of the three-phase interleaving buck type direct-current converter are interleaved by 120 degrees, and modulation of information coding is achieved. Unification of the phase shift keying switching frequency is realized, the performance of power transmission and information interaction is improved, and the ripple amplitude fluctuation range is relatively small. When a plurality of converters operate in parallel, the ripple amplitude of the converter in a non-communication state approaches zero, so that interference on information demodulation of the converter at a communication end can be avoided, an orthogonal switching frequency switching strategy does not need to be adopted, the system complexity is effectively reduced, and the applicability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power information collaborative modulation, and particularly relates to a power information collaborative modulation method based on a buck DC converter. Background Art

[0002] Currently, in power signal dual modulation (PSDM), information is injected into a carrier wave or a reference wave, so that information transmission is coordinated with power modulation, and the information is also modulated into a pulse width modulation (PWM) waveform. After power demodulation by a converter filter, the information is carried by the output voltage ripple, realizing the transmission of information carried by the original ripple of the converter.

[0003] The current power information collaborative modulation technology is mainly oriented to basic DC-DC converter topologies, such as boost converters and buck converters. In the prior art, power information collaborative modulation methods are applied to simple DC-DC converters, and the modulation methods include phase shift keying (PSK), frequency shift keying (FSK), and amplitude shift keying (ASK).

[0004] However, when using PSK or FSK, it is necessary to rely on dynamic frequency modulation (hopping to an orthogonal frequency) to avoid ripple interference in the scenario of multiple converters in parallel, resulting in the discretization of the switching frequency, increasing the design complexity and volume cost of the filter circuit. Moreover, the existing methods use the output ripple as the information carrier and do not actively suppress the ripple during the modulation process. For the encoding of "1" in the information encoding, it is necessary to artificially increase the ripple amplitude. Taking ASK as an example, it realizes encoding by periodically switching the duty cycle, resulting in an enlarged fluctuation range of the ripple amplitude and deteriorating the power quality.

[0005] In summary, the existing power information collaborative modulation methods have a relatively large fluctuation range of the ripple amplitude and are less applicable in the scenario of multiple converters in parallel. Summary of the Invention

[0006] Based on this, it is necessary to provide a power information collaborative modulation method based on a buck DC converter for the above technical problems.

[0007] The present invention adopts the following technical solutions: The present invention provides a method for collaborative modulation of power information based on a buck DC converter, which is a three-phase interleaved parallel buck DC converter and includes three parallel Buck circuits; the present invention first represents the information to be transmitted through four different information encodings, and then controls the switching tubes of the three Buck circuits to transmit the information to be transmitted while realizing power conversion; wherein, the initial carrier phase of the first Buck circuit is kept at 0°, the initial carrier phase of the second Buck circuit is switched between 120° and 0°, and the initial carrier phase of the third Buck circuit is switched between 240° and 0°, so as to modulate the four different information encodings into the output voltage ripple of the three-phase interleaved parallel buck DC converter.

[0008] The present invention provides a device for collaborative modulation of power information based on a buck DC converter, including: An encoding module, configured to represent the information to be transmitted through four different information encodings; A control module, configured to control the switching tubes of the three Buck circuits to transmit the information to be transmitted while realizing power conversion; A three-phase interleaved parallel buck DC converter, configured to keep the initial carrier phase of the first Buck circuit at 0° under the control of the control module, switch the initial carrier phase of the second Buck circuit between 120° and 0°, and switch the initial carrier phase of the third Buck circuit between 240° and 0°, so as to modulate the four different information encodings into the output voltage ripple of the three-phase interleaved parallel buck DC converter.

[0009] The above at least one technical solution adopted by the present invention can achieve the following beneficial effects: The present invention combines the structural characteristics of the three-phase interleaved parallel buck DC converter itself to perform collaborative modulation of power information. Utilizing the inherent phase relationship of 120° interleaving of the three phases of the three-phase interleaved parallel buck DC converter, the amplitude and phase characteristics of the output voltage ripple are changed by adjusting the carrier phase offset amount to realize the modulation of information encoding.

[0010] Compared with the traditional applications of collaborative modulation of power information that all use ripples to transmit information, when the present invention transmits the default information encoding in the default state, the ripple superposition effect under the 120° interleaving condition of the three phases makes its amplitude greatly reduced. When transmitting other information symbols, switching the carrier phase of any one phase breaks the phase collaborative balance, increases the total ripple amplitude, and changes the fundamental frequency phase, so as to perform information modulation, realize the unity of the phase shift keying switching frequency, improve the performance of power transmission and information interaction, and the ripple amplitude fluctuation range is small.

[0011] When multiple converters operate in parallel, the converters in the non-communication state can avoid interfering with the information demodulation of the converters at the communication end because the ripple amplitude approaches zero. There is no need to adopt the orthogonal switching frequency switching strategy, which effectively reduces the system complexity and improves the applicability. Description of the Drawings

[0012] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 It is a schematic flow chart of a power information cooperative modulation method based on a buck DC converter provided by the present invention; Figure 2 It is a schematic diagram of the topology structure of a three-phase interleaved parallel buck DC converter provided by the present invention; Figure 3 It is a schematic diagram of a three-phase interleaved 120° drive waveform and three-phase inductor current waveforms provided by the present invention; Figure 4 It is a schematic diagram of a three-phase non-interleaved 120° drive waveform and three-phase inductor current waveforms provided by the present invention; Figure 5 It is a schematic diagram of an information demodulation process provided by the present invention. Detailed Embodiments

[0013] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0014] Currently, existing solutions directly rely on the inherent ripple of the converter as the information carrier. Taking ASK modulation as an example, the encoding of information "1" requires artificially increasing the ripple amplitude, and the ripple amplitude fluctuates within a large range. Moreover, in order to achieve independent information transmission in the scenario of multiple buck converters (Buck converters) in parallel, the PSK or FSK modulation of existing solutions needs to switch to orthogonal frequencies to avoid the ripple interference of other converters.

[0015] The present invention proposes a ripple-information collaborative modulation method based on a three-phase interleaved parallel Buck converter. The three-phase interleaved phase of 120° is utilized to reduce the ripple magnitude, and at the same time, the ripple amplitude is used for demodulation. When transmitting the default information code "0", the ripple superposition effect under the three-phase interleaved 120° condition greatly reduces its amplitude. When transmitting other information codes, the carrier phase of any one phase is switched, breaking the phase collaborative balance, causing the total ripple amplitude to suddenly increase and the fundamental frequency phase to change, thereby performing information demodulation, achieving the unification of the phase-shift keying switching frequency, simplifying the filter conditioning circuit, and improving the performance of power transmission and information interaction.

[0016] The following will, in conjunction with the accompanying drawings, elaborate in detail on the technical solutions provided by the embodiments of the present invention.

[0017] Figure 1 It is a schematic flow diagram of a power information collaborative modulation method based on a buck-type DC converter in the present invention. The buck-type DC converter is a three-phase interleaved parallel buck-type DC converter, and specifically includes the following steps: S101: Represent the information to be transmitted using four different information codes.

[0018] S102: Through the control of the switching tubes of the three Buck circuits, while realizing power conversion, transmit the information to be transmitted.

[0019] The present invention performs power information collaborative modulation based on a three-phase interleaved parallel buck-type DC converter (Three-Phase Interleaved Buck Converter, 3P-IBC). Figure 2 It is a schematic diagram of the topology structure of a three-phase interleaved parallel buck-type DC converter in the present invention. Figure 2 It can be seen that it includes three parallel Buck circuits. The conduction phases of the switching tubes of each phase Buck circuit differ by 120° in sequence. This interleaved control method can effectively reduce the output voltage and current ripple, reduce the volume of the filter inductance and capacitance, and greatly improve the power density. At the same time, since it is three-phase parallel, each phase only needs to bear one-third of the total current, reducing the current stress requirements of the switching devices.

[0020] The present invention first models the information modulation of the three-phase interleaved parallel buck-type DC converter. For example, taking the duty cycle D =0.5 as an example, when the PWM waveforms of the 3P-IBC are three-phase interleaved by 120°, the driving waveforms and the three-phase inductor current waveforms are as Figure 3 shown. Figure 3 It is a schematic diagram of a three-phase interleaved 120° driving waveform and three-phase inductor current waveforms in the present invention.

[0021] Taking the first Buck circuit as branch 1, the second Buck circuit as branch 2, and the third Buck circuit as branch 3, denote the PWM waveform of branch 1 as d 1 , the PWM waveform of branch 2 as d 2 , the PWM waveform of branch three as d 3 , the current flowing through branch 1 as i L1 , the current flowing through branch 2 as i L2 , the current flowing through branch 3 as i L3 , and the sum of the three branches is i L . When the PWM signals of the three-phase branches are staggered by 120°, the inductor current waveform is as shown in Figure 3 . When t is t 0 ~t 1 period, the three-phase inductor voltage expression: .

[0022] In the formula, is the input voltage of the Buck circuit, is the output voltage of the Buck circuit, is the inductance value of branch 1, is the inductance value of branch 2, is the inductance value of branch 3.

[0023] According to the relationship between the output voltage and the input voltage of the Buck circuit: , in the formula, is the main switch closing time, is the switching period of the main switch. Based on this, the inductor current output ripple can be obtained by transforming the above formula as: .

[0024] In the formula, is the peak-to-peak current ripple flowing through the inductor L 1 under three-phase interleaving, is the peak-to-peak current ripple flowing through the inductor L 2 under three-phase interleaving, is the peak-to-peak current ripple flowing through the inductor L 3 under three-phase interleaving.

[0025] According to the KCL theorem, and L1 = L 2 = L 3 = L It can be deduced that the total peak-to-peak current ripple is: 。

[0026] In the formula, is the total peak-to-peak current ripple under three-phase interleaving.

[0027] When the PWM waveforms of 3P-IBC are not three-phase interleaved, the inductor current waveform is as Figure 4 shown, Figure 4 which is a schematic diagram of a three-phase non-interleaved 120° drive waveform and a three-phase inductor current waveform in the present invention.

[0028] When t is t 0 ~ t 1 time period, the three-phase inductor voltage expression is: 。

[0029] Similarly, according to the relationship between the output voltage and the input voltage of the Buck circuit, the above formula can be transformed to obtain the output ripple of the inductor current as: 。

[0030] In the formula, is the peak-to-peak current flowing through inductor L 1 under three-phase non-interleaving, is the peak-to-peak current flowing through inductor L 2 under three-phase non-interleaving, is the peak-to-peak current flowing through inductor L 3 under three-phase non-interleaving.

[0031] According to the KCL theorem, it can be deduced that the total peak-to-peak current ripple is: 。

[0032] In the formula, is the total peak-to-peak current ripple under three-phase non-interleaving.

[0033] Compare the ripple magnitudes in the two cases of three-phase interleaving and three-phase non-interleaving. , information modulation is performed accordingly. When transmitting the information code "0", the three-phase is staggered by 120°. When transmitting an information code other than "0" (assuming the phases of the three-phase PWM control signals are 0°, 0°, 0° corresponding to the information code "3"), the three-phase is not staggered. Therefore, the ripple amplitude becomes larger, and the increased ripple amplitude can be recognized to demodulate the information in the ripple.

[0034] Similarly, it can be calculated that when the phases of the three-phase PWM control signals are 0°, 120°, 0° or 0°, 0°, 240°, the ripple amplitude sizes are all: .

[0035] Therefore, for information modulation modeling, the phase switching of the three-phase branch PWM signals is shown in Table 1. Table 1 is a schematic table of the PWM phases corresponding to an information code in the present invention.

[0036] Table 1 PWM Phases Corresponding to Information Codes

[0037] Based on the information modulation modeling process, the power information collaborative modulation method based on the buck-type DC converter proposed in the present invention can be further obtained. First, the information to be transmitted is represented by four different information codes, and then by controlling the switching tubes of the three Buck circuits, while realizing power conversion, the information to be transmitted is transmitted. Among them, the initial phase of the carrier of the first Buck circuit is kept at 0°, the initial phase of the carrier of the second Buck circuit is switched between 120° and 0°, and the initial phase of the carrier of the third Buck circuit is switched between 240° and 0°, so as to modulate the four different information codes into the output voltage ripple of the three-phase interleaved parallel buck-type DC converter. The statement that the information to be transmitted is represented by four different information codes does not mean that each piece of information to be transmitted has to be represented by all four information codes. It can be represented by four or less than four. How many information codes are specifically used for each piece of information to be transmitted can be determined according to the specific content of the information to be transmitted and the coding dictionary used. The present invention does not limit this.

[0038] Based on the above Table 1, in one or more embodiments of the present invention, the four different information codes may include: information code "0", information code "1", information code "2", and information code "3".

[0039] When the initial phase of the carrier of the first Buck circuit is 0°, the initial phase of the carrier of the second Buck circuit is 120°, and the initial phase of the carrier of the third Buck circuit is 240°, the information code "0" is modulated into the output voltage ripple of the three-phase interleaved parallel buck-type DC converter.

[0040] When the carrier initial phase of the first Buck circuit is 0°, the carrier initial phase of the second Buck circuit is 0°, and the carrier initial phase of the third Buck circuit is 0°, the information code "3" is modulated into the output voltage ripple of the three-phase interleaved parallel buck DC converter.

[0041] When the carrier initial phase of the first Buck circuit is 0°, the carrier initial phase of the second Buck circuit is 120°, and the carrier initial phase of the third Buck circuit is 0°, the information code "1" is modulated into the output voltage ripple of the three-phase interleaved parallel buck DC converter.

[0042] When the carrier initial phase of the first Buck circuit is 0°, the carrier initial phase of the second Buck circuit is 0°, and the carrier initial phase of the third Buck circuit is 240°, the information code "2" is modulated into the output voltage ripple of the three-phase interleaved parallel buck DC converter.

[0043] Furthermore, in one or more embodiments of the present invention, the four information codes "0", "1", "2", and "3" can be represented by two-bit binary codes in computer binary coding, which are respectively represented as "00", "01", "10", and "11". Of course, more binary bits can also be used for representation, and the present invention does not limit this.

[0044] Based on the above information modulation process, information demodulation modeling is carried out. Before signal judgment, the output voltage of the three-phase interleaved parallel buck DC converter on the bus needs to be conditioned by a signal conditioning circuit into a sinusoidal fundamental wave with an appropriate DC bias carrying information. For the design of the signal conditioning circuit, a capacitor should be used to block the DC and leave the ripple first. Since the ripple amplitude is small, it needs to be amplified by a signal amplifier and then followed by band-pass filtering to obtain a sinusoidal signal with the amplified information-carrying switching frequency.

[0045] It can be obtained from the analysis of information modulation modeling that when the transmitted information codes are "0" and "3", the ripple amplitudes of the two are different and different from "1" and "2", so an amplitude demodulation method can be adopted to distinguish the two. However, for the information codes "1" and "2", their ripple amplitudes are the same, and it is easy to be confused by taking amplitude demodulation. Therefore, phase demodulation will be combined for processing. The following models the demodulation of the 4 information codes.

[0046] The demodulation principle is as Figure 5 shown, Figure 5 which is a schematic diagram of an information demodulation process in the present invention. The conditioned signal is respectively passed through amplitude demodulation and phase coherent demodulation.

[0047] Specifically, in one or more embodiments of the present invention, the information receiver may first receive the output voltage of the three-phase interleaved buck DC converter, filter out the DC component of the output voltage through a capacitor to obtain a ripple signal, then amplify and filter the ripple signal through a signal amplifier and a band-pass filter to obtain a switching frequency fundamental signal carrying information encoding, then perform amplitude extraction and judgment on the switching frequency fundamental signal through an amplitude extractor and a judge to obtain a first demodulation information, and perform coherent demodulation on the switching frequency fundamental signal through a phase coherent demodulator to obtain a second demodulation information. Finally, the first demodulation information and the second demodulation information may be added together to obtain the transmitted information encoding.

[0048] For example, first, through the amplitude extractor, the value of the basic signal is sampled every 2 microseconds within a switching frequency period, and its maximum value, that is, the amplitude of the fundamental signal, is extracted and compared, and then passed through the judge. Since the amplitude of the fundamental signal when transmitting the information encoding "3" is much larger than that of the fundamental signal when transmitting the information encoding "0", the information encodings of "0" and "3" can be demodulated therefrom. Because the ripple voltage waveforms when transmitting the information encoding "1" and the information encoding "2" are mirror-symmetrical within a switching period, the information encodings of "1" and "2" are obtained by using the conditioned signal through a phase coherent demodulator. The amplitude demodulation and the coherent demodulation are performed simultaneously, and finally the demodulation results of the two are added together to obtain the transmitted information encoding.

[0049] Combined with the information modulation and demodulation processes of the information sender and the information receiver, the present invention also provides a modulation and demodulation implementation method for the information sender and the information receiver, including: Step 1: The information sender represents the information to be transmitted through four different information encodings, and continues to take the above-mentioned two-bit binary encoding representing 4 information encodings as an example for illustration. By controlling the switching tubes of the three Buck circuits, the initial phase of the carrier wave of branch 1 of the 3P-IBC is always kept at 0°, and the initial phase of the carrier wave of branch 2 switches between 120° and 0°, that is, the high-order information 0 and 1 are expressed, and the initial phase of the carrier wave of branch 3 switches between 240° and 0°, expressing the low-order information 0 and 1. While realizing the power conversion of the 3P-IBC, the four information encodings "0", "1", "2" and "3" are modulated into the output voltage ripple.

[0050] Step 2: The information receiver conditions the output voltage waveform of the 3P-IBC. First, the DC is filtered out by a capacitor, and then through a signal amplifier and a band-pass filter, a switching frequency fundamental signal carrying information encoding is obtained.

[0051] Step 3: The information receiver inputs the conditioned switching frequency fundamental signal into an amplitude extractor and a judge to obtain a first demodulation information corresponding to the information encoding "0" or "3".

[0052] Step 4: The information receiver passes the conditioned switching frequency fundamental frequency signal through a phase coherent demodulator to obtain a second demodulated information corresponding to the information code "1" or "2".

[0053] Step 5: The information receiver adds the first demodulated information and the second demodulated information demodulated by the two regulators to obtain the final information code, realizing the power information cooperative modulation of 3P-IBC.

[0054] Based on Figure 1 The power information cooperative modulation method based on the buck DC converter shown, the present invention combines the structural characteristics of the three-phase interleaved parallel buck DC converter itself for power information cooperative modulation, utilizes the inherent phase relationship of 120° three-phase interleaving of the three-phase interleaved parallel buck DC converter, and changes the amplitude and phase characteristics of the output voltage ripple by adjusting the carrier phase offset amount to realize the modulation and demodulation of information coding.

[0055] Compared with the traditional power information cooperative modulation applications that all use ripples to transmit information, when the present invention transmits the default information code in the default state, the ripple superposition effect under the 120° three-phase interleaved condition greatly reduces its amplitude. When transmitting other information symbols, switching the carrier phase of any one phase breaks the phase cooperation balance, increases the total ripple amplitude, and changes the fundamental frequency phase, thereby performing information modulation and demodulation, realizing the unification of the phase shift keying switching frequency, improving the performance of power transmission and information interaction, and the ripple amplitude fluctuation range is small.

[0056] When multiple converters operate in parallel, the converters in the non-communication state have a ripple amplitude approaching zero, which can avoid interfering with the information demodulation of the communication-end converter, and there is no need to adopt an orthogonal switching frequency switching strategy, effectively reducing the system complexity and improving the applicability.

[0057] When applying the power information cooperative modulation method based on the buck DC converter provided by the present invention, it is not necessary to execute according to Figure 1 the order of the steps shown. The specific execution order of each step can be determined according to needs, and the present invention does not limit this.

[0058] The above is the power information cooperative modulation method based on the buck DC converter provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding power information cooperative modulation device based on the buck DC converter, which is applied to the information sender. The device includes: An encoding module for representing the information to be transmitted through four different information codes; A control module for realizing power conversion and transmitting the information to be transmitted while controlling the switching tubes of the three Buck circuits; A three-phase interleaved buck DC converter is used to keep the initial carrier phase of the first Buck circuit at 0° under the control of a control module, make the initial carrier phase of the second Buck circuit switch between 120° and 0°, and make the initial carrier phase of the third Buck circuit switch between 240° and 0°, so as to encode and modulate four different pieces of information into the output voltage ripple of the three-phase interleaved buck DC converter.

[0059] Based on the same idea, the present invention also provides a corresponding power information cooperative modulation device based on a buck DC converter, which is applied to an information receiver. The device includes: a capacitor, a signal amplifier, a band-pass filter, an amplitude extractor, a discriminator, a phase coherent demodulator, and an addition module; The input ends of the capacitor, the signal amplifier, and the band-pass filter are connected in series in sequence. The first output end of the band-pass filter is connected to the input ends of the amplitude extractor and the discriminator in sequence. The second output end of the band-pass filter is connected to the input end of the phase coherent demodulator. The output ends of the discriminator and the phase coherent demodulator are respectively connected to two input ends of the addition module; The capacitor is used to receive the output voltage of the three-phase interleaved buck DC converter, filter out the DC part of the output voltage, and obtain a ripple signal; The signal amplifier and the band-pass filter are used to amplify and filter the ripple signal to obtain a switching frequency fundamental frequency signal carrying information coding; The amplitude extractor and the discriminator are used to extract and judge the amplitude of the switching frequency fundamental frequency signal to obtain a first demodulation information; The phase coherent demodulator is used to perform coherent demodulation on the switching frequency fundamental frequency signal to obtain a second demodulation information; The addition module is used to add the first demodulation information and the second demodulation information to obtain the transmitted information coding.

[0060] For the specific limitations on the power information cooperative modulation device based on a buck DC converter, reference can be made to the limitations on the power information cooperative modulation method based on a buck DC converter in the above text, which will not be elaborated here. Each module in the above power information cooperative modulation device based on a buck DC converter can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in the processor of the computer device in hardware form or be independent of it, or be stored in the memory of the computer device in software form, so as to facilitate the processor to call and execute the operations corresponding to the above-mentioned modules.

[0061] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided by the present invention can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0062] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope recorded by the present invention.

Claims

1. A power information coordinated modulation method based on a step-down DC converter, characterized in that: The step-down DC converter is a three-phase staggered parallel step-down DC converter, which includes three Buck circuits connected in parallel; the method includes: The information to be transmitted is represented by four different information codes; By controlling the three Buck circuit switch tubes, power conversion is achieved while transmitting the information to be transmitted; Among them, the initial phase of the carrier of the first Buck circuit is maintained at 0°, the initial phase of the carrier of the second Buck circuit is switched between 120° and 0°, and the initial phase of the carrier of the third Buck circuit is switched between 240° and 0°, so as to modulate four different information codes into the output voltage ripple of the three-phase interleaved parallel buck DC converter.

2. The power information coordinated modulation method based on a step-down DC converter according to claim 1, characterized in that: The four different information codes include: information code "0", information code "1", information code "2" and information code "3"; When the initial phase of the carrier of the first Buck circuit is 0°, the initial phase of the carrier of the second Buck circuit is 120°, and the initial phase of the carrier of the third Buck circuit is 240°, the information code "0" is modulated into the output voltage ripple of the three-phase interleaved parallel buck DC converter; When the initial phase of the carrier of the first Buck circuit is 0°, the initial phase of the carrier of the second Buck circuit is 0°, and the initial phase of the carrier of the third Buck circuit is 0°, the information code "3" is modulated into the output voltage ripple of the three-phase interleaved parallel buck DC converter; When the initial phase of the carrier of the first Buck circuit is 0°, the initial phase of the carrier of the second Buck circuit is 120°, and the initial phase of the carrier of the third Buck circuit is 0°, the information code "1" is modulated into the output voltage ripple of the three-phase interleaved parallel buck DC converter; When the initial phase of the carrier of the first Buck circuit is 0°, the initial phase of the carrier of the second Buck circuit is 0°, and the initial phase of the carrier of the third Buck circuit is 240°, the information code "2" is modulated into the output voltage ripple of the three-phase interleaved parallel buck DC converter.

3. The power information coordinated modulation method based on a step-down DC converter according to claim 1, characterized in that: The method further comprises: The information receiver receives the output voltage of the three-phase staggered parallel buck DC converter, filters out the DC part of the output voltage through a capacitor, and obtains a ripple signal; The information receiver amplifies and filters the ripple signal through a signal amplifier and a bandpass filter to obtain a switching frequency baseband signal carrying information coding; The information receiving party extracts and determines the amplitude of the switching frequency baseband signal through the amplitude extractor and the determiner to obtain the first modulation information; the information receiving party coherently demodulates the switching frequency baseband signal through the phase coherent demodulator to obtain the second modulation information; The information receiver adds the first mediation information and the second mediation information to obtain the transmitted information code.

4. A power information cooperative modulation device, characterized in that: include: An encoding module, used for representing the information to be transmitted through four different information encodings; The control module is used to realize power conversion and transmit the information to be transmitted at the same time by controlling the three Buck circuit switch tubes; The three-phase interleaved parallel buck DC converter is used to keep the initial phase of the carrier of the first Buck circuit at 0° under the control of the control module, switch the initial phase of the carrier of the second Buck circuit between 120° and 0°, and switch the initial phase of the carrier of the third Buck circuit between 240° and 0°, so as to modulate four different information codes into the output voltage ripple of the three-phase interleaved parallel buck DC converter.

5. A power information cooperative modulation device, characterized in that: include: Capacitor, signal amplifier, bandpass filter, amplitude extractor, judger, phase coherent demodulator and adding module; The capacitor, the signal amplifier and the input end of the bandpass filter are sequentially connected in series, the first output end of the bandpass filter is sequentially connected to the input end of the amplitude extractor and the judger, the second output end of the bandpass filter is connected to the input end of the phase coherent demodulator, and the output end of the judger and the output end of the phase coherent demodulator are respectively connected to the two input ends of the adding module; The capacitor is used to receive the output voltage of the three-phase staggered parallel buck DC converter, filter out the DC part of the output voltage, and obtain a ripple signal; The signal amplifier and the bandpass filter are used to amplify and filter the ripple signal to obtain a switching frequency baseband signal carrying information coding; The amplitude extractor and the judger are used to extract and judge the amplitude of the switching frequency baseband signal to obtain the first modulation information; The phase coherent demodulator is used to coherently demodulate the switching frequency baseband signal to obtain second modulation information; The adding module is used to add the first mediation information and the second mediation information to obtain the transmitted information code.

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